bluuebunny/crossref_metadata_2025 huggingface dataset:
The galaxy–halo size relation of low-mass galaxies in FIRE
Authors: Rohr Eric , Feldmann Robert , Bullock James S , Çatmabacak Onur , Boylan-Kolchin Michael , Faucher-Giguère Claude-André , Kereš Dušan , Liang Lichen , Moreno Jorge , Wetzel Andrew
Published: December 2021

Galaxy sizes correlate closely with the sizes of their parent dark matter haloes, suggesting a link between halo formation and galaxy growth. However, the precise nature of this relation and its scatter remains to be understood fully, especially for low-mass galaxies. We analyse the galaxy–halo size relation (GHSR) for low-mass ($M_\star \sim 10^{7-9}\, {\rm M}_\odot$) central galaxies over the past 12.5 billion years with the help of cosmological volume simulations (FIREbox) from the Feedback in Realistic Environments (FIRE) project. We find a nearly linear relationship between the half-stellar mass galaxy size R1/2 and the parent dark matter halo virial radius Rvir. This relation evolves only weakly since redshift z = 5: $R_{1/2}\, [{\rm kpc}] = (0.053\pm 0.002)(R_{\rm vir}/35\, {\rm kpc})^{0.934\pm 0.054}$, with a nearly constant scatter $\langle \sigma \rangle = 0.084\, [{\rm dex}]$. While this ratio is similar to what is expected from models where galaxy disc sizes are set by halo angular momentum, the low-mass galaxies in our sample are not angular momentum supported, with stellar rotational to circular velocity ratios vrot/vcirc ∼ 0.15. Introducing redshift as another parameter to the GHSR does not decrease the scatter. Furthermore, this scatter does not correlate with any of the halo properties we investigate – including spin and concentration – suggesting that baryonic processes and feedback physics are instead critical in setting the scatter in the GHSR. Given the relatively small scatter and the weak dependence of the GHSR on redshift and halo properties for these low-mass central galaxies, we propose using galaxy sizes as an independent method from stellar masses to infer halo masses.
II. The effect of axisymmetric and spatially varying equilibria and flow on MHD wave modes: cylindrical geometry
Authors: Skirvin S J , Fedun V , Silva Suzana S A , Verth G
Published: December 2021

Magnetohydrodynamic (MHD) waves are routinely observed in the solar atmosphere. These waves are important in the context of solar physics as it is widely believed they can contribute to the energy budget of the solar atmosphere and are a prime candidate to contribute towards coronal heating. Realistic models of these waves are required representing observed configurations such that plasma properties can be determined more accurately, since they cannot be measured directly. This work utilizes a previously developed numerical technique to find permittable eigenvalues under different non-uniform equilibrium conditions in a Cartesian magnetic slab geometry. Here, we investigate the properties of magnetoacoustic waves under non-uniform equilibria in a cylindrical geometry. Previously obtained analytical results are retrieved to emphasize the power and applicability of this numerical technique. Further case studies investigate the effect that a radially non-uniform plasma density and non-uniform plasma flow, modelled as a series of Gaussian profiles, have on the properties of different MHD waves. For all cases the dispersion diagrams are obtained and spatial eigenfunctions calculated which display the effects of the equilibrium inhomogeneity. It is shown that as the equilibrium non-uniformity is increased, the radial spatial eigenfunctions are affected and extra nodes introduced, similar to the previous investigation of a magnetic slab. Furthermore, azimuthal perturbations are increased with increasing inhomogeneity introducing vortical motions inside the waveguide. Finally, 2D and 3D representations of the velocity fields are shown which may be useful for observers for wave mode identification under realistic magnetic waveguides with ever increasing instrument resolution.
Scaling pair count to next galaxy surveys
Authors: Plaszczynski S , Campagne J E , Peloton J , Arnault C
Published: December 2021

Counting pairs of galaxies or stars according to their distance is at the core of real-space correlation analyses performed in astrophysics and cosmology. Upcoming galaxy surveys (LSST, Euclid) will measure properties of billions of galaxies challenging our ability to perform such counting in a minute-scale time relevant for the usage of simulations. The problem is only limited by efficient access to the data, hence belongs to the big data category. We use the popular Apache Spark framework to address it and design an efficient high-throughput algorithm to deal with hundreds of millions to billions of input data. To optimize it, we revisit the question of non-hierarchical sphere pixelization based on cube symmetries and develop a new one dubbed the ‘Similar Radius Sphere Pixelization’ (SARSPix) with very close to square pixels. It provides the most adapted indexing over the sphere for all distance-related computations. Using LSST-like fast simulations, we compute autocorrelation functions on tomographic bins containing between a hundred million to one billion data points. In each case, we achieve the construction of a standard pair-distance histogram in about 2 min, using a simple algorithm that is shown to scale, over a moderate number of nodes (16–64). This illustrates the potential of this new techniques in the field of astronomy where data access is becoming the main bottleneck. They can be easily adapted to other use-cases as nearest-neighbours search, catalogue cross-match or cluster finding. The software is publicly available from https://github.com/astrolabsoftware/SparkCorr.
A simple time-dependent method for calculating spirals: applications to eccentric planets in protoplanetary discs
Authors: Zhu Zhaohuan , Zhang Raymond M
Published: December 2021

Spirals in protoplanetary discs have been used to locate the potential planet in discs. Since only the spiral shape from a circularly orbiting perturber is known, most previous works assume that the planet is in a circular orbit. We develop a simple semi-analytical method to calculate the shape of the spirals launched by an eccentric planet. We assume that the planet emits wavelets during its orbit, and the wave fronts of these propagating wavelets form the spirals. The resulting spiral shape from this simple method agrees with numerical simulations exceptionally well. The spirals excited by an eccentric planet can detach from the planet, bifurcate, or even cross each other, which are all reproduced by this simple method. The spiral’s bifurcation point corresponds to the wavelet that is emitted when the planet’s radial speed reaches the disc’s sound speed. Multiple spirals can be excited by an eccentric planet (more than five spirals when e ≳ 0.2). The pitch angle and pattern speed are different between different spirals and can vary significantly across one spiral. The spiral wakes launched by high-mass eccentric planets steepen to spiral shocks and the crossing of spiral shocks leads to distorted or broken spirals. With the same mass, a more eccentric planet launches weaker spirals and induces a shallower gap over a long period of time. The observed unusually large/small pitch angles of some spirals, the irregular multiple spirals, and the different pattern speeds between different spirals may suggest the existence of eccentric perturbers in protoplanetary discs.
Inside–out planet formation: VI. oligarchic coagulation of planetesimals from a pebble ring?
Authors: Cai Maxwell X , Tan Jonathan C , Portegies Zwart Simon
Published: December 2021

Inside–Out Planet Formation (IOPF) is a theory addressing the origin of Systems of Tightly-Packed Inner Planets (STIPs) via in situ formation and growth of the planets. It predicts that a pebble ring is established at the pressure maximum associated with the dead zone inner boundary (DZIB) with an inner disc magnetorotational instability (MRI)-active region. Using direct N-body simulations, we study the collisional evolution of planetesimals formed from such a pebble ring, in particular, examining whether a single dominant planet emerges. We consider a variety of models, including some in which the planetesimals are continuing to grow via pebble accretion. We find that the planetesimal ring undergoes oligarchic evolution, and typically turns into 2 or 3 surviving oligarchs on nearly coplanar and circular orbits, independent of the explored initial conditions or form of pebble accretion. The most massive oligarchs typically consist of about $70{{\ \rm per\ cent}}$ of the total mass, with the building-up process typically finishing within ∼105 yr. However, a relatively massive secondary planet always remains with $\sim 30\!-\!65{{\ \rm per\ cent}}$ of the mass of the primary. Such secondary planets have properties that are inconsistent with the observed properties of the innermost pairs of planets in STIPs. Thus, for IOPF to be a viable theory for STIP formation, it needs to be shown how oligarchic growth of a relatively massive secondary from the initial pebble ring can be avoided. We discuss some potential additional physical processes that should be included in the modelling and explored as next steps.
Echocardiographic features of acute-phase microscopic polyangiitis in Japanese patients: A single-centre retrospective study
Authors: Nawata Takashi , Kinoshita Natsu , Okuda Shinichi , Kubo Makoto , Wada Yasuaki , Kobayashi Shigeki , Tanaka Nobuaki , Yano Masafumi
Published: December 2021

Objectives

Microscopic polyangiitis (MPA) affects various organs. However, echocardiographic findings of MPA are unclear. We aimed to evaluate the echocardiographic features of acute-phase MPA in Japanese patients.

Methods

This single-centre retrospective study included 15 patients with MPA who underwent echocardiography within 2 weeks of commencing steroid therapy for induction or reinduction. The echocardiography parameters of thetients were compared with those of 30 age- and sex-matched controls.

Results

No significant differences in left ventricular (LV) diameter, LV ejection fraction, or e’ were observed between the two groups. However, the MPA group showed a significantly higher left atrial (LA) diameter and LA volume index, as well as higher early diastolic filling velocity, diastolic pulmonary venous flow velocity, and trans-tricuspid pressure gradient, and a shorter deceleration time (DCT). Serum C-reactive protein levels were positively correlated with E wave, E/A, and DCT. These results may indicate that increased LV stiffness, rather than impairment of LV relaxation, contributed to LV diastolic function, resulting in LA enlargement.

Conclusions

Patients with acute-phase MPA had LA dilatation associated with LV diastolic dysfunction. This finding indicates the importance of cardiac assessment in patients with MPA, especially in patients with a strong inflammatory reaction.
Ultrasound assessment of sarcopenia in patients with rheumatoid arthritis
Authors: Yoshida Takeshi , Kumon Yoshitaka , Takamatsu Naoko , Nozaki Taiki , Inoue Masataka , Nodera Hiroyuki , Albayda Jemima , Izumi Yuishin
Published: December 2021

Objectives

To evaluate the efficacy of ultrasound (US) as a diagnostic tool for sarcopenia in patients with rheumatoid arthritis (RA).

Methods

Female RA patients aged >50 years and matched controls were cross-sectionally assessed. Sarcopenia was diagnosed based on the 2019-updated Asian Working Group for Sarcopenia definition. The cross-sectional area (CSA) and echo intensity (EI) of the biceps brachii, rectus femoris, and EI of the vastus lateralis were examined bilaterally. Correction for subcutaneous fat and calculation of the recorrected EI (rcEI) were performed. We performed logistic regression using both muscle rcEI and CSA with receiver operating curve analysis to evaluate the discriminative performance per muscle group.

Results

Seventy-eight consecutive RA patients and 15 age-and sex-matched controls were assessed. Sarcopenia was diagnosed in 34 RA patients (43.6%). The rcEI of examined muscles were significantly higher, whereas CSA were significantly lower in sarcopenic RA patients than in non-sarcopenic patients and matched controls. The combined discriminative performance of rcEI and CSA was superior to those of rcEI or CSA alone.

Conclusions

This study suggests the use of US for the diagnosis of sarcopenia in RA patients. The diagnostic performance increases when both echogenicity and CSA are considered together rather than individually.
Mechanics of CRISPR-Cas12a and engineered variants on λ-DNA
Authors: Paul Bijoya , Chaubet Loïc , Verver Dideke Emma , Montoya Guillermo
Published: December 2021

Cas12a is an RNA-guided endonuclease that is emerging as a powerful genome-editing tool. Here, we selected a target site on bacteriophage λ-DNA and used optical tweezers combined with fluorescence to provide mechanistic insight into wild type Cas12a and three engineered variants, where the specific dsDNA and the unspecific ssDNA cleavage are dissociated (M1 and M2) and a third one which nicks the target DNA (M3). At low forces wtCas12a and the variants display two main off-target binding sites, while on stretched dsDNA at higher forces numerous binding events appear driven by the mechanical distortion of the DNA and partial matches to the crRNA. The multiple binding events onto dsDNA at high tension do not lead to cleavage, which is observed on the target site at low forces when the DNA is flexible. In addition, activity assays also show that the preferential off-target sites for this crRNA are not cleaved by wtCas12a, indicating that λ-DNA is only severed at the target site. Our single molecule data indicate that the Cas12a scaffold presents singular mechanical properties, which could be used to generate new endonucleases with biomedical and biotechnological applications.
Direct observation of nodeless superconductivity and phonon modes in electron-doped copper oxide Sr1−xNdxCuO2
Authors: Fan Jia-Qi , Yu Xue-Qing , Cheng Fang-Jun , Wang Heng , Wang Ruifeng , Ma Xiaobing , Hu Xiao-Peng , Zhang Ding , Ma Xu-Cun , Xue Qi-Kun , Song Can-Li
Published: December 2021

The microscopic understanding of high-temperature superconductivity in cuprates has been hindered by the apparent complexity of crystal structures in these materials. We used scanning tunneling microscopy and spectroscopy to study the electron-doped copper oxide compound Sr1−xNdxCuO2, which has only bare cations separating the CuO2 planes and thus the simplest infinite-layer structure of all cuprate superconductors. Tunneling conductance spectra of the major CuO2 planes in the superconducting state revealed direct evidence for a nodeless pairing gap, regardless of variation of its magnitude with the local doping of trivalent neodymium. Furthermore, three distinct bosonic modes are observed as multiple peak-dip-hump features outside the superconducting gaps and their respective energies depend little on the spatially varying gaps. As well as the bosonic modes, with energies identical to those of the external, bending and stretching phonons of copper oxides, our findings reveal the origin of the bosonic modes in lattice vibrations rather than spin excitations.
Multicenter, Prospective Validation of a Phenotypic Algorithm to Guide Carbapenemase Testing in Carbapenem-ResistantPseudomonas aeruginosaUsing the ERACE-PA Global Surveillance Program
Authors: Gill Christian M , Aktaþ Elif , Alfouzan Wadha , Bourassa Lori , Brink Adrian , Burnham Carey-Ann D , Canton Rafael , Carmeli Yehuda , Falcone Marco , Kiffer Carlos , Marchese Anna , Martinez Octavio , Pournaras Spyros , Satlin Michael J , Seifert Harald , Thabit Abrar K , Thomson Kenneth S , Villegas Maria Virginia , Nicolau David P
Published: December 2021

Background

Carbapenemase-producing, carbapenem-resistant Pseudomonas aeruginosa (CP-CRPA) is a global challenge. However, detection efforts can be laborious because numerous mechanisms produce carbapenem resistance. A minimum inhibitory concentration–based algorithm (imipenem- or meropenem-resistant plus ceftazidime-nonsusceptible plus cefepime-nonsusceptible) was proposed to identify the isolates most likely to harbor a carbapenemase; however, prospective validation in geographies displaying genotypic diversity and varied carbapenemase prevalence is warranted.

Methods

CRPA isolates were collected during the Enhancing Rational Antimicrobials for P. aeruginosa (ERACE-PA) global surveillance program from 17 sites in 12 countries. Isolates underwent susceptibility testing following local standards to ceftazidime, cefepime, and ceftolozane/tazobactam. Isolates underwent initial phenotypic carbapenemase screening followed by molecular testing if positive. The primary algorithm criteria were applied, and results were compared with phenotypic carbapenemase results to assess the performance of the algorithm. A secondary criterion, the algorithm criterion or imipenem- or meropenem-resistant plus ceftolozane/tazobactam-nonsusceptible, was assessed.

Results

A total of 807 CRPA were assessed, and 464 isolates met the algorithm criteria described above. Overall, testing was reduced by 43% compared with testing all CRPA. Carbapenemase-positive isolates missed by the algorithm were largely driven by Guiana extended spectrum (GES). Addition of the criterion of imipenem- or meropenem-resistant plus ceftolozane/tazobactam-nonsusceptible decreased the number of CP-CRPA missed by the algorithm (21 vs 40 isolates, respectively), reducing number of isolates tested by 39%.

Conclusions

Application of the initial algorithm (imipenem- or meropenem-resistant plus ceftazidime-nonsusceptible plus cefepime-nonsusceptible) performed well in a global cohort, with 33% phenotypically carbapenemase-positive isolates. The addition of imipenem- or meropenem-resistant plus ceftolozane/tazobactam-nonsusceptible reduced the number of phenotypically carbapenemase-positive isolates missed and may be useful in areas with a prominence of GES.
Investigation of the upper atmosphere in ultra-hot Jupiter WASP-76 b with high-resolution spectroscopy
Authors: Kawauchi Kiyoe , Narita Norio , Sato Bun’ei , Kawashima Yui
Published: December 2021

Alkali metal lines are one of the most important key opacity sources for understanding exoplanetary atmospheres because the Na i resonance doublets are thought to be the cause of low albedo, as the alkali metal’s wide line wings absorb almost all of the incoming stellar irradiation. High-resolution transmission spectroscopy of Na absorption lines can be used to investigate the temperature of the thermosphere of hot Jupiters, which is increased by stellar X-ray and extreme-ultraviolet irradiation. We applied high-resolution transmission spectroscopy to the ultra-hot Jupiter WASP-76 b with the High Dispersion Spectrograph (HDS) on the Subaru 8.2 m telescope. We report the detection of strong Na D excess absorption with line contrasts of $0.42 \pm 0.03\%$ (D1 at 5895.92 Å) and $0.38\pm 0.04\%$ (D2 at 5889.95 Å), full width at half maximum values of 1.63 ± 0.13 Å (D1) and 1.87 ± 0.22 Å (D2), and equivalent widths of (7.29 ± 1.43) × 10−3 Å (D1) and (7.56 ± 2.38) × 10−3 Å (D2). These results show that the Na D absorption lines are shallower and broader than those in previous work, whereas the absorption signals over the same passband are consistent with those in previous work. We derive the best-fitting isothermal temperature of 3700 K (without rotation) and 4200 K (with rotation). These results suggest the possibility of the existence of a thermosphere because the derived atmospheric temperature is higher than the equilibrium temperature (∼2160 K).
The radio dichotomy of active galactic nuclei
Authors: Xiao Hubing , Zhu Jingtian , Fu Liping , Zhang Shaohua , Fan Junhui
Published: December 2021

The question of radio dichotomy in active galactic nuclei (AGNs) is still in debate, even though it has been discussed for more than 40 years. In order to solve this old riddle, we collect a sample of AGNs with optical B band and radio 6 cm wavelength data to analyze the radio loudness log R. Our results indicate a separation of log R = 〈1.37 ± 0.02〉 between radio-loud (RL) AGNs and radio-quiet (RQ) AGNs, suggesting the existence of an RL/RQ dichotomy. For the first time, we suggest combining radio luminosity and radio loudness as a double criterion to divide AGNs into RLs and RQs to avoid misclassification problems that may happen in the single-criterion scenario; we propose the double-criterion dividing line log L6 cm = −2.7log R + 44.3 by using a machine-learning method. In addition, the key point of the RL/RQ dichotomy is the origin of radio emission for the two classes, and we suggest the radio emission from RLs and RQs share the same origin, e.g., jets and mini-jets (aborted-jet or outflow), through a correlation study between radio 6 cm luminosity and optical B-band luminosity.
The structural connectome in ADHD
Authors: Bu Xuan , Cao Miao , Huang Xiaoqi , He Yong
Published: December 2021

Attention-deficit/hyperactivity disorder (ADHD) has been conceptualized as a brain dysconnectivity disorder. In the past decade, noninvasive diffusion magnetic resonance imaging (dMRI) studies have demonstrated that individuals with ADHD have alterations in the white matter structural connectome, and that these alterations are associated with core symptoms and cognitive deficits in patients. This review aims to summarize recent dMRI-based structural connectome studies in ADHD from voxel-, tractography-, and network-based perspectives. Voxel- and tractography-based studies have demonstrated disrupted microstructural properties predominantly located in the frontostriatal tracts, the corpus callosum, the corticospinal tracts, and the cingulum bundle in patients with ADHD. Network-based studies have suggested abnormal global and local efficiency as well as nodal properties in the prefrontal and parietal regions in the ADHD structural connectomes. The altered structural connectomes in those with ADHD provide significant signatures for prediction of symptoms and diagnostic classification. These studies suggest that abnormalities in the structural connectome may be one of the neural underpinnings of ADHD psychopathology and show potential for establishing imaging biomarkers in clinical evaluation. However, given that there are inconsistent findings across studies due to sample heterogeneity and analysis method variations, these ADHD-related white matter alterations are still far from informing clinical practice. Future studies with larger and more homogeneous samples are needed to validate the consistency of current results; advanced dMRI techniques can help to generate much more precise estimation of white matter pathways and assure specific fiber configurations; and finally, dimensional analysis frameworks can deepen our understanding of the neurobiology underlying ADHD.
Evaluating the physicochemical effects of conjugating peptides into thermogelling hydrogels for regenerative biomaterials applications
Authors: Pearce Hannah A , Jiang Emily Y , Swain Joseph W R , Navara Adam M , Guo Jason L , Kim Yu Seon , Woehr Andrew , Hartgerink Jeffrey D , Mikos Antonios G
Published: December 2021

Thermogelling hydrogels, such as poly(N-isopropylacrylamide) [P(NiPAAm)], provide tunable constructs leveraged in many regenerative biomaterial applications. Recently, our lab developed the crosslinker poly(glycolic acid)-poly(ethylene glycol)-poly(glycolic acid)-di(but-2-yne-1,4-dithiol), which crosslinks P(NiPAAm-co-glycidyl methacrylate) via thiol-epoxy reaction and can be functionalized with azide-terminated peptides via alkyne-azide click chemistry. This study’s aim was to evaluate the impact of peptides on the physicochemical properties of the hydrogels. The physicochemical properties of the hydrogels including the lower critical solution temperature, crosslinking times, swelling, degradation, peptide release and cytocompatibility were evaluated. The gels bearing peptides increased equilibrium swelling indicating hydrophilicity of the hydrogel components. Comparable sol fractions were found for all groups, indicating that inclusion of peptides does not impact crosslinking. Moreover, the inclusion of a matrix metalloproteinase-sensitive peptide allowed elucidation of whether release of peptides from the network was driven by hydrolysis or enzymatic cleavage. The hydrophilicity of the network determined by the swelling behavior was demonstrated to be the most important factor in dictating hydrogel behavior over time. This study demonstrates the importance of characterizing the impact of additives on the physicochemical properties of hydrogels. These characteristics are key in determining design considerations for future in vitro and in vivo studies for tissue regeneration.
Two Factors, Five Factors, or Both? External Validation Studies of Negative Symptom Dimensions in Schizophrenia
Authors: Ahmed Anthony O , Kirkpatrick Brian , Granholm Eric , Rowland Laura M , Barker Peter B , Gold James M , Buchanan Robert W , Outram Tacina , Bernardo Miguel , Paz García-Portilla María , Mane Anna , Fernandez-Egea Emilio , Strauss Gregory P
Published: December 2021

Objectives

Negative symptom studies frequently use single composite scores as indicators of symptom severity and as primary endpoints in clinical trials. Factor analytic and external validation studies do not support this practice but rather suggest a multidimensional construct. The current study used structural equation modeling (SEM) to compare competing dimensional models of negative symptoms to determine the number of latent dimensions that best capture variance in biological, psychological, and clinical variables known to have associations with negative symptoms.

Methods

Three independent studies (total n = 632) compared unidimensional, two-factor, five-factor, and hierarchical conceptualizations of negative symptoms in relation to cognition, psychopathology, and community functioning (Study 1); trait emotional experience and defeatist performance beliefs (Study 2); and glutamate and gamma-aminobutyric acid levels in the anterior cingulate cortex quantified using proton magnetic resonance spectroscopy (Study 3).

Results

SEM favored the five-factor and hierarchical models over the unidimensional and two-factor models regardless of the negative symptom measure or external validator. The five dimensions—anhedonia, asociality, avolition, blunted affect, and alogia—proved vital either as stand-alone domains or as first-order domains influenced by second-order dimensions—motivation and pleasure and emotional expression. The two broader dimensions sometimes masked important associations unique to the five narrower domains. Avolition, anhedonia, and blunted affect showed the most domain-specific associations with external variables across study samples.

Conclusions

Five domains and a hierarchical model reflect the optimal conceptualization of negative symptoms in relation to external variables. Clinical trials should consider using the two dimensions as primary endpoints and the five domains as secondary endpoints.
Physical Activity and Sleep in 11-Year Old Children With a Familial High Risk of Schizophrenia or Bipolar Disorder. The Danish High Risk and Resilience Study—VIA 11
Authors: Søndergaard Anne , Wilms Martin , Gregersen Maja , Brandt Julie Marie , Krantz Mette Falkenberg , Rohd Sinnika Birkehøj , Johnsen Line Korsgaard , Hemager Nicoline , Hjorthøj Carsten , Ohland Jessica , Andreassen Anna Krogh , Knudsen Christina Bruun , Veddum Lotte , Greve Aja , Bliksted Vibeke , Mors Ole , Krustrup Peter , Thorsteinsson Troels , Schmidt-Andersen Peter , Kjærgaard Morten , Lykkegaard Kasper , Thorup Anne Amalie Elgaard , Nordentoft Merete
Published: December 2021

Objective

People with schizophrenia and bipolar disorder are at increased risk of having comorbid somatic illness. This is partly due to lack of physical activity, which may originate from childhood. Sleep disturbances are associated with schizophrenia and bipolar disorder. We aimed to assess physical activity and sleep in children at familial high risk of schizophrenia or bipolar disorder and population-based controls

Methods

This study is part of The Danish High Risk and Resilience Study—VIA 11. Children aged 11 born to parents with schizophrenia (FHR-SZ) (N = 133), bipolar disorder (FHR-BP) (N = 84), or controls (C) (N = 150) were assessed by accelerometry for an average of 6.9 days.

Results

High-intensity physical activity was significantly lower in children at FHR-SZ and FHR-BP compared to controls, (mean hours per day for FHR-SZ: 0.29, SD 0.19, for FHR-BP: 0.27, SD 0.24, and for controls 0.38, SD 0.22, P = <.001). Sleep did not differ between the groups.

Conclusion

Children at FHR-SZ or FHR-BP had less physical activity compared to controls. Our study highlights a research area that reveals a hitherto unexplored disadvantage of being born to parents with schizophrenia or bipolar disorder. Further research is needed to enhance better understanding of causal pathways and consequences of reduced physical activity in children with FHR-SZ and FHR-BP.
PARP Inhibitors in Pancreatic Cancer
Authors: Brown Timothy J. , Reiss Kim A.
Published: December 2021

Despite representing only 5% of all annual cancer diagnoses in the United States, pancreatic cancer is projected to become the second leading cause of cancer-related death within the next 10 years. Progress in the treatment of advanced pancreatic cancer has been slow. Systemic therapies rely on combination cytotoxic agents, with limited options at progression. Recently, poly(ADP-ribose) polymerase inhibitors have demonstrated clinical activity in patients with advanced pancreatic cancer and pathogenic variants in BRCA1, BRCA2, and PALB2. In this review, we discuss the development of poly(ADP-ribose) polymerase inhibitors in pancreatic cancer, relevant clinical trials, and future directions.
Poly(ADP-Ribose) Polymerase Inhibitor Inhibition in Ovarian Cancer
Authors: Moore Kathleen N. , Pothuri Bhavana
Published: December 2021

The emergence of clinical trial data for poly(ADP-ribose) polymerase inhibitors (PARPi), in BRCA-associated ovarian cancer (epithelial ovarian cancer [EOC]) in 2009 (Lancet 2010;376:245–251) unleashed a rapid series of additional asset development and clinical trial activation across all lines of EOC treatment, ultimately leading to 8 new approvals of 3 different PARPi in EOC since 2014. Monotherapy iPARPi were approved as frontline maintenance treatment for all patients with EOC who respond to platinum-based chemotherapy irrespective of biomarker (niraparib) and for BRCA-associated cancers (olaparib) (https://www.azpicentral.com/lynparza_tb/lynparza_tb.pdf#page=1; https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/208447s015s017lbledt.pdf). Combination of olaparib and bevacizumab was approved as maintenance for patients in response to platinum-based and bevacizumab containing frontline therapy whose tumor is characterized as homologous recombination deficient and as approved test by the Food and Drug Administration, inclusive of BRCA-associated cancers (N Engl J Med 2019;381:2416–2428). Niraparib, olaparib, and rucaparib were also approved as maintenance treatment following response to platinum-based therapy in the recurrent setting irrespective of biomarker (https://www.azpicentral.com/lynparza_tb/lynparza_tb.pdf#page=1; https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/208447s015s017lbledt.pdf; https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/209115s003lbl.pdf). All 3 PARPi were also approved as treatment in lieu of chemotherapy for patients with BRCA-associated cancers in third line and beyond (https://www.azpicentral.com/lynparza_tb/lynparza_tb.pdf#page=1;https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/209115s003lbl.pdf) and platinum-sensitive homologous recombination deficient in the fourth line and beyond (https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/208447s015s017lbledt.pdf), as well as the National Comprehensive Cancer Network listed in combination with bevacizumab for treatment of patients with platinum-sensitive recurrent disease (https://www.nccn.org/professionals/physician_gls/pdf/ovarian.pdf). Ongoing clinical trials in all lines of treatment are evaluating combinations of therapies to improve efficacy among biomarker negative tumors as well as overcome acquired PARPi resistance due to prior use.
Poly(ADP-Ribose) Polymerase Inhibitor Combination Therapy
Authors: Miller Rowan E.
Published: December 2021

The introduction of poly(ADP-ribose) polymerase (PARP) inhibitors has led to significant improvements in outcome for several cancer types, most notably high-grade serous ovarian cancer. However, in general, benefit is restricted to tumors characterized by either BRCA1/2 mutation or homologous recombination deficiency. Combination therapy offers the potential to overcome innate and acquired PARP inhibitor resistance by either working synergistically with PARP inhibitors or by targeting the homologous recombination repair pathway through an alternate strategy, to restore homologous recombination deficiency. Several biological agents have been studied in combination with PARP inhibitors, including inhibitors of vascular endothelial growth factor (vascular endothelial growth factor; bevacizumab, cediranib), AKT (capivasertib), PI3K inhibitors (buparlisib, alpelisib), epidermal growth factor receptor and BET inhibitors. In general, PARP inhibitor and biological agent combinations are well tolerated, and early data suggest that they are clinically effective in both BRCA1/2 mutant and wild-type cancers. In this review, we discuss multiple clinical trials that are underway examining the antitumor activity of the most promising combination strategies.
National Trends in Length of Stay for Microvascular Breast Reconstruction: An Evaluation of 10,465 Cases Using the American College of Surgeons National Surgical Quality Improvement Program Database
Authors: Holoyda Kathleen A. , Magno-Padron David A. , Carter Gentry C. , Agarwal Jay P. , Kwok Alvin C.
Published: December 2021

Background:

Decreasing length of stay benefits patients and hospital systems alike. This should be accomplished safely without negatively impacting patient outcomes. The authors hypothesize that in the United States, the average length of stay for patients undergoing microsurgical breast reconstruction has decreased since 2012 without a concurrent increase in complication and readmission rates.

Methods:

The authors identified female patients who underwent microvascular breast reconstruction (CPT 19364) from the 2012 to 2018 National Surgical Quality Improvement Program database. Trends in complication and readmission rates and length of stay were examined over 7 years. Multivariable logistic regression models and Mann-Kendall trend tests were used to evaluate associations between length of stay and complication and readmission rates.

Results:

A total of 10,465 cases were identified. The number of autologous microvascular breast reconstruction procedures performed increased annually between 2012 and 2018. Length of stay decreased significantly from 2012 to 2018 (from 4.47 days to 3.90 days) (p < 0.01). Minor and major complication rates remained constant, although major complications showed a decreasing trend (from 27 percent to 21 percent) (p = 0.07). Thirty-day readmission, surgical-site infection, and wound dehiscence rates remained consistent over the study period, whereas rates of blood transfusion or bleeding decreased (p = 0.02).

Conclusions:

Using a national sample from 2012 to 2018, the authors observed a significant decrease in length of stay for patients undergoing microvascular breast reconstruction without a concurrent increase in complication and readmission rates. Current efforts to reduce length of stay have been successful without increasing complication or readmission rates.

CLINICAL QUESTION/LEVEL OF EVIDENCE:

Risk, III.
“A-PePSI LIGhT” Assessment Score to Predict Pressure Sore Impaired Healing Late Recurrence, Immobility, Greater Surface, Inhibited Thrombocytes
Authors: Anker Alexandra M. , Ruewe Marc , Prantl Lukas , Geis Sebastian , Kehrer Andreas , Baringer Magnus , Schiltz Daniel , Zeman Florian , Vykoukal Jody , Klein Silvan M.
Published: December 2021

Background:

Complication rates of up to 46 percent are reported following pressure sore surgery. Pressure sore patients often exhibit ineffective postoperative wound healing despite tension-free flap coverage, necessitating surgical revision and prolonged hospitalization. Rather than pressure sore recurrence, such impaired healing reflects a failed progress through the physiologic stages of the normal wound-healing cascade. The principal objective of the study reported here was to elucidate potentially modifiable inherent variables that predict predisposition to impaired healing and to provide a tool for identifying cases at risk for complicated early postoperative recovery following pressure sore reconstruction.

Methods:

A retrospective chart review of late-stage (stage 3 or higher) sacral and ischial pressure sore patients who underwent flap reconstruction from 2014 to 2019 was performed. A multivariable logistic regression model was used to identify key patient and operative factors predictive of impaired healing. Furthermore, the Assessment Score to Predict Pressure Sore Impaired Healing (A-PePSI) was established based on the identified risk factors.

Results:

In a cohort of 121 patients, 36 percent exhibited impaired healing. Of these, 34 patients suffered from dehiscences, necessitating surgical revision. Statistically significant risk factors comprising late recurrence (OR, 3.8), immobility (OR, 12.4), greater surface (>5 cm diameter; OR, 7.3), and inhibited thrombocytes (aspirin monotherapy; OR, 5.7) were combined to formulate a prognostic scoring system (A-PePSI LIGhT).

Conclusions:

The A-PePSI LIGhT score serves as a prognostic instrument for assessing individual risk for impaired healing in pressure sore patients. Preoperative risk stratification supports rational decision-making regarding operative candidacy, allows evidence-based patient counseling, and supports the implementation of individualized treatment protocols. 

CLINICAL QUESTION/LEVEL OF EVIDENCE:

Risk, III.
Efficiency fosters cumulative culture across species
Authors: Gruber T. , Chimento M. , Aplin L. M. , Biro D.
Published: December 2021

Recent studies in several taxa have demonstrated that animal culture can evolve to become more efficient in various contexts ranging from tool use to route learning and migration. Under recent definitions, such increases in efficiency might satisfy the core criteria of cumulative cultural evolution (CCE). However, there is not yet a satisfying consensus on the precise definition of efficiency, CCE or the link between efficiency and more complex, extended forms of CCE considered uniquely human. To bring clarity to this wider discussion of CCE, we develop the concept of efficiency by (i) reviewing recent potential evidence for CCE in animals, and (ii) clarifying a useful definition of efficiency by synthesizing perspectives found within the literature, including animal studies and the wider iterated learning literature. Finally, (iii) we discuss what factors might impinge on the informational bottleneck of social transmission, and argue that this provides pressure for learnable behaviours across species. We conclude that framing CCE in terms of efficiency casts complexity in a new light, as learnable behaviours are a requirement for the evolution of complexity. Understanding how efficiency greases the ratchet of cumulative culture provides a better appreciation of how similar cultural evolution can be between taxonomically diverse species—a case for continuity across the animal kingdom.

This article is part of a discussion meeting issue ‘The emergence of collective knowledge and cumulative culture in animals, humans and machines’.
Social learning in swarm robotics
Authors: Bredeche Nicolas , Fontbonne Nicolas
Published: December 2021

In this paper, we present an implementation of social learning for swarm robotics. We consider social learning as a distributed online reinforcement learning method applied to a collective of robots where sensing, acting and coordination are performed on a local basis. While some issues are specific to artificial systems, such as the general objective of learning efficient (and ideally, optimal) behavioural strategies to fulfill a task defined by a supervisor, some other issues are shared with social learning in natural systems. We discuss some of these issues, paving the way towards cumulative cultural evolution in robot swarms, which could enable complex social organization necessary to achieve challenging robotic tasks.

This article is part of a discussion meeting issue ‘The emergence of collective knowledge and cumulative culture in animals, humans and machines’.
The experimental emergence of convention in a non-human primate
Authors: Formaux Anthony , Paleressompoulle Dany , Fagot Joël , Claidière Nicolas
Published: December 2021

Conventions form an essential part of human social and cultural behaviour and may also be important to other animal societies. Yet, despite the wealth of evidence that has accumulated for culture in non-human animals, we know surprisingly little about non-human conventions beyond a few rare examples. We follow the literature in behavioural ecology and evolution and define conventions as systematic behaviours that solve a coordination problem in which two or more individuals need to display complementary behaviour to obtain a mutually beneficial outcome. We start by discussing the literature on conventions in non-human primates from this perspective and conclude that all the ingredients for conventions to emerge are present and therefore that they ought to be more frequently observed. We then probe the emergence of conventions by using a unique novel experimental system in which pairs of Guinea baboons (Papio papio) can voluntarily participate together in touchscreen-based cognitive testing and we show that conventions readily emerge in our experimental set-up and that they share three fundamental properties of human conventions (arbitrariness, stability and efficiency). These results question the idea that observational learning, and imitation in particular, is necessary to establish conventions; they suggest that positive reinforcement is enough.

This article is part of a discussion meeting issue ‘The emergence of collective knowledge and cumulative culture in animals, humans and machines’.
Reconstructing social networks of Late Glacial and Holocene hunter–gatherers to understand cultural evolution
Authors: Romano Valéria , Lozano Sergi , Fernández-López de Pablo Javier
Published: December 2021

Culture is increasingly being framed as a driver of human phenotypes and behaviour. Yet very little is known about variations in the patterns of past social interactions between humans in cultural evolution. The archaeological record, combined with modern evolutionary and analytical approaches, provides a unique opportunity to investigate broad-scale patterns of cultural change. Prompted by evidence that a population's social connectivity influences cultural variability, in this article, we revisit traditional approaches used to infer cultural evolutionary processes from the archaeological data. We then propose that frameworks considering multi-scalar interactions (from individuals to populations) over time and space have the potential to advance knowledge in cultural evolutionary theory. We describe how social network analysis can be applied to analyse diachronic structural changes and test cultural transmission hypotheses using the archaeological record (here specifically from the Marine Isotope Stage 3ca57–29 ka onwards). We argue that the reconstruction of prehistoric networks offers a timely opportunity to test the interplay between social connectivity and culture and ultimately helps to disentangle evolutionary mechanisms in the archaeological record.

This article is part of a discussion meeting issue ‘The emergence of collective knowledge and cumulative culture in animals, humans and machines’.
Use of Sysmex UF-5000 flow cytometry in rapid diagnosis of urinary tract infection and the importance of validating carryover rates against bacterial count cut-off
Authors: Haugum Kjersti , Haugan Maria Schei , Skage Jannicke , Tetik Mariann , Jakovljev Aleksandra , Nilsen Hans-Johnny Schjelderup , Afset Jan Egil
Published: December 2021

Introduction. Urinary tract infections are common bacterial infections worldwide. Urine culture is the gold standard method to identify and quantify the presence or absence of bacteria in urine. Flow cytometry, which can differentiate and quantify multiple particles (including bacteria) in the urine, presents an alternative method for rapid screening to rule out bacteriuria.

Hypothesis. Adding flow cytometry to identify urine samples without bacteriuria could substantially reduce the number of urine samples that need to be cultured as well as the response time for negative results. However, the level of instrument rinsing between samples could affect sample-to-sample carryover rate, a concept given little attention in previous studies.

Aim. We aimed to evaluate urine flow cytometry as a rapid screening method to identify urine samples without significant bacterial growth, including analyses of cross-contamination and sample-to-sample carryover rate.

Methodology. We analysed 3919 urine samples by quantitative urine culture and flow cytometry screening (Sysmex UF-5000). Receiver operator characteristic (ROC) curve analyses were used to test method agreement to identify: (a) positive vs. negative culture and (b) mixed vs. pure culture. In addition, we performed carryover and cross-contamination studies.

Results. ROC curve analyses identified bacterial count (BACT ml−1) and leucocyte count (WBC µl−1) as possible predictors of bacterial growth in the total material and subpopulations, except pregnant women (n=451). This subgroup was excluded from further analyses, leaving a final 3468 urine samples. Area under the ROC curve was 0.94 (95 % CI 0.93–0.95) and 0.81 (95 % CI 0.79–0.82) for bacterial and leucocyte count, respectively. A bacterial count cut-off of 30 BACT ml−1 resulted in 95.2 % sensitivity and 91.2 % negative predictive value, resulting in approximately 30 % of urine samples that could be reported as negative without culture. Use of high-level rinse modes was necessary to ensure carryover rates <0.05 %.

Conclusion. Flow cytometry is a suitable and rapid method to rule out urine samples without significant bacterial growth. Rinses between samples should be adjusted, depending on the cut-off used, to prevent sample-to-sample carryover, whereas cross-contamination can be eliminated by the use of separate urine aliquots for flow cytometry analysis and urine culturing respectively.