ANALISIS PEMAHAMAN KONSEP MATEMATIKA SISWA DENGAN MODEL PEMBELAJARAN PROBLEM BASED LEARNING PADA POKOK BAHASAN SEGITIGA (Study deskriptif di Kelas VII SMP Negeri 2 Plered Kab. Cirebon)

Anggun Maya Sari. NIM 59451058. “Analisis Pemahaman Konsep Matematika Siswa dengan Model Pembelajaran Problem Based Learning pada Pokok Bahasan Segitiga”. (Studi Deskriptif di Kelas VII SMP Negeri 2 Plered). Pembelajaran yang efektif adalah pembelajaran yang menyediakan kesempatan kepada siswa untuk belajar mandiri, sehingga dalam prosesnya siswa dapat memperoleh pemahaman dan pengetahuan dengan lebih mendalam. Akan tetapi proses kegiatan pembelajaran matematika yang berlangsung disekolah, pada umumnya guru hanya sekedar penyampai informasi tanpa mempertimbangkan seberapa jauh pemahaman siswa terhadap konsep matematika dari pokok bahasan segitiga yang disampaikan. Tujuan penelitian ini adalah 1) mengetahui seberapa besar pemahaman konsep yang dimiliki peserta didik; 2) mengetahui factor pendukung dan penghambat peserta didik dalam memahami konsep yang diberikan; 3) mengetahui deskripsi aktivitas siswa dalam memahami konsep matematika melalui model pembelajaran Problem Based Learning; 4) mengetahui respon siswa setelah melaksanakan model pembelajaran Problem Based Learning; 5) mengetahui sejauhmana pemahaman konsep matematika siswa setelah mengikuti proses pembelajaran Problem Based Learning. Penerapan model pembelajaran Problem Based Learning (PBL) merupakan salah satu model pembelajaran yang dapat memberikan kondisi belajar aktif kepada siswa. Dengan diterapkannya pembelajaran matematika dengan model pembelajaran PBL, diharapkan dapat membantu siswa dalam memahami konsep matematika. Penelitian ini menggunakan pendekatan kualitatif dan kuantitatif dengan metode deskriptif. Pengumpulan data menggunakan lembar observasi, pedoman wawancara, angket dan tes. Informan dalam penelitian ini adalah kelas VII yang sudah dibentuk kelompok kelas, yaitu VII A, VII D dan VII F. dengan menggunakan proportionate stratified random sampling, maka dari masingmasing kelompok kelas didapat 18 siswa sebagai informan penelitian. Berdasarkan dari hasil wawancara tentang siswa dalam pemahaman konsep matematika, diperoleh siswa masih kurang dan masih perlu banyak bimbingan. Aktivitas siswa selama pembelajaran melalui model pembelajaran PBL diperoleh dari hasil lembar observasi dengan nilai rata-rata dari semua aspek sebesar 54,39% yang termasuk dalam kategori sedang. Berdasarkan angket respon siswa setelah dilaksanakan model pembelajaran PBL termasuk dalam kategori baik dengan nilai rata-rata 76,44%. Pemahaman konsep matematika siswa setelah mengikuti proses pembelajaran dengan model pembelajaran PBL diperoleh siswa lebih rajin dalam mencari bahan untuk menyelesaikan soal-soal yang diberikan dan menambah pemahaman siswa mengenai konsep matematika, meski masih belum 100% benar, dan hasil tes didapat nilai rata-rata 39% yang termasuk dalam kategori sangat kurang. Kata Kunci: Pemahaman konsep matematika, Problem Based Learning, Segitig

Biotic homogenisation and differentiation as directional change in beta diversity: synthesising driver–response relationships to develop conceptualmodels across ecosystems

Biotic homogenisation is defined as decreasing dissimilarity among ecological assemblages sampled within a given spatial area over time. Biotic differentiation, in turn, is defined as increasing dissimilarity over time. Overall, changes in the spatial dissimilarities among assemblages (termed ‘beta diversity’) is an increasingly recognised feature of broader biodiversity change in the Anthropocene. Empirical evidence of biotic homogenisation and biotic differentiation remains scattered across different ecosystems. Most meta-analyses quantify the prevalence and direction of change in beta diversity, rather than attempting to identify underlying ecological drivers of such changes. By conceptualising the mechanisms that contribute to decreasing or increasing dissimilarity in the composition of ecological assemblages across space, environmental managers and conservation practitioners can make informed decisions about what interventions may be required to sustain biodiversity and can predict potential biodiversity outcomes of future disturbances. We systematically reviewed and synthesised published empirical evidence for ecological drivers of biotic homogenisation and differentiation across terrestrial, marine, and freshwater realms to derive conceptual models that explain changes in spatial beta diversity. We pursued five key themes in our review: (i) temporal environmental change; (ii) disturbance regime; (iii) connectivity alteration and species redistribution; (iv) habitat change; and (v) biotic and trophic interactions. Our first conceptual model highlights how biotic homogenisation and differentiation can occur as a function of changes in local (alpha) diversity or regional (gamma) diversity, independently of species invasions and losses due to changes in species occurrence among assemblages. Second, the direction and magnitude of change in beta diversity depends on the interaction between spatial variation (patchiness) and temporal variation (synchronicity) of disturbance events. Third, in the context of connectivity and species redistribution, divergent beta diversity outcomes occur as different species have different dispersal characteristics, and the magnitude of beta diversity change associated with species invasions also depends strongly on alpha and gamma diversity prior to species invasion. Fourth, beta diversity is positively linked with spatial environmental variability, such that biotic homogenisation and differentiation occur when environmental heterogeneity decreases or increases, respectively. Fifth, species interactions can influence beta diversity via habitat modification, disease, consumption (trophic dynamics), competition, and by altering ecosystem productivity. Our synthesis highlights the multitude of mechanisms that cause assemblages to be more or less spatially similar in composition (taxonomically, functionally, phylogenetically) through time. We consider that future studies should aim to enhance our collective understanding of ecological systems by clarifying the underlying mechanisms driving homogenisation or differentiation, rather than focusing only on reporting the prevalence and direction of change in beta diversity, per se. biodiversity, beta diversity, biotic homogenisation, biotic differentiation, species assemblage, turnoverpublishedVersio

Loss of health certificates among offshore petroleum workers on the Norwegian Continental Shelf 2002–2010

Background. A health certificate is required to work on the offshore petroleum installations of the Norwegian Shelf. Loss of health certificate (loss of licence, LOL) may cause economic problems for the individual worker. A private compensation system (OSO) was established for Norwegian offshore workers in 2002, comprising 8000–11,000 individual members of workers organisations: approximately one third of the population offshore. This study aims at describing the reasons for compensation of offshore workers who have lost their certificates. Materials and methods. Of 595 workers who applied for compensation in the period 2002–2010, 38 declined to participate in the study. Of the remaining 557, 507 were granted and 50 were denied compensation. All medical records held by the scheme concerning the 507 compensated applicants were examined. Health data were systematically extracted, analysed, and compared with general population statistics. Results. Musculoskeletal conditions were the most frequent conditions causing LOL for both sexes (42.5%), followed by psychiatric, neurological, and malignant diseases for women, and cardiovascular (19%), neurological, and psychiatric conditions for men. Musculoskeletal disorders were more prevalent than in the general population, and the prevalence of knee problems was particularly high. Among malignant diseases we found a high proportion of brain tumours and renal cancer. The causes are unknown and warrant further investigation in this population. Among women granted compensation, 78% were catering workers, while 50% of the men were process workers, reflecting the gender distribution in these working groups. Conclusions. Musculoskeletal conditions were the most frequent cause of application for LOL compensation for both sexes, followed by psychiatric, neurological, and malignant diseases for women, and cardiovascular, neurological, and psychiatric conditions for men. The cause of the higher incidence of musculoskeletal diseases, brain tumours, and renal cancer found in this study compared to the general population warrants further investigation

Long-term changes in taxonomic and functional composition of European marine fish communities

Evidence of large-scale biodiversity degradation in marine ecosystems has been reported worldwide, yet most research has focused on few species of interest or on limited spatiotemporal scales. Here we assessed the spatial and temporal changes in the taxonomic and functional composition of fish communities in European seas over the last 25 years (1994–2019). We then explored how these community changes were linked to environmental gradients and fishing pressure. We show that the spatial variation in fish species composition is more than two times higher than the temporal variation, with a marked spatial continuum in taxonomic composition and a more homogenous pattern in functional composition. The regions warming the fastest are experiencing an increasing dominance and total abundance of r-strategy fish species (lower age of maturity). Conversely, regions warming more slowly show an increasing dominance and total abundance of K-strategy species (high trophic level and late reproduction). Among the considered environmental variables, sea surface temperature, surface salinity and chlorophyll-a most consistently influenced communities' spatial patterns, while bottom temperature and oxygen had the most consistent influence on temporal patterns. Changes in communities' functional composition were more closely related to environmental conditions than taxonomic changes. Our study demonstrates the importance of integrating community-level species traits across multi-decadal scales and across a large region to better capture and understand ecosystem-wide responses and provides a different lens on community dynamics that could be used to support sustainable fisheries management.publishedVersio

Vurdering av MAREANOs opplegg for grabbprøvetaking av sedimentfauna - Harmonisering med prøvetaking etter Norsk Standard

Rapporten vurderer hvorvidt grabbundersøkelser av bunnfauna på MAREANO-lokaliteter i en fremtidig overvåking bør utføres ved bruk av standard for offshoreovervåkingen (5 prøver á 0,1 m2), eller om nåværende opplegg (2 prøver á 0,25 m2) kan beholdes. På grunt vann bør MAREANO benytte Norsk standard på stasjonene som blir med i et overvåkingsnettverk. På stasjoner kun for kartlegging kan nåværende strategi om ønskelig beholdes. Typiske 0,1 m2 grabber ansees ikke egnet på større dyp. Det er et behov for en bred diskusjon om hvordan sedimentfauna-overvåking skal foregå på dypt vann: design, redskap, antall paralleller, siktestørrelse og hvilke dyregrupper som skal inngå. Diskusjonen bør tas i en ekspert-workshop. Det anbefales å skille metodisk mellom overvåking på grunt og dypt vann. Færre paralleller på dype stasjoner kan føre til at man oppdager tidsendringer senere enn i grunne områder. Metodeforskjell kan vanskeliggjøre sammenligning mellom grunne og dype områder fordi det kan være vanskelig å skille faunaforskjeller som skyldes miljøfaktorer fra de som skyldes metodikk. Siden det er et klart skille i fauna på 600-800 m dyp utenfor sokkelen, bør grensen for bruk av lettere grabb i overvåkingen settes grunnere, f.eks. på 500 m

Depth-related gradients in community structure and relatedness of bivalves and isopods in the Southern Ocean

Despite increased research over the last decade, diversity patterns in Antarctic deep-sea benthic taxa and their driving forces are only marginally known. Depth-related patterns of diversity and distribution of isopods and bivalves collected in the Atlantic sector of the Southern Ocean are analysed. The data, sampled by epibenthic sledge at 40 deep-sea stations from the upper continental slope to the hadal zone (774–6348 m) over a wide area of the Southern Ocean, comprises 619 species of isopods and 81 species of bivalves. There were more species of isopods than bivalves in all samples, and species per station varied from 2 to 85 for isopods and from 0 to 18 for bivalves. Most species were rare, with 72% of isopod species restricted to one or two stations, and 45% of bivalves. Among less-rare species bivalves tended to have wider distributions than isopods. The species richness of isopods varied with depth, showing a weak unimodal curve with a peak at 2000–4000 m, while the richness of bivalves did not. Multivariate analyses indicate that there are two main assemblages in the Southern Ocean, one shallow and one deep. These overlap over a large depth-range (2000–4000 m). Comparing analyses based on the Sørensen resemblance measure and Γ+ (incorporating relatedness among species) indicates that rare species tend to have other closely related species within the same depth band. Analysis of relatedness among species indicates that the taxonomic variety of bivalves tends to decline at depth, whereas that of isopods is maintained. This, it is speculated, may indicate that the available energy at depth is insufficient to maintain a range of bivalve life-history strategies

Assessing sea floor functional biodiversity and vulnerability

The marine benthos has been largely studied through the use of response traits that characterise species vulnerability to disturbance. More limited has been the specific use of effect traits that represent other species descriptors and that express ecosystem functions. On the sea floor, the benthos is a key ecosystem-engineering component for which functions can be relevantly derived from effect traits. This study provides a typology of sea floor functions based on anextensive data compilation of effect traits. We classified 812 benthic invertebrate species from the northeast Atlantic by 15 effect traits expressing substratum alteration and habitat creation. Cluster analysis identified 15 species groups that represented various epi- or endobenthic functions. Beyond function−habitat specificity, we show that soft sediment species exhibited broader functionalniches in the trait space that increase multi-functionality, and were endowed with rare combinations of traits that expanded the functional extent of the species assemblage. As a consequence, soft sediments can host a higher functional diversity than hard substrata because a wider range of above- and below-substratum activities are possible in soft bottoms. Based on responsetraits documented for the same species and used to express vulnerability to natural or humaninduced disturbance, we then show that vulnerability within sea floor functions can be considerably variable. This can be a consequence of the independence between the evolutionary nature of response traits and the contingent engineering abilities of benthic species through effect traits. The paper provides theoretical and utilitarian clarifications on this trait dichotomy

Long-term environmental monitoring for assessment of change: measurement inconsistencies over time and potential solutions

The importance of long-term environmental monitoring and research for detecting and understanding changes in ecosystems and human impacts on natural systems is widely acknowledged. Over the last decades, a number of critical components for successful long-term monitoring have been identified. One basic component is quality assurance/quality control protocols to ensure consistency and comparability of data. In Norway, the authorities require environmental monitoring of the impacts of the offshore petroleum industry on the Norwegian continental shelf, and in 1996, a large-scale regional environmental monitoring program was established. As a case study, we used a sub-set of data from this monitoring to explore concepts regarding best practices for long-term environmental monitoring. Specifically, we examined data from physical and chemical sediment samples and benthic macroinvertebrate assemblages from 11 stations from six sampling occasions during the period 1996–2011. Despite the established quality assessment and quality control protocols for this monitoring program, we identified several data challenges, such as missing values and outliers, discrepancies in variable and station names, changes in procedures without calibration, and different taxonomic resolution. Furthermore, we show that the use of different laboratories over time makes it difficult to draw conclusions with regard to some of the observed changes. We offer recommendations to facilitate comparison of data over time. We also present a new procedure to handle different taxonomic resolution, so valuable historical data is not discarded. These topics have a broader relevance and application than for our case study

Biotic homogenisation and differentiation as directional change in beta diversity: synthesising driver–response relationships to develop conceptualmodels across ecosystems

Biotic homogenisation is defined as decreasing dissimilarity among ecological assemblages sampled within a given spatial area over time. Biotic differentiation, in turn, is defined as increasing dissimilarity over time. Overall, changes in the spatial dissimilarities among assemblages (termed 'beta diversity') is an increasingly recognised feature of broader biodiversity change in the Anthropocene. Empirical evidence of biotic homogenisation and biotic differentiation remains scattered across different ecosystems. Most meta-analyses quantify the prevalence and direction of change in beta diversity, rather than attempting to identify underlying ecological drivers of such changes. By conceptualising the mechanisms that contribute to decreasing or increasing dissimilarity in the composition of ecological assemblages across space, environmental managers and conservation practitioners can make informed decisions about what interventions may be required to sustain biodiversity and can predict potential biodiversity outcomes of future disturbances. We systematically reviewed and synthesised published empirical evidence for ecological drivers of biotic homogenisation and differentiation across terrestrial, marine, and freshwater realms to derive conceptual models that explain changes in spatial beta diversity. We pursued five key themes in our review: (i) temporal environmental change" (ii) disturbance regime" (iii) connectivity alteration and species redistribution" (iv) habitat change" and (v) biotic and trophic interactions. Our first conceptual model highlights how biotic homogenisation and differentiation can occur as a function of changes in local (alpha) diversity or regional (gamma) diversity, independently of species invasions and losses due to changes in species occurrence among assemblages. Second, the direction and magnitude of change in beta diversity depends on the interaction between spatial variation (patchiness) and temporal variation (synchronicity) of disturbance events. Third, in the context of connectivity and species redistribution, divergent beta diversity outcomes occur as different species have different dispersal characteristics, and the magnitude of beta diversity change associated with species invasions also depends strongly on alpha and gamma diversity prior to species invasion. Fourth, beta diversity is positively linked with spatial environmental variability, such that biotic homogenisation and differentiation occur when environmental heterogeneity decreases or increases, respectively. Fifth, species interactions can influence beta diversity via habitat modification, disease, consumption (trophic dynamics), competition, and by altering ecosystem productivity. Our synthesis highlights the multitude of mechanisms that cause assemblages to be more or less spatially similar in composition (taxonomically, functionally, phylogenetically) through time. We consider that future studies should aim to enhance our collective understanding of ecological systems by clarifying the underlying mechanisms driving homogenisation or differentiation, rather than focusing only on reporting the prevalence and direction of change in beta diversity, per se