bluuebunny/crossref_metadata_2025 huggingface dataset:
An Adaptive and Evidence-Based Approach to Building and Retaining Gender Diversity within a University Forestry Education Program: A Case Study of SWIFT
Authors: Crandall Mindy S , Costanza Kara K L , Zukswert Jenna M , Kenefic Laura S , Leahy Jessica E
Published: February 2020

Abstract

Retaining women in forestry and other science, technology, engineering, and mathematics fields is a challenge. University education represents a critical point along the forestry pipeline in which women might leave the profession. Concerned with the low number of women graduating with bachelor’s degrees in forestry from the University of Maine’s School of Forest Resources, a group of faculty and students formed Supporting Women in Forestry Today (SWIFT) in 2016. An organization guided by literature on improving gender diversity in the workplace, SWIFT has taken an adaptive and evidence-based approach while hosting events throughout each academic year. Surveys indicate that SWIFT has been effective at helping participants increase awareness of gender-related issues, gain strategies, and develop connections. Although challenges still exist for women in forestry, this case study suggests that SWIFT is an effective model that could be used elsewhere to support the retention of women in the forestry profession.
Elementary cellular automata and self-referential paradoxes
Authors: HSIUNG MING
Published: February 2020

We associate an elementary cellular automaton with a set of self-referential sentences, whose revision process is exactly the evolution process of that automaton. A simple but useful result of this connection is that a set of self-referential sentences is paradoxical, iff (the evolution process for) the cellular automaton in question has no fixed points. We sort out several distinct kinds of paradoxes by the existence and features of the fixed points of their corresponding automata. They are finite homogeneous paradoxes and infinite homogeneous paradoxes. In some weaker sense, we will also introduce no-no-sort paradoxes and virtual paradoxes. The introduction of these paradoxes, in turn, leads to a new classification of the cellular automata.
On the origin of dust in galaxy clusters at low-to-intermediate redshift
Authors: Gjergo Eda , Palla Marco , Matteucci Francesca , Lacchin Elena , Biviano Andrea , Fan Xilong
Published: February 2020

Stacked analyses of galaxy clusters at low-to-intermediate redshift show signatures attributable to dust, but the origin of this dust is uncertain. We test the hypothesis that the bulk of cluster dust derives from galaxy ejecta. To do so, we employ dust abundances obtained from detailed chemical evolution models of galaxies. We integrate the dust abundances over cluster luminosity functions (one-slope and two-slope Schechter functions). We consider both a hierarchical scenario of galaxy formation and an independent evolution of the three main galactic morphologies: elliptical/S0, spiral and irregular. We separate the dust residing within galaxies from the dust ejected in the intracluster medium. To the latter, we apply thermal sputtering. The model results are compared to low-to-intermediate redshift observations of dust masses. We find that in any of the considered scenarios, elliptical/S0 galaxies contribute negligibly to the present-time intracluster dust, despite producing the majority of gas-phase metals in galaxy clusters. Spiral galaxies, instead, provide both the bulk of the spatially unresolved dust and of the dust ejected into the intracluster medium. The total dust-to-gas mass ratio in galaxy clusters amounts to 10−4, while the intracluster medium dust-to-gas mass ratio amounts to 10−6 at most. These dust abundances are consistent with the estimates of cluster observations at 0.2 < z < 1. We propose that galactic sources, spiral galaxies in particular, are the major contributors to the cluster dust budget.
SnowPac: a multiscale cubic B-spline wavelet compressor for astronomical images
Authors: Pulido Jesus , Zheng Caixia , Thorman Paul , Hamann Bernd
Published: February 2020

As more advanced and complex survey telescopes are developed, the size and scale of data being captured grows at increasing rates. Across various domains, data compression through wavelets has enabled the reduction of data size and increase in computation efficiency. In this paper, we provide qualitative and quantitative tests of a new wavelet-based image compression method compared against the current standard for astronomical images. The analysis is improved by making use of state-of-the-art object detection systems to accurately measure the impact of the compression. We find that a combination of lossy wavelet-based methods, efficient quantization, and lossless dictionary compressors can preserve up to 98 per cent of astronomical objects at a 10:1 compression ratio. This significant reduction in file size also preserves astronomical object properties better than existing methods. These methods help further reduce future workloads for image-heavy processing pipelines.
Absolute parameters of three southern eclipsing binaries: DQ Car, BK Ind, and V4396 Sgr
Authors: Sürgit Derya , Erdem Ahmet , Engelbrecht Chris A , Marang Fred
Published: February 2020

We present combined photometric and spectroscopic analyses of the three southern eclipsing binary stars: DQ Car, BK Ind, and V4396 Sgr. Radial velocity curves of these three systems were obtained at the South African Astronomical Observatory, and their light curves from the available data bases and surveys were used for the analysis. 75 new times of minima for these three eclipsing binaries were derived, and their ephemerides were updated. Only the O–C diagram of DQ Car indicates a cyclical variation, which was interpreted in terms of the light-time effect due to a third body in the system. Our final models describe these three systems as Algol-like binary stars with detached configurations. The masses and radii were found to be M1 = 1.86(±0.17) M⊙, R1 = 1.63(±0.06) R⊙ and M2 = 1.74(±0.17) M⊙, R2 = 1.52(±0.07) R⊙ for the primary and secondary components of DQ Car; M1 = 1.16(±0.05) M⊙, R1 = 1.33(±0.03) R⊙ and M2 = 0.98(±0.04) M⊙, R2 = 1.00(±0.03) R⊙ for BK Ind; and M1 = 3.14(±0.22) M⊙, R1 = 3.00(±0.09) R⊙ and M2 = 3.13(±0.24) M⊙, R2 = 2.40(±0.08) R⊙ for V4396 Sgr, respectively. The distances to DQ Car, BK Ind, and V4396 Sgr were derived to be 701(±50), 285(±20), and 414(±30) pc from the distance modulus formula, taking into account interstellar extinction. The evolutionary status of these three systems was also studied. It has been found that the components of DQ Car are very young stars at the age of ∼25 Myr and those of BK Ind and V4396 Sgr are evolved main-sequence stars at the ages of ∼2.69 Gyr and ∼204 Myr, respectively.
The origin of dust in galaxies across cosmic time
Authors: Triani Dian P , Sinha Manodeep , Croton Darren J , Pacifici Camilla , Dwek Eli
Published: February 2020

We study the dust evolution in galaxies by implementing a detailed dust prescription in the SAGE semi-analytical model (SAM) for galaxy formation. The new model, called Dusty SAGE, follows the condensation of dust in the ejecta of Type II supernovae and asymptotic giant branch stars, grain growth in the dense molecular clouds, destruction by supernovae shocks, and the removal of dust from the interstellar medium (ISM) by star formation, reheating, inflows, and outflows. Our model successfully reproduces the observed dust mass function at redshift z = 0 and the observed scaling relations for dust across a wide range of redshifts. We find that the dust mass content in the present Universe is mainly produced via grain growth in the ISM. By contrast, in the early Universe, the primary production mechanism for dust is the condensation in stellar ejecta. The shift of the significant production channel for dust characterizes the scaling relations of dust-to-gas (DTG) and dust-to-metal (DTM) ratios. In galaxies where the grain growth dominates, we find positive correlations for DTG and DTM ratios with both metallicity and stellar mass. On the other hand, in galaxies where dust is produced primarily via condensation, we find negative or no correlation for DTM and DTG ratios with either metallicity or stellar mass. In agreement with observation showing that the circumgalactic medium contains more dust than the ISM, our model also shows the same trend for z < 4. Our SAM is publicly available at https://github.com/dptriani/dusty-sage.
On the activity of comets: understanding the gas and dust emission from comet 67/Churyumov–Gerasimenko’s south-pole region during perihelion
Authors: Gundlach B , Fulle M , Blum J
Published: February 2020

When comets approach the Sun, their surface is heated and the volatile species start to sublimate. Due to the increasing gas pressure, dust is ejected off the surface, which can be observed as cometary coma, dust tail, and trail. However, the underlying physical processes are not fully understood. Using state-of-the-art results for the transport of heat and gas as well as of the mechanical properties of cometary matter, we intend to describe the activity pattern of comets when they approach the Sun. We developed a novel thermophysical model to simulate the dust ejection from comet 67/Churyumov–Gerasimenko’s south-pole region at perihelion. Based on the input parameters, this model computes the sub-surface temperature profile, the pressure build-up, and the redistribution of volatiles inside the cometary sub-surface region and provides mass-loss rates of dust and gas as well as typical sizes and ice content of the ejected dust chunks. Our thermophysical model allows for continuous gas and dust ejection from the Southern hemisphere of comet 67/Churyumov–Gerasimenko at perihelion. We find that the model output is in general agreement with the observed Rosetta data. The sublimation of CO2 ice drives the ejection of very large ($\gtrsim 10\, \mathrm{cm}$) chunks, which contain $10\, {{\ \rm per\ cent}}$ to $90 \, {{\ \rm per\ cent}}$ of the initial water–ice content. In contrast, the outgassing of H2O ice causes the lift-off of small clusters of dust aggregates, which contain no ice.
Supernova feedback and the energy deposition in molecular clouds
Authors: Lucas William E , Bonnell Ian A , Dale James E
Published: February 2020

Feedback from supernovae is often invoked as an important process in limiting star formation, removing gas from galaxies and, hence, as a determining process in galaxy formation. Here, we report on numerical simulations, investigating the interaction between supernova explosions and the natal molecular cloud. We also consider the cases with and without previous feedback from the high-mass star in the form of ionizing radiation and stellar winds. The supernova is able to find weak points in the cloud and creates channels through which it can escape, leaving much of the well-shielded cloud largely unaffected. This effect is increased when the channels are preexisting due to the effects of previous stellar feedback. The expanding supernova deposits its energy in the gas that is in these exposed channels, and, hence, sweeps up less mass when feedback has already occurred, resulting in faster outflows with less radiative losses. The full impact of the supernova explosion is then able to impact the larger scale of the galaxy in which it abides. We conclude that supernova explosions have only moderate effects on their dense natal environments but that with preexisting feedback, the energetic effects of the supernova are able to escape and affect the wider scale medium of the galaxy.
Interacting galaxies in the IllustrisTNG simulations – II: star formation in the post-merger stage
Authors: Hani Maan H , Gosain Hayman , Ellison Sara L , Patton David R , Torrey Paul
Published: February 2020

Galaxy mergers are a major evolutionary transformation whose effects are borne out by a plethora of observations and numerical simulations. However, most previous simulations have used idealized, isolated, binary mergers and there has not been significant progress on studying statistical samples of galaxy mergers in large cosmological simulations. We present a sample of 27 691 post-merger (PM) galaxies (0c ≤ z ≤ 1) identified from IllustrisTNG: a cosmological, large box, magnetohydrodynamical simulation suite. The PM sample spans a wide range of merger and galaxy properties (M⋆, μ, fgas). We demonstrate that star-forming (SF) PMs exhibit enhanced star formation rates (SFRs) on average by a factor of ∼2, while the passive PMs show no statistical enhancement. We find that the SFR enhancements: (1) show no dependence on redshift, (2) anticorrelate with the PM’s stellar mass, and (3) correlate with the gas fraction of the PM’s progenitors. However, SF PMs show stronger enhancements which may indicate other processes being at play (e.g. gas phase, feedback efficiency). Although the SFR enhancement correlates mildly with the merger mass ratio, the more abundant minor mergers (0.1 ≤ μ < 0.3) still contribute ${\sim}50{{\ \rm per\ cent}}$ of the total SFR enhancement. By tracing the PM sample forward in time, we find that galaxy mergers can drive significant SFR enhancements which decay over ∼0.5 Gyr independent of the merger mass ratio, although the decay time-scale is dependent on the simulation resolution. The strongest merger-driven starburst galaxies evolve to be passive/quenched on faster time-scales than their controls.
Scoliosis Research Society-Schwab Grade 6 Osteotomy for Severe Congenital Angular Kyphoscoliosis: An Analysis of 17 Cases With a Minimum 2-Year Follow-up
Authors: Shi Bo , Shi Benlong , Liu Dun , Li Yang , Xia Sanqiang , Sun Xu , Liu Zhen , Qian Bangping , Zhu Zezhang , Qiu Yong
Published: February 2020

BACKGROUND

For some patients with severe congenital angular kyphoscoliosis (SCAK), 1-level vertebral column resection is insufficient and the Scoliosis Research Society (SRS)-Schwab Grade 6 osteotomy may be necessary. However, the indications and clinical outcomes of SRS-Schwab Grade 6 osteotomy in patients with SCAK have not been investigated in depth.

OBJECTIVE

To investigate the middle-term radiographic and clinical outcomes, and to evaluate the safety of this high technique-demanding procedure.

METHODS

Patients with SCAK undergoing SRS-Schwab Grade 6 osteotomy from 2005 to 2016 followed up at least 2 yr were retrospectively reviewed. The potential indications of SRS-Schwab Grade 6 osteotomy were analyzed. The coronal Cobb angle, segmental kyphosis (SK), deformity angular ratio (DAR), coronal balance, and sagittal vertical axis (SVA) were measured in the preoperative, postoperative, and final follow-up. The intraoperative and postoperative complications were recorded.

RESULTS

A total of 17 patients with SCAK (10 M and 7F) were included, and the mean follow-up was 30.8 ± 16.4 mo. The indications of SRS-Schwab Grade 6 osteotomy were as follows: multiple “pushed-out” hemivertebrae (13, 76.5%) and multilevel anterior block (4, 23.5%). Compared with preoperation, the coronal Cobb angle, SK and SVA at postoperation were significantly improved (P < .05 for all). The mean total DAR was 33.4 ± 9.9 at preoperation. Three patients were found to have postoperative neurological deficit. Rod breakage occurred in 3 patients at 15- to 48-mo follow-up, and revision surgeries were performed. At the last follow-up, firm bony fusion was observed in all patients.

CONCLUSION

The technique-demanding SRS-Schwab Grade 6 osteotomy, if well indicated, could provide satisfying correction of the SCAK deformity.
Effects of proactive and rescue enteral tube feedings on weight change in children undergoing treatment for high-grade CNS tumors
Authors: Bendelsmith Charles R , Linabery Amy M , Nickel Amanda J , Laquere Rachel M , Ingram Katherine M , Hansen Melissa B , Pape-Blabolil Julie A , Skrypek Mary M , Bendel Anne E
Published: February 2020

Background

Children with high-grade CNS cancers frequently experience malnutrition during treatment. We assessed the effects of proactive enteral tube (ET) placement/enteral tube feedings (ETF) on weight in infants/children with high-grade CNS tumors treated with aggressive chemotherapy.

Methods

We conducted a retrospective study of patients age 0 to 19 years treated for new high-grade CNS tumors between 2002 and 2017 at a tertiary pediatric hospital system. Patients underwent placement of proactive ET (≤ 31 days postdiagnosis; n = 45), rescue ET (> 31 days, due to weight loss; n = 9), or no ET (n = 18). Most received surgically placed ET (98%), with percutaneous endoscopic gastrojejunostomy or gastrojejunostomy tubes favored to allow jejunal feeding. The majority of patients with ET used ETF (91%). Using mixed-effects regression models, we examined differences in mean weights between ET/ETF groups across the first year of treatment. We also evaluated observed weight changes.

Results

All infants (n = 22, median age, 1.5 years) had proactive ET placed and 21 of 22 used proactive ETF. Infants showed an initial increase in mean percentage weight change that eventually leveled off, for an estimated increase of 10.4% over the year. For the pediatric cohort (n = 50, median, 8.1 years), those receiving proactive ETF experienced weight increases (+9.9%), those with rescue ETF experienced an initial decline and eventually rebounded for no net change (0.0%), and those with no ETF demonstrated an initial decline that persisted (–11.9%; Pinteraction < .001). Analysis of observed weights revealed nearly identical patterns.

Conclusions

Proactive ETF was effective at maintaining weight and/or facilitating weight gain over the first year of treatment and was acceptable to patients/families.
Predicting future dynamics from short-term time series using an Anticipated Learning Machine
Authors: Chen Chuan , Li Rui , Shu Lin , He Zhiyu , Wang Jining , Zhang Chengming , Ma Huanfei , Aihara Kazuyuki , Chen Luonan
Published: February 2020

Predicting time series has significant practical applications over different disciplines. Here, we propose an Anticipated Learning Machine (ALM) to achieve precise future-state predictions based on short-term but high-dimensional data. From non-linear dynamical systems theory, we show that ALM can transform recent correlation/spatial information of high-dimensional variables into future dynamical/temporal information of any target variable, thereby overcoming the small-sample problem and achieving multistep-ahead predictions. Since the training samples generated from high-dimensional data also include information of the unknown future values of the target variable, it is called anticipated learning. Extensive experiments on real-world data demonstrate significantly superior performances of ALM over all of the existing 12 methods. In contrast to traditional statistics-based machine learning, ALM is based on non-linear dynamics, thus opening a new way for dynamics-based machine learning.
Biotic vs. abiotic forcing on plankton assemblages varies with season and size class in a large temperate estuary
Authors: Rollwagen-Bollens Gretchen , Bollens Stephen , Dexter Eric , Cordell Jeffery
Published: February 2020

Large river estuaries experience multiple anthropogenic stressors. Understanding plankton community dynamics in these estuaries provides insights into the patterns of natural variability and effects of human activity. We undertook a 2-year study in the Columbia River Estuary to assess the potential impacts of abiotic and biotic factors on planktonic community structure over multiple time scales. We measured microplankton and zooplankton abundance, biomass and composition monthly, concurrent with measurements of chlorophyll a, nutrient concentrations, temperature and salinity, from a dock in the lower estuary. We then statistically assessed the associations among the abundances of planktonic groups and environmental and biological factors. During the late spring high flow period of both years, the lower estuary was dominated by freshwater and low salinity-adapted planktonic taxa, and zooplankton grazers were more strongly associated with the autotroph-dominated microplankton assemblage than abiotic factors. During the early winter period of higher salinity and lower flow, nutrient (P) availability exerted a strong influence on microplankton taxa, while only temperature and upwelling strength were associated with the zooplankton assemblage. Our results indicate that the relative influence of biotic (grazers) and abiotic (salinity, flow, nutrients and upwelling) factors varies seasonally and inter-annually, and among different size classes in the estuarine food web.
The Ecology of Emergency Management Work in the Digital Age
Authors: Misra Shalini , Roberts Patrick , Rhodes Matthew
Published: February 2020

This research uses an abductive research strategy and person–environment (P–E) fit as a frame to understand: (1) how digital technologies have transformed emergency managerial work; and (2) managers’ cognitive, affective, and behavioral responses to these structural and organizational transformations. Interviews of county-level emergency managers in the United States reveal that pervasive computing environments have resulted in intensification of interchanges and new patterns of relationships with public, public officials, and other agencies that have changed the power balance between the public and emergency managers. We uncover points of tension between managers’ personal attributes and their organizational and broader environmental conditions. We articulate two mechanisms, optimization and passive adaptation, by which emergency managers and their immediate and broader socio-cultural and political environments interact to influence psychological and behavioral outcomes. On the one hand, role ambiguity, role conflict, and diminished agency indicate passive adaptation to structural transformation. On the other, predictive uses of technology, novel organizational routines, and new collaborative relationships suggest managers’ efforts at optimization. We develop a social ecological framework for P–E fit that elucidates the contextual factors most relevant to understanding public managerial responses to technological change and links antecedent conditions to the processes and outcomes of P–E incongruence.
Income Segregation and Intergenerational Mobility Across Colleges in the United States*
Authors: Chetty Raj , Friedman John N , Saez Emmanuel , Turner Nicholas , Yagan Danny
Published: February 2020

We construct publicly available statistics on parents’ incomes and students’ earnings outcomes for each college in the United States using deidentified data from tax records. These statistics reveal that the degree of parental income segregation across colleges is very high, similar to that across neighborhoods. Differences in postcollege earnings between children from low- and high-income families are much smaller among students who attend the same college than across colleges. Colleges with the best earnings outcomes predominantly enroll students from high-income families, although a few mid-tier public colleges have both low parent income levels and high student earnings. Linking these income data to SAT and ACT scores, we simulate how changes in the allocation of students to colleges affect segregation and intergenerational mobility. Equalizing application, admission, and matriculation rates across parental income groups conditional on test scores would reduce segregation substantially, primarily by increasing the representation of middle-class students at more selective colleges. However, it would have little effect on the fraction of low-income students at elite private colleges because there are relatively few students from low-income families with sufficiently high SAT/ACT scores. Differences in parental income distributions across colleges could be eliminated by giving low- and middle-income students a sliding-scale preference in the application and admissions process similar to that implicitly given to legacy students at elite private colleges. Assuming that 80% of observational differences in students’ earnings conditional on test scores, race, and parental income are due to colleges’ causal effects—a strong assumption, but one consistent with prior work—such changes could reduce intergenerational income persistence among college students by about 25%. We conclude that changing how students are allocated to colleges could substantially reduce segregation and increase intergenerational mobility, even without changing colleges’ educational programs.
Image Conditions for Elliptical-Coordinate Separation-of-Variables Acoustic Multiple Scattering Models with Perfectly Reflecting Flat Boundaries: Application to in Situ Tunable Noise Barriers
Authors: Shin Ho-Chul
Published: February 2020

Two-dimensional time-harmonic multiple scattering problems are addressed for a finite number of elliptical objects placed in wedge-shaped acoustic domains including half-plane and right-angled corners. The method of separation of variables in conjunction with the addition theorems is employed in the elliptical coordinates. The wavefunctions are represented in terms of radial and angular Mathieu functions. The method of images is applied to consider the effect of the infinitely long flat boundaries which are perfectly reflecting: either rigid or pressure release. The wedge angle is $\pi/n$ rad with integer $n$; image ellipses must be appropriately rotated to realise the mirror reflection. Then, the ‘image conditions’ are developed to reduce the number of unknowns by expressing the unknown expansion coefficients of image scattered fields in terms of real counterparts. Use of image conditions, therefore, leads to the $4n^2$-fold reduction in the size of a matrix for direct solvers and $2n$-times faster computation in building the system of linear equations than the approach without using them. Multiple scattering models using image conditions are formulated for rigid, pressure release and fluid ellipses under either plane- or cylindrical-wave incidence, and are numerically validated by the boundary element method. Furthermore, potential applications are presented: arrays of elliptically shaped scatterers make in situ tunable noise barriers by rotating scatterers. Finally, polar-coordinate image conditions (for circular objects) are also discussed when coordinates local to circles are also rotated. In Appendix, analytic formulae are provided, which permits the elliptical-coordinate addition theorems used in this article to be calculated by summation instead of numerical integration.
Impacts of subclinical hypocalcemia on physiological, metabolic, and productive responses of Holstein × Gir dairy cows1
Authors: Rodrigues Rodrigo , Cooke Reinaldo F , Ferreira Hingryd A O , Florido Renato R , Camargo Victoria , de Godoy Hirys O , Bruni Giulia A , Vasconcelos José L M
Published: February 2020

This study compared physiological and productive parameters in ¾ Holstein × ¼ Gir dairy cows diagnosed or not with subclinical hypocalcemia (SCH) during early lactation. Nonlactating, multiparous cows (n = 32) were enrolled in this experiment 21 d prior to expected date of calving. Cows were maintained in a single pen with ad libitum access to corn silage before calving and received a limit-fed prepartum concentrate. Cow body weight (BW) and body condition score (BCS) were recorded weekly, and blood samples were collected on days −21, −14, −9, −6, and −3 relative to expected calving. After calving (day 0), cows were managed in a single pen with ad libitum access to a total mixed ration, and were milked twice daily. Cow BW and BCS were recorded upon calving and then weekly. Milk production was recorded daily and milk samples collected weekly until 30 d in milk (DIM). Blood was collected during the first 5 DIM, and at 6, 9, 16, 23, and 30 DIM. Cows were classified with SCH when mean total serum Ca during the first 5 DIM was ≤2.125 mmol/L. Cows diagnosed with SCH (n = 11) had less (P ≤ 0.04) mean BCS (2.85 vs. 3.07; SEM = 0.07) and less concentrations of serum insulin (0.396 vs. 0.738 ppmol/L; SEM = 0.115) and insulin-like growth factor I (35.9 vs. 57.9 ng/mL; SEM = 4.2), and these outcomes were noted since 21 d prior to expected calving. Cows diagnosed with SCH had greater (P < 0.01) serum concentrations of cortisol at calving (30.2 vs. 22.4 ng/mL; SEM = 2.0), serum haptoglobin at 3 and 6 DIM (0.453 vs. 0.280 mg/mL on day 3 and 0.352 vs. 0.142 mg/mL on day 6; SEM = 0.046), and tended (P = 0.09) to have greater mean concentrations of nonesterified fatty acids from calving to 30 DIM (0.368 vs. 0.304 μEq/L; SEM = 0.026). No differences were detected (P ≥ 0.41) for cow BW and milk production. Cows diagnosed with SCH had less (P = 0.05) mean concentrations of milk total solids (13.2 vs. 13.8 %; SEM = 0.21), tended to have less (P ≤ 0.10) mean concentrations of milk fat (4.34 vs. 4.81 %; SEM = 0.20), protein (3.31 vs. 3.45 %; SEM = 0.05), and lactose (4.45 vs. 4.55 %; SEM = 0.04), and had greater (P = 0.02) milk somatic cell count during the initial 14 DIM (504 vs. 140 cells/μL; SEM = 90). Collectively, Holstein × Gir cows diagnosed with SCH upon calving had altered periparturient physiological parameters denoting reduced energy nutritional, increased milk somatic cell count, and less concentration of milk components during early lactation compared with normocalcemic cows.
Mechanism-Driven Read-Across of Chemical Hepatotoxicants Based on Chemical Structures and Biological Data
Authors: Zhao Linlin , Russo Daniel P , Wang Wenyi , Aleksunes Lauren M , Zhu Hao
Published: February 2020

Hepatotoxicity is a leading cause of attrition in the drug development process. Traditional preclinical and clinical studies to evaluate hepatotoxicity liabilities are expensive and time consuming. With the advent of critical advancements in high-throughput screening, there has been a rapid accumulation of in vitro toxicity data available to inform the risk assessment of new pharmaceuticals and chemicals. To this end, we curated and merged all available in vivo hepatotoxicity data obtained from the literature and public resources, which yielded a comprehensive database of 4089 compounds that includes hepatotoxicity classifications. After dividing the original database of chemicals into modeling and test sets, PubChem assay data were automatically extracted using an in-house data mining tool and clustered based on relationships between structural fragments and cellular responses in in vitro assays. The resultant PubChem assay clusters were further investigated. During the cross-validation procedure, the biological data obtained from several assay clusters exhibited high predictivity of hepatotoxicity and these assays were selected to evaluate the test set compounds. The read-across results indicated that if a new compound contained specific identified chemical fragments (ie, Molecular Initiating Event) and showed active responses in the relevant selected PubChem assays, there was potential for the chemical to be hepatotoxic in vivo. Furthermore, several mechanisms that might contribute to toxicity were derived from the modeling results including alterations in nuclear receptor signaling and inhibition of DNA repair. This modeling strategy can be further applied to the investigation of other complex chemical toxicity phenomena (eg, developmental and reproductive toxicities) as well as drug efficacy.
Severe Hypoxemia Prevents Spontaneous and Naloxone-induced Breathing Recovery after Fentanyl Overdose in Awake and Sedated Rats
Authors: Haouzi Philippe , Guck Daniel , McCann Marissa , Sternick Molly , Sonobe Takashi , Tubbs Nicole
Published: February 2020

Background

As severe acute hypoxemia produces a rapid inhibition of the respiratory neuronal activity through a nonopioid mechanism, we have investigated in adult rats the effects of hypoxemia after fentanyl overdose-induced apnea on (1) autoresuscitation and (2) the antidotal effects of naloxone.

Methods

In nonsedated rats, the breath-by-breath ventilatory and pulmonary gas exchange response to fentanyl overdose (300 µg · kg-1 · min-1 iv in 1 min) was determined in an open flow plethysmograph. The effects of inhaling air (nine rats) or a hypoxic mixture (fractional inspired oxygen tension between 7.3 and 11.3%, eight rats) on the ability to recover a spontaneous breathing rhythm and on the effects of naloxone (2 mg · kg-1) were investigated. In addition, arterial blood gases, arterial blood pressure, ventilation, and pulmonary gas exchange were determined in spontaneously breathing tracheostomized urethane-anesthetized rats in response to (1) fentanyl-induced hypoventilation (7 rats), (2) fentanyl-induced apnea (10 rats) in air and hyperoxia, and (3) isolated anoxic exposure (4 rats). Data are expressed as median and range.

Results

In air-breathing nonsedated rats, fentanyl produced an apnea within 14 s (12 to 29 s). A spontaneous rhythmic activity always resumed after 85.4 s (33 to 141 s) consisting of a persistent low tidal volume and slow frequency rhythmic activity that rescued all animals. Naloxone, 10 min later, immediately restored the baseline level of ventilation. At fractional inspired oxygen tension less than 10%, fentanyl-induced apnea was irreversible despite a transient gasping pattern; the administration of naloxone had no effects. In sedated rats, when Pao
2 reached 16 mmHg during fentanyl-induced apnea, no spontaneous recovery of breathing occurred and naloxone had no rescuing effect, despite circulation being maintained.

Conclusions

Hypoxia-induced ventilatory depression during fentanyl induced apnea (1) opposes the spontaneous emergence of a respiratory rhythm, which would have rescued the animals otherwise, and (2) prevents the effects of high dose naloxone.

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Dynamics of Ketamine-induced Loss and Return of Consciousness across Primate Neocortex
Authors: Ballesteros Jesus J. , Huang Pamela , Patel Shaun R. , Eskandar Emad N. , Ishizawa Yumiko
Published: February 2020

Background

Ketamine is a noncompetitive N-methyl-d-aspartate antagonist and is known for unique electrophysiologic profiles in electroencephalography. However, the mechanisms of ketamine-induced unconsciousness are not clearly understood. The authors have investigated neuronal dynamics of ketamine-induced loss and return of consciousness and how multisensory processing is modified in the primate neocortex.

Methods

The authors performed intracortical recordings of local field potentials and single unit activity during ketamine-induced altered states of consciousness in a somatosensory and ventral premotor network. The animals were trained to perform a button holding task to indicate alertness. Air puff to face or sound was randomly delivered in each trial regardless of their behavioral response. Ketamine was infused for 60 min.

Results

Ketamine-induced loss of consciousness was identified during a gradual evolution of the high beta-gamma oscillations. The slow oscillations appeared to develop at a later stage of ketamine anesthesia. Return of consciousness and return of preanesthetic performance level (performance return) were observed during a gradual drift of the gamma oscillations toward the beta frequency. Ketamine-induced loss of consciousness, return of consciousness, and performance return are all identified during a gradual change of the dynamics, distinctive from the abrupt neural changes at propofol-induced loss of consciousness and return of consciousness. Multisensory responses indicate that puff evoked potentials and single-unit firing responses to puff were both preserved during ketamine anesthesia, but sound responses were selectively diminished. Units with suppressed responses and those with bimodal responses appeared to be inhibited under ketamine and delayed in recovery.

Conclusions

Ketamine generates unique intracortical dynamics during its altered states of consciousness, suggesting fundamentally different neuronal processes from propofol. The gradually shifting dynamics suggest a continuously conscious or dreaming state while unresponsive under ketamine until its deeper stage with the slow-delta oscillations. Somatosensory processing is preserved during ketamine anesthesia, but multisensory processing appears to be diminished under ketamine and through recovery.

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Myocardial Function during Low versus Intermediate Tidal Volume Ventilation in Patients without Acute Respiratory Distress Syndrome
Authors: Cherpanath Thomas G. V. , Simonis Fabienne D. , Bouma Berto J. , de Bruin-Bon Rianne H. , Determann Rogier M. , Juffermans Nicole P. , Gama de Abreu Marcelo , Pelosi Paolo , Serpa Neto Ary , Groeneveld Johan A. B. , Schultz Marcus J. , Lagrand Wim K.
Published: February 2020

Background

Mechanical ventilation with low tidal volumes has the potential to mitigate ventilation-induced lung injury, yet the clinical effect of tidal volume size on myocardial function has not been clarified. This cross-sectional study investigated whether low tidal volume ventilation has beneficial effects on myocardial systolic and diastolic function compared to intermediate tidal volume ventilation.

Methods

Forty-two mechanically ventilated patients without acute respiratory distress syndrome (ARDS) underwent transthoracic echocardiography after more than 24 h of mechanical ventilation according to the Protective Ventilation in Patients without ARDS (PReVENT) trial comparing a low versus intermediate tidal volume strategy. The primary outcome was left ventricular and right ventricular myocardial performance index as measure for combined systolic and diastolic function, with lower values indicating better myocardial function and a right ventricular myocardial performance index greater than 0.54 regarded as the abnormality threshold. Secondary outcomes included specific systolic and diastolic parameters.

Results

One patient was excluded due to insufficient acoustic windows, leaving 21 patients receiving low tidal volumes with a tidal volume size (mean ± SD) of 6.5 ± 1.8 ml/kg predicted body weight, while 20 patients were subjected to intermediate tidal volumes receiving a tidal volume size of 9.5 ± 1.6 ml/kg predicted body weight (mean difference, −3.0 ml/kg; 95% CI, −4.1 to −2.0; P < 0.001). Right ventricular dysfunction was reduced in the low tidal volume group compared to the intermediate tidal volume group (myocardial performance index, 0.41 ± 0.13 vs. 0.64 ± 0.15; mean difference, −0.23; 95% CI, −0.32 to −0.14; P < 0.001) as was left ventricular dysfunction (myocardial performance index, 0.50 ± 0.17 vs. 0.63 ± 0.19; mean difference, −0.13; 95% CI, −0.24 to −0.01; P = 0.030). Similarly, most systolic parameters were superior in the low tidal volume group compared to the intermediate tidal volume group, yet diastolic parameters did not differ between both groups.

Conclusions

In patients without ARDS, intermediate tidal volume ventilation decreased left ventricular and right ventricular systolic function compared to low tidal volume ventilation, although without an effect on diastolic function.

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Importance of Endotoxin Clearance in Endotoxemic Septic Shock: An Analysis From the Evaluating Use of PolymyxinB Hemoperfusion in a Randomized Controlled Trial of Adults Treated for Endotoxemic Septic Shock (EUPHRATES) Trial
Authors: Rachoin Jean-Sebastien , Foster Debra , Giese River , Weisberg Lawrence S. , Klein David J.
Published: February 2020

Objectives:

To investigate the relationship between survival and treatment-related reduction in endotoxin activity for patients in the Evaluating Use of PolymyxinB Hemoperfusion in a Randomized controlled trial of Adults Treated for Endotoxemia and Septic shock trial with baseline endotoxin activity assay greater than or equal to 0.60 to less than 0.90 units.

Design:

Post hoc analysis of a multicenter randomized controlled clinical trial.

Setting:

Fifty-five tertiary hospitals in North America.

Patients:

Patients with septic shock and endotoxin activity assay level greater than or equal to 0.60 to less than 0.90 and multiple organ dysfunction syndrome greater than 9.

Interventions:

Two polymyxin B hemoperfusion treatments or Sham.

Measurements and Main Results:

One-hundred ninety-four patients were included (88 polymyxin B and 106 Sham). We evaluated the impact of changes in endotoxin activity assay based on comparison to the median reduction from baseline to day 3 and a second method where a target post-treatment endotoxin activity assay level (day 3) was established. The population median reduction in endotoxin activity assay level was 10.4%. In patients with a greater than median reduction, there was trend toward lower mortality with polymyxin B (17.1% vs 33.3%; p = 0.07) and a significant increase in mechanical ventilation-free days (20 vs 13.5; p = 0.04). The pressure adjusted heart rate showed a significant improvement in the polymyxin B group (p = 0.02). For patients who achieved an endotoxin activity assay of less than 0.65 at day 3, the polymyxin B treated group had a trend toward a mortality reduction compared to Sham (16% vs 33%;p = 0.06) and a significant increase in ventilation-free day (20 vs 16; p = 0.05). Kaplan-Meier analysis showed a 17% reduction in mortality with polymyxin B (p = 0.04).

Conclusions:

These findings suggest that reducing endotoxin activity assay levels with polymyxin B as measured by comparison to a median reduction or when a treatment target is established, may result in improvements in mortality and organ function outcomes. This article is the first to report endotoxin activity assay measurements in response to polymyxin B use versus Sham in patients with septic shock and elevated endotoxin activity assay. These findings are considered to be hypothesis generating and will need to be prospectively validated.
Richness of sputum microbiome in acute exacerbations of eosinophilic chronic obstructive pulmonary disease
Authors: Qi Yu-Jing , Sun Xue-Jiao , Wang Zhe , Bin Yan-Fei , Li Ying-Hua , Zhong Xiao-Ning , Bai Jing , Deng Jing-Min , He Zhi-Yi
Published: February 2020

Background:

The eosinophilic chronic obstructive pulmonary disease (COPD) is known to be more sensitive to corticosteroid. The sputum microbiome has been shown to affect COPD prognosis, but its role in acute exacerbations of eosinophilic COPD is unclear. This study aimed to investigate the dynamic changes of the airway microbiome in patients with acute exacerbations of eosinophilic COPD.

Methods:

Fifty-seven patients with acute exacerbations of COPD from the First Affiliated Hospital of Guangxi Medical University between June 2017 and June 2018 were divided into two groups. Patients with eosinophils ≥300 cells/μL in the peripheral venous blood were assigned to the eosinophilic group (Eos) and the rest to the non-eosinophilic group (Noneos). All patients received similar treatment including inhaled budesonide according to the guidelines. The induced sputum microbiome was analyzed on the 1st and 7th day of treatment using the 16S ribosomal RNA (rRNA) method. The levels of interleukin (IL)-6 and IL-8 were measured in the plasma and the sensitivity to corticosteroids was determined in isolated peripheral blood mononuclear cells. Quantitative data were compared between the two groups using the independent samples t test or Mann-Whitney U test. Categorical data were evaluated using Chi-squared test or Fisher's exact test.

Results:

Twenty-six patients were classified into Eos group and 31 patients were classified into Noneos group. Prior to treatment, the alpha diversity (Shannon index) (2.65 ± 0.63 vs. 2.56 ± 0.54, t = 0.328, P 
= 0.747) and the structure of the sputum microbiome were similar in the Eos group and the Noneos group. After 7 days of treatment, alpha diversity increased in both groups, while the microbiome richness (Ace index) was significantly lower in the Eos group (561.87 ± 109.13 vs. 767.88 ± 148.48, t = −3.535, P 
= 0.002). At the same time, IL-6 (12.09 ± 2.85 pg/mL vs. 15.54 ± 2.45 pg/mL, t = −4.913, P < 0.001) and IL-8 (63.64 ± 21.69 pg/mL vs. 78.97 ± 17.13 pg/mL, t = −2.981, P = 0.004) decreased more significantly in the Eos group, and the percentages of inhibition of IL-8 at dexamethasone concentrations 10−8 to 10−6 mol/L were significantly higher in the Eos group than those in the Noneos group (all P < 0.05).

Conclusions:

The induced sputum microbiome richness decreased more significantly following treatment in the Eos patients compared to the Noneos patients. The lower plasma inflammatory factor levels and the higher percentage of inhibition of IL-8 might be due to higher corticosteroid sensitivity in Eos patients.
Hypertensive emergencies and urgencies in emergency departments: a systematic review and meta-analysis
Authors: Astarita Anna , Covella Michele , Vallelonga Fabrizio , Cesareo Marco , Totaro Silvia , Ventre Luca , Aprà Franco , Veglio Franco , Milan Alberto
Published: February 2020

Objectives:

The prevalence of hypertensive emergencies and urgencies and of acute hypertension-mediated organ damage (aHMOD) in emergency departments is unknown. Moreover, the predictive value of symptoms, blood pressure (BP) levels and cardiovascular risk factors to suspect the presence of aHMOD is still unclear. The aim of this study was to investigate the prevalence of hypertensive emergencies and hypertensive urgencies in emergency departments and of the relative frequency of subtypes of aHMOD, as well as to assess the clinical variables associated with aHMOD.

Methods:

We conducted a systematic literature search on PubMed, OVID, and Web of Science from their inception to 22 August 2019. Two independent investigators extracted study-level data for a random-effects meta-analysis.

Results:

Eight studies were analysed, including 1970 hypertensive emergencies and 4983 hypertensive urgencies. The prevalence of hypertensive emergencies and hypertensive urgencies was 0.3 and 0.9%, respectively [odds ratio for hypertensive urgencies vs. hypertensive emergencies 2.5 (1.4–4.3)]. Pulmonary oedema/heart failure was the most frequent subtype of aHMOD (32%), followed by ischemic stroke (29%), acute coronary syndrome (18%), haemorrhagic stroke (11%), acute aortic syndrome (2%) and hypertensive encephalopathy (2%). No clinically meaningful difference was found for BP levels at presentations. Hypertensive urgency patients were younger than hypertensive emergency patients by 5.4 years and more often complained of nonspecific symptoms and/or headache, whereas specific symptoms were more frequent among hypertensive emergency patients.

Conclusion:

Hypertensive emergencies and hypertensive urgencies are a frequent cause of access to emergency departments, with hypertensive urgencies being significantly more common. BP levels alone do not reliably predict the presence of aHMOD, which should be suspected according to the presenting signs and symptoms.