bluuebunny/crossref_metadata_2025 huggingface dataset:
Limits of intravascular contrast extravasation on computed tomography scan to define the need for pelvic angioembolization in pelvic blunt trauma: a specific assessment on the risk of false positives
Authors: Ramin Séverin , Hermida Margaux , Millet Ingrid , Murez Thibault , Monnin Valerie , Hamoui Mazen , Capdevila Xavier , Charbit Jonathan
Published: June 2018

BACKGROUND

The objective was to assess the predictive performance of different intravascular contrast extravasation (ICE) characteristics for need for pelvic transarterial embolization (TAE) to determine the risk factors of false positives.

METHODS

A retrospective study was performed in our trauma center between 2010 and 2015. All severe trauma patients with pelvic fracture were included. Pelvic ICE characteristics on computed tomography (CT) scan were studied: arterial (aS2
ICE), portal surface (pS2
ICE), and extension (exS2
ICE) anatomic relationships. The overall predictive performance of ICE surfaces for pelvic TAE was analyzed using receiver operating characteristic curves. The analysis focused on risk factors for false positives.

RESULTS

Among 311 severe trauma patients with pelvic ring fracture (mean age, 42 ± 19 years; mean Injury Severity Score, 27 ± 19), 94 (30%) had at least one pelvic ICE on the initial CT scan. Patients requiring pelvic TAE had significantly larger aS2
ICE and pS2
ICE than others (p = 0.001 and p = 0.035, respectively). The overall ability of ICE surfaces to predict pelvic TAE was modest (aS2
ICE area under the receiver operating characteristic curve, 0.76 [95% confidence interval, 0.64–0.90]; p = 0.011) or nonsignificant (pS2
ICE and exS2
ICE). The high-sensitivity threshold was defined as aS2
ICE 20 mm2 or more. Using this threshold, 76% of patients were false positives. Risk factors for false positives were admission systolic blood pressure of 90 mm Hg or greater (63% vs 20%; p = 0.03) and low transfusion needs (63% vs 10%; p = 0.009), extravasation in contact with complex bone fracture (78% vs 30%; p = 0.008), or the absence of a direct relationship between extravasation and a large retroperitoneal hematoma (100% vs 38%; p < 0.001).

CONCLUSION

A significant pelvic ICE during the arterial phase does not guarantee the need for pelvic TAE. Three quarters of patients with aS2
ICE of 20 mm2 or more did not need pelvic TAE. Several complementary CT scan criteria will help to identify this risk of false positives to determine adequate hemostatic pelvic procedures.

LEVEL OF EVIDENCE

Therapeutic study, level IV.
No wire? No problem: Resuscitative endovascular balloon occlusion of the aorta can be performed effectively and more rapidly with a wire-free device
Authors: Romagnoli Anna Noel , Teeter William , Wasicek Philip , Gamble William Bryan , Hu Peter , Stein Deborah , Scalea Thomas , Brenner Megan
Published: June 2018

BACKGROUND

A wire-free device is available for resuscitative endovascular balloon occlusion of the aorta (REBOA) providing aortic occlusion (AO) without lengthy platform guide-wires and large sheaths.

METHODS

This was a retrospective, single-institution review of patients who received REBOA from May 2014 to September 2017. Timing of procedural steps was measured in seconds using time-stamped videography.

RESULTS

Seventy-four patients received REBOA: 29 with a platform guidewire, 12-Fr sheath, and balloon catheter (W group), and 45 with a 7-Fr sheath and wire-free device (WF group). Mean age (p = 0.22) and ISS (p = 0.80) were similar between groups. Fifty-nine patients received REBOA at Zone 1, 15 patients at Zone 3. There was no difference in median [interquartile range] time to common femoral artery (CFA) access between the WF (194 [98–313] seconds) and W (193 [126–280] seconds) groups (p = 0.96). Both median time to AO after CFA access (WF, 158 [109–264] seconds vs. W, 307 [222–390] seconds, p < 0.001) and median total procedural time (WF, 366 [263–596] seconds vs. W, 511 [441–597] seconds; p = 0.012) were significantly shorter with the wire-free system. The rates of percutaneous versus open CFA access was not different between groups (p = 0.48). Both groups had a similar physiologic response to AO as measured by pre- and post-AO SBP (p = 0.86). Overall mortality rate was 74%, 90% in the W group, and 64% in the WF group (p = 0.027). The procedure-related complication rate was not significantly different between groups with regard to compartment syndrome (W, 3% vs. WF, 4%, p = 1.0), access-related complications (W, 0 vs. WF, 6%, p = 0.28), or systemic complication (W, 0 vs. WF, 9%, p = 0.15).

CONCLUSION

Once CFA access is obtained, AO with a smaller wire-free device reduces procedural time by approximately 50%. When perfusion to proximal organs is essential, the seconds saved to achieve AO may contribute to improved mortality. Time to obtain CFA access is not dependent on introducer sheath size.

LEVEL OF EVIDENCE

Therapeutic, level V.
Transcranial Direct Current Stimulation in the Acute Depressive Episode
Authors: Borrione Lucas , Moffa Adriano H. , Martin Donel , Loo Colleen K. , Brunoni Andre R.
Published: June 2018

Major depressive disorder is a severe, refractory mental disorder. Only one third of patients treated with antidepressants achieve remission after 3 trials, while subject to adverse effects. Therefore, the investigation of alternative treatments is paramount. The aim of this systematic review was to summarize the most recent evidence of transcranial direct current stimulation (tDCS) intervention for the acute phase of major depressive disorder. A PubMed search was performed including the terms “transcranial direct current stimulation” OR “transcranial direct stimulation” OR “tDCS” AND “major depressive disorder” OR “major depression” OR “depression” AND “trial.” The search was conducted from inception until February 2018. Our search yielded initially 165 results, and 14 randomized clinical trials were included according to eligibility criteria. Most studies were pilot studies, with mixed findings. Two large randomized clinical trials recently published also presented primary negative findings. Study protocols usually used anodal left/cathodal right dorsolateral prefrontal cortex stimulation, 1 to 2.5 mA, and 5 to 20 tDCS sessions. We discuss the limitations of the included trials, such as sample and tDCS parameters heterogeneity between studies. To conclude, tDCS seems to be safe and devoid of serious adverse effects, although robust efficacy has not been consistently demonstrated in clinical trials assessing an acute treatment course of up to 4 weeks. Further directions are discussed, such as parameter individualization, investigation of biological markers, and home-use tDCS.
Natural hybridization between divergent lineages in a selfing hermaphroditic fish
Authors: Tatarenkov Andrey , Earley Ryan L. , Taylor D. Scott , Davis William P. , Avise John C.
Published: June 2018

By definition, mating between individuals is infrequent in highly selfing organisms, and so too, therefore, hybridization should be rare between genetically divergent lineages in predominantly self-fertilizing species. Notwithstanding these expectations, here we report a remarkable case of natural hybridization between highly diverged phylogeographic lineages of the mangrove rivulus, a small killifish that reproduces predominantly by self-fertilization and typically is found as highly homozygous lines in most parts of its extensive geographical range. Two distinctive genetic lineages (Kryptolebias marmoratusand a ‘Central clade' closely related toK. hermaphroditus) previously were not known in sympatry, but were found by us to co-occur on San Salvador, Bahamas. Genetic analyses of a mitochondrial and multiple nuclear markers determined the direction of a cross producing a hybrid fish. Furthermore, we show that this hybrid individual was viable, as it successfully reproduced by self-fertilization for two generations. Additional sampling of this population will be necessary to determine if backcrossing of hybrids to the parental lineages occurs in nature and to analyse whether such backcross progeny are viable. Application of the biological species concept (BSC) is traditionally difficult in clonally reproducing organisms. Our results show that although mangrove rivulus fish are mostly highly selfing in nature (resulting in isogenic, effectively clonal and homozygous progeny), classification within this taxonomic complex need not be incompatible with the BSC.
Loss in the making: absence of pelvic fins and presence of paedomorphic pelvic girdles in a Late Devonian antiarch placoderm (jawed stem-gnathostome)
Authors: Charest France , Johanson Zerina , Cloutier Richard
Published: June 2018

Within jawed vertebrates, pelvic appendages have been modified or lost repeatedly, including in the most phylogenetically basal, extinct, antiarch placoderms. One Early Devonian basal antiarch,
Parayunnanolepis
, possessed pelvic girdles, suggesting the presence of pelvic appendages at the origin of jawed vertebrates; their absence in more derived antiarchs implies a secondary loss. Recently, paired female genital plates were identified in the Late Devonian antiarch,
Bothriolepis canadensis
, in the position of pelvic girdles in other placoderms. We studied these putative genital plates along an ontogenetic series of
B. canadensis
; ontogenetic changes in their morphology, histology and elemental composition suggest they represent endoskeletal pelvic girdles composed of perichondral and endochondral bone. We suggest that pelvic fins of derived antiarchs were lost, while pelvic girdles were retained, but reduced, relative to
Parayunnanolepis
. This indicates developmental plasticity and evolutionary lability in pelvic appendages, shortly after these elements evolved at the origin of jawed vertebrates.
A unified stochastic modelling framework for the spread of nosocomial infections
Authors: López-García Martín , Kypraios Theodore
Published: June 2018

Over the last years, a number of stochastic models have been proposed for analysing the spread of nosocomial infections in hospital settings. These models often account for a number of factors governing the spread dynamics: spontaneous patient colonization, patient–staff contamination/colonization, environmental contamination, patient cohorting or healthcare workers (HCWs) hand-washing compliance levels. For each model, tailor-designed methods are implemented in order to analyse the dynamics of the nosocomial outbreak, usually by means of studying quantities of interest such as the reproduction number of each agent in the hospital ward, which is usually computed by means of stochastic simulations or deterministic approximations. In this work, we propose a highly versatile stochastic modelling framework that can account for all these factors simultaneously, and which allows one to exactly analyse the reproduction number of each agent at the hospital ward during a nosocomial outbreak. By means of five representative case studies, we show how this unified modelling framework comprehends, as particular cases, many of the existing models in the literature. We implement various numerical studies via which we (i) highlight the importance of maintaining high hand-hygiene compliance levels by HCWs, (ii) support infection control strategies including to improve environmental cleaning during an outbreak and (iii) show the potential of some HCWs to act as super-spreaders during nosocomial outbreaks.
Substrate deformations induce directed keratinocyte migration
Authors: Zarkoob Hoda , Chinnathambi Sathivel , Selby John C. , Sander Edward A.
Published: June 2018

Cell migration is an essential part of many (patho)physiological processes, including keratinocyte re-epithelialization of healing wounds. Physical forces and mechanical cues from the wound bed (in addition to biochemical signals) may also play an important role in the healing process. Previously, we explored this possibility and found that polyacrylamide (PA) gel stiffness affected human keratinocyte behaviour and that mechanical deformations in soft (approx. 1.2 kPa) PA gels produced by neighbouring cells appeared to influence the process ofde novoepithelial sheet formation. To clearly demonstrate that keratinocytes do respond to such deformations, we conducted a series of experiments where we observed the response of single keratinocytes to a prescribed local substrate deformation that mimicked a neighbouring cell or evolving multicellular aggregate via a servo-controlled microneedle. We also examined the effect of adding either Y27632 or blebbistatin on cell response. Our results indicate that keratinocytes do sense and respond to mechanical signals comparable to those that originate from substrate deformations imposed by neighbouring cells, a finding that could have important implications for the process of keratinocyte re-epithelialization that takes place during wound healing. Furthermore, the Rho/ROCK pathway and the engagement of NM II are both essential to substrate deformation-directed keratinocyte migration.
Constitutive regulation of mitochondrial morphology by Aurora A kinase depends on a predicted cryptic targeting sequence at the N-terminus
Authors: Grant Rhys , Abdelbaki Ahmed , Bertoldi Alessia , Gavilan Maria P. , Mansfeld Jörg , Glover David M. , Lindon Catherine
Published: June 2018

Aurora A kinase (AURKA) is a major regulator of mitosis and an important driver of cancer progression. The roles of AURKA outside of mitosis, and how these might contribute to cancer progression, are not well understood. Here, we show that a fraction of cytoplasmic AURKA is associated with mitochondria, co-fractionating in cell extracts and interacting with mitochondrial proteins by reciprocal co-immunoprecipitation. We have also found that the dynamics of the mitochondrial network are sensitive to AURKA inhibition, depletion or overexpression. This can account for the different mitochondrial morphologies observed in RPE-1 and U2OS cell lines, which show very different levels of expression of AURKA. We identify the mitochondrial fraction of AURKA as influencing mitochondrial morphology, because an N-terminally truncated version of the kinase that does not localize to mitochondria does not affect the mitochondrial network. We identify a cryptic mitochondrial targeting sequence in the AURKA N-terminus and discuss how alternative conformations of the protein may influence its cytoplasmic fate.
Correlations between SIRT1 gene polymorphisms and diabetic kidney disease
Authors: Yue Xin-Ge , Yang Zai-Gang , Zhang Yue , Qin Gui-Jun , Liu Fei
Published: June 2018

To investigate the correlations between SIRT1 gene polymorphisms and diabetic kidney disease (DKD). There were 150 patients with DKD in the observation group (urinary albumin excretion rate (UAER) ≥ 300 mg 24 h
−1
), and 160 patients with a more than 10 year history of type 2 diabetes but without retinopathy and DKD (UAER < 30 mg 24 h
−1
) in the control group. Genotypes of three tagged single-nucleotide polymorphism loci (rs3818292, rs4746720 and rs10823108) in the SIRT1 gene in the two groups were detected. Risks of DKD for patients with the GG and GG + AG genotype in the rs10823108 locus of the SIRT1 gene were 2.96 and 2.92 times higher than that for AA genotype carriers, respectively. The risk of DKD for patients with the GG genotype in the rs3818292 locus was 0.23 times and 0.21 times higher than that for AA and for AA + AG genotype carriers, respectively, and the risk of DKD for patients with allele G was 0.66 times higher than that for allele A carriers. There was no significant difference in genotype frequency of rs4746720 locus gene polymorphisms between the observation and control groups. The SIRT1 gene is a genetic susceptibility gene of DKD. Mutation genotype GG and GG + AG in the rs10823108 locus can increase the risk of DKD. Mutation genotype GG and allele G in the rs3818292 locus can decrease the risk of DKD.
The regio-selective synthesis of 10-hydroxy camptothecin norcantharidin conjugates and their biological activity evaluation
in vitro
Authors: Zhao Chang K. , Li Chan , Wang Xian H. , Bao Yu J. , Yang Fu H. , Huang Mei
Published: June 2018

A series of conjugates of 10-hydroxy camptothecin (HCPT) with functionalized norcantharidin derivatives were regio-selectively synthesized in the condition of (3-dimethylaminopropyl) ethyl-carbodiimide monohydrochloride in a moderate yield. The synthesized conjugate HCPT pro-drugs can also suppress cancer cell growth
in vitro
. These conjugated pro-drug constructs possess therapeutic potential as novel bi-functional conjugate platforms for cancer treatment.
Differential loss of components of traditional ecological knowledge following a primate extinction event
Authors: Turvey Samuel T. , Bryant Jessica V. , McClune Katherine A.
Published: June 2018

Traditional ecological knowledge (TEK), an important component of the modern conservation toolkit, is being eroded in indigenous communities around the world. However, the dynamics of TEK loss in response to ecosystem change and disruption to social–ecological systems, and patterns of variation in vulnerability and resilience of different components of TEK, remain poorly understood. The Hainan gibbon (Nomascus hainanus), a culturally significant primate, was formerly distributed across Hainan Island, China, but became extinct across most of this range within living memory and is now restricted to a single landscape, Bawangling National Nature Reserve. Gibbon-specific TEK (including folktales, natural history information and methods of gibbon exploitation) is still present in indigenous communities across seven Hainanese landscapes, but statistically significant differences in TEK content exist between landscapes with different histories of gibbon persistence: respondents from Bawangling and most landscapes that have recently lost gibbons report more gibbon-related folktales compared with landscapes from which gibbons have been absent for several decades. Species-specific folktales might have been lost more rapidly compared with other components of TEK because older community members are typically the ‘cultural repositories’ of stories, whereas knowledge about practical interactions with biodiversity might be shared more widely with younger community members.
Base-catalysed decomposition of polychlorinated biphenyls in transformer oils by mixture of sodium hydroxide, glycerol and iron
Authors: Akhondi Milad , Dadkhah Ali A.
Published: June 2018

In this research, a method based on base-catalysed decomposition (BCD) was developed using sodium hydroxide and glycerol for dechlorination of transformer oils with low levels of polychlorinated biphenyls (PCBs). PCB removal and dechlorination efficiencies were measured by gas chromatography and the silver nitrate titration method, respectively. PCB dechlorination and removal efficiencies after 4 h at 250°C and in the presence of iron were 97.4% and 99.8%, respectively. However, in the absence of iron the same efficiencies were calculated to be 79.4 and 99.7%, respectively. The dielectric loss factor of oil refined at 250°C was 0.0064 and did not meet the required standards to be reused in the transformers. However, that refined at 200°C satisfied the standards with acceptable conversion rates. Use of iron, besides increasing conversion rates, changed the mechanism of the reaction from nucleophilic substitution to a combination of hydrodechlorination and nucleophilic substitution. In the presence of iron, highly chlorinated PCBs were converted to less chlorinated PCBs, and this caused the concentration of less chlorinated PCBs to reach a peak and then decline thereafter. The production of PCB 36 confirmed this. However, in the absence of iron particles, all changes in the PCB concentration curves were downward.
Wake-induced oscillation behaviour of twin bundle conductor transmission lines
Authors: Wu Chuan , Yan Bo , Huang Guizao , Zhang Bo , Lv Zhongbin , Li Qing
Published: June 2018

A numerical method to simulate air flow around a bundle conductor line by means of the FLUENT software is presented and verified by a wind tunnel test for aerodynamic characteristics of a twin bundle conductor line. The lift and drag coefficients of the leeward sub-conductor of a twin bundle conductor varying with its relative position in the wake zone to the windward one under different wind velocities are numerically determined by the presented method. A user-defined subroutine of ABAQUS software is developed to apply the aerodynamic loads on each sub-conductor and the electromagnetic force between sub-conductors. The numerical simulation method for wake-induced oscillation of a bundle conductor line is proposed. By means of the numerical method, wake-induced oscillation processes of twin bundle conductor transmission lines under different parameters, including current intensity, spacer layout, span length and wind velocity, are numerically simulated. Moreover, the effects of those parameters on the oscillation characteristics of the lines, such as vibration mode, frequency, amplitude and motion trace, are discussed. The results obtained provide a fundamental basis for the understanding of wake-induced oscillation behaviour of twin bundle conductor transmission lines and the development of control technique for wake-induced oscillation.
Climate structuring ofBatrachochytrium dendrobatidisinfection in the threatened amphibians of the northern Western Ghats, India
Authors: Thorpe Christopher J. , Lewis Todd R. , Fisher Matthew C. , Wierzbicki Claudia J. , Kulkarni Siddharth , Pryce David , Davies Lewis , Watve Aparna , Knight Mairi E.
Published: June 2018

Batrachochytrium dendrobatidis(Bd) is a pathogen killing amphibians worldwide. Its impact across much of Asia is poorly characterized. This study systematically surveyed amphibians forBdacross rocky plateaus in the northern section of the Western Ghats biodiversity hotspot, India, including the first surveys of the plateaus in the coastal region. These ecosystems offer an epidemiological model system since they are characterized by differing levels of connectivity, edaphic and climatic conditions, and anthropogenic stressors. One hundred and eighteen individuals of 21 species of Anura and Apoda on 13 plateaus ranging from 67 to 1179 m above sea level and 15.89 to 17.92° North latitude were sampled. Using qPCR protocols, 79% of species and 27% of individuals tested were positive forBd. This is the first record ofBdin caecilians in India, the Critically EndangeredXanthophryne tigerinaand EndangeredFejervarya cf. sahyadris. Mean site prevalence was 28.15%. Prevalence below the escarpment was 31.2% and 25.4% above. The intensity of infection (GE) showed the reverse pattern. Infection may be related to elevational temperature changes, thermal exclusion, inter-site connectivity and anthropogenic disturbance. Coastal plateaus may be thermal refuges fromBd. Infected amphibians represented a wide range of ecological traits posing interesting questions about transmission routes.
A multi-functional chemosensor for highly selective ratiometric fluorescent detection of silver(I) ion and dual turn-on fluorescent and colorimetric detection of sulfide
Authors: Kang Ji Hye , Chae Ju Byeong , Kim Cheal
Published: June 2018

A multi-functional chemosensor
1
as silver and sulfide detector was synthesized by the combination of octopamine and 4-dimethylaminocinnamaldehyde. Sensor
1
exhibited a ratiometric fluorescence emission for Ag
+
from blue to sky. The binding mode of
1
and Ag
+
turned out to be a 1 : 1 ratio as determined using Job plot and electrospray ionization (ESI) mass spectral analyses. The sensing mechanism of
1
with silver ion was unravelled by
1
H NMR titrations and theoretical calculations. Sensor
1
also discerned sulfide by enhancing fluorescence intensity and changing colour from yellow to colourless in aqueous solution. The sensing properties of
1
toward S
2−
were investigated by using ESI-mass analysis, Job plot and
1
H NMR titrations. Moreover,
1
could be used as a detector for sulfide in a wide pH range.
A periodic Markov model to formalize animal migration on a network
Authors: Kölzsch Andrea , Kleyheeg Erik , Kruckenberg Helmut , Kaatz Michael , Blasius Bernd
Published: June 2018

Regular, long-distance migrations of thousands of animal species have consequences for the ecosystems that they visit, modifying trophic interactions and transporting many non-pathogenic and pathogenic organisms. The spatial structure and dynamic properties of animal migrations and population flyways largely determine those trophic and transport effects, but are yet poorly studied. As a basis, we propose a periodic Markov model on the spatial migration network of breeding, stopover and wintering sites to formally describe the process of animal migration on the population level. From seasonally changing transition rates we derived stable, seasonal densities of animals at the network nodes. We parametrized the model with high-quality GPS and satellite telemetry tracks of white storks (
Ciconia ciconia
) and greater white-fronted geese (
Anser a. albifrons
). Topological and network flow properties of the two derived networks conform to migration properties like seasonally changing connectivity and shared, directed movement. Thus, the model realistically describes the migration movement of complete populations and can become an important tool to study the effects of climate and habitat change and pathogen spread on migratory animals. Furthermore, the property of periodically changing transition rates makes it a new type of complex model and we need to understand its dynamic properties.
Exact eigenstates of a nanometric paraboloidal emitter and field emission quantities
Authors: Chatziafratis A. , Fikioris G. , Xanthakis J. P.
Published: June 2018

The progress in field emission theory from its initial Fowler–Nordheim form is centred on the transmission coefficient. For the supply (of electrons) function one still uses the constant value due to a supply of plane-waves states. However, for emitting tips of apex radius of 1–5 nm this is highly questionable. To address this issue, we have solved the Schrödinger equation in a sharp paraboloidally shaped quantum box. The Schrödinger equation is separable in the rotationally parabolic coordinate system and we hence obtain the exact eigenstates of the system. Significant differences from the usual Cartesian geometry are obtained. (1) Both the normally incident and parallel electron fluxes are functions of the angle to the emitter axis and affect the emission angle. (2) The WKB approximation fails for this system. (3) The eigenfunctions of the nanoemitter form a continuum only in one dimension while complete discretization occurs in the other two directions. (4) The parallel electron velocity vanishes at the apex which may explain the recent spot-size measurements in near-field scanning electron microscopy. (5) Competing effects are found as the tip radius decreases to 1 nm: The electric field increases but the total supply function decreases so that possibly an optimum radius exists.
The nature of Earth's correlation wavefield: late coda of large earthquakes
Authors: Kennett B. L. N. , Pham Thanh-Son
Published: June 2018

The seismic correlation wavefield constructed from the stacked cross-correlograms of the late coda of earthquake signals at stations across the globe provides a wealth of observed pulses as a function of inter-station distance. The interval from 3 to 10 h after the onset of major earthquakes is employed for the period range from 15 to 50 s. The observations can be well matched by synthetic seismograms for a radially stratified Earth. Many of the correlation phases have similar time behaviour to those in the regular wavefield, but others have no correspondence. All such correlation phases can be explained by the interaction of arrivals with a common slowness at the each of the stations being correlated. Using a generalized ray description of the seismic wavefield, the time-distance behaviour of these correlation phases arises from differences in accumulated phase on different propagation paths through the Earth. Distinct arrivals emerge from the correlation field when there are many ways in which combinations of seismic phases can arise with the same difference in propagation legs. The constituents of the late coda are dominated by steeply travelling waves, and in consequence features associated with multiple passages through the whole Earth emerge distinctly, such as high-order multiples of
PKIKP
.
Experiential contributions to social dominance in a rat model of fragile-X syndrome
Authors: Saxena K. , Webster J. , Hallas-Potts A. , Mackenzie R. , Spooner P. A. , Thomson D. , Kind P. , Chatterji S. , Morris R. G. M.
Published: June 2018

Social withdrawal is one phenotypic feature of the monogenic neurodevelopmental disorder fragile-X. Using a ‘knockout' rat model of fragile-X, we examined whether deletion of the
Fmr1
gene that causes this condition would affect the ability to form and express a social hierarchy as measured in a tube test. Male fragile-X ‘knockout' rats living together could successfully form a social dominance hierarchy, but were significantly subordinate to wild-type animals in mixed group cages. Over 10 days of repeated testing, the fragile-X mutant rats gradually showed greater variance and instability of rank during their tube-test encounters. This affected the outcome of future encounters with stranger animals from other cages, with the initial phenotype of wild-type dominance lost to a more complex picture that reflected, regardless of genotype, the prior experience of winning or losing. Our findings offer a novel insight into the complex dynamics of social interactions between laboratory living groups of fragile-X and wild-type rats. Even though this is a monogenic condition, experience has an impact upon future interactions with other animals. Gene/environment interactions should therefore be considered in the development of therapeutics.
The rise of the ruling reptiles and ecosystem recovery from the Permo-Triassic mass extinction
Authors: Ezcurra Martín D. , Butler Richard J.
Published: June 2018

One of the key faunal transitions in Earth history occurred after the Permo-Triassic mass extinction (ca252.2 Ma), when the previously obscure archosauromorphs (which include crocodylians, dinosaurs and birds) become the dominant terrestrial vertebrates. Here, we place all known middle Permian–early Late Triassic archosauromorph species into an explicit phylogenetic context, and quantify biodiversity change through this interval. Our results indicate the following sequence of diversification: a morphologically conservative and globally distributed post-extinction ‘disaster fauna’; a major but cryptic and poorly sampled phylogenetic diversification with significantly elevated evolutionary rates; and a marked increase in species counts, abundance, and disparity contemporaneous with global ecosystem stabilization some 5 million years after the extinction. This multiphase event transformed global ecosystems, with far-reaching consequences for Mesozoic and modern faunas.
Social contact patterns can buffer costs of forgetting in the evolution of cooperation
Authors: Stevens Jeffrey R. , Woike Jan K. , Schooler Lael J. , Lindner Stefan , Pachur Thorsten
Published: June 2018

Analyses of the evolution of cooperation often rely on two simplifying assumptions: (i) individuals interact equally frequently with all social network members and (ii) they accurately remember each partner's past cooperation or defection. Here, we examine how more realistic, skewed patterns of contact—in which individuals interact primarily with only a subset of their network's members—influence cooperation. In addition, we test whether skewed contact patterns can counteract the decrease in cooperation caused by memory errors (i.e. forgetting). Finally, we compare two types of memory error that vary in whether forgotten interactions are replaced with random actions or with actions from previous encounters. We use evolutionary simulations of repeated prisoner's dilemma games that vary agents' contact patterns, forgetting rates and types of memory error. We find that highly skewed contact patterns foster cooperation and also buffer the detrimental effects of forgetting. The type of memory error used also influences cooperation rates. Our findings reveal previously neglected but important roles of contact pattern, type of memory error and the interaction of contact pattern and memory on cooperation. Although cognitive limitations may constrain the evolution of cooperation, social contact patterns can counteract some of these constraints.
On dangerous ground: the evolution of body armour in cordyline lizards
Authors: Broeckhoven Chris , El Adak Yousri , Hui Cang , Van Damme Raoul , Stankowich Theodore
Published: June 2018

Animal body armour is often considered an adaptation that protects prey against predatory attacks, yet comparative studies that link the diversification of these allegedly protective coverings to differential predation risk or pressure are scarce. Here, we examine the evolution of body armour, including spines and osteoderms, in Cordylinae, a radiation of southern African lizards. Using phylogenetic comparative methods, we attempt to identify the ecological and environmental correlates of body armour that may hint at the selective pressures responsible for defensive trait diversification. Our results show that species inhabiting arid environments are more likely to possess elaborated body armour, specifically osteoderms. We did not find any effect of estimated predation pressure or risk on the degree of body armour. These findings suggest that body armour might not necessarily evolve in response to direct interactions with predators, but rather as a result of increased habitat-mediated predation risk. Furthermore, we discuss the possibility that osteoderms might have been shaped by factors unrelated to predation.
Structural stability as a consistent predictor of phenological events
Authors: Song Chuliang , Saavedra Serguei
Published: June 2018

The timing of the first and last seasonal appearance of a species in a community typically follows a pattern that is governed by temporal factors. While it has been shown that changes in the environment are linked to phenological changes, the direction of this link appears elusive and context-dependent. Thus, finding consistent predictors of phenological events is of central importance for a better assessment of expected changes in the temporal dynamics of ecological communities. Here we introduce a measure of structural stability derived from species interaction networks as an estimator of the expected range of environmental conditions compatible with the existence of a community. We test this measure as a predictor of changes in species richness recorded on a daily basis in a high-arctic plant–pollinator community during two spring seasons. We find that our measure of structural stability is the only consistent predictor of changes in species richness among different ecological and environmental variables. Our findings suggest that measures based on the notion of structural stability can synthesize the expected variation of environmental conditions tolerated by a community, and explain more consistently the phenological changes observed in ecological communities.
The gibbon's Achilles tendon revisited: consequences for the evolution of the great apes?
Authors: Aerts Peter , D'Août Kristiaan , Thorpe Susannah , Berillon Gilles , Vereecke Evie
Published: June 2018

The well-developed Achilles tendon in humans is generally interpreted as an adaptation for mechanical energy storage and reuse during cyclic locomotion. All other extant great apes have a short tendon and long-fibred triceps surae, which is thought to be beneficial for locomotion in a complex arboreal habitat as this morphology enables a large range of motion. Surprisingly, highly arboreal gibbons show a more human-like triceps surae with a long Achilles tendon. Evidence for a spring-like function similar to humans is not conclusive. We revisit and integrate our anatomical and biomechanical data to calculate the energy that can be recovered from the recoiling Achilles tendon during ankle plantar flexion in bipedal gibbons. Only 7.5% of the required external positive work in a stride can come from tendon recoil, yet it is delivered at an instant when the whole-body energy level drops. Consequently, an additional similar amount of mechanical energy must simultaneously dissipate elsewhere in the system. Altogether, this challenges the concept of an energy-saving function in the gibbon's Achilles tendon. Cercopithecids, sister group of the apes, also have a human-like triceps surae. Therefore, a well-developed Achilles tendon, present in the last common ‘Cercopithecoidea–Hominoidea’ ancestor, seems plausible. If so, the gibbon's anatomy represents an evolutionary relict (no harm–no benefit), and the large Achilles tendon is not the premised key adaptation in humans (although the spring-like function may have further improved during evolution). Moreover, the triceps surae anatomy of extant non-human great apes must be a convergence, related to muscle control and range of motion. This perspective accords with the suggestions put forward in the literature that the last common hominoid ancestor was not necessarily great ape-like, but might have been more similar to the small-bodied catarrhines.
Individual variation in the compromise between social group membership and exposure to preferred temperatures
Authors: Cooper B. , Adriaenssens B. , Killen S. S.
Published: June 2018

Group living is widespread among animal species, and comes with a number of costs and benefits associated with foraging, predator avoidance and reproduction. It is largely unknown, however, whether individuals sacrifice exposure to their own preferred or optimal environmental conditions so they can remain part of a social group. Here, we demonstrate that individual three-spine sticklebacks vary in the degree to which they forego exposure to their preferred ambient temperature so they can associate with a group of conspecifics. Individual fish varied widely in preferred temperature when tested in isolation. When the same individuals were presented with a choice of a warm or cold thermal regime in the presence of a social group in one of the environments, fish spent more time with the group if it was close to their own individually preferred temperature. When a group was in a relatively cool environment, focal individuals that were more social deviated most strongly from their preferred temperature to associate with the group. Standard and maximum metabolic rate were not related to temperature preference or thermal compromise. However, individuals with a higher standard metabolic rate were less social, and so energetic demand may indirectly influence the environmental costs experienced by group members. The reduced tendency to engage with a social group when there is a large difference between the group temperature and the individual's preferred temperature suggests a role for temperature in group formation and cohesion that is mediated by individual physiology and behaviour. Together, these data highlight exposure to non-preferred temperatures as a potential cost of group membership that probably has important but to date unrecognized implications for metabolic demand, energy allocation, locomotor performance and overall group functioning.
Point-of-care diagnostic assay for the detection of Zika virus using the recombinase polymerase amplification method
Authors: Vasileva Wand Nadina I. , Bonney Laura C. , Watson Robert J. , Graham Victoria , Hewson Roger
Published: June 2018

The sudden and explosive expansion of Zika virus (ZIKV) from the African continent through Oceania and culminating in the outbreak in South America has highlighted the importance of new rapid point-of-care diagnostic tools for the control and prevention of transmission. ZIKV infection has devastating consequences, such as neurological congenital malformations in infants born to infected mothers and Guillain–Barré syndrome in adults. Additionally, its potential for transmission through vector bites, as well as from person to person through blood transfusions and sexual contact, are important considerations for prompt diagnosis. Recombinase polymerase amplification (RPA), an isothermal method, was developed as an alternative field-applicable assay to PCR. Here we report the development of a novel ZIKV real-time reverse transcriptase RPA (RT-RPA) assay capable of detecting a range of different ZIKV strains from a variety of geographical locations. The ZIKV RT-RPA was shown to be highly sensitive, being capable of detecting as few as five copies of target nucleic acid per reaction, and suitable for use with a battery-operated portable device. The ZIKV RT-RPA demonstrated 100 % specificity and 83 % sensitivity in clinical samples. Furthermore, we determined that the ZIKV RT-RPA is a versatile assay that can be applied to crude samples, such as saliva and serum, and can be used as a vector surveillance tool on crude mosquito homogenates. Therefore, the developed ZIKV RT-RPA is a useful diagnostic tool that can be transferred to a resource-limited location, eliminating the need for a specialized and sophisticated laboratory environment and highly trained staff.
Let’s talk about cardiac T1 mapping
Authors: Hafyane Tarik , Karakuzu Agah , Duquette Catherine , Mongeon François-Pierre , Cohen-Adad Julien , Jerosch-Herold Michael , Friedrich Matthias G. , Stikov Nikola
Published: June 2018

Background

Recent reports have shown that T1 mapping sequences agree in phantoms, but exhibit significant differences in vivo. To characterize these differences in the heart, one needs to consider the effects of magnetization transfer (MT) and the T2 relaxation time in the most commonly used cardiac T1 mapping sequences (MOLLI, ShMOLLI and SASHA).

Methods

Six explanted pig hearts were scanned weekly over a period of six weeks on a 3T system with the MOLLI, ShMOLLI, SASHA sequences and an inversion recovery sequence as reference. The T1 bias was computed as the difference between MOLLI, ShMOLLI, SASHA and the reference T1 values. We applied robust correlation statistics to assess the relationships between T1, T2 and MT. All data are publicly available at: http://neuropoly.pub/pigHeartsData.

Results

A systematic T1 bias was present for all sequences, with MOLLI and ShMOLLI underestimating T1 and SASHA slightly overestimating T1 compared to the reference. The correlation of T1 bias with T2 was weak and insignificant. However, MT showed significant associations with T1 bias for all sequences. Our analysis is also available at: http://neuropoly.pub/pigHeartsInteractive.

Conclusion

We investigated cardiac T1 mapping sequences in a setting that allowed us to explore their accuracy and their dependence on T2 and MT effects. The T2 effects were not significant, and could not explain the T1 bias of MOLLI, ShMOLLI, SASHA with respect to the reference. On the other hand, the T1 biases exhibited a strong correlation with MT. We conclude that inaccuracies in cardiac T1 mapping are primarily due to magnetization transfer.
New genetic signals for lung function highlight pathways and pleiotropy, and chronic obstructive pulmonary disease associations across multiple ancestries
Authors: Shrine Nick , Guyatt Anna L , Erzurumluoglu A Mesut , Jackson Victoria E , Hobbs Brian D , Melbourne Carl , Batini Chiara , Fawcett Katherine A , Song Kijoung , Sakornsakolpat Phuwanat , Li Xingnan , Boxall Ruth , Reeve Nicola F , Obeidat Ma’en , Zhao Jing Hua , Wielscher Matthias , Society Scientific Group Understanding , Weiss Stefan , Kentistou Katherine A , Cook James P , Sun Benjamin B , Zhou Jian , Hui Jennie , Karrasch Stefan , Imboden Medea , Harris Sarah E , Marten Jonathan , Enroth Stefan , Kerr Shona M , Surakka Ida , Vitart Veronique , Lehtimäki Terho , Allen Richard J , Bakke Per S , Beaty Terri H , Bleecker Eugene R , Bossé Yohan , Brandsma Corry-Anke , Chen Zhengming , Crapo James D , Danesh John , DeMeo Dawn L , Dudbridge Frank , Ewert Ralf , Gieger Christian , Gulsvik Amund , Hansell Anna L , Hao Ke , Hoffman Josh D , Hokanson John , Homuth Georg , Joshi Peter K , Joubert Philippe , Langenberg Claudia , Li Xuan , Li Liming , Lin Kuang , Lind Lars , Locantore Nick , Luan Jian’an , Mahajan Anubha , Maranville Joseph C , Murray Alison , Nickle David C , Packer Richard , Parker Margaret M , Paynton Megan L , Porteous David , Prokopenko Dmitry , Qiao Dandi , Rawal Rajesh , Runz Heiko , Sayers Ian , Sin Don D , H Smith Blair , Artigas María Soler , Sparrow David , Tal-Singer Ruth , Timmers Paul RHJ , Van den Berge Maarten , Whittaker John C , Woodruff Prescott , M Yerges Armstrong Laura , Troyanskaya Olga G , Raitakari Olli T , Kähönen Mika , Polasek Ozren , Gyllensten Ulf , Rudan Igor , Deary Ian J , Probst-Hensch Nicole M , Schulz Holger , James Alan L , Wilson James F , Stubbe Beate , Zeggini Eleftheria , Jarvelin Marjo-Riitta , Wareham Nick , Silverman Edwin K , Hayward Caroline , Morris Andrew P , Butterworth Adam S , Scott Robert A , Walters Robin G , Meyers Deborah A , Cho Michael H , Strachan David P , Hall Ian P , Tobin Martin D , Wain Louise V
Published: June 2018

Reduced lung function predicts mortality and is key to the diagnosis of COPD. In a genome-wide association study in 400,102 individuals of European ancestry, we define 279 lung function signals, one-half of which are new. In combination these variants strongly predict COPD in deeply-phenotyped patient populations. Furthermore, the combined effect of these variants showed generalisability across smokers and never-smokers, and across ancestral groups. We highlight biological pathways, known and potential drug targets for COPD and, in phenome-wide association studies, autoimmune-related and other pleiotropic effects of lung function associated variants. This new genetic evidence has potential to improve future preventive and therapeutic strategies for COPD.
Amot regulates neuronal dendritic tree through Yap1
Authors: Rojek Katarzyna O. , Krzemień Joanna , Doleżyczek Hubert , Boguszewski Paweł M. , Kaczmarek Leszek , Konopka Witold , Rylski Marcin , Jaworski Jacek , Holmgren Lars , Prószyński Tomasz J.
Published: June 2018

The Amot-Yap1 complex plays a major role in the regulation of cell contact inhibition, cellular polarity and growth. However, the function of Angiomotin (Amot) and Hippo pathway transcription co-activator Yap1 in the central nervous system remains unclear. In this study, we demonstrate that Amot is a critical mediator of dendritic morphogenesis in cultured hippocampal cells and Purkinje cells in the brain. Amot function in developing hippocampal neurons depends on interactions with Yap1, which is also indispensable for dendrite growth and arborization in vitro. Conditional deletion of Amot or Yap1 in neurons leads to impaired morphogenesis of Purkinje cell dendritic trees, decreased cerebellar size, and causes defects in locomotor coordination of mutant animals. Thus, our studies identified Amot and Yap1 as novel regulators of dendritic tree morphogenesis.