Judul: Relationship between Diet Quality and Physical Activity with Nutritional Status of Adolescents during The Covid-19 Pandemic
Abstrak: Pandemi Covid-19 menyebabkan adanya pembatasan aktivitas yang dapat memengaruhi kualitas makan dan aktivitas fisik remaja. Tujuan dari penelitian ini adalah untuk menganalisis hubungan kualitas diet dan aktivitas fisik dengan status gizi remaja selama masa pandemi. Desain penelitian adalah cross sectional dengan jumlah subjek sebanyak 100 siswa di SMA Negeri 5 Bogor. Pengumpulan data dilakukan secara semi daring. Data kualitas diet dihitung dari konversi food recall 2x24 jam menggunakan indeks Diet Quality Indeks for Adolescents (DQI-A) yang dimodifikasi menggunakan Pedoman Gizi Seimbang 2014. Data aktivitas fisik didapatkan dengan wawancara subjek menggunakan International Physical Activity Questionnare Short Form (IPAQ-SF). Status gizi ditentukan menggunakan indikator z-score IMT/U. Sebagian besar subjek (60%) merupakan perempuan dengan rata-rata usia 16,8±0,6 tahun. Status gizi subjek berdasarkan IMT/U secara keseluruhan tergolong normal dengan persentase 78%. Rata-rata skor DQI-A subjek yaitu 52,6%±12,1% yang tergolong cukup baik. Aktivitas fisik subjek tergolong rendah ke sedang. Tidak terdapat hubungan yang signifikan antara kualitas diet dengan IMT/U (p>0,05). Namun, status gizi IMT/U memiliki hubungan signifikan dengan skor METs (p<0,05)., The Covid-19 pandemic has led to restrictions on activities that can affect the quality of food and physical activity in adolescents. The purpose of this study was to analyze the relationship between diet quality and physical activity with the nutritional status of adolescents during the pandemic. The research design was cross-sectional with the number of subjects as many as 100 students at SMA Negeri 5 Bogor. Data collection is done semi-online. Diet quality data was calculated from the 2x24 hour food recall conversion using the Diet Quality Index for Adolescents (DQI-A) modified using Balanced Nutrition Guidelines 2014. Physical activity data was obtained by interviewing subjects using the International Physical Activity Questionnare Short Form (IPAQ-SF). Nutritional status was determined using the BMI for age z-score indicator. Most of the subjects (60%) were female with an average age of 16.8±0.6 years old. Overall nutritional status based on BMI for age is normal with a percentage of 78%. The average DQI-A score of the subjects was 52.6%±12.1% which classified quite good. Physical activity is classified as low to moderate. There was no significant relationship between diet quality and BMI for age (p>0.05). However, BMI for age had a significant relationship with METs scores (p<0.05)
Keyword: Adolescents, diet quality, DQI-A, nutritional status, physical activity

Judul: Nutrients Intake, Physical Activity, and Body Perception of Senior High School Students during the Covid-19 Pandemic in Bogor City
Abstrak: Penelitian ini bertujuan untuk mengidentifikasi asupan gizi, aktivitas fisik, dan persepsi tubuh siswa dan siswi SMA di Kota Bogor selama masa pandemi Covid-19. Desain penelitian ini adalah cross sectional study dengan jumlah subjek sebanyak 100 orang. Pengumpulan data seluruhnya dilakukan secara daring. Data asupan gizi didapatkan dari estimated food record 3x24 jam. Aktivitas fisik siswa diukur menggunakan International Physical Activity Questionnaire Short Form (IPAQ-SF). Status gizi ditentukan menggunakan indikator z-score IMT/U. Persepsi tubuh ditentukan berdasarkan hasil pengisian Figure Rating Scale (FRS). Sebagian besar status gizi subjek tergolong gizi baik. Mayoritas tingkat kecukupan energi, protein, lemak, dan karbohidrat subjek tergolong defisit berat. Subjek laki-laki (30,0%) cenderung memiliki kecukupan protein normal, sedangkan perempuan (43,0%) tergolong defisit berat. Aktivitas fisik subjek selama pandemi tergolong sedang. Mayoritas subjek memiliki persepsi tubuh positif. Tidak terdapat hubungan yang signifikan antara asupan gizi dan aktivitas fisik dengan status gizi, begitu pula antara status gizi dengan persepsi tubuh (p>0,05)., This study aims to identify nutrients intake, physical activity, and body perception of senior high school students in Bogor City during the Covid-19 pandemic. The design of this research is a cross-sectional study with 100 students. All data collection is done online. Nutrients intake data was obtained from 3x24 hours estimated food record. Students' physical activity was measured using the International Physical Activity Questionnaire Short Form (IPAQ-SF). Nutritional status was determined using the BMI for age z-score indicator. Body perception is determined based on Figure Rating Scale (FRS). Most of the subjects have normal nutritional status. Most of the subjects' energy, protein, fat, and carbohydrate adequacy levels were classified as severe deficits. Male subjects (30.0%) tended to have normal protein adequacy, while female subjects (43.0%) were classified as having severe deficits. The subject's physical activity during the pandemic was moderate. Most of the subjects had a positive body perception. There was no significant relationship between nutrients intake and physical activity with nutritional status, as well as between nutritional status and body perception (p>0.05).
Keyword: Adolescent, Body perception, Nutrients intake, Nutritional status, Physical activity

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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