PENGEMBANGAN LEMBAR KERJA SISWA BERBASIS PENDEKATAN PROBLEM BASED LEARNING PADA MATERI OPERASI ALJABAR UNTUK SISWA SMP/MTs

ABSTRAK Nadya Tafari, (2021) : Pengembangan Lembar Kerja Siswa Matematika Berbasis Pendekatan Problem Based Learning (PBL) pada Materi Operasi Aljabar Penelitian ini bertujuan untuk mengembangkan dan menghasilkan bahan ajar berupa berupa Lembar Kerja Siswa Matematika berbasis pendekatan Problem Based Learning (PBL) pada materi Operasi. Jenis penelitian ini merupakan penelitian pengembangan (Research and Development) dengan menggunakan model ADDIE (Analysis, Design, Development, Implementation, Evaluation). Penelitian ini dilakukan di MTs Negeri 1 Pekanbaru tahun ajaran 2020/2021. Subjek penelitian adalah para ahli teknologi pendidikan dan ahli materi pembelajaran yang berasal dari dosen, serta siswa kelas VII MTs Negeri 1 Pekanbaru sebagai kelompok kecil. Teknik pengumpulan data yang digunakan berupa tes, angket, dokumentasi dan wawancara. Intsrumen penelitian berupa pedoman wawancara, dokumen pendukung, instrumen validitas yang terdiri dari lembar validasi instrumen penelitian, lembar validasi LKS oleh ahli teknologi pendidikan dan materi pembelajaran, instrumen kepraktisan yaitu angket respon siswa dan instrument keefektifan yaitu soal tes. Data yang diperoleh kemudian dianalisis dengan teknik analisis data kualitatif dan teknik analisis data kuantitatif. Berdasarkan uji validitas, LKS berbasis pendekatan PBL dinyatakan kategori sangat valid dengan tingkat kevalidan 88,29%. Berdasarkan uji kepraktisan, LKS berbasis pendekatan PBL dinyatakan kategori sangat praktis dengan tingkat kepraktissan kelompok kecil 85,52%, sedangkan untuk kelompok terbatas dan efektivitas tidak dapat dilakukan karena sekolah tutup dalam waktu yang cukup lama selama akibat covid-19. Dengan demikian hasil penelitian inidapat digunakan guru dalam meningkatkan kualitas pembelajaran pada materi operasi aljabar di kelas. Kata Kunci: Lembar Kerja Siswa, Pendekatan Problem Based Learning (PBL), Operasi Aljaba

Morfološke i strukturne značajke biofilmova na bazi zeina s dodatkom ksantanske gume

Morphological and structural characteristics of zein-based biofilms have been studied in this work. The sorbitan component in the control formulation of the film was substituted with xanthan gum at concentrations between 0.01 and 0.04 % to analyze its effect on lipid dispersion. Scanning electron microscopy (SEM) showed a surface for the control (0 % xanthan) with good lipid distribution. However, when the samples were investigated by optical microscopy (OM), lipid globules in the control biofilm appeared larger and more dispersed in the matrix than in the other samples. Fourier transform infrared (FTIR) spectroscopy indicated that xanthan concentrations deeply affected C=O linkages from amide I group, as well as the functional N-H group of amide II of the zein structure. Other weak interactions of amide I and II with carboxylic acids and aliphatic compounds were also observed. UV/VIS analysis as well as transparency measurements indicated that the addition of xanthan to the film matrix lowered significantly its transparency properties. Overall, the addition of xanthan gum favoured lipid dispersion in the matrix, making biofilms more homogeneous, although less transparent.U ovom su radu ispitane morfološke i strukturne značajke biofilmova na bazi zeina. U formulaciju je umjesto sorbitana dodana ksantanska guma koncentracije od 0,01 do 0,04 %, kako bi se ispitao utjecaj ksantana na disperziju lipida u biofilmu. Pretražnom elektronskom mikroskopijom prikazan je dobar raspored lipida na površini kontrolnog uzorka biofilma (s 0 % ksantana), a optičkim je mikroskopom utvrđeno da su lipidni globuli veći i raspršeniji u matriksu kontrolnog uzorka nego u ostalim uzorcima. Fourierova transformirana infracrvena spektroskopija pokazala je da koncentracija ksantana bitno utječe na C=O vezu amidne skupine I i na funkcionalnu N-H skupinu amida II u zeinu. Također su utvrđene slabe interakcije amida I i II s karboksilnim kiselinama i alifatskim skupinama. UV/VIS analizom i mjerenjem transparentnosti filmova ustanovljeno je da dodatak ksantana matriksu znatno smanjuje transparentnost filma. Zaključeno je da dodatak ksantanske gume poboljšava disperziju lipida u matriksu i homogenost, a smanjuje transparentnost filmova

Hip-hop is more than just music to me: a narrative study exploring the counter-stories of Black men elementary school teachers from the Hip-hop generation

In this qualitative dissertation study, the researcher utilizes a critical race methodology to address the dearth of Black men who teach in America's elementary school classrooms. Through the lens of a Black Feminist and Hip-Hop Feminist, the researcher explores the reasons Black men from the Hip-Hop generation become elementary school teachers and how growing up as part of the Hip-Hop generation has influenced their identity development and pedagogical awareness. The counter-stories of nine Black men elementary school teachers from the Hip-Hop generation were collected via a narrative method in which one-on-one interviews and a Facebook Focus Group were administered. The results of this study include five "purposes" for teaching: Teaching as an act of resistance; Teaching as an act of otherfathering; Teaching as a calling; Teaching as an act of passion; and Teaching as an expression of Hip-Hop. Furthermore, this study offers a discussion on the utilization of Hip-Hop as a viable form of critical pedagogy

Detecção de bordas em imagens de ressonância magnética por meio de processamento de imagenscom algoritmos genéticos

A detecção de bordas em imagens digitais é uma etapa importante do processamento e análise de imagens, pois permite a localização dos objectos presentes nas mesmas, bem como a extracção de características importantes para o seu reconhecimento, tais como rugosidade da borda e dimensões e forma do objecto. Na tentativa de obter resultados mais precisos, viários métodos de detecção de bordas têm sido propostos. Neste trabalho, aborda-se a aplicação de algoritmos genéticos para detectar bordas de regiões anormais em imagens de ressonância magnética, com o objectivo de auxiliar no diagnóstico de tumores cerebrais. Os algoritmos genéticos são métodos de busca e optimização baseados na evolução dos seres vivos proposta por Charles Darwin, que declarou que os seres vivos adaptados ao seu ambiente são os que possuem maiores chances de sobreviver e gerar descendência. Estes algoritmos possuem duas estruturas básicas (genes e cromossomos) e três operações (selecção, cruzamento e mutação). Para ser aplicado em processamento de imagens, cada pixel é considerado um gene e os cromossomos um grupo de genes, ou seja, uma região com um determinado número de pixels. Os resultados obtidos neste trabalho mostraram-se animadores na detecção de tumores cerebrais de difícil diagnóstico visual, melhorando a visualização do mesmo pelo especialista médico

Prevalence of Common Mental Disorders in a Rural District of Kenya, and Socio-Demographic Risk Factors

Association between common mental disorders (CMDs), equity, poverty and socio-economic functioning are relatively well explored in high income countries, but there have been fewer studies in low and middle income countries, despite the considerable burden posed by mental disorders, especially in Africa, and their potential impact on development. This paper reports a population-based epidemiological survey of a rural area in Kenya. A random sample of 2% of all adults living in private households in Maseno, Kisumu District of Nyanza Province, Kenya (50,000 population), were studied. The Clinical Interview Schedule-Revised (CIS-R) was used to determine the prevalence of common mental disorders (CMDs). Associations with socio-demographic and economic characteristics were explored. A CMD prevalence of 10.8% was found, with no gender difference. Higher rates of illness were found in those who were of older age and those in poor physical health. We conclude that CMDs are common in Kenya and rates are elevated among people who are older, and those in poor health

Mental distress in the general population in Zambia: Impact of HIV and social factors

<p>Abstract</p> <p>Background</p> <p>Population level data on mental health from Africa are limited, but available data indicate mental problems to represent a substantial public health problem. The negative impact of HIV on mental health suggests that this could particularly be the case in high prevalence populations. We examined the prevalence of mental distress, distribution patterns and the ways HIV might influence mental health among men and women in a general population.</p> <p>Methods</p> <p>The relationship between HIV infection and mental distress was explored using a sample of 4466 participants in a population-based HIV survey conducted in selected rural and urban communities in Zambia in 2003. The Self-reporting questionnaire-10 (SRQ-10) was used to assess global mental distress. Weights were assigned to the SRQ-10 responses based on DSM IV criteria for depression and a cut off point set at 7/20 for probable cases of mental distress. A structural equation modeling (SEM) was established to assess the structural relationship between HIV infection and mental distress in the model, with maximum likelihood ratio as the method of estimation.</p> <p>Results</p> <p>The HIV prevalence was 13.6% vs. 18% in the rural and urban populations, respectively. The prevalence of mental distress was substantially higher among women than men and among groups with low educational attainment vs. high. The results of the SEM showed a close fit with the data. The final model revealed that self-rated health and self perceived HIV risk and worry of being HIV infected were important mediators between underlying factors, HIV infection and mental distress. The effect of HIV infection on mental distress was both direct and indirect, but was particularly strong through the indirect effects of health ratings and self perceived risk and worry of HIV infection.</p> <p>Conclusion</p> <p>These findings suggest a strong effect of HIV infection on mental distress. In this population where few knew their HIV status, this effect was mediated through self-perceptions of health status, found to capture changes in health perceptions related to HIV, and self-perceived risk and worry of actually being HIV infected.</p