bluuebunny/crossref_metadata_2025 huggingface dataset:
Intravenous colistin use for infections due to MDR Gram-negative bacilli in critically ill paediatric patients: a systematic review and meta-analysis
Authors: Karageorgos Spyridon A , Bassiri Hamid , Siakallis George , Miligkos Michael , Tsioutis Constantinos
Published: April 2019

Background

Data are limited regarding the clinical effectiveness and safety of intravenous colistin for treatment of infections due to MDR Gram-negative bacilli (GNB) in paediatric ICUs (PICUs).

Methods

Systematic review of intravenous colistin use in critically ill paediatric patients with MDR-GNB infection in PubMed, Scopus and EMBASE (up to 31 January 2018).

Results

Out of 1181 citations, 7 studies were included on the use of intravenous colistin for 405 patients in PICUs. The majority of patients were diagnosed with lower respiratory tract infections, Acinetobacter baumannii being the predominant pathogen. Colistin dosages ranged between 2.6 and 18 mg/kg/day, with only one case reporting a loading dose. Emergence of colistin resistance during treatment was reported in two cases. Nephrotoxicity and neurotoxicity were reported in 6.1% and 0.5%, respectively, but concomitant medications and severe underlying illness limited our ability to definitively associate use of colistin with nephrotoxicity. Crude mortality was 29.5% (95% CI = 21.7%–38.1%), whereas infection-related mortality was 16.6% (95% CI = 12.2%–21.5%).

Conclusions

While the reported incidence of adverse events related to colistin was low, reported mortality rates for infections due to MDR-GNB in PICUs were notable. In addition to severity of disease and comorbidities, inadequate daily dosage and the absence of a loading dose may have contributed to mortality. As the use of colistin for treatment of MDR-GNB infections increases, it is imperative to understand whether optimal dosing of colistin in paediatric patients differs across different age groups. Thus, future studies to establish the pharmacokinetic properties of colistin in different paediatric settings are warranted.
SlSWEET1a is involved in glucose import to young leaves in tomato plants
Authors: Ho Li-Hsuan , Klemens Patrick A W , Neuhaus H Ekkehard , Ko Han-Yu , Hsieh Shu-Ying , Guo Woei-Jiun
Published: April 2019

Sugar allocation from source to sink (young) leaves, critical for plant development, relies on activities of plasma membrane sugar transporters. However, the key sugar unloading mechanism to sink leaves remains elusive. SWEET transporters mediate sugar efflux into reproductive sinks; therefore, they are promising candidates for sugar unloading during leaf growth. Transcripts of SlSWEET1a, belonging to clade I of the SWEET family, were markedly more abundant than those of all other 30 SlSWEET genes in young leaves of tomatoes. High expression of SlSWEET1a was also detected in reproductive sinks, such as flowers. SlSWEET1a was dominantly expressed in leaf unloading veins, and the green fluorescent protein (GFP) fusion protein was localized to the plasma membrane using Arabidopsis protoplasts, further implicating this carrier in sugar unloading. In addition, yeast growth assays and radiotracer uptake analyses further demonstrated that SlSWEET1a acted as a low-affinity (Km ~100 mM) glucose-specific carrier with a passive diffusion manner. Finally, virus-induced gene silencing of SlSWEET1a expression reduced hexose accumulation to ~50% in young leaves, with a parallel 2-fold increase in mature leaves. Thus, we propose a novel function for SlSWEET1a in the uptake of glucose into unloading cells as part of the sugar unloading mechanism in sink leaves of tomato.
Arthroscopy for Management of Femoroacetabular Impingement Syndrome in the Military Health System: A 10-Year Epidemiological Overview of Cases with 2-year Follow-up
Authors: Rhon Daniel , Schmitz Matthew , Mayhew Rachel , Dry Katie , Greenlee Tina
Published: April 2019

Introduction

With the rapid rise in arthroscopy rates for the management of Femoroacetabular Impingement (FAI) Syndrome, it is important to understand current surgical rates and the impact of these surgeries within the Military Health System (MHS). The purpose of this study was to provide an epidemiological descriptive summary of hip arthroscopy for FAI Syndrome in the MHS and describe perioperative healthcare utilization variables.

Methods

Eligible beneficiaries ages 18–50, undergoing hip arthroscopy with 2-year follow-up after surgery were included. Healthcare utilization data were abstracted from the MHS Data Repository (MDR) from June 2003 to July 2015, and included all visits, costs, procedures, and prescriptions taking place in both military and civilian hospitals worldwide.

Results

1870 patients were included (mean age 32.2 years; 55.5% male). 51.7% of the procedures took place in military versus 48.3% in civilian hospitals. Mean hip-related healthcare costs in the 2-year following surgery were $15,434 per patient. Patients had a median of 3 opioid prescriptions and 72% had a comorbidity present after surgery. Generally, rates of surgery grew annually from 66 cases in 2004 to 422 cases in 2013. Overall complication rates were comparable to other published reports. Procedures in both military and civilian hospitals had the same rates of femoroplasty and labral repairs, however acetabuloplasty procedures occurred at a higher rate in military (18.9%) vs civilian (14.7%) hospitals. Only 58.8% of patients had physical therapy in the year prior to surgery, while 82.7% had it after surgery. Additionally, 50% of patients had received opioid prescriptions in the 1 year prior to surgery, while 38.9% had 3 or greater opioid prescriptions beyond the initial perioperative fill within the 2-year follow-up.

Conclusion

Rates of arthroscopy have grown in the MHS over the last decade. Complication rates are similar to those reported in other populations and settings. Utilization of physical therapy was much more likely after surgery than prior to it. Opioid use was high prior to surgery and many individuals continued to receive opioid prescriptions beyond the initial perioperative period.
The GREATS H β + [O iii] luminosity function and galaxy properties at z ∼ 8: walking the way of JWST
Authors: De Barros S , Oesch P A , Labbé I , Stefanon M , González V , Smit R , Bouwens R J , Illingworth G D
Published: April 2019

The James Webb Space Telescope will allow to spectroscopically study an unprecedented number of galaxies deep into the reionization era, notably by detecting [O iii]λλ4959, 5007, and H β nebular emission lines. To efficiently prepare such observations, we photometrically select a large sample of galaxies at z ∼ 8 and study their rest-frame optical emission lines. Combining data from the GOODS Re-ionization Era wide-Area Treasury from Spitzer (GREATS) survey and from HST we perform spectral energy distribution (SED) fitting, using synthetic SEDs from a large grid of photoionization models. The deep Spitzer/IRAC data combined with our models exploring a large parameter space enables to constrain the [O iii] + H β fluxes and equivalent widths for our sample, as well as the average physical properties of z ∼ 8 galaxies, such as the ionizing photon production efficiency with $\log (\xi _\mathrm{ion}/\mathrm{erg}^{-1}\mathrm{Hz})\ge 25.77$. We find a relatively tight correlation between the [O iii] + H β and UV luminosity, which we use to derive for the first time the [O iii]λλ4959, 5007 + H β luminosity function (LF) at z ∼ 8. The z ∼ 8 [O iii] + H β LF is higher at all luminosities compared to lower redshift, as opposed to the UV LF, due to an increase of the [O iii] + H β luminosity at a given UV luminosity from z ∼ 3 to z ∼ 8. Finally, using the [O iii] + H β LF, we make predictions for JWST/NIRSpec number counts of z ∼ 8 galaxies. We find that the current wide-area extragalactic legacy fields are too shallow to use JWST at maximal efficiency for z ∼ 8 spectroscopy even at 1 h depth and JWST pre-imaging to ≳30 mag will be required.
Temporal correlation between the optical and γ-ray flux variations in the blazar 3C 454.3
Authors: Rajput Bhoomika , Stalin C S , Sahayanathan S , Rakshit Suvendu , Mandal Amit Kumar
Published: April 2019

Blazars show optical and γ-ray flux variations that are generally correlated, although there are exceptions. Here we present anomalous behaviour seen in the blazar 3C 454.3 based on an analysis of quasi-simultaneous data at optical, ultraviolet, X-ray, and γ-ray energies, spanning about 9 yr from 2008 August to 2017 February. We have identified four time intervals (epochs), A, B, D, and E, when the source showed large-amplitude optical flares. In epochs A and B the optical and γ-ray flares are correlated, while in D and E corresponding flares in γ-rays are weak or absent. In epoch B the degree of optical polarization strongly correlates with changes in optical flux during a short-duration optical flare superimposed on one of long duration. In epoch E the optical flux and degree of polarization are anticorrelated during both the rising and declining phases of the optical flare. We carried out broad-band spectral energy distribution (SED) modelling of the source for the flaring epochs A,B, D, and E, and a quiescent epoch, C. Our SED modelling indicates that optical flares with absent or weak corresponding γ-ray flares in epochs D and E could arise from changes in a combination of parameters, such as the bulk Lorentz factor, magnetic field, and electron energy density, or be due to changes in the location of the γ-ray-emitting regions.
Feasibility of Robotic-Assisted Neurovascular Interventions: Initial Experience in Flow Model and Porcine Model
Authors: Britz Gavin W , Tomas Johnny , Lumsden Alan
Published: April 2019

BACKGROUND

Despite advances in robotic-assisted technology for cardiac and peripheral vascular interventions, a robotic-assisted platform for neurovascular intervention is not yet available.

OBJECTIVE

To evaluate the feasibility of the CorPath® GRX robotic-assisted platform (Corindus Inc, Waltham, Massachusetts) for neurovascular interventions through preclinical study.

METHODS

The robotic system was tested for its ability to accurately navigate a variety of common neurovascular devices in an in Vitro flow model and in a live, anesthetized pig, under conditions and following procedures appropriate for clinical intervention. An access catheter was introduced manually at the equivalent of the common carotid artery in both models. Endovascular wires and catheters were navigated through the external and internal carotid artery and posterior cerebral vasculature under robotic assistance, using 0.014 in guidewires, 2.4F/1.7F microcatheters, bare-metal stents, and embolic coils.

RESULTS

All procedures in both the flow and porcine models, including navigation, wiring, and deployment of the stent and coils, were performed successfully with no technical complications. There was no evidence of extravasation, dissection, thrombosis, or other vascular injury when angiography was compared before and after the live-animal procedure.

CONCLUSION

This is the first study to demonstrate that use of a robotic-assisted platform is feasible for intracranial neurovascular intervention. The robotic system was successful at navigating and deploying the small-gauge devices specific to neurovascular procedures. Given the potential benefits of robotic-assisted surgery for the patient and the surgeon, further investigation is warranted for this indication.
Ionization age of iron ejecta in the Galactic Type Ia supernova remnant G306.3−0.9
Authors: Sawada Makoto , Tachibana Katsuhiro , Uchida Hiroyuki , Ito Yuta , Matsumura Hideaki , Bamba Aya , Tsuru Takeshi Go , Tanaka Takaaki
Published: April 2019

We present a 190 ks observation of the Galactic supernova remnant (SNR) G306.3−0.9 with Suzaku. To study ejecta properties of this possible Type Ia SNR, the absolute energy-scale at the Fe-K band was calibrated to a level of uncertainty less than 10 eV by a cross-calibration with the Hitomi microcalorimeter using the Perseus cluster spectra. This enabled us for the first time to determine the ionization state of the Fe Kα line of this SNR accurately. The ionization time-scale (τ) of the Fe ejecta was measured to be log10τ (cm−3 s) $= 10.24\, \pm \, 0.03$, significantly smaller than previous measurements. Marginally detected Kα lines of Cr and Mn have ionization time-scales consistent with that of Fe. The global spectrum was well-fitted with shocked interstellar matter (ISM) and at least two ejecta components with different ionization time-scales for Fe and intermediate mass elements (IME) such as S and Ar. One plausible interpretation of the one-order-of-magnitude shorter time-scale of Fe than that of IME ($\log _{10} \tau = 11.17\, \pm \, 0.07$) is a chemically stratified structure of ejecta. By comparing the X-ray absorption column to the H i distribution decomposed along the line of sight, we refined the distance to ∼20 kpc. The large ISM-to-ejecta shocked mass ratio of ∼100 and dynamical time-scale of ∼6 kyr place the SNR in the late Sedov phase. These properties are consistent with a stratified ejecta structure that has survived the mixing processes expected in an evolved SNR.
Effectiveness of probiotics in infantile colic: A rapid review
Authors: Karkhaneh Mohammad , Fraser Lexa , Jou Hsing , Vohra Sunita
Published: April 2019

Background

Infantile colic (IC) is a troubling condition with limited treatment options for young infants. This rapid review aims to synthesize the evidence for probiotics in the treatment and prevention of IC in healthy term infants.

Methods

We searched in MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews for systematic reviews (SRs), and randomized control trials (RCTs) published between January 1, 2000 and July 11, 2018. Trials were included if they recruited healthy full-term infants who received probiotics for treatment or prevention of colic. The quality of evidence was assessed using GRADE criteria. As supplementary information, the safety of probiotics in infants was searched within the reviewed studies and other recent publications.

Results

We identified four SRs and meta-analyses that included six RCTs, and found an additional three RCTs evaluating probiotics for the treatment of IC. One SR and six RCTs were identified for prevention of IC; four of the RCTs were included in the SR and two were published later. The probiotic Lactobacillus reuteri was used in the majority (five of eight) of treatment trials, and was found to significantly reduce crying in colicky breast-fed infants compared to placebo. Only two of the six prevention trials showed a significant decrease in crying time compared to placebo, although another two trials showed other benefits of probiotics, including reduced use of medications (simethicone and cimetropium bromide) and physician visits. No adverse events were identified in the included studies; other research suggests probiotics are generally safe in healthy children.

Conclusion

This rapid review identified limited but favourable evidence of benefit of using probiotics for the treatment of IC in full-term breast-fed infants. While routine use of probiotics for treating or preventing IC cannot yet be recommended, it can be an option to manage IC.
Effect of Blood Flow Restriction Training on Quadriceps Muscle Strength, Morphology, Physiology, and Knee Biomechanics Before and After Anterior Cruciate Ligament Reconstruction: Protocol for a Randomized Clinical Trial
Authors: Erickson Lauren N , Lucas Kathryn C Hickey , Davis Kylie A , Jacobs Cale A , Thompson Katherine L , Hardy Peter A , Andersen Anders H , Fry Christopher S , Noehren Brian W
Published: April 2019

Background

Despite best practice, quadriceps strength deficits often persist for years after anterior cruciate ligament reconstruction. Blood flow restriction training (BFRT) is a possible new intervention that applies a pressurized cuff to the proximal thigh that partially occludes blood flow as the patient exercises, which enables patients to train at reduced loads. This training is believed to result in the same benefits as if the patients were training under high loads.

Objective

The objective is to evaluate the effect of BFRT on quadriceps strength and knee biomechanics and to identify the potential mechanism(s) of action of BFRT at the cellular and morphological levels of the quadriceps.

Design

This will be a randomized, double-blind, placebo-controlled clinical trial.

Setting

The study will take place at the University of Kentucky and University of Texas Medical Branch.

Participants

Sixty participants between the ages of 15 to 40 years with an ACL tear will be included.

Intervention

Participants will be randomly assigned to (1) physical therapy plus active BFRT (BFRT group) or (2) physical therapy plus placebo BFRT (standard of care group). Presurgical BFRT will involve sessions 3 times per week for 4 weeks, and postsurgical BFRT will involve sessions 3 times per week for 4 to 5 months.

Measurements

The primary outcome measure was quadriceps strength (peak quadriceps torque, rate of torque development). Secondary outcome measures included knee biomechanics (knee extensor moment, knee flexion excursion, knee flexion angle), quadriceps muscle morphology (physiological cross-sectional area, fibrosis), and quadriceps muscle physiology (muscle fiber type, muscle fiber size, muscle pennation angle, satellite cell proliferation, fibrogenic/adipogenic progenitor cells, extracellular matrix composition).

Limitations

Therapists will not be blinded.

Conclusions

The results of this study may contribute to an improved targeted treatment for the protracted quadriceps strength loss associated with anterior cruciate ligament injury and reconstruction.
On torsion-free nilpotent loops
Authors: Mostovoy Jacob , Pérez-Izquierdo José M , Shestakov Ivan P
Published: April 2019

We show that a torsion-free nilpotent loop (that is, a loop nilpotent with respect to the dimension filtration) has a torsion-free nilpotent left multiplication group of, at most, the same class. We also prove that a free loop is residually torsion-free nilpotent and that the same holds for any free commutative loop. Although this last result is much stronger than the usual residual nilpotence of the free loop proved by Higman, it is established, essentially, by the same method.
New insights from female bird song: towards an integrated approach to studying male and female communication roles
Authors: Riebel Katharina , Odom Karan J. , Langmore Naomi E. , Hall Michelle L.
Published: April 2019

Historically, bird song has been regarded as a sex-specific signalling trait; males sing to attract females and females drive the evolution of signal exaggeration by preferring males with ever more complex songs. This view provides no functional role for female song. Historic geographical research biases generalized pronounced sex differences of phylogenetically derived northern temperate zone songbirds to all songbirds. However, we now know that female song is common and that both sexes probably sang in the ancestor of modern songbirds. This calls for research on adaptive explanations and mechanisms regulating female song, and a reassessment of questions and approaches to identify selection pressures driving song elaboration in both sexes and subsequent loss of female song in some clades. In this short review and perspective we highlight newly emerging questions and propose a research framework to investigate female song and song sex differences across species. We encourage experimental tests of mechanism, ontogeny, and function integrated with comparative evolutionary analyses. Moreover, we discuss the wider implications of female bird song research for our understanding of male and female communication roles.
A theory and methodology to quantify knowledge
Authors: Fanelli Daniele
Published: April 2019

This article proposes quantitative answers to meta-scientific questions including ‘how much knowledge is attained by a research field?’, ‘how rapidly is a field making progress?’, ‘what is the expected reproducibility of a result?’, ‘how much knowledge is lost from scientific bias and misconduct?’, ‘what do we mean by soft science?’, and ‘what demarcates a pseudoscience?’. Knowledge is suggested to be a system-specific property measured byK, a quantity determined by how much of the information contained in anexplanandumis compressed by anexplanans, which is composed of an information ‘input’ and a ‘theory/methodology’ conditioning factor. This approach is justified on three grounds: (i)Kis derived from postulating that information is finite and knowledge is information compression; (ii)Kis compatible and convertible to ordinary measures of effect size and algorithmic complexity; (iii)Kis physically interpretable as a measure of entropic efficiency. Moreover, theKfunction has useful properties that support its potential as a measure of knowledge. Examples given to illustrate the possible uses ofKinclude: the knowledge value of proving Fermat’s last theorem; the accuracy of measurements of the mass of the electron; the half life of predictions of solar eclipses; the usefulness of evolutionary models of reproductive skew; the significance of gender differences in personality; the sources of irreproducibility in psychology; the impact of scientific misconduct and questionable research practices; the knowledge value of astrology. Furthermore, measures derived fromKmay complement ordinary meta-analysis and may give rise to a universal classification of sciences and pseudosciences. Simple and memorable mathematical formulae that summarize the theory’s key results may find practical uses in meta-research, philosophy and research policy.
Genetic admixture predicts parasite intensity: evidence for increased hybrid performance in Darwin's tree finches
Authors: Peters Katharina J. , Evans Christine , Aguirre J. David , Kleindorfer Sonia
Published: April 2019

Hybridization can increase adaptive potential when enhanced genetic diversity or novel genetic combinations confer a fitness advantage, such as in the evolution of anti-parasitic mechanisms. Island systems are especially susceptible to invasive parasites due to the lack of defence mechanisms that usually coevolve in long-standing host–parasite relationships. We test if host genetic admixture affects parasite numbers in a novel host–parasite association on the Galápagos Islands. Specifically, we compare the number ofPhilornis downsiin nests with offspring sired by Darwin's small tree finch (Camarhynchus parvulus), Darwin's medium tree finch (C. pauper) and hybrids of these two species. The number ofP. downsidecreased with an increasing genetic admixture of the attending male, and nests of hybrid males had approximately 50% fewer parasites thanC. parvulusnests, and approximately 60% fewer parasites thanC. paupernests. This finding indicates that hybridization in this system could be favoured by selection and reveal a mechanism to combat an invasive parasite.
Maternal effects obscure condition-dependent sex allocation in changing environments
Authors: Edwards A. M. , Cameron E. Z. , Wapstra E. , McEvoy J.
Published: April 2019

Climate change increases environmental fluctuations which thereby impact population demography. Species with temperature-dependent sex determination may experience more extreme sex ratio skews, but this has not been considered in species with chromosomally determined sex. However, anticipatory maternal effects cause lifelong physiological changes impacting sex ratios. Here we show, in mice, that more sons were born to mothers in good condition when their breeding environment matched their gestational environment, consistent with theoretical predictions, but mothers in mismatched environments have no condition–sex ratio relationship. Thus, the predicted effect of condition on sex ratio was obscured by maternal effects when the environment changed. This may explain extreme sex ratio skews in reintroduced or translocated populations, and sex ratio skews may become more common and less predictable with accelerating environmental change.
Pollen from multiple sunflower cultivars and species reduces a common bumblebee gut pathogen
Authors: LoCascio George M. , Aguirre Luis , Irwin Rebecca E. , Adler Lynn S.
Published: April 2019

Pathogens are one of the factors driving pollinator declines. Diet can play an important role in mediating pollinator health and resistance to pathogens. Sunflower pollen (Helianthus annuus) dramatically reduced a gut pathogen (Crithidia bombi) ofBombus impatienspreviously, but the breadth of this effect was unknown. We tested whether pollen from nineH. annuuscultivars, four wildH. annuuspopulations,H. petiolarus, H. argophyllusand twoSolidagospp., reducedCrithidiainB. impatienscompared to mixed wildflower pollen and buckwheat pollen (Fagopyrum esculentum) as controls. We also compared hand- and honeybee-collected pollen (which contains nectar) to assess whether diet effects on pathogens were due to pollen or nectar. AllHelianthusandSolidagopollen reducedCrithidiaby 20–40-fold compared to buckwheat pollen, and all but three taxa reducedCrithidiacompared to wildflower pollen. We found no consistent differences between hand- and bee-collected pollen, suggesting that pollen alone can reduceCrithidiainfection. Our results indicate an important role of pollen diet for bee health and potentially broad options within the Asteraceae for pollinator plantings to manage bee disease.
Shaded tangles for the design and verification of quantum circuits
Authors: Reutter David J. , Vicary Jamie
Published: April 2019

We give a scheme for interpreting shaded tangles as quantum circuits, with the property that if two shaded tangles are ambient isotopic, their corresponding computational effects are identical. We analyse 11 known quantum procedures in this way—including entanglement manipulation, error correction and teleportation—and in each case present a fully topological formal verification, yielding generalized procedures in some cases. We also use our methods to identify two new procedures, for topological state transfer and quantum error correction. Our formalism yields in some cases significant new insight into how the procedures work, including a description of quantum entanglement arising from topological entanglement of strands, and a description of quantum error correction where errors are ‘trapped by bubbles’ and removed from the shaded tangle.
Exact solution to a Liouville equation with Stuart vortex distribution on the surface of a torus
Authors: Sakajo Takashi
Published: April 2019

A steady solution of the incompressible Euler equation on a toroidal surface

T

R
,
r

of major radius
R
and minor radius
r
is provided. Its streamfunction is represented by an exact solution to the modified Liouville equation,

∇

T

R
,
r

2

ψ
=
c
 

e

d
ψ

+
(

8

/

d

)
κ

, where

∇

T

R
,
r

2

and
κ
denote the Laplace–Beltrami operator and the Gauss curvature of the toroidal surface respectively, and
c
,
d
are real parameters with
cd
 < 0. This is a generalization of the flows with smooth vorticity distributions owing to Stuart (Stuart 1967
J. Fluid Mech.
29
, 417–440. (
doi:10.1017/S0022112067000941
)) in the plane and Crowdy (Crowdy 2004
J. Fluid Mech.
498
, 381–402. (
doi:10.1017/S0022112003007043
)) on the spherical surface. The flow consists of two point vortices at the innermost and the outermost points of the toroidal surface on the same line of a longitude, and a smooth vorticity distribution centred at their antipodal position. Since the surface of a torus has non-constant curvature and a handle structure that are different geometric features from the plane and the spherical surface, we focus on how these geometric properties of the torus affect the topological flow structures along with the change of the aspect ratio
α
 = 
R
/
r
. A comparison with the Stuart vortex on the flat torus is also made.
Common Caribbean corals exhibit highly variable responses to future acidification and warming
Authors: Bove Colleen B. , Ries Justin B. , Davies Sarah W. , Westfield Isaac T. , Umbanhowar James , Castillo Karl D.
Published: April 2019

We conducted a 93-day experiment investigating the independent and combined effects of acidification (280−3300 µatm
p
CO
2
) and warming (28°C and 31°C) on calcification and linear extension rates of four key Caribbean coral species (
Siderastrea siderea
,
Pseudodiploria strigosa
,
Porites astreoides
,
Undaria tenuifolia
) from inshore and offshore reefs on the Belize Mesoamerican Barrier Reef System. All species exhibited nonlinear declines in calcification rate with increasing
p
CO
2
. Warming only reduced calcification in
Ps. strigosa
. Of the species tested, only
S. siderea
maintained positive calcification in the aragonite-undersaturated treatment
.
Temperature and
p
CO
2
had no effect on the linear extension of
S. siderea
and
Po. astreoides,
and natal reef environment did not impact any parameter examined. Results suggest that
S. siderea
is the most resilient of these corals to warming and acidification owing to its ability to maintain positive calcification in all treatments,
Ps. strigosa
and
U. tenuifolia
are the least resilient, and
Po. astreoides
falls in the middle. These results highlight the diversity of calcification responses of Caribbean corals to projected global change.
Genomics overrules mitochondrial DNA, siding with morphology on a controversial case of species delimitation
Authors: Pedraza-Marrón Carmen del R. , Silva Raimundo , Deeds Jonathan , Van Belleghem Steven M. , Mastretta-Yanes Alicia , Domínguez-Domínguez Omar , Rivero-Vega Rafael A. , Lutackas Loretta , Murie Debra , Parkyn Daryl , Bullock Lewis H. , Foss Kristin , Ortiz-Zuazaga Humberto , Narváez-Barandica Juan , Acero Arturo , Gomes Grazielle , Betancur-R Ricardo
Published: April 2019

Species delimitation is a major quest in biology and is essential for adequate management of the organismal diversity. A challenging example comprises the fish species of red snappers in the Western Atlantic. Red snappers have been traditionally recognized as two separate species based on morphology:
Lutjanus campechanus
(northern red snapper) and
L. purpureus
(southern red snapper). Recent genetic studies using mitochondrial markers, however, failed to delineate these nominal species, leading to the current lumping of the northern and southern populations into a single species (
L. campechanus
). This decision carries broad implications for conservation and management as red snappers have been commercially over-exploited across the Western Atlantic and are currently listed as vulnerable. To address this conflict, we examine genome-wide data collected throughout the range of the two species. Population genomics, phylogenetic and coalescent analyses favour the existence of two independent evolutionary lineages, a result that confirms the morphology-based delimitation scenario in agreement with conventional taxonomy. Despite finding evidence of introgression in geographically neighbouring populations in northern South America, our genomic analyses strongly support isolation and differentiation of these species, suggesting that the northern and southern red snappers should be treated as distinct taxonomic entities.
The population density of an urban raptor is inextricably tied to human cultural practices
Authors: Kumar Nishant , Gupta Urvi , Malhotra Harsha , Jhala Yadvendradev V. , Qureshi Qamar , Gosler Andrew G. , Sergio Fabrizio
Published: April 2019

Human socio-cultural factors are recognized as fundamental drivers of urban ecological processes, but their effect on wildlife is still poorly known. In particular, human cultural aspects may differ substantially between the extensively studied urban settings of temperate regions and the poorly studied cities of the tropics, which may offer profoundly different niches for urban wildlife. Here, we report how the population levels of a scavenging raptor which breeds in the megacity of Delhi, the black kiteMilvus migrans, depend on spatial variation in human subsidies, mainly in the form of philanthropic offerings of meat given for religious purposes. This tight connection with human culture, which generated the largest raptor concentration in the world, was modulated further by breeding-site availability. The latter constrained the level of resource-tracking by the kites and their potential ecosystem service, and could be used as a density-management tool. Similar ties between animal population densities, key anthropogenic resources and human beliefs may occur in thousands of cities all over the globe and may fit poorly with our current understanding of urban ecosystem functioning. For many urban animals, key resources are inextricably linked with human culture, an aspect that has been largely overlooked.
Spatial reciprocity in the evolution of cooperation
Authors: Su Qi , Li Aming , Wang Long , Eugene Stanley H.
Published: April 2019

Cooperation is key to the survival of all biological systems. The spatial structure of a system constrains who interacts with whom (interaction partner) and who acquires new traits from whom (role model). Understanding when and to what degree a spatial structure affects the evolution of cooperation is an important and challenging topic. Here, we provide an analytical formula to predict when natural selection favours cooperation where the effects of a spatial structure are described by a single parameter. We find that a spatial structure promotes cooperation (spatial reciprocity) when interaction partners overlap role models. When they do not, spatial structure inhibits cooperation even without cooperation dilemmas. Furthermore, a spatial structure in which individuals interact with their role models more often shows stronger reciprocity. Thus, imitating individuals with frequent interactions facilitates cooperation. Our findings are applicable to both pairwise and group interactions and show that strong social ties might hinder, while asymmetric spatial structures for interaction and trait dispersal could promote cooperation.
Joint attention skills in wild Arabian babblers (
Turdoides squamiceps
): a consequence of cooperative breeding?
Authors: Ben Mocha Yitzchak , Mundry Roger , Pika Simone
Published: April 2019

Human cooperation strongly relies on the ability of interlocutors to coordinate each other's attentional state: joint attention. One predominant hypothesis postulates that this hallmark of the unique cognitive system of humans evolved due to the combination of an ape-like cognitive system and the prosocial motives that facilitate cooperative breeding. Here, we tested this hypothesis by investigating communicative interactions of a cooperatively breeding bird species, the Arabian babbler (
Turdoides squamiceps
). The behaviour of 12 wild social groups was observed focusing on two distinct communicative behaviours:
object presentation
and
babbler walk
. The results showed that both behaviours fulfilled the criteria for first-order intentional communication and involved co-orientation of recipients' attention. In turn, recipients responded with cooperative and communicative acts that resulted in coordinated joint travel between interlocutors. These findings provide the first evidence that another animal species shows several key criteria traditionally used to infer joint attention in prelinguistic human infants. Furthermore, they emphasize the influence of cooperative breeding on sophisticated socio-cognitive performances, while questioning the necessity of an ape-like cognitive system underlying joint attentional behaviour.
Nocturnal flight-calling behaviour predicts vulnerability to artificial light in migratory birds
Authors: Winger Benjamin M. , Weeks Brian C. , Farnsworth Andrew , Jones Andrew W. , Hennen Mary , Willard David E.
Published: April 2019

Understanding interactions between biota and the built environment is increasingly important as human modification of the landscape expands in extent and intensity. For migratory birds, collisions with lighted structures are a major cause of mortality, but the mechanisms behind these collisions are poorly understood. Using 40 years of collision records of passerine birds, we investigated the importance of species' behavioural ecologies in predicting rates of building collisions during nocturnal migration through Chicago, IL and Cleveland, OH, USA. We found that the use of nocturnal flight calls is an important predictor of collision risk in nocturnally migrating passerine birds. Species that produce flight calls during nocturnal migration tended to collide with buildings more than expected given their local abundance, whereas those that do not use such communication collided much less frequently. Our results suggest that a stronger attraction response to artificial light at night in species that produce flight calls may mediate these differences in collision rates. Nocturnal flight calls probably evolved to facilitate collective decision-making during navigation, but this same social behaviour may now exacerbate vulnerability to a widespread anthropogenic disturbance. Our results also suggest that social behaviour during migration may reflect poorly understood differences in navigational mechanisms across lineages of birds.
Autochthonous faecal virome transplantation (FVT) reshapes the murine microbiome after antibiotic perturbation
Authors: Draper Lorraine A. , Ryan Feargal J. , Dalmasso Marion , Casey Pat G. , McCann Angela , Velayudhan Vimalkumar , Ross R. Paul , Hill Colin
Published: April 2019

Background

It has become increasingly apparent that establishing and maintaining a complex and diverse gut microbiome is fundamental to human health. There are growing efforts to identify methods that can modulate and influence the microbiome, especially in individuals who due to disease or circumstance have experienced a disruption in their native microbiome. Faecal microbial transplantation (FMT) is one method that restores diversity to the microbiome of an individual by introducing microbes from a healthy donor. FMT introduces a complete microbiome into the recipient, including the bacteriome, archaeome, mycome and virome. In this study we investigated whether transplanting an autochthonous faecal virome consisting primarily of bacteriophages could impact a bacteriome disrupted by antibiotic treatment (FaecalViromeTransplantation;FVT).

Results

Following disruption of the bacteriome by penicillin and streptomycin, test mice (n=8) received a bacteria free, faecal transplant, while Control mice (n=8) received a heated and nuclease treated control. The bacteriomes (as determined via 16S rRNA sequencing) of mice that received an FVT, in which bacteriophages predominate, separated from those of the Control mice as determined by principle co-ordinate analysis (PCoA), and contained differentially abundant taxa that reshaped the bacteriome profile such that it more closely resembled that of the pre-treatment mice. Similarly, metagenomic sequencing of the virome confirmed that the bacteriophages present in the gut of treatment and Control mice differed over time in both abundance and diversity, with transplanted phages seen to colonise the FVT mice.

Conclusions

An autochthonous virome transplant impacts on the bacteriome and virome of mice following antibiotic treatment. The virome, consisting mainly of bacteriophages, reshapes the bacteriome such that it more closely resembles the pre-antibiotic state. To date, faecal transplants have largely focussed on transferring living microbes, but given that bacteriophage are inert biological entities incapable of colonising in the absence of a sensitive host they could form a viable alternative that may have fewer safety implications and that could be delivered as a robust formulation.
Territory acquisition mediates the influence of predators and climate on juvenile red squirrel survival
Authors: Hendrix Jack G , Fisher David N , Martinig April Robin , Boutin Stan , Dantzer Ben , Lane Jeffrey E , McAdam Andrew G
Published: April 2019

Juvenile survival to first breeding is a key life history stage. Survival through this period can be particularly challenging when it coincides with harsh environmental conditions like winter climate or food scarcity, and so cohort survival can be highly variable. However, the small size and dispersive nature of juveniles makes studying their survival difficult. In territorial species, a key life history event is the acquisition of a territory. A territory is expected to enhance survival, but how it does so, possibly through mediating mortality, is not often identified. We tested how the timing of territory acquisition influenced the survival of juvenile North American red squirrels Tamiasciurus hudsonicus, hereafter red squirrels, and how the timing of this event mediated sources of mortality. We hypothesized that securing a territory prior to the caching season would reduce juvenile susceptibility to predation or climatic factors over winter. Using 27 years of data on the survival of individually-marked juvenile red squirrels, we tested how the timing of territory acquisition influenced survival, whether the population density of red squirrel predators and mean temperature over winter were related to individual survival probability, and if territory ownership mediated these effects. Juvenile survival was lower in years of high predator abundance and in colder winters. Autumn territory owners were less susceptible to lynx Lynx canadensis, and possibly mustelid Mustela and Martes spp., predation. Autumn territory owners had lower survival in colder winters, while non-owners had higher survival in cold winters. Our results show how the timing of a life history event like territory acquisition can directly affect survival and also mediate the effects of biotic and abiotic factors later in life. This engenders a better understanding of the fitness consequences of the timing of key life history events.
Copy number variant syndromes are frequent in schizophrenia: progressing towards a CNV-schizophrenia model
Authors: Sriretnakumar Venuja , Zai Clement C. , Wasim Syed , Barsanti-Innes Brianna , Kennedy James L. , So Joyce
Published: April 2019

The genetic underpinnings of schizophrenia (SCZ) remain unclear. SCZ genetic studies thus far have only identified numerous single nucleotide polymorphisms with small effect sizes and a handful of copy number variants (CNVs). This study investigates the prevalence of well-characterized CNV syndromes and candidate CNVs within a cohort of 348 SCZ patients, and explores correlations to their phenotypic findings. There was an enrichment of syndromic CNVs in the cohort, as well as brain-related and immune pathway genes within the detected CNVs. SCZ patients with brain-related CNVs had increased CNV burden, neurodevelopmental features, and types of hallucinations. Based on these results, we propose a CNV-SCZ model wherein specific phenotypic profiles should be prioritized for CNV screening within the SCZ patient population.
Interactions between the gut microbiome and host gene regulation in cystic fibrosis
Authors: Dayama Gargi , Priya Sambhawa , Niccum David E. , Khoruts Alexander , Blekhman Ran
Published: April 2019

Cystic Fibrosis (CF) is the most common autosomal recessive genetic disease in Caucasians. It is caused by mutations in theCFTRgene, leading to poor hydration of mucus and impairment of the respiratory, digestive, and reproductive organ functions. Advancements in medical care have lead to markedly increased longevity of patients with CF, but new complications have emerged, such as early onset of colorectal cancer (CRC). Although the pathogenesis of CRC in CF remains unclear, altered host-microbe interactions might play a critical role. Here, we characterize the changes in the gut microbiome and host gene expression in colonic mucosa of CF patients relative to healthy controls. We find that CF patients show decreased microbial diversity, decreased abundance of taxa such asButyricimonas, Sutterella,and Ruminococcaceae, and increased abundance of other taxa, such as Actinobacteria and Firmicutes. We find that 1543 genes, includingCFTR,show differential expression in the colon of CF patients compared to healthy controls. Interestingly, we find that these genes are enriched with functions related to gastrointestinal and colorectal cancer, such as metastasis of CRC, tumor suppression, cellular dysfunction, p53 and mTOR signaling pathways. Lastly, we modeled associations between relative abundances of specific bacterial taxa in the gut mucosa and host gene expression, and identified CRC-related genes, includingLCN2andDUOX2,for which gene expression is correlated with the abundance of CRC-associated bacteria, such as Ruminococcaceae andVeillonella. Our results provide new insight into the role of host-microbe interactions in the etiology of CRC in CF.
Early Hippocampal Sharp-Wave Ripple Deficits Predict Later Learning and Memory Impairments in an Alzheimer’s Disease Mouse Model
Authors: Jones Emily A. , Gillespie Anna K. , Yoon Seo Yeon , Frank Loren M. , Huang Yadong
Published: April 2019

Alzheimer’s disease (AD) is characterized by progressive memory loss, and there is a pressing need to identify early pathophysiological alterations that predict subsequent memory impairment. Hippocampal sharp-wave ripples (SWRs) – electrophysiological signatures of memory reactivation in the hippocampus – are a compelling candidate for doing so. Mouse models of AD show reductions in both SWR abundance and associated slow gamma (SG) power during aging, but these alterations have yet to be directly linked to memory impairments. In aged apolipoprotein E4 knock in (apoE4-KI) mice – a model of the major genetic risk factor for AD – we found that reduced SWR abundance and associated CA3 SG power predicted spatial memory impairments measured 1–2 months later. Importantly, SWR-associated CA3 SG power reduction in young apoE4-KI mice also predicted spatial memory deficits measured 10 months later. These results establish features of SWRs as potential functional biomarkers of memory impairment in AD.
Controllability Governs the Balance Between Pavlovian and Instrumental Action Selection
Authors: Dorfman Hayley M. , Gershman Samuel J.
Published: April 2019

A Pavlovian bias to approach reward-predictive cues and avoid punishment-predictive cues can conflict with instrumentally-optimal actions. While most previous work has assumed that this bias is a fixed trait, we argue that it can vary within an individual. In particular, we propose that the brain arbitrates between Pavlovian and instrumental control by inferring which is a better predictor of reward. The instrumental predictor is more flexible; it can learn values that depend on both stimuli and actions, whereas the Pavlovian predictor learns values that depend only on stimuli. The arbitration theory predicts that the Pavlovian predictor will be favored when rewards are relatively uncontrollable, because the additional flexibility of the instrumental predictor is not useful. Consistent with this hypothesis, we find that the Pavlovian approach bias is stronger under low control compared to high control contexts.