Article Per Year (5 Year)
p-Index From 2021 - 2026
1.908
P-Index
This Author published in this journals
All Journal Jurnal Biologi Tropis Yumary: Jurnal Pengabdian kepada Masyarakat Cendana Medical Journal
Koamesah, Sangguana Marthen Jacobus
Unknown Affiliation
Agriculture, Biological Sciences & Forestry Humanities Biochemistry, Genetics & Molecular Biology Economics, Econometrics & Finance Environmental Science Health Professions Immunology & microbiology Medicine & Pharmacology Public Health Social Sciences Other

Published : 11 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 11 Documents
Search

 1   2 
PKM Edukasi dan PHBS Pencegahan Cacingan Anak Usia Sekolah sebagai Upaya Menanggulangi Stunting di Kualin NTT Buntoro, Ika Febianti; Handoyo, Nicholas Edwin; Koamesah, Sangguana Marthen Jacobus; Folamauk, Conrad L. H.; Nurina, Rr.Listyawati; Muntasir, Muntasir
Yumary: Jurnal Pengabdian kepada Masyarakat Vol. 5 No. 3 (2025): Maret
Publisher : Penerbit Goodwood

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35912/yumary.v5i3.3306

Abstract

Purpose: This community service aims to provide educational interventions and knowledge about the importance of preventing worms, instilling good and correct PHBS behavior of washing hands in school-age children, checking the health of nails, hands, skin, and body weight, providing posters for preventing worms and air storage facilities for washing hands. Methodology: The activity consisted of three stages: preparation, implementation, and evaluation. The preparation stage involved site observation, communication with Taus Elementary School, obtaining permits, and providing initial information. Results: The results of this service showed positive results, as many as 52 Taus Elementary School children knew and carried out worm prevention by applying good information using the worm prevention pocketbook, the students were able to carry out demonstrations and practice active participation in carrying out PHBS washing their hands, had carried out health checks. Conclusions: Educational interventions such as lectures and PHBS practices can have a positive impact in increasing health awareness among students. A total of 52 students have the security and knowledge to prevent helminthiasis as one of the causes of stunting with the application of helminthiasis prevention pocket book. Limitations: This activity only reaches 1 Taos elementary school, Oni village, Kualin TTS sub-district, NTT. Contribution: This service is beneficial for schools and the community, maintaining health will endanger worms and increase PHBS hand washing for students and schools to become pilot centers for personal and community hygiene.
HUBUNGAN PENGETAHUAN GIZI DAN POLA KONSUMSI DENGAN STATUS GIZI PADA MAHASISWA FAKULTAS KEDOKTERAN UNIVERSITAS NUSA CENDANA Charina, Maria Selviana; Sagita, Sidarta; Koamesah, Sangguana Marthen Jacobus; Woda, Rahel Rara
Cendana Medical Journal Vol 10 No 1 (2022): April (Terbitan 23, Tahun 2022)
Publisher : Universitas Nusa Cendana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35508/cmj.v10i1.6829

Abstract

Gizi merupakan faktor terpenting dalam indikator kesehatan manusia terutama pada masa anak-anak dan remaja. Ketidakseimbangan antara zat gizi yang masuk ke dalam tubuh (intake) dengan kebutuhan zat gizi untuk metabolisme tubuh akan mempengaruhi keadaan status gizi. Masalah gizi pada mahasiswa, tidak boleh dianggap sepele karena mempengaruhi produktivitas mahasiswa, hal ini tentu berkaitan dengan peran mahasiswa kedokteran sebagai calon dokter dalam promosi kesehatan terutama di masa pandemi sekarang ini. Tujuan penelitian ini untuk mengetahui hubungan antara pengetahuan gizi dan pola konsumsi dengan status gizi pada mahasiswa Fakultas Kedokteran Universitas Nusa Cendana. Metode penelitian ini merupakan penelitian analitik observasional dengan rancangan cross sectional menggunakan kuesioner pengetahuan gizi dan semi-quantitative food frequency questionnaire . Jumlah sampel 158 orang dari angkatan 2018, 2019, dan 2020 yang memenuhi kriteria inklusi. Teknik pengambilan sampel menggunakan stratified random sampling. Analisis data secara univariat dan bivariat menggunakan uji chi square. Hasil penelitian terdapat 99 (62,6%) responden memiliki pengetahuan gizi cukup. Pola konsumsi baik sebanyak 64 (40,5%) responden, sedangkan pola konsumsi kurang baik sebanyak 94 (59,4%%) responden. Sebagian besar responden memiliki status gizi normal yaitu sebanyak 123(77,8%). Kesimpulan penelitian ini tidak ada hubungan antara pengetahuan gizi dan pola konsumsi dengan status gizi pada mahasiswa Fakultas Kedokteran Universitas Nusa Cendana.
Hubungan Tingkat Pengetahuan dengan Partisipasi Vaksinasi COVID-19 di Puskesmas Betun Kabupaten Malaka Kehi Lau, Cindy Anna Maria; Koamesah, Sangguana Marthen Jacobus; Sagita, Sidarta; ningsih, Iswa
Cendana Medical Journal Vol 10 No 2 (2022): Cendana Medical Journal
Publisher : Universitas Nusa Cendana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35508/cmj.v10i2.9058

Abstract

Background : The Corona Virus Disease 2019 pandemic is a health problem that is currently in the world's spotlight. COVID-19 has been designated by the Indonesian government as a non-natural disaster and has received attention from health scientists and the general public. Since January 2021, the government has carried out vaccinations in stages while remaining disciplined in health protocols. Evaluation of effectiveness proves that vaccines are able to reduce the risk of being infected with COVID-19, as well as reduce treatment and death for the residents. COVID-19 vaccination aims to reduce the transmission of COVID-19 between the residents and is expected to achieve herd immunity. Public knowledge of COVID-19 and vaccines can support the success of this disease management program. Based on the results of a vaccine acceptance survey conducted by the Ministry of Health, ITAGI, UNICEF and WHO, around 30% of their respondents expressed concerns about the safety and effectiveness of vaccines, expressed distrust of vaccines, and questioned the halalness of vaccines because the coverage of vaccine information provision in Indonesia has not been maximized because it is still new and there are mutations from the coronavirus. Objective : This study aims to determine whether there is a relationship between the level of knowledge and the participation of COVID-19 vaccination at the Betun Health Center, Malaka Regency. Method : This study used an analytical observational research design with a cross sectional design. Samples were choosen using a non-probability sampling technique with a type of consecutive sampling with a total sample of 100 people. The data were collected using a questionnaire on Knowledge of COVID-19 Vaccination Participation to the visitors of Betun Health Center, Malaka Regency. The data analysis used is the Chi-Square test. Result : From the test results using the chi-square test, there was a significant correlation between the level of knowledge with the participation of COVID-19 vaccination at the Betun Health Center, Malaka Regency with the p value = 0.005. Conclusion : There is a significant correlation between the level of knowledge with the participation of COVID-19 vaccination at the Betun Health Center, Malaka Regency. Keywords : Level of knowledge, participation, vaccination
Relationship Of Mother's Knowlwdge To Children's Immunization Status In The Work Area Of Sikumana Healt Center Wea, Aulia Rahmah; Wungouw, Herman Pieter L; Telussa, Arley Sadra; Koamesah, Sangguana Marthen Jacobus
Cendana Medical Journal Vol 10 No 2 (2022): Cendana Medical Journal
Publisher : Universitas Nusa Cendana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35508/cmj.v10i2.9096

Abstract

HUBUNGAN PENGETAHUAN IBU TERHADAP STATUS lMUNISASI ANAK DIWILAYAH KERJA PUSKESMAS SIKUMANA Aulia Rahmah Wea 1, Herman Pieter Louis Wungouw2, Arley Sadra Telussa 3, S.M.J. Koamesah 4 1 Fakultas Kedokteran dan Kedokteran Hewan Universitas Nusa Cendana 2Departemen Radiologi Fakultas Kedokteran dan Kedokteran Hewan Universitas Nusa Cendana 3Departemen Urologi Fakultas Kedokteran dan Kedokteran Hewan Universitas Nusa Cendana 4Departemen Ilmu Kesehatan Masyarakat dan Ilmu Kedokteran Komunitas Fakultas Kedokteran dan Kedokteran Hewan Universitas Nusa Cendana ABSTRAK Latar Belakang: Imunisasi adalah upaya meningkatkan kekebalan tubuh terhadap penyakit. Menurut WHO sekitar 1,5 juta anak mengalami kematian tiap tahunnya karena penyakit yang dapat dicegah dengan imunisasi.Tinggi rendahnya tingkat pengetahuan ibu tentang pentingnya imunisasi bagi anak akan berperan dalam mempengaruhi perilaku orang tua untuk ikut serta dalam kegiatan imunisasi. Tujuan: Penelitian ini bertujuan untuk mengetahui hubungan antara tingkat pengetahuan ibu dan status imunisasi dasar anak di Puskesmas Sikumana Kota Kupang Metode: Penelitian ini menggunakan metode observasional analitik dengan rancangan pendekatan cross-sectional yang dilakukan pada ibu dengan bayi berusia tiga bulan sampai 9 bulan di wilayah kerja Puskesmas Sikumana Kota Kupang. Teknik pengambilan sampel adalah accidental sampling dengan jumlah sampel sebanyak 57 responden. Data pengetahuan ibu diperoleh dari pengisisan kuesioner dan data kelengkapan imunisasi diperoleh dari Kartu Menuju Sehat (KMS) anak. Data akan dianalisis secara univariat dan bivariat menggunakan Uji Chi-Square. Hasil: Penelitian terhadap 57 responden memberikan gambaran tentang status pengetahuan: 11 responden baik, 28 responden cukup, dan 18 responden kurang, serta gambaran tentang status imunisasi: 30 anak lengkap dan 27 tidak lengkap. Hasil anlisis bivariat uji Chi-Square memperoleh hasil P = 0.007 (P>0.05) Kesimpulan: Terdapat hubungan yang signifikan antara tingkat pengetahuan ibu dan status imunisasi dasar anak di wilayah kerja Puskesmas Sikumana. Kata Kunci: Pengetahuan, Status Imunisasi, Puskesmas Sikumana.
Hubungan Tingkat Pengetahuan Ibu Hamil Tentang COVID-19 Dengan Tingkat Kecemasan Selama Kehamilan Masa Pandemi Pada Puskesmas di Kota Kupang Sidauruk, Debora Maryke Idawati; Koamesah, Sangguana Marthen Jacobus; Nurina, Rr. Listyawati; Ratu, Kristian
Cendana Medical Journal Vol 11 No 1 (2023): Cendana Medical Journal
Publisher : Universitas Nusa Cendana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35508/cmj.v11i1.10585

Abstract

ABSTRACTBackground : Coronavirus Disease 2019 (COVID-19) is an infection of the SARS- CoV-2 virus in the respiratory tract that has spread to various regions of the country and has been declared a global pandemic. The COVID-19 virus can infect anyone, including pregnant women as a special group that is susceptible to infection with the virus. During pregnancy, the pregnant woman experiences many physiological and psychological changes that bring discomfort and cause anxiety. Before the pandemic, pregnant women experienced anxiety related to preparation for childbirth, lack of family support, etc. During the COVID-19 pandemic, pregnant women anxiety have increased because they are faced with a lot of concerns related to the health of the pregnant woman herself, the fetus, and her family. In addition, too many information from various media about COVID-19 and pregnant women's lack of knowledge about transformations during pregnancy are also causes anxiety for pregnant women. Knowledge owned by pregnant women about pregnancy during the COVID-19 pandemic can be a future reference for how pregnant women behave in facing and overcoming anxiety related to COVID-19 Objective : This study aims to determine the correlation between pregnant women’s level of knowledge about COVID-19 and the level of anxiety in pregnancy during a pandemic at the Community Health Center in Kupang City.Method : This study used an analytic observational research design with a cross- sectional design. Sampling using probability sampling technique, which is stratified random sampling with total sample about 105 people. Data was accumulated by using Pregnant Women's Knowledge about COVID-19 Questionnair and the Hamilton Anxiety Rating Scale questionnaire that had given to pregnant women at the health center in Kupang City. The data were analyzed by using Spearman Rank test.Result : The results after using the Spearman rank test, there is a significant corrrelation between the pregnant women’s level of knowledge about COVID-19 and pregnancy level of anxiety during pandemic at health centers in Kupang City with p value= 0.007. Conclusion : There is a significant correlation between the pregnant women’s level of knowledge about COVID-19 and pregnancy level of anxiety during pandemic at health centers in Kupang City.Keywords : Level of knowledge, level of anxiety
Hubungan Tingkat Pengetahuan dengan Self Efficacy Vaksinasi COVID-19 di Puskesmas Tarus Kabupaten Kupang Sumbayak, Anastasia Emma Reinaita; Koamesah, Sangguana Marthen Jacobus; Pakan, Prisca Deviani; Sagita, Sidarta
Cendana Medical Journal Vol 11 No 1 (2023): Cendana Medical Journal
Publisher : Universitas Nusa Cendana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35508/cmj.v11i1.10590

Abstract

Background : The 2019 Corona Virus Disease pandemic is still a concern until today. The virus that causes COVID-19 can keep mutating and producing new variants over time. The government has attempted various health protocols including a national vaccination program, with the aim of forming herd immunity. Vaccination has 2 stages of primary vaccination and additional or booster dose of vaccination. Based on data from the Ministry of Health as of 19 January 2022, Kupang Regency has the lowest vaccination rate in East Nusa Tenggara. This can be caused by a lack of self efficacy or belief in receiving the COVID-19 vaccine. Several survey results show that people’s refusal and doubts about receiving vaccinations are due to concerns about the safety and effectiveness as well as the side effect of COVID-19 vaccine, which can be caused by lack of knowledge about the COVID-19 vaccination. Objective : This study aims to determine whether there is a relationship between the level of knowledge and self efficacy of COVID-19 vaccination at the Tarus Health Center, Kupang Regency. Method : This study used an analytical observational research design with a cross sectional design. Samples were choosen using a non-probability sampling technique with a type of consecutive sampling with a total sample of 103 people. The data were collected using a questionnaire on Knowledge of COVID-19 Vaccination and Self Efficacy of COVID-19 Vaccination to the visitors of Tarus Health Center, Kupang Regency. The data analysis used is the Rank Spearmen Correlation test. Result : From the test results using the Rank Spearman Correlation test, there was no significant correlation between the level of knowledge with the self efficacy of COVID-19 vaccination at the Tarus Health Center, Kupang Regency with the sig(2-tailed) > 0.005. Conclusion : There is no significant correlation between the level of knowledge with the self efficacy of COVID-19 vaccination at the Tarus Health Center, Kupang Regency.
Hubungan Konsumsi Makanan Berserat dengan Pola Defekasi pada Siswa SMA Negeri 1 Taebenu Fahri, Rifka Annisa; Wungouw, Herman Pieter Pieter Louis; Woda, Rahel Rara; Koamesah, Sangguana Marthen Jacobus
Cendana Medical Journal Vol 11 No 1 (2023): Cendana Medical Journal
Publisher : Universitas Nusa Cendana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35508/cmj.v11i1.10719

Abstract

Latar Belakang : Serat merupakan bagian dari tumbuhan yang dapat dikonsumsi dan tersusun dari karbohidrat, memiliki sifat resistan terhadap proses pencernaan dan penyerapan di usus halus manusia serta mengalami fermentasi sebagian atau keseluruhan di usus besar. Sumber serat paling mudah ditemukan dalam sayuran dan buah-buahan. Salah satu fungsi serat adalah menyehatkan saluran cerna, Hal ini mendorong konsumsi serat makanan menjadi suatu kebutuhan yang harus dipenuhi karena serat dapat membantu memelihara kesehatan. Kebutuhan serat yang dianjurkan berdasarkan Angka Kecukupan Gizi (AKG) untuk remaja usia 16-18 tahun adalah 29 g/hari sampai 37 g/hari. Asupan serat dalam makanan yang dikonsumsi, dapat mempengaruhi pola defekasi. Apabila konsumsi serat dalam makanan tidak terpenuhi maka akan menimbulkan gangguan di saluran pencernaan yaitu konstipasi. Pada usia remaja, dapat terjadi konstipasi, salah satu penyebab dikarenakan pola makan remaja yaitu kurang serat. Tujuan Penelitian : Penelitian ini bertujuan untuk mengetahui bagaimana hubungan antara konsumsi makanan berserat dengan pola defekasi pada Siswa SMAN 1 Taebenu. Metode Penelitian : Penelitian ini menggunakan desain penelitian observasional analitik dengan rancangan cross sectional. Pengambilan sampel menggunakan teknik proportionate stratified random sampling dengan jumlah sampel sebanyak 86 orang. Pengumpulan data konsumsi serat menggunakan Formulir Food Recall 24 jam di ambil 2 hari tidak berturut-turut dan pola defekasi menggunakan kuesioner catatan pola defekasi disertai bristol stool chart untuk analisis data yang digunakan uji korelasi Rank Spearman’s Hasil : Dari hasil uji menggunakan uji korelasi Rank Spearman’s , terdapat hubungan yang signifikan antara konsumsi serat dengan konsistensi feses atau p<0,05. Tidak terdapat hubungan yang signifikan antara konsumsi serat dengan frekuensi defekasi dan nyeri saat defekasi atau p>0,05 Kesimpulan : Adanya hubungan yang signifikan antara konsumsi serat dengan konsistensi feses tetapi tidak terdapat hubungan yang signifikan antara konsumsi serat dengan frekuensi defekasi dan nyeri saat defekasi
The The Correlation of Personal Hygiene Behavior on The Incidence of Dandruff (Pityriasis sicca) in Adolescents Living in Orphanages in Kelapa Lima Sub-District, Kupang City ., Veronica; Koamesah, Sangguana Marthen Jacobus; Hutasoit, Regina Marvina; Folamauk, Conrad Liab Hendricson
Cendana Medical Journal Vol 13 No 1 (2025): Cendana Medical Journal
Publisher : Universitas Nusa Cendana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35508/cmj.v13i1.23565

Abstract

Background: Dandruff is a condition of exfoliation of the corneum layer of the scalp forming white flakes, which is most common in adolescents because the sebaceous glands actively produce sebum causing increased colonization of Malassezia sp. yeast, the cause of dandruff. A factor that influences the incidence of dandruff is personal hygiene behavior. Adolescents in orphanages have a high risk of experiencing dandruff due to poor personal hygiene behavior, one of which is the use of personal items alternating to fellow friends. Objective: To determine whether there is a correlation between personal hygiene behavior and the incidence of dandruff (Pityriasis sicca) in adolescents living in orphanages in Kelapa Lima Sub-District, Kupang City. Methods: This study used an observational analytic research design with a cross-sectional study design. Respondents were selected by purposive sampling method according to the inclusion and exclusion criteria by taking the minimum number of respondents using the Lemeshow formula so that 55 respondents were obtained. Data collection using personal hygiene behavior questionnaire and wood lamp inspection. Data analysis using the fisher exact test. Results: The correlation between personal hygiene behavior and the incidence of dandruff obtained p-value = 0.223 (p>0.05) with fisher exact test, so it does not have a significant correlation. Two items of personal hygiene behavior on the questionnaire, namely the use of sleeping pillows alone / changing with others has a p-value = 0.007 (p < 0.05), and shampooing after completing outdoor activities and long-term exposure to polluting dust has a p-value = 0.016, so it has a significant correlation with the incidence of dandruff. Conclusion: There is no significant correlation between personal hygiene behavior and the incidence of dandruff in adolescents living in orphanages in Kelapa Lima District, Kupang City.
Latrine Ownership and Soil-Transmitted Helminth Infection in a Rural Indonesian Setting: A Cross-Sectional Study from Mataredi, Central Sumba Sabawali, Jeremias Awang Bagas; Deo, Dwita Anastasia; Koamesah, Sangguana Marthen Jacobus; Buntoro, Ika Febianti
Jurnal Biologi Tropis Vol. 25 No. 4a (2025): Special Issue
Publisher : Biology Education Study Program, Faculty of Teacher Training and Education, University of Mataram, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jbt.v25i4a.11160

Abstract

Soil-transmitted helminth (STH) infection remains a public health concern in rural tropical settings, where limited sanitation and high environmental exposure elevate risk. In Mataredi Village, most residents are subsistence farmers with constrained access to improved sanitation. Objective to estimate the prevalence of STH infection and assess its association with household latrine ownership in Mataredi Village, Katikutana District, Central Sumba. Methods: An analytical cross-sectional study was conducted in June–July 2024. A total of 144 residents aged >5 years who met inclusion criteria were enrolled using consecutive sampling. Fresh stool samples were examined by direct smear with 2% Lugol’s iodine. The association between latrine ownership (yes/no) and STH infection status (positive/negative) was evaluated using the Chi-square test; results are presented as p-value and odds ratio (OR) with 95% confidence interval (CI). Overall prevalence of STH infection was 19.4% (28/144). The species profile was dominated by Trichuris trichiura, with both single and mixed infections detected. Based on the Chi-square test, there was no statistically significant association between latrine ownership and STH infection (p = 0.943; OR 0.88; 95% CI 0.38–2.06). A mass deworming campaign conducted in May 2024 may have reduced detectable worm burden and attenuated observed associations.  The prevalence of STH infection in Mataredi Village was 19.4%, with Trichuris trichiura predominance. No significant association was found between household latrine ownership and infection status.
The Relationship between PROLANIS Exercise Routine and Quality of Life in Hypertensive Patients in Puskesmas Oesapa, Kupang City Wijoyo, Adinda Savely Kend Amara; Koamesah, Sangguana Marthen Jacobus; Wungouw, Herman Pieter Louis; Handoyo, Nicholas Edwin
Jurnal Biologi Tropis Vol. 25 No. 4a (2025): Special Issue
Publisher : Biology Education Study Program, Faculty of Teacher Training and Education, University of Mataram, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jbt.v25i4a.11170

Abstract

Hypertension is one of the leading causes of premature death worldwide, including in Indonesia. East Nusa Tenggara Province (NTT) has a high prevalence of hypertension, yet awareness and treatment rates remain low. In Kupang City, Puskesmas Oesapa reports the highest number of hypertension cases. PROLANIS exercise, a non-pharmacological intervention, is considered effective in improving patients quality of life. This study aims to determine the relationship between PROLANIS exercise routine and quality of life of hypertensive patients in the working area of Puskesmas Oesapa. Objective: To investigate the association between the routine participation in PROLANIS exercise and the quality of life of hypertensive patients in working area of Puskesmas Oesapa. Methods: This study used an analytical observational design with a cross-sectional approach. Data were collected through medical records and questionnaires, including medication adherence and the WHOQOL-BREF instrument. Sampling was conducted using total sampling technique and analyzed using Spearman correlation test. Results: The results showed a significant relationship between PROLANIS exercise routine and the quality of life of hypertensive patients, with a p-value of 0.041 (p < 0.05). Conclusion: A higher frequency of PROLANIS exercise is associated with better quality of life in hypertensive patients. Therefore, promoting regular participation in PROLANIS exercise should be considered as a strategy to improve the quality of life in this population.
Co-Authors ., Veronica Arley Sadra Telussa Balbesi, Patrick David Altissimo Charina, Maria Selviana Damanik, Efrisca M. Br. Dwita Anastasia Deo Fahri, Rifka Annisa Folamauk, Conrad Liab Hendricson Hutasoit, Regina M. Hutasoit, Regina Marvina Ika Febianti Buntoro Kehi Lau, Cindy Anna Maria Muntasir, Muntasir Nicholas Edwin Handoyo ningsih, Iswa Nurina, Rr. Listyawati PAKAN, PRISCA DEVIANI Ratu, Kristian Sabawali, Jeremias Awang Bagas Sagita, Sidarta Sidauruk, Debora Maryke Idawati Sumbayak, Anastasia Emma Reinaita Wea, Aulia Rahmah Wijoyo, Adinda Savely Kend Amara Woda, Rahel Rara Wungouw, Herman Pieter L Wungouw, Herman Pieter Louis Wungouw, Herman Pieter Pieter Louis