PENGARUH PENDEKATAN REALISTIC MATHEMATICS EDUCATION TERHADAP KEMAMPUAN BERPIKIR KRITIS DAN KEMAMPUAN PEMECAHAN MASALAH MATEMATIS SEKOLAH DASAR

Kemampuan berpikir kritis dan kemampuan pemecahan masalah matematis merupakan kemampuan yang sangat penting yang harus dimiliki siswa Sekolah Dasar. Hal ini akan membantu dalam mengembangkan potensi dirinya, dengan menitikberatkan pada kemampuan dalam berpikir dan bertindak secara normatif, dan siap bernalar dari apa yang dilihat maupun didengar sehingga dapat menyelesaikan permasalahan yang dihadapinya dalam kehidupan sehari-hari, oleh karena itu peranan guru sebagai tenaga pendidik secara professional menjadi penentu dalam menjembatani siswa melalui pembelajaran yang berkualitas. Namun kenyataannya berkaitan dengan proses pembelajaran matematika di SD proses pembelajaran yang dilaksanakan belum memberikan kesempatan siswa dalam menggali potensi dirinya dalam berpikir kritis dan menyelesaikan permasalahan. Sehingga perlu dicari alternatif pembelajaran yang dapat meningkatkan kemampuan berpikir kritis dan kemampuan pemecahan masalah. Pendekatan Realistic Mathematics Education merupakan salah satu alternatif yang digunakan untuk meningkatkan kemampuan berpikir kritis dan kemampuan pemecahan masalah matematis. Penelitian ini bertujuan untuk mengetahui apakah pendekatan Realistic Mathematics Education dapat meningkatkan kemampuan berpikir kritis dan kemampuan pemecahan masalah matematis dalam pembelajaran matematika di Sekolah Dasar. Penelitian ini dilaksanakan menggunakan metode kuasi eksperimen dengan desain kelompok kontrol non-Ekuivalen. Sampel dalam penelitian adalah siswa kelas IV pada salah satu SD di Kabupaten Garut. Pengumpulan data dilakukan dengan tes berbentuk uraian dan lembar observasi selama proses pembelajaran. Untuk pengolahan data digunakan program SPSS versi 20. Berdasarkan hasil penelitian berupa skor N-gain dianalisis dengan menggunakan uji t-tes. Hasil penelitian yang dianalisis menunjukkan bahwa terdapat peningkatan kemampuan berpikir kritis dan kemampuan pemecahan masalah matematis yang belajar melalui pendekatan Realistic Mathematics Education (RME) dengan yang menggunakan pembelajaran biasa. Jadi dapat disimpulkan peningkatan kemampuan berpikir kritis dan kemampuan pemecahan masalah matematis dengan menggunakan Realistic Mathematics Education (RME) lebih baik dari siswa yang mendapatkan pembelajaran biasa ---------- Critical thinking skills and mathematical problem solving ability is a very important capability that should be owned by elementary school students. These abilities would help students to improve their potential, with concern on the ability to think and act as normative, and ready to have a reason of what is seen and heard so that they can solve their problems in daily life, therefore the role of the teacher as professional educators be decisive in bridging the students through quality learning. But in the reality, relates to the process of learning mathematics in elementary school, learning process which implemented yet provide an opportunity for students to explore their potential in critical thinking to solve the problems. so it is necessary to find an alternative learning that can improve critical thinking skills and problem solving skills. Realistic Mathematics Education approach is one alternative that is used to improve critical thinking skills and mathematical problem-solving abilities. This research aims to determine whether Realistic Mathematics Education approach can improve the ability of critical thinking and mathematical problem solving ability in mathematics in elementary school. This research was conducted using a quasi-experimental design with a control group of non-Equivalent. Samples were fourth grade students in one elementary school in Garut. Data collected by the description and the sheet-shaped test observations during the learning process. For data processing used SPSS version 20. Based on the results of research in the form of N-gain scores were analyzed using t-test, which analyzed research results show that there are increasing in the ability of critical thinking and problem solving skills are learned through mathematical approach Realistic Mathematics Education (RME) with the use of regular learning. So we can conclude the increase in critical thinking skills and mathematical problem-solving abilities by using Realistic Mathematics Education (RME) is better than the students who get regular learnin

Domestication leads to increased predation susceptibilit

Domestication involves adapting animals to the human-controlled environment. Genetic changes occurring during the domestication process may manifest themselves in phenotypes that render domesticated animals maladaptive for life in the wild. Domesticated Atlantic salmon frequently interbreed with wild conspecifics, and their offspring display reduced survival in the wild. However, the mechanism(s) contributing to their lower survival in the wild remains a subject of conjecture. Here, we document higher susceptibility to predation by brown trout in fast-growing domesticated salmon, as compared to their slow-growing wild conspecifics, demonstrating that directional selection for increased growth comes at a cost of decreased survival when under the risk of predation, as predicted by the growth/predation risk trade-off. Despite earlier documentation of altered risk-taking behavior, this study demonstrates for the first time that domestication of Atlantic salmon has lead to increased predation susceptibility, and that this consitutes a mechanism underpinning the observed survial differences in the wild.publishedVersio

An Ecological-Economic Simulation Model of Genetic interaction Between Farmed and Wild Salmon

The paper is the first attempt to explore the ecological and economic impacts of genetic interaction between farmed and wild salmon over generations. An age- and stage-structured bioeconomic model is developed. The biological part of the model includes age-specific life history traits such as survival rate, fecundity, spawning success for both wild and farmed salmon and their hybrids, while the economic part takes account of market and non-market values of fish stock. The model is constructed based on the Atlantic salmon fishery and salmon farming in Norway. The discounted profits are estimated given the current fishing practice over 50 years. The sensitivity analysis is also performed. It is expected that wild salmon stock will be gradually replaced with hybrid ones, while the total discounted profit will decline, but not significantly. The analysis will provide some new insights for designing effective management strategies to protect wild salmon stocks from genetic intrusion of farmed escapees.Keywords: Fisheries Economics, Aquaculture, Aquaculture and EnvironmentKeywords: Fisheries Economics, Aquaculture, Aquaculture and Environmen

Smittebegrensende behandling med aluminiumssulfat (AIS) mot lakseparasitten Gyrodactylus salaris i Lærdalselva 2008.

Smittereduserende behandling mot lakseparasitten Gyrodactylus salaris med aluminiumsulfat (AlS) som hovedkjemikalium ble gjennomført i Lærdalselva i april 2008. CFT-legumin (rotenon) ble brukt i stillestående vann og mindre vannforekomster der det ikke var hensiktsmessig å bruke AlS. Denne rapporten omhandler kun AlS-behandlingen. Behandlingen startet 4. april og varte til 17.april. Det ble oppnådd en vannkjemi som er dokumentert å være tilstrekkelig for å fjerne infeksjon av G. salaris fra laks (pH 35 µg/l), og denne ble opprettholdt over en periode på 9-12 dager. Under behandlingen ble PI-styring av syredosering med pH som styringsparameter brukt, noe som ga jevn og kontrollert dosering av kjemikalier under hele behandlingsperioden. Fisk fra elva ble undersøkt daglig for infeksjon av G. salaris, og parasittinfeksjonen ble redusert fra 91 % til 0 % i løpet av 10 dager.Veterinærinstituttet, seksjon for miljø- og smittetilta

Spawning targets for Atlantic salmon in the River Näätämöjoki/Neidenelva

Salmon populations should be managed in a population-specific and target-based manner, and therefore biological reference points and consequent management targets should be established for each salmon population. In Norway, first-generation management targets in the form of spawning targets were established in 2007. In the case of the transboundary River Näätämöjoki/Neidenelva spawning targets were then set only for the Norwegian side of the river system. In this report we present the estimated spawning targets for the whole Näätämöjoki/Neidenelva system including the Finnish side. The spawning targets are presented separately for the Näätämöjoki/Neidenelva mainstem, for tributaries Silisjoki and Harrijoki and for the whole system. Spawning target of the Norwegian side was also updated by using more accurate habitat knowledge. The total spawning target of the River Näätämöjoki/Neidenelva system was estimated at slightly over 10 000 000 salmon eggs. This converts to 5634 kg of female salmon when using fecundity of 1800 eggs/female salmon kg and 4558 kg when using the fecundity level of 2225 eggs/female salmon kg. Based on the production area size and their value to salmon production 66% of the spawning target is situated in Finland and 34% in Norway. In practise depending on the chosen fecundity level, c. 650–800 female salmon averaging a weight of 4.65 kg are annually needed on the Finnish side and c. 330–410 females on the Norwegian side of the Näätämöjoki/Neidenelva to fulfil the spawning targets. Although the spawning targets are expressed in female salmon biomass and numbers, male salmon are also needed for successful spawning and recruitment

Large-effect loci mediate rapid adaptation of salmon body size after river regulation

Understanding the potential of natural populations to adapt to altered environments is becoming increasingly relevant in evolutionary research. Currently, our understanding of adaptation to human alteration of the environment is hampered by lack of knowledge on the genetic basis of traits, lack of time series, and little or no information on changes in optimal trait values. Here, we used time series data spanning nearly a century to investigate how the body mass of Atlantic salmon (Salmo salar) adapts to river regulation. We found that the change in body mass followed the change in waterflow, both decreasing to ∼1/3 of their original values. Allele frequency changes at two loci in the regions of vgll3 and six6 predicted more than 80% of the observed body mass reduction. Modeling the adaptive dynamics revealed that the population mean lagged behind its optimum before catching up approximately six salmon generations after the initial waterflow reduction. Our results demonstrate rapid adaptation mediated by large-effect loci and provide insight into the temporal dynamics of evolutionary rescue following human disturbance.publishedVersio

Genetic stock identification reveals greater use of an oceanic feeding ground around the Faroe Islands by multi-sea winter Atlantic salmon, with variation in use across reporting groups

While it is known that the oceans around the Faroe Islands support an Atlantic salmon (Salmo salar) feeding ground, the relative use of this resource by different age classes and populations remains largely unexplored. Using genetic stock identification and run-reconstruction modelling, we observed a consistent pattern whereby the proportion of multi-sea winter salmon (MSW-fish that have spent multiple winters at sea) for a reporting group was substantially greater around the Faroes than the MSW proportion among that group's corresponding pre-fisheries abundance. Surprisingly, MSW fish from Ireland and the United Kingdom were as likely to occur around the Faroes as were MSW fish from more north-eastern regions. While 1SW salmon (single sea-winter fish) from Ireland and the United Kingdom as well as Southern Norway occurred in similar proportions around the Faroes, 1SW fish from the north-eastern regions were virtually absent. Our results indicate that the oceans around the Faroes host a predominantly MSW feeding ground and use of this resource varies across age classes and reporting groups. Furthermore, these results suggest that MSW fish from some reporting groups preferentially migrate to the Faroes. Variation in spatial resource use may help buffer salmon populations against localized negative changes in marine conditions via portfolio effects.Peer reviewe

Can variation in standard metabolic rate explain context-dependent performance of farmed Atlantic salmon offspring?

Escaped farmed Atlantic salmon interbreed with wild Atlantic salmon, leaving offspring that often have lower success in nature than pure wild salmon. On top of this, presence of farmed salmon descendants can impair production of wild‐type recruits. We hypothesize that both these effects connect with farmed salmon having acquired higher standard metabolic rates (SMR, the energetic cost of self‐maintenance) during domestication. Fitness‐related advantages of phenotypic traits associated with both high SMR and farmed salmon (e.g., social dominance) depend on environmental conditions, such as food availability. We hypothesize that farmed offspring have an advantage at high food availability due to, for example, dominance behavior but suffer increased risks of starvation when food is scarce because this behavior is energy‐demanding. To test these hypotheses, we first compare embryo SMR of pure farmed, farmed‐wild hybrids and pure wild offspring. Next, we test early‐life performance (in terms of survival and growth) of hybrids relative to that of their wild half‐siblings, as well as their competitive abilities, in semi‐natural conditions of high and low food availability. Finally, we test how SMR affects early‐life performance at high and low food availability. We find inconclusive support for the hypothesis that domestication has induced increased SMR. Further, wild and hybrid juveniles had similar survival and growth in the semi‐natural streams. Yet, the presence of hybrids led to decreased survival of their wild half‐siblings. Contrary to our hypothesis about context‐dependency, these effects were not modified by food availability. However, wild juveniles with high SMR had decreased survival when food was scarce, but there was no such effect at high food availability. This study provides further proof that farmed salmon introgression may compromise the viability of wild salmon populations. We cannot, however, conclude that this is connected to alterations in the metabolic phenotype of farmed salmon

Thiamin dynamics during the adult life cycle of Atlantic salmon (Salmo salar)

Thiamin is an essential water-soluble B vitamin known for its wide range of metabolic functions and antioxidant properties. Over the past decades, reproductive failures induced by thiamin deficiency have been observed in several salmonid species worldwide, but it is unclear why this micronutrient deficiency arises. Few studies have compared thiamin concentrations in systems of salmonid populations with or without documented thiamin deficiency. Moreover, it is not well known whether and how thiamin concentration changes during the marine feeding phase and the spawning migration. Therefore, samples of Atlantic salmon (Salmo salar) were collected when actively feeding in the open Baltic Sea, after the sea migration to natal rivers, after river migration, and during the spawning period. To compare populations of Baltic salmon with systems without documented thiamin deficiency, a population of landlocked salmon located in Lake Vänern (Sweden) was sampled as well as salmon from Norwegian rivers draining into the North Atlantic Ocean. Results showed the highest mean thiamin concentrations in Lake Vänern salmon, followed by North Atlantic, and the lowest in Baltic populations. Therefore, salmon in the Baltic Sea seem to be consistently more constrained by thiamin than those in other systems. Condition factor and body length had little to no effect on thiamin concentrations in all systems, suggesting that there is no relation between the body condition of salmon and thiamin deficiency. In our large spatiotemporal comparison of salmon populations, thiamin concentrations declined toward spawning in all studied systems, suggesting that the reduction in thiamin concentration arises as a natural consequence of starvation rather than to be related to thiamin deficiency in the system. These results suggest that factors affecting accumulation during the marine feeding phase are key for understanding the thiamin deficiency in salmonids. Atlantic salmon, Baltic Sea, M74 syndrome, Salmon life cycle, Thiamin, Thiamin deficiencypublishedVersio

Iteroparity and its contribution to life-history variation in Atlantic salmon

Evolution of iteroparity is shaped by the trade-off between current and future reproduction.We studied variation in iteroparity among 205 050 individual Atlantic salmon caught in 179 rivers spanning 14◦ of latitude. The proportion of repeat spawners (iteroparous individuals) averaged 3.8% and ranged from 0% to 26% across rivers. Females were more often repeat spawners than males and had lower cost of reproduction in terms of lost body mass between spawning events. Proportion of repeat spawners for a given sea age at maturity, and the ratio of alternate to consecutive repeat spawners, increased with increasing population mean sea age at maturity. By combining smolt age, sea age at maturity, and age at additional spawning events, we identified 141 unique life-history types, and repeat spawners contributed 75% of that variation. Our results show that repeat spawners are important for life-history variation and suggest that the association between mean sea age and the frequency of repeat spawning is adaptive rather than a pleiotropic side effect arising from selection on sea age. age at maturity, life-history evolution, local adaptation, repeat spawning, trade-offpublishedVersio