bluuebunny/crossref_metadata_2025 huggingface dataset:
Mapping the Galactic Disk with the LAMOST and Gaia Red Clump Sample. V. On the Origin of the “Young” [α/Fe]-enhanced Stars
Authors: Sun W.-X. , Huang Y. , Wang H.-F. , Wang C. , Zhang M. , Li X.-Y. , Chen B.-Q. , Zhang H.-W. , Wei D.-D. , Jiang D.-K. , Liu X.-W.
Published: October 2020

Using a sample of nearly 140,000 primary red-clump stars selected from the LAMOST and Gaia surveys, we have identified a large sample of “young” [α/Fe]-enhanced stars with stellar ages younger than 6.0 Gyr and [α/Fe] ratios greater than 0.15 dex. The stellar ages and [α/Fe] ratios are measured from LAMOST spectra, using a machine-learning method trained with common stars in the LAMOST–APOGEE fields (for [α/Fe]) and in the LAMOST–Kepler fields (for stellar age). The existence of these “young” [α/Fe]-enhanced stars is not expected from the classical Galactic chemical evolution models. To explore their possible origins, we have analyzed the spatial distribution, and the chemical and kinematic properties of those stars and compared the results with those of the chemically thin and thick disk populations. We find that those “young” [α/Fe]-enhanced stars have distributions in number density, metallicity, [C/N] abundance ratio, velocity dispersion, and orbital eccentricity that are essentially the same as those of the chemically thick disk population. Our results clearly show those so-called “young” [α/Fe]-enhanced stars are not really young but genuinely old. Although other alternative explanations can not be fully ruled out, our results suggest that the most possible origin of these old stars is the result of stellar mergers or mass transfer.
Testing a Data-driven Active Region Evolution Model with Boundary Data at Different Heights from a Solar Magnetic Flux Emergence Simulation
Authors: Jiang Chaowei , Toriumi Shin
Published: October 2020

A data-driven active region evolution (DARE) model has been developed to study the complex structures and dynamics of solar coronal magnetic fields. The model is configured with a typical coronal environment of tenuous gas governed by strong magnetic field, and thus its lower boundary is set at the base of the corona, but driven by magnetic fields observed in the photosphere. A previous assessment of the model using data from a flux emergence simulation (FES) showed that the DARE failed to reproduce the coronal magnetic field in the FES, which is attributed to the fact that the photospheric data in the FES has a very strong Lorentz force and therefore spurious flows are generated in the DARE model. Here we further test the DARE by using three sets of data from the FES sliced at incremental heights, which correspond to the photosphere, the chromosphere, and the base of the corona. It is found that the key difference in the three sets of data is the extent of the Lorentz force, which makes the data-driven model perform very differently. At the two higher levels above the photosphere, the Lorentz force decreases substantially, and the DARE model attains results in much better agreement with the FES, confirming that the Lorentz force in the boundary data is a key issue affecting the results of the DARE model. However, unlike the FES data, the photospheric field from SDO/HMI observations has recently been found to be very close to force-free. Therefore, we suggest that it is still reasonable to use the photospheric magnetic field as an approximation of the field at the coronal base to drive the DARE model.
MAGICal GRB 190114C: Implications of Cutoff in the Spectrum at sub-GeV Energies
Authors: Chand Vikas , Pal Partha Sarathi , Banerjee Ankush , Sharma Vidushi , Tam P. H. T. , He Xinbo
Published: October 2020

GRB 190114C is an unusual gamma-ray burst (GRB) due to its detection at sub-TeV energies by MAGIC, seen at redshift z = 0.42. This burst is one of the brightest GRB detected by Fermi. A joint GBM-LAT analysis of the prompt emission reveals the presence of sub-GeV spectral cutoff when the LAT low-energy event (LLE) data is also examined. A similar high-energy cutoff was likewise reported in GRB 160509A and GRB 100724B earlier, as well as a handful of other sources. The cutoff can be explained by the intrinsic opacity due to pair production within the emitting region. GRB 190114C shows a transition from nonthermal to a quasi-thermal-like spectrum and a radiation component that can be attributed to afterglow. Based on spectral analysis, we constrain the site of the prompt emission and Lorentz factor. Knowing that sub-TeV photons are detected in MAGIC, we perceive that the observed spectrum is indeed an overlap from two emission sites, where the emission observed in Fermi is more consistent with prompt emission produced via photospheric dissipation along with a concurrent component from the external shock.
Dynamics of Colombo’s Top: Generating Exoplanet Obliquities from Planet–Disk Interactions
Authors: Su Yubo , Lai Dong
Published: October 2020

Large planetary spin–orbit misalignments (obliquities) may strongly influence atmospheric circulation and tidal heating in a planet. A promising avenue to generate obliquities is via spin–orbit resonances, where the spin and orbital precession frequencies of a planet cross each other as the system evolves in time. One such mechanism involves a dissipating (mass-losing) protoplanetary disk that drives orbital precession of an interior planet. We study this scenario analytically in this paper, and obtain the mapping between the general initial spin orientation and the final obliquity. We show that (i) under adiabatic evolution (i.e., the disk dissipates at a sufficiently slow rate), the final planetary obliquity as a function of the initial spin orientation bifurcates into distinct tracks governed by interactions with the resonance; and (ii) under nonadiabatic evolution, a broad range of obliquities can be excited. We obtain analytical expressions for the final obliquities for various regimes of parameter space. The dynamical system studied in this paper is an example of “Colombo’s top,” and our analysis and results can be adapted to other applications.
Probing the Physics of Mechanical AGN Feedback with Radial Elongations of X-Ray Cavities
Authors: Guo Fulai
Published: October 2020

Mechanical active galactic nucleus (AGN) feedback plays a key role in massive galaxies, galaxy groups, and clusters. However, the energy content of AGN jets that mediate this feedback process is still far from clear. Here we present a preliminary study of radial elongations τ of a large sample of X-ray cavities, which are apparently produced by mechanical AGN feedback. All of the cavities in our sample are elongated along the angular (type I) or jet directions (type II), or nearly circular (type III). The observed value of τ roughly decreases as the cavities rise buoyantly, confirming the same trend found in hydrodynamic simulations. For young cavities, both type-I and type-II cavities exist, and the latter dominates. Assuming a spheroidal cavity shape, we derive an analytical relation between the intrinsic radial elongation

and the inclination-angle-dependent value of τ, showing that projection effect makes cavities appear more circular, but does not change type-I cavities into type-II ones, or vice versa. We summarize radial elongations of young cavities in simulations, finding that

increases with the kinetic fraction of AGN jets. While mild jets always produce type-II cavities, thermal-energy-dominated strong jets produce type-I cavities, and kinetic-energy-dominated strong jets produce type-II cavities. Our results suggest that some AGN jets are strong and dominated by thermal energy (or cosmic rays). However, these jets do not dominate in AGN feedback. If most jets are dominated by nonkinetic energies, they should be mainly mild jets. If most jets are strong, they must be mainly dominated by the kinetic energy.
The Origin of Switchbacks in the Solar Corona: Linear Theory
Authors: Zank G. P. , Nakanotani M. , Zhao L.-L. , Adhikari L. , Kasper J.
Published: October 2020

The origin, structure, and propagation characteristics of a switchback are compelling questions posed by Parker Solar Probe (PSP) observations of velocity spikes and magnetic field reversals. By assuming interchange reconnection between coronal loop and open magnetic field, we show that this results in the generation of upward (into the heliosphere) and downward complex structures propagating at the fast magnetosonic speed (i.e., the Alfvén speed in the low plasma beta corona) that can have an arbitrary radial magnetic field deflection, including “S-shaped.” We derive the evolution equation for the switchback radial magnetic field as it propagates through the inhomogeneous supersonic solar corona. An analytic solution for arbitrary initial conditions is used to investigate the properties of a switchback propagating from launch ∼6 to ∼35 R
⊙ where PSP observed switchbacks during its first encounter. We provide a detailed comparison to an example event, showing that the magnetic field and plasma solutions are in accord with PSP observations. For a simple single switchback, the model predicts either a single or a double-humped structure; the former corresponding to PSP observing either the main body or the flanks of the switchback. The clustering of switchbacks and their sometimes complicated structure may be due to the formation of multiple closely spaced switchbacks created by interchange reconnection with numerous open and loop magnetic field lines over a short period. We show that their evolution yields a complex, aggregated group of switchbacks that includes “sheaths” with large-amplitude radial magnetic field and velocity fluctuations.
Spitzer Reveals Evidence of Molecular Absorption in the Atmosphere of the Hot Neptune LTT 9779b
Authors: Dragomir Diana , Crossfield Ian J. M. , Benneke Björn , Wong Ian , Daylan Tansu , Diaz Matias , Deming Drake , Molliere Paul , Kreidberg Laura , Jenkins James S. , Berardo David , Christiansen Jessie L. , Dressing Courtney D. , Gorjian Varoujan , Kane Stephen R. , Mikal-Evans Thomas , Morales Farisa Y. , Werner Michael , Ricker George R. , Vanderspek Roland , Seager S. , Winn Joshua N. , Jenkins Jon M. , Colón Knicole D. , Fong Willie , Guerrero Natalia , Hesse Katharine , Osborn Hugh P. , E. Rose Mark , Smith Jeffrey C. , Ting Eric B.
Published: October 2020

Non-rocky sub-Jovian exoplanets in high-irradiation environments are rare. LTT 9779b, also known as Transiting Exoplanet Survey Satellite (TESS) object of interest (TOI) 193.01, is one of the few such planets discovered to date, and the first example of an ultrahot Neptune. The planet’s bulk density indicates that it has a substantial atmosphere, so to investigate its atmospheric composition and shed further light on its origin, we obtained Spitzer InfraRed Array Camera secondary eclipse observations of LTT 9779b at 3.6 and 4.5 μm. We combined the Spitzer observations with a measurement of the secondary eclipse in the TESS bandpass. The resulting secondary eclipse spectrum strongly prefers a model that includes CO absorption over a blackbody spectrum, incidentally making LTT 9779b the first TESS exoplanet (and the first ultrahot Neptune) with evidence of a spectral feature in its atmosphere. We did not find evidence of a thermal inversion, at odds with expectations based on the atmospheres of similarly irradiated hot Jupiters. We also report a nominal dayside brightness temperature of 2305 ± 141 K (based on the 3.6 μm secondary eclipse measurement), and we constrained the planet’s orbital eccentricity to e < 0.01 at the 99.7% confidence level. Together with our analysis of LTT 9779b’s thermal phase curves reported in a companion paper, our results set the stage for similar investigations of a larger sample of exoplanets discovered in the hot-Neptune desert, investigations that are key to uncovering the origin of this population.
Phase Curves of Hot Neptune LTT 9779b Suggest a High-metallicity Atmosphere
Authors: Crossfield Ian J. M. , Dragomir Diana , Cowan Nicolas B. , Daylan Tansu , Wong Ian , Kataria Tiffany , Deming Drake , Kreidberg Laura , Mikal-Evans Thomas , Gorjian Varoujan , Jenkins James S. , Benneke Björn , Collins Karen A. , Burke Christopher J. , Henze Christopher E. , McDermott Scott , Mireles Ismael , Watanabe David , Wohler Bill , Ricker George , Vanderspek Roland , Seager Sara , Jenkins Jon M.
Published: October 2020

Phase-curve measurements provide a global view of the composition, thermal structure, and dynamics of exoplanet atmospheres. Although most of the dozens of phase-curve measurements made to date are of large, massive hot Jupiters, there is considerable interest in probing the atmospheres of the smaller planets that are the more typical endproduct of the planet formation process. One such planet that is favorable for these studies is the ultrahot Neptune LTT 9779b, a rare denizen of the Neptune desert. A companion paper presents the planet’s secondary eclipses and dayside thermal emission spectrum; in this work we describe the planet’s optical and infrared phase curves, characterized using a combination of Spitzer and Transiting Exoplanet Survey Satellite (TESS) photometry. We detect LTT 9779b’s thermal phase variations at 4.5 μm, finding a phase amplitude of 358 ± 106 ppm and no significant phase offset, with a longitude of peak emission occurring −10° ± 21° east of the substellar point. Combined with our secondary eclipse observations, these phase-curve measurements imply a 4.5 μm dayside brightness temperature of 1800 ± 120 K, a nightside brightness temperature of 700 ± 430 K (<1350 K at 2σ confidence), and a day–night brightness temperature contrast of 1110 ± 460 K. We compare our data to the predictions of 3D general circulation models calculated at multiple metallicity levels and to similar observations of hot Jupiters experiencing similar levels of stellar irradiation. Though not conclusive, our measurement of its small 4.5 μm phase offset, the relatively large amplitude of the phase variation, and the qualitative differences between our target’s dayside emission spectrum and those of hot Jupiters of similar temperatures all suggest a supersolar atmospheric metallicity for LTT 9779b, as might be expected given its size and mass. Finally, we measure the planet’s transits at both 3.6 μm and 4.5 μm, providing a refined ephemeris (P = 0.79207022 ± 0.00000069 days, T
0 = 2458783.51636 ± 0.00027, BJDTDB) that will enable efficient scheduling of future observations to further characterize the atmosphere of this intriguing planet.
Gryon ancinla Kozlov & Lê (Hymenoptera: Scelionidae): host association, expanded distribution, redescription and a new synonymy
Authors: Chen Huayan , Talamas Elijah , Bon Marie-Claude , Moore Matthew
Published: October 2020

Gryon Haliday (Platygastroidea: Scelionidae) is a cosmopolitan genus of egg-parasitoid wasps primarily associated with Heteroptera.

Gryon ancinla Kozlov & Lê is reported for the first time outside of Vietnam, in China and Cambodia, and as an egg parasitoid of the pestiferous leaf-footed bug, Acanthocoris scaber (L.). Gryon ancinla is redescribed based on recently collected specimens and compared to closely related species of Gryon in the region. Gryon clavaerus Kozlov & Lê is treated as a junior synonym and some characters found in the charon species group are discussed.
A database of weed plants in the European part of Russia
Authors: Tretyakova Alyona , Grudanov Nickolay , Kondratkov Pavel , Baranova Olga , Luneva Natalya , Mysnik Yevgenia , Khasanova Gulnaz , Yamalov Sergey , Lebedeva Maria
Published: October 2020

Weeds are plants that, although not specially cultivated, grow and often adapt to growing in arable lands. They form an ecological variant of flora, as a historically-formed set of species growing on cultivated soils. For the rational use of the chemical and biological crop protection products and to produce safe and high-quality food, up-to-date data on the floristic diversity of weeds and the patterns of its geographical change are required. The need for a weeds' database arises that allows many specialists to work together independently. However, the great value of any database lies not in its existence, but in the accumulation of data that can be used to analyse the factors affecting the species diversity of weeds.

A dataset of weed species diversity and their distribution in the European part of Russia, based on the results of the authors' own research from 1999 to 2019, has been created.

The dataset includes 24,284 observations of occurrences of weed plants, which were obtained on the basis of 2,049 relevés of segetal plant communities in seven regions of the European part of Russia. In total, the dataset includes information about 329 species of vascular plants growing in 65 farmlands: cereals, spring and winter crops, industrial crops, row crops and perennial grasses (Tretyakova et al. 2020).
Escape to Create an Interactive and Engaging Learning Experience
Authors: Kinlaw Tabitha S.
Published: October 2020

The American Nurses Credentialing Center and the Association for Nursing Professional Development purport the significance of active learner engagement and its positive effects on learner outcomes. This article describes the development and implementation of an escape room in the perioperative setting to support active learner engagement and enhance learner outcomes.

[
J Contin Educ Nurs
. 2020;51(11):493–495.]
Employment and Retention of Nurses Who Completed an Internship and Residency Program
Authors: Hernandez Stephen H.A. , Francis Marisa A. , Winn Donna
Published: October 2020

Background:

The University of New Mexico Hospitals (UNMH) nurse residency and UNM College of Nursing nurse internship programs began in 2003 and 2004, respectively. This study evaluated the effectiveness of these programs in increasing RN hiring and retention.

Method:

Existing data from academic and human resources records were analyzed. Differences between demographic characteristics were assessed using descriptive statistics, and differences between groups were assessed with chi-square tests.

Results:

Of 472 interns, 85.6% were hired by the UNMH. After 1 year, 341 continued their employment. Of RNs (
n
= 203) who could have been employed for 5 years, 43.3% remained at the UNMH. There were no differences in initial and 1-year RN employment based on age, gender, race, or ethnicity. RNs employed for 5 years were more likely to be male.

Conclusion:

The nurse internship program provided students with experience, knowledge, skills, and income. The UNMH hired graduate nurses and increased employee retention.

[
J Contin Educ Nurs
. 2020;51(11):504–508.]
Optimizing Visualization of Membranes in Macular Surgery With Heads-Up Display
Authors: Melo Alline G.R. , Conti Thais F. , Hom Grant L. , Greenlee Tyler E. , Cella Wener P. , Talcott Katherine E. , Rachitskaya Aleksandra , Yuan Alex , Sood Arjun , Milam Ronald , Arepalli Sruthi , Mendel Thomas , Muralha Felipe P. , Pereira Felipe , Conti Felipe F. , Ciongoli Marina R. , Barbosa Thaisa S. , Linhares Luciana L. , Singh Rishi P.
Published: October 2020

BACKGROUND AND OBJECTIVE:

To determine which optical parameter profiles (OPPs) can be utilized to improve the visualization of epiretinal membranes (ERMs) and the internal limiting membrane (ILM) using a three-dimensional heads-up microscope during 25-gauge pars plana vitrectomy.

PATIENTS AND METHODS:

Fourteen independent graders were asked to complete a questionnaire comparing each of the OPPs against the unaltered control image for each given surgical case.

RESULTS:

Analysis of the graders' responses indicated that higher values of hue are correlated with better visualization of ERM/ILM before and after dye application. There was overall agreement that OPPs could be used to enhance the visualization of the ERM and ILM during surgery.

CONCLUSIONS:

The use of OPPs to improve the visualization of specific structures is still new and heavily dependent on surgeon preference. The authors' study shows that some OPPs may enhance the visualization of the ERM and ILM during macular surgery.

[
Ophthalmic Surg Lasers Imaging Retina.
2020;51:584–587.]
Familial Exudative Vitreoretinopathy With Neurodevelopmental Delay and Hypoplasia of the Corpus Callosum
Authors: Amorelli Giulia M. , Barresi Costanza , Ji Marco H. , Orazi Lorenzo , Molle Fernando , Lepore Domenico
Published: October 2020

A 2-year-old child was referred to the authors' pediatric retina service for bilateral retinal folds, strabismus, and psychomotor retardation, as well as marked thinning of the corpus callosum. Family history was unremarkable and genetic testing revealed a previously undescribed mutation in the
LRP5
gene. Widefield fundus photography, fluorescein angiography, and spectral-domain optical coherence tomography were used to image the retinal fundus. The authors' case suggests a correlation between
LRP5
and neurological development, since its variants may lead to a syndromic condition characterized by FEVR-like abnormalities along with neurodevelopmental delay and hypoplasia of the corpus callosum.

[
Ophthalmic Surg Lasers Imaging Retina.
2020;51:588–591.]
Unilateral Terson-Like Syndrome in a Patient With a Perinatal Ischemic Stroke
Authors: Ebert Jared J. , Varma Hersh , Sisk Robert A.
Published: October 2020

Terson syndrome typically presents with bilateral hemorrhagic retinopathy associated with acute intracranial bleeding. The authors present a case of neonatal hemispheric ischemic stroke with vasogenic edema and increased intracranial pressure creating a unilateral Terson-like syndrome. Magnetic resonance imaging indicated congenital occlusion of the left internal carotid artery, among other vascular abnormalities. Chronic submacular, peripheral subretinal, and vitreous hemorrhage were observed, suggesting a multilaminar hemorrhagic process resembling Terson syndrome without frank intracranial hemorrhage. The patient underwent successful lens-sparing vitrectomy of the left eye. A unilateral Terson-like syndrome can result from severe cerebral edema following neonatal stroke in the setting of multiple congenital cerebrovascular abnormalities.

[
Ophthalmic Surg Lasers Imaging Retina.
2020;51:592–595.]
Recuperación post-nihilista de la intimidad corporal y la persona humana a partir de Nietzsche y Conill
Authors: García-Granero Marina
Published: October 2020

El objetivo de este trabajo es poner en relación el núcleo crítico de la última obra de Jesús Conill, Intimidad corporal y persona humana. De Nietzsche a Ortega y Zubiri, con la problemática del nihilismo, como estructura que pervive en nuestras sociedades contemporáneas, en especial, en el contexto de las neurociencias, la tecnología y nuestro modo de relación con ambas. Tras bosquejar a modo de presentación las idea clave del libro, en especial su innovadora concepción de la intimidad corporal, recuperaré algunas aportaciones de la tematización nietzscheana del nihilismo, para mostrar, en tercer lugar, que tras la “muerte de Dios” otras instancias toman su lugar, y que las lógicas del nihilismo permanecen intactas y subyacentes en la aproximación mayoritaria de las neurociencias. Concluiré que los elementos que presenta Conill para una intimidad y subjetividad fuerte serán necesarios para la tarea, aún pendiente, de superación del nihilismo.
Interior ecosystem in the subarctic: wild, living, arthropod biodiversity in the University of Alaska Museum, Fairbanks, Alaska, United States of America
Authors: Sikes Derek S. , Callegari Kyle
Published: October 2020

Outside of pest control reports, little attention has been paid to interior ecosystems in high-latitude regions. Opportunistic sampling of live arthropods captured inside the University of Alaska Museum Fairbanks, Alaska, United States of America allowed us to describe and analyse one such interior ecosystem. We document a minimum of 77 arthropod species over 18 years. Beetles, spiders, and booklice represented 80% of the total abundance. Of those captured, synanthropes consisted primarily of fungivores and detritivores, seasonals consisted primarily of predators and omnivores, and transients consisted primarily of predators and had greater diet and species diversity than the synanthropes and transients. January was the most common month for capturing synanthropes, September for capturing seasonals, and July for capturing transients. Four synanthropic species not previously known from Alaska, which appear to have breeding populations inside the museum, were found: Dorypteryx domestica (Smithers, 1958) (Psocodea: Psyllipsocidae), Cartodere constricta (Gyllenhal, 1827), Dienerella filum (Aubé, 1850), and Corticaria serrata (Paykull 1800) (Coleoptera: Latridiidae). Three transient and one synanthrope species previously unreported from Alaska, with no evidence of breeding populations, were also found: the click beetle Danosoma obtectum (Say, 1839) (Coleoptera: Elateridae), a spider in the genus Phantyna, probably the species P. bicornis (Emerton, 1915) (Araneae: Dictynidae), two Colobopsis sp. ant specimens (Hymenoptera: Formicidae), and the synanthropic spider Oecobius cellariorum (Dugès, 1836) (Araneae: Oecobiidae).
[Confirmed breeding of Aquila chrysaetos in Pratomagno Massif (western Tuscany)]
Authors: Campedelli Tommaso , Manganelli Marco , Londi Guglielmo , Ridente Davide , Cutini Simonetta , Petrizzelli Lorenzo , Florenzano Guido Tellini
Published: October 2020

[This short note provides the first ever evidence of the successful breeding of the Golden eagle Aquila chrysaetos in the Pratomagno massif, an “anti-Appenines” mountain chain straddling the provinces of Florence and Arezzo (Tuscany), outside the known breeding area. The couple have successfully nested three years after its first observation; in previous years the appearance of the species had become more regular].

 

[Article in Italian]
Birds of Cyprus
Authors: Ferlini Flavio
Published: October 2020

Not available
A Field Guide to the Birds of Mongolia and Birds of Mongolia
Authors: Ferlini Flavio
Published: October 2020

Not Available
Embedding fractals in Banach, Hilbert or Euclidean spaces
Authors: Banakh Taras , Nowak Magdalena , Strobin Filip
Published: October 2020

By a
metric fractal
we understand a compact metric space

K

endowed with a finite family

\mathcal F

of contracting self-maps of

K

such that

K=\bigcup_{f\in\mathcal F}f(K)

. If

K

is a subset of a metric space

X

and each

f\in\mathcal F

extends to a contracting self-map of

X

, then we say that

(K,\mathcal F)

is a fractal in

X

. We prove that each metric fractal

(K,\mathcal F)

is

We prove that for a metric fractal

(K,\mathcal F)

with the doubling property there exists

k\in\mathbb N

such that the metric fractal

(K,\mathcal F^{\circ k})

endowed with the fractal structure

\mathcal F^{\circ k}=\{f_1\circ\dots\circ f_k:f_1,\dots,f_k\in\mathcal F\}

is equi-Hölder equivalent to a fractal in a Euclidean space

\mathbb R^d

. This result is used to prove our main result saying that each finite-dimensional compact metrizable space

K

containing an open uncountable zero-dimensional space

Z

is homeomorphic to a fractal in a Euclidean space

\mathbb R^d

. For

Z

, being a copy of the Cantor set, this embedding result was proved by Duvall and Husch in 1992.
On Hausdorff dimension of radial projections
Authors: Liu Bochen
Published: October 2020

For any

x\in\mathbb{R}^d

,

d\geq 2

, denote by

\pi^x\colon \mathbb{R}^d\backslash\{x\}\rightarrow S^{d-1}

the radial projection

\pi^x(y)=\frac{y-x}{|y-x|}\cdot

Given a Borel set

E\subset\mathbb R^d

with

\mathrm{dim}_{\mathcal{H}} E\leq d-1

, in this paper we investigate for how many

x\in \mathbb{R}^d

the radial projection

\pi^x

preserves the Hausdorff dimension of

E

, namely whether

\mathrm{dim}_{\mathcal{H}}\pi^x(E)=\mathrm{dim}_{\mathcal{H}} E

. We develop a general framework to link

\pi^x(E)

,

x\in F

, and

\pi^y(F)

,

y\in E

, for any Borel set

F\subset\mathbb{R}^d

. In particular, this allows us to apply Orponen's estimate on visibility to study whether

\mathrm {dim}_{\mathcal{H}}\pi^x(E)=\mathrm{dim}_{\mathcal{H}}E

for some

x\in F

. More precisely, we show

\mathrm{dim}_{\mathcal{H}}\{x\in\mathbb{R}^d: \mathrm {dim}_{\mathcal{H}}\pi^x(E) < \mathrm {dim}_{\mathcal{H}}E\}\leq 2(d-1)-\mathrm {dim}_{\mathcal{H}}E,

for any Borel set

E\subset\mathbb R^d

\n{with}

\mathrm{dim}_{\mathcal{H}} E\in(d-2, d-1]

. This improves the Peres–Schlag bound when

\mathrm{dim}_{\mathcal{H}} E\in(d-{3}/{2}, d-1]

, and it is optimal at the endpoint

\mathrm{dim}_{\mathcal{H}} E=d-1

.
Топологическая классификация интегрируемых геодезических биллиардов на квадриках в трeхмерном евклидовом пространстве
Authors: Belozerov Gleb Vladimirovich
Published: October 2020

Рассматриваются геодезические биллиарды на квадриках в $\mathbb{R}^3$. Рассматривается движение материальной точки внутри биллиардного стола, т.е. внутри области, лежащей на квадрике, ограниченной конечным числом квадрик, софокусных с данной, и имеющей углы излома на границе, равные ${\pi}/{2}$. Данная задача оказалась интегрируемой в силу известной теоремы Якоби-Шаля. На множестве биллиардных столов введено отношение эквивалентности и доказана теорема об их классификации. Представлена полная классификация геодезических биллиардов на квадриках в $\mathbb{R}^3$ с точностью до лиувиллевой эквивалентности.
Библиография: 19 названий.
Women in leadership: Interrogating associated covert and overt Paranoia
Authors: Chukwu-Okoronkwo Samuel O.
Published: October 2020

The issue of gender and leadership, especially of women in leadership, has undoubtedly remained a crucial subject matter of discussion in contemporary politics and leadership not only in Africa, but globally too. Scholars have made several attempts to express their different shades of opinions regarding the issue based on their individual consciousness and understanding of the issue as the case may be. This has thus given rise to the prevailing scale of mixed feelings that always surround discussions about the issue; thus entrenching a strong feeling of paranoia about it. Through qualitative research approach, explored through observation and analytical literature review, and further anchored on the Functional Leadership Theory, the paper interrogates the covert and overt manifestations of the feeling of paranoia that often attend the issue of women in leadership generally. It makes a case for not only integrating women in leadership positions in every sphere of life in the society, but also in giving them a chance at the top where it really matters.

Keywords: Gender, Leadership, Male Chauvinism, Paranoia, Patriarchy, Politics, Women
Igala proverbs as correctional tools in the hands of traditional elders
Authors: Sule Sunday Emah , Ojonugwa Sunday Joseph , Akanya Joseph
Published: October 2020

Igala proverbs play a very important role in everyday language of the Igala people. The language has beautiful proverbs which cover all aspects of the people’s life and culture. These proverbs are drawn from careful observation of social events, the lives of people and animals. Also, some proverbs have traces of experiences of the people’s occupations such as farming, fishing, hunting, weaving, wrestling and dancing. The language has proverbs that talk above family and human relations, good and evil, poverty and riches, joy and sorrow. It is on this basis that this study examines how the elders/traditional leaders who are custodians of Igala cultural values use proverbs as a generalized code for establishing standards in ethical and moral values, enthroning respect for elders and constituted authorities and discouraging the youths from embracing social vices prevalent in our society. This study adopts Dan Sperber’s and Wilson’s (1986) relevance theory. Participant observation and interview were the means of data collection. The data collected were analyzed using descriptive and analytical tools. The work uses the traditional contexts of Ogugu and Ankpa proverbs to present their epistemological significance in Igala kingdom.

Keywords: Igala Proverbs, Correctional Tools, Traditional Elders, Relevance Theory, Traditional Institutions
Assessing Nigerian political leadership with a democratic paradigm
Authors: Uzondu Ignatius C.
Published: October 2020

A sober reflection or speculation on African leadership portrays the practice of authentic democracy as a perennial problem in Nigeria and in African continent. Democratic/electoral process is where citizens choose representatives in government by means of free, fair, contested and regularly scheduled elections and where adults have the right to vote and their votes count. But Nigerian democracy lacks basic trust. It is really a universal problem but Africans and Nigerians in particular got larger portion as our democratic practice is very poor. The citizens should be the starting point and focus of democracy, but this is not the case in Nigeria as many political and elected elites represent their business interest. This democratic deficit or deficiency is seen in local, state and federal levels of Nigerian government and this leads gradually to a serious decline in citizen’s active participation or active citizenship. Using expository and analytic method of inquiry, we found out that Nigerians and Africans may have been drifting from this form of government due to some of its demerit. Again, Africa has been long known for its communitarian living/communalism which we found to have enormous similarities with democracy though the difference is clear. Corruption, bad leadership, lack of originality and the likes are the causes of lack of authentic democratic practice and leadership in Africa and in Nigeria. Finally, this study concludes that the dividends of authentic democracy will be fully evident and rooted in Nigeria and Africa only when we embrace democracy in full.

Keywords: Political leadership, Democracy, Communalism
Ozo title institution in Igbo land in relation to politics in Nigeria: A comparative analysis
Authors: Nweke Innocent Ogbonna
Published: October 2020

Politics, they said is a dirty game. One tends to disagree with this assertion because man is a political being and everything man does is all about politics. It depends on the intention, and how each plays his or her own. Ozo title is one of the political institutions in Igbo land. It will be worthy to mention that the Ozo title meant in this paper is the primordial or original Ozo title in Igbo land and not the adulterated Ozo title today. It is one of the institutions that helps in governance, controls different sectors of the Igbo man’s life and equally checkmates the excesses in the land. This work tries to look at the politics in the Nigerian setting and that of the Igbo land as being championed by Ozo title men. It x-rays their day-to-day activities and compares them. The work equally will be able to evaluate the two. During the evaluation, it was discovered that politics is not dirty, it was also discovered that since the Ozo title men play this politics and play it very well, it now boils down on the makeup of the individual and the intentions of the people in it. It however suggests that the Nigerian leaders or politicians should look at the Ozo title institution and what it is for the Igbo man and borrow a leaf from them. The paper uses socio-cultural approach in the work. The paper finally warns that the Ozo title as used in this study is the primodial one and not the adulterated one. Thus, if the politicians in Nigerian today borrow from the Ozo title men in Igbo land, politics in Nigeria will be a better and an interesting one.

Key words: Ozo title, Igbo land, Leadership, Politics, Nigeria
Healthcare professionals’ opinions on psychological screening in follow-up care for childhood cancer survivors
Authors: Harju Erika , Hendriks Manya Jerina , Roser Katharina , Michel Gisela
Published: October 2020

INTRODUCTION
Implementation of screening for psychological distress in populations at risk, as recommended in existing guidelines, can be challenging on different levels: structural, organisational and personal (provider and patient). A specific group at risk for psychological distress, including anxiety and depression, is the growing population of childhood cancer survivors (CCS). In many countries, including Switzerland, the standardised assessment of psychological late effects during follow-up care is not yet established. The emotion thermometer, a short and validated assessment tool to screen for psychological distress, might facilitate implementation of psychological screening in Swiss CCS follow-up care.

AIMS OF THE STUDY
To inform implementation strategy and assess readiness of centres to integrate standardised psychological screening, we conducted a cross-sectional survey. We describe healthcare professionals’ opinions on (i) the current standard of psychological screening in follow-up care, (ii) their experience using the emotion thermometer, and (iii) perceived barriers and facilitators of possible implementation of psychological screening, including the emotion thermometer.

METHODS
We contacted 49 healthcare professionals involved in CCS follow-up care in all nine paediatric oncology clinics in Switzerland. The electronic survey included closed and open questions.

RESULTS
A majority of the healthcare professionals (17/24, 71%) stated that assessment of psychological distress is currently not standard in follow-up care. On the contrary, about half of them (11/24, 46%) think that psychological distress is adequately assessed in follow-up care. None of the participants had any previous experience with the emotion thermometer. After being informed about the emotion thermometer, nearly 80% (19/24) agree that it appears to be a good screening instrument and support the idea of regular application during follow-up care. Facilitators of implementation included the instrument’s brevity, its ability to visualise psychological topics and raising awareness of the need to think about the psychological side of follow-up care. Barriers included lack of time, the additional effort and the perception that instead an informal assessment would be sufficient. Concerns about using an artificial assessment, rather than a natural conversation, were also expressed.

CONCLUSIONS
There is overall agreement that screening for psychological late effects is not yet standard in follow-up care in Switzerland. It is important to mitigate perceived barriers and concerns of healthcare professionals to enable a successful implementation of psychological distress screening according to the established standards of care.
Inventory of the historical Dianthus sylvestris herbarium materials from Herbarium Croaticum and Herbarium Ivo and Marija Horvat
Authors: Terlević Ana , Rešetnik Ivana
Published: October 2020

In order to initiate a taxonomical revision of the Dianthus sylvestris group, an inventory of historical herbarium materials from ZA and ZAHO collections was conducted. Herbarium specimens of D. sylvestris group from these two herbaria were digitized and the data from the original herbarium labels were inserted in the Flora Croatica Database. A total of 344 herbarium sheets were digitized and six taxa (D. sylvestris Wulfen in Jacq. ssp. sylvestris, D. sylvestris ssp. tergestinus (Rchb.) Hayek, D. sylvestris ssp. longicaulis (Ten.) Greuter et Burdet, D. sylvestris ssp. nodosus (Tausch) Hayek, D. siculus C. Presl and D. arrosti C. Presl) were registered within studied collections. Inventory of herbarium sheets from ZA and ZAHO historical collections provided a significant insight into historical distributional data of D. sylvestris taxa related to the area of the Balkan Peninsula, which is a prerequisite for accurate taxonomic/ geographic sampling for further morphological and molecular analyses.
Harmonics of Double-fed Wind Power System with Grid-Tied Dual-PWM Converter
Authors: He Qiaoli
Published: October 2020

To fill the gaps of the double-fed wind power system, this paper conducts a study for the scarcity and integration of social resources. The LF harmonics on the DC and grid sides are surveyed based on the double Fourier transform algorithm, in conjunction with the power balance theory. A study model has also been built herein. The findings show that the calculated values of the HF harmonic components in the DFIG rotor current almost coincide with the simulation results, regardless of whether the wind velocity is 7 m/s or 19 m/s. When the three-phase voltage of the grid is unbalanced, the stator current contains the grid side basebands with LF harmonics of odd times, among which, the fundamental frequency of triple grid side baseband is the most distinct. It is thus clear that the simulation can capture relevant voltage and current data for the wind power system running in the balance and unbalanced states of grid voltages. it is therefore proved that the theoretical analysis is accurate and reliable.
MODEL PERMAINAN KREATIF UNTUK MEMOTIVASI SISWA DALAM PEMBELAJARAN BOLA VOLI PADA SISWA KELAS V SD
Authors: Albar Roni , Akbar Khairil , Susilawati Indria
Published: October 2020

Abstract: The general objective of this study is to motivate students in learning the bottom service volleyball game for grade V students of SD Negeri 09 Tanjung Lay. Specific purpose is to find out how much influence the creative game model has on students' motivation in volleyball games in grade V 09 Tanjug Lay Elementary School.This study uses classroom action research (Clasroom action research) using action cycles. In this action research, using the models described are: Planning (Action), Action (Action), Observation (Observation) and Reflection (Reflection).The findings of the study were: the results of student motivation increased, because in the first cycle the average value of students was 57.73 while in the second cycle the average value of students was 74.54 had reached the predetermined criteria.Based on the results of the study it can be concluded that through creative game models can motivate students in learning volleyball games in class V SD Negeri 09 Tanjung Lay. In this study, it can be suggested, the health teacher is expected to be able to plan and develop creativity and be more innovative in the learning process in an effort to improve student competencies, especially in choosing learning methods.Key Words: Creative Games, Volleyball Abstrak: Tujuan umum dari penelitian ini yaitu untuk memotivasi siswa dalam pembelajaran permainan bola voli  pada siswa kelas V SD Negeri 09 Tanjung Lay. Tujuan khusus adalah Untuk mengetahui seberapa besar pengaruh model permainan kreatif  terhadap motivasi siswa dalam permainan bola voli kelas V SD Negeri 09 Tanjug Lay. Penelitian ini menggunakan penelitian tindakan kelas (Clasroom action research) dengan menggunakan siklus tindakan. Pada penelitian tindakan ini, menggunakan model yang dijelaskan yaitu: Rencana (Planning), Tindakan (Action), Pengamatan (Observation) dan Refleksi (Reflection).Hasil temuan penelitian adalah : hasil motivasi siswa meningkat, karena pada siklus I nilai rata – rata siswa adalah 57.73 sedangkan pada siklus II nilai rata-rata siswa adalah 74.54 telah tercapai kriteria yang telah ditetapkan.Berdasarkan hasil penelitian dapat disimpulkan bahwa melalui model permainan kreatif dapat memotivasi siswa dalam pembelajaran  permainan bola voli pada siswa kelas V SD Negeri 09 Tanjung Lay.Dalam penelitian ini, dapat disarankan, guru penjaskes diharapkan dapat merencanakan dan mengembangkan kreativitas dan lebih inovatif pada proses pembelajaran dalam upaya meningkatkan kompetensi siswa terutama dalam memilih metode pembelajaran.Kata Kunci : Permainan Kreatif, Bola Voli
PENERAPAN PERMAINAN KASVO UNTUK MENINGKATKAN MOTIVASI PEMBELAJARAN BOLA VOLI PADA SISWA KELAS IV SDN 18 TANJUNG SARI
Authors: Mariana Mariana , Anggorowati Kurnia Dyah , Suyatmin Suyatmin
Published: October 2020

Abstrak: This study aims to improve students' motivation and learning gains in conducting learning tthe volley ball through the application of game KASVO in class IV SDN 18 KKLK Tanjung Sari Nanga Pinoh.Method in a study should be right or lead  to the research objectives and can be scientifically accounted results ar a expeted. The method used in this research is a class act.Based on the results of the research after the act of classed,the data showed that the acquisition of the percentage of learning motivation of fourtg grade students in class IV SDN 18 KKLK Tanjung Sari on the 1st cycle by 45%, success rate including less, are includedin the qualification success rate is quite good. The precentage of motivation for your teen to lear the fourth grade studentd in class IV SDN 18 KKLK Tanjung Sari on the second cycle of 85% is included in the qualification success rate”good” It can be conclude that the implementation of the game kasvo to improve the motivation to learn of students in learning volleyball on the students of class IV SDN 18 KKLK Tanjung Sari Nanga Pinoh said increasingKey words: Student Motivation, Game KASVO, Learning Volley Ball. Abstrak: Tujuan penelitian ini adalah untuk mengetahui peningkatan motivasi belajar siswa serta perolehan hasil belajar siswa dalam permainan bola voli dengan penerapan  permainan KASVO pada siswa kelas IV SDN 18 KKLK Tanjung Sari Nanga Pinoh. Metode dalam suatu penelitian harus tepat atau mengarah pada tujuan penelitian serta dapat dipertanggung jawabkan secara ilmiah sesuai dengan aturan yang berlaku, agar dalam penelitian tersebut dapat diperoleh hasil yang sesuai dengan yang diharapkan. Metode penelitian yang digunakan dalam penelitian ini adalah penelitian tindakan kelas. Berdasarkan hasil dari penelitian setelah dilakukan tindakan kelas, data menunjukanbahwaperolehanPresentase Motivasi belajar siswa kelas IV SDN 18 KKLK Tanjung Sari pada siklus I sebesar 45% tingkat kebehasilan termasuk kurang, termasuk dalam kualifikasi tingkat keberhasilan“ cukup baik” .Presentase Motivasi belajar siswa kelas IV SDN 18 KKLK Tanjung Sari pada siklus II sebesar 85% termasuk dalam kualifikasi tingkat keberhasilan “baik” Dengan demikaian dapat disimpulkan bahawa penerapan permainan KASVO untuk meningkatkan motivasi belajar siswa dalam pembelajaran bola voli pada siswa kelas iv SDN 18 KKLK Tanjung Sari Nanga Pinoh dikatakan berhasil.Kata Kunci: Motivasi Siswa, Permainan KASVO, Pembelajaran bola voli.
The Relationship Between Self Esteem Depression Anxiety and Stress Levels and Life Satisfaction in Licensed Swimmers Aged Between 14-25 Years
Authors: ŞENOL Sarp , TARI CÖMERT İtır , YÜKSELOĞLU Hülya , UĞRAŞ Seda , SALKIM Dilek , TUTKUN Erkut
Published: October 2020

Bu çalışmanın amacı, 14-25 yaş arası lisanslı yüzücülerde benlik saygısı, depresyon, anksiyete ve stres düzeyleri ile yaşam doyumu arasındaki ilişkiyi incelemektir. Çalışma, kartopu yöntemi ile yapılmıştır. Fenerbahçe Spor Kulübü, Galatasaray Spor Kulübü, Kınalıada Su Sporları Kulübü ve ENKA Spor Kulübü'nde faaliyetlerine devam eden 105 lisanslı yüzücünün rastgele örnekleme metodolojisinden elde edilen bilgileri gerçekleştirilmiştir. Çalışma Ocak 2017-Mart 2017 arasında yapılmıştır. Araştırma bulgular istatistiksel olarak T testinde tabi tutulmuştur. Elde edilen araştırma bulgularına göre cinsiyet ile yaşam doyumu arasında istatistiksel olarak anlamlı bir ilişki bulunmuştur. Yaş, benlik saygısı, depresyon, anksiyete ve stres düzeyi ile yaşam doyumu arasında istatistiksel olarak anlamlı bir ilişki vardı. Yüzme yılı ile benlik saygısı, depresyon, anksiyete düzeyi ve yaşam doyumu arasında istatistiksel olarak anlamlı bir ilişki olmasına rağmen, yüzme yılı ile stres düzeyi arasında istatistiksel olarak anlamlı bir ilişki yoktur. Sporculardan yüksek performans elde edilmek isteniyorsa erken yaşlardan itibaren sporcular kaygı ve stresi yönetme becerilerini geliştirmek için eğitilmelidir.