89 research outputs found
PENERAPAN PEMBELAJARAN CONTEXTUAL TEACHING AND LEARNING (CTL) TERHADAP HASIL BELAJAR SISWA PADA POKOK BAHASAN CARA-CARA PENANGANAN LIMBAH DI SMK CARUBAN NAGARI KECAMATAN DUKUPUNTANG KABUPATEN CIREBON
JUBAEDAH : Penerapan Pembelajaran Contexstual Teaching And Learning (CTL) Terhadap Hasil Belajar Siswa Pada Pokok Bahasan Cara-Cara Penanganan Limbah Di SMK Caruban Nagari Kecamatan Dukupuntang Kabupaten Cirebon. Proses pembelajaran Contexstual Teaching and Learning (CTL) merupakan pembelajaran yang membantu guru antara materi yang diajarkan dengan situasi dunia nyata siswa dan mendorong siswa membuat hubungan antara pengetahuan yang dimiliki dengan penerapannya dalam kehidupannya sebagai anggota keluarga dan masyarakat. Dengan pemahaman ini, hasil belajar diharapkan lebih bermakna bagi siswa. Untuk mengatasi masalah tersebut, seorang guru dapat menggunakan pembelajaran Contexstual Teaching and Learning (CTL) dalam menyampaikan materi khususnya IPA (Ilmu Pengetahuan Alam). Penelitian ini bertujuan untuk mengkaji bagaimana penerapan pembelajaran dengan menggunakan contextual teaching and learning (CTL) terhadap hasil belajar siswa pada pokok bahasan cara-cara penanganan limbah di SMK Caruban Nagari Kecamatan Dukupuntang Kabupaten Cirebon.Untuk mengkaji apakah ada perbedaan hasil belajar yang menggunakan contextual teaching and learning (CTL) dan pembelajaran tidak menggunakan contextual teaching and learning (CTL) terhadap hasil belajar siswa antara kelas eksperimen dengan kelas kontrol pada pokok bahasan cara-cara penanganan limbah.Untuk mengkaji bagaimana respon siswa terhadap penerapan pembelajaran contextual teaching and learning (CTL) pada pokok bahasan cara-cara penanganan. Populasi dalam penelitian ini adalah seluruh siswa SMK Caruban Nagari Kecamatan Dukupuntang Kabupaten Cirebon. Adapun sampel dalam penelitian ini yakni diambil kelas XIa sebagai kelas kontrol dan kelas XI b eksperimen dalam penelitian dan masing-masing kelas berjumlah 30 siswa. Dalam pengumpulan data, penulis menggunakan teknik tes, angket dan observasi. Setelah data diperoleh dari hasil penelitian maka data tersebut dianalisis dengan cara analisis kuantitaf, sebelum penulis melakukan uji instrumen untuk memperoleh validitas menggunkan master templet. Kesimpulam dari penelitian ini menunjukkan bahwa dalam proses pembelajaran yang dilakukan dalam kelas dengan menggunakan Contexstual Teaching and Learning (CTL) mendapat nilai minimum 11 mengalami peningkatan sampai nilai 19 dengan nilai rata-rata 21.13. Hal ini dapat dilihat dari pada gain dari tiap kelas. Dari data yang diperoleh dari gain menunjukan bahwa nilai t diperoleh sebesar = -6,323 dengan derajat kebebasan (df) = n1 + n2 – 2 = (30 + 30 – 2 =58 ).α = 0,05 diperoleh Sig.0,000. karena Sig.0,000 < 0,05 maka dapat disimpulkan bahwa Ha diterima. Respon siswa terhadap penerapan pembelajaran contextual teaching and learning (CTL) yang menjawab ya sebesar 49 % termasuk kriteria cukup, yang menjawab kadang-kadang sebesar 39% kriteria rendah dan yang menjawab tidak sedikit sekali 12% termasuk kriteria rendah sekali
Improving Chlorophyll-a Estimation from Sentinel-2 (MSI) in the Barents Sea using Machine Learning
This article addresses methodologies for remote sensing of ocean Chlorophyll-a (Chl-a), with emphasis on the Barents Sea. We aim at improving the monitoring capacity by integrating in situ Chl-a observations and optical remote sensing to locally train machine learning (ML) models. For this purpose, in situ measurements of Chl-a ranging from 0.014–10.81 mg/m 3 , collected for the years 2016–2018, were used to train and validate models. To accurately estimate Chl-a, we propose to use additional information on pigment content within the productive column by matching the depth-integrated Chl-a concentrations with the satellite data. Using the optical images captured by the multispectral imager instrument on Sentinel-2 and the in situ measurements, a new spatial window-based match-up dataset creation method is proposed to increase the number of match-ups and hence improve the training of the ML models. The match-ups are then filtered to eliminate erroneous samples based on the spectral distribution of the remotely sensed reflectance. In addition, we design and implement a neural network model dubbed as the ocean color net (OCN), that has performed better than existing ML-based techniques, including the Gaussian process Regression (GPR), regionally tuned empirical techniques, including the ocean color (OC3) algorithm and the spectral band ratios, as well as the globally trained Case-2 regional/coast colour (C2RCC) processing chain model C2RCC-networks. The proposed OCN model achieved reduced mean absolute error compared to the GPR by 5.2%, C2RCC by 51.7%, OC3 by 22.6%, and spectral band ratios by 29%. Moreover, the proposed spatial window and depth-integrated match-up creation techniques improved the performance of the proposed OCN by 57%, GPR by 41.9%, OC3 by 5.3%, and spectral band ratio method by 24% in terms of RMSE compared to the conventional match-up selection approach
Vertical fluxes of nitrate in the seasonal nitracline of the Atlantic sector of the Arctic Ocean
Source at http://dx.doi.org/10.1002/2016JC011779 This study compiles colocated oceanic observations of high-resolution vertical profiles of nitrate concentration and turbulent microstructure around the Svalbard shelf slope, covering both the permanently ice-free Fram Strait and the pack ice north of Svalbard. The authors present an overview over the seasonal evolution of the distribution of nitrate and its relation to upper ocean stratification. The average upward turbulent diffusive nitrate flux across the seasonal nitracline during the Arctic summer season is derived, with average values of 0.3 and 0.7 mmol m−2 d−1 for stations with and without ice cover, respectively. The increase under ice-free conditions is attributed to different patterns of stratification under sea ice versus open water. The nitrate flux obtained from microstructure measurements lacked a seasonal signal. However, bottle incubations indicate that August nitrate uptake was reduced by more than an order of magnitude relative to the May values. It remains inconclusive whether the new production was limited by an unidentified factor other than NO3− supply in late summer, or the uptake was underestimated by the incubation method.</p
Seasonality of vertical flux and sinking particle characteristics in an ice-free high arctic fjord—Different from subarctic fjords?
Source: http://dx.doi.org/10.1016/j.jmarsys.2015.10.003
A manuscript version of this article is part of Ingrid Wiedmann's doctoral thesis, which is available in Munin at http://hdl.handle.net/10037/8293The arctic Adventfjorden (78°N, 15°E, Svalbard) used to be seasonally ice-covered but has mostly been ice-free
since 2007. We used this ice-free arctic fjord as a model area to investigate (1) how the vertical
fl
ux of biomass
(chlorophyll
a
and particulate organic carbon, POC) follows the seasonality of suspended material, (2) how sink-
ing particle characteristics change seasonally and affect the vertical
fl
ux, and (3) if the vertical
fl
ux in the ice-free
arctic fjord with glacial runoff resembles the
fl
ux in subarctic ice-free fjords. During seven
fi
eld investigations
(December 2011
–
September 2012), suspended biomass was determined (5, 15, 25, and 60 m), and short-term
sediment traps were deployed (20, 30, 40, and 60 m), partly modi
fi
ed with gel-
fi
lled jars to study the size and
frequency distribution of sinking particles. During winter, resuspension from the sea
fl
oor resulted in large,
detrital sinking particles. Intense sedimentation of fresh biomass occurred during the spring bloom. The highest
POC
fl
ux was found during autumn (770
–
1530 mg POC m
−
2
d
−
1
), associated with sediment-loaded glacial
runoff and high pteropod abundances. The vertical biomass
fl
ux in the ice-free arctic Adventfjorden thus resem-
bled that in subarctic fjords during winter and spring, but a higher POC sedimentation was observed during
autumn
Arctic in Rapid Transition (ART) : science plan
The Arctic is undergoing rapid transformations that have brought the Arctic Ocean to the top of international political agendas. Predicting future conditions of the Arctic Ocean system requires scientific knowledge of its present status as well as a process-based understanding of the mechanisms of change. The Arctic in Rapid Transition (ART) initiative is an integrative, international, interdisciplinary pan-Arctic program to study changes and feedbacks among the physical and biogeochemical components of the Arctic Ocean and their ultimate impacts on biological productivity. The goal of ART is to develop priorities for Arctic marine science over the next decade. Three overarching questions form the basis of the ART science plan:
(1) How were past transitions in sea ice connected to energy flows, elemental cycling, biological diversity and productivity, and how do these compare to present and
projected shifts?
(2) How will biogeochemical cycling respond to transitions in terrestrial, gateway and shelf-to-basin fluxes?
(3) How do Arctic Ocean organisms and ecosystems respond to environmental transitions including temperature, stratification, ice conditions, and pH?
The integrated approach developed to answer the ART key scientific questions comprises: (a) process studies and observations to reveal mechanisms, (b) the establishment of links to existing monitoring programs, (c) the evaluation of geological records to extend time-series, and (d) the improvement of our modeling capabilities of climate-induced transitions. In order to develop an implementation plan for the ART initiative, an international and interdisciplinary workshop is currently planned to take place in Winnipeg, Canada in October 2010
Sampling planktonic salmon lice in Norwegian fjords
Risk of mortality of wild salmon caused by salmon lice is used as an index for managing aquaculture production in Norway and is based on monitoring of lice attached to wild salmonids and modelled concentrations of lice larvae in fjords. Direct sampling of lice from Norwegian waters to determine concentrations has never been published scientifically and has been considered non-feasible for monitoring purposes. Here we tested 4 different methods for sampling planktonic salmon lice copepodids. Salmon lice were found using all 4 methods with highly variable concentrations related to volume of filtered water with the different methods and patchy and variable distribution of lice within the fjords. Comparison between modelled and sampled lice concentrations showed variability within the same range and aspects of patchiness, and that the modelled concentrations were mostly lower than observed. We conclude that planktonic salmon lice can be sampled in Norwegian fjords with standard zooplankton sampling methods. Development of monitoring programmes of planktonic lice is possible but will demand a large amount of resources if implemented along the entire coast, because extensive sampling programmes and manpower for analysing samples are required to be able to capture the high spatiotemporal variability and patchy distribution of salmon lice. This calls for further development and use of modelling as a primary tool for national monitoring and management purposes. For further investigations of the effects of infestation pressure on wild salmonids, sampling combined with numerical modelling can provide valuable information.publishedVersio
Nutrients vs. turbulence, and the future of Arctic Ocean primary production
Poster no. B7 from Forum for Arctic Modeling & Observational Synthesis (Woods Hole Oceanographic Institution, 2-4 November
2016.This poster presents estimates of
nitrate fluxes in the Arctic Ocean and speculates on
the associated primary production in a future
climate
Hydrography, inorganic nutrients and chlorophyll a linked to sea ice cover in the Atlantic Water inflow region north of Svalbard
Changes in the inflow of Atlantic Water (AW) and its properties to the Arctic Ocean bring more warm water,
contribute to sea ice decline, promote borealisation of marine ecosystems, and affect biological and particularly
primary productivity in the Eurasian Arctic Ocean. One of the two branches of AW inflow follows the shelf
break north of Svalbard, where it dominates oceanographic conditions, bringing in heat, salt, nutrients and
organisms. However, the interplay with sea ice and Polar Surface Water (PSW) determines the supply of
nutrients to the euphotic layer especially northeast of Svalbard where AW subducts below PSW. In an effort to
build up a time series monitoring the key characteristics of the AW inflow, repeat sampling of hydrography,
macronutrients (nitrate, phosphate and silicate), and chlorophyll a (chl a) was undertaken along a transect
across the AW inflow at 31◦E, 81.5◦N since 2012 — first during late summer and in later years during early
winter. Such time series are scarce but invaluable for investigating the range of variability in hydrography and
nutrient concentrations. We investigate linkages between late summer hydrographic conditions and nutrient
concentrations along the transect and the preceding seasonal dynamics of surface chl a and sea ice cover in the
region north of Svalbard. We find large interannual variability in hydrography, nutrients and chl a, indicating
varying levels of nutrient drawdown by primary producers over summer. Sea ice conditions varied considerably
between the years, impacting upper ocean stratification, light availability and potential wind-driven mixing,
with a strong potential for steering chl a concentration over the productive season. Early winter measurements
show variable efficiency of nutrient re-supply through vertical mixing when stratification was low, related
to autumn wind forcing and sea ice conditions. While this re-supply elevates nutrient levels sufficiently for
primary production, it likely happens too late in the season when light levels are already low, limiting the
potential for autumn blooms. Such multidisciplinary observations provide insight into the interplay between
physical, chemical and biological drivers in the marine environment and are key to understanding ongoing
and future changes, especially at this entrance to the central Arctic Ocean
Seasonal variation in transport of zooplankton into the Arctic Basin through the Atlantic gateway, Fram Strait
Source at: http://doi.org/10.3389/fmars.2018.00194 The largest contribution of oceanic heat to the Arctic Ocean is the warm Atlantic Water (AW) inflow through the deep Fram Strait. The AW current also carries Atlantic plankton into the Arctic Basin and this inflow of zooplankton biomass through the Atlantic-Arctic gateway far exceeds the inflow through the shallow Pacific-Arctic gateway. However, because this transport has not yet been adequately quantified based on observational data, the present contribution is poorly defined, and future changes in Arctic zooplankton communities are difficult to project and observe. Our objective was to quantify the inflow of zooplankton biomass through the Fram Strait during different seasons, including winter. We collected data with high spatial resolution covering hydrography (CTD),currents (ADCP and LADCP) and zooplankton distributions (LOPC and MultiNet) from surface to 1,000 m depth along two transects crossing the AW inflow during three cruises in January, May and August 2014. Long-term variations (1997–2016) in the AW inflow were analyzed based on moored current meters. Water transport across the inflow
region was of the same order of magnitude during all months (January 2.2 Sv, May 1.9 Sv, August 1.7 Sv). We found a higher variability in zooplankton transport between
the months (January 51 kg C s −1 , May 34 kg C s −1 , August 50 kg C s −1), related to seasonal changes in the vertical distribution of zooplankton. However, high abundances
of carbon-rich copepods were observed in the AW inflow during all months. Surface patches with high abundances of C. finmarchicus, Microcalanus spp., Pseudocalanus
spp., and Oithona similis clearly contributed to the advected biomass, also in winter. The data reveal that the phenology of species is important for the amount of advected
biomass, and that the advective input of zooplankton carbon into the Arctic Basin is important during all seasons. The advective zooplankton input might be especially important for mesopelagic planktivorous predators that were recently observed in the region, particularly during winter. The inflow of C. finmarchicus with AW was estimated to
be in the order of 500,000 metric tons C y −1 , which compares well to modeled estimates
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