bluuebunny/crossref_metadata_2025_split huggingface dataset:
تأثير استراتيجية الصف المقلوب في تعلم مهارتي الارسال واستقباله بالكرة الطائرة لطلاب الثاني متوسط
Authors: حمزة سمير لغتة , هليل محمد حسن 
Published: February 2021

تكمن أهمية البحث في التنوع في عملية التعلم من خلال استخدام بدائل تعليمية تعطي للمتعلم دورا فعالا في عملية التعلم وتساعد على الحماس والتشويق للعملية التعليمية، وذلك من خلال تطبيق استراتيجية الصف المقلوب في تعلم مهارات الكرة الطائرة، حيث يشهد العالم تقدماً واسعاً في مجال تكنولوجيا المعلومات شملت جميع مجالات الحياة ويظهر ذلك جلياً في التطورات الهائلة والسريعة في المعرفة العلمية التي تمثلت بالاكتشافات الجديدة والمتلاحقة في منظومة عالمية اتسمت بالتغييرات السريعة من اجل اختصار الجهد والوقت للوصول الى الاهداف ، وفي ظل هذه التغييرات الحادثة كان لابد من اعادة النظر في الاستراتيجيات والطرائق التعليمية التي تتناسب مع هذه التطورات التكنولوجية من اجل توفير بيئة تعليمية تلبي رغبات واحتياجات المتعلمين، واجري البحث على عينة من طلاب متوسطة صدى المعرفة للطلبة المتفوقين، حيث تم تقسيمهم الى مجموعتين تجريبية وضابطة لكل مجموعة (10) طلاب، وتم تنفيذ التجربة الرئيسة بتاريخ 24/2/2019 ولغاية 21/4/2019، بواقع وحدتين تعليميتين في الاسبوع ولمدة ثمانية اسابيع وبمجموع (16) وحدة تعليمية، ثم تم اجراء الاختبارات البعدية لمجموعتي البحث التجريبية والضابطة بتاريخ (21/4/2019) مع مراعاة الظروف الزمانية والمكانية وتنفيذ الاجراءات المتبعة نفسها وفق الاختبار القبلي وبمساعدة فريق العمل المساعد نفسه، واخذت النتائج البحث وعولجت البيانات احصائيا وعرضت ونوقشت بأسلوب علمي، وتوصل الباحثان الى بعض الاستنتاجات أهمها: ان استراتيجية الصف المقلوب كان لها الأفضلية والأثر الإيجابي في تعلم مهارتي الارسال واستقباله بالكرة الطائرة. وان مقاطع الفيديو المعدة ضمن استراتيجية الصف المقلوب وما تضمنته من طريقة العرض البطي والاعتيادي والتعليق وإضافة الرموز والعلامات التوضيحية والموسيقى المناسبة كان لها الأثر الواضح في اثارة المتعة والتشويق لدى الطلاب مما انعكس على مستوى تعلمهم.
الكلمات المفتاحية: الصف المقلوب، التعلم، الكرة الطائرة.
A Multiwavelength Look at the GJ 9827 System: No Evidence of Extended Atmospheres in GJ 9827b and d from HST and CARMENES Data
Authors: Carleo Ilaria , Youngblood Allison , Redfield Seth , Barris Nuria Casasayas , Ayres Thomas R. , Vannier Hunter , Fossati Luca , Palle Enric , Livingston John H. , Lanza Antonino F. , Niraula Prajwal , Alvarado-Gómez Julián D. , Chen Guo , Gandolfi Davide , Guenther Eike W. , Linsky Jeffrey L. , Nagel Evangelos , Narita Norio , Nortmann Lisa , Shkolnik Evgenya L. , Stangret Monika 
Published: February 2021

Abstract
GJ 9827 is a bright star hosting a planetary system with three transiting planets. As a multiplanet system with planets that sprawl within the boundaries of the radius gap between terrestrial and gaseous planets, GJ 9827 is an optimal target to study the evolution of the atmospheres of close-in planets with a common evolutionary history and their dependence from stellar irradiation. Here we report on the Hubble Space Telescope (HST) and CARMENES transit observations of GJ 9827 planets b and d. We performed a stellar and ISM characterization from the ultraviolet HST spectra, obtaining fluxes for Lyα and Mg ii of F(Lyα) = (5.42

) × 10−13 erg cm−2 s−1 and F(Mgii) = (5.64 ± 0.24) × 10−14 erg cm−2 s−1. We also investigated a possible absorption signature in Lyα in the atmosphere of GJ 9827b during a transit event from HST spectra, as well as Hα and He i signature for the atmosphere of GJ 9827b and d from CARMENES spectra. We found no evidence of an extended atmosphere in either of the planets. This result is also supported by our analytical estimations of mass loss based on the measured radiation fields for all three planets of this system, which led to a mass-loss rate of 0.4, 0.3, and 0.1 planetary masses per Gyr for GJ 9827b, c, and d, respectively. These values indicate that the planets could have lost their volatiles quickly in their evolution and probably do not retain an atmosphere at the current stage.
High-resolution Mid-infrared Spectroscopy of GV Tau N: Surface Accretion and Detection of NH3 in a Young Protoplanetary Disk
Authors: Najita Joan R. , Carr John S. , Brittain Sean D. , Lacy John H. , Richter Matthew J. , Doppmann Greg W. 
Published: February 2021

Abstract
Physical processes that redistribute or remove angular momentum from protoplanetary disks can drive mass accretion onto the star and affect the outcome of planet formation. Despite ubiquitous evidence that protoplanetary disks are engaged in accretion, the process(es) responsible remain unclear. Here we present evidence for redshifted molecular absorption in the spectrum of a Class I source that indicates rapid inflow at the disk surface. High-resolution mid-infrared spectroscopy of GV Tau N reveals a rich absorption spectrum of individual lines of C2H2, HCN, NH3, and H2O. From the properties of the molecular absorption, we can infer that it carries a significant accretion rate

∼ 10−8–10−7
M
⊙ yr−1, comparable to the stellar accretion rates of active T Tauri stars. Thus, we may be observing disk accretion in action. The results may provide observational evidence for supersonic “surface accretion flows,” which have been found in MHD simulations of magnetized disks. The observed spectra also represent the first detection of NH3 in the planet formation region of a protoplanetary disk. With NH3 only comparable in abundance to HCN, it cannot be a major missing reservoir of nitrogen. If, as expected, the dominant nitrogen reservoir in inner disks is instead N2, its high volatility would make it difficult to incorporate into forming planets, which may help to explain the low nitrogen content of the bulk Earth.
The CatWISE2020 Catalog
Authors: Marocco Federico , Eisenhardt Peter R. M. , Fowler John W. , Kirkpatrick J. Davy , Meisner Aaron M. , Schlafly Edward F. , Stanford S. A. , Garcia Nelson , Caselden Dan , Cushing Michael C. , Cutri Roc M. , Faherty Jacqueline K. , Gelino Christopher R. , Gonzalez Anthony H. , Jarrett Thomas H. , Koontz Renata , Mainzer Amanda , Marchese Elijah J. , Mobasher Bahram , Schlegel David J. , Stern Daniel , Teplitz Harry I. , Wright Edward L. 
Published: February 2021

Abstract
The CatWISE2020 Catalog consists of 1,890,715,640 sources over the entire sky selected from Wide-field Infrared Survey Explorer (WISE) and NEOWISE survey data at 3.4 and 4.6 μm (W1 and W2) collected from 2010 January 7 to 2018 December 13. This data set adds two years to that used for the CatWISE Preliminary Catalog, bringing the total to six times as many exposures spanning over 16 times as large a time baseline as the AllWISE catalog. The other major change from the CatWISE Preliminary Catalog is that the detection list for the CatWISE2020 Catalog was generated using crowdsource from Schlafly et al., while the CatWISE Preliminary Catalog used the detection software used for AllWISE. These two factors result in roughly twice as many sources in the CatWISE2020 Catalog. The scatter with respect to Spitzer photometry at faint magnitudes in the COSMOS field, which is out of the Galactic Plane and at low ecliptic latitude (corresponding to lower WISE coverage depth) is similar to that for the CatWISE Preliminary Catalog. The 90% completeness depth for the CatWISE2020 Catalog is at W1 = 17.7 mag and W2 = 17.5 mag, 1.7 mag deeper than in the CatWISE Preliminary Catalog. In comparison to Gaia, CatWISE2020 motions are accurate at the 20 mas yr−1 level for W1∼15 mag sources and at the ∼100 mas yr−1 level for W1∼17 mag sources. This level of accuracy represents a 12× improvement over AllWISE. The CatWISE catalogs are available in the WISE/NEOWISE Enhanced and Contributed Products area of the NASA/IPAC Infrared Science Archive.
Determination of Solar Wind Angular Momentum and Alfvén Radius from Parker Solar Probe Observations
Authors: Liu Ying D. , Chen Chong , Stevens Michael L. , Liu Mingzhe 
Published: February 2021

Abstract
As fundamental parameters of the Sun, the Alfvén radius and angular momentum loss determine how the solar wind changes from sub-Alfvénic to super-Alfvénic and how the Sun spins down. We present an approach to determining the solar wind angular momentum flux based on observations from Parker Solar Probe (PSP). A flux of about 0.15 × 1030 dyn cm sr−1 near the ecliptic plane and 0.7:1 partition of that flux between the particles and magnetic field are obtained by averaging data from the first four encounters within 0.3 au from the Sun. The angular momentum flux and its particle component decrease with the solar wind speed, while the flux in the field is remarkably constant. A speed dependence in the Alfvén radius is also observed, which suggests a “rugged” Alfvén surface around the Sun. Substantial diving below the Alfvén surface seems plausible only for relatively slow solar wind given the orbital design of PSP. Uncertainties are evaluated based on the acceleration profiles of the same solar wind streams observed at PSP and a radially aligned spacecraft near 1 au. We illustrate that the “angular momentum paradox” raised by Réville et al. can be removed by taking into account the contribution of the alpha particles. The large proton transverse velocity observed by PSP is perhaps inherent in the solar wind acceleration process, where an opposite transverse velocity is produced for the alphas with the angular momentum conserved. Preliminary analysis of some recovered alpha parameters tends to agree with the results.
NEOWISE Observed CO and CO2 Production Rates of 46P/Wirtanen During the 2018–2019 Apparition*
Authors: Bauer James M. , Gicquel Adeline , Kramer Emily , Meech Karen J. 
Published: February 2021

Abstract
We present measurements of comet 46P/Wirtanen obtained by the NEOWISE spacecraft in 2017 through 2019. We detected signal in excess of the dust in the 4.6 μm channel attributable to the presence of CO, or more likely, CO2 emission. The excess, when the comet was outbound at a heliocentric distance of 1.9 au, was consistent with a CO2 production rate of 1.3(±0.07) × 1026 molecules per second, which is equivalent to an active area on the order of a percent of the comet nucleus’ total surface.
Characterizing the Manx Candidate A/2018 V3
Authors: Piro Caroline , Meech Karen J. , Bufanda Erica , Kleyna Jan T. , Keane Jacqueline V. , Hainaut Olivier , Micheli Marco , Bauer James , Denneau Larry , Weryk Robert , Bhatt Bhuwan C. , Sahu Devendra K. , Wainscoat Richard 
Published: February 2021

Abstract
Manx objects approach the inner solar system on long-period comet (LPC) orbits with the consequent high inbound velocities, but unlike comets, Manxes display very little to no activity even near perihelion. This suggests that they may have formed in circumstances different from typical LPCs; moreover, this lack of significant activity also renders them difficult to detect at large distances. Thus, analyzing their physical properties can help constrain models of solar system formation as well as sharpen detection methods for those classified as NEOs. Here, we focus on the Manx candidate A/2018 V3 as part of a larger effort to characterize Manxes as a whole. This particular object was observed to be inactive even at its perihelion at q = 1.34 au in 2019 September. Its spectral reflectivity is consistent with typical organic-rich comet surfaces with colors of

g
′
−
r
′
=
0.67
±
0.02

,

r
′
−
i
′
=
0.26
±
0.02

, and

r
′
−
z
′
=
0.45
±
0.02

, corresponding to a spectral reflectivity slope of 10.6 ± 0.9%/100 nm. A least-squares fit of our constructed light curve to the observational data yields an average nucleus radius of ≈2 km assuming an albedo of 0.04. This is consistent with the value measured from NEOWISE. A surface brightness analysis for data taken 2020 July 13 indicated possible low activity (≲0.68 g s−1), but not enough to lift optically significant amounts of dust. Finally, we discuss Manxes as a constraint on solar system dynamical models as well as their implications for planetary defense.
Uncertainties on Asteroid Albedos Determined by Thermal Modeling
Authors: Masiero Joseph R. , Wright E. L. , Mainzer A. K. 
Published: February 2021

Abstract
We present an analysis of the accuracy of geometric albedos determined for asteroids through the modeling of observed thermal infrared radiation. We show that albedo uncertainty is dominated by the uncertainty on the measured H

V
absolute magnitude, and that any analysis using albedos in a statistical application will also be dominated by this source of uncertainty. For all but the small fraction of asteroids with a large amount of characterization data, improved knowledge of the H

V
magnitude will be fundamentally limited by incomplete phase-curve coverage, incomplete light-curve knowledge, and the necessary conversion from the observed band to the V band. Switching the absolute magnitude standard to a different band such a

r
′

would mitigate the uncertainty due to band conversion for many surveys, but this only represents a small component of the total uncertainty. Therefore, techniques making use of these albedos must ensure that their uncertainties are properly accounted for.
Efficient Immune Cell Genome Engineering with Enhanced CRISPR Editing Tools
Authors: Chan Waipan , Gottschalk Rachel A , Yao Yikun , Pomerantz Joel L , Germain Ronald N 
Published: February 2021

Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)–based methods have revolutionized genome engineering and the study of gene-phenotype relationships. However, modifying cells of the innate immune system, especially macrophages, has been challenging because of cell pathology and low targeting efficiency resulting from nucleic acid activation of intracellular sensors. Likewise, lymphocytes of the adaptive immune system are difficult to modify using CRISPR-enhanced homology-directed repair because of inefficient or toxic delivery of donor templates using transient transfection methods. To overcome these challenges and limitations, we modified existing tools and developed three alternative methods for CRISPR-based genome editing using a hit-and-run transient expression strategy, together with a convenient system for promoting gene expression using CRISPRa. Overall, our CRISPR tools and strategies designed to tackle both murine and human immune cell genome engineering provide efficient alternatives to existing methods and have wide application not only in terms of hematopoietic cells but also other mammalian cell types of interest.
Antibiotic resistance patterns of salmonella typhi isolated from ready-to-eat vegetable salads hawked in Kano Metropolis
Authors: Mohammed B. , Muhammad A.U. 
Published: February 2021

A total of 200 samples of Ready – to – Eat (RTE) vegetable salads were aseptically purchased randomly from hawkers in eight Local Governments of Kano State, Nigeria. The aerobic mesophilic bacterial count was conducted according to standard techniques. Samples were further screened for S. Typhi and C. jejuni using standard procedures. Isolates of the two bacterial species were subjected to antibiotic sensitivity testing using Kirby Buer disk diffusion technique. The total aerobic bacteria count ranged from 1.200x105 to 1.70x105 cfu/g. A total of 36 bacterial isolates from the RTE vegetables were identified as C. jejuni (18%) and 97 (48.5%) as S. Typhi. Ninety percent (90%) of the isolates were found to be resistant to the assayed antibiotics. C. jejuni was highly sensitive (98.4%) to gentamicin. TEM genes were detected in 40% of the C. jejuni isolates while 60% were detected in S. Typhi isolates. RTE vegetable salads hawked in study areas are contaminated with C. jejuni and S. Typhi and the isolates were resistant to most of the antibiotics tested. It is recommended that hazard analysis and critical control point of ready to eat food should be observed.
Relationship between body adiposity index and serum glycemic level among post menupausal women in Muritala Muhammad Specialist Hospital Kano, Nigeria
Authors: Kayode K.F. , Abdullahi Y.A. , Badamasi I.M. 
Published: February 2021

Body adiposity index (BAI) is documented to exhibit significant relationship with the component of metabolic syndromes (MetS) including serum glucose. The relationship between BAI and serum glucose among postmenopausal women has not been well studied. This study was aimed at determining the relationship between BAI and serum glycemic level among postmenopausal women. The study design was observational crosssectional. Fasting serum glucose was obtained via superficial vein venipuncture after at least eight hours of meal and was analysed following standard biochemical procedure. Standard techniques for anthropometric measurement were used in obtaining the standard parameters. Chi-square was used to determine the relationship between body mass index (BMI) and clinically accepted categorical subdivision of fasting blood sugar (FBG). A total of 156 postmenopausal women with mean age of 62.70 ± 12.84 years, height (1.58 ± 0.07) m, weight (67.30 ± 17.68) kg, hip circumference (99.94 ± 12.75) cm, waist circumference (86.56 ± 14.25) cm, BAI (32.61 ± 6.78), BMI (27.05 ± 6.90) kh/m2 and fasting blood sugar (FBS) (5.21 ± 2.78mmol/L) were assessed in the here was significant positive correlation between BAI and BMI (r = 0.877, P = 6.97x10-51) and not between BAI and FBG (r = 0.026, P = 0.748). In conclusion BAI was not significantly associated with serum glycemic level among post-menopausal women.
Towards a National Framework for Digital Preservation in Nigeria: Technologies and Best Practices
Authors: Oguche David , Aliyu Asabe 
Published: February 2021

The need for preserving digital resources (acquired or generated) by institutions in Nigeria becomes imperative in the wake of adoption of Information and Communication Technologies (ICT) by these institutions. The paper advocates for a national framework for preserving digital resources for long-term or future use and to avoid the risk of losing national memory in this digital age. Technology emulation, migration and encapsulation are some of the digital preservation strategies discussed in the paper. The paper also identified two key national institutions that can drive the digital preservation initiative in Nigeria.
Keywords: Archive, Preservation, Digital materials, Technology Obsolence
Awareness of Information and Communication Technology-Based Information Resources in Library User Education Programmes in Colleges of Education in Southern Nigeria
Authors: Okonoko Vera Ngozi , Eruvwe Ufuoma 
Published: February 2021

The study investigated awareness of information and communication technology-based information resources in library user education programmes in South-South Nigeria. Three research questions and one hypothesis guided the study. Descriptive survey research design was adopted for the study. The population of the study comprised of 1022 respondents which consist of 62 staff and 960 library users. The instrument for data collection was questionnaire of a four-point rating scale and observation checklist. Tools used for data analysis of research questions were frequency, percentage, mean and standard deviation; t-test was used to test the null hypothesis at selected probability of 0.05 level significance. The findings revealed that more than half of the listed ICT-based resources were available in the six colleges of education libraries under study. The study also shows that the respondents had high awareness on these items. It was deduced from the findings that the method used to a high extent for awareness of ICT-based resources for user education programmes in colleges of education libraries was conferences. The study recommended among others, that, colleges of education authorities should embark on capacity building programmes in terms of training and re-training of librarians on ICT awareness.
Keywords: Awareness, Information Resources, User education, ICT
Western Education versus Indigenous Knowledge of the Tarok in Plateau State, Nigeria
Authors: Shehu Allahde 
Published: February 2021

This paper advocates the need for the preservation and conservation of Indigenous Knowledge of the Tarok in Plateau State, Nigeria. The paper started by discussing western education and the indigenous knowledge of the Tarok people and the possible threat of indigenous knowledge extinction due to lack of written records and problems associated with preservation and conservation of the knowledge. The paper also looked at the brief history of Tarok People, the philosophical basis of the Tarok indigenous knowledge/education, the differences and similarities between Tarok indigenous knowledge and western education, and the aspect of the Tarok indigenous knowledge. Finally, the paper concluded that the Tarok indigenous knowledge was more practical than the western education and that the indigenous type of education had a bearing to the traditions, norms and culture of the people. The paper also recommended among others, the establishment of Tarok indigenous knowledge resource centres (museum) and written record on Tarok indigenous knowledge to avoid the threat of extinction.
Keywords: Western Education, Indigenous Knowledge, Preservation, Tarok
EFEKTIVITAS BIOFUNGISIDA Trichoderma koningii TERHADAP PENCEGAHAN PENYAKIT JAMUR AKAR PUTIH DI PEMBIBITAN BATANG BAWAH TANAMAN KARET (Hevea brasiliensis)
Authors: Tarigan Gema , Wahyuni Mardiana , . Guntoro 
Published: February 2021

One of the main obstacles in rubber cultivation is the white root fungus (JAP) attack which caused by Rigidophorus ligonosus. This pathogen infects rubber plants from the nursery until the mature plants. Efforts to control the disease have been carried out by chemical, technical culture and use of biological agencies. This research was conducted at the STIP-AP Medan in January 2017 to June 2017, this study used a non-factorial Randomized Block Design (RBD) with four replications and four treatments. Using Trichoderma koningii with somes doses were 20 grams, 30 grams, and 40 grams/seedling. The results of this study indicate that the biofungicide application of Trichoderma koningii 30 g/seedling produces the greatest inhibition of the rubber plants seedling nursery against the growth of pathogens Rigidoporus lignosus.
Distribution and antifungal susceptibility of candida species isolated from blood culture
Authors: Selim Gorgun  , Melek Bilgin  , Suleyman Sirri Kilic  , Admin  
Published: February 2021

Abstract
Objective: The aim of this study is to determine the distribution of samples exhibiting Candida growth among the blood cultures, and the antifungal susceptibility.
Methods: The retrospective study was conducted in Samsun Training and Research Hospital, Samsun, Turkey from January to December, 2018 and comprised immunosuppressed patients with sepsis. Ethical approval was obtained and consent was taken from all patients. Yeast growths were typed by means of colony morphology, germ tube formation and the VITEK 2 system. Their susceptibilities tests were determined using the same automatized system. Resistance strains were also tested using the dilution method.
Results: Of the 50 patients, 19(38%) were females and 31(62%) were males. The overall mean age was 60.84 ± 22.05 years. 31 (62%) of the samples were received from intensive care units, 14 (28%) from the palliative care unit, and five from other inpatients. In our study, most common among our isolates was C. albicans, and C. parapsiosis was most common among non-albicans species. Resistance to antifungals was observed in 28% of Candida isolates. Of the total isolates, %10 were found to be naturally resistant to fluconazole, 8% to voriconazole, 4% to flucytosine, and amphotericin B. The high resistance rate for fluconazole in Candida species is noteworthy. The findings obtained through both the dilution method and the automatized system were consistent.
Continuou....