bluuebunny/crossref_metadata_2025 huggingface dataset:
Geographic Differences in Lung Transplant Volume and Donor Availability During the COVID-19 Pandemic
Authors: Benvenuto Luke , Snyder Mark E. , Aversa Meghan , Patel Shreena , Costa Joseph , Shah Lori , Robbins Hilary , D’Ovidio Frank , Sonett Joshua , Stanifer Bryan P. , Lemaitre Philippe , Arcasoy Selim , Anderson Michaela R.
Published: January 2021

Background.

Regional variation in lung transplantation practices due to local coronavirus disease 2019 (COVID-19) prevalence may cause geographic disparities in access to lung transplantation.

Methods.

Using the United Network for Organ Sharing registry, we conducted a descriptive analysis of lung transplant volume, donor lung volume, new waitlist activations, and waiting list deaths at high-volume lung transplant centers during the first 3 months of the pandemic (March 1. 2020, to May 30, 2020) and we compared it to the same period in the preceding 5 years.

Results.

Lung transplant volume decreased by 10% nationally and by a median of 50% in high COVID-19 prevalence centers (range –87% to 80%) compared with a median increase of 10% (range –87% to 80%) in low prevalence centers (P-for-trend 0.006). Donation services areas with high COVID-19 prevalence experienced a greater decrease in organ availability (-28% range, –72% to –11%) compared with low prevalence areas (+7%, range –20% to + 55%, P-for-trend 0.001). Waiting list activations decreased at 18 of 22 centers. Waiting list deaths were similar to the preceding 5 years and independent of local COVID-19 prevalence (P-for-trend 0.36).

Conclusions.

Regional variation in transplantation and donor availability in the early months of the pandemic varied by local COVID-19 activity.
A liar and a copycat: nonverbal coordination increases with lie difficulty
Authors: Van Der Zee Sophie , Taylor Paul , Wong Ruth , Dixon John , Menacere Tarek
Published: January 2021

Studies of the nonverbal correlates of deception tend to examine liars' behaviours as independent from the behaviour of the interviewer, ignoring joint action. To address this gap, experiment 1 examined the effect of telling a truth and easy, difficult and very difficult lies on nonverbal coordination. Nonverbal coordination was measured automatically by applying a dynamic time warping algorithm to motion-capture data. In experiment 2, interviewees also received instructions that influenced the attention they paid to either the nonverbal or verbal behaviour of the interviewer. Results from both experiments found that interviewer–interviewee nonverbal coordination increased with lie difficulty. This increase was not influenced by the degree to which interviewees paid attention to their nonverbal behaviour, nor by the degree of interviewer's suspicion. Our findings are consistent with the broader proposition that people rely on automated processes such as mimicry when under cognitive load.
Surrogate models based on machine learning methods for parameter estimation of left ventricular myocardium
Authors: Cai Li , Ren Lei , Wang Yongheng , Xie Wenxian , Zhu Guangyu , Gao Hao
Published: January 2021

A long-standing problem at the frontier of biomechanical studies is to develop fast methods capable of estimating material properties from clinical data. In this paper, we have studied three surrogate models based on machine learning (ML) methods for fast parameter estimation of left ventricular (LV) myocardium. We use three ML methods named K-nearest neighbour (KNN), XGBoost and multi-layer perceptron (MLP) to emulate the relationships between pressure and volume strains during the diastolic filling. Firstly, to train the surrogate models, a forward finite-element simulator of LV diastolic filling is used. Then the training data are projected in a low-dimensional parametrized space. Next, three ML models are trained to learn the relationships of pressure–volume and pressure–strain. Finally, an inverse parameter estimation problem is formulated by using those trained surrogate models. Our results show that the three ML models can learn the relationships of pressure–volume and pressure–strain very well, and the parameter inference using the surrogate models can be carried out in minutes. Estimated parameters from both the XGBoost and MLP models have much less uncertainties compared with the KNN model. Our results further suggest that the XGBoost model is better for predicting the LV diastolic dynamics and estimating passive parameters than other two surrogate models. Further studies are warranted to investigate how XGBoost can be used for emulating cardiac pump function in a multi-physics and multi-scale framework.
The interplay of blood flow and temperature in regional hyperthermia: a mathematical approach
Authors: Bosque Jesús J. , Calvo Gabriel F. , Pérez-García Víctor M. , Navarro María Cruz
Published: January 2021

In recent decades, hyperthermia has been used to raise oxygenation levels in tumours undergoing other therapeutic modalities, of which radiotherapy is the most prominent one. It has been hypothesized that oxygenation increases would come from improved blood flow associated with vasodilation. However, no test has determined whether this is a relevant assumption or other mechanisms might be acting. Additionally, since hyperthermia and radiotherapy are not usually co-administered, the crucial question arises as to how temperature and perfusion in tumours will change during and after hyperthermia. Overall, it would seem necessary to find a research framework that clarifies the current knowledge, delimits the scope of the different effects and guides future research. Here, we propose a simple mathematical model to account for temperature and perfusion dynamics in brain tumours subjected to regional hyperthermia. Our results indicate that tumours in well-perfused organs like the brain might only reach therapeutic temperatures if their vasculature is highly disrupted. Furthermore, the characteristic times of return to normal temperature levels are markedly shorter than those required to deliver adjuvant radiotherapy. According to this, a mechanistic coupling of perfusion and temperature would not explain any major oxygenation boost in brain tumours immediately after hyperthermia.
Bone need not remain an elephant in the room for radiocarbon dating
Authors: Herrando-Pérez Salvador
Published: January 2021

Radiocarbon (
14
C) analysis of skeletal remains by accelerator mass spectrometry is an essential tool in multiple branches of science. However, bone
14
C dating results can be inconsistent and not comparable due to disparate laboratory pretreatment protocols that remove contamination. And, pretreatments are rarely discussed or reported by end-users, making it an ‘elephant in the room’ for Quaternary scientists. Through a questionnaire survey, I quantified consensus on the reliability of collagen pretreatments for
14
C dating across 132 experts (25 countries). I discovered that while more than 95% of the audience was wary of contamination and would avoid gelatinization alone (minimum pretreatment used by most
14
C facilities), 52% asked laboratories to choose the pretreatment method for them, and 58% could not rank the reliability of at least one pretreatment. Ultrafiltration was highly popular, and purification by XAD resins seemed restricted to American researchers. Isolating and dating the amino acid hydroxyproline was perceived as the most reliable pretreatment, but is expensive, time-consuming and not widely available. Solid evidence supports that only molecular-level dating accommodates all known bone contaminants and guarantees complete removal of humic and fulvic acids and conservation substances, with three key areas of progress: (i) innovation and more funded research is required to develop affordable analytical chemistry that can handle low-mass samples of collagen amino acids, (ii) a certification agency overseeing dating-quality control is needed to enhance methodological reproducibility and dating accuracy among laboratories, and (iii) more cross-disciplinary work with better
14
C reporting etiquette will promote the integration of
14
C dating across disciplines. Those developments could conclude long-standing debates based on low-accuracy data used to build chronologies for animal domestications, human/megafauna extirpations and migrations, archaeology, palaeoecology, palaeontology and palaeoclimate models.
Synthesis of a novel amphoteric copolymer and its application as a dispersant for coal water slurry preparation
Authors: Du Lun , Zhang Guanghua , Yang Dongdong , Luo Jie , Liu Yewei , Zhang Wanbin , Zhang Ce , Li Junguo , Zhu Junfeng
Published: January 2021

In this work, a novel amphoteric copolymer named Poly(sodium p-styrenesulfonate–
co
-acrylic acid-
co
-diallyldimethylammonium chloride) (P(SS-
co
-AA-
co
-DMDAAC)) was synthesized via free radical polymerization. Afterwards, P(SS-
co
-AA-
co
-DMDAAC) was explored for use as a dispersant in coal water slurry (CWS) preparation. The structure of P(SS-
co
-AA-
co
-DMDAAC) was verified by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The synthetic conditions were optimized as the feed ratio of AA to SS was 1 : 1 (for Yulin coal) or 1.5 : 1 (for Yili coal), and DMDAAC dosage was 4.0 wt% (for Yulin coal) and 6.0 wt% (for Yili coal) toward total monomers. The performances of P(SS-
co
-AA-
co
-DMDAAC) as a dispersant for CWS were evaluated by various technologies, such as apparent viscosity, zeta potential, static stability and contact angle measurements. The results revealed that the optimized dosage of P(SS-
co
-AA-
co
-DMDAAC) in CWS preparation was 0.3 and 0.4 wt% for Yulin coal and Yili coal respectively. In this optimum condition, CWS prepared using P(SS-
co
-AA-
co
-DMDAAC) as dispersant showed a typical shear thinning behaviour and excellent stability, which are desired in industries. The rheological models also confirmed the pseudo-plastic characteristics of CWS. Finally, compared with the widely used anionic dispersant naphthalene sulphonate formaldehyde condensate (NSF) and poly(sodium p-styrenesulfonate) (PSS), P(SS-
co
-AA-
co
-DMDAAC) developed in this work exhibited better slurry making performance. The introduction of cationic functional groups promoted the adsorption of the dispersant, which further enhanced the electrostatic repulsion and steric hindrance among coal particles. Accordingly, the viscosity of CWS decreased and static stability enhanced.
Social contagion of affiliation in female macaques
Authors: Ostner Julia , Wilken Jana , Schülke Oliver
Published: January 2021

Social contagion of non-interactive behaviour is widespread among animals including humans. It is thought to facilitate behavioural synchronization and consequently group cohesion, coordination and opportunities for social learning. Contagion of interactive behaviour—particularly affiliation—has received much less attention. Here, we investigated in female rhesus macaques (
Macaca mulatta
) the effect of observing group members groom on a subject's subsequent grooming behaviour and the potential modulation of contagion by relationship quality and social status. We recorded behaviour after subjects witnessed a grooming event and compared it to behaviour in a control condition with the same individuals in proximity but in the absence of a stimulus grooming event. Compared to the control condition, after observing others groom, females engaged in a grooming interaction sooner, and were more likely to be the initiator and to take on the active groomer role. Dominance rank of the focal individual and more weakly also of the stimulus individuals affected the latency to the next grooming interaction of the focal subject. Latency to the next grooming interaction decreased with increasing rank of the subject potentially reflecting lower social constraints faced by high ranking individuals in this highly despotic species. Relationship quality between the subject and the stimulus individuals had no effect on latency to grooming. Collectively, our findings provide evidence for visual contagion of affiliation in rhesus macaques. Future studies should explore the systematic variation in contagion of interactive behaviour in relation to a gradient of social tolerance.
Microbiota dysbiosis in honeybee (
Apis mellifera
L
.
) larvae infected with brood diseases and foraging bees exposed to agrochemicals
Authors: Ye Man-Hong , Fan Shu-Hang , Li Xiao-Yuan , Tarequl Islam Mohd , Yan Chun-Xiang , Wei Wan-Hong , Yang Sheng-Mei , Zhou Bin
Published: January 2021

American foulbrood (AFB) disease and chalkbrood disease (CBD) are important bacterial and fungal diseases, respectively, that affect honeybee broods. Exposure to agrochemicals is an abiotic stressor that potentially weakens honeybee colonies. Gut microflora alterations in adult honeybees associated with these biotic and abiotic factors have been investigated. However, microbial compositions in AFB- and CBD-infected larvae and the profile of whole-body microbiota in foraging bees exposed to agrochemicals have not been fully studied. In this study, bacterial and fungal communities in healthy and diseased (AFB/CBD) honeybee larvae were characterized by amplicon sequencing of bacterial 16S rRNA gene and fungal internal transcribed spacer1 region, respectively. The bacterial and fungal communities in disordered foraging bees poisoned by agrochemicals were analysed. Our results revealed that healthy larvae were significantly enriched in bacterial genera
Lactobacillus
and
Stenotrophomonas
and the fungal genera
Alternaria
and
Aspergillus
. The enrichment of these microorganisms, which had antagonistic activities against the etiologic agents for AFB and CBD, respectively, may protect larvae from potential infection. In disordered foraging bees, the relative abundance of bacterial genus
Gilliamella
and fungal species
Cystofilobasidium macerans
were significantly reduced, which may compromise hosts' capacities in nutrient absorption and immune defence against pathogens. Significantly higher frequency of environmentally derived fungi was observed in disordered foraging bees, which reflected the perturbed microbiota communities of hosts. Results from PICRUSt and FUNGuild analyses revealed significant differences in gene clusters of bacterial communities and fungal function profiles. Overall, results of this study provide references for the composition and function of microbial communities in AFB- and CBD-infected honeybee larvae and foraging bees exposed to agrochemicals.
Rebound in functional distinctiveness following warming and reduced fishing in the North Sea
Authors: Murgier Juliette , McLean Matthew , Maire Anthony , Mouillot David , Loiseau Nicolas , Munoz François , Violle Cyrille , Auber Arnaud
Published: January 2021

Functionally distinct species (i.e. species with unique trait combinations in the community) can support important ecological roles and contribute disproportionately to ecosystem functioning. Yet, how functionally distinct species have responded to recent climate change and human exploitation has been widely overlooked. Here, using ecological traits and long-term fish data in the North Sea, we identified functionally distinct and functionally common species, and evaluated their spatial and temporal dynamics in relation to environmental variables and fishing pressure. Functionally distinct species were characterized by late sexual maturity, few, large offspring, and high parental care, many being sharks and skates that play critical roles in structuring food webs. Both functionally distinct and functionally common species increased in abundance as ocean temperatures warmed and fishing pressure decreased over the last three decades; however, functionally distinct species increased throughout the North Sea, but primarily in southern North Sea where fishing was historically most intense, indicating a rebound following fleet decommissioning and reduced harvesting. Yet, some of the most functionally distinct species are currently listed as threatened by the IUCN and considered highly vulnerable to fishing pressure. Alarmingly these species have not rebounded. This work highlights the relevance and potential of integrating functional distinctiveness into ecosystem management and conservation prioritization.
The evolution and genetics of sexually dimorphic ‘dual’ mimicry in the butterflyElymnias hypermnestra
Authors: Ruttenberg Dee M. , VanKuren Nicholas W. , Nallu Sumitha , Yen Shen-Horn , Peggie Djunijanti , Lohman David J. , Kronforst Marcus R.
Published: January 2021

Sexual dimorphism is a major component of morphological variation across the tree of life, but the mechanisms underlying phenotypic differences between sexes of a single species are poorly understood. We examined the population genomics and biogeography of the common palmflyElymnias hypermnestra, a dual mimic in which female wing colour patterns are either dark brown (melanic) or bright orange, mimicking toxicEuploeaandDanausspecies, respectively. As males always have a melanic wing colour pattern, this makesE. hypermnestraa fascinating model organism in which populations vary in sexual dimorphism. Population structure analysis revealed that there were three genetically distinctE. hypermnestrapopulations, which we further validated by creating a phylogenomic species tree and inferring historical barriers to gene flow. This species tree demonstrated that multiple lineages with orange females do not form a monophyletic group, and the same is true of clades with melanic females. We identified two single nucleotide polymorphisms (SNPs) near the colour patterning geneWntAthat were significantly associated with the female colour pattern polymorphism, suggesting that this gene affects sexual dimorphism. GivenWntA's role in colour patterning across Nymphalidae,E. hypermnestrafemales demonstrate the repeatability of the evolution of sexual dimorphism.
Firstborn sex defines early childhood growth of subsequent siblings
Authors: Schäfer Samuel , Sundling Felicia , Liu Anthony , Raubenheimer David , Nanan Ralph
Published: January 2021

Animal studies have shown that maternal resource allocation can be sex-biased in order to maximize reproductive success, yet this basic concept has not been investigated in humans. In this study, we explored relationships between maternal factors, offspring sex and prenatal and postnatal weight gain. Sex-specific regression models not only indicated that maternal ethnicity impacted male (n= 2456) and female (n= 1871) childrens postnatal weight gain differently but also that parity and mode of feeding influenced weight velocity of female (β± s.e. = −0.31 ± 0.11 kg,p= 0.005;β± s.e. = −0.37 ± 0.11 kg,p< 0.001) but not male offspring. Collectively, our findings imply that maternal resource allocation to consecutive offspring increases after a male firstborn. The absence of this finding in formula fed children suggests that this observation could be mediated by breast milk. Our results warrant further mechanistic and epidemiological studies to elucidate the role of breastfeeding on the programming of infant growth as well as of metabolic and cardiovascular diseases, with potential implications for tailoring infant formulae according to sex and birth order.
Learning the same motor task twice impairs its retention in a time- and dose-dependent manner
Authors: Hamel R. , Dallaire-Jean L. , De La Fontaine É. , Lepage J. F. , Bernier P. M.
Published: January 2021

Anterograde interference emerges when
two differing tasks
are learned in close temporal proximity, an effect repeatedly attributed to a competition between differing task memories. However, recent development alternatively suggests that initial learning may trigger a refractory period that occludes neuroplasticity and impairs subsequent learning, consequently mediating interference independently of memory competition. Accordingly, this study tested the hypothesis that interference can emerge when
the same motor task is being learned twice,
that is when competition between memories is prevented. In a first experiment, the inter-session interval (ISI) between two identical motor learning sessions was manipulated to be 2 min, 1 h or 24 h. Results revealed that retention of the second session was impaired as compared to the first one when the ISI was 2 min but not when it was 1 h or 24 h, indicating a time-dependent process. Results from a second experiment replicated those of the first one and revealed that adding a third motor learning session with a 2 min ISI further impaired retention, indicating a dose-dependent process. Results from a third experiment revealed that the retention impairments did not take place when a learning session was preceded by simple rehearsal of the motor task without concurrent learning, thus ruling out fatigue and confirming that retention is impaired specifically when preceded by a learning session. Altogether, the present results suggest that competing memories is not the sole mechanism mediating anterograde interference and introduce the possibility that a time- and dose-dependent refractory period—independent of fatigue—also contributes to its emergence. One possibility is that learning transiently perturbs the homeostasis of learning-related neuronal substrates. Introducing additional learning when homeostasis is still perturbed may not only impair performance improvements, but also memory formation.
Early-life behaviour predicts first-year survival in a long-distance avian migrant
Authors: Rotics Shay , Turjeman Sondra , Kaatz Michael , Zurell Damaris , Wikelski Martin , Sapir Nir , Fiedler Wolfgang , Eggers Ute , Resheff Yehezkel S. , Jeltsch Florian , Nathan Ran
Published: January 2021

Early-life conditions have critical, long-lasting effects on the fate of individuals, yet early-life activity has rarely been linked to subsequent survival of animals in the wild. Using high-resolution GPS and body-acceleration data of 93 juvenile white storks (Ciconia ciconia), we examined the links between behaviour during both pre-fledging and post-fledging (fledging-to-migration) periods and subsequent first-year survival. Juvenile daily activity (based on overall dynamic body acceleration) showed repeatable between-individual variation, the juveniles' pre- and post-fledging activity levels were correlated and both were positively associated with subsequent survival. Daily activity increased gradually throughout the post-fledging period, and the relationship between post-fledging activity and survival was stronger in individuals who increased their daily activity level faster (an interaction effect). We suggest that high activity profiles signified individuals with increased pre-migratory experience, higher individual quality and perhaps more proactive personality, which could underlie their superior survival rates. The duration of individuals’ fledging-to-migration periods had a hump-shaped relationship with survival: higher survival was associated with intermediate rather than short or long durations. Short durations reflect lower pre-migratory experience, whereas very long ones were associated with slower increases in daily activity level which possibly reflects slow behavioural development. In accordance with previous studies, heavier nestlings and those that hatched and migrated earlier had increased survival. Using extensive tracking data, our study exposed new links between early-life attributes and survival, suggesting that early activity profiles in migrating birds can explain variation in first-year survival.
Sympatry drives colour and song evolution in wood-warblers (Parulidae)
Authors: Simpson Richard K. , Wilson David R. , Mistakidis Allison F. , Mennill Daniel J. , Doucet Stéphanie M.
Published: January 2021

Closely related species often exhibit similarities in appearance and behaviour, yet when related species exist in sympatry, signals may diverge to enhance species recognition. Prior comparative studies provided mixed support for this hypothesis, but the relationship between sympatry and signal divergence is likely nonlinear. Constraints on signal diversity may limit signal divergence, especially when large numbers of species are sympatric. We tested the effect of sympatric overlap on plumage colour and song divergence in wood-warblers (Parulidae), a speciose group with diverse visual and vocal signals. We also tested how number of sympatric species influences signal divergence. Allopatric species pairs had overall greater plumage and song divergence compared to sympatric species pairs. However, among sympatric species pairs, plumage divergence positively related to the degree of sympatric overlap in males and females, while male song bandwidth and syllable rate divergence negatively related to sympatric overlap. In addition, as the number of species in sympatry increased, average signal divergence among sympatric species decreased, which is likely due to constraints on warbler perceptual space and signal diversity. Our findings reveal that sympatry influences signal evolution in warblers, though not always as predicted, and that number of sympatric species can limit sympatry's influence on signal evolution.
Impaired sensory evidence accumulation and network function in Lewy body dementia
Authors: O’Callaghan Claire , Firbank Michael , Tomassini Alessandro , Schumacher Julia , O’Brien John T , Taylor John-Paul
Published: January 2021

Deficits in attention underpin many of the cognitive and neuropsychiatric features of Lewy body dementia. These attention-related symptoms remain difficult to treat and there are many gaps in our understanding of their neurobiology. An improved understanding of attention-related impairments can be achieved via mathematical modelling approaches, which identify cognitive parameters to provide an intermediate level between observed behavioural data and its underlying neural correlate. Here, we apply this approach to identify the role of impaired sensory evidence accumulation in the attention deficits that characterise Lewy body dementia. In 31 people with Lewy body dementia (including 13 Parkinson’s disease dementia and 18 dementia with Lewy bodies cases), 16 people with Alzheimer’s disease, and 23 healthy controls, we administered an attention task whilst they underwent functional 3T MRI. Using hierarchical Bayesian estimation of a drift diffusion model, we decomposed task performance into drift rate and decision boundary parameters. We tested the hypothesis that the drift rate – a measure of the quality of sensory evidence accumulation – is specifically impaired in Lewy body dementia, compared to Alzheimer’s disease. We further explored whether trial-by-trial variations in the drift rate related to activity within the default and dorsal attention networks, to determine whether altered activity in these networks was associated with slowed drift rates in Lewy body dementia. Our results revealed slower drift rates in the Lewy body dementia compared to the Alzheimer’s disease group, whereas the patient groups were equivalent for their decision boundaries. The patient groups were reduced relative to controls for both parameters. This highlights sensory evidence accumulation deficits as a key feature that distinguishes attention impairments in Lewy body dementia, consistent with impaired ability to efficiently process information from the environment to guide behaviour. We also found that the drift rate was strongly related to activity in the dorsal attention network across all three groups, whereas the Lewy body dementia group showed a divergent relationship relative to the Alzheimer’s disease and control groups for the default network, consistent with altered default network modulation being associated with impaired evidence accumulation. Together, our findings reveal impaired sensory evidence accumulation as a specific marker of attention problems in Lewy body dementia, which may relate to large-scale network abnormalities. By identifying impairments in a specific sub-process of attention, these findings will inform future exploratory and intervention studies that aim to understand and treat attention-related symptoms that are a key feature of Lewy body dementia.
Targeting glucose metabolism sensitizes pancreatic cancer to MEK inhibition
Authors: Yan Liang , Tu Bo , Yao Jun , Gong Jing , Carugo Alessandro , Bristow Christopher A. , Wang Qiuyun , Zhu Cihui , Dai Bingbing , Kang Ya’an , Han Leng , Feng Ningping , Jin Yanqing , Fleming Jason , Heffernan Timothy P. , Yao Wantong , Ying Haoqiang
Published: January 2021

Pancreatic ductal adenocarcinoma (PDAC) is almost universally lethal. A critical unmet need exists to explore essential susceptibilities in PDAC and identify druggable targets for tumor maintenance. This is especially challenging in the context of PDAC, in which activating mutations of KRAS oncogene (KRAS*) dominate the genetic landscape. By using an inducibleKrasG12D-drivenp53deficient PDAC mouse model (iKras model), we demonstrate that RAF-MEK-MAPK signaling is the major effector for oncogenic Kras-mediated tumor maintenance. However, MEK inhibition has minimal therapeutic effect as single agent for PDAC both in vitro and in vivo. Although MEK inhibition partially downregulates the transcription of glycolysis genes, it surprisingly fails to suppress the glycolysis flux in PDAC cell, which is a major metabolism effector of oncogenic KRAS. Accordingly, In vivo genetic screen identified multiple glycolysis genes as potential targets that may sensitize tumor cells to MAPK inhibition. Furthermore, inhibition of glucose metabolism with low dose 2-deoxyglucose (2DG) in combination with MEK inhibitor dramatically induces apoptosis in KrasG12D-driven PDAC cell in vitro, inhibits xenograft tumor growth and prolongs the overall survival of genetically engineered mouse PDAC model. Molecular and metabolism analyses indicate that co-targeting glycolysis and MAPK signaling results in apoptosis via induction of lethal ER stress. Together, our work suggests that combinatory inhibition of glycolysis and MAPK pathway may serve as an alternative approach to target KRAS-driven PDAC.
Inter- and intra-specific variation in hair cortisol concentrations of Neotropical bats
Authors: Sandoval-Herrera Natalia I. , Mastromonaco Gabriela F. , Becker Daniel J. , Simmons Nancy B. , Welch Kenneth C.
Published: January 2021

Quantifying hair cortisol has become popular in wildlife ecology for its practical advantages for evaluating health. Before hair cortisol levels can be reliably interpreted however, it is key to first understand the intrinsic factors explaining intra- and interspecific variation. Bats are an ecologically diverse group of mammals that allow studying such variation. Given that many bat species are threatened or have declining populations in parts of their range, non-invasive tools for monitoring colony health and identifying cryptic stressors are needed to efficiently direct conservation efforts. Here we describe intra- and interspecific sources of variation in hair cortisol levels in 18 Neotropical bat species from Mexico and Belize. We found that fecundity is an important ecological trait explaining interspecific variation in bat hair cortisol. Other ecological variables such as colony size, roost durability, and basal metabolic rate did not explain hair cortisol variation among species. At the individual level, females exhibited higher hair cortisol levels than males, and the effect of body mass varied among species. Overall, our findings help validate and accurately apply hair cortisol as a monitoring tool in free-ranging bats.
High regional and intra-generic variation in susceptibility to mass bleaching in Indo-Pacific coral species
Authors: Muir Paul R. , Done Terence , Aguirre J. David
Published: January 2021

Aim

Mass bleaching is a major threat to reef-building corals and the ecosystems they underpin. Here, we identified regional variation in the nature of this threat in terms of the bleaching-susceptibility of individual coral species on some Indian Ocean and Pacific Ocean reefs.

Location

22 sites in the central Great Barrier Reef, Australia (GBR) and 30 sites in the central Maldives Archipelago (MA).

Time period

2002 for the GBR and 2016 for the MA.

Major taxa studied

Corals (Order Scleractinia).

Methods

Following marine heat-wave conditions, timed in-situ surveys were used to record bleaching responses (tissue colour) of large samples of individual coral colonies. Responses of 106 shared species were analysed for sites with similar levels of temperature stress, depth of occurrence and mortality. In each region, phylogenetic mixed models were used to partition the effects on responses of species of deep-time phylogeny, contemporary history and local-scale, among-site variability.

Results

Relative susceptibility to bleaching varied widely between regions: only 27 of the 106 shared species were in the same quartile for relative susceptibility in both regions. Few species were highly susceptible in both regions. Closely related species varied widely in their individual susceptibilities. Phylogenetic effects were moderate in both regions, but contemporary phenotypic effects indicative of recent evolution and acclimatization were greater in the MA, consistent with a stronger history of recent bleaching.

Main conclusions

The high regional and intra-generic variation in coral bleaching-susceptibility described here suggests there may be important differences in the extent to which these Indian and Pacific Ocean coral populations are exhibiting responses to deep-time evolutionary changes on the one hand, versus recent adaptation, on the other. There is a concerning scarcity of this type of data, by which coral species most at risk from bleaching in particular regions may be more accurately identified.
Interhemispheric connectivity endures across species: An allometric exposé on the corpus callosum
Authors: Cipollini Ben , Cottrell Garrison W.
Published: January 2021

Rilling & Insel have argued that in primates, bigger brains have proportionally fewer anatomical interhemispheric connections, leading to reduced functional connectivity between the hemispheres (1). They based this on a comparison between surface areas of the corpus callosum and cortex rather than estimating connection counts, while leaving out other quantities also dependent on brain size such as callosal fiber density, neuron density, and number of functional areas.

We use data from the literature to directly estimate connection counts. First, we estimate callosal fiber density as a function of brain size. We validate this by comparing out-of-sample human data to our function’s estimate. We then mine the literature to obtain function estimates for all other quantities, and use them to estimate intra- and interhemispheric white matter connection counts as a function of brain size.

The results show a much larger decrease in the scaling of interhemispheric to intrahemispheric connections than previously estimated. However, we hypothesize that raw connection counts are the wrong quantity to be estimating when considering functional connectivity. Instead, we hypothesize that functional connectivity is related to connection counts relative to the number of cortical areas.

Accordingly, we estimate inter-area connection counts for intra- and interhemispheric connectivity and find no difference in how they scale with brain size. We find that, on average, an interhemispheric inter-area connection contains 3-8x more connections than an intrahemispheric inter-area connection, regardless of brain size. In doing so, we find that the fiber count of the human corpus callosum has been underestimated by 20%.

Significance Statement

There are arguments in the literature that larger brains have proportionally fewer interhemispheric connections. We find that the decrease is even larger than previously estimated. However, we argue that this quantity is the wrong thing to measure: Rather, we should measure functional connectivity between cortical areas. We show that the ratio of interhemispheric and intrahemispheric connectivity between cortical areas is constant across mammalian species. These findings are consistent with a growing literature that suggest interhemispheric connectivity is special across all primate species.
Hydroxyapatite pellets as versatile model surfaces for systematic studies on enamel
Authors: Mischo Johannes , Faidt Thomas , McMillan Ryan B. , Dudek Johanna , Gunaratnam Gubesh , Bayenat Pardis , Holtsch Anne , Spengler Christian , Müller Frank , Hähl Hendrik , Bischoff Markus , Hannig Matthias , Jacobs Karin
Published: January 2021

Research into materials for medical application draws inspiration from naturally occurring or synthesized surfaces, just like many other research directions. For medical application of materials, particular attention has to be paid to biocompatibility, osseointegration and bacterial adhesion behavior. To understand their properties and behavior, experimental studies with natural materials such as teeth are strongly required. The results, however, may be highly case-dependent because natural surfaces have the disadvantage of being subject to wide variations, for instance in their chemical composition, structure, morphology, roughness, and porosity. A synthetic surface which mimics enamel in its performance with respect to bacterial adhesion and biocompatibility would, therefore, facilitate systematic studies much better. In this study, we discuss the possibility of using hydroxyapatite (HAp) pellets to simulate the surfaces of teeth and show the possibility and limitations of using a model surface. We performed single-cell force spectroscopy with singleStaphylococcus aureuscells to measure adhesion-related parameters such as adhesion force and rupture length of adhesins binding to HAp and enamel. We also examine the influence of blood plasma and saliva on the adhesion properties ofS. aureus. The results of these measurements are matched to water wettability, elemental composition of the samples and the change in the macromolecules adsorbed over time. We found that the adhesion properties ofS. aureuswere similar on both samples under all conditions: Significant decreases in adhesion strength were found equally in the presence of saliva or blood plasma on both surfaces. We therefore conclude that HAp pellets are a good alternative for natural dental material. This is especially true when slight variations in the physicochemical properties of the natural materials may affect the experimental series.
The artification of wine: lessons from the fine wines of Bordeaux and Burgundy
Authors: Joy Annamma , LaTour Kathryn A. , Charters Steve John , Grohmann Bianca , Peña-Moreno Camilo
Published: January 2021

Purpose

In this paper, the authors argue that fine wines can be considered art and as such can be awarded luxury status. The authors discuss the processes of artification, through which such wines are recognized as art (Shapiro and Heinich, 2012), and heritagization, in which the cultural differentiation implicit in the concept of terroir (the various elements of a microclimate that contribute to a wine's specific attributes) connects a wine to its history and provenance. The investigation focuses specifically on fine wines from Bordeaux and Burgundy, which are renowned worldwide for their depth and flavors. What traits are intrinsic to the definition of art, and what social processes culminate in transforming an entity from nonart to art?

Design/methodology/approach

It is a conceptual paper that requires blending several viewpoints to present the authors’ own viewpoints.

Findings

This study aims to address the above questions and argues that fine wines, as a source of aesthetic pleasure, are themselves an art form.

Research limitations/implications

The implications for producers of fine wines and other artisanal products seeking to elevate brand awareness are discussed.

Practical implications

The findings of this study are of interest to wine scholars as well as wineries. They provide evidence as to how artification occurs.

Originality/value

While there are papers that address the issue of artification and heritagization individually, the authors bring to bear the importance of both concepts on specific wine regions in France: Burgundy and Bordeaux.
Composite nonlinear H∞ based output feedback controller for an un-crewed helicopter in its hover flight
Authors: Thomas Femi , Johnson Mija Salomi
Published: January 2021

Purpose

This paper aims to propose output feedback-based control algorithms for the flight control system of a scaled, un-crewed helicopter in its hover flight mode.

Design/methodology/approach

The proposed control schemes are based on H∞ control and composite nonlinear control. The gains of the output feedback controllers are obtained as the solution of a set of linear matrix inequalities (LMIs).

Findings

In the proposed schemes, the finite-time convergence of system states to trim condition is achieved with minimum deviation from the steady-state. As the proposed composite nonlinear output feedback design improves the transient response, it is well suited for a scaled helicopter flight. The use of measured output vector instead of the state vector or its estimate for feedback provides a simple control structure and eliminates the need for an observer in real-time application. The proposed control strategies are relevant to situations in which a simple controller is essential due to economic factors, reliability and hardware implementation constraints.

Practical implications

The proposed control strategies are relevant to situations in which a simple controller is essential due to economic factors, reliability and hardware implementation constraints. They also have significance in applications where the number of measurement quantities needs to be minimized such as in a fully functional rotor-craft unmanned aerial vehicle.

Social implications

The developed output feedback control algorithms can be used in small-scale helicopters for numerous civilian and military applications.

Originality/value

This work addresses the LMI-based formulation and solution of an output feedback controller for a hovering un-crewed helicopter. The stability and robustness of the closed-loop system are proved mathematically and the performance of the proposed schemes is compared with an existing strategy via simulation studies.
Web-store image dimensions and online retail customer loyalty: investigating mediators and moderators
Authors: Soni Pavleen
Published: January 2021

Purpose

In an era of burgeoning activity in online retail in India, the role of web-store design is paramount. Web-store design elements such as website functionality, brand assortment and product quality are expected to generate customer loyalty.

Design/methodology/approach

Using data collected from 553 students from two universities in north India, the present study investigates the indirect effect of web-store dimensions (through website functionality, brand assortment and product quality) on online store loyalty via an enjoyment state (flow) and customer satisfaction. Serial mediation has been analysed through PROCESS macro developed by Hayes version 3.0. In addition to this, the moderating role of gender and purchase frequency has also been investigated.

Findings

The present study renders support to serial mediation between website functionality, flow, customer satisfaction and loyalty. However, the path between brand assortment and loyalty is more strongly mediated by customer satisfaction only. Males experience less flow as compared to females while handling brand assortment on websites. The three-way interaction between brand assortment, gender and purchase frequency is also statistically significant.

Originality/value

The study examines the manner in which online retailers can choose to build customer loyalty when they try to build retail image using web store functionality and /or product/brand assortments. The study offers insights to retailers about how and when to focus on hedonism versus customer satisfaction or both of them in conjunction to enhance customer loyalty. This study is important as it investigates the relationships in Indian scenario witnessing a high rate of growth in online retail which can tremendously affect these relationships.
Sustainability responses to climate-smart adaptation in Africa: implication for food security among farm households in the Central Region of Ghana
Authors: Dadzie Samuel Kwesi Ndzebah , Inkoom Emmanuel W. , Akaba Selorm , Annor-Frempong Festus , Afful James
Published: January 2021

Purpose

The consequences of extreme climatic events that threaten food security have created the urgent need to properly adopt climate-smart adaptation techniques to improve productivity. The study examined the sustainability responses to climate-smart adaptation and the implication it has for explaining the food security situations among farm households in the Central Region of Ghana.

Design/methodology/approach

We estimated Heckit treatment effect model to analyse cross-sectional data collected from randomly selected farmers in the Central Region.

Findings

Analysis of farm sustainability index suggests that farmers' agricultural practices in response to climate change are lowly or moderately sustainable. We further found that while majority of the farm households are severely food insecure or food insecure with hunger, only about one-third are food insecure without hunger and the remaining few being food secure. The sustainability of farm practices is being impacted by the farmers’ choice of climate smart adaptation measures at the farm level. Consequently, the farm households' food security situation is found to be improved when sustainable farming practices are employed in the face of managing climate change effects.

Practical implications

Conclusions drawn from the study findings give rooms for policy implications that suggest responsibilities for policymakers, farmers and other stakeholders to promote CSA practices in food crop production in Ghana. These policy implications will contribute to improve crop productivity, increase incomes and thus enhance food security among farm families. Awareness campaign about benefits of CSA practices and technologies need to be strengthened among farmers in Ghana by government and NGOs that matter in promoting farm resilience to climate change. Given the important impacts of sustainable farm practices on household food security situation, policies that seek to build the adaptive capacity of farmers to climate vulnerability impacts should take into consideration the sustainability dimensions of the adaptation and mitigation measures to be advocated for use at farm levels.

Originality/value

Our paper contributes to literature knowledge on climate-smart adaptation practices effect on food security as evidenced in some recent literature. The paper makes a unique contribution by highlighting the food security implication of the sustainability impact of CSA practices, thereby exploring sustainability as an impact pathway between climate smart adaptations practices and food security in a developing country like Ghana. We approached our study aiming at making new contribution by introducing in the study implementation a quasi-experimental research design which future studies on impacts of climate smart adaptation practices can replicate.