Penerapan Model Pembelajaran Kooperatif Tipe Student Team Achievement Division (Stad) Terhadap Hasil Belajar Siswa Pada Materi Sistem Pencernaan Manusia Di Kelas VIII Sekolah Menengah Pertama Negeri 5 Nanga Kayan

Penelitian ini bertujuan untuk mengetahui penerapan model pembelajaran kooperatif tipe STAD terhadap hasil belajar siswa pada materi sistem pencernaan manusia di kelas VIII. Metode penelitian yang digunakan adalah kuantitatif deskriptif dengan bentuk penelitian pre eksperimen dan desain one group pretest-postest. Pengumpulan data dilakukan melalui tes awal dan tes akhir pembelajaran untuk mengetahui hasil belajar siswa. Selain itu data lainnya adalah angket respon siswa. Rerata hasil belajar siswa sebelum penelitian adalah 53.57 dengan kategori rendah dan setelah pelansanaan penelitian adalah 76.19 dengan kategori tinggi dan tingkat ketuntasan klasikal 85.71 % serta indeks gain 0.49 (sedang). Tanggapan siswa terhadap model pembelajaran kooperatif tipe STAD sangat kuat (88.57%). Hasil uji hipotesis diperoleh thitung > ttabel (11.41 > 2.086) yang berarti hipotesis Ha diterima. Kesimpulan dari penelitian ini adalah model pembelajaran Kooperatif tipe STAD berpengaruh signifikan terhadap hasil belajar siswa pada materi sistem pencernaan manusia di kelas VIII SMP Ngeri 5 Nanga Kayan

Efektivitas Model Pembelajaran Inkuiri terhadap Keterampilan Proses Sains Siswa pada Materi Sel di Kelas XI IPA

Penelitian ini bertujuan untuk mengetahui Efektivitas Model Pembelajaran Inkuiri terhadap Keterampilan Proses Sains pada Materi Sel. Variabel dalam penelitian ini ada dua yaitu variabel bebas “model pembelajaran inkuiri” dan variabel terikat “keterampilan proses sains”. Metode yang digunakan dalam penelitian ini adalah metode kuantitatif deskriptif. Bentuk penelitian yang digunakan yaitu Quasy-exsperiment dengan desain penelitian Nonequivalent Control Group Design. Teknik pengambilan sampelnya menggunakan teknik Purposive Sampling. Teknik pengumpulan data menggunakan teknik pengukuran. Alat pengumpulan data yang digunakan adalah soal tes. Berdasarkan perhitungan hasil belajar siswa diperoleh nilai rata-rata pretest 61,6 untuk kelas eksperimen dan 61,90 untuk kelas kontrol serta nilai rata-rata posttest 78,9 untuk kelas eksperimen dan 71,14 untuk kelas kontrol. Peningkatan Keterampilan proses sains siswa dihitung dengan rumus N – Gains kelas eksperimen didapatkan hasil nilai rata-rata N – Gains sebesar 0,45 masuk kategori “Sedang” dan pada kelas kontrol didapatkan hasil nilai rata-rata N – Gain sebesar 0,25 masuk kategori “Rendah”. Teknik pengolahan data menggunakan Uji U Mann Whitney pada data pretest, karena pada kelas kontrol pretest data berdistribusi tidak normal, sedangkan pada data postest menggunakan Uji T karena jumlah siswa 30 orang pada kelas eksperimen dan 29 orang pada kelas kontrol dan kedua data postest berdistribusi normal serta homogen. Pada hasil pretest diketahui bahwa nilai Zhitung adalah -0,106 sedangkan nilai Ztabel pada a = 5% adalah ±1,96. Sehingga dapat disimpulkan bahwa -1,96 ≤ -0,106 ≤ 1,96 maka yang diterima yaitu Ho yang artinya tidak terdapat perbedaan yang signifikan keterampilan proses sains siswa pada materi sel antara siswa pada kelas kontrol dengan kelas eksperimen sebelum pembelajaran (pretest). Pada hasil postest diketahui bahwa nilai thitung adalah 3,21 sedangkan nilai ttabel pada α = 5% dengan db (N1 + N2 – 2 = 57) adalah 2,00. Hal ini berarti nilai thitung > ttabel (3,21 > 2,00) maka Ha diterima yang artinya terdapat perbedaan yang signifikan keterampilan proses sains siswa pada materi sel antara siswa pada kelas kontrol dengan metode konvensional dan kelas eksperimen dengan menggunakan model pembelajaran inkuiri. Efektivitas model pembelajaran inkuiri 0,78 kategori Rendah

Pengaruh Model Pembelajaran Kooperatif Tipe Cooperative, Integrated, Reading, and Composition Berbasis Media Peta Konsep Terhadap Kemampuan Berpikir Kritis Siswa Pada Materi Sistem Pencernaan Manusia

Kemampuan berpikir kritis siswa merupakan salah satu indikator keberhasilan belajar. Agar kemampuan berpikir kritis siswa dapat meningkat diperlukan strategi pembelajaran dengan menggunakan model maupun media pembelajaran salah satunya yaitu model pembelajaran CIRC (Cooperative, Integrated, Reading, and Composition) berbasis media peta konsep rantai kejadian. Penelitian ini dilakukan untuk mengetahui pengaruh model CIRC (Cooperative, Integrated, Reading, and Composition) berbasis media peta konsep rantai kejadian terhadap peningkatan kemampuan berpikir kritis siswa kelas VIII SMP Negeri 3 Sintang pada materi sistem pencernaan manusia. Pendekatan dalam penelitian ini berupa pendekatan kuantitatif dengan bentuk penelitian Quasi Eksperimental Design. Populasi pada penelitian ini adalah seluruh siswa kelas VIII SMP Negeri 3 Sungai Tebelian terdiri dari 142siswa. Teknik pengambilan sampel menggunakan teknik purposive sampling dengan total sampel 48 siswa, 24siswa untuk kelas eksperimen dan 24 siswa untuk kelas kontrol. Teknik pengumpulan data menggunakan teknik observasi lansung, teknik pengukuran, dan teknik komunikasi tidak langsung. Instrumen untuk mengukur kemampuan berpikir kritis siswa berupa essay sebanyak 8 item. Berdasarkan uji hipotesis pada posttest kelas eksperimen dan kelas kontrol diperoleh nilai sig. (2–tailed) sebesar 0,00 dan α = 0,05. Pengujian hipotesis membuktikan bahwa nilai sig. (2–tailed)< α (0,00 < 0,05) yang artinya Hoditolak dan H1 diterima, yakni terdapat perbedaan hasil kemampuan berpikir kritis siswa antara kelas eksperimen dan kelas kontrol pada pengukuran akhir posttest

Plastron properties of a superhydrophobic surface

Most insects and spiders drown when submerged during flooding or tidal inundation, but some are able to survive and others can remain submerged indefinitely without harm. Many achieve this by natural adaptations to their surface morphology to trap films of air, creating plastrons which fix the water-vapor interface and provide an incompressible oxygen-carbon dioxide exchange surface. Here the authors demonstrate how the surface of an extremely water-repellent foam mimics this mechanism of underwater respiration and allows direct extraction of oxygen from aerated water. The biomimetic principle demonstrated can be applied to a wide variety of man-made superhydrophobic materials

Developmental Immunotoxicity Testing and Protection of Children's Health

Dietert discusses a new study in PLoS Medicine, by Heilmann et al., showing that children exposed to polychlorinated biphenyls (PCBs) have reduced antibody responses to childhood vaccinations

Differences in early developmental rate and yolk conversion efficiency in offspring of trout with alternative life histories

Partial migration, in which some individuals of a population migrate while other individuals remain resident, is generally associated with ontogenetic shifts to better feeding areas or as a response to environmental instability, but its underlying mechanisms remain relatively unknown. Brown trout (Salmo trutta) exhibit partial migration, with some individuals remaining in fresh water (freshwater-resident) while others undertake an anadromous migration, where they spend time at sea before returning to breed in fresh water (migrant). We reared full-sibling groups of offspring from freshwater-resident and anadromous brown trout from the same catchment in the laboratory under common garden conditions to examine potential differences in their early development. Freshwater-resident parents produced eggs that were slower to hatch than those of anadromous parents, but freshwater-resident offspring were quicker to absorb their yolk and reach the stage of exogenous feeding. Their offspring also had a higher conversion efficiency from the egg stage to the start of exogenous feeding (so were larger by the start of the fry stage) than did offspring from anadromous parents despite no difference in standard metabolic rate, maximal metabolic rate, or aerobic scope. Given these differences in early development we discuss how the migration history of the parents might influence the migration probability of the offspring

Delirium screening in an acute care setting with a machine learning classifier based on routinely collected nursing data: A model development study

Delirium screening in acute care settings is a resource intensive process with frequent deviations from screening protocols. A predictive model relying only on daily collected nursing data for delirium screening could expand the populations covered by such screening programs. Here, we present the results of the development and validation of a series of machine-learning based delirium prediction models. For this purpose, we used data of all patients 18 years or older which were hospitalized for more than a day between January 1, 2014, and December 31, 2018, at a single tertiary teaching hospital in Zurich, Switzerland. A total of 48,840 patients met inclusion criteria. 18,873 (38.6%) were excluded due to missing data. Mean age (SD) of the included 29,967 patients was 71.1 (12.2) years and 12,231 (40.8%) were women. Delirium was assessed with the Delirium Observation Scale (DOS) with a total score of 3 or greater indicating that a patient is at risk for delirium. Additional measures included structured data collected for nursing process planning and demographic characteristics. The performance of the machine learning models was assessed using the area under the receiver operating characteristic curve (AUC). The training set consisted of 21,147 patients (mean age 71.1 (12.1) years; 8,630 (40.8%) women|) including 233,024 observations with 16,167 (6.9%) positive DOS screens. The test set comprised 8,820 patients (median age 71.1 (12.4) years; 3,601 (40.8%) women) with 91,026 observations with 5,445 (6.0%) positive DOS screens. Overall, the gradient boosting machine model performed best with an AUC of 0.933 (95% CI, 0.929 - 0.936). In conclusion, machine learning models based only on structured nursing data can reliably predict patients at risk for delirium in an acute care setting. Prediction models, using existing data collection processes, could reduce the resources required for delirium screening procedures in clinical practice

Prenatal Vitamin D Supplementation and Child Respiratory Health: A Randomised Controlled Trial

PMCID: PMC3691177This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Topography and instability of monolayers near domain boundaries

We theoretically study the topography of a biphasic surfactant monolayer in the vicinity of domain boundaries. The differing elastic properties of the two phases generally lead to a nonflat topography of ``mesas'', where domains of one phase are elevated with respect to the other phase. The mesas are steep but low, having heights of up to 10 nm. As the monolayer is laterally compressed, the mesas develop overhangs and eventually become unstable at a surface tension of about K(dc)^2 (dc being the difference in spontaneous curvature and K a bending modulus). In addition, the boundary is found to undergo a topography-induced rippling instability upon compression, if its line tension is smaller than about K(dc). The effect of diffuse boundaries on these features and the topographic behavior near a critical point are also examined. We discuss the relevance of our findings to several experimental observations related to surfactant monolayers: (i) small topographic features recently found near domain boundaries; (ii) folding behavior observed in mixed phospholipid monolayers and model lung surfactants; (iii) roughening of domain boundaries seen under lateral compression; (iv) the absence of biphasic structures in tensionless surfactant films.Comment: 17 pages, 9 figures, using RevTeX and epsf, submitted to Phys Rev