bluuebunny/crossref_metadata_2025 huggingface dataset:
Autonomic Nervous System Response to Far-Infrared Sauna Exposure in Firefighters
Authors: Marciniak Rudi A , Wahl Carly A , Ebersole Kyle T
Published: September 2021

Objectives

Fire departments have employed far-infrared sauna (FIRS) use as part of post-fire call protocols to address concerns related to carcinogens. The inability of the autonomic nervous system (ANS) to fully recover following an emergency call, as demonstrated by heightened sympathetic nervous system activity and delayed parasympathetic nervous system reactivation, has been implicated as a potential factor related to sudden cardiac death. The use of a sauna post-fire call, which has been demonstrated to elevate body temperature, may interfere with the ability of the ANS to fully recover. The purpose of this study was to examine ANS responses to FIRS exposure in firefighters (FFs) with (EX) and without (NONEX) prior maximal exercise.

Methods

Sixteen career FFs participated in this study. Body temperature (TEMP), heart rate (HR), heart rate variability (HRV), blood pressure (BP), and blood lactate (La─) were measured at the start of each testing session, following a maximal exercise test (EX only), and immediately after a 15-min FIRS exposure for NONEX and EX.

Results

In NONEX, TEMP increased (P < 0.001); however, there was no change in HR, HRV, BP, or La─. In EX, BP remained unchanged while TEMP, HR, and La─ were significantly (P < 0.001) greater than baseline following FIRS exposure and HRV was significantly (P = 0.018) lower than baseline.

Conclusions

These findings indicate that FIRS following maximal exercise did support some ANS recovery, but may interfere with restoration of body temperature and parasympathetic nervous system reactivation, potentially influencing post-call cardiovascular risk in FFs.
Evolutionary diversification in the hyper-diverse montane forests of the tropical Andes: radiation ofMacrocarpaea(Gentianaceae) and the possible role of range expansion
Authors: Vieu Julien C , Hughes Colin E , Kissling Jonathan , Grant Jason R
Published: September 2021

The humid mid-elevation montane forests (MMF) of the tropical Andes harbour high levels of plant species diversity, contributing to the exceptional overall diversity of the tropical Andean biodiversity hotspot. However, little is known about the diversification dynamics of MMF plant lineages compared to lineages in other Andean biomes. Here, we use Macrocarpaea (Gentianaceae) to investigate patterns of plant diversification in the MMF, using molecular dating with fossils and secondary calibration (from a family-wide phylogenetic analysis of Gentianaceae). We sequenced 76 of 118 recognized Macrocarpaea spp. for six markers to reconstruct a time-calibrated phylogenetic tree and infer the historical biogeography of Macrocarpaea using maximum-likelihood methods implemented in BioGeoBEARS, estimating diversification rates through time and among lineages with BAMM. We document a rapid radiation of Macrocarpaea in Andean MMF coinciding with rapid colonization and range expansion across the entire distribution of the genus in the Andes starting 7.2 Mya. Our results support allopatric founder-event speciation as the dominant process contributing to geographical phylogenetic structure across the genus. We propose that establishment of the MMF in the late Miocene, when the Andes attained critical elevation to modify regional climates, provided large new areas of suitable habitat for Macrocarpaea to quickly colonize and expand through repeated founder-events. We suggest that this wave of colonization and range expansion triggered rapid diversification, and, as the MMF became progressively occupied, the diversification rate slowed. Our study also supports the idea that MMF plant radiations are older and more slowly evolving than the quickly evolving lineages in the recent Andean high-elevation grasslands.
Childhood Background Measures and Their Associations With Later-Life Physical, Mental, and Social Health in the National Social Life, Health, and Aging Project
Authors: Lee Haena , Choi Kyung Won , Waite Linda J
Published: September 2021

Objective

We describe each childhood background measure available in the National Social Life, Health, and Aging Project (NSHAP), report preliminary population estimates for each measure by age and gender, and validate the childhood measures by showing that the associations between the NSHAP childhood measures and later-life health outcomes are consistent with previous studies on this topic.

Method

Childhood background measures included family life happiness, family structure, parental educational attainment, perceived financial situation, experience of violence, witness of violence, childhood health, and place of birth. We measured self-rated health, depressive symptoms, and social support to assess later-life physical, mental, and social health. Logistic and linear regression models were used for the binary and continuous outcome variables, respectively.

Results

Older age groups were more likely than those in younger age groups to report a poor financial situation in childhood, lower parental education, and intact family structure and were less likely to have experienced or witnessed a violent event as a child. Growing up in a happy and well-educated family was associated with better physical, mental, and social health in older ages.

Discussion

NSHAP childhood data included a variety of measures assessing the family social environment during childhood, providing a valuable resource for the study of early-life determinants of health and well-being over the life course.
A North Star for Gerontology: Using the Threshold Concept Framework to Transform Ageism Education
Authors: Janssen Leah M , Flores Valerie , Cao Jiawei
Published: September 2021

Threshold concepts are fundamental to the learning process and are said to transform the way we view and understand the world around us. Although a new framework to gerontology, the threshold concept framework has been utilized in many fields inside (e.g., psychology, social work) and outside (e.g., clinical and research settings) of academia. This framework facilitates understanding learning, exposing expert blind spots, and designing curricula for complex concepts that are challenging to learn. For decades gerontologists have grappled with ageism and its dire consequences including unemployment, negative health outcomes, and rationing of health care. Education is one of, if not the most, powerful tools to combat ageism. This article demonstrates the utility of the threshold concept framework for gerontologists by conceptualizing ageism as a threshold concept. The purpose of this article is to provide an innovative approach to education on complex gerontological topics in different clinical, research, and educational settings using ageism as a primary example of a threshold concept in gerontology.
Not So Fast: Strike Kinematics of the Araneoid Trap-Jaw Spider Pararchaea alba (Malkaridae: Pararchaeinae)
Authors: Kallal Robert J , Elias Damian O , Wood Hannah M
Published: September 2021

Synopsis

To capture prey otherwise unattainable by muscle function alone, some animal lineages have evolved movements that are driven by stored elastic energy, producing movements of remarkable speed and force. One such example that has evolved multiple times is a trap-jaw mechanism, in which the mouthparts of an animal are loaded with energy as they open to a wide gape and then, when triggered to close, produce a terrific force. Within the spiders (Araneae), this type of attack has thus far solely been documented in the palpimanoid family Mecysmaucheniidae but a similar morphology has also been observed in the distantly related araneoid subfamily Pararchaeinae, leading to speculation of a trap-jaw attack in that lineage as well. Here, using high-speed videography, we test whether cheliceral strike power output suggests elastic-driven movements in the pararchaeine Pararchaea alba. The strike speed attained places P. alba as a moderately fast striker exceeding the slowest mecysmaucheniids, but failing to the reach the most extreme high-speed strikers that have elastic-driven mechanisms. Using microcomputed tomography, we compare the morphology of P. alba chelicerae in the resting and open positions, and their related musculature, and based on results propose a mechanism for cheliceral strike function that includes a torque reversal latching mechanism. Similar to the distantly related trap-jaw mecysmaucheniid spiders, the unusual prosoma morphology in P. alba seemingly allows for highly maneuverable chelicerae with a much wider gape than typical spiders, suggesting that increasingly maneuverable joints coupled with a latching mechanism may serve as a precursor to elastic-driven movements.
A Complementary, Quantitative, and Confirmatory Method to UHPLC/ESI Q-Orbitrap Screening Based on UPHLC/ESI-MS/MS for Analysis of 416 Pesticides in Fruits and Vegetables
Authors: Chow Willis , Leung Daniel , Wang Jian
Published: September 2021

Background

Triple quadrupole (MS/MS) and high-resolution mass spectrometry (HRMS), coupled with ultra-high performance (UHP) liquid chromatography (LC) or gas chromatography (GC), are technologies used to analyze pesticide residues in fruits and vegetables. LC-MS/MS has been the gold standard for analysis of pesticides, offering reliable performance and sensitivity, while LC-HRMS is expanding in application to serve as another benchmark. Method development and testing scope expansion are constantly required with new generation mass spectrometers.

Objective

This article discusses the development and validation of a quantitative and confirmatory method that can analyze over 400 pesticide residues using a state-of-the-art UHPLC/electrospray ionization (ESI)-MS/MS system.

Methods

Homogenized fruit and vegetable samples were fortified with pesticides and were extracted using a modified quick, easy, cheap, effective, rugged, and safe method. Samples were injected onto a UHPLC/ESI-MS/MS system, and data were acquired in multiple reaction monitoring (MRM) mode. The method was validated using a nested experimental design, and was able to quantify and confirm 416 pesticides in fruits and vegetables. It was also complimentary to the UHPLC/ESI Q-Orbitrap quantitative and screening methods previously developed in the authors’ laboratory.

Results

The method demonstrated good performance. In all matrixes, 92% of pesticides yielded recoveries between 81–110%, more than 95% of pesticides yielded intermediate precision ≤20%, about 65% of pesticides yielded measurement uncertainties ≤20%, and 96% of pesticides yielded measurement uncertainties ≤50%.

Conclusion

This method shows great potential to be a standalone method or as part of a laboratory workflow for quantitative and confirmatory analysis of pesticide residues in fruits and vegetables.

Highlights

This method was developed using the same mobile phases, analytical columns, and extraction procedure, as UHPLC/ESI Q-Orbitrap methods. Extracts can be run on either system, streamlining monitoring programs and offering high sample throughput.
Micronization of Thebaine Extracted from Papaver bracteatum Lindl. Using Supercritical Fluid Technology
Authors: Salehi Hamze , Karimi Mehrnaz , Raofie Farhad
Published: September 2021

Background

Thebaine, as a main opiate alkaloid extracted from Papaveraceae plants, is widely used in the synthesis of many pharmaceutical ingredients such as buprenorphine, naltrexone, naloxone, and hydrocodone. Nevertheless, thebaine and related derivatives are often insoluble in aqueous media and have low bioavailability in digestive systems.

Objective

Reducing particle size and changing the morphology can mitigate the mentioned problem. In this study, extraction of thebaine from the capsule, stem, and root of Papaver bracteatum L. was optimized and micronization of extract components was developed to study solubility.

Methods

The extraction process was performed using supercritical carbon dioxide. Experimental central composite design was employed to determine the optimal conditions. Analysis of extract was done using a validated high performance liquid chromatography method and mass spectrometry. The micronization process was performed using an inhouse developed supercritical technique. The nanoparticles were characterized using field emission scanning electron microscopy (FESEM) and ImageJ software. The effect of micronization was explored on the solubility of extract components via ultraviolet spectroscopy.

Results

The percentage of thebaine in dried capsule, stem, and root powder was about 1.05, 0.31, and 0.83% respectively. The extraction results indicate that supercritical pressure has the greatest effect on the extraction yield. Analysis of FESEM images revealed that nanoparticles of extract components with particle size distribution of 5–100 nm were collected successfully.

Conclusion

The extraction results indicate that pressure has the greatest effect on the extraction yield. In vitro studies illustrated that the solubility of extract components increased up to 1.7 times during the micronization process.

Highlights

Expansion of supercritical methods as an effective method was performed for extracting and preparing alkaloid nanoparticles. This process led to improved oral bioavailability of alkaloids.
Comparisons of photosynthesis-related traits among understory lichens, mosses and vascular plant leaves in a high-elevation subalpine forest
Authors: Wang Zhe , Liu Xin , Zhu Zhangming , Ma Wenzhang , Bao Weikai
Published: September 2021

Many mosses and lichens thrive in high-elevation subalpine forests and even become dominant species on the forest floor. Although they play an irreplaceable ecological role in the forest, less is known about their eco-physiological status, and how their photosynthesis-related functional traits differ from those of co-occurring vascular plants. We determined the carbon, nitrogen and phosphorus concentrations and stoichiometric ratios, tissue mass per area, chlorophyll concentrations and photosynthetic light–response curves of three lichens, three mosses and four vascular plants in a subalpine forest in the eastern Tibetan Plateau of China. Trait values were compared among and within each group. The lichens possessed a higher nitrogen concentration than that of mosses. In addition, the two poikilohydric groups exhibited lower concentrations of nitrogen, phosphorus and chlorophyll, light-saturated assimilation rates and photosynthetic nutrient use efficiencies, and higher light compensation points than those of vascular plant leaves. Furthermore, variations in photosynthesis-related traits for lichen species reflect their different adaptation strategies to their corresponding environments. In contrast, the differences were weak among the three forest-floor mosses and the three herb species. These results demonstrate that the high abundance of understory lichens and mosses in the high-elevation subalpine forest cannot be explained by the photosynthesis-related traits.
Creating Uncertainty in the Governance of Arrival and Return: Target-group Constructions in Bavarian AnkER Facilities
Authors: Münch Sybille
Published: September 2021

Germany remains the number one destination for migrants in Europe. After 2015, following a backlash, burdens on municipalities and the inefficiency of the processing of asylum claims were widely problematized, as was the termination of residence and return of those deemed irregular migrants. Policymakers presented so-called AnkER centres, an acronym for central reception, decision-making, and repatriation facilities that translates as ‘anchor’ in German, as a solution that would accelerate procedures. Drawing from an interpretive case study of the AnkER pilots in Bavaria/Germany, we scrutinize meaning-making as reflected in contested constructions of target groups and identify the complex rationales of belonging shared by different ‘communities of meaning’ that pose a challenge to the promise of certainty declared in official documents.
The challenge of simultaneously matching the observed diversity of chemical abundance patterns in cosmological hydrodynamical simulations
Authors: Buck Tobias , Rybizki Jan , Buder Sven , Obreja Aura , Macciò Andrea V , Pfrommer Christoph , Steinmetz Matthias , Ness Melissa
Published: September 2021

With the advent of large spectroscopic surveys the amount of high quality chemodynamical data in the Milky Way (MW) increased tremendously. Accurately and correctly capturing and explaining the detailed features in the high-quality observational data is notoriously difficult for state-of-the-art numerical models. In order to keep up with the quantity and quality of observational data sets, improved prescriptions for galactic chemical evolution need to be incorporated into the simulations. Here we present a new, flexible, time-resolved chemical enrichment model for cosmological simulations. Our model allows us to easily change a number of stellar physics parameters such as the shape of the initial mass function (IMF), stellar lifetimes, chemical yields, or SN Ia delay times. We implement our model into the Gasoline2 code and perform a series of cosmological simulations varying a number of key parameters, foremost evaluating different stellar yield sets for massive stars from the literature. We find that total metallicity, total iron abundance, and gas phase oxygen abundance are robust predictions from different yield sets and in agreement with observational relations. On the other hand, individual element abundances, especially alpha-elements show significant differences across different yield sets and none of our models can simultaneously match constraints on the dwarf and MW mass scale. This offers a unique way of observationally constraining model parameters. For MW mass galaxies we find for most yield tables tested in this work a bimodality in the [α/Fe] versus [Fe/H] plane of rather low intrinsic scatter potentially in tension with the observed abundance scatter.
Outflows from starburst galaxies with various driving mechanisms and their X-ray properties
Authors: Yu B P Brian , Owen Ellis R , Pan Kuo-Chuan , Wu Kinwah , Ferreras Ignacio
Published: September 2021

Outflows in starburst galaxies driven by thermal-mechanical energy, cosmic rays, and their mix are investigated with 1D and 2D hydrodynamic simulations. We show that these outflows could reach a stationary state, after which their hydrodynamic profiles asymptotically approach previous results obtained semi-analytically for stationary outflow configurations. The X-rays from the simulated outflows are computed, and high-resolution synthetic spectra and broad-band light curves are constructed. The simulated outflows driven by thermal mechanical pressure and CRs have distinguishable spectral signatures, in particular, in the sequence of the keV K α lines of various ions and in the L-shell Fe emission complex. We demonstrate that broad-band colour analysis in X-rays is a possible alternative means to probe outflow driving mechanisms for distant galaxies, where observations may not be able to provide sufficient photons for high-resolution spectroscopic analyses.
An unbiased estimator of the full-sky CMB angular power spectrum at large scales using neural networks
Authors: Chanda Pallav , Saha Rajib
Published: September 2021

Accurate estimation of the cosmic microwave background (CMB) angular power spectrum is enticing due to the prospect for precision cosmology it presents. Galactic foreground emissions, however, contaminate the CMB signal and need to be subtracted reliably in order to lessen systematic errors on the CMB temperature estimates. Typically, bright foregrounds in a region lead to further uncertainty in temperature estimates in the area even after some foreground removal technique is performed and hence determining the underlying full-sky angular power spectrum poses a challenge. We explore the feasibility of utilizing artificial neural networks to predict the angular power spectrum of the full-sky CMB temperature maps from the observed angular power spectrum of the partial sky in which CMB temperatures in some bright foreground regions are masked. We present our analysis at large angular scales with two different masks. We produce unbiased predictions of the full-sky angular power spectrum and recover the underlying theoretical power spectrum using neural networks. Our predictions are also uncorrelated to a large extent. We further show that the multipole-space covariances of the predictions of full-sky spectra made by the artificial neural networks are much smaller than those of the estimates obtained using the pseudo-Cℓ method.
Haemophagocytic lymphohistiocytosis in a patient with familial Mediterranean fever and miliary tuberculosis: a case report
Authors: Cerme Emir , Oztas Mert , Balkan Ilker Inanc , Cetin Esin Aktas , Ugurlu Serdal
Published: September 2021

Haemophagocytic lymphohistiocytosis (HLH) is a lethal complication of several infections, especially viral origin. Mycobacterium tuberculosis infection can also lead to HLH, yet it is an uncommon trigger. Considering the role of increased cytokines in HLH, autoinflammatory conditions, such as familial Mediterranean fever (FMF), might contribute to its development. Nevertheless, the possible relationship between FMF and HLH has been suggested only in some case reports. We present a case of FMF who admitted to the hospital with consitutional symptoms and chest pain regarding to recurrent pericarditis. On a blood test, pancytopenia and elevated acute phase reactants were seen. Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography demonstrated positive FDG uptake sites on both the right and left surrenal glands, the visceral layer of pericard, and reactive lymphadenomegalies at multiple mediastinal regions. Bone marrow biopsy revealed haemophagocytosis. Methylprednisolone treatment was initiated. Despite immunosuppressive treatment, clinical and biochemical parameters deteriorated; thus, a thorax computed tomography was executed. Findings were consistent with miliary tuberculosis infection. M. tuberculosis was detected in blood culture and bronchoalveolar lavage culture material. Also, bone marrow and surrenal biopsy material revealed necrotising caseating granuloma.
Phase and amplitude electroencephalography correlations change with disease progression in people with idiopathic rapid eye-movement sleep behavior disorder
Authors: Roascio Monica , Canessa Andrea , Trò Rosella , Mattioli Pietro , Famà Francesco , Giorgetti Laura , Girtler Nicola , Orso Beatrice , Morbelli Silvia , Nobili Flavio , Arnaldi Dario , Arnulfo Gabriele
Published: September 2021

Study Objectives

Increased phase synchronization in electroencephalography (EEG) bands might reflect the activation of compensatory mechanisms of cognitive decline in people with neurodegenerative diseases. Here, we investigated whether altered large-scale couplings of brain oscillations could be linked to the balancing of cognitive decline in a longitudinal cohort of people with idiopathic rapid eye-movement sleep behavior disorder (iRBD).

Methods

We analyzed 18 patients (17 males, 69.7 ± 7.5 years) with iRBD undergoing high-density EEG (HD-EEG), presynaptic dopaminergic imaging, and clinical and neuropsychological (NPS) assessments at two time points (time interval 24.2 ± 5.9 months). We thus quantified the HD-EEG power distribution, orthogonalized amplitude correlation, and weighted phase-lag index at both time points and correlated them with clinical, NPS, and imaging data.

Results

Four patients phenoconverted at follow-up (three cases of parkinsonism and one of dementia). At the group level, NPS scores decreased over time, without reaching statistical significance. However, alpha phase synchronization increased and delta amplitude correlations decreased significantly at follow-up compared to baseline. Both large-scale network connectivity metrics were significantly correlated with NPS scores but not with sleep quality indices or presynaptic dopaminergic imaging data.

Conclusions

These results suggest that increased alpha phase synchronization and reduced delta amplitude correlation may be considered electrophysiological signs of an active compensatory mechanism of cognitive impairment in people with iRBD. Large-scale functional modifications may be helpful biomarkers in the characterization of prodromal stages of alpha-synucleinopathies.
The impact of global lineage dynamics, border restrictions, and emergence of the B.1.1.7 lineage on the SARS-CoV-2 epidemic in Norway
Authors: Osnes Magnus N , Alfsnes Kristian , Bråte Jon , Garcia Ignacio , Riis Rasmus K , Instefjord Kamilla H , Elshaug Hilde , Vollan Hilde S , Moen Line Victoria , Pedersen Benedikte Nevjen , Caugant Dominique A , Stene-Johansen Kathrine , Hungnes Olav , Bragstad Karoline , Brynildsrud Ola , Eldholm Vegard
Published: September 2021

As the COVID-19 pandemic swept through an immunologically naïve human population, academics and public health professionals scrambled to establish methods and platforms for genomic surveillance and data sharing. This offered a rare opportunity to study the ecology and evolution of SARS-CoV-2 over the course of the ongoing pandemic. Here, we use population genetic and phylogenetic methodology to characterize the population dynamics of SARS-CoV-2 and reconstruct patterns of virus introductions and local transmission in Norway against this backdrop. The analyses demonstrated that the epidemic in Norway was largely import driven and characterized by the repeated introduction, establishment, and suppression of new transmission lineages. This pattern changed with the arrival of the B.1.1.7 lineage, which was able to establish a stable presence concomitant with the imposition of severe border restrictions.
Anatomy of a Business Case
Authors: Welch Teresa D. , Smith Todd B.
Published: September 2021

A business case plan (BCP) provides a structured framework for evidence-based, transparent business decisions. It is an essential tool that when written well will provide you with the means to translate the cost and benefits of nursing practice proposals, often related in anecdotal terms, into quantifiable, evidence-based terms outlining return on investment and business advantages of investing in nursing initiatives. The BCP should include an analysis of the problem and associated needs, the proposed solutions with options, goals for success, implementation, and evaluation plans, as well as a risk-adjusted cost-benefit analysis. It contains the necessary information to allow decision makers to make well-informed decisions regarding resource allocation. As clinical experts seeking to compete for finite resources in the health care arena, nursing leadership must bridge the language gap between nursing and business finance. This article outlines the required elements of the BCP to provide you with a practical working definition of each element to support your future initiatives in the business of health care improvement.
Palliative Care in a Pandemic
Authors: Sabolish Rachel M. , Wilson Jennifer M. , Caldwell Hollie K.
Published: September 2021

During the coronavirus disease 2019 (COVID-19) pandemic, patients experienced rapid clinical decline requiring urgent conversations about their wishes for care. Palliative care advanced practice registered nurses developed a workflow to provide early palliative care consultation to every COVID-19 patient under investigation admitted to a 368-bed acute care hospital in the United States. A retrospective exploratory study was conducted on the initial surge from March 1 to May 31 of 2020. A nonrandomized 2-group design used descriptive and inferential statistics to compare elicitation of patient care preferences for patients who received early palliative care consultation with those patients who did not receive a palliative care consult. Early palliative care consultation resulted in a higher number of patients establishing a decision-maker (99%), changing code status (46%), changing goals of care (46%), and transitioning to comfort care (24%). In those patients not receiving palliative care, fewer patients established a decision-maker (10%), changed code status (7%), changed goals of care (4%), or transitioned to comfort care (3%). During the first COVID-19 surge, early palliative care consult performed by advanced practice registered nurses resulted in a higher number of patients establishing decision-makers and changing care preferences before decompensation due to COVID-19, thus helping patients avoid potential suffering caused by unwanted medical interventions.
Data-Based Self-awareness as the Foundation for Effective Leadership
Authors: Friedman Alan , Hancock Beverly , Thompson Pamela Austin
Published: September 2021

The AONL Nurse Executive Fellowship supports nurses who are new to an executive role in developing critical executive competencies. Participants engage in an in-depth specialized assessment process to help them understand themselves and the impact on their leadership. Learnings from the 1st 2 cohorts of fellowship participants provide insight into challenges faced by new executives and how self-awareness can improve performance to address those challenges.
A signal of competitive dominance in mid-latitude herbaceous plant communities
Authors: Capitán José A. , Cuenda Sara , Ordóñez Alejandro , Alonso David
Published: September 2021

Understanding the main determinants of species coexistence across space and time is a central question in ecology. However, ecologists still know little about the scales and conditions at which biotic interactions matter and how these interact with the environment to structure species assemblages. Here we use recent theoretical developments to analyse plant distribution and trait data across Europe and find that plant height clustering is related to both evapotranspiration (ET) and gross primary productivity. This clustering is a signal of interspecies competition between plants, which is most evident in mid-latitude ecoregions, where conditions for growth (reflected in actual ET rates and gross primary productivities) are optimal. Away from this optimum, climate severity probably overrides the effect of competition, or other interactions become increasingly important. Our approach bridges the gap between species-rich competition theories and large-scale species distribution data analysis.
Scalability of resonant motor-driven flapping wing propulsion systems
Authors: Nabawy Mostafa R. A. , Marcinkeviciute Ruta
Published: September 2021

This work aims to develop an integrated conceptual design process to assess the scalability and performance of propulsion systems of resonant motor-driven flapping wing vehicles. The developed process allows designers to explore the interaction between electrical, mechanical and aerodynamic domains in a single transparent design environment. Wings are modelled based on a quasi-steady treatment that evaluates aerodynamics from geometry and kinematic information. System mechanics is modelled as a damped second-order dynamic system operating at resonance with nonlinear aerodynamic damping. Motors are modelled using standard equations that relate operational parameters and AC voltage input. Design scaling laws are developed using available data based on current levels of technology. The design method provides insights into the effects of changing core design variables such as the actuator size, actuator mass fraction and pitching kinematics on the overall design solution. It is shown that system efficiency achieves peak values of 30–36% at motor masses of 0.5–1 g when a constant angle of attack kinematics is employed. While sinusoidal angle of attack kinematics demands more aerodynamic and electric powers compared with the constant angle of attack case, sinusoidal angle of attack kinematics can lead to a maximum difference of around 15% in peak system efficiency.
Foraging efficiency in temporally predictable environments: is a long-term temporal memory really advantageous?
Authors: Robira Benjamin , Benhamou Simon , Masi Shelly , Llaurens Violaine , Riotte-Lambert Louise
Published: September 2021

Cognitive abilities enabling animals that feed on ephemeral but yearly renewable resources to inferwhenresources are available may have been favoured by natural selection, but the magnitude of the benefits brought by these abilities remains poorly known. Using computer simulations, we compared the efficiencies of three main types of foragers with different abilities to process temporal information, in spatially and/or temporally homogeneous or heterogeneous environments. One was endowed with asamplingmemory, which stores recent experience about the availability of the different food types. The other two were endowed with achronologicalorassociativememory, which stores long-term temporal information about absolute times of these availabilities or delays between them, respectively. To determine the range of possible efficiencies, we also simulated a forager without temporal cognition but which simply targeted the closest and possibly empty food sources, and a perfectly prescient forager, able to know at any time which food source was effectively providing food. Thesampling,associativeandchronologicalforagers were far more efficient than the forager without temporal cognition in temporally predictable environments, and interestingly, their efficiencies increased with the level of temporal heterogeneity. The use of a long-term temporal memory results in a foraging efficiency up to 1.16 times better (chronologicalmemory) or 1.14 times worse (associativememory) than the use of a simplesamplingmemory. Our results thus show that, for everyday foraging, a long-term temporal memory did not provide a clear benefit over a simple short-term memory that keeps track of the current resource availability. Long-term temporal memories may therefore have emerged in contexts where short-term temporal cognition is useless, i.e. when the anticipation of future environmental changes is strongly needed.
Maximizing average throughput in oscillatory biochemical synthesis systems: an optimal control approach
Authors: Ali Al-Radhawi M. , Margaliot Michael , Sontag Eduardo D.
Published: September 2021

A dynamical system
entrains
to a periodic input if its state converges globally to an attractor with the same period. In particular, for a constant input, the state converges to a unique equilibrium point for any initial condition. We consider the problem of maximizing a weighted average of the system’s output along the periodic attractor. The
gain of entrainment
is the benefit achieved by using a non-constant periodic input relative to a constant input with the same time average. Such a problem amounts to optimal allocation of resources in a periodic manner. We formulate this problem as a periodic optimal control problem, which can be analysed by means of the Pontryagin maximum principle or solved numerically via powerful software packages. We then apply our framework to a class of nonlinear occupancy models that appear frequently in biological synthesis systems and other applications. We show that, perhaps surprisingly, constant inputs are optimal for various architectures. This suggests that the presence of non-constant periodic signals, which frequently appear in biological occupancy systems, is a signature of an underlying
time-varying
objective functional being optimized.
Why is the literature on first impressions so focused on White faces?
Authors: Cook Richard , Over Harriet
Published: September 2021

We spontaneously attribute to strangers a wide variety of character traits based on their facial appearance. While these first impressions have little or no basis in reality, they exert a strong influence over our behaviour. Cognitive scientists have revealed a great deal about first impressions from faces including their factor structure, the cues on which they are based, the neurocognitive mechanisms responsible, and their developmental trajectory. In this field, authors frequently strive to remove as much ethnic variability from stimulus sets as possible. Typically, this convention means that participants are asked to judge the likely traits of White faces only. In the present article, we consider four possible reasons for the lack of facial diversity in this literature and find that it is unjustified. Next, we illustrate how the focus on White faces has undermined scientific efforts to understand first impressions from faces and argue that it reinforces socially regressive ideas about ‘race’ and status. We go on to articulate our concern that opportunities may be lost to leverage the knowledge derived from the study of first impressions against the dire consequences of prejudice and discrimination. Finally, we highlight some promising developments in the field.
We predict a riot: inequity, relative deprivation and collective destruction in the laboratory
Authors: Dezecache Guillaume , Allen James M. , von Zimmermann Jorina , Richardson Daniel C.
Published: September 2021

Riots are unpredictable and dangerous. Our understanding of the factors that cause riots is based on correlational observations of population data, orpost hocintrospection of individuals. To complement these accounts, we developed innovative experimental techniques, investigated the psychological factors of rioting and explored their consequences with agent-based simulations. We created a game, ‘Parklife’, that physically co-present participants played using smartphones. In two teams, participants tapped on their screen to grow trees and flowerbeds on separate but adjacent virtual parks. Participants could also tap to vandalize the other team's park. In some conditions, we surreptitiously introduced inequity between the teams so that one (the disadvantaged team) had to tap more for each reward. The experience of inequity caused the disadvantaged team to engage in more destruction, and to report higher relative deprivation and frustration. Agent-based models suggested that acts of destruction were driven by the interaction between individual level of frustration and the team's behaviour. Our results provide insights into the psychological mechanisms underlying collective action.
The demographic history of Madagascan micro-endemics: have rare species always been rare?
Authors: Helmstetter Andrew J. , Cable Stuart , Rakotonasolo Franck , Rabarijaona Romer , Rakotoarinivo Mijoro , Eiserhardt Wolf L. , Baker William J. , Papadopulos Alexander S. T.
Published: September 2021

Extinction has increased as human activities impact ecosystems, yet relatively few species have conservation assessments. Novel approaches are needed to highlight threatened species that are currently data-deficient. Many Madagascan plant species have extremely narrow ranges, but this may not have always been the case—it is unclear how the island's diverse flora evolved. To assess this, we generated restriction-site associated DNA sequence data for 10 Madagascan plant species, estimated effective population size (Ne) for each species and compared this to census (Nc) sizes. In each case,Newas an order of magnitude larger thanNc—signifying rapid, recent population decline. We then estimated species' demographic history, tracking changes inNeover time. We show that it is possible to predict extinction risk, particularly in the most threatened species. Furthermore, simulations showed that our approach has the power to detect population decline during the Anthropocene. Our analyses reveal that Madagascar's micro-endemics were not always rare, having experienced a rapid decline in their recent history. This casts further uncertainty over the processes that generated Madagascar's exceptional biodiversity. Our approach targets data-deficient species in need of conservation assessment, particularly in regions where human modification of the environment has been rapid.
The social shape of sperm: using an integrative machine-learning approach to examine sperm ultrastructure and collective motility
Authors: Hook Kristin A. , Yang Qixin , Campanello Leonard , Losert Wolfgang , Fisher Heidi S.
Published: September 2021

Sperm is one of the most morphologically diverse cell types in nature, yet they also exhibit remarkable behavioural variation, including the formation of collective groups of cells that swim together for motility or transport through the female reproductive tract. Here, we take advantage of natural variation in sperm traits observed acrossPeromyscusmice to test the hypothesis that the morphology of the sperm head influences their sperm aggregation behaviour. Using both manual and automated morphometric approaches to quantify their complex shapes, and then statistical modelling and machine learning to analyse their features, we show that the aspect ratio of the sperm head is the most distinguishing morphological trait and statistically associates with collective sperm movements obtained fromin vitroobservations. We then successfully use neural network analysis to predict the size of sperm aggregates from sperm head morphology and show that species with relatively wider sperm heads form larger aggregates, which is consistent with the theoretical prediction that an adhesive region around the equatorial region of the sperm head mediates these unique gametic interactions. Together these findings advance our understanding of how even subtle variation in sperm design can drive differences in sperm function and performance.
Transitions to asexuality and evolution of gene expression in
Artemia
brine shrimp
Authors: Huylmans Ann Kathrin , Macon Ariana , Hontoria Francisco , Vicoso Beatriz
Published: September 2021

While sexual reproduction is widespread among many taxa, asexual lineages have repeatedly evolved from sexual ancestors. Despite extensive research on the evolution of sex, it is still unclear whether this switch represents a major transition requiring major molecular reorganization, and how convergent the changes involved are. In this study, we investigated the phylogenetic relationship and patterns of gene expression of sexual and asexual lineages of Eurasian
Artemia
brine shrimp, to assess how gene expression patterns are affected by the transition to asexuality. We find only a few genes that are consistently associated with the evolution of asexuality, suggesting that this shift may not require an extensive overhauling of the meiotic machinery. While genes with sex-biased expression have high rates of expression divergence within Eurasian
Artemia
, neither female- nor male-biased genes appear to show unusual evolutionary patterns after sexuality is lost, contrary to theoretical expectations.
Cross-continental experimental infections reveal distinct defence mechanisms in populations of the three-spined stickleback
Gasterosteus aculeatus
Authors: Piecyk Agnes , Hahn Megan A. , Roth Olivia , Dheilly Nolwenn M. , Heins David C. , Bell Michael A. , Kalbe Martin
Published: September 2021

Epidemiological traits of host–parasite associations depend on the effects of the host, the parasite and their interaction. Parasites evolve mechanisms to infect and exploit their hosts, whereas hosts evolve mechanisms to prevent infection and limit detrimental effects. The reasons why and how these traits differ across populations still remain unclear. Using experimental cross-infection of three-spined stickleback
Gasterosteus aculeatus
and their species-specific cestode parasites
Schistocephalus solidus
from Alaskan and European populations, we disentangled host, parasite and interaction effects on epidemiological traits at different geographical scales. We hypothesized that host and parasite main effects would dominate both within and across continents, although interaction effects would show geographical variation of natural selection within and across continents. We found that mechanisms preventing infection (qualitative resistance) occurred only in a combination of hosts and parasites from different continents, while mechanisms limiting parasite burden (quantitative resistance) and reducing detrimental effects of infection (tolerance) were host-population specific. We conclude that evolution favours distinct defence mechanisms on different geographical scales and that it is important to distinguish concepts of qualitative resistance, quantitative resistance and tolerance in studies of macroparasite infections.
Rejection of the reclassification of Leuconostoc gasicomitatum as Leuconostoc gelidum subsp. gasicomitatum based on whole genome analysis
Authors: Wu Yan , Gu Chun Tao
Published: September 2021

In 2014, Rahkila et al. transferred

Leuconostoc gasicomitatum

to

Leuconostoc gelidum

as

L. gelidum

subsp.

gasicomitatum

comb. nov. based on a 75 % DNA–DNA hybridization value. In the present study, the taxonomic status of

L. gelidum

subsp.

gasicomitatum

is re-evaluated by a polyphasic approach, including 16S rRNA, pheS, rpoA, recA, and atpA gene sequence analyses, phylogenomic treeing, analyses of ANI (average nucleotide identity) and dDDH (digital DNA–DNA hybridization), fatty acid methyl ester analysis and a phenotypic characterization. On the basis of the ANI and dDDH values, we propose to reject the proposal of Rahkila et al. to reclassify

L. gasicomitatum

as

L. gelidum

subsp. gasicomitatum.
Age-specific effects of childhood Body Mass Index on multiple sclerosis risk
Authors: Hone Luke , Jacobs Benjamin M , Marshall Charles , Giovannoni Gavin , Noyce Alastair , Dobson Ruth
Published: September 2021

Objective

Higher Body Mass Index (BMI) during early life is thought to be a causal risk factor for Multiple Sclerosis (MS). We used longitudinal mendelian randomisation (MR) to determine whether there is a critical window during which BMI influences MS risk.

Methods

Summary statistics for childhood BMI and for MS susceptibility were obtained from recent large GWAS. We generated exposure instruments for BMI during four non-overlapping epochs (< 3 months, 3 months-1.5 years, 2-5 years, and 7-8 years) and performed MR using the inverse-variance weighted method with standard sensitivity analyses. Multivariable MR was used to account for effects mediated via later-life BMI.

Results

For all time epochs other than birth, genetically determined higher BMI was associated with an increased liability to MS: Birth (OR 0.81, 95% CI 0.50-1.31, NSNPs=7, p=0.39), Infancy (OR 1.18, 95%CI 1.04-1.33, NSNPs=18, p=0.01), Early childhood (OR 1.31, 95%CI 1.03-1.66, NSNPs=4, p=0.03), Later childhood (OR 1.34, 95% CI 1.08-1.66, NSNPs=4, p=0.01). Multivariable MR suggested that these effects may be mediated by effects on adult BMI.

Conclusion

We provide evidence using MR that genetically-determined higher BMI during early life is associated with increased MS risk. This effect may be driven by shared genetic architecture with later-life BMI.