bluuebunny/crossref_metadata_2025 huggingface dataset:
Virulence and antimicrobial resistance genes profiles ofspatype t605 methicillin-susceptibleStaphylococcus aureusisolated from subclinical bovine mastitis
Authors: Munive Nuñez Karen Vanessa , da Silva Abreu Anderson Clayton , Gonçalves Juliano Leonel , dos Santos Marcos Veiga , de Oliveira Rocha Liliana , Cirone Silva Nathália Cristina
Published: March 2023

Aims

Staphylococcus aureus is one of the most common pathogens associated with mastitis in dairy herds worldwide. This study evaluated the profile of virulence and antimicrobial resistance genes of spa type t605 methicillin-susceptible Staphylococcus aureus isolated from subclinical bovine mastitis in São Paulo, Brazil.

Methods and results

A total of 57 S. aureus strains were screened by conventional PCR (Polymerase Chain Reaction) for 49 virulence genes. The most prevalent virulence genes detected were icaD (94.7%), fib (93%), fnbA (82.5%), clfA (80.7%), bap (78.9%), clfB (73.7%), icaA (66.7%), see (64.9%), and sed (61.4%). The blaZ (94.7%), aac6’aph2’ (15.8%), and ant4 (12.3%) genes were the most common antimicrobial resistance genes; however, mecA and mecC genes were not found. All methicillin-susceptible S. aureus (MSSA) strains were characterized through spa and agr typing. The spa type t605 was found in all isolates. By agr typing, the most prevalent were type II (56.1%). Antimicrobial resistance was determined by the disk diffusion method, and 93% showed resistance to at least one antibiotic. Penicillin resistance was the most prevalent (87.7%), followed by tetracycline (12.3%), oxacillin (10.5%), and gentamicin (10.5%) resistance.

Conclusion

Our study confirmed the spa type t605 as endemic, carrying a wide variety of virulence factors and high-level penicillin resistance. The profile seems to be associated with the colonization of MSSA and its persistence in subclinical mastitis.
Monetary Policy, Corporate Finance, and Investment
Authors: Cloyne James , Ferreira Clodomiro , Froemel Maren , Surico Paolo
Published: March 2023

In response to a change in interest rates, younger firms not paying dividends adjust both their capital expenditure and borrowing significantly more than older firms paying dividends. The reason is that the debt of younger non-dividend payers is far more sensitive to fluctuations in collateral values, which are significantly affected by monetary policy. The results are robust to a wide range of possible confounding factors. Other channels, including movements in interest payments, product demand, profitability, and mark-ups, are also significant but seem unlikely to explain the heterogeneity in the response of capital expenditure. Our findings suggest that these types of financial frictions play an important role in the transmission of monetary policy.
Uddyotakara on Universals I: Against Resemblance Nominalism
Authors: Das Nilanjan
Published: March 2023

Universals are properties that are shared by multiple objects. In classical South Asia, Brahmanical thinkers from Vyākaraṇa, Nyāya, Vaiśeṣika, and Mīmāṃsā text traditions were realists about universals, while most Buddhists were nominalists. In this paper, my aim is to reconstruct the early Nyāya-Vaiśeṣika theory of universals, with special emphasis on the arguments of the Nyāya philosopher Uddyotakara (6th century CE) against a Buddhist strand of resemblance nominalism. I show that Uddyotakara's contribution to this debate is twofold. First, he is possibly the first Naiyāyika to adopt a sparse theory of universals, a theory according to which it is necessary to posit only those universals which explain how objects resemble each other in the most fundamental or irreducible respects. On the other hand, he offers a few arguments for realism, which are explicitly motivated by a causal constraint on intentionality.
Correspondence and canonicity theory of quasi-inequalities and Π2-statements in modal subordination algebras
Authors: Zhao Zhiguang
Published: March 2023

In the present paper, we study the correspondence and canonicity theory of modal subordination algebras and their dual Stone space with two relations, generalizing correspondence results for subordination algebras in [13–15, 25]. Due to the fact that the language of modal subordination algebras involves a binary subordination relation, we will find it convenient to use the so-called quasi-inequalities and $\varPi _{2}$-statements. We use an algorithm to transform (restricted) inductive quasi-inequalities and (restricted) inductive $\varPi _{2}$-statements to equivalent first-order correspondents on the dual Stone spaces with two relations with respect to arbitrary (resp. admissible) valuations.
Cytochromes P450 involved in bacterial RiPP biosyntheses
Authors: Kunakom Sylvia , Otani Hiroshi , Udwary Daniel W , Doering Drew T , Mouncey Nigel J
Published: March 2023

Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a large class of secondary metabolites that have garnered scientific attention due to their complex scaffolds with potential roles in medicine, agriculture, and chemical ecology. RiPPs derive from the cleavage of ribosomally synthesized proteins and additional modifications, catalyzed by various enzymes to alter the peptide backbone or side chains. Of these enzymes, cytochromes P450 (P450s) are a superfamily of heme-thiolate proteins involved in many metabolic pathways, including RiPP biosyntheses. In this review, we focus our discussion on P450 involved in RiPP pathways and the unique chemical transformations they mediate. Previous studies have revealed a wealth of P450s distributed across all domains of life. While the number of characterized P450s involved in RiPP biosyntheses is relatively small, they catalyze various enzymatic reactions such as C–C or C–N bond formation. Formation of some RiPPs is catalyzed by more than one P450, enabling structural diversity. With the continuous improvement of the bioinformatic tools for RiPP prediction and advancement in synthetic biology techniques, it is expected that further cytochrome P450-mediated RiPP biosynthetic pathways will be discovered.

The presence of genes encoding P450s in gene clusters for ribosomally synthesized and post-translationally modified peptides expand structural and functional diversity of these secondary metabolites, and here, we review the current state of this knowledge.
Residual malaria transmission and the role of Anopheles arabiensis and Anopheles melas in central Senegal
Authors: Sy Ousmane , Sarr Pape C , Assogba Benoit S , Nourdine Mouhamed A , Ndiaye Assane , Konaté Lassana , Faye Ousmane , Donnelly Martin J , Gaye Oumar , Weetman David , Niang Elhadji A
Published: March 2023

Understanding the behavior and ecology of local malaria vectors is essential for the effectiveness of the commonly used vector-targeted malaria control tools in areas of low malaria transmission. This study was conducted to determine species composition, biting behavior and infectivity of the major Anopheles vectors of Plasmodium falciparum in low transmission settings in central Senegal. Adult mosquitoes were collected using human landing catches during 2 consecutive nights and Pyrethrum Spray Catches in 30–40 randomly selected rooms, from July 2017 to December 2018 in 3 villages. Anopheline mosquitoes were morphologically identified using conventional keys; their reproductive status assessed by ovary dissections, and a sub-sample of Anopheles gambiae s.l. were identified to species level using polymerase chain reaction (PCR). Plasmodium sporozoite infections were detected using real-time quantitative PCR. During this study 3684 Anopheles were collected of which 97% were An. gambiae s.l., 0.6% were Anopheles funestus, and 2.4% were Anopheles pharoensis. Molecular identification of 1,877 An. gambiae s.l. revealed a predominance of Anopheles arabiensis (68.7%), followed by Anopheles melas (28.8%), and Anopheles coluzzii (2.1%). The overall human-biting rate of An. gambiae s.l. was highest in the inland site of Keur Martin with 4.92 bites per person per night, while it was similar in the deltaic site, Diofior (0.51) and the coastal site, Mbine Coly (0.67). Parity rates were similar in An. arabiensis (45%) and An. melas (42%). Sporozoite infections were detected in both An. arabiensis and An. melas with the respective infection rates of 1.39% (N = 8) and 0.41% (N = 1). Results suggest that low residual malaria in central Senegal is transmitted by An. arabiensis and An. melas. Consequently, both vectors will need to be targeted as part of malaria elimination efforts in this area of Senegal.
A new host record of Haemaphysalis semermis (Acari: Ixodidae) from the domestic cat (Felis catus) (Carnivora: Felidae) in Orang Asli village, Pahang National Park Malaysia
Authors: Kazim A R , Shezryna S , Azdayanti M , Houssaini J , Tappe D , Heo C C
Published: March 2023

We report the presence of a male Haemaphysalis semermis collected from the domestic cat, Felis catus in an aboriginal village located in Pahang, Malaysia. This paper constitutes a new host record of this tick species, and also the first documentation of the infestation of companion animals other than domestic dogs (Canis lupus) by H. semermis in Malaysia. Additionally, we have included an updated host index of the tick species in Southeast Asia.
Migratory biliary stent resulting in colonic perforation: a rare complication and review of literature
Authors: Wilson Zachary , Diab Jason , Putnis Soni
Published: March 2023

Biliary stent insertion during endoscopic retrograde cholangiopancreatography is used as a therapeutic intervention allowing flow of bile into the duodenum. In rare circumstances, distal gastrointestinal perforation can be attributed to a migrated biliary stent, with the most common site being the sigmoid colon. In these cases, surgical and/or endoscopic intervention may be required. We report a case of a 98-year-old male presenting with small bowel obstruction secondary to migrated plastic and metal biliary stents placed for acute biliary pancreatitis. Due to advanced age and high-risk multiple comorbidities, conservative management was undertaken. The patient was discharged after 5 days after ongoing pain and obstipation with palliative care services in place.
Diagnostic Performance of 10 Mathematical Formulae for Identifying Blood Donors with Thalassemia Trait
Authors: Noulsri Egarit , Lerdwana Surada , Palasuwan Duangdao , Palasuwan Attakorn
Published: March 2023

Objective

To compare the diagnostic performance of 10 mathematical formulae for identifying thalassemia trait in blood donors.

Methods

Compete blood counts were conducted on peripheral blood specimens using the UniCel DxH 800 hematology analyzer. Receiver operating characteristic curves were used to evaluate the diagnostic performance of each mathematical formula.

Results

In the 66 donors with thalassemia and 288 subjects with no thalassemia analyzed, donors with thalassemia trait had lower values for mean corpuscular volume and mean corpuscular hemoglobin than subjects without thalassemia donors (77 fL vs 86 fL [P < .001]; 25 pg vs 28 pg [P < .001]). The formula developed by Shine and Lal in 1977 showed the highest area under the curve value, namely, 0.9. At the cutoff value of <1812, this formula had maximum specificity of 82.35% and sensitivity of 89.58%.

Conclusions

Our data indicate that the Shine and Lal formula has remarkable diagnostic performance in identifying donors with underlying thalassemia trait.
Intersections of Forgiveness And ‘Queer Use’ In T.S. Eliot’s ‘Marina’
Authors: Kundu Tanya
Published: March 2023

Recent literary and theological accounts of forgiveness have appealed to the poetic as offering an ‘ambiguous’ space appropriate to the complex process of forgiving. In this article I will texture these accounts with a close reading of T.S. Eliot’s ‘Marina’, which is well-placed as an example of this style of poetics. Beyond ambiguity, however, ‘Marina’ communicates an account of forgiveness that can be read generatively alongside Sara Ahmed’s category of ‘queer use’. The poetics of ‘Marina’ will thereby provide a conceptual pattern for a movement towards healing, beyond painful histories, without erasing the past. This, in turn, will highlight the importance of Ahmed’s ‘queer use’ for contemporary theological accounts of forgiveness.
“Judea Declares War on Britain”: The Impact of American Jewish Anti-Nazi Protests on the Struggle for a Jewish State, 1945–1948
Authors: Norwood Stephen H
Published: March 2023

American Jews’ mass protests against Nazi antisemitism, begun soon after Hitler assumed power, provided a major impetus to, and model for, the post–World War II drive to establish a Jewish state. This postwar agitation had a considerable impact because, after the Holocaust, the Jewish population in the United States far exceeded that of any other country. The mass demonstrations of 1945–1948 were as large as those of the 1930s, even reaching 250,000, and in both periods, it was working- and lower–middle-class Jews who provided the intense commitment and huge numbers that proved critically important. Many speakers who had addressed the anti-Nazi rallies were featured at the postwar demonstrations for a Jewish state. Now promoting Zionist goals, American Jews turned to work stoppages, neighborhood rallies, and boycotts—resuming tactics deployed in the anti-Nazi campaign. Similarly, American Jews’ grassroots 1930s campaign to transport Jewish children from Nazi Germany to Palestine resurfaced after the Holocaust as a drive to generate mass support for the Haganah’s efforts to run Jewish displaced persons through the British blockade of Palestine. To great effect, American Zionists also frequently drew parallels between the Nazis’ actions and the British treatment of Jews in displaced persons camps, on refugee ships, and in the Yishuv.
Satmar and Neturei Karta: Jews Against Zionism
Authors: Keren-Kratz Menachem
Published: March 2023

Throughout history, many Jewish laymen and rabbis have objected to the collective return of the Jews to the Land of Israel, particularly if it was motivated by nationalistic rather than religious reasons. They did so for many reasons, the most persistent of which relied on a religious rationale. Anti-Zionist stands were voiced by both ends of the religious spectrum: the radical Reform on the one hand, and the ultra-Orthodox on the other. Following the establishment of the State of Israel, expressing anti-Zionist and anti-Israeli stands has become a routine practice among some Reform groups, as well as among several ultra-Orthodox communities among which Satmar is the most influential one. However, Neturei Karta’s position advocating Israel’s annihilation and their open support for Israel’s worst enemies has almost no parallel on the Reform side. During the twenty-first century, Neturei Karta’s anti-Zionist activities have become even more vehement. On top of the ordinary anti-Israel demonstrations side by side with supporters of Hamas, the PLO, or BDS, they have also participated in international conferences which promote Holocaust denial; visited Iran and met with its leaders who threaten to annihilate Israel; and rejected Israel’s raison d’être, claiming that Zionist leaders intentionally caused the Holocaust.
Updated radial velocities and new constraints on the nature of the unseen source in NGC1850 BH1
Authors: Saracino S , Shenar T , Kamann S , Bastian N , Gieles M , Usher C , Bodensteiner J , Kochoska A , Orosz J A , Sana H
Published: March 2023

A black hole candidate orbiting a luminous star in the Large Magellanic Cloud young cluster NGC 1850 (∼100 Myr) has recently been reported based on radial velocity and light-curve modelling. Subsequently, an alternative explanation has been suggested for the system: a bloated post-mass transfer secondary star (Minitial ∼ 4–5 M⊙ and Mcurrent ∼ 1–2 M⊙) with a more massive, yet luminous companion (the primary). Upon reanalysis of the MUSE spectra, we found that the radial velocity variations originally reported were underestimated (K2, revised = 176 ± 3 km s−1 versus K2, original = 140 ± 3 km s−1) because of the weighting scheme adopted in the full-spectrum fitting analysis. The increased radial velocity semi-amplitude translates into a system mass function larger than previously deduced (frevised = 2.83 M⊙versus foriginal = 1.42 M⊙). By exploiting the spectral disentangling technique, we place an upper limit of 10 per cent of a luminous primary source to the observed optical light in NGC1850 BH1, assuming that the primary and secondary are the only components contributing to the system. Furthermore, by analysing archival near-infrared data, we find clues to the presence of an accretion disc in the system. These constraints support a low-mass post-mass transfer star but do not provide a definitive answer whether the unseen component in NGC1850 BH1 is indeed a black hole. These results predict a scenario where, if a primary luminous source of mass M ≥ 4.7 M⊙ is present in the system (given the inclination and secondary mass constraints), it must be hidden in a optically thick disc to be undetected in the MUSE spectra.
LRG-BEASTS: evidence for clouds in the transmission spectrum of HATS-46 b
Authors: Ahrer E , Wheatley P J , Gandhi S , Kirk J , King G W , Louden T , Welbanks L
Published: March 2023

We have performed low-resolution ground-based spectroscopy of HATS-46 b in transmission, using the EFOSC2 instrument on the ESO New Technology Telescope (NTT). HATS-46 b is a highly inflated exoplanet that is a prime target for transmission spectroscopy, having a Jupiter-like radius (0.95 RJup) but a much lower mass (0.16 MJup). It orbits a G-type star with a 4.7 d period, giving an equilibrium temperature of 1100 K. We observed one transit of HATS-46 b with the NTT, with the time-series spectra covering a wavelength range of 3900–9000 Å at a resolution (R) of ∼380. We achieved a remarkably precise transmission spectrum of 1.03 × photon noise, with a median uncertainty of 357 ppm for ∼200 Å-wide bins, despite the relative faintness of the host star with Vmag = 13.6. The transmission spectrum does not show strong absorption features and retrievals favour a cloudy model, ruling out a clear atmosphere with 3.0σ confidence. We also place a conservative upper limit on the sodium abundance under the alternative scenario of a clear atmosphere. This is the eighth planet in the LRG-BEASTS (Low-Resolution Ground-Based Exoplanet Atmosphere Survey using Transmission Spectroscopy) survey, which uses 4 m-class telescopes such as the NTT to obtain low-resolution transmission spectra of hot Jupiters with precisions of around one atmospheric scale height.
A preliminary investigation of the empirical relationship between small-amplitude Forbush Decreases and solar wind disturbances
Authors: Menteso F M , Chukwude A E , Okike O , Alhassan J A
Published: March 2023

High-magnitude (amplitude $\le -3{{\ \rm per\ cent}}$) Forbush decreases (FDs) are generally employed by researchers investigating the solar-terrestrial connection mechanisms. Although it has been observed that small-amplitude FDs are relatively important as they may be the outcome of the response of cosmic ray time-intensity variations to solar ejections that generate interplanetary and solar wind plasma disturbances, empirical relations between weak FDs and solar-terrestrial parameters are rarely tested. In an attempt to analyse the suggested strong connections between weak FDs and solar-terrestrial phenomena, we employed some comparatively more efficient, accurate, and highly sensitive versions of the recently developed computer FD event selection software. Large catalogues of low-amplitude (FD(per cent) ≥−3) Forbush events were selected from Apatity, Moscow, Newark, and Oulu NMs. These catalogues allow us to test, for the first time, the empirical relations between small-amplitude FDs and solar wind data. We find significant negative correlations between solar wind speed (SWS) and the small FDs at OULU, NWRK, and MOSC stations. While the relation at OULU is strong and statistically significant at 95 per cent confidence level, the weak correlation at NWRK and MOSC is only significant at a 90 per cent level. The negative correlation between the small events at OULU and the interplanetary magnetic field (IMF) is also significant at the a 95 per cent level. The relation between SWS and IMF and high-amplitude FDs were also tested, and the correlation coefficients were negative, strong, and statistically significant at a 99.9 per cent level of significance.
Bright extragalactic ALMA redshift survey (BEARS) III: detailed study of emission lines from 71Herscheltargets
Authors: Hagimoto M , Bakx T J L C , Serjeant S , Bendo G J , Urquhart S A , Eales S , Harrington K C , Tamura Y , Umehata H , Berta S , Cooray A R , Cox P , De Zotti G , Lehnert M D , Riechers D A , Scott D , Temi P , van der Werf P P , Yang C , Amvrosiadis A , Andreani P M , Baker A J , Beelen A , Borsato E , Buat V , Butler K M , Dannerbauer H , Dunne L , Dye S , Enia A F M , Fan L , Gavazzi R , González-Nuevo J , Harris A I , Herrera C N , Hughes D H , Ismail D , Ivison R J , Jones B , Kohno K , Krips M , Lagache G , Marchetti L , Massardi M , Messias H , Negrello M , Neri R , Omont A , Perez-Fournon I , Sedgwick C , Smith M W L , Stanley F , Verma A , Vlahakis C , Ward B , Weiner C , Weiß A , Young A J
Published: March 2023

We analyse the molecular and atomic emission lines of 71 bright Herschel-selected galaxies between redshifts 1.4 and 4.6 detected by the Atacama Large Millimeter/submillimeter Array. These lines include a total of 156 CO, [C i], and H2O emission lines. For 46 galaxies, we detect two transitions of CO lines, and for these galaxies we find gas properties similar to those of other dusty star-forming galaxy (DSFG) samples. A comparison to photodissociation models suggests that most of Herschel-selected galaxies have similar interstellar medium conditions as local infrared-luminous galaxies and high-redshift DSFGs, although with denser gas and more intense far-ultraviolet radiation fields than normal star-forming galaxies. The line luminosities agree with the luminosity scaling relations across five orders of magnitude, although the star formation and gas surface density distributions (i.e. Schmidt–Kennicutt relation) suggest a different star formation phase in our galaxies (and other DSFGs) compared to local and low-redshift gas-rich, normal star-forming systems. The gas-to-dust ratios of these galaxies are similar to Milky Way values, with no apparent redshift evolution. Four of 46 sources appear to have CO line ratios in excess of the expected maximum (thermalized) profile, suggesting a rare phase in the evolution of DSFGs. Finally, we create a deep stacked spectrum over a wide rest-frame frequency (220–890 GHz) that reveals faint transitions from HCN and CH, in line with previous stacking experiments.
The shape distribution of superclusters in SDSS DR12
Authors: Bag Satadru , Liivamägi Lauri Juhan , Einasto Maret
Published: March 2023

Galaxy superclusters, the largest galaxy structures in the cosmic web, are formed due to the gravitational collapse (although they are not usually gravitationally bound). Their geometrical properties can shed light on the structure formation process on cosmological scales, hence on the fundamental properties of gravity itself. In this work we study the distributions of the shape, topology, and morphology of the superclusters extracted from Sloan Digital Sky Survey Data Release 12 (SDSS DR12) main galaxy sample and defined in two different ways – using fixed and adaptive density threshold in the luminosity-density field. To assess the geometry and topology of each individual supercluster, we employ Minkowski functionals and Shapefinders, precisely calculated by the shape diagnostic tool SURFGEN2. Both supercluster samples produce similar shape distributions. Perhaps not surprisingly, most superclusters are spherical in shape with trivial topology. However, large superclusters with volumes V ≳ 104 Mpc3 are statistically found to be filamentary with non-zero genus values. The results, supercluster catalogues and shape distributions are publicly available.
Unravelling the secrets of blazar OT 081: a multiwavelength investigation
Authors: Deng Junhao , Jiang Yunguo
Published: March 2023

OT 081 is a low-synchrotron-peaked (LSP) frequency blazar target, and has strong emission in the γ-ray band. In July 2016, a significant short-term flare was observed in the optical, X-ray and γ-ray bands. In addition, a long-term orphan flare was observed in the X-ray band from 2009 to 2012. Using the multiwavelength data, we investigate the origin of these two flares and the emission mechanism of γ-ray photons. According to the correlation analysis, we suggest that both flares may have originated from the formation of the new dissipation zones within the jet rather than the change of Doppler factor. The 2016 short-term flare happens on small-scale dissipation zone, while the long-term X-ray flare originates from large scale dissipation zone. Furthermore, we study the spectral energy distribution (SED) to investigate whether the broad-line region (BLR) and the dust torus can provide enough external photons to explain the γ-ray emission of the 2016 flare within the leptonic scenario. We find that the 2016 flare can be explained when the scale of the newly formed dissipation zone is comparable to that of BLR. For the 2009–2012 orphan X-ray flare, we suggest that it may be dominated by the synchrotron self-Compton (SSC) process in a newly formed dissipation zone at pc scale, since both the magnetic field and the external soft photon field energy density are small enough at this region. In summary, the emission mechanism of OT 081 could be explained in the leptonic scenario.
Simulations of pre-supernova feedback in spherical clouds
Authors: Kourniotis M , Wünsch R , Martínez-González S , Palouš J , Tenorio-Tagle G , Ehlerová S
Published: March 2023

We present a 1D radiation-hydrodynamic model of a spherically symmetric cloud evolving under the influence of the self-gravity and the feedback from a star cluster forming in its centre. On one hand, the model is simple due to its 1D geometry, on the other hand, the feedback includes the ionizing radiation, stellar winds and the radiation pressure acting on gas and dust. The star cluster is formed from the gas flowing into the cloud centre and the feedback parameters are determined from stellar evolution models and the cluster star forming history. The model is compared to the semi-analytic code warpfield implementing similar physical processes and exploring the scenario that the young cluster R136 in the Large Magellanic Cloud was formed due to re-collapse of the shell formed by the previous generation star cluster. A good qualitative agreement is found, however, 3−4 times higher stellar mass is needed to disrupt the cloud in our model, because it takes into account (contrary to warpfield) self-gravity of the cloud surrounding the shell. We use the model to explore star formation in clouds with different mass, radius and density profile measuring their star formation efficiency (SFE), i.e. the fraction of the cloud mass converted to stars. We found that SFE is a function of a single parameter, $\mathrm{log(SFE)} \propto -n_{\text{hm}}^{-0.46}$, with nhm being the cloud mean particle density within its half-mass radius. Furthermore, we found that the feedback efficiency, i.e. a fraction of the feedback energy retained by gas, has a nearly constant value ∼10−3.
Evolution of binary stars in the early evolutionary phases of ultra-faint dwarf galaxies
Authors: Livernois Alexander R , Vesperini Enrico , Pavlík Václav
Published: March 2023

The dynamics of binary stars provides a unique avenue to gather insight into the study of the structure and dynamics of star clusters and galaxies. In this paper, we present the results of a set of N-body simulations aimed at exploring the evolution of binary stars during the early evolutionary phases of ultra-faint dwarf galaxies (UFD). In our simulations, we assume that the stellar component of the UFD is initially dynamically cold and evolves towards its final equilibrium after undergoing the violent relaxation phase. We show that the early evolutionary phases of the UFD significantly enhance the disruption of wide binaries and leave their dynamical fingerprints on the semimajor axis distribution of the surviving binaries as compared to models initially in equilibrium. An initially thermal eccentricity distribution is preserved except for the widest binaries for which it evolves towards a superthermal distribution; for a binary population with an initially uniform eccentricity distribution, memory of this initial distribution is rapidly lost for most binaries as wider binaries evolve to approach a thermal/superthermal distribution. The evolution of binaries is driven both by tidal effects due to the potential of the UFD dark matter halo and collisional effects associated to binary–binary/single star encounters. Collisional effects are particularly important within the clumpy substructure characterizing the system during its early evolution; in addition to enhancing binary ionization and evolution of the binary orbital parameters, encounters may lead to exchanges of either of the primordial binary components with one of the interacting stars.
Can we observe the ion-neutral drift velocity in prestellar cores?
Authors: Tritsis Aris , Basu Shantanu , Federrath Christoph
Published: March 2023

Given the low-ionization fraction of molecular clouds, ambipolar diffusion is thought to be an integral process in star formation. However, chemical and radiative-transfer effects, observational challenges, and the fact that the ion-neutral drift velocity is inherently very small render a definite detection of ambipolar diffusion extremely non-trivial. Here, we study the ion-neutral drift velocity in a suite of chemodynamical, non-ideal magnetohydrodynamic (MHD), two-dimensional axisymmetric simulations of prestellar cores where we alter the temperature, cosmic-ray ionization rate, visual extinction, mass-to-flux ratio, and chemical evolution. Subsequently, we perform a number of non-local thermodynamic equilibrium (non-LTE) radiative-transfer calculations considering various idealized and non-idealized scenarios in order to assess which factor (chemistry, radiative transfer, and/or observational difficulties) is the most challenging to overcome in our efforts to detect the ion-neutral drift velocity. We find that temperature has a significant effect in the amplitude of the drift velocity with the coldest modelled cores (T  = 6 K) exhibiting drift velocities comparable to the sound speed. Against expectations, we find that in idealized scenarios (where two species are perfectly chemically co-evolving) the drift velocity ‘survives’ radiative-transfer effects and can in principle be observed. However, we find that observational challenges and chemical effects can significantly hinder our view of the ion-neutral drift velocity. Finally, we propose that $\rm {HCN}$ and $\rm {HCNH^+}$, being chemically co-evolving, could be used in future observational studies aiming to measure the ion-neutral drift velocity.
Wind-fed GRMHD simulations of Sagittarius A*: tilt and alignment of jets and accretion discs, electron thermodynamics, and multiscale modelling of the rotation measure
Authors: Ressler S M , White C J , Quataert E
Published: March 2023

Wind-fed models offer a unique way to form predictive models of the accretion flow surrounding Sagittarius A*. We present 3D wind-fed magnetohydrodynamic (MHD) and general relativistic magnetohydrodynamic (GRMHD) simulations spanning the entire dynamic range of accretion from parsec scales to the event horizon. We expand on previous work by including non-zero black hole spin and dynamically evolved electron thermodynamics. Initial conditions for these simulations are generated from simulations of the observed Wolf–Rayet stellar winds in the Galactic Centre. The resulting flow tends to be highly magnetized (β ≈ 2) with an ∼r−1 density profile independent of the strength of magnetic fields in the winds. Our simulations reach the magnetically arrested disc (MAD) state for some, but not all cases. In tilted flows, standard and normal evolution (SANE) jets tend to align with the angular momentum of the gas at large scales, even if that direction is perpendicular to the black hole spin axis. Conversely, MAD jets tend to align with the black hole spin axis. The gas angular momentum shows similar behaviour: SANE flows tend to only partially align while MAD flows tend to fully align. With a limited number of dynamical free parameters, our models can produce accretion rates, 230 GHz flux, and unresolved linear polarization fractions roughly consistent with observations for several choices of electron heating fraction. Absent another source of large-scale magnetic field, winds with a higher degree of magnetization (e.g. where the magnetic pressure is 1/100 of the ram pressure in the winds) may be required to get a sufficiently large rotation measure with consistent sign.
On the morphology of the gamma-ray galactic centre excess
Authors: McDermott Samuel D , Zhong Yi-Ming , Cholis Ilias
Published: March 2023

The characteristics of the galactic centre excess (GCE) emission observed in gamma-ray energies – especially the morphology of the GCE – remain a hotly debated subject. The manner in which the dominant diffuse gamma-ray background is modelled has been claimed to have a determining effect on the preferred morphology. In this work, we compare two distinct approaches to the galactic diffuse gamma-ray emission background: the first approach models this emission through templates calculated from a sequence of well-defined astrophysical assumptions, while the second approach divides surrogates for the background gamma-ray emission into cylindrical galactocentric rings with free independent normalizations. At the latitudes that we focus on, we find that the former approach works better, and that the overall best fit is obtained for an astrophysically motivated fit when the GCE follows the morphology expected of dark matter annihilation. Quantitatively, the improvement compared with the best ring-based fits is roughly 6500 in the χ2 and roughly 4000 in the log of the Bayesian evidence.
Two-component jet model for multiwavelength afterglow emission of the extremely energetic burst GRB 221009A
Authors: Sato Yuri , Murase Kohta , Ohira Yutaka , Yamazaki Ryo
Published: March 2023

Recently gamma-ray bursts (GRBs) have been detected at very-high-energy (VHE) gamma-rays by imaging atmospheric Cherenkov telescopes, and a two-component jet model has often been invoked to explain multiwavelength data. In this work, multiwavelength afterglow emission from an extremely bright GRB, GRB 221009A, is examined. The isotropic-equivalent gamma-ray energy of this event is among the largest, which suggests that similarly to previous VHE GRBs, the jet opening angle is so small that the collimation-corrected gamma-ray energy is nominal. Afterglow emission from such a narrow jet decays too rapidly, especially if the jet propagates into uniform circumburst material. In the two-component jet model, another wide jet component with a smaller Lorentz factor dominates late-time afterglow emission, and we show that multiwavelength data of GRB 221009A can be explained by narrow and wide jets with opening angles similar to those employed for other VHE GRBs. We also discuss how model degeneracies can be disentangled with observations.
Retrospective examination of pseudoprogression in IDH mutant gliomas
Authors: Wetzel Ethan A , Farrell Matthew J , Eldred Blaine S C , Liu Vicki , Saha Ishan , Zapanta Rinonos Serendipity , Prins Terry , Li Tie , Cao Minsong , Hegde John , Kaprealian Tania , Khanlou Negar , Liau Linda M , Nghiemphu Phioanh Leia , Cloughesy Timothy Francis , Chong Robert A , Ellingson Benjamin M , Lai Albert
Published: March 2023

Background

Tumor surveillance of isocitrate dehydrogenase (IDH) mutant gliomas is accomplished via serial contrast MRI. When new contrast enhancement (CEnew) is detected during postsurgical surveillance, clinicians must assess whether CEnew indicates pseudoprogression (PsP) or tumor progression (TP). PsP has been better studied in IDH wild-type glioblastoma but has not been well characterized in IDH mutant gliomas. We conducted a retrospective study evaluating the incidence, predictors, natural history, and survival of PsP patients in a large cohort of IDH mutant glioma patients treated at a single institution.

Methods

We identified 587 IDH mutant glioma patients treated at UCLA. We directly inspected MRI images and radiology reports to identify CEnew and categorized CEnew into TP or PsP using MRI or histopathology.

Results

Fifty-six percent of patients developed CEnew (326/587); of these, 92/326 patients (28% of CEnew; 16% of all) developed PsP and 179/326 (55%) developed TP. All PsP patients had prior radiation, chemotherapy, or chemoradiotherapy. PsP was associated with longer overall survival (OS) versus TP patients and similar OS versus no CEnew. PsP differs from TP based on earlier time of onset (median 5.8 vs 17.4 months from treatment, P < .0001) and MRI features that include punctate enhancement and enhancement location.

Conclusion

PsP patients represented 28% of CEnew patients and 16% of all patients; PsP patients demonstrated superior outcomes to TP patients, and equivalent survival to patients without CEnew. PsP persists for <1 year, occurs after treatment, and differs from TP based on time of onset and radiographic features. Poor outcomes after CEnew are driven by TP.
Utility of Polymerase Chain Reaction Versus Serology-Based Testing in Immunocompromised Patients With Bartonella henselae Infection
Authors: Kumar Ankit , Abdulqader Mohammed , McBride Darrell A
Published: March 2023

Bartonella henselae serologies can be nondiagnostic in immunocompromised individuals due to impaired humoral immunity. Blood polymerase chain reaction (PCR) is more useful diagnostically in immunosuppressed persons. We discuss 3 cases: 2 solid organ transplant (SOT) recipients and 1 person with human immunodeficiency virus (HIV) with positive blood PCR despite negative serology.
KRAS: Druggable at Last
Authors: Herzberg Benjamin O , Manji Gulam A
Published: March 2023

The approval of adagrasib for non–small cell lung cancer is a milestone in drug development. This commentary highlights the history of the research that led to this breakthrough that will help many patients with KRAS-mutated cancers to live longer and better.
Allelic variation of terpene synthases drives terpene diversity in the wild species of the Freesia genus
Authors: Bao Tingting , Kimani Shadrack , Li Yueqing , Li Hongjie , Yang Song , Zhang Jia , Wang Qiuyue , Wang Zhaoxuan , Ning Guogui , Wang Li , Gao Xiang
Published: March 2023

Terpene synthases (TPSs) play pivotal roles in conferring the structural diversity of terpenoids, which are mainly emitted from flowers, whereas the genetic basis of the release of floral volatile terpenes remains largely elusive. Though quite similar in sequence, TPS allelic variants still function divergently, and how they drive floral terpene diversity in closely related species remains unknown. Here, TPSs responsible for the floral scent of wild Freesia species were characterized, and the functions of their natural allelic variants, as well as the causal amino acid residues, were investigated in depth. Besides the 8 TPSs previously reported in modern cultivars, 7 additional TPSs were functionally evaluated to contribute to the major volatiles emitted from wild Freesia species. Functional characterization of allelic natural variants demonstrated that allelic TPS2 and TPS10 variants changed the enzymatic capacity while allelic TPS6 variants drove the diversity of floral terpene products. Further residue substitution analysis revealed the minor residues determining the enzyme catalytic activity and product specificity. The clarification of TPSs in wild Freesia species reveals that allelic TPS variants evolved differently to determine the interspecific floral volatile terpenes in the genus and might be used for modern cultivar improvement.
The Other Great Migration: Southern Whites and the New Right
Authors: Bazzi Samuel , Ferrara Andreas , Fiszbein Martin , Pearson Thomas , Testa Patrick A
Published: March 2023

This article shows how the migration of millions of Southern whites in the twentieth century shaped the cultural and political landscape across the United States. Racially and religiously conservative, Southern white migrants created new electoral possibilities for a broad-based coalition with economic conservatives. With their considerable geographic scope, these migrants hastened partisan realignment and helped catalyze and bolster a New Right movement with national influence over the long run. More than just augmenting the conservative voter base outside the South, they influenced non-Southerners by building evangelical churches, diffusing right-wing media, and mixing through intermarriage and residential integration. Tracking non-Southern households, we show that exposure to Southern white neighbors increased adoption of conservative religious norms. Overall, our findings suggest that this mass migration blurred the North–South cultural divide and reshaped the geography of conservatism in the United States.
Cultural Distance and Conflict-Related Sexual Violence
Authors: Guarnieri Eleonora , Tur-Prats Ana
Published: March 2023

This article examines the relationship between ethnic-based gender norms and conflict-related sexual violence. We generate a novel dyadic data set that contains information on the ethnic identity of all the actors involved in ethnic civil conflicts around the world between 1989 and 2019 and their use of sexual violence. We exploit ethnographic information to construct a new male dominance index at the ethnicity level that captures deep-rooted gender norms. First, we find that male-dominant armed actors are more likely to be perpetrators of sexual violence. Second, we consider the cultural distance in gender norms between the combatants and show that sexual violence is driven by a specific clash of conceptions on the appropriate role of men and women in society: sexual violence increases when the perpetrator is more male dominant than the victim. Additional analyses suggest that gender norms influence both the strategic use of sexual violence for military purposes and the expressive use of sexual violence for private motivations. These patterns are specific to sexual violence and do not explain general violence in a conflict. Differences in other cultural dimensions unrelated to gender are not associated with conflict-related sexual violence.
The Religious Imaginary and the Repressive State: Science-based Beliefs of Ukrainian and Lithuanian Scientists Born in the USSR
Authors: Rogińska Maria
Published: March 2023

The article explores aspects of the Soviet atheistic regime that contributed to the formation of the religious imaginary of believing Ukrainian and Lithuanian scientists born in 1930–1960s. After the collapse of the Soviet Union, most of them did not accept Orthodox, Catholic, or other institutional religions, but instead created their own privatized religious patterns, using science-related elements in their imaginary. This distinguished them from the other national groups participating in the study. In the article, I propose an interpretation for this phenomenon. I analyze 29 in-depth interviews of a larger sample and focus on the biographies of the older cohort of natural scientists from Lithuania and Ukraine to show how the Soviet political and normative context supported their science-based imaginary. This allows us to draw some parallels concerning secularization—gradual in the West but forced in the Soviet case—and the role of science in this process.
Improving high school students’ perceptions of mathematics through a mathematical modelling course
Authors: Spooner Kerri , Nomani Junior , Cook Samantha
Published: March 2023

Literature shows there is support for adding connection and relevancy in mathematics for students through the use of real-world context and data in mathematical modelling. A teaching unit on mathematical modelling was designed within the context of future affordable housing for the local surrounding area. The teaching unit was implemented, and data were collected to address the research question: ‘How does exposure to mathematical modelling influence students’ perceptions and understandings of mathematical modelling?’ Data were collected through pre- and post-teaching unit surveys and post-teaching unit student interviews. Pre- and post-surveys were used to establish any changes in students’ perception towards mathematics, understanding of mathematical modelling and perceived relevance of mathematical modelling use to their own lives. Student interviews gained further insight into the student experience and associated perception changes. Statistical analysis of the survey responses included both hypothesis and nonparametric testing. Interviews were analysed using a thematic qualitative approach. Our analysis showed that a greater understanding of mathematical modelling was achieved, with many students unfamiliar with the concept prior to the teaching unit. It was also found that through the real-world context of the mathematical modelling unit, students had a new-found interest in mathematics.
Examining the characteristics between time and distance gaps of secondary crashes
Authors: Liu Xinyuan , Tang Jinjun , Yuan Chen , Gao Fan , Ding Xizhi
Published: March 2023

Understanding the characteristics of time and distance gaps between the primary (PC) and secondary crashes (SC) is crucial for preventing SC ccurrences and improving road safety. Although previous studies have tried to analyse the variation of gaps, there is limited evidence in quantifying the relationships between different gaps and various influential factors. This study proposed a two-layer stacking framework to discuss the time and distance gaps. Specifically, the framework took random forests (RF), gradient boosting decision tree (GBDT) and eXtreme gradient boosting as the base classifiers in the first layer and applied logistic regression (LR) as a combiner in the second layer. On this basis, the local interpretable model-agnostic explanations (LIME) technology was used to interpret the output of the stacking model from both local and global perspectives. Through SC dentification and feature selection, 346 SCs and 22 crash-related factors were collected from California interstate freeways. The results showed that the stacking model outperformed base models evaluated by accuracy, precision, and recall indicators. The explanations based on LIME suggest that collision type, distance, speed and volume are the critical features that affect the time and distance gaps. Higher volume can prolong queue length and increase the distance gap from the SCs to PCs. And collision types, peak periods, workday, truck involved and tow away likely induce a long-distance gap. Conversely, there is a shorter distance gap when secondary roads run in the same direction and are close to the primary roads. Lower speed is a significant factor resulting in a long-time gap, while the higher speed is correlated with a short-time gap. These results are expected to provide insights into how contributory features affect the time and distance gaps and help decision-makers develop accurate decisions to prevent SCs.