Analisis Keaktifan Belajar Siswa Selama Pembelajaran Daring pada Masa Covid-19

The purpose of this study is to determine the activity of online learning during the covid-19 period and to find out the efforts made in overcoming obstacles to online learning at SD Parulian 2 Medan. The method used in this study is a qualitative method with data collection techniques, namely by means of observation, documentation, and interviews. The results of the study show that there are still some students who do not focus on the online learning system, lack of online learning facilities such as the internet and so on. Then also the unpreparedness of the guardians of students and teachers in facing the online learning. In the implementation of online learning, teachers often use WhatsApp to communicate with students and their parents. In addition, WhatsApp is used by teachers to share information related to learning materials. In conclusion, the implementation of online learning at iSD iParulian i2 Medan was not carried out properly, it can be seen from the results of the study due to the constraints of the lack of active students, limited internet facilities and the use of other learning media besides WhatsApp which is still lacking. The solution to overcome this obstacle is the readiness of parents, such as accompanying children when learning online and providing online learning facilities such as cellphones and internet quota.   Keywords: Covid-19, Student Learning Activities, Online Learnin

Performance of Lecturers in Preventing Learning Loss Hypotension

This study aims to determine the refunctional performance of lecturers in preventing hypotensive learning loss in Indonesian language and literature education study program students.  This research is a type of qualitative research. The sample of this research comes from students of the Indonesian language and literature education study program. Data collection techniques are interviews and documentation. Data analysis consists of data reduction, data presentation, and drawing a conclusion. The results of this study conclude that the potential learning loss that arises is characterized by the loss of interaction between lecturers and students (86%) and interaction between students and students (80%) and students cannot concentrate (60%) and other factors (40%).  The survey results stated that lecturers experienced work stress when facing changes in the learning process from face-to-face (offline) to online (online)

Analysis of Extrinsic Elements in the Novel Rindu By Tere

Literature is the result of a writer's disclosure of the problems of human life in all its aspects, which is a combination of imagination, expression and creativity. Literary works are the author's expression of the world through literary works. The aim of this research is to explain the relationship between extrinsic elements in the sociocultural form of culture depicted in the Novel Rindu by Tere Liye. The data is then classified, interpreted, and studied. The research results show that the Novel Rindu Tere Liye shows the relationship between extrinsic elements and sociocultural and cultural elements in society. This is shown by the combination of two languages, namely Indonesian and Dutch, in the interactions of the characters, and by the knowledge that tells the story of the long journey of the Tere Liye pilgrimage in 1938. The community organization depicted is ordinary people, and the equipment system which is described as still using tr. This study provides an overview of how the external elements of the novel interact with sociocultural and cultural aspects of society

Student Digital Literacy Competence Study Language and Literature Education Program Indonesia

This study aims to determine the digital literacy competence of Indonesian Language and Literature Education Study Program students. This study used a descriptive qualitative method to process the data from the sixth-semester student at HKBP Nommensen University. The results of this study found that students had good basic skills, major skills, intermediate skills, advanced skills, and literacy skills. However, the technical capabilities are still relatively poor. In (1) Basic Competencies, some problems are resolved properly, there are also several topical problems that still exist but at least there is an overview of problem-solving. (2) Students' Basic Competencies have a fairly good introduction to the basics of computer equipment. (3) Students' Intermediate Competencies increase at this stage, namely understanding various features on laptops, using printers, and using Ms. applications. Word and use of e-mail applications. The mastery of this competency is due to the fact that informants often carry out these activities so that they are more accustomed to their use. (4) Advanced Competencies to access information using search engines and online databases are good. (5) Technical Competencies of the Indonesian Language and Literature Study Program students as research informants do not yet have technical expertise regarding hardware and software. Informants have not been able to repair damage to digital equipment even at a simple level. (6) Students' Digital Literacy Proficiency does not yet have sufficient literacy skills starting from formulating a search plan, establishing a search strategy, organizing, processing, applying and communicating information, and understanding standard citation formats, and do not have the effort to communicate information with technology

The extraordinary evolutionary history of the reticuloendotheliosis viruses

The reticuloendotheliosis viruses (REVs) comprise several closely related amphotropic retroviruses isolated from birds. These viruses exhibit several highly unusual characteristics that have not so far been adequately explained, including their extremely close relationship to mammalian retroviruses, and their presence as endogenous sequences within the genomes of certain large DNA viruses. We present evidence for an iatrogenic origin of REVs that accounts for these phenomena. Firstly, we identify endogenous retroviral fossils in mammalian genomes that share a unique recombinant structure with REVs—unequivocally demonstrating that REVs derive directly from mammalian retroviruses. Secondly, through sequencing of archived REV isolates, we confirm that contaminated Plasmodium lophurae stocks have been the source of multiple REV outbreaks in experimentally infected birds. Finally, we show that both phylogenetic and historical evidence support a scenario wherein REVs originated as mammalian retroviruses that were accidentally introduced into avian hosts in the late 1930s, during experimental studies of P. lophurae, and subsequently integrated into the fowlpox virus (FWPV) and gallid herpesvirus type 2 (GHV-2) genomes, generating recombinant DNA viruses that now circulate in wild birds and poultry. Our findings provide a novel perspective on the origin and evolution of REV, and indicate that horizontal gene transfer between virus families can expand the impact of iatrogenic transmission events

Solid-phase molecular recognition of cytosine based on proton-transfer reaction. Part II. supramolecular architecture in the cocrystals of cytosine and its 5-Fluoroderivative with 5-Nitrouracil

<p>Abstract</p> <p>Background</p> <p>Cytosine is a biologically important compound owing to its natural occurrence as a component of nucleic acids. Cytosine plays a crucial role in DNA/RNA base pairing, through several hydrogen-bonding patterns, and controls the essential features of life as it is involved in genetic codon of 17 amino acids. The molecular recognition among cytosines, and the molecular heterosynthons of molecular salts fabricated through proton-transfer reactions, might be used to investigate the theoretical sites of cytosine-specific DNA-binding proteins and the design for molecular imprint.</p> <p>Results</p> <p>Reaction of cytosine (Cyt) and 5-fluorocytosine (5Fcyt) with 5-nitrouracil (Nit) in aqueous solution yielded two new products, which have been characterized by single-crystal X-ray diffraction. The products include a dihydrated molecular salt (CytNit) having both ionic and neutral hydrogen-bonded species, and a dihydrated cocrystal of neutral species (5FcytNit). In CytNit a protonated and an unprotonated cytosine form a triply hydrogen-bonded aggregate in a self-recognition ion-pair complex, and this dimer is then hydrogen bonded to one neutral and one anionic 5-nitrouracil molecule. In 5FcytNit the two neutral nucleobase derivatives are hydrogen bonded in pairs. In both structures conventional N-H^...O, O-H^...O, N-H^+...N and N-H^...N^-intermolecular interactions are most significant in the structural assembly.</p> <p>Conclusion</p> <p>The supramolecular structure of the molecular adducts formed by cytosine and 5-fluorocytosine with 5-nitrouracil, CytNit and 5FcytNit, respectively, have been investigated in detail. CytNit and 5FcytNit exhibit widely differing hydrogen-bonding patterns, though both possess layered structures. The crystal structures of CytNit (D<it>p</it>k_a= -0.7, molecular salt) and 5FcytNit (D<it>p</it>k_a= -2.0, cocrystal) confirm that, at the present level of knowledge about the nature of proton-transfer process, there is not a strict correlation between the D<it>p</it>k_avalues and the proton transfer, in that the acid/base <it>p</it>k_astrength is not a definite guide to predict the location of H atoms in the solid state. Eventually, the absence in 5FcytNit of hydrogen bonds involving fluorine is in agreement with findings that covalently bound fluorine hardly ever acts as acceptor for available Brønsted acidic sites in the presence of competing heteroatom acceptors.</p

Serum levels of osteoprotegerin and receptor activator of nuclear factor -κB ligand in children with early juvenile idiopathic arthritis: a 2-year prospective controlled study

<p>Abstract</p> <p>Background</p> <p>The clinical relevance of observations of serum levels of osteoprotegerin (OPG) and receptor activator of nuclear factor -κB ligand (RANKL) in juvenile idiopathic arthritis (JIA) is not clear. To elucidate the potential role of OPG and RANKL in JIA we determined serum levels of OPG and RANKL in patients with early JIA compared to healthy children, and prospectively explored changes in relation to radiographic score, bone and lean mass, severity of the disease, and treatment.</p> <p>Methods</p> <p>Ninety children with early oligoarticular or polyarticular JIA (ages 6-18 years; mean disease duration 19.4 months) and 90 healthy children individually matched for age, sex, race, and county of residence, were examined at baseline and 2-year follow-up. OPG and RANKL were quantified by enzyme-immunoassay. Data were analyzed with the use of t-tests, ANOVA, and multiple regression analyses.</p> <p>Results</p> <p>Serum OPG was significantly lower in patients than controls at baseline, and there was a trend towards higher RANKL and a lower OPG/RANKL ratio. Patients with polyarthritis had significantly higher increments in RANKL from baseline to follow-up, compared to patients with oligoarthritis. RANKL was a significant negative predictor for increments in total body lean mass. Patients who were receiving corticosteroids (CS) or disease-modifying antirheumatic drugs (DMARDs) at follow-up had higher OPG/RANKL ratio compared with patients who did not receive this medication.</p> <p>Conclusions</p> <p>The data supports that levels of OPG are lower in patients with JIA compared to healthy children, and higher levels of RANKL is associated with more serious disease. RANKL was a significant negative predictor of lean mass in patients with JIA. The OPG/RANKL ratio was higher in patients on DMARDs or CS treatment.</p

Gap junctions in olfactory neurons modulate olfactory sensitivity

<p>Abstract</p> <p>Background</p> <p>One of the fundamental questions in olfaction is whether olfactory receptor neurons (ORNs) behave as independent entities within the olfactory epithelium. On the basis that mature ORNs express multiple connexins, I postulated that gap junctional communication modulates olfactory responses in the periphery and that disruption of gap junctions in ORNs reduces olfactory sensitivity. The data collected from characterizing connexin 43 (Cx43) dominant negative transgenic mice OlfDNCX, and from calcium imaging of wild type mice (WT) support my hypothesis.</p> <p>Results</p> <p>I generated OlfDNCX mice that express a dominant negative Cx43 protein, Cx43/β-gal, in mature ORNs to inactivate gap junctions and hemichannels composed of Cx43 or other structurally related connexins. Characterization of OlfDNCX revealed that Cx43/β-gal was exclusively expressed in areas where mature ORNs resided. Real time quantitative PCR indicated that cellular machineries of OlfDNCX were normal in comparison to WT. Electroolfactogram recordings showed decreased olfactory responses to octaldehyde, heptaldehyde and acetyl acetate in OlfDNCX compared to WT. Octaldehyde-elicited glomerular activity in the olfactory bulb, measured according to odor-elicited <it>c-fos </it>mRNA upregulation in juxtaglomerular cells, was confined to smaller areas of the glomerular layer in OlfDNCX compared to WT. In WT mice, octaldehyde sensitive neurons exhibited reduced response magnitudes after application of gap junction uncoupling reagents and the effects were specific to subsets of neurons.</p> <p>Conclusions</p> <p>My study has demonstrated that altered assembly of Cx43 or structurally related connexins in ORNs modulates olfactory responses and changes olfactory activation maps in the olfactory bulb. Furthermore, pharmacologically uncoupling of gap junctions reduces olfactory activity in subsets of ORNs. These data suggest that gap junctional communication or hemichannel activity plays a critical role in maintaining olfactory sensitivity and odor perception.</p

An overview of NMR-based metabolomics to identify secondary plant compounds involved in host plant resistance

Secondary metabolites provide a potential source for the generation of host plant resistance and development of biopesticides. This is especially important in view of the rapid and vast spread of agricultural and horticultural pests worldwide. Multiple pests control tactics in the framework of an integrated pest management (IPM) programme are necessary. One important strategy of IPM is the use of chemical host plant resistance. Up to now the study of chemical host plant resistance has, for technical reasons, been restricted to the identification of single compounds applying specific chemical analyses adapted to the compound in question. In biological processes however, usually more than one compound is involved. Metabolomics allows the simultaneous detection of a wide range of compounds, providing an immediate image of the metabolome of a plant. One of the most universally used metabolomic approaches comprises nuclear magnetic resonance spectroscopy (NMR). It has been NMR which has been applied as a proof of principle to show that metabolomics can constitute a major advancement in the study of host plant resistance. Here we give an overview on the application of NMR to identify candidate compounds for host plant resistance. We focus on host plant resistance to western flower thrips (Frankliniella occidentalis) which has been used as a model for different plant species