PENERAPAN PEER TUTORING UNTUK MENINGKATKAN PEMAHAMAN KONSEP JUMLAH DAN SELISIH SUDUT [THE IMPLEMENTATION OF PEER TUTORING TO IMPROVE CONCEPTUAL UNDERSTANDING OF SUM AND DIFFERENCE ANGLES]

Conceptual understanding is a student's ability to understand a concept that has been studied. Based on observation of daily test results, it is known that some students do not understand the concept of the sum and difference angle trigonometry formulas. This is demonstrated by achieving the standard of success of the number of students who achieved the Minimum Standard of Achievement set by the school of 75.  To improve the situation, researchers implemented the Peer Tutoring method, which aims to improve the understanding of the concept of the sum and difference angle trigonometry formulas and find out how the application of Peer Tutoring can improve the conceptual understanding of the student. This research uses the Class Action Research (CAR) method based on Kemmis & McTaggart spiral model. This research was conducted in grade XI MIPA 2 SMA YZ in Semarang with 23 students. Instruments used for data collection are daily tests, observation sheets, checklists of mentor teachers and other teachers, mentor teacher interviews, and research reflection journals. The data obtained is calculated using descriptive statistics and analyzed qualitatively descriptively. Based on the analysis results, it can be concluded that the implementation of Peer Tutoring could improve student's conceptual understanding of the sum and difference.  The increase was seen from the number of students who achieved the Minimum Standard of Achievement in the first cycle, which was 60.87% and in the second cycle was 78.26%. Therefore, the achievement has exceeded the standard of success is used, which was 75% of the number of students who reach the Minimum Standard of Achievement.BAHASA INDONESIA ABSTRACT: Pemahaman konsep adalah kemampuan siswa untuk memahami suatu konsep yang telah dipelajari. Berdasarkan observasi hasil tes harian, diketahui bahwa sebagian siswa belum memahami konsep rumus jumlah dan selisih sudut trigonometri. Hal tersebut ditunjukkan dengan belum tercapainya standar keberhasilan jumlah siswa yang mencapai Kriteria Ketuntasan Minimum (KKM) yang ditetapkan sekolah sebesar 75. Untuk memperbaiki keadaan tersebut, peneliti menerapkan metode Peer Tutoring, yang bertujuan selain untuk memperbaiki dan meningkatkan pemahaman konsep rumus jumlah dan selisih sudut trigonometri, juga untuk mengetahui bagaimana penerapan Peer Tutoring dapat meningkatkan pemahaman konsep siswa. Penelitian ini menggunakan metode Penelitian Tindakan Kelas (PTK) berdasarkan model spiral Kemmis & McTaggart. Penelitian ini dilakukan pada kelas XI MIPA 2 SMA YZ di Semarang dengan jumlah siswa sebanyak 23 orang. Instrumen yang digunakan untuk pengumpulan data adalah tes harian, lembar observasi guru mentor dan guru lain, wawancara guru mentor, dan jurnal refleksi peneliti. Data yang diperoleh dikalkulasi menggunakan statistik deskriptif dan dianalisis secara kualitatif deskriptif. Berdasarkan hasil penelitian dapat disimpulkan bahwa penerapan Peer Tutoring dapat meningkatkan pemahaman konsep rumus jumlah dan selisih sudut trigonometri pada siswa kelas XI MIPA 2 SMA YZ di Semarang. Peningkatan tersebut terlihat dari jumlah siswa yang mencapai Kriteria Ketuntasan Minimum (KKM) pada siklus pertama mencapai 60,87%, meningkat pada siklus kedua menjadi 78,26%. Pencapain tersebut telah melebihi standar keberhasilan yang digunakan yaitu 75% dari jumlah siswa yang mencapai KKM

Near-infrared supercontinuum source by intracavity silica-based highly-nonlinear fiber

Near-infrared supercontinuum generation by using silica-based highly-nonlinear fiber placed inside of the ring-cavity of an erbium-doped fiber laser pulsed by mode-locking is experimentally demonstrated. Only one erbium-doped fiber amplifier is employed to generate supercontinuum with a spectral width as long as 830 nm (from 1205 to 2035 nm) and a spectral power higher than -30 dBm/nm. To generate supercontinuum, it is not necessary a second amplifier to raise the power of the laser pulses coupled into the nonlinear fiber. Moreover, all the devices employed are commercial and available at any photonics laboratory. To the best of our knowledge, this is the first demonstration of this kind of device by pumping the nonlinear fiber in the third window of communications

Theoretical Analysis of Tunable Single-Core Comb Filter Based on MZI

<!-- /* Font Definitions */ @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:-1610611985 1107304683 0 0 159 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin-top:0in; margin-right:0in; margin-bottom:10.0pt; margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} .MsoPapDefault {mso-style-type:export-only; margin-bottom:10.0pt; line-height:115%;} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.0in 1.0in 1.0in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} --> In this work, a theoretical analysis of single core tunable comb filter based on Mach-Zehnder (M-Z) interferometer is proposed and demonstrated. The proposed filter consists of one QWP, one HWP, one SMF and onePMF segment consists of two PMF lengths. Depending on the dynamic settings of wavelength of the input signal, refractive index and length of the fiber material, the comb filter provides the channel spacing tenability, and peak wavelength position switchability. The proposed comb filter is polarization insensitive as PMF is used

Bio-products from algae-based biorefinery on wastewater: A review

Increasing resource demand, predicted fossil resources shortage in the near future, and environmental concerns due to the production of greenhouse gas carbon dioxide have motivated the search for alternative ‘circular’ pathways. Among many options, microalgae have been recently ‘revised’ as one of the most promising due to their high growth rate (with low land use and without competing with food crops), high tolerance to nutrients and salts stresses and their variability in biochemical composition, in so allowing the supply of a plethora of possible bio-based products such as animal feeds, chemicals and biofuels. The recent raising popularity of Circular Bio-Economy (CBE) further prompted investment in microalgae, especially in combination with wastewater treatment, under the twofold aim of allowing the production of a wide range of bio-based products while bioremediating wastewater. With the aim of discussing the potential bio-products that may be gained from microalgae grown on urban wastewater, this paper presents an overview on microalgae production with particular emphasis on the main microalgae species suitable for growth on wastewater and the obtainable bio-based products from them. By selecting and reviewing 76 articles published in Scopus between 1992 and 2020, a number of interesting aspects, including the selection of algal species suitable for growing on urban wastewater, wastewater pretreatment and algal-bacterial cooperation, were carefully reviewed and discussed in this work. In this review, particular emphasis is placed on understanding of the main mechanisms driving formation of microalgal products (such as biofuels, biogas, etc.) and how they are affected by different environmental factors in selected species. Lastly, the quantitative information gathered from the articles were used to estimate the potential benefits gained from microalgae grown on urban wastewater in Campania Region, a region sometimes criticized for poor wastewater management

Challenges and opportunities for more efficient water use and circular wastewater management. The case of Campania Region, Italy

By 2050, global demand for water is expected to increase by some 55% due to population growth and urbanization. The utilization of large amounts of freshwater in the world, generate huge volumes of wastewater of which, globally, more than 80% is discharged without treatment, thus causing impacts on aquatic ecosystems, human health and economic productivity. More sustainable practices of wastewater management are expected as a way towards circular bioeconomy (CBE) processes, whose goal is to implement closed systems promoting the systematic use of recycling, reuse and recovery of bioproducts and by-products and the reduction of waste generation. This approach, if adopted in the water and wastewater sector, can ensure environmental, economic and social benefits. The reuse of wastewater, on the one hand, reduces the volume of wastewater and the pressure on water bodies; on the other hand, the recovery of nutrients (P or N) and/or other high value bioproducts (biogas, cellulose, biopolymers) from wastewater offers numerous advantages in terms of supplying new raw bio-based materials that can be refed back to supply chains (thus substituting fossil resources) and, at the same time, producing cleaner water to be reused. Nevertheless, while in Europe many industries have demonstrated the ability to recycle and reuse water, in many regions of Italy the sustainable management of water and wastewater is not yet consolidated. In this study we explore the available technological, economic and environmental options concerning water use and wastewater treatment and we apply them to design appropriate scenarios for improved use efficiency and circular management. A comprehensive literature review of the most promising wastewater treatment processes for resources and energy valorization was conducted. The recovery of PHAs, struvite, nitrogen and algal biomass, as potential substitutes for conventional PET, phosphate and nitrogen chemical fertilizers and electricity, respectively, in addition to reusable treated water, were hypothesized and carefully discussed. Resulting scenarios are tested against the present situation of Campania Region (situated in Southern Italy) based on population and demand statistics, in order to develop strategies and policies potentially applicable locally and elsewhere

HSV-1 and endogenous retroviruses as risk factors in demyelination

Herpes simplex virus type 1 (HSV-1) is a neurotropic alphaherpesvirus that can infect the peripheral and central nervous systems, and it has been implicated in demyelinating and neurodegenerative processes. Transposable elements (TEs) are DNA sequences that can move from one genomic location to another. TEs have been linked to several diseases affecting the central nervous system (CNS), including multiple sclerosis (MS), a demyelinating disease of unknown etiology influenced by genetic and environmental factors. Exogenous viral transactivators may activate certain retrotransposons or class I TEs. In this context, several herpesviruses have been linked to MS, and one of them, HSV-1, might act as a risk factor by mediating processes such as molecular mimicry, remyelination, and activity of endogenous retroviruses (ERVs). Several herpesviruses have been involved in the regulation of human ERVs (HERVs), and HSV-1 in particular can modulate HERVs in cells involved in MS pathogenesis. This review exposes current knowledge about the relationship between HSV-1 and human ERVs, focusing on their contribution as a risk factor for MS

Prognostic value of Iron, Nutritional Status Indexes and Acute Phase Protein in Acute Coronary Syndrome.

Background. The relation between the inflammatory status during unstable angina and nutritional parameters has not been well described. We sought to investigate the relation between the acute inflammatory status, as evaluated on the basis of high C-reactive protein (CRP) and serum amyloid A levels and laboratory indexes of iron and nutritional status in patients with unstable angina, and whether the variations in iron levels have a prognostic significance.Methods. The study population consisted of 98 patients admitted to our facility with unstable (group 1: 64 consecutive patients, 52 males, 12 females, mean age 66 \ub1 10 years) or stable angina(group 2: 34 patients, 30 males, 4 females, mean age 65 \ub1 9 years). The hemoglobin levels, the erythrocyte mean cell volume, serum iron levels, the increase in transferrin levels, the decrease in the percent transferrin saturation, ferritin levels, the nutritional status, and the CRP and serum amyloid A levels were measured.Results. On the basis of a CRP value > 1 mg/dl, 47 patients with unstable angina and 4 patients with stable angina were identified as having active inflammatory disease. The presence of inflammation was associated with significantly lower mean values of hemoglobin, erythrocyte mean cell volume, serum iron and transferrin levels, and percent transferrin saturation in comparison with patients without inflammation. A significant inverse correlation coefficient between a CRP level > 1 mg/dl and hemoglobin, transferrin levels and percent transferrin saturation was observed: the strongest correlation was with serum iron levels. The relative risk of total cardiac events was significantlygreater in patients with low serum iron levels than in those with high serum iron levels.Conclusions. Patients with acute inflammation present altered iron status indexes. Increased CRP levels and reduced serum iron levels are associated with a worse outcome in patients with unstable angina

Analysis of meticillin-susceptible and meticillin-resistant biofilm-forming Staphylococcus aureus from catheter infections isolated in a large Italian hospital

Several characteristics were analysed in 37 Staphylococcus aureus isolates from nosocomial catheter infections: the PFGE profile after SmaI digestion of chromosomal DNA, the ability to form a biofilm on a polystyrene surface, antibiotic susceptibility patterns (penicillin, oxacillin, erythromycin, tetracycline, clindamycin, telithromycin, gentamicin, ciprofloxacin, quinupristin/dalfopristin, rifampicin, vancomycin and linezolid), and the presence of genetic determinants of antibiotic resistance and biofilm formation. All strains but three (92 %) were able to grow on a plastic surface as a biofilm. An almost complete association was found between phenotypes and genotypic traits of antibiotic resistance, whilst PFGE profiling showed the highly polyclonal composition of the set of strains under study. Sixteen isolates (43 %) were meticillin-resistant and were subjected to staphylococcal cassette chromosome mec (SCCmec) and cassette chromosome recombinase (ccr) complex type determination by multiplex PCR. Only a subgroup of six strains belonged to the archaic clone PFGE type and bore the SCCmec/ccrAB type I structure. Among the remaining strains some presented small rearrangements of the SCCmec/ccrAB genetic locus, whilst others could barely be traced back to a known structural type. These observations suggest that, at the local level and at a particular site of infection, S. aureus may show great genetic variability and escape the general rule of expansion of the S. aureus pandemic clones

Coherent artifact and time-dependent polarization in amplified ultrafast erbium-doped fibre lasers

Mode-locked erbium-doped fibre lasers are ultrashort pulsed sources widely studied due to their versatility and multiple applications in the near infrared range. Here we present the experimental study of the emission of a passive mode-locked erbium-doped fibre laser with an amplification stage outside the cavity by means of Frequency Resolved Optical Gating (FROG) and spectral interferometry. Due to shot-to-shot instabilities, the FROG traces can be understood as the combination of two different traces, corresponding to the coherent artifact and the average pulse characteristics. We have modified a Principal Components Generalized Projections Algorithm, in order to make it able to retrieve efficiently both the coherent artifact and the average pulse. In addition, we study the temporal dependence of the polarization, showing that the pulses present time-dependent polarization with a stable spectral relative phase between the horizontal and vertical projections. Up to our knowledge, this is the first experimental study that shows the FROG measurements of unstable pulse trains associated with the coherent artifact and analyses the time-dependent polarization in ultrafast fibre lasers