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: Correlation Between Eating Behavior and Body Image with Nutritional Status among High School Students in Bogor
Abstrak: Dewasa ini remaja mulai memerhatikan perubahan fisik yang terjadi pada mereka dan tak jarang merasa tidak puas dengan bentuk tubuh yang dimiliki. Hal tersebut dapat mendorong remaja untuk melakukan upaya-upaya tertentu untuk membuat bentuk tubuh sesuai keinginannya, seperti membatasi asupan makan dan melakukan diet berlebih yang dapat memengaruhi perilaku makan, persepsi diri terhadap citra tubuh, dan status gizi. Penelitian ini bertujuan untuk menganalisis hubungan antara perilaku makan dan body image dengan status gizi siswa SMA di Kota Bogor. Desain penelitian ini adalah cross-sectional study. Jumlah sampel yang digunakan sebanyak 114 siswa SMA di Kota Bogor. Pengumpulan data dilakukan melalui wawancara dan self-administered secara online. Sebagian besar subjek memiliki status gizi normal (81,6%), tergolong dalam tipe perilaku makan external eating (75,4%), memiliki persepsi body image negatif (51,8%), dan memiliki kebiasaan makan yang kurang baik (53,5%). Terdapat hubungan signifikan antara status gizi siswa SMA dengan perilaku makan restrained eating (p=0,018) dan body image (p=0,000). Tidak terdapat hubungan signifikan antara perilaku makan emotional eating dan external eating terhadap status gizi (p>0,05). Dapat disimpulkan bahwa perilaku makan dan persepsi body image memengaruhi status gizi siswa., These days, adolescence begine to pay attention to the physical changes that occur to them and often feel dissatisfied with their body shape. This can encourage adolescents to make certain efforts to make the body shape according to their wishes, such as limiting food intake and doing excessive diets that can affect eating behavior, body image, and nutritional status. The purpose of this study was to analyze the correlation between eating behavior and body image with nutritional status among high school students in Bogor. The design of this study was a cross-sectional study. The number of samples used in this study were 114 high school students. Data was collected through interviews and self-administrated online. Most of the subjects had normal nutritional status (81.6%), belonged to the external eating behavior (75.4%), have a negative body image perception (51.8%), had unhealthy eating habits (53.5%). There is a significant relationship between nutritional status in high school students with restrained eating (p=0.018) and body image (p=0.000). However, there is no significant relationship between emotional eating and external eating behavior on nutritional status (p>0.05). It can be concluded that eating behavior and perception of body image affect the nutritional status of students.
Keyword: adolescent, body image, nutritional status, food habits, eating behavior

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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