bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of Genetic Variability in Borrelia miyamotoi (Spirochaetales: Spirochaetaceae) Between and Within the Eastern and Western United States
Authors: Hojgaard Andrias , Osikowicz Lynn M , Maes Sarah , Eisen Lars , Eisen Rebecca J
Published: May 2021

Borrelia miyamotoi is a hard tick-associated relapsing fever spirochete that is geographically widespread in Ixodes spp. (Acari: Ixodidae) ticks, but typically occurs at low prevalence. Genetic variability has been described among strains derived from Asia, Europe, and North America, and among tick species that carry the infection, but little variability has been described within foci or tick species. Capitalizing on access to B. miyamotoi nucleic acid extracted from host-seeking Ixodes scapularis Say or Ixodes pacificus Cooley & Kohls from 16 states, we explored genetic variability based on sequence analysis of four amplicons described herein. Consistent with previous studies, we detected significant genetic differences between strains derived from I. scapularis (eastern United States) and I. pacificus (western United States) and identified two distinct sequences in the western United States (Am-West-1 and Am-West-2). Unique to this study, we identified two distinct sequences in the eastern United States (Am-East-1 and Am-East-2). Based on the 161 samples we analyzed, Am-East-1 was the only type represented in 50 B. miyamotoi-infected ticks collected from the Northeast (Vermont, Maine, New York, Connecticut, and Rhode Island), whereas ticks collected from the North-Central and Mid-Atlantic states harbored B. miyamotoi comprised of both Am-East-1 and Am-East-2. Further studies are needed to better characterize the phylogeography of B. miyamotoi and to discern if there are biologically meaningful differences among sequence types. To facilitate further exploration, we developed a polymerase chain reaction (PCR) assay designed to differentiate Am-East-1, Am-East-2, and Am-West sequence types without having to sequence the amplicon.
Study on the dissolution of β-precipitates in the Zr–1Nb alloy under the influence of Ne ion irradiation
Authors: Goel Lokesh , Mir Anamul H , Naveen Kumar N , Satyam Parlapalli V , Hinks Jonathan A , Donelly Stephen E , Tewari Raghvendra
Published: May 2021

The stability of β-precipitates in the Zr–1Nb alloy has been studied under Ne ion irradiation of energy 250 keV by insitu transmission electron microscope as a function of irradiation dose. The irradiation was carried out up to ∼136 dpa at 573 K. Microstructural investigations have shown that up to ∼38 dpa, precipitates showed an increase in size, and for irradiation doses >38 dpa, the size of the precipitates was noticed to reduce. Post-irradiation energy-dispersive spectrometry of the specimens revealed the Nb concentration throughout the matrix to be ∼0.8–1.5%. Three-dimensional atom probe tomography was also carried out for irradiated specimens to look for the presence of any nanoclusters. However, Nb clustering was not observed in the specimens. It is proposed that the dissolution of the precipitates may be facilitated by an increase in the solubility limit of Nb in Zr caused by irradiation. The solubility limit may increase by the introduction of defects generated by irradiation and by the destabilization of the β-phase. This may result in back-diffusion of Nb atoms to the matrix by radiation-enhanced diffusion to lower the strain produced by the defects, resulting in the dissolution of the precipitates.
Introducing SYSPROP—A Software Tool to Identify Small but Economically Viable Timber Parcels in the Pacific Northwest
Authors: Helderop Edward , Grubesic Tony H , Edson Clayton N
Published: May 2021

The past several decades have seen a steady decline in timber harvest rates from many parts of the United States, particularly the Pacific Northwest. Although various factors fuel this decline, one of the principal drivers is increasing rates of parcelization of the landscape. Increasingly parcelized forested landscapes tend to be more challenging to log—both because urbanization rates are somewhat correlated with parcelization but also due to the additional administrative overhead in securing logging rights in increasingly smaller parcels. The purpose of this note is to introduce SYSPROP, a tool to aid in the automatic identification of economically viable parcels for logging. We conclude with a case study of a small logging company operating in Washington State that used this tool to identify several promising parcels.
The transcription factor KNAT2/6b mediates changes in plant architecture in response to drought via down-regulating GA20ox1 in Populus alba × P. glandulosa
Authors: Song Xueqin , Zhao Yanqiu , Wang Jinnan , Lu Meng-Zhu
Published: May 2021

Plant architecture is genetically controlled, but is influenced by environmental factors. Plants have evolved adaptive mechanisms that allow changes in their architecture under stress, in which phytohormones play a central role. However, the gene regulators that connect growth and stress signals are rarely reported. Here, we report that a class I KNOX gene, PagKNAT2/6b, can directly inhibit the synthesis of gibberellin (GA), altering plant architecture and improving drought resistance in Populus. Expression of PagKNAT2/6b was significantly induced under drought conditions, and transgenic poplars overexpressing PagKNAT2/6b exhibited shorter internode length and smaller leaf size with short or even absent petioles. Interestingly, these transgenic plants showed improved drought resistance under both short- and long-term drought stress. Histological observations indicated that decreased internode length and leaf size were mainly caused by the inhibition of cell elongation and expansion. GA content was reduced, and the GA20-oxidase gene PagGA20ox1 was down-regulated in overexpressing plants. Expression of PagGA20ox1 was negatively related to that of PagKNAT2/6b under drought stress. ChIP and transient transcription activity assays revealed that PagGA20ox1 was directly targeted by PagKNAT2/6b. Therefore, this study provides evidence that PagKNAT2/6b mediates stress signals and changes in plant architecture via GA signaling by down-regulating PagGA20ox1.
Plant thermotropism: an underexplored thermal engagement and avoidance strategy
Authors: van Zanten Martijn , Ai Haiyue , Quint Marcel
Published: May 2021

Various strategies evolved in plants to adjust the position of organs relative to the prevailing temperature condition, which allows optimal plant growth and performance. Such responses are classically separated into nastic and tropic responses. During plant thermotropic responses, organs move towards (engage) or away from (avoid) a directional temperature cue. Despite thermotropism being a classic botanical concept, the underlying ecological function and molecular and biophysical mechanisms remain poorly understood to this day. This is in contrast to the relatively well-studied thermonastic movements (hyponasty) of, for example, rosette leaves. In this review, we provide an update on the current knowledge on plant thermotropisms and propose directions for future research and application.
KK Failures Are Not Abominable
Authors: Fraser Rachel Elizabeth
Published: May 2021

Kevin Dorst has recently provided a novel argument for the KK principle.

In this paper I sketch a rejoinder.
Constraining the ratio of median pixel optical depth profile around z ∼ 4 quasars using the longitudinal proximity effect
Authors: Jalan Priyanka , Chand Hum , Srianand Raghunathan
Published: May 2021

We present a detailed study of the longitudinal proximity effect using a sample of 85 quasars spanning an emission redshift range of 3.5 ≤ zem ≤ 4.5 and Lyman continuum luminosity (L912) ranging from 1.06 × 1031 to 2.24 × 1032 erg s−1 Hz−1. We use the high-quality spectra of these quasars obtained at a spectral resolution of R ∼ 5100 and S/N ∼ 30 using X-SHOOTER spectrograph mounted on the Very Large Telescope (VLT). In our analysis, we compared the transmitted flux and pixel optical depth of the Ly α absorption originating from the vicinity of quasars to those from the general intergalactic medium (IGM) by using a redshift-matched control sample. The longitudinal proximity effect is found up to r ≤ 12 Mpc (proper) from quasars. By appropriately scaling up the pixel optical depth in the vicinity of quasars to account for the excess ionization by quasars, we constrain the ratio of median H i optical depth in the vicinity of the quasar to that of the IGM (Rτ(r)). The Rτ(r) is found to be significantly higher than unity up to 6 Mpc from the quasar with a typical radial profile of the form Rτ(r) = 1 + A × exp(− r/r0) with A = 9.16 ± 0.68 and r0 = 1.27 ± 0.08 Mpc. The integrated value of the scaled pixel optical depth over the radial bin of 0–6 Mpc is found to be higher by a factor of 2.55 ± 0.17 than the corresponding integrated value of the median pixel optical depth of the IGM. We also found Rτ(r) to be luminosity dependent.
Modelling of atmospheric optical turbulence with the Weather Research and Forecasting model at the Ali observatory, Tibet
Authors: Qian Xuan , Yao Yongqiang , Zou Lei , Wang Hongshuai , Yin Jia , Li Yao
Published: May 2021

In this study, we make use of a meso-scale numerical model to obtain the parameters of atmospheric optical turbulence at the Ali observatory above the Tibetan Plateau. These parameters are essential for ground-based optical observations and some adaptive optics techniques. We present the characterization of the vertical distributions of atmospheric optical turbulence Cn2 and the main integral parameters, such as coherence time τ0, isoplanatic angle θ0 and seeing ε0 derived from Cn2. Meanwhile, the measurement of Cn2 obtained with a radiosonde instrument is used to quantify the model performance on reconstructing the optical turbulence above the site. This shows a high level of agreement and provides a reliable tool for astronomical site testing. The results presented in this paper demonstrate the good behaviour of the atmospheric optical turbulence condition at Ali, particularly during the summer half of the year. We find yearly median values of seeing ε0 = 0.47 arcsec, isoplanatic angle θ0 = 4.35 arcsec and atmospheric coherence time τ0 = 5.52 ms in 2016, and we also provide independent confirmation of the potential of the Ali site in adaptive optics. Moreover, it has been proven that meso-scale models can provide reliable estimations of atmospheric optical turbulence conditions above an astronomical site on the Tibetan Plateau.
Magneto-hydrodynamic simulations of young supernova remnants and their energy-conversion phase
Authors: Petruk O , Kuzyo T , Orlando S , Pohl M , Brose R
Published: May 2021

Supernova remnants (SNRs) can be rich sources of information on the parent SN (supernova) explosion. Thus, investigating the transition from the phase of SN to that of SNR can be crucial to link these two phases of evolution. Here, we aim to study the early development of SNR in more detail, paying the major attention to the transition from the early expansion stage to the Sedov stage and the role played by magnetic field in this transition. To this end, spherical magnetohydrodynamic simulations of SNRs have been performed to study the evolution of magnetic field in young SNRs and explore a sequence of the SNR evolutionary stages in the pre-radiative epoch. Remnants of three supernova types are considered, namely, SNIa, SNIc, and SNIIP, that covers a wide space of parameters relevant for SNRs. Changes in global characteristics and development of spatial distributions are analysed. It is shown that the radial component of magnetic field rapidly drops downstream of the forward shock. Therefore, the radially aligned polarization patterns observed in few young SNRs cannot be reproduced in the 1D MHD simulations. The period SNR takes for the transition from the earliest ejecta-driven phase to the Sedov phase is long enough, with its distinctive physical features, headed by the energy conversion from mostly kinetic one to a fixed ratio between the thermal and kinetic components. This transition worth to be distinguished as a phase in SNR evolutionary scheme. The updated sequence of stages in SNR evolution could be the free expansion (of gas) – energy conversion – Sedov–Taylor – post-adiabatic – radiative.
Cosmic rays and non-thermal emission in simulated galaxies – II. γ-ray maps, spectra, and the far-infrared–γ-ray relation
Authors: Werhahn Maria , Pfrommer Christoph , Girichidis Philipp , Winner Georg
Published: May 2021

The γ-ray emission of star-forming (SF) galaxies is attributed to hadronic interactions of cosmic ray (CR) protons with the interstellar gas and contributions from CR electrons via bremsstrahlung and inverse Compton (IC) scattering. The relative importance of these processes in different galaxy types is still unclear. We model these processes in three-dimensional magnetohydrodynamical (MHD) simulations of the formation of isolated galactic discs using the moving-mesh code arepo, including dynamically coupled CR protons and adopting different CR transport models. We calculate steady-state CR spectra and also account for the emergence of secondary electrons and positrons. This allows us to produce detailed γ-ray maps, luminosities, and spectra of our simulated galaxies at different evolutionary stages. Our simulations with anisotropic CR diffusion and a low CR injection efficiency at supernovae (SNe; $\zeta_\mathrm{SN}=0.05$) can successfully reproduce the observed far-infrared (FIR)–γ-ray relation. Starburst galaxies are close to the calorimetric limit, where CR protons lose most of their energy due to hadronic interactions and hence, their γ-ray emission is dominated by neutral pion decay. However, in low SF galaxies, the increasing diffusive losses soften the CR proton spectra due to energy-dependent diffusion, and likewise steepen the pionic γ-ray spectra. In turn, IC emission hardens the total spectra and can contribute up to ∼40 per cent of the total luminosity in low SF galaxies. Furthermore, in order to match the observed γ-ray spectra of starburst galaxies, we require a weaker energy dependence of the CR diffusion coefficient, $D\propto E^{0.3}$, in comparison to Milky Way-like galaxies.
Modelling synchrotron and synchrotron self-Compton emission of gamma-ray burst afterglows from radio to very-high energies
Authors: Joshi Jagdish C , Razzaque Soebur
Published: May 2021

Synchrotron radiation from a decelerating blastwave is a widely accepted model of radio to X-ray afterglow emission from gamma-ray bursts (GRBs). GeV gamma-ray emission detected by the Fermi Large Area Telescope (LAT) and the duration of which extends beyond the prompt gamma-ray emission phase is also compatible with broad features of afterglow emission. We revisit the synchrotron self-Compton (SSC) emission model from a decelerating blastwave to fit multiwavelength data from three bright GRBs, namely GRB 190114C, GRB 130427A, and GRB 090510. We constrain the afterglow model parameters using the simultaneous fit of the spectral energy distributions at different times and light curves at different frequencies for these bursts. We find that a constant density interstellar medium is favoured for the short GRB 090510, while a wind-type environment is favoured for the long GRB 130427A and GRB 190114C. The sub-TeV component in GRB 190114C detected by MAGIC is the SSC emission in our modelling. Furthermore, we find that the SSC emission in the Thomson regime is adequate to fit the spectra and light curves of GRB 190114C. For the other two GRBs, lacking sub-TeV detection, the SSC emissions are also modelled in the Thomson regime. For the model parameters we have used, the γγ attenuation in the blastwave is negligible in the sub-TeV range compared to the redshift-dependent γγ attenuation in the extragalactic background light.
Apsidal asymmetric-alignment of Jupiter Trojans
Authors: Li Jian , Lei Hanlun , Xia Zhihong J
Published: May 2021

The most distant Kuiper belt objects exhibit the clustering in their orbits, and this anomalous architecture could be caused by Planet 9 with large eccentricity and high inclination. We then suppose that the orbital clustering of minor planets may be observed somewhere else in the Solar system. In this paper, we consider the over 7000 Jupiter Trojans from the Minor Planet Center, and find that they are clustered in the longitude of perihelion ϖ, around the locations ϖJ + 60○ and ϖJ − 60○ (ϖJ is the longitude of perihelion of Jupiter) for the L4 and L5 swarms, respectively. Then we build a Hamiltonian system to describe the associated dynamical aspects for the co-orbital motion. The phase space displays the existence of the apsidally aligned islands of libration centred on Δϖ = ϖ − ϖJ ≈ ±60○, for the Trojan-like orbits with eccentricities e < 0.1. Through a detailed analysis, we have shown that the observed Jupiter Trojans with proper eccentricities ep < 0.1 spend most of their time in the range of |Δϖ| = 0°–120○, while the more eccentric ones with ep > 0.1 are too few to affect the orbital clustering within this Δϖ range for the entire Trojan population. Our numerical results further prove that, even starting from a uniform Δϖ distribution, the apsidal alignment of simulated Trojans similar to the observation can appear on the order of the age of the Solar system. We conclude that the apsidal asymmetric-alignment of Jupiter Trojans is robust, and this new finding can be helpful to design the survey strategy in the future.
Hierarchical black hole mergers in young, globular and nuclear star clusters: the effect of metallicity, spin and cluster properties
Authors: Mapelli Michela , Dall’Amico Marco , Bouffanais Yann , Giacobbo Nicola , Arca Sedda Manuel , Artale M Celeste , Ballone Alessandro , Di Carlo Ugo N , Iorio Giuliano , Santoliquido Filippo , Torniamenti Stefano
Published: May 2021

We explore hierarchical black hole (BH) mergers in nuclear star clusters (NSCs), globular clusters (GCs) and young star clusters (YSCs), accounting for both original and dynamically assembled binary BHs (BBHs). We find that the median mass of both first- and nth-generation dynamical mergers is larger in GCs and YSCs with respect to NSCs because the lighter BHs are ejected by supernova kicks from the lower mass clusters. Also, first- and nth-generation BH masses are strongly affected by the metallicity of the progenitor stars: the median mass of the primary BH of a nth-generation merger is ∼24–38 M⊙ (∼9–15 M⊙) in metal-poor (metal-rich) NSCs. The maximum BH mass mainly depends on the escape velocity: BHs with mass up to several thousand M⊙ form in NSCs, while YSCs and GCs host BHs with mass up to several hundred M⊙. Furthermore, we calculate the fraction of mergers with at least one component in the pair-instability mass gap (fPI) and in the intermediate-mass BH regime (fIMBH). In the fiducial model for dynamical BBHs with metallicity Z = 0.002, we find fPI ≈ 0.05, 0.02 and 0.007 (fIMBH ≈ 0.01, 0.002 and 0.001) in NSCs, GCs and YSCs, respectively. Both fPI and fIMBH drop by at least one order of magnitude at solar metallicity. Finally, we investigate the formation of GW190521 by assuming that it is either a nearly equal-mass BBH or an intermediate-mass ratio inspiral.
Resource Uptake and the Evolution of Moderately Efficient Enzymes
Authors: Labourel Florian , Rajon Etienne
Published: May 2021

Enzymes speed up reactions that would otherwise be too slow to sustain the metabolism of selfreplicators. Yet, most enzymes seem only moderately efficient, exhibiting kinetic parameters orders of magnitude lower than their expected physically achievable maxima and spanning over surprisingly large ranges of values. Here, we question how these parameters evolve using a mechanistic model where enzyme efficiency is a key component of individual competition for resources. We show that kinetic parameters are under strong directional selection only up to a point, above which enzymes appear to evolve under near-neutrality, thereby confirming the qualitative observation of other modeling approaches. While the existence of a large fitness plateau could potentially explain the extensive variation in enzyme features reported, we show using a population genetics model that such a widespread distribution is an unlikely outcome of evolution on a common landscape, as mutation–selection–drift balance occupy a narrow area even when very moderate biases towards lower efficiency are considered. Instead, differences in the evolutionary context encountered by each enzyme should be involved, such that each evolves on an individual, unique landscape. Our results point to drift and effective population size playing an important role, along with the kinetics of nutrient transporters, the tolerance to high concentrations of intermediate metabolites, and the reversibility of reactions. Enzyme concentration also shapes selection on kinetic parameters, but we show that the joint evolution of concentration and efficiency does not yield extensive variance in evolutionary outcomes when documented costs to protein expression are applied.
Kinetics of γH2AX and phospho-histone H3 following pulse treatment of TK6 cells provides insights into clastogenic activity
Authors: Bryce Steven M , Dertinger Stephen D , Bemis Jeffrey C
Published: May 2021

The desire for in vitro genotoxicity assays to provide higher information content, especially regarding chemicals’ predominant genotoxic mode of action, has led to the development of a novel multiplexed assay available under the trade name MultiFlow®. We report here on an experimental design variation that provides further insight into clastogens’ genotoxic activity. First, the standard MultiFlow DNA Damage Assay—p53, γ H2AX, phospho-histone H3 was used with human TK6 lymphoblastoid cells that were exposed for 24 continuous hours to each of 50 reference clastogens. This initial analysis correctly identified 48/50 compounds as clastogenic. These 48 compounds were then evaluated using a short-term, ‘pulse’ treatment protocol whereby cells were exposed to test chemical for 4 h, a centrifugation/washout step was performed, and cells were allowed to recover for 20 h. MultiFlow analyses were accomplished at 4 and 24 h. The γ H2AX and phospho-histone H3 biomarkers were found to exhibit distinct differences in terms of their persistence across chemical classes. Unsupervised hierarchical clustering analysis identified three groups. Examination of the compounds within these groups showed one cluster primarily consisting of alkylators that directly target DNA. The other two groups were dominated by non-DNA alkylators and included anti-metabolites, oxidative stress inducers and chemicals that inhibit DNA-processing enzymes. These results are encouraging, as they suggest that a simple follow-up test for in vitro clastogens provides mechanistic insights into their genotoxic activity. This type of information will contribute to improve decision-making and help guide further testing.
A Cohort Study on Prognostic Factors for Laser Interstitial Thermal Therapy Success in Newly Diagnosed Glioblastoma
Authors: Di Long , Wang Christopher P , Shah Ashish H , Eichberg Daniel G , Semonche Alexa M , Sanjurjo Alexander D , Luther Evan M , Jermakowicz Walter J , Komotar Ricardo J , Ivan Michael E
Published: May 2021

BACKGROUND

Laser interstitial thermal therapy (LITT) is a promising approach for cytoreduction of deep-seated gliomas. However, parameters contributing to treatment success remain unclear.

OBJECTIVE

To identify extent of ablation (EOA) and time to chemotherapy (TTC) as predictors of improved overall and progression-free survival (OS, PFS) and suggest laser parameters to achieve optimal EOA.

METHODS

Demographic, clinical, and survival data were collected retrospectively from 20 patients undergoing LITT for newly diagnosed glioblastoma (nGBM). EOA was calculated through magnetic resonance imaging-based volumetric analysis. Kaplan-Meier and multivariate Cox regression were used to examine the relationship between EOA with OS and PFS accounting for covariates (age, isocitrate dehydrogenase-1 (IDH1) mutation, O6-methylguanine-DNA methyltransferase hypermethylation). The effect of laser thermodynamic parameters (power, energy, time) on EOA was identified through linear regression.

RESULTS

Median OS and PFS for the entire cohort were 36.2 and 3.5 mo respectively. Patient's with >70% EOA had significantly improved PFS compared to ≤70% EOA (5.2 vs 2.3 mo, P = .01) and trended toward improved OS (36.2 vs 11 mo, P = .07) on univariate and multivariate analysis. Total laser power was a significant predictor for increased EOA when accounting for preoperative lesion volume (P = .001). Chemotherapy within 16 d of surgery significantly predicted improved PFS compared to delaying chemotherapy (9.4 vs 3.1 mo, P = .009).

CONCLUSION

Increased EOA was a predictor of improved PFS with evidence of a trend toward improved OS in LITT treatment of nGBM. A strategy favoring higher laser power during tumor ablation may achieve optimal EOA. Early transition to chemotherapy after LITT improves PFS.
The Infratemporal Retro-Eustachian Transposition of the Temporoparietal Fascial Flap for Clival Reconstruction After Endoscopic Endonasal Approach: An Anatomic Conceptual Technique
Authors: Cecchini Giulio , Truong Huy Q , Di Biase Francesco , Musio Antonio , Miranda Juan C Fernandez
Published: May 2021

BACKGROUND

Reconstruction after endoscopic endonasal approaches is a key element. Lower clivus reconstruction is difficult and most of the times a pedicled flap is not available. As the complexity and the dimensions of the exposure increase, a reliable reconstruction technique becomes more and more important.

OBJECTIVE

To describe the anatomic and technical nuances of the transposition of the temporoparietal fascial flap for lower clivus reconstruction.

METHODS

A specific temporoparietal fascial flap (TPFF) design and tunneling technique has been studied using 4 head specimens, microscopic and endoscopic surgical techniques, and neuronavigation.

RESULTS

The L-shaped flap offers several advantages. It can be tunneled directly toward the lower clivus passing through the infratemporal fossa.

CONCLUSION

The infratemporal retro-eustachian transposition of an L-shaped TPFF provides a vascularized tissue virtually without dimension limits. This is the only technique that allows the flap to be tunneled directly in the lower clivus with the most vascular portion being at the bottom of the defect. Clinical validation is still required since more issues may become relevant in a real-surgery setting. Though, due to its possible complications, this methodology needs further testing and should not be attempted in less experienced hands.
Two-Level Minimally Invasive Lumbar Laminectomy and Foraminotomy: 2-Dimensional Operative Video
Authors: Srinivasan Ethan S , Crutcher Clifford L , Wang Timothy Y , Grossi Peter M , Than Khoi D
Published: May 2021

Minimally invasive lumbar laminectomies utilize tubular retractors to minimize tissue disturbance, blood loss, and hospital length of stay compared to open operations. Here, we highlight the operative treatment of a 68-yr-old male entailing a 2-level minimally invasive lumbar laminectomy and foraminotomy at L2-L3 and L3-L4. The patient initially presented with symptoms of treatment-refractory lower extremity numbness and limited ambulation. His imaging demonstrated coronal scoliosis and severe lumbar central and foraminal stenosis at L2-L3 and L3-L4, with enlarged spinous processes, laminae, and facets. The patient consented to the procedure and publication of their image. The operation proceeded with the patient in a prone position with paramedian dissection to the lamina through a minimally invasive tubular retractor. Laminectomies and foraminotomies were performed at each level with high-speed drill and a Kerrison rongeur, with care to identify and protect the relevant spinal nerve roots. Postoperatively, the patient reported significantly reduced numbness and improved ambulation, with a well-healed surgical incision notably smaller than those produced in an open operation.
Directional Deep Brain Stimulation Can Target the Thalamic “Sweet Spot” for Improving Neuropathic Dental Pain
Authors: Krüger Marie T , Avecillas-Chasin Josue M , Heran Manraj K S , Naseri Yashar , Sandhu Mini K , Polyhronopoulos Nancy E , Sarai Natasha , Honey Christopher R
Published: May 2021

BACKGROUND

Neuropathic dental pain (NDP) is a chronic pain condition that is notoriously difficult to treat. To date, there are no deep brain stimulation (DBS) studies on this specific pain condition and no optimal target or “sweet spot” has ever been defined.

OBJECTIVE

To determine the optimal thalamic target for improving this condition by utilizing the steering abilities of a directional DBS electrode (Vercise CartesiaTM Model DB-2202-45, Boston Scientific)

METHODS

A literature search and review of our database identified 3 potential thalamic targets. A directional lead was implanted in a patient with NDP and its current steering used to test the effects in each nucleus. The patient reported her pain after 2 wk of stimulation in a prospective randomized blinded trial of one. Quality of life measurements were performed before and after 3 mo on their best setting.

RESULTS

We identified 3 potential nuclei: the centromedian (CM), ventral posterior medial (VPM), and anterior pulvinar. The best results were during VPM stimulation (>90% reduction in pain) and CM stimulation (50% reduction). Following 3 mo of VPM-DBS in combination of lateral CM stimulation, their pain disability index dropped (from 25 to 0) and short form 36 improved (from 67.5 to 90).

CONCLUSION

VPM stimulation in combination with CM stimulation is a promising target for NDP. DBS electrode directionality can be used to test multiple targets and select a patient specific “sweet spot” for NDP treatment.
IIB matrix model and regularized big bang
Authors: Klinkhamer F R
Published: May 2021

The large-N master field of the Lorentzian IIB matrix model can, in principle, give rise to a particular degenerate metric relevant to a regularized big bang. The length parameter of this degenerate metric is then calculated in terms of the IIB-matrix-model length scale.
Implementation of close contact elicitation at the time of COVID-19 testing—Atlanta, GA, October–November 2020
Authors: Yoon Jane C , Prieto Juliana , Shah Sarita , Clark Javarrio , Chamberlain Allison , Holland David P
Published: May 2021

Background

Contact tracing during the Coronavirus Disease 2019 (COVID-19) pandemic in the USA has been met with various challenges. In an attempt to improve the yield of close contact collection, the Fulton County Board of Health implemented a pilot approach to contact elicitation at the time of testing.

Methods

Between October and November 2020, close contacts were elicited from persons under investigation (PUIs) at one COVID-19 testing site in Fulton County, GA. Secure online data collection forms were used to record PUI demographic data, close contact information and reasons for not providing contacts.

Results

Of 1238 PUIs, 48% reported at least one contact. Among the 66 people who tested positive, 16 (24%) reported contacts compared to 578/1165 (50%) who tested negative. PUIs of increasing age were less likely to provide contacts; Black and Hispanic PUIs were also less likely to report any contacts compared to White and Asian PUIs.

Conclusions

Our study revealed that PUIs testing positive were less likely to provide contacts compared to PUIs testing negative. Age and racial differences were also noted in the provision of contacts. Further investigation is needed to understand these discrepancies in order to devise more effective strategies for contact elicitation.
Environmental scanning perspective: The moderating effects of organizational risk and government subsidy in innovation search process
Authors: Bo Qingwen , Zou Bo , Guo Feng
Published: May 2021

From environmental scanning perspective, this study examines the mediated relationship among organizational slack (OS), open innovation search (IS), and high-tech small and medium enterprises (SMEs) performance. We also propose that this mediated relationship is moderated by organizational risk (OR) and government subsidy (GS). We tested our model by using a sample of 244 high-tech SMEs. Our empirical results indicate that open IS partially mediates the positive relationship between OS and SMEs’ performance, and the mediated relationship is strengthened by OR and GS. These findings offer important implications for both SMEs and government to effectively promote firm performance.
Mobility, Inequality, and Beliefs About Distribution and Redistribution
Authors: Wilson George , Roscigno Vincent , Sauer Carsten , Petersen Nick
Published: May 2021

Classic theory has long been interested in mobility, but with limited attention to the implications of intergenerational movement for inequality-specific beliefs. In this article, we introduce a dynamic conception and modeling of the impact of intergenerational occupational mobility on inequality orientations generally and distributive and redistributive beliefs in particular. The diagonal models we employ using 2008–2010 General Social Survey samples—modeling that considers intergenerational occupational origin and destination, and that is replicated on a larger sample across three waves of the GSS—reveal strong conservatizing effects of mobility overall. Those who occupationally fall relative to their parents, although somewhat more progressive by virtue of the downward mobility experience, tend to cling more so to the conservative beliefs characteristic of their higher status origins. Those experiencing mobility gains, in contrast, usually adopt the more conservative orientations of those who they are now surrounded by and in ways that legitimize individual efforts. These patterns are notably pronounced compared to other aspects of one’s job, political affiliation, and status-related attributes; are somewhat stronger among men than women; and differ significantly for Blacks. We elaborate and conclude by highlighting the need for a mobility-centered corrective to sociological understandings of inequality beliefs and how workplace-related experiences in particular shape ideological leanings.
Effects of nocturnal wearing of dentures on the quality of sleep and oral-health-related quality in edentate elders with untreated sleep apnea: a randomized cross-over trial
Authors: Emami Elham , Lavigne Gilles , Feine Jocelyne S , Karp Igor , Rompré Pierre H , Almeida Fernanda R , Huynh Nelly T
Published: May 2021

Study Objectives

This study aims to assess whether the nocturnal wear of dentures has an effect on the quality of sleep and oral-health-related quality of life of the edentulous elderly with untreated sleep apnea.

Methods

A single-blind randomized cross-over design with two sequences and two periods was used. Participants (n = 77) were randomly assigned either to sequence 1 (nocturnal wear followed by nocturnal nonwear of the denture for 30–30 days) or sequence 2 (nocturnal nonwear followed by nocturnal wear of denture for 30–30 days). The primary sleep outcome was the quality of sleep, assessed through sleep fragmentation measured as Apnea–Hypopnea Index (AHI) and respiratory arousal from portable polysomnography. Secondary outcomes were daytime sleepiness, sleep quality (Pittsburgh Sleep Quality Index, PSQI) and oral-health-related quality of life measured by validated questionnaires.

Results

The mean paired difference in AHI scores for the period of wearing versus not wearing dentures at night was small 1.0 event per hour (p = 0.50; 95% confidence interval (CI) = −2.0 to 4.1). The mean respiratory arousal index was higher when wearing dentures at night than when not wearing dentures at night, with a mean paired difference of 2.3 events per hour (p = 0.05; 95% CI = 0.0 to 4.6). No difference in sleepiness and PSQI were noted. Wearing dentures at night resulted in a statistically significantly higher mean score of psychological discomfort when compared to not wearing dentures at night.

Conclusions

The results provide some support to usual practice guidelines to remove dentures at night in edentulous elders suffering from sleep apnea.

Clinical trial registration

NCT01868295.
Criminalized or Medicalized? Examining the Role of Race in Responses to Drug Use
Authors: Lindsay Sadé L , Vuolo Mike
Published: May 2021

Drug policy has shifted from intense criminalization toward reforms that prioritize decarceration and treatment. Despite this shift, little is known about whether support for recent treatment-oriented drug policy is equitable by users’ race and the drug type. Using the opiate and crack cocaine crises as cases, we analyze 400 articles from the New York Times and Washington Post to assess the degree to which the two crises were racialized, criminalized, and medicalized. We find that media coverage medicalized and humanized White people who use opiates, while coverage of crack cocaine focused on criminalization, vilifying Black people who use drugs. We then conduct two vignette experiments (N=308; N=630) to examine whether these racialized frames shape public support for treatment or criminalization. We find the public more likely to support criminalization for Black people, while supporting drug treatment for White people. Respondents are more likely to support drug treatment for heroin use than for crack cocaine. Our findings suggest that support for medicalized approaches to drug use is more likely to occur for White people and drugs linked to White people, while Black people and drugs associated with Black people continue to be perceived as largely amenable to punitive options.
Effect of ‘Candidatus Phytoplasma pruni’ Infection on Sweet Cherry Fruit
Authors: Wright Alice Ann , Shires Madalyn K. , Beaver Christopher , Bishop Garrett , DuPont S. Tianna , Naranjo Ricardo , Harper Scott
Published: May 2021

In sweet cherry (Prunus avium), infection by ‘Candidatus Phytoplasma pruni’ results in small fruit with poor color and taste, rendering the fruit unmarketable. Yet the disease pathology is poorly understood, particularly at the cultivar level. Therefore, in this study we examined the physiological effects of Ca. P. pruni infection across a range of cultivars and locations in eastern Washington. We found that infection could be separated into early and established stages based on pathogen titer, which correlated with disease severity, including fruit size, color, and sugar and metabolite content. Furthermore, we observed that the effects of early-stage infections were largely indistinguishable from healthy, uninfected plants. Cultivar- and location-specific disease outcomes were observed with regard to size, color, sugar content, and citric acid content. This study presents the first in-depth assessment of X-disease symptoms and biochemical content of fruit from commercially grown sweet cherry cultivars known to be infected with Ca. P. pruni.
Rescue of an Infectious cDNA Clone of Barley Yellow Dwarf Virus-GAV
Authors: Hao Xingan , Song Shuang , Zhong Qinrong , Hajano Jamal-U-Ddin , Guo Jie , Wu Yunfeng
Published: May 2021

Barley yellow dwarf virus-GAV (BYDV-GAV) is one of the most prevalent viruses causing yellow dwarf disease in wheat in China. The biology and pathology of BYDV-GAV are well studied; however, gene functions and molecular mechanisms of BYDV-GAV disease development are unclear because of the lack of a reverse genetics system. In this study, a full-length complementary DNA (cDNA) clone of BYDV-GAV was constructed and expressed via Agrobacterium-mediated inoculation of Nicotiana benthamiana. Virions produced by BYDV-GAV in N. benthamiana were transmitted to wheat by an aphid vector after acquisition via a sandwich feeding method. Infectivity of the cDNA clone in wheat was verified via reverse transcription PCR and western blot assays, and the recombinant virus elicited typical reddening symptoms in oats and was transmitted between wheat plants. These results confirm the production of biologically active transmissible virions. Using the BYDV-GAV infectious clone, we demonstrate that viral protein P4 was involved in cell-to-cell movement and stunting symptoms in wheat. This is the first report describing the development of an infectious full-length cDNA clone of BYDV-GAV and provides a useful tool for virus–host–vector interaction studies.
Using Natural Language Processing to Automatically Assess Feedback Quality: Findings From 3 Surgical Residencies
Authors: Ötleş Erkin , Kendrick Daniel E. , Solano Quintin P. , Schuller Mary , Ahle Samantha L. , Eskender Mickyas H. , Carnes Emily , George Brian C.
Published: May 2021

Purpose

Learning is markedly improved with high-quality feedback, yet assuring the quality of feedback is difficult to achieve at scale. Natural language processing (NLP) algorithms may be useful in this context as they can automatically classify large volumes of narrative data. However, it is unknown if NLP models can accurately evaluate surgical trainee feedback. This study evaluated which NLP techniques best classify the quality of surgical trainee formative feedback recorded as part of a workplace assessment.

Method

During the 2016–2017 academic year, the SIMPL (Society for Improving Medical Professional Learning) app was used to record operative performance narrative feedback for residents at 3 university-based general surgery residency training programs. Feedback comments were collected for a sample of residents representing all 5 postgraduate year levels and coded for quality. In May 2019, the coded comments were then used to train NLP models to automatically classify the quality of feedback across 4 categories (effective, mediocre, ineffective, or other). Models included support vector machines (SVM), logistic regression, gradient boosted trees, naive Bayes, and random forests. The primary outcome was mean classification accuracy.

Results

The authors manually coded the quality of 600 recorded feedback comments. Those data were used to train NLP models to automatically classify the quality of feedback across 4 categories. The NLP model using an SVM algorithm yielded a maximum mean accuracy of 0.64 (standard deviation, 0.01). When the classification task was modified to distinguish only high-quality vs low-quality feedback, maximum mean accuracy was 0.83, again with SVM.

Conclusions

To the authors’ knowledge, this is the first study to examine the use of NLP for classifying feedback quality. SVM NLP models demonstrated the ability to automatically classify the quality of surgical trainee evaluations. Larger training datasets would likely further increase accuracy.
Efficacy and Safety of LCZ696 for Short-term Management of Essential Hypertension Compared With ARBs: A Meta-analysis of Randomized Controlled Trials
Authors: Yang Shuai , Zhang Hongzhou , Yang Pingping , Wang Chenxi , Wu Qinghua
Published: May 2021

Whether LCZ696 (neprilysin inhibitor + valsartan) has greater advantages of blood pressure (BP) lowering than angiotensin II type 1 receptor blockers (ARBs) is unclear. To provide more detailed information about the benefits of LCZ696, we conducted a meta-analysis to evaluate the efficacy and safety of LCZ696 for short-term management of hypertension compared with ARBs. We searched PubMed, EMBASE, the Cochrane Library, and ClinicalTrials.gov, using relevant keywords. We used a random or fixed effects model to calculate the weighted mean difference (WMD) of changes in BP and the risk ratio (RR) for BP control rates and adverse events (AEs). In this meta-analysis, 9 studies were incorporated. Compared with ARBs, LCZ696 revealed a significant reduction in mean sitting systolic BP [msSBP; WMD −4.79 mm Hg; 95% confidence interval (CI): −5.46 to −4.11 mm Hg], mean sitting diastolic BP (msDBP; WMD −2.12 mm Hg; 95% CI: −2.53 to −1.71 mm Hg), mean sitting pulse pressure (msPP; WMD −2.79 mm Hg; 95% CI: −3.52 to −2.07 mm Hg), and mean ambulatory pulse pressure (maPP; WMD −2.96 mm Hg; 95% CI: −3.35 to −2.57 mm Hg). LCZ696 had a higher BP control rate than ARBs (OR = 1.55; 95% CI: 1.39 to 1.73). There was no significant difference between LCZ696 and ARBs in the incidence of AEs (RR = 1.10; 95% CI: 0.96 to 1.25) and discontinuations because of AEs (RR = 0.97; 95% CI: 0.54 to 1.32). Overall, in short-term treatment, LCZ696 has greater advantages of antihypertensive efficacy and the safety is not inferior to ARBs. Further long-term studies are required to rule out the potential risks of beta amyloid accumulation and the potential for Alzheimer's disease.
Conceptual Framework for Incontinence-Associated Dermatitis Based on Scoping Review and Expert Consensus Process
Authors: Rodríguez-Palma Manuel , Verdú-Soriano José , Soldevilla-Agreda J. Javier , Pancorbo-Hidalgo Pedro L. , García-Fernández Francisco Pedro
Published: May 2021

Incontinence-associated dermatitis (IAD) has been studied over the last decades, but gaps in the knowledge related to its identification, etiological agents, and risk factors remain. We carried out a scoping review about IAD that included systematic reviews, experimental, and observational studies about IAD and its potential risk factors. We retrieved 24 articles that described 100 potential risk factors and which were synthesized by the authors and proposed to a panel of experts. Panelists used a structured process of consensus development to create a conceptual framework of factors associated with IAD. This framework proposes that liquid fecal material, when combined with exposure to urine and stool, and bacterial contaminated urine are etiological factors for development of IAD. The framework also proposes 2 pathophysiological mechanisms and 8 main risk factors for IAD development. The proposed model could improve the quality of care for patients with or at risk of IAD, assisting healthcare professionals to identify at-risk patients, diagnose the type of lesion, and establish adequate and effective prevention and treatment measures.
Human convalescent plasma protects K18-hACE2 mice against severe respiratory disease
Authors: Golden Joseph W. , Zeng Xiankun , Cline Curtis R. , Garrison Aura R. , White Lauren E. , Fitzpatrick Collin J. , Kwilas Steven A. , Bowling Philip A. , Fiallos Jimmy O. , Moore Joshua L. , Sifford Willie B. , Ricks Keersten M. , Mucker Eric M. , Smith Jeffrey M. , Hooper Jay W.
Published: May 2021

SARS-CoV-2 is the causative agent of COVID-19 and human infections have resulted in a global health emergency. Small animal models that reproduce key elements of SARS-CoV-2 human infections are needed to rigorously screen candidate drugs to mitigate severe disease and prevent the spread of SARS-CoV-2. We and others have reported that transgenic mice expressing the human angiotensin-converting enzyme 2 (hACE2) viral receptor under the control of the Keratin 18 (K18) promoter develop severe and lethal respiratory disease subsequent to SARS-CoV-2 intranasal challenge. Here we report that some infected mice that survive challenge have residual pulmonary damages and persistent brain infection on day 28 post-infection despite the presence of anti-SARS-COV-2 neutralizing antibodies. Because of the hypersensitivity of K18-hACE2 mice to SARS-CoV-2 and the propensity of virus to infect the brain, we sought to determine if anti-infective biologics could protect against disease in this model system. We demonstrate that anti-SARS-CoV-2 human convalescent plasma protects K18-hACE2 against severe disease. All control mice succumbed to disease by day 7; however, all treated mice survived infection without observable signs of disease. In marked contrast to control mice, viral antigen and lesions were reduced or absent from lungs and absent in brains of antibody-treated mice. Our findings support the use of K18-hACE2 mice for protective efficacy studies of anti-SARS-CoV-2 medical countermeasures (MCMs). They also support the use of this system to study SARS-CoV-2 persistence and host recovery.