STUDI DESKRIPTIF LEVEL BERPIKIR GEOMETRI VAN HIELE SISWA DI SMP NEGERI PERCONTOHAN DI LEMBANG

Geometri sekolah mempunyai peluang besar untuk dipahami oleh siswa dibandingkan dengan cabang ilmu matematika yang lainnya. Hal ini dikarenakan pengenalan konsep dasar geometri sudah dikenal oleh siswa sejak usia dini, seperti mengenal bangun-bangun geometri. Namun beberapa penelitian menunjukkan bahwa masih banyak siswa yang mengalami kesulitan dalam belajar geeometri, khususnya pada tingkat SMP. Oleh karena itu diperlukan penelitian terhadap level berpikir geometri siswa. Penelitian ini bertujuan untuk mengetahui: (1) level berpikir geometri siswa di SMP Negeri percontohan di Lembang, dan (2) menelaah apakah pembelajaran geometri yang berlangsung di sekolah menerapkan tahapan pembelajaran Van Hiele atau tidak. Metode dalam penelitian ini merupakan studi deskriptif dengan subjek penelitian adalah siswa kelas IX dari dua sekolah menengah pertama di Lembang. Instrumen dalam penelitian ini terdiri dari: (1) instrumen tes, yaitu tes level berpikir geometri Van Hiele pada materi bangun datar. Hasil dari tes ini dianalisis dengan kategori level berpikir sebagai berikut: level 0 adalah tahap pengenalan; level 1 adalah tahap analisis; level 2 adalah tahap pengurutan; level 3 adalah tahap deduksi formal; dan level 4 adalah tahap akurasi. (2) Instrumen non tes, yaitu berupa wawancara terhadap guru dan murid. Berdasarkan hasil penelitian diperoleh kesimpulan bahwa: (1) secara keseluruhan siswa SMP telah memasuki tahap berpikir geometri Van Hiele. Sebagian besar siswa berada pada tahap pengenalan (level 0) yaitu 81,16%, sedangkan sisanya telah memasuki tahap analisis (level 1) sebesar 17,39% dan tahap pengurutan (level 2) sebesar 1,45%. (2) Pembelajaran geometri di sekolah kurang memperhatikan tahapan pembelajaran geometri Van Hiele---------- Student has a big opportunity to understand geometry because the basic concept has early familiar, such as know the geometry’s objects. However, some of the research were show that many student difficult to learn geometry, specifically for junior high school. Because of that, it necessary to research about the geometry level thinking. The goal of the research are to know: (1) student geometry level thinking at the model of junior high school in Lembang, and (2) observe the lesson geometry at school by use the phase of Van Hiele geometry learning. The method is descriptive study with the subject are the student from IX class of two junior high school in Lembang. The instrument is: (1) test instrument, is Van Hiele geometry level test. The result will be analysis by categories of Van Hiele: level 0 is visualization; level 1 is analysis; level 2 is informal deduction; level 3 is deduction; and level 4 is rigor. (2) Non-test instrument, is interview to the teacher and student. Base of the research, the conclusion are: (1) by and large the student has include the Van Hiele geometry level. Student at level 0 is 81, 16%, at level 1 is 17,3% and at level 2 is 1,45%. (2) School did’nt use the phase of Van Hiele geometry learning

A paradox of syntactic priming: why response tendencies show priming for passives, and response latencies show priming for actives

Speakers tend to repeat syntactic structures across sentences, a phenomenon called syntactic priming. Although it has been suggested that repeating syntactic structures should result in speeded responses, previous research has focused on effects in response tendencies. We investigated syntactic priming effects simultaneously in response tendencies and response latencies for active and passive transitive sentences in a picture description task. In Experiment 1, there were priming effects in response tendencies for passives and in response latencies for actives. However, when participants' pre-existing preference for actives was altered in Experiment 2, syntactic priming occurred for both actives and passives in response tendencies as well as in response latencies. This is the first investigation of the effects of structure frequency on both response tendencies and latencies in syntactic priming. We discuss the implications of these data for current theories of syntactic processing

A comparison of probe-level and probeset models for small-sample gene expression data

<p>Abstract</p> <p>Background</p> <p>Statistical methods to tentatively identify differentially expressed genes in microarray studies typically assume larger sample sizes than are practical or even possible in some settings.</p> <p>Results</p> <p>The performance of several probe-level and probeset models was assessed graphically and numerically using three spike-in datasets. Based on the Affymetrix GeneChip, a novel nested factorial model was developed and found to perform competitively on small-sample spike-in experiments.</p> <p>Conclusions</p> <p>Statistical methods with test statistics related to the estimated log fold change tend to be more consistent in their performance on small-sample gene expression data. For such small-sample experiments, the nested factorial model can be a useful statistical tool. This method is implemented in freely-available R code (affyNFM), available with a tutorial document at <url>http://www.stat.usu.edu/~jrstevens</url>.</p

The genomes of two key bumblebee species with primitive eusocial organization

Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

COST292 experimental framework for TRECVID 2008

In this paper, we give an overview of the four tasks submitted to TRECVID 2008 by COST292. The high-level feature extraction framework comprises four systems. The first system transforms a set of low-level descriptors into the semantic space using Latent Semantic Analysis and utilises neural networks for feature detection. The second system uses a multi-modal classifier based on SVMs and several descriptors. The third system uses three image classifiers based on ant colony optimisation, particle swarm optimisation and a multi-objective learning algorithm. The fourth system uses a Gaussian model for singing detection and a person detection algorithm. The search task is based on an interactive retrieval application combining retrieval functionalities in various modalities with a user interface supporting automatic and interactive search over all queries submitted. The rushes task submission is based on a spectral clustering approach for removing similar scenes based on eigenvalues of frame similarity matrix and and a redundancy removal strategy which depends on semantic features extraction such as camera motion and faces. Finally, the submission to the copy detection task is conducted by two different systems. The first system consists of a video module and an audio module. The second system is based on mid-level features that are related to the temporal structure of videos

Impact of the California Lead Ammunition Ban on Reducing Lead Exposure in Golden Eagles and Turkey Vultures

Predatory and scavenging birds may be exposed to high levels of lead when they ingest shot or bullet fragments embedded in the tissues of animals injured or killed with lead ammunition. Lead poisoning was a contributing factor in the decline of the endangered California condor population in the 1980s, and remains one of the primary factors threatening species recovery. In response to this threat, a ban on the use of lead ammunition for most hunting activities in the range of the condor in California was implemented in 2008. Monitoring of lead exposure in predatory and scavenging birds is essential for assessing the effectiveness of the lead ammunition ban in reducing lead exposure in these species. In this study, we assessed the effectiveness of the regulation in decreasing blood lead concentration in two avian sentinels, golden eagles and turkey vultures, within the condor range in California. We compared blood lead concentration in golden eagles and turkey vultures prior to the lead ammunition ban and one year following implementation of the ban. Lead exposure in both golden eagles and turkey vultures declined significantly post-ban. Our findings provide evidence that hunter compliance with lead ammunition regulations was sufficient to reduce lead exposure in predatory and scavenging birds at our study sites

Effect of yeast culture on milk production and metabolic and reproductive performance of early lactation dairy cows

<p>Abstract</p> <p>Background</p> <p>The main objective of this study was to estimate the effect of supplementation with <it>Saccaromyces cerevisiae (SC</it>) (Yea-Sacc^®1026) on milk production, metabolic parameters and the resumption of ovarian activity in early lactation dairy cows.</p> <p>Methods</p> <p>The experiment was conducted during 2005/2006 in a commercial tied-house farm with an average of 200 milking Estonian Holstein Friesian cows. The late pregnant multiparous cows (n = 46) were randomly divided into two groups; one group received 10 g yeast culture from two weeks before to 14 weeks after calving. The groups were fed a total mixed ration with silages and concentrates. Milk recording data and blood samples for plasma metabolites were taken. Resumption of luteal activity was determined using milk progesterone (P₄) measurements. Uterine bacteriology and ovarian ultrasonography (US) were performed and body condition scores (BCS) and clinical disease occurrences were recorded. For analysis, the statistical software Stata 9.2 and R were used to compute Cox proportional hazard and linear mixed models.</p> <p>Results</p> <p>The average milk production per cow did not differ between the groups (32.7 ± 6.4 vs 30.7 ± 5.3 kg/day in the SC and control groups respectively), but the production of milk fat (<it>P </it>< 0.001) and milk protein (<it>P </it>< 0.001) were higher in the SC group. There was no effect of treatment on BCS. The analysis of energy-related metabolites in early lactation showed no significant differences between the groups. In both groups higher levels of β-hydroxybutyrate (BHB) appeared from days 14 to 28 after parturition and the concentration of non-esterfied fatty acid (NEFA) was higher from days 1–7 post partum (PP). According to US and P₄results, all cows in both groups ovulated during the experimental period. The resumption of ovarian activity (first ovulations) and time required for elimination of bacteria from the uterus did not differ between the groups.</p> <p>Conclusion</p> <p>Supplementation with SC had an effect on milk protein and fat production, but did not influence the milk yield. No effects on PP metabolic status, bacterial elimination from the uterus nor the resumption of ovarian activity were found.</p