bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiative equilibrium estimates of dust temperature and mass in high-redshift galaxies
Authors: Inoue Akio K , Hashimoto Takuya , Chihara Hiroki , Koike Chiyoe
Published: April 2020

The estimation of the temperature and mass of dust in high-redshift galaxies is essential for discussions of the origin of dust in the early Universe. However, this is made difficult by limited sampling of the infrared spectral-energy distribution. Here, we present an algorithm for deriving the temperature and mass of dust in a galaxy, assuming dust to be in radiative equilibrium. We formulate the algorithm for three geometries: a thin spherical shell, a homogeneous sphere and a clumpy sphere. We also discuss the effects of the mass absorption coefficients of dust at ultraviolet and infrared wavelengths, κUV and κIR, respectively. As an example, we apply the algorithm to a normal, dusty star-forming galaxy at z = 7.5, A1689zD1, for which three data points in the dust continuum are available. Using κUV = 5.0 × 104 and $\kappa _{\rm IR}=30(\lambda /100\,\mu{\rm m})^{-\beta }$ cm2 g−1 with β = 2.0, we obtain dust temperatures of 38–70 K and masses of 106.5–7.3 M⊙ for the three geometries considered. We obtain similar temperatures and masses from just a single data point in the dust continuum, suggesting that the algorithm is useful for high-redshift galaxies with limited infrared observations. In the case of the clumpy sphere, the temperature becomes equal to that of the usual modified black-body fit, because an additional parameter describing the clumpiness works as an adjuster. The best-fitting clumpiness parameter is ξcl = 0.1, corresponding to ∼10 per cent of the volume filling factor of the clumps in this high-redshift galaxy if the clump size is ∼10 pc, similar to that of giant molecular clouds in the local Universe.
Mean field dynamo action in shear flows. I: fixed kinetic helicity
Authors: Jingade Naveen , Singh Nishant K
Published: April 2020

We study mean field dynamo action in a background linear shear flow by employing pulsed renewing flows with fixed kinetic helicity and non-zero correlation time (τ). We use plane shearing waves in terms of time-dependent exact solutions to the Navier–Stokes equation as derived by Singh & Sridhar (2017). This allows us to self-consistently include the anisotropic effects of shear on the stochastic flow. We determine the average response tensor governing the evolution of mean magnetic field, and study the properties of its eigenvalues that yield the growth rate (γ) and the cycle period (Pcyc) of the mean magnetic field. Both, γ and the wavenumber corresponding to the fastest growing axisymmetric mode vary non-monotonically with shear rate S when τ is comparable to the eddy turnover time T, in which case, we also find quenching of dynamo when shear becomes too strong. When $\tau /T\sim {\cal O}(1)$, the cycle period (Pcyc) of growing dynamo wave scales with shear as Pcyc ∝ |S|−1 at small shear, and it becomes nearly independent of shear as shear becomes too strong. This asymptotic behaviour at weak and strong shear has implications for magnetic activity cycles of stars in recent observations. Our study thus essentially generalizes the standard αΩ (or α2Ω) dynamo as also the α effect is affected by shear and the modelled random flow has a finite memory.
EnzymeMiner: automated mining of soluble enzymes with diverse structures, catalytic properties and stabilities
Authors: Hon Jiri , Borko Simeon , Stourac Jan , Prokop Zbynek , Zendulka Jaroslav , Bednar David , Martinek Tomas , Damborsky Jiri
Published: April 2020

Millions of protein sequences are being discovered at an incredible pace, representing an inexhaustible source of biocatalysts. Despite genomic databases growing exponentially, classical biochemical characterization techniques are time-demanding, cost-ineffective and low-throughput. Therefore, computational methods are being developed to explore the unmapped sequence space efficiently. Selection of putative enzymes for biochemical characterization based on rational and robust analysis of all available sequences remains an unsolved problem. To address this challenge, we have developed EnzymeMiner—a web server for automated screening and annotation of diverse family members that enables selection of hits for wet-lab experiments. EnzymeMiner prioritizes sequences that are more likely to preserve the catalytic activity and are heterologously expressible in a soluble form in Escherichia coli. The solubility prediction employs the in-house SoluProt predictor developed using machine learning. EnzymeMiner reduces the time devoted to data gathering, multi-step analysis, sequence prioritization and selection from days to hours. The successful use case for the haloalkane dehalogenase family is described in a comprehensive tutorial available on the EnzymeMiner web page. EnzymeMiner is a universal tool applicable to any enzyme family that provides an interactive and easy-to-use web interface freely available at https://loschmidt.chemi.muni.cz/enzymeminer/.
Exposed facet-controlled N2 electroreduction on distinct Pt3Fe nanostructures of nanocubes, nanorods and nanowires
Authors: Tong Wu , Huang Bolong , Wang Pengtang , Shao Qi , Huang Xiaoqing
Published: April 2020

Understanding the correlation between exposed surfaces and performances of controlled nanocatalysts can aid effective strategies to enhance electrocatalysis, but this is as yet unexplored for the nitrogen reduction reaction (NRR). Here, we first report controlled synthesis of well-defined Pt3Fe nanocrystals with tunable morphologies (nanocube, nanorod and nanowire) as ideal model electrocatalysts for investigating the NRR on different exposed facets. The detailed electrocatalytic studies reveal that the Pt3Fe nanocrystals exhibit shape-dependent NRR electrocatalysis. The optimized Pt3Fe nanowires bounded with high-index facets exhibit excellent selectivity (no N2H4 is detected), high activity with NH3 yield of 18.3 μg h−1 mg−1cat (0.52 μg h−1 cm−2ECSA; ECSA: electrochemical active surface area) and Faraday efficiency of 7.3% at −0.05 V versus reversible hydrogen electrode, outperforming the {200} facet-enclosed Pt3Fe nanocubes and {111} facet-enclosed Pt3Fe nanorods. They also show good stability with negligible activity change after five cycles. Density functional theory calculations reveal that, with high-indexed facet engineering, the Fe-3d band is an efficient d-d coupling correlation center for boosting the Pt 5d-electronic exchange and transfer activities towards the NRR.
High-Chern-number and high-temperature quantum Hall effect without Landau levels
Authors: Ge Jun , Liu Yanzhao , Li Jiaheng , Li Hao , Luo Tianchuang , Wu Yang , Xu Yong , Wang Jian
Published: April 2020

The quantum Hall effect (QHE) with quantized Hall resistance of h/νe2 started the research on topological quantum states and laid the foundation of topology in physics. Since then, Haldane proposed the QHE without Landau levels, showing nonzero Chern number |C| = 1, which has been experimentally observed at relatively low temperatures. For emerging physics and low-power-consumption electronics, the key issues are how to increase the working temperature and realize high Chern numbers (C > 1). Here, we report the experimental discovery of high-Chern-number QHE (C = 2) without Landau levels and C = 1 Chern insulator state displaying a nearly quantized Hall resistance plateau above the Néel temperature in MnBi2Te4 devices. Our observations provide a new perspective on topological matter and open new avenues for exploration of exotic topological quantum states and topological phase transitions at higher temperatures.
Treatment of Carotid Ophthalmic Aneurysm With Woven EndoBridge (WEB SL): 2-Dimensional Operative Video
Authors: Recker Matthew J , Rajah Gary B , Tso Michael K , Dossani Rimal H , Levy Elad I
Published: April 2020

Wide-necked cerebral aneurysms often require complex treatment strategies for optimal treatment. As the surgeon's arsenal continues to expand, consideration of all potential applications of available devices is important. The Woven EndoBridge (WEB) device (MicroVention-Terumo, Aliso Viejo, California) capitalizes on flow disruption to promote thrombosis and is Food and Drug Administration (FDA) approved for saccular wide-necked bifurcation aneurysms located at the middle cerebral artery bifurcation, internal carotid artery (ICA) terminus, anterior communicating artery complex, and basilar apex. In this video, we demonstrate an off-label use of the WEB to treat a wide-necked type II
1
ophthalmic artery aneurysm, highlighting the importance of correct device sizing. The patient is a 74-yr-old woman with a family history of aneurysms. Her aneurysm was found incidentally after a minor trauma. Observation and various treatment options were considered. The patient preferred to avoid open surgical intervention and dual antiplatelet therapy. Endoluminal flow diversion for types II and III ophthalmic artery aneurysms has relatively low occlusion rates and a higher incidence of visual field deficits.
1
A WEB device can be an excellent alternative to treat these aneurysms. A biaxial system was used to selectively catheterize the supraclinoid internal carotid artery and then the aneurysm, and optimal flow diversion was achieved. The patient did well and was discharged home the next day on aspirin alone. Six-month angiography showed near-occlusion of the aneurysm and ophthalmic artery patency. The neck remnant will be followed up with repeat angiography in 6 mo.

The patient gave informed consent for the procedure and video recording. Institutional review board approval was deemed unnecessary.

Video ©University at Buffalo Neurosurgery, 2019. With permission.
Value of the Petromeatal Angle in Predicting Outcome of Translabyrinthine Resection of Vestibular Schwannomas
Authors: Noureldine Mohammad Hassan A , Aum David , Piper Keaton , Zavadskiy Gleb , Peto Ivo , Bach Konrad , van Loveren Harry , Agazzi Siviero
Published: April 2020

BACKGROUND

Factors associated with extent of tumor resection (EOR) and facial nerve outcomes include tumor size, anterior extension of the tumor, patient age, and surgical approach.

OBJECTIVE

To check whether preoperative measurement of the petromeatal (PMA), petroclival (PCA), and petrous-petrous (PPA) angles can help in predicting EOR, facial nerve outcome, and cerebrospinal fluid (CSF) leak occurrence in patients undergoing vestibular schwannoma (VS) surgery via the translabyrinthine approach (TLA).

METHODS

A total of 75 patients were included in this retrospective study. Preoperative magnetic resonance imaging constructive interface in steady state and postcontrast T1-weighted sequences through the internal acoustic meatus were used to measure the PMA, PCA, and PPA.

RESULTS

There was a statistically significant association between tumor size and EOR; every additional cm in tumor size decreases the odds of gross-total (GTR)/near-total (NTR) resection by 524% (P = .0000355).

After controlling for tumor size, the logistic models revealed a significant effect of the angles on EOR. For example, in a patient with a 2-cm VS, every additional degree in PMA, PCA, and PPA increases the odds of GTR/NTR by 2.3% (P = .0000571), 4.05% (P = .0000397), and 0.37% (P = .0000438), respectively.

After adjusting for tumor size, sex, and age, the effect of PMA on the occurrence of an immediate postoperative facial nerve deficit and CSF leak indicated a trend towards significance (P = .0581 and P = .0568, respectively).

CONCLUSION

More obtuse petrous bone angles, namely PMA, PCA, and PPA, are good predictors of GTR or NTR in patients undergoing VS surgery via TLA and may be associated with better facial nerve outcomes and lower CSF leak occurrences.
Recycling resources: silica of diatom frustules as a source for spicule building in Antarctic siliceous demosponges
Authors: Riesgo Ana , Taboada Sergi , Kenny Nathan J , Santodomingo Nadia , Moles Juan , Leiva Carlos , Cox Eileen , Avila Conxita , Cardona Luis , Maldonado Manuel
Published: April 2020

Dissolved silicon (DSi) is biologically processed to produce siliceous skeletons by a variety of organisms including radiolarians, silicoflagellates, choanoflagellates, plants, diatoms and some animals. In the photic ocean, diatoms are dominant consumers over competing other silicifiers. In Antarctica, where DSi is not particularly limiting, diatoms and sponges coexist in high abundances. Interestingly, diatom ingestion by sponges is a regular feeding strategy there. Although it was known that the diatom organic nutrients are readily metabolized by the sponges, what happened to the inorganic diatom silica skeleton remained unexplored. Here, we have conducted a multi-analytical approach to investigate the processing of diatom silica and whether it is reconverted into sponge silica. We have documented widespread diatom consumption by several demosponges, identifying storage vesicles for the diatom-derived silica by electron microscopy and microanalysis. Diatom-consuming sponges showed upregulation of silicatein and silicase genes, which in addition to the δ 30Si values of their silica, supports that the sponges are converting the ingested diatom silica into sponge silica without much further Si fractionation. Our multidisciplinary approach suggests that the reutilization of diatom silica by sponges is a common feature among Antarctic sponges, which should be further investigated in other latitudes and in other silicifiers.
Incidence and Risk Factors of Anterior Longitudinal Ligament Rupture After Posterior Corrective Surgery Using Lateral Lumbar Interbody Fusion for Adult Spinal Deformity
Authors: Maruo Keishi , Arizumi Fumihiro , Kusuyama Kazuki , Kishima Kazuya , Tachibana Toshiya
Published: April 2020

Study Design:

A retrospective single-center study.

Objective:

The objective of this study was to assess the incidence of anterior longitudinal ligament rupture (ALLR) and to identify the risk factors for ALLR in patients with adult spinal deformity (ASD).

Summary of Background Data:

Lateral lumbar interbody fusion (LIF) has been widely used for ASD surgery. However, ALLR has been occasionally identified after posterior spinal correction surgery.

Materials and Methods:

The study included 43 consecutive patients (8 male and 35 female patients) who underwent posterior corrective surgery involving LIF (128 levels) for ASD between 2014 and 2018. The mean age was 72±7 years (range: 62–81 y), and the minimum follow-up period was 1 year [mean: 34±15 mo (range: 12–58 mo)]. Posterior correction and fusion surgery using the cantilever technique was performed following LIF. Oblique LIF was performed in 27 patients, and extreme lateral interbody fusion (XLIF) was performed in 16 patients. The mean number of spinal fused levels was 8.9±1.8 levels (range: 8–15), and the mean number of LIF levels was 3±0.6 levels (range: 2–4). ALLR was considered if a LIF cage showed no contact with the vertebral endplates. The radiographic parameters were thoracic kyphosis, lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt, and sagittal vertical axis.

Results:

ALLR occurred in 10 patients (22%) and at 11 levels (8.6%). XLIF and preexisting osteoporotic vertebral fracture were identified as independent risk factors for ALLR. The change in LL was ∼10 degrees greater in the ALLR group than in the non-ALLR group (P=0.017), and overcorrection was observed in the ALLR group (PI-LL: −7.9±7 degrees). The change in the segmental lordotic angle at the ALLR level was much larger than after LIF and correction surgery. ALLR-related reoperation was performed in 2 cases (decompression surgery owing to posterior impingement and rod breakage).

Conclusions:

ALLR occurred in 10 patients (22%). XLIF and preexisting osteoporotic vertebral fracture were independent risk factors for ALLR. Overcorrection was observed in patients with ALLR.
BMI Does Not Affect Complications or Patient Reported Outcomes After Lumbar Decompression Surgery
Authors: Divi Srikanth N. , Goyal Dhruv K.C. , Stull Justin D. , Kothari Parth , Padua Fortunato G. , Patel Parthik D. , Bowles Daniel R. , Reyes Ariana A. , Galetta Matthew S. , Kaye Ian D. , Kurd Mark F. , Woods Barrett I. , Radcliff Kris E. , Rihn Jeffrey A. , Anderson David G. , Hilibrand Alan S. , Kepler Christopher K. , Vaccaro Alexander R. , Schroeder Gregory D.
Published: April 2020

Study Design:

This is a retrospective comparative review.

Objective:

The objective of this study was to identify the influence of body mass index (BMI) on postsurgical complications and patient reported outcomes measures (PROMs) following lumbar decompression surgery.

Summary of Background Data:

Current literature does not accurately identify the impact of BMI on postsurgical complications or outcomes.

Materials and Methods:

Records from a single-center, academic hospital were used to identify patients undergoing 1 to 3-level lumbar decompression surgery. Patients under 18 years of age, those undergoing surgery for infection, trauma, tumor, or revision, and those with <1-year follow-up were excluded. Patients were split into groups based on preoperative BMI: class I: BMI <25.0 kg/m2; class II: BMI 25.0–29.9 kg/m2; class III: BMI 30.0–34.9 kg/m2; and class IV: BMI >35.0 kg/m2. Absolute PROM scores, the recovery ratio and the percent of patients achieving minimum clinically important difference between groups were compared and a multiple linear regression analysis was performed.

Results:

A total of 195 patients were included with 34 (17.4%) patients in group I, 80 (41.0%) in group II, 49 (25.1%) in group III, and 32 (16.5%) in group IV. Average age was 60.0 (58.0, 62.0) years and average follow-up was 13.0 (12.6, 13.4) months. All patients improved significantly within each group, except for class III and class IV patients, who did not demonstrate significant improvements in terms of Mental Component Score (MCS-12) scores (P=0.546 and 0.702, respectively). There were no significant differences between BMI groups for baseline or postoperative PROM values, recovery ratio, or the percent of patients reaching minimum clinically important difference. Multiple linear regression analysis revealed that BMI was not a significant predictor for change in outcomes for any measure. The 30-day readmission rate was 6.2% and overall revision rate at final follow-up was 5.1%, with no significant differences between groups.

Conclusion:

This study’s results suggest that BMI may not significantly affect complications or patient outcomes at 1-year in those undergoing lumbar decompression surgery.

Level of Evidence:

Level III.
Anatomic Restoration of the Biceps Brachii Insertion Through a Single Anterior Incision
Authors: Goyal Nitin , Wilson David J. , Wysocki Robert W. , Cohen Mark S. , Fernandez John J.
Published: April 2020

Treatment of distal biceps tendon ruptures with surgical repair has been shown to restore peak elbow flexion and supination strength, as well as minimize fatigue with repetitive activity. The anatomic footprint of the biceps is slightly posterior to the apical prominence of the bicipital tuberosity. Single-incision and double-incision methods for repairing distal biceps tendon ruptures have been described. However, previously described single-incision techniques have been unable to accurately re-establish the anatomic position of the tendinous insertion. We describe our technique of performing an anatomic distal biceps repair using a single anterior incision. The proposed benefits of this technique include the restoration of the anatomic footprint area, insertion site, and consequently the native cam effect of the bicipital tuberosity all through a single incision. From a patient’s perspective, the proposed benefit of this technique includes the restoration of supination strength using a single incision.
Utility of Blood Cultures and Empiric Antibiotics in Febrile Pediatric Hemophilia Patients With Central Venous Access Devices
Authors: Al-Samkari Hanny , Ozonoff Al , Landschaft Assaf , Kimia Rotem , Harper Marvin B. , Croteau Stacy E. , Kimia Amir A.
Published: April 2020

Background

Children with hemophilia frequently require long-term central venous access devices (CVADs) for regular infusion of factor products. Hemophilia patients are not immunocompromised, but the presence and use of CVADs are associated with infections including bacteremia. Currently, the utility of blood cultures in evaluation of the febrile hemophilia patient with an indwelling CVAD is unknown, nor is optimal empiric antibiotic use.

Methods

We performed a retrospective cross-sectional study of febrile immunocompetent hemophilia patients with CVADs presenting to a large academic urban pediatric emergency department from 1995 to 2017. We used a natural language processing electronic search, followed by manual chart review to construct the cohort. We analyzed rate of pathogen recovery from cultures of blood in subgroups of hemophilia patients, the pathogen profile, and the reported pathogen susceptibilities to ceftriaxone.

Results

Natural language processing electronic search identified 181 visits for fever among hemophilia patients with indwelling CVADs of which 147 cases from 44 unique patients met study criteria. Cultures of blood were positive in 56 (38%) of 147 patients (95% confidence interval, 30%–47%). Seventeen different organisms were isolated (10 pathogens and 7 possible pathogens) with Staphylococcus aureus and coagulase-negative Staphylococcus species as the most common. Thirty-four percent of isolates were reported as susceptible to ceftriaxone. Positive blood cultures were more common in cases involving patients with inhibitors (n = 71) versus those without (n = 76), odds ratio, 7.4 (95% confidence interval, 3.5–15.9). This was observed irrespective of hemophilia type.

Conclusions

Febrile immunocompetent hemophilia patients with indwelling CVADs have high rates of bacteremia. Empiric antimicrobial therapy should be targeted to anticipated pathogens and take into consideration local susceptibility patterns for Staphylococcus aureus.
A Human-Derived, Collagen-Rich Hydrogel Augments Wound Healing in a Diabetic Animal Model
Authors: Williams Tokoya , Sotelo Leon Daniel , Kaizawa Yukitoshi , Wang Zhen , Leyden Jacinta , Chang James , Fox Paige M.
Published: April 2020

Background

Application of collagen products to wounds has been shown to improve wound healing. Using a collagen-based hydrogel (cHG) capable of cellular support previously developed by our laboratory, we hypothesize that our hydrogel will increase the speed of wound healing by providing a 3-dimensional framework for cellular support, increasing angiogenesis and cell-proliferation at the wound bed.

Methods

Two, 10-mm excisional wounds were created over the dorsum of 12 male, genetically modified Zucker diabetic rats. Wounds were splinted open to limit healing by wound contracture. One wound was treated with an occlusive dressing (OD), whereas the adjacent wound was treated with an OD plus cHG. Occlusive dressings were changed every other day. Hydrogel was applied on day 2 and every 4 days after until complete wound closure. Rate of wound closure was monitored with digital photography every other day. Wounds were harvested at days 10 and 16 for histological and immunohistochemical analysis.

Results

Wound closure was significantly faster in cHG-treated wounds compared with OD-treated wounds. By day 10, cHG-treated wounds achieved 63% wound closure, compared with 55% wound closure in OD-treated wounds (P < 0.05). By day 16, cHG-treated wounds achieved 84% wound closure, compared with 68% wound closure in OD-treated wounds (P < 0.05).

Histologically, wound depth was not different between the cHG and OD groups on days 10 and 16. However, wound length was significantly less in the cHG group compared with the OD group (P < 0.05) consistent with digital photographic analysis. Immunohistochemical analysis for RECA-1 demonstrated that blood vessel density in the wound bed was 2.3 times higher in the cHG group compared with the OD group (P = 0.01) on day 16. Cell proliferation was 3.8 times higher in the cHG group versus the OD group (P < 0.05) on day 10.

Conclusions

Collagen-based hydrogel–treated wounds demonstrated significantly improved healing compared with control. The thermoresponsive feature of collagen hydrogel and its structural stability at body temperature demonstrate promising clinical potential as a vehicle for the delivery of therapeutic cells to the wound bed.
Taxonomic similarity does not predict necessary sample size for
ex situ
conservation: a comparison among five genera
Authors: Hoban Sean , Callicrate Taylor , Clark John , Deans Susan , Dosmann Michael , Fant Jeremie , Gailing Oliver , Havens Kayri , Hipp Andrew L. , Kadav Priyanka , Kramer Andrea T. , Lobdell Matthew , Magellan Tracy , Meerow Alan W. , Meyer Abby , Pooler Margaret , Sanchez Vanessa , Spence Emma , Thompson Patrick , Toppila Raakel , Walsh Seana , Westwood Murphy , Wood Jordan , Griffith M. Patrick
Published: April 2020

Effectively conserving biodiversity with limited resources requires scientifically informed and efficient strategies. Guidance is particularly needed on how many living plants are necessary to conserve a threshold level of genetic diversity in
ex situ
collections. We investigated this question for 11 taxa across five genera. In this first study analysing and optimizing
ex situ
genetic diversity across multiple genera, we found that the percentage of extant genetic diversity currently conserved varies among taxa from 40% to 95%. Most taxa are well below genetic conservation targets. Resampling datasets showed that ideal collection sizes vary widely even within a genus: one taxon typically required at least 50% more individuals than another (though
Quercus
was an exception). Still, across taxa, the minimum collection size to achieve genetic conservation goals is within one order of magnitude. Current collections are also suboptimal: they could remain the same size yet capture twice the genetic diversity with an improved sampling design. We term this deficiency the ‘genetic conservation gap’. Lastly, we show that minimum collection sizes are influenced by collection priorities regarding the genetic diversity target. In summary, current collections are insufficient (not reaching targets) and suboptimal (not efficiently designed), and we show how improvements can be made.
Spatial and temporal variation in nest temperatures forecasts sex ratio skews in a crocodilian with environmental sex determination
Authors: Bock Samantha L. , Lowers Russell H. , Rainwater Thomas R. , Stolen Eric , Drake John M. , Wilkinson Philip M. , Weiss Stephanie , Back Brenton , Guillette Louis , Parrott Benjamin B.
Published: April 2020

Species displaying temperature-dependent sex determination (TSD) are especially vulnerable to the effects of a rapidly changing global climate due to their profound sensitivity to thermal cues during development. Predicting the consequences of climate change for these species, including skewed offspring sex ratios, depends on understanding how climatic factors interface with features of maternal nesting behaviour to shape the developmental environment. Here, we measure thermal profiles in 86 nests at two geographically distinct sites in the northern and southern regions of the American alligator's (
Alligator mississippiensis
) geographical range, and examine the influence of both climatic factors and maternally driven nest characteristics on nest temperature variation. Changes in daily maximum air temperatures drive annual trends in nest temperatures, while variation in individual nest temperatures is also related to local habitat factors and microclimate characteristics. Without any compensatory nesting behaviours, nest temperatures are projected to increase by 1.6–3.7°C by the year 2100, and these changes are predicted to have dramatic consequences for offspring sex ratios. Exact sex ratio outcomes vary widely depending on site and emission scenario as a function of the unique temperature-by-sex reaction norm exhibited by all crocodilians. By revealing the ecological drivers of nest temperature variation in the American alligator, this study provides important insights into the potential consequences of climate change for crocodilian species, many of which are already threatened by extinction.
Offspring reverse transcriptome responses to maternal deprivation when reared with pathogens in an insect with facultative family life
Authors: Körner Maximilian , Vogelweith Fanny , Libbrecht Romain , Foitzik Susanne , Feldmeyer Barbara , Meunier Joël
Published: April 2020

Offspring of species with facultative family life are able to live with and without parents (i.e. to adjust to extreme changes in their social environment). While these adjustments are well understood on a phenotypic level, their genetic underpinnings remain surprisingly understudied. Investigating gene expression changes in response to parental absence may elucidate the genetic constraints driving evolutionary transitions between solitary and family life. Here, we manipulated maternal presence to observe gene expression changes in the fat body of juvenile European earwigs, an insect with facultative family life. Because parents typically protect offspring against pathogens, expression changes were recorded in pathogen-free and pathogen-exposed environments. We found that manipulating maternal presence changed the expression of 154 genes, including several metabolism and growth-related genes, and that this change depended on pathogen presence. Specifically, localization and cell transporter genes were downregulated in maternal absence without pathogens but upregulated with pathogens. At least one immunity gene (pathogenesis-related protein 5) was affected by pathogen exposure regardless of maternal presence. Overall, our findings explicate how offspring adjust to parental deprivation on a molecular level and reveal that such adjustments heavily depend on pathogens in the environment. This emphasizes the central role of pathogens in family life evolution.
Toxin expression in snake venom evolves rapidly with constant shifts in evolutionary rates
Authors: Barua Agneesh , Mikheyev Alexander S.
Published: April 2020

Key innovations provide ecological opportunity by enabling access to new resources, colonization of new environments, and are associated with adaptive radiation. The most well-known pattern associated with adaptive radiation is an early burst of phenotypic diversification. Venoms facilitate prey capture and are widely believed to be key innovations leading to adaptive radiation. However, few studies have estimated their evolutionary rate dynamics. Here, we test for patterns of adaptive evolution in venom gene expression data from 52 venomous snake species. By identifying shifts in tempo and mode of evolution along with models of phenotypic evolution, we show that snake venom exhibits the macroevolutionary dynamics expected of key innovations. Namely, all toxin families undergo shifts in their rates of evolution, likely in response to changes in adaptive optima. Furthermore, we show that rapid-pulsed evolution modelled as a Lévy process better fits snake venom evolution than conventional early burst or Ornstein–Uhlenbeck models. While our results support the idea of snake venom being a key innovation, the innovation of venom chemistry lacks clear mechanisms that would lead to reproductive isolation and thus adaptive radiation. Therefore, the extent to which venom directly influences the diversification process is still a matter of contention.
COVID-19 containment policies through time may cost more lives at metapopulation level
Authors: Wells Konstans , Lurgi Miguel
Published: April 2020

The rapid and pandemic spread of COVID-19 has led to unprecedented containment policies in response to overloaded health care systems. Disease mitigation strategies require informed decision-making to ensure a balance between the protection of the vulnerable from disease and the maintenance of global economies. We show that temporally restricted containment efforts, that have the potential to flatten epidemic curves, can result in wider disease spread and larger epidemic sizes in metapopulations. Longer-term rewiring of metapopulation networks or the enforcement of feasible long-term measures that decrease disease transmissions appear to be more efficient than temporarily restricted intensive mitigation strategies (e.g. short-term mass quarantine). Our results may inform balanced containment strategies for short-term disease spread mitigation in response to overloaded health care systems and longer-term epidemiological sizes.
The closer to the Europe Union headquarters, the higher risk of COVID-19? Cautions regarding ecological studies of COVID-19
Authors: Li Shuai , Hua Xinyang
Published: April 2020

Several ecological studies of the coronavirus disease 2019 (COVID-19) have reported correlations between group-level aggregated exposures and COVID-19 outcomes. While some studies might be helpful in generating new hypotheses related to COVID-19, results of such type of studies should be interpreted with cautions. To illustrate how ecological studies and results could be biased, we conducted an ecological study of COVID-19 outcomes and the distance to Brussels using European country-level data. We found that, the distance was negatively correlated with COVID-19 outcomes; every 100 km away from Brussels was associated with approximately 6% to 17% reductions (all P<0.01) in COVID-19 cases and deaths in Europe. Without cautions, such results could be interpreted as the closer to the Europe Union headquarters, the higher risk of COVID-19 in Europe. However, these results are more likely to reflect the differences in the timing of and the responding to the outbreak, etc. between European countries, rather than the ‘effect’ of the distance to Brussels itself. Associations observed at the group level have limitations to reflect individual-level associations – the so-called ecological fallacy. Given the public concern over COVID-19, ecological studies should be conducted and interpreted with great cautions, in case the results would be mistakenly understood.
Experimental human pneumococcal colonisation in older adults is feasible and safe, not immunogenic
Authors: Adler Hugh , German Esther L , Mitsi Elena , Nikolaou Elissavet , Pojar Sherin , Hales Caz , Robinson Rachel , Connor Victoria , Hill Helen , Hyder-Wright Angela D , Lazarova Lepa , Lowe Catherine , Smith Emma L , Wheeler India , Zaidi Seher R , Jochems Simon P , Loukov Dessi , Reiné Jesús , Solórzano-Gonzalez Carla , d’Argoeuves Polly de Gorguette , Jones Tessa , Goldblatt David , Chen Tao , Aston Stephen J , French Neil , Collins Andrea M , Gordon Stephen B , Ferreira Daniela M , Rylance Jamie
Published: April 2020

Rationale

Pneumococcal colonisation is key to the pathogenesis of invasive disease, but is also immunogenic in young adults, protecting against re-colonisation. Colonisation is rarely detected in older adults, despite high rates of pneumococcal disease.

Objectives

To establish experimental human pneumococcal colonisation in healthy adults aged 50—84 years, to measure the immune response to pneumococcal challenge, and to assess the protective effect of prior colonisation against autologous strain rechallenge.

Methods

Sixty-four participants were inoculated with Streptococcus pneumoniae (serotype 6B, 80,000CFU in each nostril). Colonisation was determined by bacterial culture of nasal wash, serum anti-6B capsular IgG responses by ELISA, and anti-protein immune responses by multiplex electrochemiluminescence.

Measurements and Main Results

Experimental colonisation was established in 39% of participants (25/64) with no adverse events. Colonisation occurred in 47% (9/19) of participants aged 50—59 compared with 21% (3/14) in those aged ≥70 years. Previous pneumococcal polysaccharide vaccination did not protect against colonisation. Colonisation did not confer serotype-specific immune boosting: GMT (95% CI) 2.7μg/mL (1.9—3.8) pre-challenge versus 3.0 (1.9—4.7) four weeks post-colonisation (p = 0.53). Furthermore, pneumococcal challenge without colonisation led to a drop in specific antibody levels from 2.8μg/mL (2.0—3.9) to 2.2μg/mL (1.6—3.0) post-challenge (p = 0.006). Anti-protein antibody levels increased following successful colonisation. Rechallenge with the same strain after a median of 8.5 months (IQR 6.7—10.1) led to recolonisation in 5/16 (31%).

Conclusions

In older adults, experimental pneumococcal colonisation is feasible and safe, but demonstrates different immunological outcomes compared with younger adults in previous studies.
Significantly Improved COVID-19 Outcomes in Countries with Higher BCG Vaccination Coverage: A Multivariable Analysis
Authors: Klinger Danielle , Blass Ido , Rappoport Nadav , Linial Michal
Published: April 2020

COVID-19 has spread to 210 countries within 3 months. We tested the hypothesis that the vaccination with BCG correlates with a better outcome for COVID-19 patients. Our analysis covers 55 countries, complying with predetermined thresholds on population size and deaths per million (DPM). We found a strong negative correlation between the years of BCG administration and a lower DPM along with the pandemic progression in time. The results from multivariable regression tests with 22 economical, demographic, and health-related quantitative properties for each country substantiate the dominant contribution of BCG administration years to the COVID-19 outcomes. Analyzing countries according to an age-group partition reveals that the strongest correlation is attributed to the coverage in BCG vaccination of the young population and mostly to recent years immunization. We propose that BCG immunization coverage, especially among the most recently vaccinated contributes to attenuation of the spread and severity of the COVID-19 pandemic.

One Sentence Summary

BCG vaccination regimes and COVID-19 outcomes
Towards the next phase: evaluation of serological assays for diagnostics and exposure assessment
Authors: GeurtsvanKessel Corine H. , Okba Nisreen M.A. , Igloi Zsofia , Embregts Carmen W.E. , Laksono Brigitta M. , Leijten Lonneke , Rahamat-Langendoen Janette , van den Akker Johannes P.C. , van Kampen Jeroen J.A. , van der Eijk Annemiek A. , van Binnendijk Rob S. , Haagmans Bart , Koopmans Marion
Published: April 2020

The world is entering a new era of the COVID-19 pandemic in which there is an increasing call for reliable antibody testing. To support decision making on the deployment of serology for either population screening or diagnostics, we present a comprehensive comparison of serological COVID-19 assays. We show that the assay detecting total immunoglobulins against the receptor binding domain of SARS CoV-2, had optimal characteristics for antibody detection in different stages of disease.
Detection and isolation of asymptomatic individuals can make the difference in COVID-19 epidemic management
Authors: Mayorga Lía , García Samartino Clara , Flores Gabriel , Masuelli Sofía , Sanchez María Victoria , Mayorga Luis S. , Sánchez Cristián G.
Published: April 2020

Mathematical modeling of infectious diseases is a powerful tool for the design of management policies and a fundamental part of the arsenal currently deployed to deal with the COVID-19 pandemic. Here we present a compartmental model for the disease that can provide healthcare burden parameters allowing to infer possible containment and suppression strategies, explicitly including asymptomatic individuals. The main conclusion of our work is that efficient and timely detection and isolation of these asymptomatic individuals can have dramatic effects on the effective reproduction number and healthcare burden parameters. This intervention can provide a valuable tool complementary to other non-pharmaceutical interventions to contain the epidemic.
Enacting national social distancing policies corresponds with dramatic reduction in COVID19 infection rates
Authors: McGrail Daniel J. , Dai Jianli , McAndrews Kathleen M. , Kalluri Raghu
Published: April 2020

The outbreak the SARS-CoV-2 (CoV-2) virus has resulted in over 2.5 million cases of COVID19, greatly stressing global healthcare infrastructure. Lacking medical prophylactic measures to combat disease spread, many nations have adopted social distancing policies in order to mitigate transmission of CoV-2. While mathematical models have suggested the efficacy of social distancing to curb the spread of CoV-2, there is a lack of systematic studies to quantify the real-world efficacy of these approaches. Here, we quantify the spread rate of COVID19 before and after national social distancing measures were implemented in 26 nations and compare this to the changes in COVID19 spread rate over equivalent time periods in 27 nations that did not enact social distancing policies. We find that social distancing policies significantly reduced the COVID19 spread rate. Using mixed linear regression models we estimate that social distancing policies reduced the spread of COVID19 by 66%. These data suggest that social distancing policies may be a powerful tool to prevent spread of COVID19 in real-world scenarios.
COVID-19 Growth Rate Decreases with Social Capital
Authors: Varshney Lav R. , Socher Richard
Published: April 2020

Background

Social capital has been associated with many public health variables including mortality, obesity, diabetes, and sexually-transmitted disease rates. However, the relationship of social capital to the spread of infectious disease like COVID-19 is lacking. The COVID-19 pandemic presents an unprecedented threat to global health and economy, for which control strategies have relied on aggressive social distancing. However, an understanding of how social capital is related to changes in human mobility patterns for adherence to social distancing is lacking.

Objective

This study examines the association between state- and county-level social capital indices and community health indices in the United States, and the growth rate of COVID-19 cases. It also examines changes in human mobility.

Methods

Using publicly available state- and county-specific time series data for COVID-19 cases from March 13 to March 31, we used exponential fits to determine growth rate. We obtained publicly available mobility change data, originally measured from GPS-enabled mobile devices. The design was then state- and county-level correlation analysis with social capital and community health indices from the Social Capital Project (United States Senate).

Results

In bivariate linear correlation analyses, we find social capital and community health indices were negatively associated with COVID-19 growth rates at both the state and county levels. The correlation was strongest at the county level for the community health index: a one-unit increase in the county community health index was associated with a decrease in the COVID-19 growth rate exponent by 0.045. In further bivariate correlation analyses, we find that social capital indices were negatively associated with retail/recreation movement and positively associated with residential movement. That is, an increase in social capital is correlated with slower COVID-19 infection spread and more adherence to social distancing protocols.

Conclusion

Our results indicate the potential benefit of incorporating social capital concepts in planning policies to control the spread of COVID-19, e.g. different social distancing requirements in different communities. The results also indicate a need for further research into this potentially causal relationship, including examining interventions to increase social capital, community health, and institutional health.
Several countries in one: a mathematical modeling analysis for COVID-19 in inner Brazil
Authors: de Almeida G.B. , Vilches T.N. , Ferreira C.P. , Fortaleza C.M.C.B.
Published: April 2020

Early 2020 and the world experiences its very first pandemic of globalized era. A novel coronavirus, SARS-Cov-2, is the causative agent of severe pneumonia and rapidly spread through many nations, crashing health systems. In Brazil, the emergence of local epidemics in major metropolitan areas is a concern. In a huge and heterogeneous country, with regional disparities and climate diversity, several factors can modulate the dynamics of COVID-19. What should be the scenario for an inner Brazil and what can we do to control infection transmission in each one of these locations? In this paper, a mathematical model was developed to simulate disease transmission among individuals in several scenarios, differing by the intensity and type of control measures. Mitigation strategies rely on social distancing of all individuals, and detection and isolation of infected ones. The model shows that control effort varies among cities. The social distancing is the most efficient method to control disease transmission but improving detection and isolation of infected individuals can help loosening this mitigation strategy.
Assessing the community risk perception toward COVID-19 outbreak in South Korea: evidence from Google and NAVER relative search volume
Authors: Husnayain Atina , Shim Eunha , Fuad Anis , Su Emily Chia-Yu
Published: April 2020

This study aimed to explore the patterns of community health risk perception of coronavirus disease 2019 (COVID-19) in South Korea using Internet search data. Google and NAVER relative search volume data were collected using COVID-19-related terms in Korean language. Online queries were compared with the number of new COVID-19 cases and tests. Time series trends and Spearman’s rank correlation coefficients showed that the number of COVID-19-related queries in South Korea increased during the local and international events; higher in women, certain age groups; and higher in affected areas, which represented the community health risk perception. Greater correlations were found in mobile searches compared to that of desktop searches, indicating the changing behavior in searching health online information. The use of both Google and NAVER RSV to explore the patterns of community health risk perception could be beneficial for targeting risk communication in several perspectives including time, population characteristics, and location.

Article Summary Line

The use of both Google and NAVER RSV to explore the patterns of community health risk perception toward COVID-19 in South Korea could be beneficial for targeting risk communication in several perspectives including time, population characteristics, and location.
Characterizing COVID-19 case detection utilizing influenza surveillance data in the United States, January-March, 2020
Authors: Sandoval Micaela , Hair Adam , Sharma Shreela , Troisi Catherine
Published: April 2020

COVID-19 reached the US in January, 2020, but state and local case detection efforts varied in timing and scale. We conducted a state-level ecological analysis of COVID-19 epidemiology alongside CDC influenza surveillance data and policy timelines. Our findings show wide variation in COVID-19 case detection and influenza-like-illness activity between states.