bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmental factors driving arbuscular mycorrhizal fungal communities associated with endemic woody plant Picconiaazorica on native forest of Azores
Authors: Melo Catarina Drumonde , Walker Christopher , Krüger Claudia , Borges Paulo A.V. , Luna Sara , Mendonça Duarte , Fonseca Henrique M. A. C. , Machado Artur Câmara
Published: December 2019

Purpose

Arbuscular mycorrhizal fungi (AMF) play important key roles in the soil ecosystems as they link plants to the root-inaccessible part of soil. The aims of this study were to investigate which environmental factors influence the spatial and temporal structuring of AMF communities associated toPicconia azoricain two Azorean islands (Terceira and São Miguel islands), and investigate the seasonal variation in AMF communities between the two islands.

Methods

Communities of AMF associated withP. azoricain native forest of two Azorean islands (Terceira and São Miguel) were characterised by spore morphology or molecular analysis.

Results

Forty-five AMF spore morphotypes were detected from the four fragments ofP. azoricaforest representing nine families of AMF.Acaulosporaceae(14) andGlomeraceae(9) were the most abundant families. AMF density and root colonisation varied significantly between islands and sampling sites. Root colonisation and spore density exhibited temporal patterns, which peaked in spring and were higher in Terceira than in São Miguel. The relative contribution of environmental factors showed that factors such as elevation, relative air humidity, soil pH, and soil available P, K, and Mg influenced AMF spore production and root colonisation.

Conclusion

Different sporulation patterns exhibited by the members of the commonest families suggested different life strategies. Adaptation to a particular climatic and soil condition and host phenology may explain seasonal differences in sporulation patterns. Cohorts of AMF associated toP. azoricaare shaped by regional processes including environmental filters such as soil properties and natural disturbance.
Size of the lower carnassial in the arctic and the red fox from Late Pleistocene in Belgium compared to other ancient and extant populations
Authors: Szuma Elwira , Germonpré Mietje
Published: December 2019

Lengths, widths, and size proportions (length to width) of the lower carnassial were measured in 45 teeth of the arctic fox and 35 teeth of the red fox from Belgium radiocarbon dated to 46 640–14 120 ka BP. Data the Late Pleistocene foxes from Belgium were compared to 20 ancient and extant populations form Europe, Asia, and North America. The Pleistocene arctic fox from Belgium showed larger carnassial than in all recent samples of this species, whereas the Belgian fossil red foxes were characterized by the carnassial size comparable to that of the recent Siberian red foxes. Both fox species from the Pleistocene of Belgium showed the highest index of the carnassials length to width, which means increase in carnivorous adaptation. We conclude that the higher level of carnivorous specialization reached by the Belgian arctic and red foxes at the end of the Late Pleistocene reflected their scavenging on kills of large carnivores and human hunters (remains of megafauna). Harsh environmental conditions of that period and specific composition of ecosystems led to adapting to a more carnivorous food niche in both foxes.
Ba substitution for enhancement of the thermoelectric properties of LaCoO3 ceramics (0⩽x⩽0.75)
Authors: Bousnina Mohamed Ali , Giovannelli Fabien , Perriere Loïc , Guegan Guillaume , Delorme Fabian
Published: December 2019

In the present work, dense perovskite ceramics were successfully prepared from a series of La1–xBaxCoO3 solid solutions in the range of substitution 0 ⩽ x ⩽ 0.75 using solid state reaction and conventional sintering. Structural properties of La1–xBaxCoO3 were systematically investigated and thermoelectric properties were measured in the temperature range of 330–1000 K. The results show that the thermoelectric properties of Ba-substituted LaCoO3 depend on x. Indeed, at 330 K, electrical conductivity presents an optimum value for x = 0.25 with a value of σmax ≈ 2.2×105 S·m−1 whereas the Seebeck coefficient decreases when x and/or the temperature increases. The Ba-substituted LaCoO3 samples exhibit p-type semiconducting behaviour. The best power factor value found is 3.4×10−4 W·m−1·K−2 at 330 K for x = 0.075, which is 10% higher than the optimum value measured in La1–xSrxCoO3 for x = 0.05. The thermal diffusivity and thermal conductivity increase with increasing temperature and Ba concentration. La1–xBaxCoO3 shows a maximum figure of merit (ZT = 0.048) for x = 0.05 at 330 K, 25% higher than the best value in La1−xSrxCoO3 compounds.
A Theoretical Framework for the Evaluation of Massive Digital Participation Systems in Urban Planning
Authors: Hofmann Mathias , Münster Sander , Noennig Jörg Rainer
Published: December 2019

Urban development that strives to meet democratic ideals and the needs of all stakeholders must incorporate public participation. Contemporary participation processes may employ digital tools that open new possibilities regarding the range of participants and the intensity of participation. In particular, they can uniquely allow for large and diverse groups of participants to be involved in collaborative design processes. Evaluating such processes is important because it allows for the justification of the necessary costs and efforts, as well as continuous improvement. Using the phases specified in the minimal viable process of the U_CODE project as an example, this paper aims at describing criteria for the evaluation of participation processes and propose several possible methods for their assessment. While the majority of these criteria resemble criteria traditionally used to assess public participation in general, this paper proposes an additional criterion, as well as ways of applying all of the criteria to digital participation methods. In addition, the criteria and methods described in this paper not only may be used for evaluative purposes during or after a digital participation process but may also be useful guidelines during the planning stages of participation processes. Hence, it may help to consider these criteria to assess the value of the process during its inception stage to avoid mistakes and to enhance the democratic value of the participation process.
Learners’ continuance participation intention of collaborative group project in virtual learning environment: an extended TAM perspective
Authors: Li Honglei , Yu Jiuhong
Published: December 2019

The aim of this study is to explore learners’ intention to return to the electronic environment through the use of wikipages. The survey is based on students’ participation in a collaborative group project over a one semester course on business information systems. A research model based on the extended Technology Acceptance Model (TAM) has been proposed to investigate what factors will influence learners’ continuance participation in the electronic learning environment. 75% of students returned the questionnaire and the data analysis results based on the extended TAM Shows that the learners’ intention to return to the electronic learning environment was highly associated with their attitude towards the electronic learning tool and the affection associated with the tool.
Schooling while incarcerated as a turning point for serious juvenile and young adult offenders
Authors: Jäggi Lena , Kliewer Wendy , Serpell Zewelanji
Published: December 2019

Introduction

Attending school and working are consistently associated with positive outcomes for juvenile offenders returning to the community.

Methods

Using longitudinal data from the Pathways to Desistance Study, we used structural equation modeling to test whether better school experiences while incarcerated was positively connected to adjustment upon release among serious juvenile offenders (91% male) in the U.S. Adjustment was assessed as attending school for 310 legal minors (<18 years), and engaging in work for 259 emerging adults (≥18 years), as well as self‐reported delinquency for all participants.

Results

Accounting for incarceration and school history, results showed that facility school attachment, but not grades, was associated with decreased delinquency 12 months after release across sex in both age groups. Additionally, facility school attachment predicted engagement in school for returning minors. However, facility school experience was not related to engaging in work for returning emerging adults.

Conclusions

Results indicate that facility school climate matters for all juvenile offenders returning to their communities and that correctional education done right presents an important opportunity to reconnect returning minors with school, an important normative context of development. Conversely, results suggest that returning offenders who have ‘aged out’ of high school are a separate vulnerable group who may need additional support for successful reentry.
PsyMuKB: An Integrative De Novo Variant Knowledge Base for Developmental Disorders
Authors: Lin Guan Ning , Guo Sijia , Tan Xian , Wang Weidi , Qian Wei , Song Weichen , Wang Jingru , Yu Shunying , Wang Zhen , Cui Donghong , Wang Han
Published: December 2019

De novo variants (DNVs) are one of the most significant contributors to severe early-onset genetic disorders such as autism spectrum disorder, intellectual disability, and other developmental and neuropsychiatric (DNP) disorders. Presently, a plethora of DNVs have been identified using next-generation sequencing, and many efforts have been made to understand their impact at the gene level. However, there has been little exploration of the effects at the isoform level. The brain contains a high level of alternative splicing and regulation, and exhibits a more divergent splicing program than other tissues. Therefore, it is crucial to explore variants at the transcriptional regulation level to better interpret the mechanisms underlying DNP disorders. To facilitate a better usage and improve the isoform-level interpretation of variants, we developed NeuroPsychiatric Mutation Knowledge Base (PsyMuKB). It contains a comprehensive, carefully curated list of DNVs with transcriptional and translational annotations to enable identification of isoform-specific mutations. PsyMuKB allows a flexible search of genes or variants and provides both table-based descriptions and associated visualizations, such as expression, transcript genomic structures, protein interactions, and the mutation sites mapped on the protein structures. It also provides an easy-to-use web interface, allowing users to rapidly visualize the locations and characteristics of mutations and the expression patterns of the impacted genes and isoforms. PsyMuKB thus constitutes a valuable resource for identifying tissue-specific DNVs for further functional studies of related disorders. PsyMuKB is freely accessible at http://psymukb.net.
Ecological Models
Authors: Odenbaugh Jay
Published: December 2019

In this book, we consider three questions. What are ecological models? How are they tested? How do ecological models inform environmental policy and politics? Through several case studies, we see how these representations which idealize and abstract can be used to explain and predict complicated ecological systems. Additionally, we see how they bear on environmental policy and politics.
Rural versus Urban Areas and the Supplemental Nutrition Assistance Program
Authors: Weerasooriya Senal A. , Reimer Jeffrey J.
Published: December 2019

This study quantifies how spending changes induced by the Supplemental Nutrition Assistance Program (SNAP) affects production and employment in rural and urban areas. A general equilibrium simulation model with an estimated demand system is first used to project how SNAP affects spending on different goods and services. These impacts are then linked to the expansion and contraction of different economic sectors that differ in importance across rural and urban Oregon. In urban areas, a number of service sectors linked to higher-income households shrink slightly in response to SNAP, while food-related sectors expand; the net effect on jobs is slightly negative. Production changes in rural areas are generally smaller, while having a slightly positive net effect on jobs. Overall, SNAP makes a positive difference for low- or no-income households without strong effects elsewhere in the economy.
The Chronology of Medieval Copenhagen
Authors: Olsen Jesper , Dahlström Hanna , Poulsen Bjørn
Published: December 2019

Historical sources reveals that Copenhagen was founded in the late 12th century AD by Bishop Absalon. However, during the excavation for the new metro in central Copenhagen a previously unknown early medieval cemetery was discovered and excavated at the Town Hall Square. Radiocarbon (14C) analysis was conducted on the 9 individuals found in situ, together with 11 individuals from the other early medieval cemetery in Copenhagen, belonging to the St Clemens church. The radiocarbon analysis places the onset of the cemeteries to the early 11th century AD and therefore questions the age of Copenhagen and hence the archaeological and historical perception of the Danish historical record. Here a detailed account of the radiocarbon-based Bayesian model is presented.
Understanding price incentives to upsize combination meals at large US fast-food restaurants
Authors: Vercammen Kelsey A , Frelier Johannah M , Moran Alyssa J , Dunn Caroline G , Musicus Aviva A , Wolfson Julia , Ullah Omar S , Bleich Sara N
Published: December 2019

Objective:

To understand price incentives to upsize combination meals at fast-food restaurants by comparing the calories (i.e. kilocalories; 1 kcal = 4·184 kJ) per dollar of default combination meals (as advertised on the menu) with a higher-calorie version (created using realistic consumer additions and portion-size changes).

Design:

Combination meals (lunch/dinner:n258, breakfast:n68, children’s:n34) and their prices were identified from online menus; corresponding nutrition information for each menu item was obtained from a restaurant nutrition database (MenuStat). Linear models were used to examine the difference in total calories per dollar between default and higher-calorie combination meals, overall and by restaurant.

Setting:

Ten large fast-food chain restaurants located in the fifteen most populous US cities in 2017–2018.

Participants:

None.

Results:

There were significantly more calories per dollar in higher-caloriev.default combination meals for lunch/dinner (default: 577 kJ (138 kcal)/dollar, higher-calorie: 707 kJ (169 kcal)/dollar, difference: 130 kJ (31 kcal)/dollar,P< 0·001) and breakfast (default: 536 kJ (128 kcal)/dollar, higher-calorie: 607 kJ (145 kcal)/dollar, difference: 71 kJ (17 kcal)/dollar,P= 0·009). Results for children’s meals were in the same direction but were not statistically significant (default: 536 kJ (128 kcal)/dollar, higher-calorie: 741 kJ (177 kcal)/dollar, difference: 205 kJ (49 kcal)/dollar,P= 0·053). Across restaurants, the percentage change in calories per dollar for higher-caloriev. default combination meals ranged from 0·1 % (Dunkin’ Donuts) to 55·0 % (Subway).

Conclusions:

Higher-calorie combination meals in fast-food restaurants offer significantly more calories per dollar compared with default combination meals, suggesting there is a strong financial incentive for consumers to ‘upsize’ their orders. Future research should test price incentives for lower-calorie options to promote healthier restaurant choices.
An investigation into the effects of vocabulary learning strategies on the retention of Latin vocabulary in a Year 7 class
Authors: Warwicker Hannah
Published: December 2019

This study took place in a Year 7 class in a selective mixed independent school and examines the use of learning strategies for Latin vocabulary. The students were asked how they normally learn vocabulary, and these results using their normal method are compared to the results of using three different strategies.
Promoting Racial Diversity in Geoscience Through Transparency
Authors: Dutt Kuheli
Published: December 2019

Geoscience is notoriously lacking in diversity. Institutions can change this by making recruitment and selection processes transparent and by actively engaging minority students.
Rapid Loss of CO2 From the South Pacific Ocean During the Last Glacial Termination
Authors: Allen Katherine A. , Sikes Elisabeth L. , Anderson Robert F. , Rosenthal Yair
Published: December 2019

During the termination of the last ice age, atmospheric CO2 rose ~80 ppm, but the origin of this carbon has not been fully resolved. Here we present novel constraints on the patterns and processes of deglacial CO2 release using three marine sediment cores from the southwest Pacific. Carbon isotopes (δ13C) and boron to calcium ratios (B/Ca) of benthic foraminiferal calcite provide records of the δ13C of total dissolved inorganic carbon (DIC) and carbonate ion concentrations ([CO32−]) in seawater, respectively. Together these properties indicate enhanced storage of respired CO2 between 1.2‐ and 2.5‐km water depth during the Last Glacial Maximum (19–23 thousand years ago, ka). The first major rise in atmospheric CO2 during the last deglaciation, at the time of Heinrich Stadial 1, was accompanied by increases in δ13C and [CO32−] at all core depths. The initial increases could be attributed to southward shifted westerly winds driving increased upwelling in the Southern Ocean, sending a signal of enhanced ventilation northward into the Pacific. Our results confirm that southern Pacific interior water masses served as an important reservoir for CO2 during the last glacial period, likely extracted from the atmosphere via the biologic pump. Some abrupt changes in Pacific carbon storage coincide with changes in Southern Ocean pH (Rae et al., 2018, https://doi.org/10.1038/s41586‐018‐0614‐0), upwelling indicators (Anderson et al., 2009, https://doi.org/10.1126/science.1167441), and pCO2 (Monnin et al., 2001, https://doi.org/10.1126/science.291.5501.112), indicating that portions of the deep Pacific carbon pool can be ventilated rapidly to the atmosphere via the Southern Ocean.
Freezing Temperature Controls Winter Water Discharge for Cold Region Watershed
Authors: Wang Shusen
Published: December 2019

Pronounced climate warming over the arctic‐subarctic regions has lead to profound hydrological changes including intensified river flow, but how soil frost controls aquifer discharge remains poorly understood. This study quantifies the relationship between freezing temperature and baseflow in winter. Analyses show that the traditional reservoir models are unable to reproduce the observed baseflow variations. By incorporating a freezing temperature function in the reservoir models, the model performances are largely improved. It indicates the dominant role of freezing temperature in controlling the aquifer discharge through reducing the watershed conductivity and liquid (active) water content. The results for the Albany watershed in Canada show that the watershed lump conductivity decreases by half when air temperature accumulates to −172 °C·day from winter start and in extremely cold years, it could decrease by more than 85%. With this relationship, a climate warming of +1, +2, and +4 °C would suggest an increase of 7.7%, 16.7%, and 41.0% in conductivity or 6.8%, 14.7%, and 35.0% in winter discharge, respectively. The study provides an important link between climate warming and aquifer discharge in cold regions. The results could be particularly useful for developing process‐based models, estimating baseflow variations, and assessing climate change impact on cold region hydrology.
The neural and molecular basis of working memory function in psychosis: a multimodal PET-fMRI study
Authors: Borgan Faith , O’Daly Owen , Veronese Mattia , Reis Marques Tiago , Laurikainen Heikki , Hietala Jarmo , Howes Oliver
Published: December 2019

Working memory (WM) deficits predict clinical and functional outcomes in schizophrenia but are poorly understood and unaddressed by existing treatments. WM encoding and WM retrieval have not been investigated in schizophrenia without the confounds of illness chronicity or the use of antipsychotics and illicit substances. Moreover, it is unclear if WM deficits may be linked to cannabinoid 1 receptor dysfunction in schizophrenia. Sixty-six volunteers (35 controls, 31 drug-free patients with diagnoses of schizophrenia or schizoaffective disorder) completed the Sternberg Item-Recognition paradigm during an fMRI scan. Neural activation during WM encoding and WM retrieval was indexed using the blood-oxygen-level-dependent hemodynamic response. A subset of volunteers (20 controls, 20 drug-free patients) underwent a dynamic PET scan to measure [11C] MePPEP distribution volume (ml/cm3) to index CB1R availability. In a whole-brain analysis, there was a significant main effect of group on task-related BOLD responses in the superior parietal lobule during WM encoding, and the bilateral hippocampus during WM retrieval. Region of interest analyses in volunteers who had PET/fMRI indicated that there was a significant main effect of group on task-related BOLD responses in the right hippocampus, left DLPFC, left ACC during encoding; and in the bilateral hippocampus, striatum, ACC and right DLPFC during retrieval. Striatal CB1R availability was positively associated with mean striatal activation during WM retrieval in male patients (R = 0.5, p = 0.02) but not male controls (R = −0.20, p = 0.53), and this was significantly different between groups, Z = −2.20, p = 0.02. Striatal CB1R may contribute to the pathophysiology of WM deficits in male patients and have implications for drug development in schizophrenia.
Cellular calcium in bipolar disorder: systematic review and meta-analysis
Authors: Harrison Paul J. , Hall Nicola , Mould Arne , Al-Juffali Noura , Tunbridge Elizabeth M.
Published: December 2019

Calcium signalling has long been implicated in bipolar disorder, especially by reports of altered intracellular calcium ion concentrations ([Ca2+]). However, the evidence has not been appraised critically. We carried out a systematic review and meta-analysis of studies of cellular calcium indices in bipolar disorder. 2281 records were identified and 117 screened, of which 32 were eligible and 21 were suitable for meta-analyses. The latter each involved up to 642 patients and 404 control subjects. We found that basal free intracellular [Ca2+] is increased in bipolar disorder, both in platelets and in lymphocytes. The effect size is 0.55, with an estimated elevation of 29%. It is observed in medication-free patients. It is present in mania and bipolar depression, but data are equivocal for euthymia. Cells from bipolar disorder individuals also show an enhanced [Ca2+] response to stimulation with 5-HT or thrombin, by an estimated 25%, with an effect size of 0.63. In studies which included other diagnoses, intracellular basal [Ca2+] was higher in bipolar disorder than in unipolar depression, but not significantly different from schizophrenia. Functional parameters of cellular Ca2+ (e.g. calcium transients), and neuronal [Ca2+], have been much less investigated, and no firm conclusions can be drawn. In summary, there is a robust, medium effect size elevation of basal and stimulated free intracellular [Ca2+] in bipolar disorder. The results suggest altered calcium functioning in the disorder, and encourage further investigations into the underlying mechanisms, and the implications for pathophysiology and therapeutics.
Novel genome-wide associations for anhedonia, genetic correlation with psychiatric disorders, and polygenic association with brain structure
Authors: Ward Joey , Lyall Laura M. , Bethlehem Richard A. I. , Ferguson Amy , Strawbridge Rona J. , Lyall Donald M. , Cullen Breda , Graham Nicholas , Johnston Keira J. A. , Bailey Mark E. S. , Murray Graham K. , Smith Daniel J.
Published: December 2019

Anhedonia is a core symptom of several psychiatric disorders but its biological underpinnings are poorly understood. We performed a genome-wide association study of state anhedonia in 375,275 UK Biobank participants and assessed for genetic correlation between anhedonia and neuropsychiatric conditions (major depressive disorder, schizophrenia, bipolar disorder, obsessive compulsive disorder and Parkinson’s Disease). We then used a polygenic risk score approach to test for association between genetic loading for anhedonia and both brain structure and brain function. This included: magnetic resonance imaging (MRI) assessments of total grey matter volume, white matter volume, cerebrospinal fluid volume, and 15 cortical/subcortical regions of interest; diffusion tensor imaging (DTI) measures of white matter tract integrity; and functional MRI activity during an emotion processing task. We identified 11 novel loci associated at genome-wide significance with anhedonia, with a SNP heritability estimate (h2SNP) of 5.6%. Strong positive genetic correlations were found between anhedonia and major depressive disorder, schizophrenia and bipolar disorder; but not with obsessive compulsive disorder or Parkinson’s Disease. Polygenic risk for anhedonia was associated with poorer brain white matter integrity, smaller total grey matter volume, and smaller volumes of brain regions linked to reward and pleasure processing, including orbito-frontal cortex. In summary, the identification of novel anhedonia-associated loci substantially expands our current understanding of the biological basis of state anhedonia and genetic correlations with several psychiatric disorders confirm the utility of this phenotype as a transdiagnostic marker of vulnerability to mental illness. We also provide the first evidence that genetic risk for state anhedonia influences brain structure, including in regions associated with reward and pleasure processing.
Dietary sodium modulates nephropathy in Nedd4-2-deficient mice
Authors: Manning Jantina A. , Shah Sonia S. , Henshall Tanya L. , Nikolic Andrej , Finnie John , Kumar Sharad
Published: December 2019

Salt homeostasis is maintained by tight control of Na+ filtration and reabsorption. In the distal part of the nephron the ubiquitin protein ligase Nedd4-2 regulates membrane abundance and thus activity of the epithelial Na+ channel (ENaC), which is rate-limiting for Na+ reabsorption. Nedd4-2 deficiency in mouse results in elevated ENaC and nephropathy, however the contribution of dietary salt to this has not been characterized. In this study we show that high dietary Na+ exacerbated kidney injury in Nedd4-2-deficient mice, significantly perturbing normal postnatal nephrogenesis and resulting in multifocal areas of renal dysplasia, increased markers of kidney injury and a decline in renal function. In control mice, high dietary Na+ resulted in reduced levels of ENaC. However, Nedd4-2-deficient kidneys maintained elevated ENaC even after high dietary Na+, suggesting that the inability to efficiently downregulate ENaC is responsible for the salt-sensitivity of disease. Importantly, low dietary Na+ significantly ameliorated nephropathy in Nedd4-2-deficient mice. Our results demonstrate that due to dysregulation of ENaC, kidney injury in Nedd4-2-deficient mice is sensitive to dietary Na+, which may have implications in the management of disease in patients with kidney disease.
Characterization of the role of TMEM45A in cancer cell sensitivity to cisplatin
Authors: Schmit Kathleen , Chen Jia-Wei , Ayama-Canden Sophie , Fransolet Maude , Finet Laure , Demazy Catherine , D’Hondt Lionel , Graux Carlos , Michiels Carine
Published: December 2019

TMEM45A is a transmembrane protein involved in tumor progression and cancer resistance to chemotherapeutic agents in hypoxic condition. It is correlated to a low breast cancer patient overall survival. However, little is known about this protein, in particular the mechanisms by which TMEM45A modulates cancer cell chemosensitivity. In this work, the messenger RNA expression of TMEM45A was assessed in head and neck squamous cell carcinoma (HNSCC) and renal cell carcinoma (RCC) biopsies. TMEM45A was upregulated in patients diagnosed for head and neck or renal cancer. Then, the implication of this protein in cisplatin sensitivity was explored in SQD9 and RCC4 + pVHL cells. TMEM45A inactivation decreased cell proliferation and modulated cell responses to cisplatin. Indeed, TMEM45A inactivation increased the sensitivity of SQD9 cells to cisplatin, whereas it rendered RCC4 + pVHL cells resistant to this anticancer agent. Through RNA-sequencing analysis, we identified several deregulated pathways that indicated that the impact on cisplatin sensitivity may be associated to the inhibition of DNA damage repair and to UPR pathway activation. This study demonstrated, for the first time, an anti or a pro-apoptotic role of this protein depending on the cancer type and highlighted the role of TMEM45A in modulating patient responses to treatment.
Approaching diamond’s theoretical elasticity and strength limits
Authors: Nie Anmin , Bu Yeqiang , Li Penghui , Zhang Yizhi , Jin Tianye , Liu Jiabin , Su Zhang , Wang Yanbin , He Julong , Liu Zhongyuan , Wang Hongtao , Tian Yongjun , Yang Wei
Published: December 2019

Diamond is the hardest natural material, but its practical strength is low and its elastic deformability extremely limited. While recent experiments have demonstrated that diamond nanoneedles can sustain exceptionally large elastic tensile strains with high tensile strengths, the size- and orientation-dependence of these properties remains unknown. Here we report maximum achievable tensile strain and strength of diamond nanoneedles with various diameters, oriented in <100>, <110> and <111> -directions, using in situ transmission electron microscopy. We show that reversible elastic deformation depends both on nanoneedle diameter and orientation. <100> -oriented nanoneedles with a diameter of 60 nm exhibit highest elastic tensile strain (13.4%) and tensile strength (125 GPa). These values are comparable with the theoretical elasticity and Griffith strength limits of diamond, respectively. Our experimental data, together with first principles simulations, indicate that maximum achievable elastic strain and strength are primarily determined by surface conditions of the nanoneedles.
Photo-activated raster scanning thermal imaging at sub-diffraction resolution
Authors: Bouzin M. , Marini M. , Zeynali A. , Borzenkov M. , Sironi L. , D’Alfonso L. , Mingozzi F. , Granucci F. , Pallavicini P. , Chirico G. , Collini M.
Published: December 2019

Active thermal imaging is a valuable tool for the nondestructive characterization of the morphological properties and the functional state of biological tissues and synthetic materials. However, state-of-the-art techniques do not typically combine the required high spatial resolution over extended fields of view with the quantification of temperature variations. Here, we demonstrate quantitative far-infrared photo-thermal imaging at sub-diffraction resolution over millimeter-sized fields of view. Our approach combines the sample absorption of modulated raster-scanned laser light with the automated localization of the laser-induced temperature variations imaged by a thermal camera. With temperature increments ∼0.5–5 °C, we achieve a six-time gain with respect to our 350-μm diffraction-limited resolution with proof-of-principle experiments on synthetic samples. We finally demonstrate the biological relevance of sub-diffraction thermal imaging by retrieving temperature-based super-resolution maps of the distribution of Prussian blue nanocubes across explanted murine skin biopsies.
Ultralow lattice thermal conductivity of chalcogenide perovskite CaZrSe3 contributes to high thermoelectric figure of merit
Authors: Osei-Agyemang Eric , Adu Challen Enninful , Balasubramanian Ganesh
Published: December 2019

An emerging chalcogenide perovskite, CaZrSe3, holds promise for energy conversion applications given its notable optical and electrical properties. However, knowledge of its thermal properties is extremely important, e.g. for potential thermoelectric applications, and has not been previously reported in detail. In this work, we examine and explain the lattice thermal transport mechanisms in CaZrSe3 using density functional theory and Boltzmann transport calculations. We find the mean relaxation time to be extremely short corroborating an enhanced phonon–phonon scattering that annihilates phonon modes, and lowers thermal conductivity. In addition, strong anharmonicity in the perovskite crystal represented by the Grüneisen parameter predictions, and low phonon number density for the acoustic modes, results in the lattice thermal conductivity to be limited to 1.17 W m−1 K−1. The average phonon mean free path in the bulk CaZrSe3 sample (N → ∞) is 138.1 nm and nanostructuring CaZrSe3 sample to ~10 nm diminishes the thermal conductivity to 0.23 W m−1 K−1. We also find that p-type doping yields higher predictions of thermoelectric figure of merit than n-type doping, and values of ZT ~0.95–1 are found for hole concentrations in the range 1016–1017 cm−3 and temperature between 600 and 700 K.
Bridging the gap between military prolonged field care monitoring and exploration spaceflight: the compensatory reserve
Authors: Schlotman Taylor E. , Lehnhardt Kris R. , Abercromby Andrew F. , Easter Benjamin D. , Downs Meghan E. , Akers L. T. C. Kevin S. , Convertino Victor A.
Published: December 2019

The concept of prolonged field care (PFC), or medical care applied beyond doctrinal planning timelines, is the top priority capability gap across the US Army. PFC is the idea that combat medics must be prepared to provide medical care to serious casualties in the field without the support of robust medical infrastructure or resources in the event of delayed medical evacuation. With limited resources, significant distances to travel before definitive care, and an inability to evacuate in a timely fashion, medical care during exploration spaceflight constitutes the ultimate example PFC. One of the main capability gaps for PFC in both military and spaceflight settings is the need for technologies for individualized monitoring of a patient’s physiological status. A monitoring capability known as the compensatory reserve measurement (CRM) meets such a requirement. CRM is a small, portable, wearable technology that uses a machine learning and feature extraction-based algorithm to assess real-time changes in hundreds of specific features of arterial waveforms. Future development and advancement of CRM still faces engineering challenges to develop ruggedized wearable sensors that can measure waveforms for determining CRM from multiple sites on the body and account for less than optimal conditions (sweat, water, dirt, blood, movement, etc.). We show here the utility of a military wearable technology, CRM, which can be translated to space exploration.
A mechanistic investigation of corrosion-driven organic coating failure on magnesium and its alloys
Authors: Williams Geraint , Kousis Christos , McMurray Neil , Keil Patrick
Published: December 2019

The failure mechanism of model organic coatings from Mg alloy surfaces is characterised by a combination in-situ scanning Kelvin probe analysis and time lapse photography. Initiation of underfilm corrosion by application of group I chloride salts to a penetrative coating defect produces an apparent cathodic-driven coating delamination, where the disbondment distance increases linearly with time at high relative humidity, although filiform corrosion (FFC) is also observed in the vicinity of the defect. The disbondment process occurs both in the presence and absence of oxygen, indicating that hydrogen evolution comprises the predominant underfilm cathodic reaction. Post-corrosion elemental analysis of the delaminated region shows an abundance of group I cation, but no chloride. When magnesium chloride or HCl are used to initiate corrosion, then only FFC is produced. The mechanism is discussed in terms of net anodic dissolution at the defect coupled with underfilm cathodic hydrogen evolution, producing organic coating disbondment under conditions where cations are able to transport ionic current within a zone of increased pH.
Mitochondrial DNA content and oxidation in bipolar disorder and its role across brain regions
Authors: Bodenstein D. F. , Kim H. K. , Brown N. C. , Navaid B. , Young L. T. , Andreazza A. C.
Published: December 2019

The underlying pathology of bipolar disorder remains unknown, though evidence is accumulating to support a role of mitochondrial dysfunction. In this study, we aim to investigate electron transport chain complex I subunit NDUFS7 protein expression; mtDNA content; common deletion; and oxidation in the Broadmann area 24 (BA24), cerebellum, hippocampus, and prefrontal cortex from patients with bipolar disorder, schizophrenia, and non-psychiatric controls. Here, we demonstrate no changes in NDUFS7 in BA24, cerebellum or hippocampus, increases in mtDNA content in hippocampus of patients with bipolar disorder, and decreases in mtDNA oxidation in patients with bipolar disorder and schizophrenia, respectively. Paired analysis between BA24 and cerebellum reveal increases within NDUFS7 levels and mtDNA content in cerebellum of patients with bipolar disorder or schizophrenia. We found a positive correlation between NDUFS7 and mtDNA content (ND4 and ND5) when combining brain regions. Our study supports the involvement of mitochondrial dysfunction in bipolar disorder and schizophrenia.
Rheological, physical, and mechanical properties of chicken skin gelatin films incorporated with potato starch
Authors: Alias Syazwani Aqilah , Mhd Sarbon Norizah
Published: December 2019

The aim of this study was to investigate the rheological, physical, and mechanical properties of chicken skin gelatin film forming solutions (FFSs) and films incorporated with potato starch. Chicken skin gelatin-based FFSs with various potato starch concentrations (0, 2, 4, 6, 8, and 10%, w/w) were prepared via casting technique. The dynamic viscoelastic properties of FFS were measured, and film characterization in terms of physical and mechanical properties was conducted. Potato starch incorporation with chicken skin gelatin-based FFS resulted in improvement of viscous behavior (G″ > G′). As potato starch concentration increased, the tensile strength, elongation at break, and elastic modulus values of chicken skin gelatin-based films also increased (p < 0.05). Additionally, increasing the concentration of potato starch caused incremental changes in water vapor permeability and melting temperatures (Tm), but a reduction in water solubility (p < 0.05). In addition, the surface smoothness and internal structure of composite films improved via potato starch incorporation. The incorporation of potato starch was also found to provide good barrier properties against ultraviolet and visible light, but did not significantly influence the transparency values of composite films. Overall, chicken skin gelatin film with 6% potato starch concentration incorporation was the most promising composite film, since it was found to exhibit optimal performance in terms of physical properties.
Nitric oxide modulating ion balance in Hylotelephium erythrostictum roots subjected to NaCl stress based on the analysis of transcriptome, fluorescence, and ion fluxes
Authors: Chen Zhixin , Zhao Xueqi , Hu Zenghui , Leng Pingsheng
Published: December 2019

Soil salinization is one of the main stress factors that affect both growth and development of plants. Hylotelephium erythrostictum exhibits strong resistance to salt, but the underlying genetic mechanisms remain unclear. In this study, hydroponically cultured seedlings of H. erythrostictum were exposed to 200 mM NaCl. RNA-Seq was used to determine root transcriptomes at 0, 5, and 10 days, and potential candidate genes with differential expression were analyzed. Transcriptome sequencing generated 89.413 Gb of raw data, which were assembled into 111,341 unigenes, 82,081 of which were annotated. Differentially expressed genes associated to Na+ and K+ transport, Ca2+ channel, calcium binding protein, and nitric oxide (NO) biosynthesis had high expression levels in response to salt stress. An increased fluorescence intensity of NO indicated that it played an important role in the regulation of the cytosolic K+/Na+ balance in response to salt stress. Exogenous NO donor and NO biosynthesis inhibitors significantly increased and decreased the Na+ efflux, respectively, thus causing the opposite effect for K+ efflux. Moreover, under salt stress, exogenous NO donors and NO biosynthesis inhibitors enhanced and reduced Ca2+ influx, respectively. Combined with Ca2+ reagent regulation of Na+ and K+ fluxes, this study identifies how NaCl-induced NO may function as a signaling messenger that modulates the K+/Na+ balance in the cytoplasm via the Ca2+ signaling pathway. This enhances the salt resistance in H. erythrostictum roots.
Pattern and Trend of Night Land Surface Temperature in Africa
Authors: Me-ead Cherdchai , McNeil Rhysa
Published: December 2019

This study aims to identify patterns and trends of the night land surface temperature over eight day period from 2000 to 2014 in Africa using statistical analysis. Data were obtained from the United States National Aeronautics and Space Administration satellite, comprising 99 locations of 5° by 5° latitude and longitude grid-boxes between latitudes 35° north and south of the equator and longitudes 20° west to 50° east. First, the variation in the night surface temperatures was removed. Then, the trend of seasonally adjusted night temperatures was estimated using linear regression. The correlations between adjoining regions were considered by using factor analysis to classify the temperatures into four regions. Cubic spline models were fitted to the data within these regions to investigate patterns of the temperatures. The result showed that temperatures in most regions of Africa increased. The temperatures decreased was observed in southern Africa and parts of central and eastern Africa.
First evidence of terrestrial ambrein formation in human adipocere
Authors: von der Lühe Barbara , Mayes Robert W. , Thiel Volker , Dawson Lorna A. , Graw Matthias , Rowland Steven J. , Fiedler Sabine
Published: December 2019

To date, the only known occurrence of ambrein, an important perfumery organic molecule, is in coproliths found in about one in a hundred sperm whales. Jetsam ambergris coproliths from the whale are also found occasionally on beaches worldwide. Here we report on the surprising occurrence of ambrein in human adipocere. Adipocere is a waxy substance formed post-mortem during incomplete anaerobic decomposition of soft tissues. Adipocere samples obtained from grave exhumations were analysed using gas chromatography-mass spectrometry (GC-MS). In addition to the typical fatty acids of adipocere, lesser amounts of ambrein were identified in the samples, in abundances similar to those of the major accompanying faecal steroids. The distribution of these compounds suggests that ambrein was produced post-mortem during the microbial decomposition of faecal residues and tissues. It is assumed that the adipocere matrix of saturated fatty acidsaided the preservation of ambrein over extended periods of time, because adipocere is stable against degradation. The association of ambrein formation in ageing faecal material, under moist, oxygen-depleted conditions, now requires more attention in studies of other mammalian and geological samples. Indeed, ambrein and its transformation products may be useful novel chemical indicators of aged faecal matter and decomposed bodies.
Use of numerical and spatial information in ordinal counting by zebrafish
Authors: Potrich Davide , Rugani Rosa , Sovrano Valeria Anna , Regolin Lucia , Vallortigara Giorgio
Published: December 2019

The use of non-symbolic numerical information is widespread throughout the animal kingdom, providing adaptive benefits in several ecological contexts. Here we provide the possible evidence of ordinal numerical skills in zebrafish (Danio rerio). Zebrafish were trained to identify the second exit in a series of five identically-spaced exits along a corridor. When at test the total length of the corridor (Exp. 1) or the distance between exits (Exp. 2) was changed, zebrafish appeared not to use the absolute spatial distance. However, zebrafish relied both on ordinal as well as spatial cues when the number of exits was increased (from 5 to 9) and the inter-exit distance was reduced (Exp. 3), suggesting that they also take into account relative spatial information. These results highlight that zebrafish may provide a useful model organism for the study of the genetic bases of non-symbolic numerical and spatial cognition, and of their interaction.
Integration of metabolome and transcriptome reveals flavonoid accumulation in the intergeneric hybrid between Brassica rapa and Raphanus sativus
Authors: Zhang Libin , Ma Chuang , Chao Hongbo , Long Yan , Wu Jiangsheng , Li Zaiyun , Ge Xianhong , Xia Heng , Yin Yongtai , Batley Jacqueline , Li Maoteng
Published: December 2019

Brassica rapa and Raphanus sativus are two important edible vegetables that contain numerous nutritional ingredients. However, the agronomic traits and nutritional components of the intergeneric hybrid of B. rapa and R. sativus remain poorly understood. In this study, we used a stably inherited intergeneric hybrid of B. rapa and R. sativus as a model to study its metabolome and transcriptome profiles. Morphological and cytological analysis showed the intergeneric hybrid had the expected chromosome number and normal meiosis behavior. Moreover, the metabolome analysis showed multiple important secondary metabolites, including flavonoids and glucosinolates, were significantly upregulated in the hybrid. Furthermore, transcriptome data revealed that the expression level of the important genes involved in phenylpropanoid and flavonoid pathways was significantly upregulated in the hybrid. Ultimately, our data indicate the intergeneric hybrid will be a valuable bioengineering resource and promise to become a new-type hybrid vegetable with great medicinal value in future.
A novel ER membrane protein Ehg1/May24 plays a critical role in maintaining multiple nutrient permeases in yeast under high-pressure perturbation
Authors: Kurosaka Goyu , Uemura Satoshi , Mochizuki Takahiro , Kozaki Yuri , Hozumi Akiko , Suwa Sayuri , Ishii Ryoga , Kato Yusuke , Imura Saki , Ishida Natsuho , Noda Yoichi , Abe Fumiyoshi
Published: December 2019

Previously, we isolated 84 deletion mutants in Saccharomyces cerevisiae auxotrophic background that exhibited hypersensitive growth under high hydrostatic pressure and/or low temperature. Here, we observed that 24 deletion mutants were rescued by the introduction of four plasmids (LEU2, HIS3, LYS2, and URA3) together to grow at 25 MPa, thereby suggesting close links between the genes and nutrient uptake. Most of the highly ranked genes were poorly characterized, including MAY24/YPR153W. May24 appeared to be localized in the endoplasmic reticulum (ER) membrane. Therefore, we designated this gene as EHG (ER-associated high-pressure growth gene) 1. Deletion of EHG1 led to reduced nutrient transport rates and decreases in the nutrient permease levels at 25 MPa. These results suggest that Ehg1 is required for the stability and functionality of the permeases under high pressure. Ehg1 physically interacted with nutrient permeases Hip1, Bap2, and Fur4; however, alanine substitutions for Pro17, Phe19, and Pro20, which were highly conserved among Ehg1 homologues in various yeast species, eliminated interactions with the permeases as well as the high-pressure growth ability. By functioning as a novel chaperone that facilitated coping with high-pressure-induced perturbations, Ehg1 could exert a stabilizing effect on nutrient permeases when they are present in the ER.