bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-propelling Leidenfrost droplets on a variable topography surface
Authors: Arter James M. , Cleaver David J. , Takashina Kei , Rhead Andrew T.
Published: December 2018

Leidenfrost water droplets can self-propel on heated surfaces with ratcheted topography, a very useful characteristic for systems with excess heat where fluid flow without moving parts is desirable. Reliability and flow rate are significant concerns for such systems. Here, the effect of the surface profile on reliability and droplet velocity are investigated on a single device with a continuously adjustable millimetre-scale ratcheted surface. Conditions are described under which the droplet velocity can exceed 350 mm/s. The reliability of droplet propulsion is shown to be improved for ratchet geometries with an overhang.
Realization of the high-performance THz GaAs homojunction detector below the frequency of Reststrahlen band
Authors: Bai Peng , Zhang Y. H. , Guo X. G. , Fu Z. L. , Cao J. C. , Shen W. Z.
Published: December 2018

High-performance terahertz (THz) detectors are in great need in the applications of security, medicine, as well as in astronomy. A high responsivity p-GaAs homojunction interfacial workfunction internal photoemission (HIWIP) detector was demonstrated for a specific frequency (5 THz) below the frequency of the Reststrahlen band. The experimental results indicate that the optimized detector shows significant enhancement of the response below the Reststrahlen band in contrast to the conventional detectors. With the bottom gold layer serving as a perfect reflector, nearly 50% increment of responsivity and quantum efficiency was obtained further due to the cavity effect. Though very simple, such reflector design shows a satisfactory effect and is easy to be realized in practical applications. The resultant peak responsivity of the detector with a bottom reflector could be as high as 6.8 A/W at 1 V bias. The noise equivalent power is 2.3×10−12W/Hz1/2. Due to the absorption ability to normal incident light and high responsivity, the p-GaAs HIWIP detector is promising for the focal plane array and large-scale pixelless imaging applications.
Horizontal displacement monitoring method of deep foundation pit based on laser image recognition technology
Authors: Liu Peng , Xie Shulin , Zhou Guangyi , Zhang Lixiao , Zhang Guoxian , Zhao Xuefeng
Published: December 2018

Currently, inclinometers are often used to monitor the horizontal displacement of deep foundation pits; however, this method generally has a high cost and complex operation and cannot monitor in real time. In this paper, a novel monitoring method for horizontal displacement of deep foundation pits based on laser image recognition technology is proposed. By identifying the displacement of the spot produced by the laser emitter fixed at the monitoring point, the displacement of the deep foundation pit is determined. In addition, the impact of the angle is considered and eliminated. A series of experimental results indicate that this method exhibits high precision and satisfies the requirements of practical engineering. Simultaneously, it exhibits the advantages of low cost, easy operation, and real-time monitoring. It provides a novel method for the displacement monitoring of deep foundation pits.
Resonance absorption of a broadband laser pulse
Authors: Palastro J. P. , Shaw J. G. , Follett R. K. , Colaïtis A. , Turnbull D. , Maximov A. V. , Goncharov V. N. , Froula D. H.
Published: December 2018

Broad bandwidth, infrared light sources have the potential to revolutionize inertial confinement fusion (ICF) by suppressing laser-plasma instabilities. There is, however, a tradeoff: The broad bandwidth precludes high efficiency conversion from the infrared to the ultraviolet, where laser-plasma interactions are weaker. Operation in the infrared could intensify the role of resonance absorption, an effect long suspected to be the shortcoming of early ICF experiments. Here, we present simulations exploring the effect of the bandwidth on resonance absorption. In the linear regime, the bandwidth has little effect on resonance absorption; in the nonlinear regime, the bandwidth suppresses enhanced absorption resulting from the electromagnetic decay instability. These findings evince that, regardless of the bandwidth, an ICF implosion will confront at least linear levels of resonance absorption.
Metal-insulator transition in V2O3 thin film caused by tip-induced strain
Authors: Alyabyeva N. , Sakai J. , Bavencoffe M. , Wolfman J. , Limelette P. , Funakubo H. , Ruyter A.
Published: December 2018

We have demonstrated pressure-induced transition in a c-axis oriented vanadium sesquioxide (V2O3) thin film from a strongly correlated metal to a Mott insulator in a submicrometric region by inducing a local stress using contact atomic force microscopy. To have an access to a pressure range of sub-gigapascal, a tip with a large radius of 335 nm was prepared by chemical vapour deposition of platinum onto a commercial tip with a focused ion beam (FIB). The FIB-modified tip gives a good electrical contact at low working pressures (0.25–0.4 GPa) allowing unambiguously to evidence reversible metal-insulator transition in a pulsed laser-deposited V2O3 thin film by means of local investigations of current-voltage characteristics. A finite element method has confirmed that the diminution of the c/a ratio under this tip pressure explains the observed phase transition of the electron density of states in the film.
Organic transistor nonvolatile memory with an integrated molecular floating-gate/tunneling layer
Authors: Xu Ting , Guo Shuxu , Xu Meili , Li Shizhang , Xie Wenfa , Wang Wei
Published: December 2018

Floating-gate based organic field-effect transistor (FG-OFET) nonvolatile memories (NVMs) are demonstrated based on an integrated molecular floating-gate/tunneling layer, in which small molecular fullerene (C60) acting as the floating-gate and long-chain alkane molecule tetratetracontane acting as the tunneling layer are synchronously prepared by vacuum thermal evaporation. The effects of the thickness and the component of the integrated floating-gate/tunneling layer on the performances of memory are investigated. As a result, a high performance FG-OFET NVM is achieved, with a large memory window of 8.0 V on average, stable retention capability over 10 years, and reliable switching endurance over 100 cycles at the programming/erasing voltages of ±40 V, at an optimized condition.
Wideband signal transceiver module with a Doppler shift function
Authors: Zeng Hao , Ye Peng , Guo Lianping , Liao Ke
Published: December 2018

The wideband signal transceiver module forms the core component of the radar signal target simulator and the key module in measuring the Doppler shift. In this paper, we present a design for a miniaturized wideband signal transceiver module based on a PXIe bus, with an operating frequency range of 65 MHz–3 GHz, an instantaneous measurement bandwidth of 800 MHz on a standard 3U (where 1U = 4.445 cm) board with three slots. The module adopts a zero intermediate frequency transceiver, and the baseband uses two analog to digital converters, a field programmable gate array, and two digital to analog converters as the core hardware architecture. The module combines key technologies including variable-frequency local oscillator synthesis, radio-frequency broadband signal conditioning, and high-speed high-resolution baseband signal acquisition and generation. This paper describes a novel design for the Doppler shift function. Considering the limited size and volume of the module, Doppler shift technology combining a complex signal and a real signal was adopted to achieve full band coverage with an operating frequency range of 65 MHz–3 GHz. We verified that this module could generate the Doppler shift in the frequency band from −400 Hz to 400 Hz in steps of 2 Hz and with an error of ±2 Hz.
Improved general-purpose five-point model for water: TIP5P/2018
Authors: Khalak Yuriy , Baumeier Björn , Karttunen Mikko
Published: December 2018

A new five point potential for liquid water, TIP5P/2018, is presented along with the techniques used to derive its charges from ab initio per-molecule electrostatic potentials in the liquid phase using the split charge equilibration of Nistor et al. [J. Chem. Phys. 125, 094108 (2006)]. By taking the density and diffusion dependence on temperature as target properties, significant improvements to the behavior of isothermal compressibility were achieved along with improvements to other thermodynamic and rotational properties. While exhibiting a dipole moment close to ab initio values, TIP5P/2018 suffers from a too small quadrupole moment due to the charge assignment procedure and results in an overestimation of the dielectric constant.
Impedance spectroscopy and equivalent circuits of metal-dielectric composites around the percolation threshold
Authors: Gompf Bruno , Dressel Martin , Berrier Audrey
Published: December 2018

Although tunable metal/dielectric nanoparticle composites are promising candidates for a large number of potential applications in electronics, sensor technology, and optical devices, little has been done on their high frequency behavior. Here, we demonstrate that the high frequency response in the kHz to MHz range of Ag-nanoparticles embedded in the highly flexible elastomer PDMS can, on the one hand, be tuned by strain and, on the other hand, be nicely described by common equivalent circuits. Switching on and off the different elements of the equivalent circuit, namely, resistors, constant phase elements, and inductance, the impedance spectra of the composites can be modelled even across the percolation, encompassing both the insulating phase and the metallic state.
Phosphorus-Based α-Amino Acid Mimetic for Enhanced Flame-Retardant Properties in an Epoxy Resin
Authors: Stanfield Melissa K. , Stojcevski Filip , Hendlmeier Andreas , Varley Russell J. , Carrascal Jeronimo , Osorio Andres F. , Eyckens Daniel J. , Henderson Luke C.
Published: December 2018

This work demonstrates the introduction of a phosphonate moiety into a commonly used curing agent, 4,4′-diaminodiphenylmethane (DDM), via an α-aminophosphonate. This compound (DDMP) can be prepared and isolated in analytical purity in under 1 h and in good yield (71 %). Thermoset polymer (epoxy-derived) samples were prepared using a room-temperature standard cure (SC) and a post-cured (PC) protocol to encourage incorporation of the α-aminophosphonate into the polymer network, with improved flammability properties observed for the latter. Thermogravimetric analysis under a nitrogen atmosphere showed increased char yield at 600°C, and similar observations were made when analysis was conducted in air. Significant reductions in flammability are observed at very low phosphorus content (P% = 0.16–0.49 %), demonstrated by higher char yields (25.5 from 14.0 % in air), decreased burn time from ignition (60 to 24 s), and decreased mass loss after ignition (87.6 to 58.5 %). Limiting Oxygen Index for the neat polymer (P% = 0 %, 20.3 ± 0.8 %) increased with increasing α-aminophosphonate additive (P% = 0.16 %, 20.8 ± 0.6 %; P% = 0.32 %, 21.4 ± 0.4 %; P% = 0.49 %, 22.6 ± 0.8 %).
Phylogeny, biogeography and foliar manganese accumulation of Gossia (Myrtaceae)
Authors: McLay Todd , Holmes Gareth D. , Forster Paul I. , Hoebee Susan E. , Fernando Denise R.
Published: December 2018

The rainforest genus Gossia N.Snow & Guymer (Myrtaceae) occurs in Australia, Melanesia and Malesia, and is capable of hyperaccumulating the heavy metal manganese (Mn). Here, we used nuclear ribosomal and plastid spacer DNA-sequence data to reconstruct the phylogeny of 19 Australian species of Gossia and eight New Caledonian taxa. Our results indicated that the relationship between Gossia and Austromyrtus (Nied.) Burret is not fully resolved, and most Australian species were supported as monophyletic. Non-monophyly might be related to incomplete lineage sorting or inaccurate taxonomic classification. Bark type appears to be a morphological synapomorphy separating two groups of species, with more recently derived lineages having smooth and mottled ‘python’ bark. New Caledonian species were well resolved in a single clade, but were not the first diverging Gossia lineage, calling into doubt the results of a recent study that found Zealandia as the ancestral area of tribe Myrteae. Within Australia, the evolution of multiple clades has probably been driven by well-known biogeographic barriers. Some species with more widespread distributions have been able to cross these barriers by having a wide range of soil-substrate tolerances. Novel Mn-hyperaccumulating species were identified, and, although Mn hyperaccumulation was not strongly correlated with phylogenetic position, there appeared to be some difference in accumulation levels among clades. Our study is the first detailed phylogenetic investigation of Gossia and will serve as a reference for future studies seeking to understand the origin and extent of hyperaccumulation within the Myrteae and Myrtaceae more broadly.
Plectranthus laxus and P. wallamanensis (Lamiaceae): new species from tropical Queensland, Australia
Authors: Wilson Trevor C. , Forster Paul I.
Published: December 2018

Two new species of Plectranthus L’Hér. are described from tropical Queensland. Both Plectranthus laxus T.C.Wilson & P.I.Forst. and P. wallamanensis T.C.Wilson & P.I.Forst. are perennial suffrutescent shrubs found in open, exposed rocky habitats in the Wet Tropics bioregion. Both species are illustrated and notes on habitat, distribution, affinities and conservation status are provided. A revised key for Plectranthus in Queensland and the Australian tropics is presented.
Tecomanthe burungu (Bignoniaceae), a new species from northern Queensland
Authors: Zich F. A. , Ford A. J.
Published: December 2018

The new species, Tecomanthe burungu Zich & A.J.Ford (Bignoniaceae) from the Wet Tropics bioregion of north-eastern Queensland is described, illustrated and differentiated from similar and closely related taxa.
Corrosion, oxidation and high-temperature tribological properties of Ti–B–N coatings
Authors: Asempah Isaac , Yu Lihua , Ju Hongbo , Yu Dian , Xu Junhua , Miao Ran
Published: December 2018

Ti–B–N (nc-TiN/ a-BN) composite coatings with various boron contents were deposited by magnetron sputtering. nano-indentation, ball-on-disc dry sliding X-ray diffraction, and, Raman spectroscopy was used in evaluating the compositional, mechanical and tribological properties of these coatings. The corrosion behaviour of the Ti–B–N coatings was assessed by the electrochemical potentiodynamic polarisation method in a 3 mol-% of NaCl solution. The coefficient of friction (CoF) of the coatings initially increased to 1.0 when the test temperature was 200°C, but a further increase in temperature to 700°C resulted in a decrease in the CoF value to ∼0.18 which was due to the presence of Magneli-type Ti nO2 n−1 oxides. In contrast to the CoF, there was a consistent increase in wear rate when the temperature was increased; the highest wear rate was obtained at 700°C. The B incorporated coatings exhibited improvement in both oxidation and corrosion resistance properties.
Case Salience and the Influence of External Constraints on the Supreme Court
Authors: Strother Logan
Published: December 2018

Recent scholarship suggests that Supreme Court decision making is significantly constrained by Congress and the public, often arguing that case salience is a key factor in the operation of these constraints. However, scholars have developed different theoretical expectations regarding the effects of case salience on justices and have found empirical support for mutually contradictory theories. Furthermore, these studies rely on an endogenous measure of case salience. I replicate two leading studies using a theoretically appropriate measure of case salience in order to shed new light on this important topic, finding evidence of constraint from the public in salient cases.
3-Bromopyruvate Attenuates Experimental Pulmonary Hypertension via Inhibition of Glycolysis
Authors: Zhang Yun-Long , Zhang Rui , Shen Yi-Fan , Huang Kai-Yue , He Yang-Yang , Zhao Jun-Han , Jing Zhi-Cheng
Published: December 2018

BACKGROUND

The shift of metabolism from mitochondrial oxidative phosphorylation to glycolysis and mitochondria binding partner of hexokinase are features common to cancer. These have been seen in pulmonary hypertension (PH) as well. An inhibitor of hexokinase 2 (HK 2), the small molecule 3-bromopyruvate (3-BrPA) is an incredibly powerful and swift-acting anticancer agent. However, whether it could be of potential benefit to PH has still been unknown.

METHODS

Sprague–Dawley rats with monocrotaline (MCT)-induced PH were administered 2 oral doses of 3-BrPA (15 and 30 mg/kg/day, respectively) for 14 days. Hemodynamic parameters were obtained by right heart catheterization. Histopathology, immunohistochemistry, transmission electron microscopy, flow cytometry, and assessments of relative protein expressions were conducted.

RESULTS

Compared with MCT treatment, 3-BrPA decreased mean pulmonary arterial pressure and pulmonary vascular resistance, and increased cardiac output. 3-BrPA significantly suppressed proliferation in addition to enhancing apoptosis of pulmonary artery smooth muscle cells, attenuating small pulmonary artery remodeling and right ventricular hypertrophy. Treatment with 3-BrPA markedly reduced the mitochondrial membrane potential and restored mitochondrial structure. Furthermore, 3-BrPA significantly inhibited HK 2 expression but not HK 1. The expression of both pyruvate dehydrogenase kinase and lactate dehydrogenase was decreased whereas that of pyruvate dehydrogenase and cytosolic cytochrome c was upregulated with 3-BrPA administration.

CONCLUSION

This study demonstrates the reversal of PH by 3-BrPA is related to alteration in glycolysis and improved mitochondria function, indicating the “metabolic targeting” as a rational therapeutic strategy for PH.
Can patients with cerebellar disease switch learning mechanisms to reduce their adaptation deficits?
Authors: Wong Aaron L , Marvel Cherie L , Taylor Jordan A , Krakauer John W
Published: December 2018

Systematic perturbations in motor adaptation tasks are primarily countered by learning from sensory-prediction errors, with secondary contributions from other learning processes. Despite the availability of these additional processes, particularly the use of explicit re-aiming to counteract observed target errors, patients with cerebellar degeneration are surprisingly unable to compensate for their sensory-prediction error deficits by spontaneously switching to another learning mechanism. We hypothesized that if the nature of the task was changed—by allowing vision of the hand, which eliminates sensory-prediction errors—patients could be induced to preferentially adopt aiming strategies to solve visuomotor rotations. To test this, we first developed a novel visuomotor rotation paradigm that provides participants with vision of their hand in addition to the cursor, effectively setting the sensory-prediction error signal to zero. We demonstrated in younger healthy control subjects that this promotes a switch to strategic re-aiming based on target errors. We then showed that with vision of the hand, patients with cerebellar degeneration could also switch to an aiming strategy in response to visuomotor rotations, performing similarly to age-matched participants (older controls). Moreover, patients could retrieve their learned aiming solution after vision of the hand was removed (although they could not improve beyond what they retrieved), and retain it for at least 1 year. Both patients and older controls, however, exhibited impaired overall adaptation performance compared to younger healthy controls (age 18–33 years), likely due to age-related reductions in spatial and working memory. Patients also failed to generalize, i.e. they were unable to adopt analogous aiming strategies in response to novel rotations. Hence, there appears to be an inescapable obligatory dependence on sensory-prediction error-based learning—even when this system is impaired in patients with cerebellar disease. The persistence of sensory-prediction error-based learning effectively suppresses a switch to target error-based learning, which perhaps explains the unexpectedly poor performance by patients with cerebellar degeneration in visuomotor adaptation tasks.
Human Immunodeficiency Virus Type 1 RNA Detected in the Central Nervous System (CNS) After Years of Suppressive Antiretroviral Therapy Can Originate from a Replicating CNS Reservoir or Clonally Expanded Cells
Authors: Joseph Sarah B , Kincer Laura P , Bowman Natalie M , Evans Chris , Vinikoor Michael J , Lippincott Christopher K , Gisslén Magnus , Spudich Serena , Menezes Prema , Robertson Kevin , Archin Nancie , Kashuba Angela , Eron Joseph J , Price Richard W , Swanstrom Ronald
Published: December 2018

Background

Human immunodeficiency virus type 1 (HIV-1) populations are detected in cerebrospinal fluid (CSF) of some people on suppressive antiretroviral therapy (ART). Detailed analysis of these populations may reveal whether they are produced by central nervous system (CNS) reservoirs.

Methods

We performed a study of 101 asymptomatic participants on stable ART. HIV-1 RNA concentrations were cross-sectionally measured in CSF and plasma. In participants with CSF HIV-1 RNA concentrations sufficient for analysis, viral populations were genetically and phenotypically characterized over multiple time points.

Results

For 6% of participants (6 of 101), the concentration of HIV-1 RNA in their CSF was ≥0.5 log copies/mL above that of plasma (ie, CSF escape). We generated viral envelope sequences from CSF of 3 participants. One had a persistent CSF escape population that was macrophage-tropic, partially drug resistant, genetically diverse, and closely related to a minor macrophage-tropic lineage present in the blood prior to viral suppression and enriched for after ART. Two participants (1 suppressed and 1 not) had transient CSF escape populations that were R5 T cell-tropic with little genetic diversity.

Conclusions

Extensive analysis of viral populations in 1 participant revealed that CSF escape was from a persistently replicating population, likely in macrophages/microglia, present in the CNS over 3 years of ART. CSF escape in 2 other participants was likely produced by trafficking and transient expansion of infected T cells in the CNS. Our results show that CNS reservoirs can persist during ART and that CSF escape is not exclusively produced by replicating CNS reservoirs.
Nonsecretor Histo–blood Group Antigen Phenotype Is Associated With Reduced Risk of Clinical Rotavirus Vaccine Failure in Malawian Infants
Authors: Pollock Louisa , Bennett Aisleen , Jere Khuzwayo C , Dube Queen , Mandolo Jonathan , Bar-Zeev Naor , Heyderman Robert S , Cunliffe Nigel A , Iturriza-Gomara Miren
Published: December 2018

Background

Histo–blood group antigen (HBGA) Lewis/secretor phenotypes predict genotype-specific susceptibility to rotavirus gastroenteritis (RVGE). We tested the hypothesis that nonsecretor/Lewis-negative phenotype leads to reduced vaccine take and lower clinical protection following vaccination with G1P[8] rotavirus vaccine (RV1) in Malawian infants

Methods

A cohort study recruited infants receiving RV1 at age 6 and 10 weeks. HBGA phenotype was determined by salivary enzyme-linked immunosorbent assay (ELISA). RV1 vaccine virus shedding was detected by quantitative real-time polymerase chain reaction (qRT-PCR) in stool collected on alternate days for 10 days post-immunization. Plasma rotavirus–specific immunoglobulin A was determined by ELISA pre- and post-immunization. In a case-control study, HBGA phenotype distribution was compared between RV1-vaccinated infants with RVGE and 1:1 age-matched community controls. Rotavirus genotype was determined by RT-PCR.

Results

In 202 cohort participants, neither overall vaccine virus fecal shedding nor seroconversion differed by HBGA phenotype. In 238 case-control infants, nonsecretor phenotype was less common in infants with clinical vaccine failure (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.20–0.75). Nonsecretor phenotype was less common in infants with P[8] RVGE (OR, 0.12; 95% CI, 0.03–0.50) and P[4] RVGE (OR, 0.17; 95% CI, 0.04–0.75). Lewis-negative phenotype was more common in infants with P[6] RVGE (OR, 3.2; 95% CI, 1.4–7.2).

Conclusions

Nonsecretor phenotype was associated with reduced risk of rotavirus vaccine failure. There was no significant association between HBGA phenotype and vaccine take. These data refute the hypothesis that high prevalence of nonsecretor/Lewis-negative phenotypes contributes to lower rotavirus vaccine effectiveness in Malawi.
Effects of Malaria in the First Trimester of Pregnancy on Poor Maternal and Birth Outcomes in Benin
Authors: Accrombessi Manfred , Yovo Emmanuel , Fievet Nadine , Cottrell Gilles , Agbota Gino , Gartner Agnès , Martin-Prevel Yves , Vianou Bertin , Sossou Darius , Fanou-Fogny Nadia , Djossinou Diane , Massougbodji Achille , Cot Michel , Briand Valérie
Published: December 2018

Background

In sub-Saharan Africa, malaria in the first half of pregnancy is harmful for both the mother and her fetus. However, malaria in the first trimester of pregnancy, when women are usually not protected against malaria, has been little investigated. For the first time, we assessed the effects of malaria in the first trimester on maternal and birth outcomes using a preconceptional study design.

Methods

From June 2014 to March 2017, 1214 women of reproductive age were recruited and followed monthly until 411 became pregnant. The pregnant women were then followed from 5–6 weeks of gestation until delivery. Path analysis was used to assess the direct effect (ie, not mediated by malaria in the second or third trimester) of malaria in the first trimester on maternal anemia and poor birth outcomes. The cumulative effect of infections during pregnancy on the same outcomes was also evaluated.

Results

The prevalence of malaria infections in the first trimester was 21.8%. Malaria in the first trimester was significantly associated with maternal anemia in the third trimester (adjusted odds ratio 2.25, 95% confidence interval 1.11–4.55). While we did not find evidence of any direct effect of first trimester malaria infections on birth outcomes, their association with infections later in pregnancy tended to increase the risk of low birth weights.

Conclusions

Malaria infections in the first trimester were highly prevalent and have deleterious effects on maternal anemia. They highlight the need for additional preventive measures, starting in early pregnancy or even before conception.
The Role of Construal Level in Message Effects Research: A Review and Future Directions
Authors: Lee Stella Juhyun
Published: December 2018

Construal level theory is a recent psychological theory that examines the relationship between psychological distance and mental construal. However, the theory’s implications for message effects research requires more attention. Construal level theory can guide new hypotheses that test the persuasiveness of certain combinations of message features and tailoring messages to different individual orientations. This is possible as the theory may reveal underlying similarities across disparate message topics, design elements, and message processing styles. Core principles of construal level theory are explicated, and message effects research areas that may benefit from its propositions are reviewed and elaborated upon. Finally, caveats of applying the theory to message effects research and future directions are discussed.
Analysis of hidradenitis suppurativa–linked mutations in four genes and the effects of PSEN1-P242LfsX11 on cytokine and chemokine expression in macrophages
Authors: Li Airong , Peng Yang , Taiclet Lauren M , Tanzi Rudolph E
Published: December 2018

Hidradenitis suppurativa (HS), or acne inversa, is a chronic inflammatory skin disorder characterized clinically with acne-like lesions in apocrine gland–bearing skin, follicular occlusion and recurrent inflammation. Thirty-four unique mutations in patients with HS have been found in three genes encoding the γ-secretase complex: nicastrin (NCSTN), presenilin 1 (PSEN1), presenilin enhancer 2 (PSENEN) and in POGLUT1, an endoplasmic reticulum O-glucosyltransferase involved in Notch signaling. We have carried out a system review and have performed a functional analysis of the 34 unique reported HS-linked mutations in NCSTN, PSEN1, PSENEN and POGLUT1. We have also examined the effects of the HS-linked PSEN1-P242LfsX11 mutation on cytokine and chemokine expression in macrophages. Mutations in NCSTN are predicted to cause loss of function, to result in loss of transmembrane (TM) domain, to affect NCSTN substrate recruitment sites, to cause loss or creation of new ligand binging sites and to alter post-translational modifications and disulfide bonds. PSEN1-P242LfsX11 occurs at the opposite side of TM5 from Alzheimer’s disease–linked PSEN1 mutations. All of the PSENEN mutations occur on TM regions that are predicted to disrupt membrane function. POGLUT1 mutations lead to an early termination of protein synthesis and are predicted to affect ligand binding function. In addition, PSEN1-P242LfsX11 mediates cytokine and chemokine expression and prolongs tumor necrosis factor α production on the inflammatory processes in THP-1 cells and phorbol-12-myristate-13-acetate–differentiated macrophages in response to lipopolysaccharide stimulation. These in silico analyses are instructive for functional studies of the HS-linked mutations. The PSEN1-P242LfsX11 mutation mediates cytokine and chemokine expression in macrophages.
Evolution Equations for Non-Degenerate 2-Forms
Authors: He Weiyong
Published: December 2018

In this paper we introduce several geometric flows that evolve primarily non-degenerate 2-forms, with the motivation to develop a geometric flow to approach the existence of the symplectic forms on a compact manifold that supports a non-degenerate 2-form. In particular, we introduce $\mathrm{d}^{\ast }\mathrm{d}$-flow and $\mathrm{d}^{\ast }\mathrm{d}$-Ricci flow for a compatible pair $(\omega , J)$ of an almost Hermitian structure. We prove the short time existence and uniqueness of these flows with smooth initial data, and give some examples of long time existence and convergence.
Population Differentiation Within Anisogramma anomala in North America
Authors: Muehlbauer Megan F. , Tobia Janine , Honig Joshua A. , Zhang Ning , Hillman Bradley I. , Gold Kaitlin Morey , Molnar Thomas J.
Published: December 2018

Anisogramma anomala, a biotrophic ascomycete in the order Diaporthales, causes eastern filbert blight (EFB) of hazelnuts (Corylus spp.). Until recently, little has been documented on its genetic diversity and population structure. In this study, 18 simple sequence repeat markers were used to fingerprint 182 accessions of the fungus originating from across North America. Our results, based on summary statistics of the allelic data, a discriminant analysis of principal components (DAPC) scatterplot, an unweighted pair group method with arithmetic mean (UPGMA) dendrogram, and analysis of multilocus genotypes, show that A. anomala exhibits considerable genetic diversity across multiple populations. Eleven clusters were resolved from the DAPC scatterplot, five of which were validated by statistically supported clusters in the UPGMA dendrogram. The 11 DAPC clusters were statistically significant via an analysis of molecular variance. Dendrogram topology and DAPC scatterplot groups showed some correlation with collection origin; samples collected in proximity tended to cluster together and be genetically similar. However, some locations held populations that were diverse and some populations with a high degree of similarity had disparate origins, suggesting movement by humans. Overall, the results demonstrate the presence of multiple, genetically distinct populations of A. anomala in North America and serve as a reference to assist in understanding and managing EFB.
Reduction Techniques for Young Femoral Neck Fractures
Authors: Halvorson Jason
Published: December 2018

Young femoral neck fractures remain challenging fractures to treat. Reduction has repeatedly been shown to be the single most important determinant of patient outcome, and treating surgeons should do all they can to achieve anatomic reduction because this is an outcome variable within the surgeon's control. Whether an open or closed reduction is performed, we hope to provide the reader with reduction strategies when faced with this difficult fracture pattern. In addition, we hope to review indications and techniques for using the various treatment implants/modalities that are currently available as they pertain to reduction and fixation.
Thiosocius teredinicola gen. nov., sp. nov., a sulfur-oxidizing chemolithoautotrophic endosymbiont cultivated from the gills of the giant shipworm, Kuphus polythalamius
Authors: Altamia Marvin A. , Shipway J. Reuben , Concepcion Gisela P. , Haygood Margo G. , Distel Daniel L.
Published: December 2018

A chemolithoautotrophic sulfur-oxidizing, diazotrophic, facultatively heterotrophic, endosymbiotic bacterium, designated as strain 2141T, was isolated from the gills of the giant shipworm Kuphus polythalamius (Teredinidae: Bivalvia). Based on its 16S rRNA sequence, the endosymbiont falls within a clade that includes the as-yet-uncultivated thioautotrophic symbionts of a marine ciliate and hydrothermal vent gastropods, uncultivated marine sediment bacteria, and a free-living sulfur-oxidizing bacterium ODIII6, all of which belong to the Gammaproteobacteria. The endosymbiont is Gram-negative, rod-shaped and has a single polar flagellum when grown in culture. This bacterium can be grown chemolithoautotrophically on a chemically defined medium supplemented with either hydrogen sulfide, thiosulfate, tetrathionate or elemental sulfur. The closed-circular genome has a DNA G+C content of 60.1 mol% and is 4.79 Mbp in size with a large nitrogenase cluster spanning nearly 40 kbp. The diazotrophic capability was confirmed by growing the strain on chemolithoautotrophic thiosulfate-based medium without a combined source of fixed nitrogen. The bacterium is also capable of heterotrophic growth on organic acids such as acetate and propionate. The pH, temperature and salinity optima for chemolithoautotrophic growth on thiosulfate were found to be 8.5, 34 °C and 0.2 M NaCl, respectively. To our knowledge, this is the first report of pure culture of a thioautotrophic animal symbiont. The type strain of Thiosocius teredinicola is PMS-2141T.STBD.0c.01aT (=DSM 108030T).
Evolutionary games with environmental feedbacks
Authors: Tilman Andrew R. , Plotkin Joshua , Akçay Erol
Published: December 2018

Strategic interactions form the basis for evolutionary game theory and often occur in dynamic environments. The various strategies employed in a population may alter the quality or state of the environment, which may in turn feedback to change the incentive structure of strategic interactions. This type of feedback is common in social-ecological systems, evolutionary-ecological systems, and even psychological-economic systems – where the state of the environment alters the dynamics of competing types, and vice versa. Here we develop a framework of “eco-evolutionary game theory” that permits the study of joint strategic and environmental dynamics, with feedbacks. We consider environments governed either by a renewable resource (e.g. common-pool harvesting) or a decaying resource (e.g. pollution byproducts). We show that the dynamics of strategies and the environment depend, crucially, on the incentives for individuals to lead or follow behavioral changes, and on the relative speed of environmental versus strategic change. Our analysis unites dynamical phenomena that occur in settings as diverse as human decision-making, plant nutrient acquisition, and resource harvesting. We discuss the implication of our results for fields ranging from ecology to economics.
Loss of Sarm1 non-autonomously protects Schwann cells from chemotoxicity
Authors: Tian Weili , Czopka Tim , López-Schier Hernán
Published: December 2018

The obligate pro-degenerative protein Sarm1 is essential for Wallerian axon degeneration. Inhibition of Sarm1 has been proposed as a promising neuroprotective strategy with clinical relevance. Yet, the conditions that will most benefit from inhibiting Sarm1 remain undefined. Here we use genetics and pharmacology in zebrafish to show that systemic elimination of Sarm1 is glioprotective. Loss of Sarm1 does not affect macrophage recruitment to the wound microenvironment, focal injury resolution, or nerve repair. Unexpectedly, Sarm1 deficiency increases Schwann-cell resistance to toxicity by diverse chemotherapeutic agents after neuronal injury. Yet, synthetic degradation of Sarm1-deficient severed axons reversed this effect, suggesting that glioprotection is non-cell-autonomous. These findings anticipate that interventions aimed at inhibiting Sarm1 can counter heightened glial vulnerability to chemical stressors and may be an effective strategy to reduce chronic consequences of neurotrauma.
pcaExplorer: an R/Bioconductor package for interacting with RNA-seq principal components
Authors: Marini Federico , Binder Harald
Published: December 2018

Background

Principal component analysis (PCA) is frequently useentirely written ind in genomics applications for quality assessment and exploratory analysis in high-dimensional data, such as RNA sequencing (RNA-seq) gene expression assays. Despite the availability of many software packages developed for this purpose, an interactive and comprehensive interface for performing these operations is lacking.

Results

We developed the pcaExplorer software package to enhance commonly performed analysis steps with an interactive and user-friendly application, which provides state saving as well as the automated creation of reproducible reports. pcaExplorer is implemented in R using the Shiny framework and exploits data structures from the open-source Bioconductor project. Users can easily generate a wide variety of publication-ready graphs, while assessing the expression data in the different modules available, including a general overview, dimension reduction on samples and genes, as well as functional interpretation of the principal components.

Conclusion

pcaExplorer is distributed as an R package in the Bioconductor project (http://bioconductor.org/packages/pcaExplorer/), and is designed to assist a broad range of researchers in the critical step of interactive data exploration.
Serum GlycA level is a candidate biomarker for disease activity in systemic lupus erythematosus and for proliferative status of lupus nephritis, independent of renal function impairment.
Authors: Dierckx Tim , Goletti Sylvie , Chiche Laurent , Daniel Laurent , Lauwerys Bernard , Jourde-Chiche Noemie , Van Weyenbergh Johan
Published: December 2018

Objective: Glycoprotein acetylation (GlycA) is a novel biomarker for chronic inflammation, associated to cardiovascular risk. Serum GlycA levels are increased in several inflammatory diseases, including systemic lupus erythematosus (SLE). We investigated the relevance of serum GlycA measurement in SLE and lupus nephritis (LN).
Methods: GlycA was measured by NMR in 194 serum samples from patients and controls. Comparisons were performed between groups. Clinical and biological parameters were tested for correlation with GlycA levels. The predictive value of GlycA to differentiate proliferative from non-proliferative LN was determined using logistic regression models.
Results: GlycA was correlated to C-reactive protein (CRP), neutrophil count, proteinuria and the SLE disease activity index (SLEDAI), and inversely with serum albumin. GlycA was higher in active (n=105) than in quiescent (n=39) SLE patients, in healthy controls (n=29), and in patients with non-lupus nephritis (n=21), despite a more altered renal function in the latter. In patients with biopsy-proven active LN, GlycA was higher in proliferative (n=32) than non-proliferative (n=11) LN, independent of renal function and proteinuria level. Logistic regression models showed that, in univariate models, GlycA outperforms traditional biomarkers. A bivariate model using GlycA and BMI better predicted the proliferative status of LN than a model comprising CRP, renal function (eGFR), serum albumin, proteinuria, C3 consumption and the presence of anti-dsDNA antibodies.
Conclusion: Serum GlycA is elevated in SLE, and correlates with disease activity and LN. Serum GlycA, which summarizes different inflammatory processes, could be a valuable biomarker to discriminate proliferative from non-proliferative LN and should be tested in large, prospective cohorts.
Mechanical and kinetic factors drive sorting of F-actin crosslinkers on bundles
Authors: Freedman Simon L , Suarez Cristian , Winkelman Jonathan D , Kovar David R , Voth Gregory A , Dinner Aaron R. , Hocky Glen M
Published: December 2018

In cells, actin binding proteins (ABPs) sort to different regions in order to establish F-actin networks with diverse functions, including filopodia used for cell migration, or contractile rings required for cell division. Recent experimental work uncovered a passive mechanism that may facilitate spatial localization of ABPs: binding of a short crosslinker protein to two actin filaments promotes the binding of other short crosslinkers and inhibits the binding of longer crosslinkers (and vice versa). We hypothesize this sorting arises because F-actin is semiflexible and cannot bend over short distances. We develop a mathematical theory and a kinetic Monte Carlo simulation encompassing the most important physical parameters for this process, and use simulations of a coarse-grained but molecularly explicit model to characterize and test our predictions about the interplay of mechanical and kinetic parameters. Our theory and data predict an explicit dependence of crosslinker separation on bundle polymerization rate. We perform experiments that confirm a dependence on polymerization rate, but in an unanticipated non-monotonic manner. We use simulations to show that this non-monotonic behavior can arise in situations where crosslinkers have equal bundling affinity at equilibrium, but differing microscopic binding rates to filaments. This dependence of sorting on actin polymerization rate is a non-equilibrium effect, qualitatively similar to non-equilibrium domain formation in materials growth. Thus our results reveal an avenue by which cells can organize molecular material to drive biological processes, and can also guide the choice and design of crosslinkers for engineered protein-based materials.
Factors influencing the measurement of assimilation and stomatal conductance with the LI-COR 6400XT gas exchange system.
Authors: LeCain Daniel , Gleason Sean
Published: December 2018

Abstract: Although CO2 and H2O exchange rates are often measured in experiments as indicators of physiological plant responses these gas exchange measurements are prone to large experimental error. Gas exchange equipment and technology have improved greatly over the past two decades which supports scrutinizing current issues of experimental error in measuring plant photosynthesis and stomatal conductance. This report shows results of a greenhouse experiment with the goal of identifying lessor understood sources of experimental error and variation in measurements with the LI-COR 6400XT gas exchange system. A variety of plant types were used to encompass differing species variation. We found significant sources of experimental error in 1) the time for initial adjustment when placing a leaf in the leaf chamber 2) the time-of-day when measuring 3) leaf age 4) having the chamber window full vs. partially full with leaf tissue 5) using a leaf chamber environment that greatly diverges from the whole plant environment 6) differing degree of experimental error depending upon plant species. A situation with multiple contributors to error would result in useless gas-exchange data. Recommendations for minimizing these experimental errors are given.
Resolving cell cycle speed in one snapshot with a live-cell fluorescent reporter
Authors: Eastman Anna E. , Chen Xinyue , Hu Xiao , Hartman Amaleah A. , Pearlman Morales Aria M. , Yang Cindy , Lu Jun , Kueh Hao Yuan , Guo Shangqin
Published: December 2018

Cell proliferation changes concomitantly with fate transitions during reprogramming, differentiation, regeneration, and oncogenesis. Methods to resolve cell cycle length heterogeneity in real-time are currently lacking. Here, we describe a genetically encoded fluorescent reporter that captures live cell cycle speed using a single measurement. This reporter is based on the color-changing Fluorescent Timer (FT) protein, which emits blue fluorescence when newly synthesized before maturing into a red fluorescent protein. We generated a mouse strain expressing an H2B-FT fusion reporter from a universally active locus, and demonstrate that faster-cycling cells can be distinguished from slower-cycling ones based on the intracellular fluorescence ratio between the FT’s blue and red states. Using this reporter, we reveal the native cell cycle speed distributions of fresh hematopoietic cells, and demonstrate its utility in analyzing cell proliferation in solid tissues. This system is broadly applicable for dissecting functional heterogeneity associated with cell cycle dynamics in complex tissues.
Critical Role of Histone Tail Entropy in Nucleosome Unwinding
Authors: Zhang Bin , Parsons Thomas
Published: December 2018

The nucleosome is the fundamental packaging unit for the genome. It must both remain tightly wound to ensure genome stability while simultaneously being flexible enough to keep the DNA molecule accessible for genome function. The set of physicochemical interactions responsible for the delicate balance between these naturally opposed processes have not been determined due to challenges in resolving partially unwound nucleosome configurations at atomic resolution. Using a near atomistic protein-DNA model and advanced sampling techniques, we calculate the free energy cost of nucleosome DNA unwinding. Our simulations identify a large energetic barrier that decouples the outer and inner DNA unwinding into two separate processes, occurring on different timescales. This dynamical decoupling allows the exposure of outer DNA at a modest cost to ensure accessibility while keeping the inner DNA and the histone core intact to maintain stability. We also reveal that this energetic barrier arises from a delayed loss of contacts between disordered histone tails and the DNA, and is, surprisingly, largely offset by an entropic contribution from these tails. Our study uncovers the balance of energetic and entropic contributions that dictate nucleosome stability, suggesting that tilting this balance may be a previously-unknown mechanism for regulating genome function.
Establishment of the mayfly Cloeon dipterum as a new model system to investigate insect evolution
Authors: Almudi Isabel , Martin-Blanco Carlos , Garcia-Fernandez Isabel Maria , Lopez-Catalina Adrian , Davie Kristofer , Aerts Stein , Casares Fernando
Published: December 2018

The great capability of insects to adapt to new environments promoted their extraordinary diversification, resulting in the group of Metazoa with the largest number of species distributed worldwide. To understand this enormous diversity, it is essential to investigate lineages that would allow the reconstruction of the early events in the evolution of insects. However, research on insect ecology, physiology, development and evolution has mostly focused on few well-established model species. The key phylogenetic position of mayflies within Paleoptera, as the sister group of the rest of winged insects and life history traits of mayflies make them an essential order to understand insect evolution. Here, we describe the established of a continuous culture system of the mayfly Cloeon dipterum and a series of experimental protocols and -omics resources that allow the study of its development and its great regenerative capability. Thus, the establishment of Cloeon as an experimental platform paves the way to understand genomic and morphogenetic events that occurred at the origin of winged insects.