bluuebunny/crossref_metadata_2025 huggingface dataset:
Tissue Oximetry Readings Accurately Predict Late Complications in Patients Undergoing Free Flap Breast Reconstruction: Exploring the Optimal Cut Point Value
Authors: Saad Noah , Wang Howard , Karamanos Efstathios
Published: May 2020

Background The use of tissue oximetry for monitoring following free tissue transfer has become a common practice across the United States to facilitate early detection of poor flap perfusion in the postoperative setting. There is no consensus on the optimal value, below which there is a higher chance of wound complications in patients undergoing free flap breast reconstruction.

Methods Patients undergoing free flap breast reconstruction from 2015 to 2018 were retrospectively reviewed. Patients who returned to the operating room for a revision of the anastomosis were excluded from analysis. Patients were divided in two groups based on the development of late complications. Those were defined as fat necrosis, wound dehiscence, or distal flap ischemia/necrosis that developed after discharge from the hospital. Mean percutaneous oximetry readings of the first 24 hours were recorded and the mean change from the initial reading was calculated. The correlation between tissue oximetry change and development of complications was explored.

Results A total of 120 patients were identified. The mean age was 53, while the mean body mass index was 33. A total of 38 patients developed late wound complication. History of smoking, diabetes mellitus, neoadjuvant radiation therapy, and the mean change of the tissue oximetry reading were identified as independent predictors of wound complications. The absolute number of the tissue oximetry reading did not predict late complications. A multivariate analysis revealed that patients who experienced a mean decrease < 15% from the initial reading during the first 24 hours were significantly more likely to develop late flap-related wound complications.

Conclusion In patients undergoing free tissue breast reconstruction, tissue oximetry readings do not predict late wound complications. However, the mean change at 24 hours from the initial reading does. A decrease of <15% in tissue perfusion was associated with a significant increase in the probability of developing flap-related wound complications.
The Impact of Indocyanine-Green Fluorescence Angiography on Intraoperative Decision-Making and Postoperative Outcome in Free Flap Surgery
Authors: Bigdeli Amir Khosrow , Thomas Benjamin , Falkner Florian , Gazyakan Emre , Hirche Christoph , Kneser Ulrich
Published: May 2020

Background Reliable perfusion of the distal portions of free flaps is decisive for the reconstructive success. Indocyanine green near-infrared video angiography (ICG-NIR-VA) has been adopted for objective assessment of free flap tissue perfusion but is thus far not used on a routine basis. Therefore, we investigated its intraoperative impact on decision-making and postoperative outcome.

Methods From January 2017 to June 2019, 88 consecutive adipo- or fasciocutaneus free flaps were performed in conjunction with intraoperative ICG-NIR-VA. Free flap tissue perfusion was first assessed clinically and then compared with ICG-NIR-VA findings. Based on the results, the decision for intraoperative trimming of critically perfused flap zones was made. The way of decision-making, flap success, and failure rates as well as intra- and postoperative complication rates were analyzed.

Results The overall free flap success rate was 92.0%. Partial flap necrosis occurred in five cases (5.7%) and total flap necrosis in two cases (2.3%). ICG-NIR-VA aided decision-making and flap design in 34 cases (38.6%) and led to complication-free postoperative courses. When ICG-NIR-VA was relied on (82 out of 88 flaps; 93.2%), there was no unpredicted postoperative tissue necrosis (overestimation). When ICG-NIR-VA was not relied on (6 out of 88 flaps; 6.8%), there were five cases of postoperative partial flap necrosis and one case of uneventful healing (underestimation). The sensitivity of ICG-NIR-VA was 100% (95% confidence interval [CI]: 64.6–100) and the specificity was 98.8% (95% CI: 93.3–100) with a positive predictive value of 87.5% (95% CI: 52.9–99.4) and a negative predictive value of 100% (95% CI: 95.4–100).

Conclusion Intraoperative ICG-NIR-VA objectified free flap perfusion and thus refined surgical decision-making on flap design in all cases. It could always predict tissue necrosis and subjectively improved outcomes in free flap surgery at our institution. Furthermore, it could be easily implemented in intraoperative routine, only adding minimal additional operative time.
Nondiagonal terms in the second moment of automorphic

-functions
Authors: Frolenkov D. A.
Published: May 2020

We investigate the exact formula for the second moment of central

-values associated to primitive cusp forms of level one and weight

,

, which was proved by Kuznetsov in 1994. Nondiagonal terms in this formula are expressed in terms of several convolution sums of divisor functions. We investigate the main terms of the convolution sums and show that they cancel out.

Bibliography: 8 titles.
Endogenous oxidized DNA bases and APE1 regulate the formation of G-quadruplex structures in the genome
Authors: Roychoudhury Shrabasti , Pramanik Suravi , Harris Hannah L. , Tarpley Mason , Sarkar Aniruddha , Spagnol Gaelle , Sorgen Paul L. , Chowdhury Dipanjan , Band Vimla , Klinkebiel David , Bhakat Kishor K.
Published: May 2020

Formation of G-quadruplex (G4) DNA structures in key regulatory regions in the genome has emerged as a secondary structure-based epigenetic mechanism for regulating multiple biological processes including transcription, replication, and telomere maintenance. G4 formation (folding), stabilization, and unfolding must be regulated to coordinate G4-mediated biological functions; however, how cells regulate the spatiotemporal formation of G4 structures in the genome is largely unknown. Here, we demonstrate that endogenous oxidized guanine bases in G4 sequences and the subsequent activation of the base excision repair (BER) pathway drive the spatiotemporal formation of G4 structures in the genome. Genome-wide mapping of occurrence of Apurinic/apyrimidinic (AP) site damage, binding of BER proteins, and G4 structures revealed that oxidized base-derived AP site damage and binding of OGG1 and APE1 are predominant in G4 sequences. Loss of APE1 abrogated G4 structure formation in cells, which suggests an essential role of APE1 in regulating the formation of G4 structures in the genome. Binding of APE1 to G4 sequences promotes G4 folding, and acetylation of APE1, which enhances its residence time, stabilizes G4 structures in cells. APE1 subsequently facilitates transcription factor loading to the promoter, providing mechanistic insight into the role of APE1 in G4-mediated gene expression. Our study unravels a role of endogenous oxidized DNA bases and APE1 in controlling the formation of higher-order DNA secondary structures to regulate transcription beyond its well-established role in safeguarding the genomic integrity.
Chloroplast Sec14-like 1 (CPSFL1) is essential for normal chloroplast development and affects carotenoid accumulation in
Chlamydomonas
Authors: García-Cerdán José G. , Schmid Eva M. , Takeuchi Tomomi , McRae Ian , McDonald Kent L. , Yordduangjun Nichakarn , Hassan Ahmed M. , Grob Patricia , Xu C. Shan , Hess Harald F. , Fletcher Daniel A. , Nogales Eva , Niyogi Krishna K.
Published: May 2020

Significance

Carotenoids are essential molecules in oxygenic photoautotrophs, and they fulfill essential requirements for human and animal nutrition. How carotenoid accumulation is regulated in the chloroplast, a cyanobacterium-derived organelle, remains poorly understood, despite significant advancements in identifying enzymes of the carotenoid biosynthetic pathway. This study identifies a role of chloroplast Sec14-like 1 (CPSFL1), a CRAL-TRIO protein of eukaryotic origin, in modulation of carotenoid biosynthesis and accumulation in the chloroplast. The CPSFL1 protein represents an isoprenoid- and carotenoid-binding protein that associates with membranes through interactions with the phospholipid phosphatidic acid. These findings have implications for understanding carotenoid biosynthesis and optimizing algal carotenoid nutritional quality.
Rad51 facilitates filament assembly of meiosis-specific Dmc1 recombinase
Authors: Lan Wei-Hsuan , Lin Sheng-Yao , Kao Chih-Yuan , Chang Wen-Hsuan , Yeh Hsin-Yi , Chang Hao-Yen , Chi Peter , Li Hung-Wen
Published: May 2020

Significance

DNA recombinases Dmc1 and Rad51 are both required during meiosis in most eukaryotes. Although they share high identity in amino acid sequence and biochemical properties, the mechanism of the requirement is unclear. The presynaptic filament formation is the first committed step in the process of homologous recombination. In this study, we combined the ensemble-based and the single-molecule experiments to dissect the assembly mechanism of Dmc1. Our results show that Dmc1 recombinases possess evolutionarily conserved nucleation preference that allows 5′-to-3′ filament formation. Moreover, Rad51 patches on single-stranded DNA stimulate the assembly of Dmc1, demonstrating the ability of Rad51 to facilitate the filament formation of Dmc1 in meiosis. The results provide a molecular rationale of why both recombinases are required in meiosis.
The airborne lifetime of small speech droplets and their potential importance in SARS-CoV-2 transmission
Authors: Stadnytskyi Valentyn , Bax Christina E. , Bax Adriaan , Anfinrud Philip
Published: May 2020

Speech droplets generated by asymptomatic carriers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are increasingly considered to be a likely mode of disease transmission. Highly sensitive laser light scattering observations have revealed that loud speech can emit thousands of oral fluid droplets per second. In a closed, stagnant air environment, they disappear from the window of view with time constants in the range of 8 to 14 min, which corresponds to droplet nuclei of
ca.
4 μm diameter, or 12- to 21-μm droplets prior to dehydration. These observations confirm that there is a substantial probability that normal speaking causes airborne virus transmission in confined environments.
Tenor
Authors: Hasan Ruqaiya
Published: May 2020

This paper presents work-in-progress on the contextual variable tenor, here reconceptualised as ‘interactant relations’ in order to explore a radically different view of the relations of the interactants to the text in context. The functions of speaker/addressee are the starting point of an exploration of interactant relations because they represent the only features with the capacity to manage a text’s processes. This view implies that speaker/addressee have the capacity to internalise communal conventions, which places them at the centre of the language process. Implications of the results of the exploration for the classification of register are proposed. The paper’s methodology extends previous work on contextual networks (see especiallyHasan 2001a,2009b,2014,2016).i
Strain partitioning between matrix and precipitates during fatigue deformation of 2.25Cr–Mo steel
Authors: Rajpurohit R. S. , Jena P. S. M. , Mahato B. , Sahu J. K.
Published: May 2020

The influence of stress rate [Formula: see text] on load/strain partitioning between different phases of a micro-alloyed 2.25Cr–Mo steel during stress-controlled fatigue deformation at room temperature (RT) was studied by conducting asymmetrical ratcheting fatigue tests employing [Formula: see text] values of 50–450 MPa/s. Fatigue life ( Nf) significantly reduced for tests conducted by employing [Formula: see text]  = 50 MPa/s compared to 450 MPa/s, i.e. Nf = 510 and 24,983 cycles respectively. From TEM studies, it is confirmed that due to load/strain partitioning stacking faults (SFs)/micro-twin formed in M23C6 carbides during high [Formula: see text] fatigue deformation, whereas dislocation cells are formed in low [Formula: see text] fatigue deformation. A plausible explanation to account for different cycle life with change in [Formula: see text] of fatigue deformation is offered.
FMRP differentially regulates BK channels
Authors: Short Ben
Published: May 2020

Study suggests that the fragile X syndrome-associated protein FMRP can interact with different types of BK channels and modulate their kinetics in different ways.
Selection of Indian Cricket Team in ODI using Integer Optimization
Authors: Agrawal Prachi , Ganesh Talari
Published: May 2020

The selection criterion of a cricket team depends on so many factors like average, strike rate, consistency, economy rate, etc. For every factor, it may get a different team, but consistency plays an important role in the selection process. This paper outlines the selection process of players in the Indian Cricket Team for the ODI. A criterion is proposed for the evaluation of different factors on which the selection process can be done. This evaluation describes the consistent and inconsistent players and ranks of them. The players will be chosen at different categories like batsmen, bowler, all-rounder, and wicketkeeper. The evaluation mainly based on the consistency of the player. For this measure, integer optimization programming has been applied, and data has been taken from Jan 2015 to Sept 2017 of ODI matches.
Image Captioning and Comparison of Different Encoders
Authors: Pal Ankit , Kar Subasish , Taneja Anuveksh , Kumar Jadoun Vinay
Published: May 2020

Generation of a sentence given an image, called image captioning, has been one of the most intriguing topics in computer vision. It incorporates knowledge of both image processing and natural language processing. Most of the current approaches integrates the concepts of neural network. Different predefined convolutional neural network (CNN) models are used for extracting features from an image and uni-directional or bi-directional recurrent neural network (RNN) for language modelling. This paper discusses about the commonly used models that are used as image encoder, such as Inception-V3, VGG19, VGG16 and InceptionResNetV2 while using the uni-directional LSTMs for the text generation. Further, the comparative analysis of the result has been obtained using the Bilingual Evaluation Understudy (BLEU) score on the Flickr8k dataset.
Automatic generation control for single area power system using GNA tuned PID controller
Authors: Choudhary R , Rai J N , Arya Y
Published: May 2020

This work investigates Automatic Generation Control in the one area thermal power system and optimization of gain parameters of conventional controller for non-reheat and reheat thermal power systems. Proportional – integral – derivative (PID) controller and PI controller is used for the comparison. The tuning of controller gain parameters is obtained by Integral Time Absolute Error (ITAE) approach for optimization. The proposed work utilizes new meta-heuristic algorithm for tuning of controller gain parameters. The GNA algorithm proved to be effective and robust for tuning a controller in the presence and absence of appropriate Generation Rate Constraint (GRC). The performance comparison and verification of simulation results is shown in time domain using Matlab. Finally, simulation result reveals that new GNA tuned PID controller provides more superior response in comparison to PI controller with and without including the effect of GRC.
Improved chain based cooperative routing protocol in wsn
Authors: Kumar Maurya Awadhesh , Varsha  , Neeraj  , Kumar Ajay , Kumar Neeraj
Published: May 2020

Energy preservation of the sensor become a prime objective of the routing protocols for prolong the period of sensor network and for efficient running of wireless sensor network applications. Taking this aspect into consideration, improved CBCCP approach has been developed that take energy, distance and node Density as parameter to choose cluster head (CH) and cluster-coordinator (CC). In Improved CBCCP, the network is partitioned into layers of fixed measurements and each cluster has one CH and varied no. of CC. Each CH and CC has the load of one cluster just to adjust the load. Data transmit to CH through normal nodes using single hop approach .Data transmitted to base station through cluster coordinator in type of chain. Communication distance is decreased by utilizing cluster coordinator for Intracluster communication and cluster head for inter-cluster communication. In comparison with CBCCP, Improved CBCCP balances the energy and prolongs the period of sensor network.
A Comparative study of copy-move forgery detection methods
Authors: Agarwal Ritu , Verma Om Prakash
Published: May 2020

Images hold a major influential power, as evidence or as a medium to convey messages. An image is worth a thousand words and is used extensively in this era for digital communications. Hence, their tampering can cause major losses, which is why their manipulations techniques have grown sophisticated over time. Copy-move forgery is a technique, wherein an area of an image is replicated to another area of the image. The paper reviews state of the art copy-move forgery detection (CMFD)methods listing the approach and limitations of various techniques with the help of a table for better readability.
Isolation through a viscoelastic surfactant of a fracable hydrocarbon-containing formation
Authors: Kuchin Viacheslav , Dvoynikov Mikhail , Nutskova Mariia
Published: May 2020

In this paper water cut of well products problem is considered. To solve this problem it is proposed to use a technology of water inflows isolation during the drilling process developed by the authors. Not only does our approach stimulates the production of hard-to-recover hydrocarbons but it also protects local water and undisturbed geological formations against the impact of hydraulic fracturing operations. This approach also enables higher well potential due to a longer service life of the wellbore. The use of a device-pressure regulator with synchronous injection of the developed blocking fluid is presented. Mathematical modeling of the experiment was performed, aimed at determining the dependence of the change in pressure drop in the annular space of the well on the flow conditions of the blocking composition with a device installed in the bottom hole assembly that will effectively apply the controller device, taking into account the drilling parameters of a particular well. The novelty of this approach lies in the fact that this work offers an aquifer isolation technology, which suggests applying a pressure regulating device, and provides a layout of a blocking viscoelastic system.
Coverage Based Test Suite Minimization using UML Behavioural Diagrams
Authors: Gupta Rashmi , Jaglan Vivek
Published: May 2020

There is an important role of software systems testing in the software development cycle. The software testing is used to reveal errors in software which enhances overall quality and efficiency of the software. The approach followed for software testing should be such that it can detect maximum number of errors in minimum time which can lower the effort spent in maintenance phase. Coverage criteria are very important to analyze test cases which can be useful in fault coverage and minimizing the test suite. As it takes a lot of time in the software system testing, so minimizing the test cases can help in minimizing the overall effort required to lower the testing time. Test cases should be selected such that they are covering maximum of activities, basic path and conditions present in the graph and taking less time while executing.
Selection of Optimal Tire and Design Optimisation of Steering System for a Formula Student Race Car through Tire Data Treatment
Authors: Swamy Varsha S , Karan Shivayogi H G , Rajesh Mathivanan N
Published: May 2020

Selection of tires plays a crucial role in Vehicle Dynamics, which is important to design the steering and suspension system. An attempt is made to select the most optimum tire for lateral performance by using the tire data acquired from Tire Testing Consortium. Parameters including the tire’s lateral grip, cornering stiffness, cornering stiffness coefficient, camber stiffness, and lateral frictional coefficient have aided this selection. The tire is modelled using the Pacejka Magic Formula where the lateral and aligning coefficients are found, and used to get pneumatic trail, a parameter not provided in the raw data. The novelty of the work is seen when the selected tire is analysed to set the camber, pressure, and caster using the Design of Experiments method, without the need for building and testing a car. Making the best use of the tires’ forces and moments, the steering geometry is designed for a target range of radii by operating the tire slip angles at its optimum value. Further the influence of the change in toe angle on the Ackermann percentage is examined. Steering moment, calculated using the aligning moment curves of the tire, is applied to the steering column to conduct finite element analysis.
A Radial Basis Function Neural Network Based Approach to Mitigate Soiling from PV Module
Authors: Kumar Sujit , Kamal Neel , Gaur Aditya , Pathak Mohit , Shrinivas Kumar , Singh Priyanshu
Published: May 2020

Solar power is available in abundance and is free of cost but despite this fact photovoltaic (PV) systems are not reliable as the efficiency of PV module is still not up to the mark. Amount of sun light absorbed by the module is the fuel for the PV modules, there are many factors which play a vital role such as front surface reflectivity, solar beam incidence angle and the most important is the transmissivity of the front surface. Objective of this paper is to examine the function of a neural network based model of a module to mitigate the soiling and improve the accuracy of dust prediction over the module and enhance the efficiency which was degraded by soiling. One of the techniques in artificial intelligence named, radial basis function neural networks (RBFNN) is utilized here to predict the dust data by reading the data of solar irradiance, module temperature, PV voltage, current and power and generates the control signal to the windshield wiper motor that drives the wiper to wipe the dust from the panel. A considerable measure of accessible exploratory information was utilized for the preparation of the RBFNN, and a back propagation algorithm was utilized.
Mathematical critical thinking ability of students with realistic mathematics learning innovations with ethnomathematics (PMRE)
Authors: Muslimahayati  , Dasari D , Agustiani R
Published: May 2020

The importance of critical thinking ability is on the demands with the current curriculum which wants students to have the ability to analyze and solve problems, especially in everyday life. However, this ability is still not explored maximally by the teacher in classroom learning. Therefore, this study examines the improvement of critical thinking ability among students who obtained the PMRE approach with students who obtained conventional learning, reviewed as a whole and reviewed according to the high, medium and low mathematical initial ability categories. This research is a quasi-experimental study with nonequivalentpre-test and post-test control-group design. The data obtained were analyzed using the mean difference test namely t-test and mann-whitney. The results showed that: 1) the improvement of critical thinking skills of students who received PMRE approach as a whole was better than students who obtained conventional learning with a moderate category 2) reviewed from mathematical initial ability, increased critical thinking skills of students in the medium category who were getting PMRE learning more better than students who get conventional learning, while for high and low students who get PMRE learning is no better than students who get conventional learning.
Design of mathematics learning in the grand mosque of palembang
Authors: Martadinata I , Somakim  , Darmawijoyo  , Araiku J
Published: May 2020

This study aims to describe the role of the context of the Grand Mosque of Palembang to support the mathematics learning process and produce learning trajectories to help students in understanding quadrilateral material (square, rectangle, and isosceles trapezoid) with RME approach. The methodology in this research is design research, consisting of preliminary design, design experiment, and retrospective analysis. The subjects are seventh graders of MTSN 1 Palembang. The instruments in this research are videos, documentation, student activity sheets, pre-test, and post-test. The results show that the context of the Grand Mosque of Palembang helps students to compare and connect the perimeter and area of a rectangular plane. All strategies and models that students find, describe and discuss, show how the construction and contribution of students help their initial understanding of the topic. In experience based activity, comparing and connecting the perimeter and area of rectangular plane holds an important role in transitioning from informal to formal levels.
Development of proof-based student worksheets in trigonometry
Authors: Ismerelda I , Hartono Y
Published: May 2020

Research has been conducted for: (1) Developing student worksheets based on valid trigonometric mathematical proofs, (2) Developing student worksheets based on practical trigonometric mathematical proofs and (3) Knowing the advantages and limitations of validation student product based on trigonometric mathematical proof developed. The research method used is research and development (R&D) with a development model developed by Rowntree, using three stages, namely: (1) the planning stage, (2) the development phase and, (3) the evaluation phase. The results of data analysis can be concluded The results give meaning that the developed: (1) is appropriate and appropriate to use, because it is in accordance with core competencies, basic competencies, indicators, objectives, scenarios of teaching and learning activities and has phases that are measurable and clearly easily understood by students and can develop Student that have been developed to meet the eligibility as a good Student, (2) both at one to one stage and small groups based on the criteria of practical use for each indicator in the practicality category on good level. (3) Excellence Developed Students can increase motivation, foster interest in learning, foster an attitude of confidence, can foster an honest attitude, increase discipline and foster cooperation among fellow students.
Students’ characters in solving higher-order thinking skill questions assisted with technology
Authors: Suci A , Aisyah N , Meryansumayeka
Published: May 2020

The purpose of this study was to describe students characterr in solving HOT (Higher order thinking) questions assisted with ICT (Information and Communication of Technology). Research conducted is a descriptive qualitative research. This study have 4 focus characters namely hard work, creative, thorough, and curiosity. The subject in this study is 4 students of class XI IPS SMA Srijaya Negara Palembang. Data collection in this study include tests, interview, observation, documentation, and using triangulation techniques of data collection to check the validity of the data instrument. The results of this study indicate that the most dominant character values appeared during the learning process with HOT and ICT-assisted media are the value of hard work and curiosity.
Ethnomathematics-based learning using oil palm cultivation context
Authors: Marleny A S , Somakim  , Aisyah N , Darmawijoyo  , Araiku J
Published: May 2020

Agriculture is a culture that has been embedded in Indonesian society. Along with the changing times, then this culture began to be abandoned and tend not to be known by the current generation. Ethnomathematics exists to bridge the gap between culture and education. The purpose of this study was to find out the mathematical ideas on oil palm cultivation and determine students’ responses in Ethnomathematics-based learning. This research uses descriptive qualitative. In this study, an assessment of the knowledge, ideas, or findings contained in the literature was carried out to provide theoretical information and interviews to oil palm companies and smallholders related to oil palm cultivation and implemented in mathematics learning. The application of agricultural activities in mathematics learning is expected to introduce and preserve agricultural culture to students and learning becomes more fun and meaningful.
Designing HOTs-oriented learning material using PMRI approach
Authors: Septiani E , Aisyah N
Published: May 2020

This research aims to generate higher-order thinking skills (HOTs)-oriented learning trajectories that can help students to understand the material of two-variable linear equation using Indonesian realistic mathematics approach (PMRI). There are three stages in this research, namely preliminary design, learning experiments, and retrospective analysis. The subjects in this study are eighth grade students of SMPN 46 in Palembang. Data collection techniques use observation, interviews, video recordings, pre-test and post-test, and field notes.The results of this study is the development of Hypothetical Learning Trajectory into learning trajectory with 3 activities namely identifying problems and making examples, making mathematical models, and being able to solve problems in daily life.
Mathematical modeling teaching materials using hyperthermia context
Authors: Irwansyah E , Darmawijoyo
Published: May 2020

The purpose of this paper is to produce teaching materials for mathematical modeling in the context of hyperthermia for students of MTs Negeri 1 Lahat. This research uses design research with the type of development study that has two stages: preliminary and formative evaluation. The preliminary phase is carried out by making product modeling and evaluation teaching materials, data obtained by validating with experts. The success criteria of this study are to obtain valid teaching material, based on input from expert review and analyzing results from one-to-one stages. Based on the results of validation with experts and student answers at one-to-one. Needed, obtained valid modeling teaching materials.
Mathematical modeling worksheet using health context
Authors: Yusherlly H , Darmawijoyo
Published: May 2020

The purpose of this study is to produce a valid mathematical modeling student worksheet. The method in this study uses the design research method with the type of development study. The research instrument developed was a mathematical modeling student worksheet. The subject of this study were 11th grade of senior high school student at Tebing Tinggi. The results of this study were a valid mathematical modeling student worksheet
Students’ responses on ethnomathematics based learning with the context of Kayuagung community
Authors: Sari H J , Somakim  , Araiku J
Published: May 2020

This research belongs to the type of qualitative research with ethnographic design, which aims to find out the mathematical ideas contained in the innate ritual or the conveyance of the people of Kayuagung, Ogan Komering Ilir district called oban yadikon rasan. And to find out learning using the context of the oban yadikon rasan. The subjects in this study were resource persons who had knowledge about the wooden yadikon oban yadikon and IX grade students in SMP Negeri 2 Kayuagung. This research generates mathematical ideas to build dimensional space 3, which corresponds to junior high school students, namely the material to construct curved side spaces in class IX. After learning by using these mathematical ideas, students in class IX.1 as the subject of this study conclude that learning is more interesting and increases students’ interest in learning mathematics. Thus ethnomathemics-based learning with the context of oban yadikon rasan agung for junior high school students, received a positive response that is more interesting and increased student interest in learning.
Developing a learning design of mathematical modelling courses on understanding basic concept of mathematical modelling
Authors: Kurniadi E , Darmawijoyo  , Pratiwi W D
Published: May 2020

The approach to learning mathematical modelling is an approach that focuses on mathematics learning by using the context of real world phenomena so that the use of mathematics can be used in describing a process of understanding, simplifying, and solving problems in the form of mathematical modelling in order to have deeper understanding. Therefore, undergraduate students of the mathematics education as prospective mathematics teachers in schools need to get in-depth competencies related to mathematical modelling learning. These competencies were obtained by students in mathematics modelling courses. Based on the importance of mathematical modelling courses for students of mathematics education study programs need to be made in the design of learning in the subject of mathematical modelling based on the development of questions according to the characteristics of mathematical modelling. This study aims to generate local instruction theory in mathematics modelling courses after lectures are based on designing modelling task. Therefore this research will refer to design research methods in learning by constructing the Hypothetical Learning Trajectory (HLT) which will become Local Instruction Theory in the subject of mathematical modelling. In this paper, we focussed on the first step on HLT that is the basic concept of mathematical modelling. The results of this study are forming hypotheses, developing learning designs, and testing the truth according to research design methodology.
Secondary students’ higher-order thinking skills in solving PISA- like mathematical tasks
Authors: Meryansumayeka  , Putri R I I , Zulkardi  , Hiltrimartin C
Published: May 2020

Higher order thinking skills have become one of the main focuses in learning mathematics based on Indonesia curriculum currently. One of the teacher’s efforts to help students to develop higher order thinking skills is to provide questions like PISA questions. This is because PISA is a test of students’ abilities on an international scale, which also serves as a benchmark for the mathematical abilities of Indonesian students. This study is a descriptive type qualitative study. It purposed to describe students’ mathematical ability especially related to their higher order thinking skills in solving tasks like PISA tasks. Six secondary students consisting of 3 boys and 3 girls with different type of mathematical abilities were involved as research subject. Data were gathered through observation, interview, and documents such as students’ worksheets and they were analyzed qualitatively. The result showed that the most dominant skill appeared among analyzing, evaluating, and creating skills is analyzing skill. Although students sometimes made mistakes in determining final answers, they indicated trying to develop their skills by solving problem categorized as analyzing, evaluating or creating problem.
Analysis of student’s proof construction on logarithms
Authors: Jessica C , Hapizah  , Scristia
Published: May 2020

This research is a descriptive study that aims to describe the construction of student’s proof on logarithmic material. Proof construction is the ability to construct direct or indirect proof using information provided such as definitions, principles, theorems, and assumptions in a logical and detailed manner. The research subjects were 40 students of the X-grade students of MIA 6 in Palembang 10 Public High School. The learning process is carried out with direct learning steps. The data collection technique used is a written test consisting of 3 questions. The data obtained will be corrected, grouped and analysed using evaluation of proof consisting of five categories to identify students’ understanding of the construction of proof for each questions. The results of the study stated that the construction of proof by students on logarithmic material in the X-grade students of MIA 6 in Palembang 10 Public High School was already in the K1 category. This is due students are able to provide valid general arguments and use them to construction of proof.
Developing lesson plan and student worksheet on realistic mathematics approach oriented to achievement and interest in mathematics
Authors: Sukmaningthias N
Published: May 2020

This study aimed to produce lessons plan and student worksheet based on realistic mathematics approach oriented to the Achievement and Interest of mathematics learning which is good quality and fulfill valid, practical and effective criteria. This study was development research. The method used in this study was the development method of ADDIE. The ADDIE development method consists of analysis, design, development, implementation, and evaluation. The result of this study shows that the lessons plan and worksheet developed have been valid, the lesson plan is in very good quality with the average score 150.33, and the student worksheet is in good quality with the average score 117.67. The lessons plan and worksheet that have been developed is practical, with very good quality based on the teacher’s assessment and good quality by student assessment. The implementation of learning activity is 98%. The results also show that lessons plan and worksheet are effective. It is shown by the improvement of achievement and interest mathematics learning of students after using lesson plan and worksheet. Achievement has high quality with average score 82 and students learning completeness percentage reaches 82%. Similarly, the questionnaire results of interest are of high quality with the average score 88.71. Therefore, the lessons plan and worksheet fulfill the criteria of validity, practicality, and effectiveness.
Analysis of students’ mistakes in solving mathematics olympiad problems
Authors: Shinariko L J , Saputri N W , Hartono Y , Araiku J
Published: May 2020

This study aims at analysing students’ mistakes in solving mathematical olympiad problems. The test was conducted in SMA Negeri 1 Palembang involving 40 students. The main topics are algebra, combinatorics, geometry, and number theory. The analysis is based on Newman Error Analysis. The results show that the most common mistakes are found in combinatorics and geometry. The most common mistakes analysed using Newman Error are comprehension and transformation errors. In order to solve this problem, teachers need to assign various mathematical problems. Hence, the students will have more flexibility to apply problem-solving strategies.
High school students’ mathematical modeling skills in problem-based learning (PBL)
Authors: Sakinah A R , Hiltrimartin C , Hartono Y , Indaryanti
Published: May 2020

This study aims to know the mathematics modeling skill in Problem-based learning (PBL) in high school. Data were collected by test method in Students grade 10 SMA Negeri 2 in system of linear equation in three variable material. Based on the results of the research analysis, 64.7% of categorized learners have excellent modeling skills, 32.5% of the categories are good and 2% are poor. That is because students do not understand the problem, even though one of the goals of mathematics learning is students can solve mathematical problems which are covered by understanding problems and modeling problems into mathematical form. To realize these learning objectives the use of appropriate learning models is an important aspect. One learning model that can be used so that students have good modeling skill is Problem-based learning (PBL). PBL has a focus learning on contextual problems, so students can understand the problem and able to make mathematical models of the contextual problems presented.
High school student’s mathematical modeling skills in open-ended learning
Authors: Damayanti U , Hartono Y , Hiltrimartin C , Indaryanti
Published: May 2020

This research is a descriptive study aims to determine the mathematical modeling skills of students after using the open-ended learning to algebraic arithmetic operations in class VII SMP Negeri 17 Palembang. The subjects of this study were grade VII.6 students of SMP Negeri 17 Palembang with 32 students. The learning process is adapted to the stages of the open-ended learning. On the student worksheet, the problem given is an open-ended problem. The researcher also uses problem-solving questions during the evaluation test. Data collected using tests. The results of this study indicate that the mathematical modeling skill of students in open-ended learning in class VII.6 in SMP Negeri 17 Palembang is categorized good with an average of 78.54%. Students who are still lacking in modeling mathematical problems because they still incorrectly understand the problem and draw up a problem-solving plan.
Abstraction ability in number patterns problems
Authors: Adelia V , Susanti E , Sari N , Simarmata R H
Published: May 2020

This study aims to describe number patterns problems that are designed to measure the abstraction ability of junior high school students. This study was design research which consists: preliminary design, focus group discussion, trial, interview, and retrospective analysis. The instruments used in this study were test and interview to measure abstraction ability that has 5 indicators, which are: specialization, observation of pattern, generalization, conjecturing and testing conjecture. The subjects of this study were 3 students in grade 8 and the data analysis used in this study was qualitative. As a result of this study, the problem can be used to measure students’ abstraction ability.
Analysis of student’s thinking ability to solve higher-order thinking skills (HOTS) math problems
Authors: Megawati  , Hartatiana  , Wardani A K
Published: May 2020

This study aims to describe students’ thinking skills in solving mathematical problems which are Higher-order Thinking Skills (HOTS) problems. The thinking process used in this study refers to Bloom’s Taxonomy was modified by Anderson and Krathwohl. It was a qualitative descriptive study conducted at SMP Xaverius 1 in Palembang. There were 30 students of grade IX involved as subjects in this research. The data collection techniques used were tests, documentation, and interview. All students involved were given two HOTS questions. Based on the analysis of student answers and interviews, the results obtained stated that only 6.67% had reached the create stage in completing HOTS questions, the rest did not even reach the analysis stage.
Students’ statistical reasoning reviewed from academic internal factors in two learning classes
Authors: Cahyawati D , Wahyudin  , Prabawanto S
Published: May 2020

This paper presents the research results about the profile of students’ statistical reasoning ability (SRA) based on their academic internal factors, namely statistical prior knowledge (SPK), the intensity of study, and length of time to study. Data was collected from the seventy students of mathematics educations in a year of 2018/2019 that divided into two learning classes. One class was determined randomly as an experimental group and another class as a control group. The SRA and SPK achievements were measured by a written test. The aged of students ranged from 19 to 22 years. Based on gender, there were about 71% of females and 29% of males. The result of the study showed that the most answered about the intensity to study was “seldom”. They used the length of time to study for reviewing the statistics topic for about one to two hours. Both of the intensity to study and the length of time to study was not a significant effect on the difference of students’ SRA achievement between experimental and control groups. The difference in learning model was not the only one factor that significantly influenced the difference of students’ SRA achievement. The difference of the SPK factor produced the difference of the SRA achievement between experimental and control groups. Nevertheless, there was no interaction effect between the learning model and the level of SPK to the difference of the students’ SRA achievement.
Students’ mathematical reasoning in inquiry learning model
Authors: Helviyana G , Susanti E , Indaryanti  , Sari N , Simarmata R H
Published: May 2020

This research is a descriptive study that aims to identify student’s mathematical thinking in aspect reasoning on grade XI in topic sequences and series through the inquiry learning model. The test is consists of one problem. The subject for this research were 3 students of XI IPA 1 class at SMA Negeri 1 Indralaya Selatan. The learning process adjusted with the inquiry phases. The data collection techniques used in this research are written tests and interviews. The result of this study indicates that subject 1 (S1) appears inductive reasoning only on the perception of generality and expression of generality in which logical analysis is gathering facts, assessing or proposing assumptions, and setting conclusions. Subject 2 (S2) appears all indicators of inductive reasoning and indicators of logical analysis, and subject 3 (S3) appears all indicators of inductive reasoning while indicators of logical analysis are submitting assumptions, assessing or testing assumptions, and setting conclusions.
Analysis of student’s proof construction on matrix determinants
Authors: Sari D , Hapizah  , Scristia
Published: May 2020

This research is a descriptive qualitative research which aims to describe the construction of student evidence on the determinant matrix material. Construction of evidence is compiling evidence from a statement based on the definitions and rules used. The research subjects were students of class XI IPA Palembang 11 Public High School consisting of 42 people. The learning process takes place in accordance with the steps of direct learning. The data collection technique used is a written test consisting of three problem descriptions. The data collected was analyzed by evaluating the evidence from the results of student work consisting of four assessment categories as follows: valid arguments, proofs and proofs that were completed (K
1) valid arguments there were mathematical manipulation errors in the proof process (K
2), valid arguments but there are mathematical manipulation errors in the process of proof and proof of unfinished (K
3), empirical arguments, invalid or incomplete (K
4). Student proof construction in K
1 category was 34.52%, K
2 category was 16.67%, K
3 category was 22.62%, and K
4 category was 26.19%.
Students’ perception of reading and understanding mathematics textbook
Authors: Asri L , Oktalidiasari D , Darmawijoyo
Published: May 2020

This study aimed to describe the students’ perceptions of reading and understanding mathematics textbooks. This type of research is descriptive. Participant study consisted of 5 students in the sixth grade of Al-Fadh Islamic Elementary School Palembang. Data collection techniques in this research were questionnaire sheets to determine students’ stages in reading mathematics textbooks and students’ perceptions in understanding mathematics, and the interview was used to make sure their perceptions. Results of questionnaire sheets and interviews were analyzed based on stages of reading mathematics textbooks and students’ perceptions in understanding mathematics as follows: (1) Reading definitions or rules, (2) Reading example problems and (3) Doing problem exercises. Results showed that: The stages that are mostly done by Islamic elementary school students Al-Fahd in reading and understanding sixth grade mathematics textbooks are category 1, namely reading definitions or rules - learning example of problems - doing exercises about 3 students with a percentage 60% while category 2 is reading definitions or rules - learning example of problems - doing exercises for student with a percentage of 20% and category 3 that learning sample questions - doing one question exercise for a student with a percentage of 20%. As for students’ perceptions of understanding mathematics, the most is to understand examples of problems as many as 3 students with a percentage of 30%, understand the definition or rules of 1 student with a percentage of 20% and can do exercises about 1 student with a percentage of 20%.