bluuebunny/crossref_metadata_2025 huggingface dataset:
Tip-vortex flow characteristics investigation of a novel bird-like morphing discrete wing structure
Authors: Hui Zhe , Zhang Yang , Chen Gang
Published: March 2020

A bird-like morphing discrete wing, inspired by primary feathers of birds’ wings, was designed to control the wing-tip vortex strength. The influence of both the morphing process and discrete (non-continuous) surface feature for the bird-like wing structure on the tip-vortex flow characteristics was investigated in detail at Re = 87 000. The results reveal that the morphing process of the bird-like discrete wing structure can achieve the effective control of the core vortex strength by changing the flow structures around the tip-vortex core center(s). The induced drag yielded by the bird-like morphing wing structure is tightly related to its vorticity distribution in the near-wake region. Moreover, compared with the fully extended fixed-wing model with a continuous surface structure, the bird-like discrete wing model with the fully extended morphing state can suppress the core vortex strength by destroying the tip-vortex merging process. Meanwhile, the core vortex strength of the fully extended discrete wing model decays more sharply with the increase in x/c. The maximum proportions of the induced drag relative to the total drag for both the discrete and continuous wing models with the fully extended shape are 14.33% and 19.97%, respectively. However, the fully folding process of the bird-like wing structure significantly weakens the induced-drag reduction effect of the discrete surface structure. The maximum proportions of the induced drag relative to the total drag for both the discrete and continuous wing models with the fully folded shape are 17.59% and 18.41%, respectively.
Impacts of feeding zinc-methionine or chromium-methionine on performance, antioxidant status and physiological responses to transportation stress on lambs
Authors: Kaki Soumar Soheilla , Hozhabri Fardin , Moeini Mohammad Mehdi , Nikousefat Zahra
Published: March 2020

Context Road transportation of farm animals is an unavoidable activity in animal husbandry, which may lead to the stress. Metabolic modifiers, such as minerals, may be an effective strategy to improve the performance and immune system of animals. Aims The present study examined the effects of chromium-methionine (Cr-Met) and zinc-methionine (Zn-Met) supplementation on animal performance and response to transportation stress. Methods Eighteen lambs (18–20 weeks of age) were randomly assigned to the following three dietary treatments for 10 weeks: (1) basal diet (control, 0.021 g/kg Zn and 0.0001 g/kg Cr); (2) basal diet with addition of 10 Cr-Met mg/kg DM (containing 1 mg/kg Cr); and (3) basal diet with addition of 500 Zn-Met mg/kg DM (containing 50 mg/kg Zn). After a 6-week supplementation period, the lambs were transported by road for 3 h. Key results Mineral supplements did not affect final bodyweight, average daily gain or feed conversion ratio. The blood cortisol and aspartate aminotransferase concentrations were increased (P < 0.05) immediately after transportation (AT1) in all groups; however, they were lower in supplemented lambs than in the control (P < 0.05). Animals fed Cr-Met or Zn-Met diets had a higher albumin concentration at AT1 than did the control group (P < 0.05). Lambs on the Zn-Met diet showed a higher blood triiodothyronine and triiodothyronine to thyroxin ratio at AT1 and at 24 h after transportation (AT2) than did lambs receiving the control diet (P < 0.05). Lambs fed the Cr-Met diet had a lower blood malondialdehyde at AT1 and AT2 than did the control lambs (P < 0.05). Total antioxidant capacity (TAC) was higher in the Zn-Met-supplemented group than in other groups (P < 0.05). Supplementation with dietary Zn-Met increased serum TAC concentration in the kidney tissue compared with the control (P < 0.05), but had no effect on superoxide dismutase and glutathione peroxidase activities. The Cr-Met group showed also a lower malondialdehyde concentration (P < 0.05) and higher TAC, superoxide dismutase and glutathione peroxidase activities in the liver tissue (P < 0.05). Conclusions Dietary supplementation with 10 mg Cr-Met/kg (1 mg Cr) in comparison to 500 mg Zn-Met/kg (50 mg Zn) improved the stress response of lambs subjected to a short-time road transportation, whereas growth performance was not affected. Implications The administration of Cr-Met or Zn-Met to diet of lambs before transportation could reduce the adverse effects of road transportation stress.
Dietary lycopene alters the expression of antioxidant enzymes and modulates the blood lipid profile of pigs
Authors: Fachinello Marcelise Regina , Gasparino Eliane , Sturzenegger Partyka André Vinicius , de Souza Khatlab Angélica , Castilha Leandro Dalcin , Diaz Huepa Laura Marcela , Malavazi Ferreira Leonardo Felipe , Pozza Paulo Cesar
Published: March 2020

Lycopene has the highest antioxidant activity among carotenoids due to its high number of conjugated double bonds; thus, it can be used in pig diets to look for improvements in growth performance and health status, eliminating or preventing the formation of free radicals. Therefore, the aim of the present study was to investigate the effects of dietary lycopene on the growth performance, the gene expression of antioxidant enzymes and blood lipid profile of finishing pigs. In total, 40 barrows and 40 gilts (Piétrain × Landrace × Large White) were used, averaging 75.04 ± 1.6 kg of initial bodyweight. Pigs were distributed in a 2 × 5 factorial arrangement, consisting of two genders (male and female) and five dietary levels of lycopene (0, 12.5, 25.0, 37.5 and 50.0 mg/kg of diet) supplemented for 28 days. It was observed that gilts presented with average daily feed intake (P = 0.001) being lower and the gain:feed ratio (P = 0.001) higher than for barrows. Increasing dietary lycopene concentration provided a linear decrease in the gene expression of the enzymes superoxide dismutase (SOD1; P = 0.018) and catalase (P = 0.001) in the liver of gilts. The gilts showed a lower gene expression than did barrows for SOD1 gene (P = 0.001) receiving 50.0 mg lycopene/kg of diet and for catalase gene (P = 0.001) receiving of 0, 12.5 and 50.0 mg lycopene/kg of diet. Glutathione peroxidase showed a lower expression (P = 0.001) for gilts than for barrows. Total cholesterol, low-density lipoprotein (LDL) and LDL:high-density lipoprotein (HDL) ratio decreased (P = 0.001) as lycopene concentration increased in the diet. Increasing dietary lycopene in pig diets improved the lipid profile of the blood plasma, providing an increase in the concentration of high-density lipoprotein (HDL; P = 0.001). Gilts had greater plasma concentrations of urea (P = 0.001) and triglycerides (P = 0.001) and lower concentrations of HDL (P = 0.001), LDL (P = 0.001) and a lower LDL:HDL ratio (P = 0.004) than did barrows. Dietary lycopene up to 50 mg/kg does not affect the growth performance of pigs, acting as a potent modulator of the lipid profile and also reducing the plasma concentrations of total cholesterol and low-density lipoproteins, while increasing the high-density lipoproteins. In addition, lycopene also reduces the gene expression of superoxide dismutase and catalase enzymes in the liver of gilts.
Linseed and glycerol in forage diets effect methane production and rumen fermentation parameters in a Rusitec semi-continuos system
Authors: Gutierrez-Gomez Constanza , Vera Nelson , Allende Rodrigo , Williams Pamela , Astudillo Rita , Ávila-Stagno Jorge
Published: March 2020

Context
The use of oilseeds as a feed ingredient has been proposed to improve fatty acid profiles and reduce methane (CH4) emissions. Glycerol has been used as a common additive in ruminant feeding systems with variable effects on CH4 production. The effects of the combination of these ingredients remain unknown.

Aims
The aim of this study was to assess the effects of feeding linseed and increasing concentrations of glycerol in forage diets supplemented with corn grain on nutrient disappearance, CH4 production and rumen fermentation parameters.

Methods
Experimental diets were: control (70:30% hay:corn); linseed (70:15 :15% hay:corn:linseed); 5% glycerol (70:10:15:5% hay:corn:linseed:glycerol); 10% glycerol (70:5:15:10% hay:corn:linseed:glycerol). Diets were incubated in a completely randomised design with four replicates per treatment in a Rusitec apparatus for 15 days (10 days adaptation, 5 days sampling).

Key results
Total VFA production (VFA, mmol/day) was quadratically increased due to glycerol concentration in the diets (P = 0.009). Acetate:propionate (A:P) decreased by the inclusion of linseed (P < 0.001) and glycerol into the diets (P < 0.001). Linseed inclusion in the diet reduced CH4 production, mg/DM disappeared (P = 0.004) by up to 36%. These effects were not altered by the addition of glycerol into the diets. Ammonia nitrogen (NH3-N) production increased 2-fold in the linseed-added diets, but this effect was partially reverted by increasing glycerol concentrations in the diets (P < 0.001). Crude protein (CP) disappearance increased (P < 0.001) in the linseed added diets, with no effect of glycerol addition. Neutral detergent fibre (aNDFom; P = 0.005) disappearance was increased by the addition of linseed to the diet.

Conclusions
The use of linseed in ruminant diets reduces CH4 emissions but increases NH3-N production in a Rusitec system. This latter effect is partially reverted by glycerol inclusion in the diet. Propionate production increases with the inclusion of glycerol, but does not alter CH4 production. Including linseed increases the in vitro CP disappearance without affecting DM total disappearance.

Implications
Care should be taken with the use of oilseeds in ruminant diets as it can reduce CH4 emissions but may cause important increases in NH3 emissions. Inclusion of glycerol may partially overcome this latter issue.
Post-weaning growth rate effects on body composition of Nellore bulls
Authors: Silva Luiz H. P. , Paulino Pedro V. R. , Benedeti Pedro D. B. , Estrada Mauricio M. , Alves Lyvian C. , Assis Débora E. F. , Assis Gutierrez J. F. , Leonel Fernando P. , Valadares Filho Sebastião C. , Paulino Mário F. , Chizzotti Mario L.
Published: March 2020

Context
Previously feed-restricted cattle may exhibit compensatory growth during the finishing phase. However, the efficiency in converting feed into carcass should be evaluated since cattle undergoing compensatory growth usually have high non-carcass weight gain.

Aims
The objective of this study was to evaluate the effect of growth rate throughout the post-weaning growing phase on subsequent feed efficiency, carcass gain, and gain composition.

Methods
Thirty-nine weaned young Nellore bulls averaging 230.4 ± 5.62 kg of bodyweight and 8.5 ± 0.25 months of age were used. Initially, five bulls were slaughtered as a reference initial group. The remaining bulls were randomly assigned to one of three nutritional plans to achieve Low (0 kg/day), Medium (0.6 kg/day) or High (1.2 kg/day) average daily gain (ADG) throughout the post-weaning growing phase, followed by high growth rate during the finishing phase. One-half of the bulls from each treatment were slaughtered at the end of the post-weaning growing phase, and the other one-half after the finishing phase. During both phases the feed intake, apparent digestibility, performance, and body composition were evaluated.

Key results
Throughout the post-weaning growing phase, High bulls had greater ADG and more efficiently converted feed into carcass, compared with other nutritional plans (P < 0.01). Throughout the finishing phase, Low bulls had greater ADG, carcass gain, and feed efficiency than High and Medium bulls (P < 0.01). Previous feed restriction did not affect (P > 0.05) apparent digestibility. During the finishing phase, previously restricted bulls fully compensated for the lost visceral organ weight, whereas the losses of bodyweight and carcass weight were only partially compensated. Throughout finishing, Low bulls had the greatest feed efficiency and profitability among nutritional plans. However, considering the overall experiment, Hight bulls converted feed into carcass more efficiently than Low bulls (P = 0.02), but did not differ from Medium (P > 0.05).

Conclusions
Although previously restricted bulls had greater performance and efficiency throughout finishing, the improvement was not enough to reach the same carcass weight at the same age of the unrestricted bulls.

Implications
Despite the greater profitability of previously restricted bulls throughout finishing, unrestricted bulls were more profitable considering both growing and finishing phases.
Phenotypic variation across populations of red mullet (Mullus barbatus) in different environments of the central Mediterranean
Authors: Quattrocchi Federico , D'Anna Giovanni , Fiorentino Fabio , Titone Antonino , Zenone Arturo , Garofalo Germana
Published: March 2020

Geometric morphometrics is an effective tool for quantifying intraspecific variations in fish body shape and differentiating populations and fisheries stocks. This study used geometric morphometrics to examine patterns of intraspecific morphological differentiation among four red mullet (Mullus barbatus) populations in the Strait of Sicily in the central Mediterranean Sea. We hypothesised that morphological differences among local populations were caused by the diverse hydrodynamic features characterising the sampled areas and maintained by geographical isolation. We also examined whether body shape homogeneity or variability within local populations was related to seabed rugosity as an indicator of habitat complexity. We found that the morphological divergence between local populations was constrained by geographical proximity. Populations varied primarily in body depth, with more elongate specimens inhabiting hydrodynamic areas. In addition, site-specific homogeneity in body shape was positively related to seabed rugosity, so that in more structurally complex habitats body shape was less morphologically variable. An improved understanding of the spatial structure of red mullet populations in the Strait of Sicily is needed to better define the boundaries of natural populations.
‘We don’t want to drink that water’: cross-cultural indicators of billabong water quality in remote Indigenous Australia
Authors: Russell Shaina , Ens Emilie , Ngukurr Yangbala Rangers
Published: March 2020

Globally, many Indigenous people rely on surface waters for drinking due to limited access to safe or palatable water, cultural and spiritual reasons and belief in its healing properties. In northern Australia, Indigenous people from the remote community Ngukurr have raised concerns about drinking water from freshwater billabongs due to potential microbial contamination from feral ungulates (buffalo, pig, horse and cattle). In response to these concerns, a cross-cultural assessment of water quality and drinking water safety was undertaken. Indigenous biocultural indicators of water quality and perceptions of drinking water safety at billabongs were documented. In addition, Western scientific methods were used to assess billabong waters surrounding the Ngukurr community for the waterborne pathogens Cryptosporidium and Giardia. The results revealed that local Indigenous people make decisions about water quality and drinking water safety through visual indicators, seasonal knowledge and intuition. Giardia was only detected in the late dry season and Cryptosporidium was not detected during either the wet or dry season. The commonly held Indigenous perspective aligned with the pathogen results, whereby billabongs were safer to drink from in the early dry season then the late dry season. Boiling water when drinking from billabongs during all seasons is considered best practice to avoid ingestion of infective enteric pathogens.
What do young women living in regional and rural Victoria say about chlamydia testing? A qualitative study
Authors: Wagg Emma , Hocking Jane , Tomnay Jane
Published: March 2020

Background
Chlamydia trachomatis is the most commonly notified sexually transmissible infection in Australia, with almost 100000 cases diagnosed in 2018. Chlamydia is easy to diagnose and treat, but infections are underdiagnosed. Eighty per cent of chlamydia cases are asymptomatic. Without testing, infections will remain undetected. Several barriers to testing have been identified in previous research, including cost, privacy concerns for young rural people, knowledge gaps, embarrassment and stigma. The aim of this study was to investigate young regional and rural women’s understanding of chlamydia and factors that may prevent or delay testing. Methods: Semistructured interviews were conducted with 11 women aged between 18 and 30 years residing in north-east Victoria, Australia. Interviews were transcribed verbatim and analysed thematically. Results: Themes were grouped under four categories: (1) chlamydia and stigma; (2) the application of stigma to self and others; (3) factors affecting testing; and (4) knowledge. A chlamydia infection was associated with stigma. The young women in this study anticipated self-stigma in relation to a positive diagnosis, but resisted stigmatising others. Increased knowledge about chlamydia prevalence was associated with reduced self-stigma. The most consistent factor affecting testing decisions was personal risk assessment. Knowledge gaps about symptoms, testing and treatment were also identified, with participants not always accessing information from reputable sources. Conclusion: Chlamydia testing was viewed as a positive activity among this cohort. However, there is considerable perceived stigma about being diagnosed with an infection. Interventions that communicate prevalence, reduce stigma and provide factual information about testing and risk are still needed. Clinicians have an opportunity to convey this information at consultation. Health promotion workers should continue to develop and run campaigns at a community level to encourage regular screening.
Possibility and necessity and the scope of negation in Early Middle Chinese
Authors: Meisterernst Barbara
Published: March 2020

This paper provides a classification of modal verbs of possibility and necessity in Late Archaic and Early Middle Chinese based on an analysis of their scopal features with respect to negation. It shows that circumstantial readings and deontic readings are interpreted in two different syntactic positions which can be determined by the scope of negation following the cartographic approach proposed in Tsai (2008,2015) and the proposal ofCormack and Smith (2002)of a Polarity Head, which constitutes a syntactic divide of the domain of necessity modals from the domain of circumstantial modals. Our analysis of the scope of negation demonstrates that the deontic interpretation of possibility modals requires their upward movement from the lexical to the functional domain as part of the grammaticalization process from pre-modal lexical verbs to modal auxiliaries of different functions in Modern Mandarin. In Early Middle Chinese, negated modal verbs of possibility start to replace the synthetic modal negators of Archaic Chinese as part of the general process of analyticization of Chinese. We also show that the only true necessity modals in Late Archaic Chinese belong to the category of circumstantial modals due to their scopal features when they are negated.
An analysis of focus and its role in the answering systems of polar questions in Chinese and English
Authors: Liou Mei-Ling Teresa , Liu Chen-Sheng Luther
Published: March 2020

Instead of classifying natural languages in terms of their answering systems for polar questions, this study investigates how languages construct the answering system for the polar questions with a special concentration on the answering system of the Chinesemaparticle question and English polar questions. We argue that the primarily mechanism that natural languages adopt to construct an answering system is the focus mechanism which is based on the relationship between a focus sensitive marker and its association of focus. The different answering patterns to polar questions result from different scopes of focus. In a polar question, what is being focused by the focus sensitive marker or focus operator falls into question scope (focus association). The respondent answers the polar question based on the proposition in the question scope. Answering with a positive particle expresses agreement with that question proposition while answering with a negative particle conveys that the question proposition is not true.
County-Level Factors Underlying Opioid Mortality in the United States
Authors: Langabeer James R. , Chambers Kimberly A. , Cardenas-Turanzas Marylou , Champagne-Langabeer Tiffany
Published: March 2020

Background

Mortality from overdoses involving opioids in the United States (U.S.) has reached epidemic proportions. More research is needed to examine the underlying factors contributing to opioid-related mortality regionally. This study's objective was to identify and examine the county-level factors most closely associated with opioid-related overdose deaths across all counties in the U.S.

Methods

Using a national cross-sectional ecological study design, we analyzed the relationships between 17 county-level characteristics in four categories (i.e. socio-economic, availability of medical care, health-related concerns, and demographics) with opioid mortality. Data were extracted from the Robert Wood Johnson County Health Rankings aggregate database and Centers for Disease Control and Prevention (CDC)'s Wide-ranging Online Data for Epidemiological Research (WONDER) system.

Results

There were 1058 counties (33.67% of 3142 nationally) with reported opioid-related fatalities. Median opioid-related mortality was 15.61 per 100,000 persons. Multivariate regression results indicate that counties with the highest opioid-related mortality had increased rates of tobacco use, HIV, Non-Hispanic Caucasians, and females and were rural areas, but lower rates of food insecurity and uninsured adults. The rates of tobacco use and HIV had the strongest association with mortality. Availability of either mental health or primary care providers were not significantly associated with mortality. Severe housing problems, high school graduation rate, obesity, violent crime, and median household income also did not contribute to county-level differences in overdose mortality.

Conclusions

Future health policies should fund further investigations and ultimately address the most influential and significant underlying county-level factors associated with opioid-related mortality.
Biomaterial-based strategies to prime dendritic cell-mediated anti-cancer immune responses
Authors: Park Wooram , Song Kwang Hoon , Lim Jaesung , Park Chun Gwon , Doh Junsang , Han Dong Keun
Published: March 2020

Cancer immunotherapy has been extremely successful in curing patients over the last decade. Immune checkpoint blockades (ICBs) that unleash the brakes in T-cells to promote cytotoxicity against cancer cells are the most successful forms of cancer immunotherapy, yet therapeutic efficacy needs to be improved as only a fraction of patients responds. Dendritic cells (DCs) are immune cells that prime immune responses by collecting information in tumour tissues, and carrying that information to T-cells, thus delivering proper information to DCs is essential. Biomaterial-based approaches can be powerful tools for this purpose, as biomaterials allow us to deliver a variety of immunotherapeutic agents at the right time and place. Herein, we review the key concepts of cancer immunotherapy; discuss the principles for designing biomaterials to deliver immunomodulatory molecules; and outline biomaterial-based strategies to prime anti-cancer immune responses. Specifically, we focus on two widely used forms of biomaterials, multifunctional nanoparticles and biocompatible scaffolds.
Bouncing a ball at rest on a surface
Authors: Cross Rod
Published: March 2020

A ball at rest on a surface can be made to bounce up by pushing it down then
releasing the downward force as fast as possible. Measurements and calculations
are presented to show how it can best be done.
Enhanced energy confinement after series of pellets in Wendelstein 7-X
Authors: Baldzuhn J , Damm H , Beidler C D , McCarthy K , Panadero N , Biedermann C , Bozhenkov S A , Dinklage A , Brunner K J , Fuchert G , Kazakov Y , Beurskens M , Dibon M , Geiger J , Grulke O , Höfel U , Klinger T , Köchl F , Knauer J , Kocsis G , Kornejew P , Lang P T , Langenberg A , Laqua H , Pablant N A , Pasch E , Pedersen T S , Ploeckl B , Rahbarnia K , Schlisio G , Scott E R , Stange T , Von Stechow A , Szepesi T , Turkin Y , Wagner F , Winters V , Wurden G , Zhang D.
Published: March 2020

A series of ice pellets was injected into the advanced stellarator Wendelstein 7-X (W7-X). Although the pellets were small and slow, deep and efficient particle fueling could be observed experimentally. The most striking feature appearing after the injection of the pellets, however, was a transient increase in the energy confinement time. This transient phase resembled in several aspects modes of enhanced confinement after gas-puff or pellet injection, as observed in other fusion experiments. All experimental attempts, to prolong this phase, failed. In this paper, discharges are described that show the enhanced energy confinement, and some conditions are summarized which seem to be essential in order to generate it. The focus here is on deep particle fueling by pellets, and shaping of the density profiles during and after the series of pellets. During this time, neutral gas particle re-fueling at the plasma edge is reduced, while density profile peaking and low impurity radiation losses are present.
The effect of variation in the amount of Hemicellulose from Corn Cobs (Zea mays L) and pH on Metronidazole Microparticle Release
Authors: Dalimunthe Gabena Indrayani , Muchlisyam  , Harahap Urip , Nasution Azizah
Published: March 2020

The present study was conducted to investigate the percentage of metronidazole microparticle release in an acidic environment at pH 1.2 and an alkaline environment at pH 7.4 and pH 8 in which the highest release occurred and to investigate the microparticle release kinetics. Method: The research method used was an experimental method by making metronidazole microparticles with variations in the amount of hemicellulose from corn cobs which were combined with sodium tripolyphosphate (STPP) and propylene glycol (PG). The mixture was then put into capsules made from a combination of hemicellulose and sodium alginate (3:1). Results: Formula IV provided the smallest percentage of release in the gastric medium at pH 1.2 which was in the 240th minute with 1.80 ± 0.06 percent, followed with the formula IV in the intestinal medium at pH 7.4 in the 600th minute with (3.14 ± 0.13) percent. The largest release in formula IV was found in the colon medium at pH 8 which was in the 600th minute (66.21 ± 0.82) percent. The metronidazole microparticle formula using 200 mg of hemicellulose was not significantly different from using 250 mg of hemicellulose. The metronidazole microparticle release kinetics were formulated using 50, 100, 150, 200, and 250 mg of hemicellulose, all of which followed the zero order, first order, and the Higuchi order release kinetics. Conclusion: The release kinetics of metronidazole available on the market showed greater results than the metronidazole microparticles release which was formulated with variations in the amount of hemicellulose in various mediums.
Design of a Problem-Based Virtual Learning Environment
Authors: Mukhtar  , Mulyono  , Daulay K R , Siregar E
Published: March 2020

This study aims to develop a problem-based virtual learning environment with interactive scaffolding for junior high school mathematics learning. Although several virtual learning environments for problem-based learning have been developed in response to developments in information and communication technology and the need for innovation in learning, the inclusion of interactive scaffolding as external support needed by students during the problem-solving process still has not received special attention. The development in this research follows the stages of ADDIE: Analysis, Design, Development, Implementation, and Evaluation. Research results are still limited to the design stage.
Pineapple callus induction from Sipahutar North Sumatera Indonesia (Ananas comosus L.) with bud as a source explant
Authors: Harahap F , Djulia E , Purnama D , Nusyirwan  , Altio V , Rahayu S , Rosmayati  , Poerwanto R , Hasibuan R F M
Published: March 2020

The preservation and development of Sipahutar pineapple is very important to do. One of the most effective ways is with tissue culture techniques. The aim of this research is to know the effect of 2,4-Diclorofenoxyacetic acid (2,4-D), kinetin, and interaction of both Plant Growth Regulator (PGR) to callus induction on pineapple (Ananas comosus L.) from Sipahutar Sumatera Utara Indonesia. The design of this study used a Factorial Completely Randomized Design, namely is 2.4-D with 3 doses of treatment (0, 1, 2 ppm) as the first and the second factor of kinetin with 3 doses (0, 0.5, 1 ppm). The observation process was conducted for 28 days and 35 days after induction. The parameters observed were the formation time of callus, callus color, callus biomass, and the height of callus pile. The results showed that 2,4-D, kinetin and interaction of 2,4-D and kinetin significantly influenced the time of callus formation, callus biomass, and significant effect on the height of callus pile. The time of callus formation is the fastest on day 8 after induction. The best of callus color is whitish green comes from 2,4-D 0 ppm and kinetin 1 ppm treatment. The highest biomass is 1.69 grams. The highest stack height of callus was 2.32 cm. The highest biomass, stack height, surface area of callus derived from the treatment of 2,4-D 0 ppm and kinetin 0 ppm.
The analysis of students’ learning difficulties on the structure and function of animal tissue topic in second grade (science) in senior high school
Authors: Simatupang Z , Manik M C
Published: March 2020

The objectives of this study are to know the level of students’ learning difficulty on the structure and function of animal tissue topics based on the indicator and cognitive aspects and also identify the factor influences it could happen. This descriptive research conducted in SMA Negeri 1 Perbaungan and all second-grade students are the research population. They grouped into four classes and using a purposive sampling method, 50 students from each class who have difficulty on this topic taken as samples. The data were analyzed both in qualitative and quantitative ways. The multiple-choice test with 30 questions used to identify the student’s ability on the topic. For influencing factors, an interview and a closed typed questionnaire employed to collect the data. The study revealed that the student’s ability was less than the minimum score means that the student experienced difficulty on this topic. The difficulty based on cognitive and indicator found at a moderate to a high level. Furthermore, the factors that influenced learning difficulty were seven factors included learning habits, motivation, teacher, and learning activity. These factors influenced at a moderate level, while learning source, interest, and the nature of the topic influenced at a high level.
Developing of student worksheets with scientific approach on growth and development topic at SMAN 1 berastagi grade XII academic year 2019/2020
Authors: Sitanggang I , Gultom E S
Published: March 2020

This research aims to design and produce Student Worksheets based on scientific approach on Growth and Development topic. The research design used is Research and Development method with 3D model which is define, design and developing stage. The subjects of this research were Material Expert, Learning Expert, Biology Teacher, and Students of grade XII SMAN 1 Berastagi that consist of 6 classes with 216 students as population sample number. Data collection was carried out with instrument in the form of questionnaire, while the data analysis using qualitative and quantitative descriptive analysis. The result showed this product classified into very feasible category with an average score 95,93% by material and learning experts assesment, meanwhile the assessment of biology teacher obtained 95% with very good category as well. The student responses of the small group, limited group, and large group trials obtained very good category with the whole average score 91,66 %. This student worksheets obtains “Very Feasible” criteria and has fulfilled the requirements of eligibility for use as a medium of biology learning process.
The Development of Trigonometry E-Modules For Senior High School Using Differentiated Instruction (DI) Approach
Authors: Mardiyah  , Johar R , Mailizar
Published: March 2020

This research aimed to develop trigonometry e-module for senior high schools through Differentiated Instruction (DI) approach based on Moodle. The method used in this research were Research and Development using Plomp model (2013), consisted of the stages of preliminary research, prototyping, and assessment. This research only discussed research results of the first two stages. Preliminary research stage was the analyzing step that included the curriculum, the students’ characteristics, and learning materials analyses. The instruments used in this stage were the need analysis sheet, the observation sheet and the interview guidelines. The research subjects in the first stage were the principal, two Year 11 mathematics teachers and five Year 11 mathematics and science students selected randomly. The next stage was prototyping, where the researcher administered the validation sheet to five students. The result of preliminary stages showed that mathematics teachers have already used the curriculum 2013, and both students and teachers needed an interesting learning media. The validation result of the prototyping stages showed that the module developed was valid and practical. The subsequent stage will be testing the module.
The Improving of Mathematical Understanding Ability and Positive Attitudes of Unimed FMIPA Students by Using the Contextual Teaching Learning (CTL)Approach
Authors: Purba G I D , Surya E
Published: March 2020

The active involvement of students in learning must be supported by providing special activities that are student-centered so that they can do "doing math" to find and build mathematics facilitated by lecturers. One aspect of "doing math" is to improve mathematical communication skills. The existence of communication skills will certainly bring students to a deep mathematical understanding of mathematical concepts. In addition to mathematical communication skills, an attitude that must be possessed by students is needed, including appreciating the beauty of mathematics, having high curiosity and learning mathematics. With such an attitude, students are expected to develop mathematical abilities, use mathematics to solve problems faced in their lives, and can develop mathematical dispositions. This research conducted on students of FMIPA with the aim of: (1) knowing students’ mathematical communication skills taught by using the problem based learning model and talking learning model; (2) knowing the differences in students’ mathematical disposition abilities taught using Problem Based Learning model and talking learning model; (3) produce a mathematical learning device in the form of an appropriate LAS used to improve students’ mathematical communication; (4) produce teaching materials in the form of textbooks with appropriate problem-based learning model used to improve students’ mathematical communication.
Learning media Animations for Subjects Evaluation and Chemistry Learning Outcomes
Authors: Sugiharti Gulmah , Dalimunthe Makharany , Syuhada Feri Andi
Published: March 2020

Availability of learning media Subjects Evaluation and Chemistry Learning Outcomes is still very limited. In this research, the development of macromedia flash-based animation media will be carried out, the purpose of this study is to: (1) developing macromedia flash-based animation media in the Course of evaluation. (2) validating and revising animation media based on macromedia flash in the Evaluation course, which in the next research will be tested on the developed media in the field.This research is a research and development (research and development). Where the product developed in this research is animation media based on macromedia flash in the Subject ofEvaluation and Chemistry Learning Outcomes. The population and sample of this study, namely teaching materials for making animation media, lecturers and students as validators. To obtain research data, a validation rubric is used in the form of responses and suggestions for improvement from the validator.The data analysis technique was calculated using percent feasibility and suggestions for improvement from lecturers and validators. The results showed that the developed animation media was feasible with a feasibility value of 80%, and the results of student responses were obtained at 82% with excellent criteria.This research produces macromedia flash-based animation media that can be used in the Chemistry Evaluation and Evaluation learning outcomes which are then expected to improve student learning outcomes
Development of Teaching Materials Integrated Spiritual Value Assisted by Visual Studio Media with Problem Based Learning Model In Terms of Learning Motivation
Authors: Oktavianti D , Darmana A , Sudrajat A
Published: March 2020

This study aims to determine the effect of learning motivation on learning outcomes taught by chemistry teaching materials integrated spiritual value using the problem-based learning model assisted by visual studio media. This research used the method of research and development. Instruments used a questionnaire of learning motivation and multiple choice. Based on the analysis of the learning outcome, it is obtained 0.004<alpha (0.05) a sig.score, while the analysis of learning motivation is obtained 0.003<alpha (0.05) a sig.score. This research can be concluded that there is a positive correlation between learning motivation and learning outcome based on Pearson correlation test minimum category as many as 0.325.
The Effect of Red Dragon Fruit Juice Towards Cholesterol Level and Maximum Aerobic Capacity (VO2max) on Sport Science Students Treated with Heavy Physical Exercise
Authors: Harahap N S , Sunarno A , Simatupang N , Suprayitno
Published: March 2020

Heavy physical exercise causes increased production of free radicals. The accumulation of oxidative stress can reduce cardiorespiratory endurance. VO2max plays a role as an indicator of the circumstances of cardiorespiratory. An increase in cholesterol levels is a risk factor for coronary heart disease. As a result, there is a decrease in fitness marked by a decrease in the value of VO2max. The purpose of this study was to determine whether the antioxidant supplement given during heavy physical exercise had a beneficial effect on decrease cholesterol and the increase of VO2max levels. The subjects were 30 students, male sex, 20-22 years old, divided into 3 groups randomly, each 10 people, group 1: subjects not given heavy physical exercise and only given a placebo (control); group 2: subjects given heavy physical exercise and placebo (HPE-RDF); group 3: subjects given heavy physical exercise and red dragon fruit juice (HPE+RDF). Measurement of cholesterol and VO2max levels in the pre-test and post-test. The results showed that there was an increase in VO2max and a decrease in cholesterol (p<0.05) in the HPE + RDF group compared to the HPE-RDF group. The Heavy exercise group given red dragon fruit juice can increase VO2max and reduce cholesterol levels.
Blog as a Learning Media in Increasing Student Understanding
Authors: Siregar TM , Frisnoiry S , Andreani A
Published: March 2020

This study aims to determine the effect of blogs as a learning medium on increasing student learning outcomes in the Mathematics Learning Evaluation course. This research was conducted in two classes, each as a control class and an experimental class. The method used is a quasi-experimental design with the Experimental Randomized Control Group. The instruments used to collect data in this research were objective tests and questionnaires. This study concluded that there were differences in learning outcomes between students who were taught using blog media and students who were taught without using blog media. And the response of students to the media blog is good.
Analisys of the impact of mathematical learning with geogebra asistance on critical thinking ability
Authors: Munandar  , Usman  , Saminan
Published: March 2020

This study aimed to analyze the impact of mathematics learning assisted by geogebra software on students’ critical thinking skills. This research was an experimental research with a quantitative approach. There were two groups of samples used, namely the experimental group with learning assisted by geogebra software, and the control group with learning without using geogebra software. The population in this study were students of class VIII Junior High School 2 Banda Aceh with students of class VIII-2 as an experimental class and VIII-8 as a control class. The instruments used were pre-test and post-test critical thinking skills. Data analysis techniques using non-parametric statistics with Mann-Witney test and analyzed with SPSS statistics 22 software. The results showed that mathematics learning assisted by geogebra software has an impact on increasing students’ critical thinking skills.
Finite Markov Chain in Inventory Control
Authors: Sinaga M S , Purba O , Nasution H
Published: March 2020

In this paper we present an introduction to the finite markov chain. Transition probabilities are calculated, as well as a transition probability matrix. We present the necessary fundamentals of probability theory on markov chains for stochastic processes and stochastic modelling in inventory control.
Estimates Long-term Data of Multi-State Model
Authors: Manullang S , Hutabarat H D M , Panjaitan M
Published: March 2020

This study aims to obtain an estimate of transition opportunities from the health status of elderly persons. The phenomenon of changes in health status in the elderly has a chance of transition at each shift in their health status. To obtain an accurate estimate of the transition probability in a multi-status model of health status is indispensable. We estimate the four-state multi-state models from alive/healthy through out-patient sickness, in-patient sickness to death with recovery from either of the two cases of sickness will be used based on medical data elderly. The focus will be on deriving the probabilities of transition from one state to another via the forces of intensities. We then provide a method for estimating unique transition probabilities for both males and females elderly, generally behaved as expected with transition probabilities to sickness states increasing with age. Transition probabilities out of the sick state appear higher for males than females.
Optimization and Assessment Orally Disintegrating Tablet of Using Biopolymer Combination
Authors: Ridwanto  , Lubis M S
Published: March 2020

Orally Disintegrating Tablet (ODT) or a crushed tablet in the mouth is one of the most useful drug preparations for geriatric and pediatric patients who have difficulty swallowing conventional tablets. This research aims to determine the effect of single and combination biopolymers. The optimization of the disintegration time of ODT preparations did by 11 formulas printed with direct press technique. It consisted of single biopolymers and combinations of Chitosan, Xanthan gum, Carboxymethyl cellulose, and Maltodextrin. Evaluation of ODT preparations begins with an evaluation of formulation, which includes the flow rate test, fixed angle, and compressibility index. The evaluation of the formulated ODT measured by size and weight uniformity test, hardness test, rigidity test, and wetting time test. Also, in vitro and vivo disintegration test. All formulas meet the ODT physical quality requirements. ODT 8 is an ODT formula that uses a disintegrant combination of biopolymer Chitosan and Maltodextrin. It shows the fastest disintegration time is 19 seconds. The statistical test showed a significant difference between the ODT formula to the optimization of disintegration time with a value of p < 0,05. ODT with a biopolymer combination has a faster disintegration than ODT with a single biopolymer.
Vegetation Structure and Composition in Taman Wisata Alam (TWA) Sicike-cike as Ritual Site for Local Community
Authors: Huda M K , Pasaribu N , Syamsuardi  , Siregar E S
Published: March 2020

Taman Wisata Alam Sicike-cike is a nature conservation area intended for the benefit of natural tourism and recreation. TWA Sicike-cike besides being used as tourist site, is also known for its ritual or traditional ceremonial site performed by the Pakpak-Dairi tribe. Presence of local wisdom on forest management, such as tapping the sap of incense (Styrax paralleloneuron) and floral organ are commonly utilized as a worship material during traditional rituals. The importance of this forest region for local communities is crucial for the sustainability of the local wisdom of the Pakpak-Dairi tribe. This study aims to determine the vegetation structure and composition in ceremonial sites located within TWA Sicike-cike. The study used vegetational analysis to obtain Importance Value Index (IVI) from each structures (seedling, sappling, pole and tree. The results showed that the largest INP at seedling to tree structure was dominated by Rhododendron malayanum with 46.29, 26.41, 55.53, and 28.99 for seedling, sapling, pole and tree, respectively. Shannon’s diversity index (H’) in this region falls between medium to high diversity categories. Hence, Rhododendron malayanum is considered as primary indicator of typical vegetation in ceremonial site of TWA Sicike-cike which dominate all types of vegetational structure with complete growth rate.
Implementation of Dubido Based on Contextual in Improving Students Achievement on Rate Reaction
Authors: Muchtar Z , Rosalia A V A , Silaban S
Published: March 2020

In recent year, efforts to develop learning media for various learning models continue to be the center of attention of education stakeholders. This is caused not only because it is facilitated by information technology but there is a change in the lifestyle of students due to the presence of information and communication technology. In this research, the development of android-based mobile education (Dubido) is based on contextual learning for reaction rate material. Research which is an R&D research with the aim of improving student learning outcomes and interests. The sample of this research were undergraduates’ students from chemistry education study program. The sample was divided into two classes where the experimental class 1 was taught using dubido based on contextual while the second experimental class was taught by direct instruction. The results showed that the media of dubido that had been developed increased the interest of students studying the material reaction rates. And the implementation of dubido based on contextual was given positive effect to increase student’s achievement.