bluuebunny/crossref_metadata_2025 huggingface dataset:
Childhood socio-economic conditions and risk of cardiovascular disease: results from a pooled sample of 14 011 adults from India
Authors: Mallinson Poppy Alice Carson , Lieber Judith , Bhogadi Santhi , Kinra Sanjay
Published: June 2020

Background

South Asians are at an increased risk of premature cardiovascular disease, but the reasons for this are unclear. Poor socio-economic conditions in childhood are associated with an increased risk of cardiovascular disease in many high-income countries and may be particularly relevant to South Asia, where socio-economic deprivation is more prevalent and severe. However, evidence from South Asia is limited.

Methods

We pooled data from two large population-based studies in India to provide a geographically representative and adequately powered sample of Indian adults. We used multilevel linear regression models to assess associations between standard of living index (SLI) in childhood (measured by recalled household assets at age 10–12 years) and major cardiovascular risk factors including adiposity, blood pressure, and fasting blood lipids, glucose and insulin.

Results

Data on 14 011 adults (median age 39 years, 56% men) were analysed. SLI in childhood was inversely associated with systolic and diastolic blood pressure, independent of socio-economic conditions in adulthood, with beta coefficients (95% CIs) of −0.70 mmHg (−1.17 to −0.23) and −0.56 mmHg (−0.91 to −0.22), respectively, per SD increase in SLI in childhood. There was no strong evidence for an association between SLI in childhood and other risk factors of cardiovascular disease.

Conclusions

Poor socio-economic conditions in childhood may contribute to the increased risk of premature cardiovascular disease among South Asians by raising their blood pressure. Elucidating the mechanisms and improving socio-economic conditions for children in South Asia could provide major reductions in the burden of cardiovascular disease.
Diagnosis and management of acute ischaemic stroke
Authors: Hurford Robert , Sekhar Alakendu , Hughes Tom A T , Muir Keith W
Published: June 2020

Acute ischaemic stroke is a major public health priority and will become increasingly relevant to neurologists of the future. The cornerstone of effective stroke care continues to be timely reperfusion treatment. This requires early recognition of symptoms by the public and first responders, triage to an appropriate stroke centre and efficient assessment and investigation by the attending stroke team. The aim of treatment is to achieve recanalisation and reperfusion of the ischaemic penumbra with intravenous thrombolysis and/or endovascular thrombectomy in appropriately selected patients. All patients should be admitted directly to an acute stroke unit for close monitoring for early neurological deterioration and prevention of secondary complications. Prompt investigation of the mechanism of stroke allows patients to start appropriate secondary preventative treatment. Future objectives include improving accessibility to endovascular thrombectomy, using advanced imaging to extend therapeutic windows and developing neuroprotective agents to prevent secondary neuronal damage.
Kerr-MOG black holes with stationary scalar clouds
Authors: Qiao Xiongying , Wang Mengjie , Pan Qiyuan , Jing Jiliang
Published: June 2020

We establish the existence of stationary clouds of massive test scalar fields around Kerr-MOG black holes. By solving the Klein–Gordon equation numerically, we present the existence lines of the clouds in the parameter space of the Kerr-MOG black holes, and investigate the effect of the MOG parameter on the rich structure of scalar clouds. We observe that the MOG parameter leads to the split of the existence lines for the scalar clouds, and the larger MOG parameter makes it possible for the clouds to exist in the case of the lower background angular velocity. Numerical results are compared with the analytical formula obtained by an asymptotic matching method, and we find that both results are consistent with each other. In particular, it is shown that the larger MOG parameter, the better agreement between analytical and numerical results. This implies that the matching method is a powerful analytical tool to investigate the scalar clouds existing in the Kerr-MOG black holes. Moreover, we obtain the location of the existence lines and show that the clouds are concentrated at the larger radial position for the Kerr-MOG black holes when compared to the Kerr black holes.
Covering Small Independent Sets and Separators with Applications to Parameterized Algorithms
Authors: Lokshtanov Daniel , Panolan Fahad , Saurabh Saket , Sharma Roohani , Zehavi Meirav
Published: June 2020

We present two new combinatorial tools for the design of parameterized algorithms. The first is a simple linear time randomized algorithm that given as input a
d
-degenerate graph
G
and an integer
k
, outputs an independent set
Y
, such that for every independent set
X
in
G
of size at most
k
, the probability that
X
is a subset of
Y
is at least ((
(d+1)k
k
) .
k
(d+1))
-1
. The second is a new (deterministic) polynomial time graph sparsification procedure that given a graph
G
, a set
T
= {s_1, t_1} , {s_2, t_2}, …. , {s_ℓ , t_ℓ} of terminal pairs, and an integer
k
, returns an induced subgraph
G*
of
G
that maintains
all
the inclusion minimal multicuts of
G
of size at most
k
and does not contain any (
k
+2)-vertex connected set of size 2
O(k)
. In particular,
G*
excludes a clique of size 2
O(k)
as a topological minor. Put together, our new tools yield new randomized fixed parameter tractable (FPT) algorithms for S
TABLE
s-t
S
EPARATOR
, S
TABLE
O
DD
C
YCLE
T
RANSVERSAL
, and S
TABLE
M
ULTICUT
on general graphs, and for S
TABLE
D
IRECTED
F
EEDBACK
V
ERTEX
S
ET
on
d
-degenerate graphs, resolving two problems left open by Marx et al. [
ACM Transactions on Algorithms,
2013{. All of our algorithms can be derandomized at the cost of a small overhead in the running time.
The Complexity of Cake Cutting with Unequal Shares
Authors: Cseh Ágnes , Fleiner Tamás
Published: June 2020

An unceasing problem of our prevailing society is the fair division of goods. The problem of proportional cake cutting focuses on dividing a heterogeneous and divisible resource, the cake, among
n
players who value pieces according to their own measure function. The goal is to assign each player a not necessarily connected part of the cake that the player evaluates at least as much as her proportional share.

In this article, we investigate the problem of proportional division with unequal shares, where each player is entitled to receive a predetermined portion of the cake. Our main contribution is threefold. First we present a protocol for integer demands, which delivers a proportional solution in fewer queries than all known protocols. By giving a matching lower bound, we then show that our protocol is asymptotically the fastest possible. Finally, we turn to irrational demands and solve the proportional cake cutting problem by reducing it to the same problem with integer demands only. All results remain valid in a highly general cake cutting model, which can be of independent interest.
Time- and Space-optimal Algorithm for the Many-visits TSP
Authors: Berger André , Kozma László , Mnich Matthias , Vincze Roland
Published: June 2020

The many-visits traveling salesperson problem (MV-TSP) asks for an optimal tour of
n
cities that visits each city
c
a prescribed number

k
c

of times. Travel costs may be asymmetric, and visiting a city twice in a row may incur a non-zero cost. The MV-TSP problem finds applications in scheduling, geometric approximation, and Hamiltonicity of certain graph families.

The fastest known algorithm for MV-TSP is due to Cosmadakis and Papadimitriou (SICOMP, 1984). It runs in time n
O(n)
+ O(n
3
log ∑
c
k
c
) and requires n
ᶿ(n)
space. An interesting feature of the Cosmadakis-Papadimitriou algorithm is its
logarithmic
dependence on the total length ∑

c
k
c

of the tour, allowing the algorithm to handle instances with very long tours. The
superexponential
dependence on the number of cities in both the time and space complexity, however, renders the algorithm impractical for all but the narrowest range of this parameter.

In this article, we improve upon the Cosmadakis-Papadimitriou algorithm, giving an MV-TSP algorithm that runs in time 2
O(n)
, i.e.,
single-exponential
in the number of cities, using
polynomial
space. The space requirement of our algorithm is (essentially) the size of the output, and assuming the Exponential-Time Hypothesis (ETH), the problem cannot be solved in time 2
o(n)
. Our algorithm is deterministic, and arguably both simpler and easier to analyze than the original approach of Cosmadakis and Papadimitriou. It involves an optimization over directed spanning trees and a recursive, centroid-based decomposition of trees.
An Improved Isomorphism Test for Bounded-tree-width Graphs
Authors: Grohe Martin , Neuen Daniel , Schweitzer Pascal , Wiebking Daniel
Published: June 2020

We give a new FPT algorithm testing isomorphism of
n
-vertex graphs of tree-width
k
in time
2
kpolylog(k)

n
3

, improving the FPT algorithm due to Lokshtanov, Pilipczuk, Pilipczuk, and Saurabh (FOCS 2014), which runs in time 2
O(k5 log k)
n
5
. Based on an improved version of the isomorphism-invariant graph decomposition technique introduced by Lokshtanov et al., we prove restrictions on the structure of the automorphism groups of graphs of tree-width
k
. Our algorithm then makes heavy use of the group theoretic techniques introduced by Luks (JCSS 1982) in his isomorphism test for bounded degree graphs and Babai (STOC 2016) in his quasipolynomial isomorphism test. In fact, we even use Babai’s algorithm as a black box in one place.

We also give a second algorithm that, at the price of a slightly worse running time 2
O(k2 log k)
n
3
, avoids the use of Babai’s algorithm and, more importantly, has the additional benefit that it can also be used as a canonization algorithm.
Structure Learning of H-Colorings
Authors: Blanca Antonio , Chen Zongchen , Štefankoviè Daniel , Vigoda Eric
Published: June 2020

We study the following structure learning problem forH-colorings. For a fixed (and known) constraint graphHwithqcolors, given access to uniformly randomH-colorings of an unknown graphG=(V,E), how many samples are required to learn the edges of G? We give a characterization of the constraint graphs Hfor which the problem is identifiable for every Gand show that there are identifiable constraint graphs for which one cannot hope to learn every graph Gefficiently. We provide refined results for the case of proper vertexq-colorings of graphs of maximum degree d. In particular, we prove that in the tree uniqueness region (i.e., whenq≤ d), the problem is identifiable and we can learnGin poly(d,q)× O(n2logn) time. In the tree non-uniqueness region (i.e., when q≤ d), we show that the problem is not identifiable and thusGcannot be learned. Moreover, whenq ≤ d- √d + Θ (1), we establish that even learning an equivalent graph (any graph with the same set ofH-colorings) is computationally hard—sample complexity is exponential innin the worst case. We further explore the connection between the efficiency/hardness of the structure learning problem and the uniqueness/non-uniqueness phase transition for generalH-colorings and prove that under a well-known uniqueness condition in statistical physics, we can learnGin poly(d,q)× O(n2logn) time.
Random Walks on Small World Networks
Authors: Dyer Martin E. , Galanis Andreas , Goldberg Leslie Ann , Jerrum Mark , Vigoda Eric
Published: June 2020

We study the mixing time of random walks on small-world networks modelled as follows: starting with the 2-dimensional periodic grid, each pair of vertices {u,v} with distance d> 1 is added as a “long-range” edge with probability proportional to d
-r
, where r≥ 0 is a parameter of the model. Kleinberg [33{ studied a close variant of this network model and proved that the (decentralised) routing time is O((log
n
)
2
) when
r
=2 and n
Ω (1)
when r≠ 2. Here, we prove that the random walk also undergoes a phase transition at
r=2
, but in this case, the phase transition is of a different form. We establish that the mixing time is ϴ (log n) for r< 2, O((log
n
)
4
) for
r
=2, and
n
Ω (1)
for r> 2.
A PTAS for Euclidean TSP with Hyperplane Neighborhoods
Authors: Antoniadis Antonios , Fleszar Krzysztof , Hoeksma Ruben , Schewior Kevin
Published: June 2020

In the Traveling Salesperson Problem with Neighborhoods (TSPN), we are given a collection of geometric regions in some space. The goal is to output a tour of minimum length that visits at least one point in each region. Even in the Euclidean plane, TSPN is known to be APX-hard [27{, which gives rise to studying more tractable special cases of the problem. In this article, we focus on the fundamental special case of regions that are hyperplanes in the
d
-dimensional Euclidean space. This case contrasts the much-better understood case of so-called fat regions [20, 40{.

While for
d
= 2, an exact algorithm with a running time of O(n
5
) is known [34{, settling the exact approximability of the problem for
d
= 3 has been repeatedly posed as an open question [29, 30, 40, 47{. To date, only an approximation algorithm with guarantee exponential in
d
is known [30{, and NP-hardness remains open.

For arbitrary fixed
d
, we develop a Polynomial Time Approximation Scheme (PTAS) that works for both the tour and path version of the problem. Our algorithm is based on approximating the convex hull of an optimal tour by a convex polytope of bounded complexity. After enumerating a number of structural properties of these polytopes, a linear program finds one of them that minimizes the length of the tour. As the approximation guarantee approaches 1, our scheme adjusts the complexity of the considered polytopes accordingly.

In the analysis of our approximation scheme, we show that our search space includes a sufficiently good approximation of the optimum. To do so, we develop a novel and general sparsification technique that transforms an arbitrary convex polytope into one with a constant number of vertices, and, subsequently, into one of bounded complexity in the above sense. We show that this transformation does not increase the tour length by too much, while the transformed tour visits any hyperplane that it visited before the transformation.
Clustering in Hypergraphs to Minimize Average Edge Service Time
Authors: Rottenstreich Ori , Kaplan Haim , Hassidim Avinatan
Published: June 2020

We study the problem of clustering the vertices of a weighted hypergraph such that on average the vertices of each edge can be covered by a small number of clusters. This problem has many applications, such as for designing medical tests, clustering files on disk servers, and placing network services on servers. The edges of the hypergraph model groups of items that are likely to be needed together, and the optimization criteria that we use can be interpreted as the average delay (or cost) to serve the items of a typical edge. We describe and analyze algorithms for this problem for the case in which the clusters have to be disjoint and for the case where clusters can overlap. The analysis is often subtle and reveals interesting structure and invariants that one can utilize.
Privado
Authors: Boshrooyeh Sanaz Taheri , Küpçü Alptekin , Özkasap Öznur
Published: June 2020

Online Social Networks (OSNs) offer free storage and social networking services through which users can communicate personal information with one another. The personal information of the users collected by the OSN provider comes with privacy problems when being monetized for advertising purposes. To protect user privacy, existing studies propose utilizing data encryption that immediately prevents OSNs from monetizing users data and hence leaves secure OSNs with no convincing commercial model. To address this problem, we propose Privado as a privacy-preserving group-based advertising mechanism to be integrated into secure OSNs to re-empower monetizing ability. Privado is run by
N
servers, each provided by an independent provider. User privacy is protected against an active malicious adversary controlling
N
− 1 providers, all the advertisers, and a large fraction of the users. We base our design on the group-based advertising notion to protect user privacy, which is not possible in the personalized variant. Our design also delivers advertising transparency; the procedure of identifying target customers is operated solely by the OSN servers without getting users and advertisers involved. We carry out experiments to examine the advertising running time under various number of servers and group sizes. We also argue about the optimum number of servers with respect to user privacy and advertising running time.
Formal Analysis of Mobile Multi-Factor Authentication with Single Sign-On Login
Authors: Sciarretta Giada , Carbone Roberto , Ranise Silvio , Viganò Luca
Published: June 2020

Over the last few years, there has been an almost exponential increase in the number of mobile applications that deal with sensitive data, such as applications for e-commerce or health. When dealing with sensitive data, classical authentication solutions based on username-password pairs are not enough, and multi-factor authentication solutions that combine two or more authentication factors of different categories are required instead. Even if several solutions are currently used, their security analyses have been performed informally or semiformally at best, and without a reference model and a precise definition of the multi-factor authentication property. This makes a comparison among the different solutions both complex and potentially misleading. In this article, we first present the design of two reference models for native applications based on the requirements of two real-world use-case scenarios. Common features between them are the use of one-time password approaches and the support of a single sign-on experience. Then, we provide a formal specification of our threat model and the security goals, and discuss the automated security analysis that we performed. Our formal analysis validates the security goals of the two reference models we propose and provides an important building block for the formal analysis of different multi-factor authentication solutions.
Enumerating Minimal Dominating Sets in Kt-free Graphs and Variants
Authors: Bonamy Marthe , Defrain Oscar , Heinrich Marc , Pilipczuk Michał , Raymond Jean-Florent
Published: June 2020

It is a long-standing open problem whether the minimal dominating sets of a graph can be enumerated in output-polynomial time. In this article we investigate this problem in graph classes defined by forbidding an induced subgraph. In particular, we provide output-polynomial time algorithms for

K
t

-free graphs and for several related graph classes. This answers a question of Kanté et al. about enumeration in bipartite graphs.
Improved Dynamic Graph Coloring
Authors: Solomon Shay , Wein Nicole
Published: June 2020

This article studies the fundamental problem of graph coloring in fully dynamic graphs. Since the problem of computing an optimal coloring, or even approximating it to within n1-εfor any ε > 0, is NP-hard in static graphs, there is no hope to achieve any meaningful computational results for general graphs in the dynamic setting. It is therefore only natural to consider the combinatorial aspects of dynamic coloring or alternatively, study restricted families of graphs.

Toward understanding the combinatorial aspects of this problem, one may assume a black-box access to a static algorithm forC-coloring any subgraph of the dynamic graph, and investigate the trade-off between the number of colors and the number of recolorings per update step. Optimizing the number of recolorings, sometimes referred to as the recourse bound, is important for various practical applications. In WADS ’17, Barba et al. devised two complementary algorithms: for any β > 0, the first (respectively, second) maintains anO(Cβn1/β)(respectively,O(Cβ)-coloring while recoloring O(β) (respectively, O(βn1/β)) vertices per update. Barba et al. also showed that the second trade-off appears to exhibit the right behavior, at least for β = O(1): any algorithm that maintains aC-coloring of ann-vertex dynamic forest must recolor Ω (n2C(C-1)) vertices per update, for any constant C ≥ 2. Our contribution is twofold:

• We devise a new algorithm for general graphs that improves significantly upon the first trade-off in a wide range of parameters: for any β > 0, we get a Ô (Cβlog2n)-coloring with O(β) recolorings per update, where the Ô notation suppressespolyloglog(n)factors. In particular, for β = O(1), we get constant recolorings withpolylog(n)colors; not only is this an exponential improvement over the previous bound but also it unveils a rather surprising phenomenon: the trade-off between the number of colors and recolorings is highly non-symmetric.

• For uniformly sparse graphs, we use low out-degree orientations to strengthen the preceding result by bounding the update time of the algorithm rather than the number of recolorings. Then, we further improve this result by introducing a new data structure that refines bounded out-degree edge orientations and is of independent interest. From this data structure, we get a deterministic algorithm for graphs of arboricity ɑ that maintains an O(ɑ log2n)-coloring in amortized O(1) time.
Debugging Incidents in Google’s Distributed Systems
Authors: Chan Charisma , Cooper Beth
Published: June 2020

This article covers the outcomes of research performed in 2019 on how engineers at Google debug production issues, including the types of tools, high-level strategies, and low-level tasks that engineers use in varying combinations to debug effectively. It examines the research approach used to capture data, summarizing the common engineering journeys for production investigations and sharing examples of how experts debug complex distributed systems. Finally, the article extends the Google specifics of this research to provide some practical strategies that you can apply in your organization.
Rutin via Increase in the CA3 Diameter of the Hippocampus Exerted Antidepressant-Like Effect in Mouse Model of Maternal Separation Stress: Possible Involvement of NMDA Receptors
Authors: Anjomshoa Maryam , Boroujeni Shakiba Nasiri , Ghasemi Sorayya , Lorigooini Zahra , Amiri Ahmad , Balali-dehkordi Shima , Amini-khoei Hossein
Published: June 2020

Background and Aim. Rutin is a flavonol with neuroprotective activity. The aim of the present study is to investigate the role of the glutamatergic system in the antidepressant-like effect of rutin in a mouse model of maternal separation (MS) stress focusing on histological changes in the CA3 area of the hippocampus. Methods. Mouse neonates were exposed to MS paradigm 3 hours daily from postnatal days (PND) 2 to 14. The control and MS mice were divided separately into 16 groups (n=8) (8 groups for each set) including mice that received normal saline, mice that received rutin at doses of 10, 50, and 100 mg/kg, mice that received NMDA at a dose of 150 mg/kg, mice that received ketamine (NMDA antagonist) at a dose of 0.25 mg/kg, mice that received NMDA antagonist plus a subeffective dose of rutin, and mice that received NMDA plus an effective dose of rutin. Forced swimming test (FST) was performed. Afterwards, the hippocampus was evaluated in cases of histopathological changes as well as expression of NR2A and NR2B genes. Results. Rutin significantly reduced immobility time in the FST. The expression of NR2A and NR2B subunits of NMDA receptor in MS mice was significantly higher than that in the control group. Rutin significantly decreased the expression of NR2B and NR2A subunits in the hippocampus. The CA3 diameter and percentage of dark neurons in the hippocampus of MS mice significantly decreased and increased, respectively, which partially reversed following rutin administration. Conclusion. Rutin, partially, through a neuroprotective effect on the hippocampus exerted antidepressant-like effect. We concluded that NMDA receptors, at least in part, mediated the beneficial effect of rutin.
Blood Pressure Variability and Atrial Fibrillation in Patients with Acute ST Segment Elevation Myocardial Infarction: The Relation with Left Atrial Electromechanical Delay – A 1-Year Follow-Up Study
Authors: Mahfouz Ragab A. , El-Shetry Mohamed , Frere Abdelfattah , Safwat Mohamed
Published: June 2020

Purpose: To investigate the association between 24-h blood pressure variability (BPV) and atrial electromechanical delay (EMD) in patients with ST segment elevation myocardial infarction (STEMI) who developed new-onset atrial fibrillation (NOAF). Materials and Methods: A total of 175 STEMI patients (age 56.6 ± 10.5 years) who underwent primary percutaneous coronary intervention were subjected to in-hospital 24-h ambulatory BP monitoring, comprehensive echocardiography, and assessment of atrial EMD. The parameters of BPV analyzed were: (a) 24-h standard deviation (SD), (b) the coefficient of variation, and (c) the average of the daytime and nighttime SDs weighted for the duration of the daytime and nighttime interval (SDdn). Results: Based on the median of BPV index (SDdn) = 9.5 mm Hg of all participants, patients were stratified into low and high variability groups (SDdn: 7.1 ± 1.5 vs.13.5 ± 2.9; p < 0.001). Of the 175 patients with STEMI, 29 (16.7%) patients developed NOAF; 26 (28.9%) were in the high variability group and 3.5% were in the low variability group (p < 0.001). Echocardiographic data showed that the left atrial volume index (p < 0.01) and E/e′ ratio (p < 0.001) were significantly higher in patients with high BPV. Inter and intra-atrial EMD were significantly increased in the high variability group compared to the low variability group (p < 0.001). With multiple linear analysis, there was significant correlation between SDdn and intra-left atrial and inter-atrial EMD (p < 0.001 and <0.01, respectively). Cox regression analysis revealed that SDdn and intra-atrial EMD were independent predictors for NOAF in patients with STEMI (OR = 3.75 and 02.72, respectively; p < 0.001). ROC analysis revealed that SDdn ≥12.8 was the optimal cut-off value for predicting NOAF during follow-up. Conclusions: Short-term BPV was associated with NOAF during the 1-year follow-up in patients with STEMI. In addition, BPV was correlated significantly with atrial EMD. Herein, BPV was predicted to be an early predictor of NOAF in patients with STEMI.
The effect of students of sports management and coaching education department on entrepreneurial tendencies of career plans
Authors: Vural Mustafa , Çoruh Yaşar
Published: June 2020

This study investigated the effect of career planning of the students in the Ağrı Ibrahim Çeçen University department of sports management and the coaching education department on entrepreneurial tendencies. The research group consisted of 161 students who studying in Ağrı Ibrahim Çeçen University Sports Management and Coaching Department. In the study, "Personal Career Planning Scale", which was developed by a researcher "Entrepreneurial Tendency Scale", which was developed by another researcher and "Personal Information Form", which was prepared by the researcher was used as a data collection tool. Spearman Correlation (r) coefficient technique was used to reveal the relationship between the career planning sub-dimensions and the entrepreneurial tendencies of the students. The effect between dependent and independent variables of the study was tested by regression analysis. In the correlation analysis performed at the end of the study, it was found that there was a positive relationship between all sub-dimensions of career planning scale and there was a positive and moderate relationship between the career planning and sub-dimensions and entrepreneurial tendencies. As a result of the regression analysis, the sub-dimension of defining opportunities and planning sub-dimension from the career planning has significantly affected the entrepreneurship and it
 explains 41% of the changes in entrepreneurship. It is possible to say that
 the participants who have the opportunities and have a plan are
 more entrepreneurs.
Exploring obstacles in language learning: Prospective primary school teacher in Indonesia
Authors: Asrial Asrial , Syahrial Syahrial , Kurniawan Dwi Agus , Subandiyo May , Amalina Nur
Published: June 2020

In the implementation of educational practices, Indonesian is used as the language of instruction. Teacher candidates are prepared to have language competence as their knowledge in carrying out classroom learning. Important language competence is owned by a prospective elementary school teacher to facilitate communication with students and design learning about language. In an effort to improve material understanding and mastery of good language competence, prospective teachers in Primary School Teacher Education have constraints in the learning process in tertiary institutions that are identified based on 9 indicators. These indicators consist of curriculum, practicum activities materials/tools, books/modules, initial abilities of prospective teachers, learning resources from outdoor learning, learning resources from outdoor language learning, learning resources from indoor learning, learning environments, motivating teacher candidates, and the ability to judge yourself. This study uses a qualitative research approach. This study aims to analyze the constraints students face in Indonesian language competence. The sample in this study were students in Primary School Teacher Education with a total of 30 respondents. Data collection using interview and documentation techniques.
Internal locus of control, social support and academic procrastination among students in completing the thesis
Authors: Sari Winda Liftiana , Fakhruddiana Fuadah
Published: June 2020

The basis of this study was to determine the relationship between internal locus of control and social support with students' academic procrastination in completing their thesis. This study is using correlational sampling technique and the research samples taken from quota sampling technique are 80 college students who are in the process of completing the thesis. The measuring instrument is the Academic Procrastination Scale in completing the thesis, Internal Locus of Control Scale and Social Support Scale. The regression analysis result that there is a very significant correlation between internal locus of control and social support with academic procrastination of the students in completing the thesis. Further analysis showed that there is a very significant negative correlation between internal locus of control with academic procrastination. This means that the lower level of internal locus of control, the higher level of academic procrastination in completing a thesis, and vice versa. Likewise, there is a very significant negative correlation between social support and academic procrastination in completing a thesis. This result means that the lower level of social support, the higher level of academic procrastination in completing a thesis, and vice versa.
Demand of ICT-based chemistry learning media in the disruptive era
Authors: Kumala Dewi Ratna , Wardani Sri , Wijayati Nanik , Sumarni Woro
Published: June 2020

The challenges of education in the era of the industrial revolution include disruption 4.0, 21st-century skills, globalization, and global competition. Chemistry is a subject that needs to be developed in order to improve the educational system in the era of disruption. The purpose of this research is to identify and analyze the needs of the media-based chemistry study ICT at grade X redox materials in State Senior Highschool 8 Semarang during the disruption. The method used in this research is a descriptive qualitative method which consists of the study of literature and the study of the field. Method of data collection is done through observation, question form, documentation, interview teachers, as well as interview students. This research instrument consisting of a sheet of observation, question form, and sheet interview. The results showed that chemical-based learning media limited ICT in State Senior Highschool 8 Semarang redox materials especially in class X. That is because of the teacher's difficulty in innovating to develop learning media chemistry-based ICT and lack of student understanding and literacy in the study of chemical materials. Teachers play an important role in order to educate the students towards the era of disruption. In this era of chemical subjects not only taught students with literacy (reading, writing, math) but the need for a new form of literacy the literacy data, technology, and human resources in order to overcome learning difficulties and improving students learning outcomes for better value.
Teacher and student interactions and characteristics from critical theorists school
Authors: Salehi Akbar
Published: June 2020

In recent years, critical thinkers have done serious discussions in education and other fields in our lives like social, cultural, political and economical. This paper is going to consider some of the critical thinkers’ theories in order to clarify teacher and student interactions in education. The research is a type of fundamental and qualitative study which frames teacher and student interactions by means of a descriptive – analytical method. Accordingly, we introduce critical teacher as a teacher who includes specific characteristics like emancipation, critical nature and openness. Therefore mentioned teacher attends the role of culture in human life and he resists reproduced by the regime. He is someone who provides the way for public hearing; in addition, he teaches his students how to resist domination. On the other side, a student in this school will not be dominated by the regime by means of its essential tools as probe and questioning. A student has been taught to hear everyone regardless of race, religion and social class. Finally, this paper proposes applying these ideas for educational systems informal and operational ways.
Review of the effects of technical assistance on program, organization and system change
Authors: Dunst Carl J. , Annas Kimberly , Wilkie Helen , Hamby Deborah W
Published: June 2020

Findings from a synthesis of technical assistance models and frameworks were used to code the use of 25 core elements of technical assistance in studies and evaluations of implementation interventions to affect program, organization, and systems change. The 25 core elements were group into five components: preparation for the provision of technical assistance, development of a technical assistance plan, implementation of technical assistance, evaluation of the effects of technical assistance, and sustainability of technical assistance-facilitated changes. Results indicated that a subset of 11 core elements was related to between groups and between condition differences in the sizes of effect for program, organization, and systems changes. Results also showed that more intensive technical assistance was associated with larger sizes of effects compared to less intensive technical assistance and that particular combinations of practices were associated with the largest sizes of effect.
Student employability examined from academic achievement and self-concept
Authors: Tentama Fatwa , Abdillah Muhamad Hasan
Published: June 2020

Employability is a problem that often arises in its relation to job-seeking, where low employability has become an obstacle for individuals entering the workforce. Factors believed to influence levels of employability are academic achievements and self-concept. This study aimed to determine the relationship between academic achievement and self-concept with student employability. The subjects in this study were 85 students who were obtained through cluster random sampling. The research method used is a quantitative method, utilizing scales and report card scores as data collection tools. The scale used is scale of employability and self-concept. The data analysis used in this study is multiple linear regression analysis. The results of the data analysis showedsignificant relationship between academic achievement and self-concept with employability.
Motivation to learn and social support determine employability among vocational high school students
Authors: Tentama Fatwa , Subardjo Subardjo , Abdillah Muhamad Hasan
Published: June 2020

One of the factors that influence the level of employability is the motivation to learn and social support. This study aims to determine the effect of motivation to learn and social support on student employability. The participants in this study were 255 students of class XII in State Vocational High School 1 Kalasan Yogyakarta, obtained through random cluster sampling. The data collection was carried out by using an employability scale, motivation to learn scale and social support scale. The data analysis used in this study was multiple linear regression analysis. Our data analysis shows that motivation to learn and social support have a very significant effect on employability, seen through the F test that obtained a score of 44.798 and a significance level (p) of 0.000 (p <0.01). In other words, the level of employability could be predicted based on students' level of motivation to learn and social support.
The competencies of principals in ensuring sustainable education: Teachers' views
Authors: Şemin Fatma Köybaşı
Published: June 2020

This study aimed to reveal the opinions of teachers about the competencies of school administrators in order to ensure the sustainability of education in schools. It was a pneumology study designed with qualitative research method. The study group consists of fifteen teachers from schools located in five different educational zones across the center of Sivas, a city in Central Turkey. Study data were analyzed with content analysis to determine the factors that provide educational sustainability in schools. According to the results; solidarity and structured work characteristics among school administrators to fulfill the objectives of the school affect the adequacy of education in a positive way; while institutionalism and limiting of the capacity have an opposite effect. In relation to capacity building for taking the school culture to future, school administrators have a high opinion of opening up to the neighborhood besides school culture supply and demand. Lastly, for carrying the school into the future, teachers expect school leaders to exhibit behaviors with emphasis on specific themes as ethics, motivation, and awareness.
Examining the measurement invariance of the teachers' sense of self-efficacy scale in terms of gender
Authors: Doğan Yıldız Burcu , Akar Huseyin , Üstüner Mehmet
Published: June 2020

The aim of this research was to analyze the measurement invariance of the "Teachers' Sense of Self-Efficacy Scale," developed by Tschannen-Moran and Hoy, and adapted into Turkish and Turkish culture by Çapa, Çakıroğlu and Sarıkaya, with respect to gender. Turkish version of the scale consists of 24 items and 3 subscales. The scale measures pre-service teachers' and teachers' sense of and belief in self-efficacy for student engagement, classroom management and instructional strategies. Research revealed that the scale is being used by a myriad of researchers. The sample of this study consists of 267 female, 163 male pre-service teachers who participated in the Pedagogical Formation Certificate Traning at Inönü University in the 2017-2018 academic years. First of all, CFA was executed in order to confirm the validity of the scale's current structure for both genders which was confirmed based on the analysis results. Then, MGCFA was executed to analyze the scale's measurement invariance in terms of gender. The results of the MGCFA indicated that the scale has the measurement invariance with respect to gender at each of the stages of strict, metric, scalar and
 configural invariance.
Students’ attitude towards natural sciences
Authors: Kurniawan Dwi Agus , Astalini Astalini , Darmaji Darmaji , Melsayanti Ririn
Published: June 2020

The purpose of research was to investigate students’ attitudes towards natural science in Muaro Jambi, Indonesia. The attitude of the students studied was represented by three indicators, namely the attitude towards the investigation in the Natural Sciences, the adoption of a scientific attitude, and a career interest in the science field. The research was a survey research. The instruments in this study were attitude questionnaires and interview sheets. Data analysis techniques for attitude questionnaires used descriptive statistics while for analyzing interview data using the Miles and Huberman model.The study found students’ good attitudes towards natural science subjects.
Determination of the level of pedagogical formation students’ academic locus of control
Authors: Can Süleyman , Durukan Erdil
Published: June 2020

Academic locus of control has an important place in explaining students’ behaviors in educational settings. The purpose of the current study is to determine the level of the pedagogical formation students’ academic locus of control and to investigate whether this level varies depending on some variables. The study employed the survey model, one of the quantitative research methods. The universe of the study is comprised of the students enrolled at the pedagogical formation program initiated in the fall term of 2015-2016 academic year in Muğla Sıtkı Koçman University and the sampling consists of 397 pedagogical formation students. As the data collection tool, the academic locus of control scale was used in the current study. It was concluded that the pedagogical formation students’ level of academic locus of control is medium. It was also found that the students’ academic locus of control, internal locus of control and external locus of control do not vary significantly depending on gender and department; yet, vary significantly depending on age. Furthermore, the pedagogical formation students’ level of satisfaction was found to be significantly correlated with the external locus of control but not with the internal locus of control and academic locus of control.
Examining pre-service social studies teachers’ sensitivity levels based on various variables
Authors: Çelik Ayşegül
Published: June 2020

The purpose of this study is to determine whether or not pre-service Social Studies teachers’ interpersonal sensitivity levels significantly vary depending on various variables. The study employed the quantitative model to determine pre-service Social Studies teachers’ sensitivity levels. The survey model was used as a quantitative model. The study group consists of 80 pre-service teachers studying in the Social Studies Teaching department of a state university located in the Central Anatolian Region of Turkey. The study used a personal information form to find out the pre-service teachers’ demographic information. The personal information form includes descriptive information about age, gender, and grade. The study also used the sensitivity. The scale analysis was made via SPSS. The data were analyzed through independent samples t-test and one-way analysis of variance (ANOVA). The data were collected by the researcher in the 2018-2019 academic year. The pre-service Social Studies teachers’ general average of consciousness was found to be high.
Learning styles and teacher efficacy among prospective teachers based on diverse variables
Authors: Atalay Tazegül Demir
Published: June 2020

The main aim of this study was to explore learning styles and teacher efficacy of prospective teachers, evaluate them based on department, gender, high school type and educational level of parents, and identify whether there is any relationship between teacher efficacy and learning styles. This is a descriptive study that was conducted using survey model. The study group consisted of 170 prospective teachers in the Faculty of Education, Kafkas University during the 2018-2019 academic year. Research data were gathered through “Teachers’ Sense of Efficacy Scale” and the “Kolb Learning Style Inventory”. The study came to the conclusion that prospective teachers mostly had diverging and converging learning styles while assimilating and accommodating learning styles were least preferred, their teacher efficacy was "sufficient", and teacher efficacy scores differed significantly in relation to learning styles. The study also found a significant relationship between some variables, i.e. department, gender, high school type and educational level of parents, and the prospective teachers' learning style and occupational self-efficacy level. The study discussed these findings from various aspects and proposed recommendations.
A computerized adaptive test for measuring the physics critical thinking skills in high school students
Authors: Abidin Aang Zainul , Istiyono Edi , Fadilah Nunung , Dwandaru Wipsar Sunu Brams
Published: June 2020

Classical assessments that are not comprehensive and do not distinguish students' initial abilities make measurement results far from the actual abilities. This study was conducted to produce a computerized adaptive test for physics critical thinking skills (CAT-PhysCriTS) that met the feasibility criteria. The test was presented for the physics subject of 11th grade high school students with two-tier multiple-choice format. This development research was based on the 4-D model combined with the test development model by Oriondo & Antonio. Eleven experts and 577 11th grade high school students in Kulonprogo, Indonesia, have participated. The media feasibility and the content validity of the items was assessed by experts, while item and abilities parameters were estimated by item response theory. The results obtained: 1) CAT media was declared very feasible and content validity of 136 items was declared valid; 2) all items fitted to partial credit model, the item reliability was classified as good, and the difficulty index of items was good; 3) the results of the CAT-PhysCriTS were equivalent to students academic achievement. Based on the results, CAT-PhysCriTS has fulfilled the requirements as a measuring instrument with measurement times were faster and more comprehensive for large-scale assessments.
Parameter estimation bias of dichotomous logistic item response theory models using different variables
Authors: Köse Alper , Doğan C. Deha
Published: June 2020

The aim of this study was to examine the precision of item parameter estimation in different sample sizes and test lengths under three parameter logistic model (3PL) item response theory (IRT) model, where the trait measured by a test was not normally distributed or had a skewed distribution.In the study, number of categories (1-0), and item response model were identified as fixed conditions, and sample size, test length variables, and the ability distributions were selected as manipulated conditions. This is a simulation study. So data simulation and data analysis were done via packages in the R programming language. Results of the study showed that item parameter estimations performed under normal distribution were much stronger and bias-free compared to non-normal distribution. Moreover, the sample size had some limited positive effect on parameter estimation. However, the test length had no effect parameter estimation. As a result the importance of normality assumptions for IRT models were highlighted and findings were discussed based on relevant literature.