bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative Characterization of Hypoeutectic Aluminum–Silicon–Copper As-Cast Alloy Microstructures
Authors: Kazakov A. , Kur A. , Kazakova E. , Kiselev D. 
Published: September 2016

Abstract
There are only two kinds of qualitative methods for the estimation of aluminum alloy structures: (1) bar charts (degree of eutectic fineness, porosity content, etc.), and (2) atlases of microstructures, mainly for rejection (overheating, for example). In this paper, the development of quantitative methods for the characterization of hypoeutectic Al-Si-Cu as-cast alloy microstructures using panoramic image analysis is described. As-cast and solution-annealed Al-6Si-2Cu alloy microstructures were studied. Parameters for monitoring the quality of the structure of this alloy were proposed. New algorithms for automatic estimation of eutectic fineness and its volume fraction were developed. Correlations among different microstructural parameters were found and interpreted using thermodynamic simulation. The grade of porosity according to GOST 1583-93 versus pore volume fraction, calculated by ASTM E1245, was defined. Bar charts for estimation of the average length of eutectic silicon particles were proposed. The eutectic modification grade, according to the American Foundry Society chart for microstructure control of hypoeutectic alloys, versus both the length and the elongation of eutectic silicon particles was determined. The relationships between alloy hardness and tensile elongation versus the proposed microstructural parameters for Al-6Si-2Cu alloy were defined. These relationships describe various grades of hypoeutectic Al-Si-Cu alloys in both the as-cast and as-solution-annealed conditions.
Transitional Probabilities Are Prioritized over Stimulus/Pattern Probabilities in Auditory Deviance Detection: Memory Basis for Predictive Sound Processing
Authors: Mittag Maria , Takegata Rika , Winkler István 
Published: September 2016

Representations encoding the probabilities of auditory events do not directly support predictive processing. In contrast, information about the probability with which a given sound follows another (transitional probability) allows predictions of upcoming sounds. We tested whether behavioral and cortical auditory deviance detection (the latter indexed by the mismatch negativity event-related potential) relies on probabilities of sound patterns or on transitional probabilities. We presented healthy adult volunteers with three types of rare tone-triplets among frequent standard triplets of high-low-high (H-L-H) or L-H-L pitch structure: proximity deviant (H-H-H/L-L-L), reversal deviant (L-H-L/H-L-H), and first-tone deviant (L-L-H/H-H-L). If deviance detection was based on pattern probability, reversal and first-tone deviants should be detected with similar latency because both differ from the standard at the first pattern position. If deviance detection was based on transitional probabilities, then reversal deviants should be the most difficult to detect because, unlike the other two deviants, they contain no low-probability pitch transitions. The data clearly showed that both behavioral and cortical auditory deviance detection uses transitional probabilities. Thus, the memory traces underlying cortical deviance detection may provide a link between stimulus probability-based change/novelty detectors operating at lower levels of the auditory system and higher auditory cognitive functions that involve predictive processing.SIGNIFICANCE STATEMENTOur research presents the first definite evidence for the auditory system prioritizing transitional probabilities over probabilities of individual sensory events. Forming representations for transitional probabilities paves the way for predictions of upcoming sounds. Several recent theories suggest that predictive processing provides the general basis of human perception, including important auditory functions, such as auditory scene analysis. Our results demonstrate that the memory traces underlying cortical deviance detection form a link between stimulus probability-based change/novelty detectors operating at lower levels of the auditory system and higher auditory cognitive functions that involve predictive processing.
Distinct fMRI Responses to Self-Induced versus Stimulus Motion during Free Viewing in the Macaque
Authors: Russ Brian E. , Kaneko Takaaki , Saleem Kadharbatcha S. , Berman Rebecca A. , Leopold David A. 
Published: September 2016

Visual motion responses in the brain are shaped by two distinct sources: the physical movement of objects in the environment and motion resulting from one's own actions. The latter source, termed visual reafference, stems from movements of the head and body, and in primates from the frequent saccadic eye movements that mark natural vision. To study the relative contribution of reafferent and stimulus motion during natural vision, we measured fMRI activity in the brains of two macaques as they freely viewed >50 hours of naturalistic video footage depicting dynamic social interactions. We used eye movements obtained during scanning to estimate the level of reafferent retinal motion at each moment in time. We also estimated the net stimulus motion by analyzing the video content during the same time periods. Mapping the responses to these distinct sources of retinal motion, we found a striking dissociation in the distribution of visual responses throughout the brain. Reafferent motion drove fMRI activity in the early retinotopic areas V1, V2, V3, and V4, particularly in their central visual field representations, as well as lateral aspects of the caudal inferotemporal cortex (area TEO). However, stimulus motion dominated fMRI responses in the superior temporal sulcus, including areas MT, MST, and FST as well as more rostral areas. We discuss this pronounced separation of motion processing in the context of natural vision, saccadic suppression, and the brain's utilization of corollary discharge signals.SIGNIFICANCE STATEMENTVisual motion arises not only from events in the external world, but also from the movements of the observer. For example, even if objects are stationary in the world, the act of walking through a room or shifting one's eyes causes motion on the retina. This “reafferent” motion propagates into the brain as signals that must be interpreted in the context of real object motion. The delineation of whole-brain responses to stimulus versus self-generated retinal motion signals is critical for understanding visual perception and is of pragmatic importance given the increasing use of naturalistic viewing paradigms. The present study uses fMRI to demonstrate that the brain exhibits a fundamentally different pattern of responses to these two sources of retinal motion.
The Interglomerular Circuit Potently Inhibits Olfactory Bulb Output Neurons by Both Direct and Indirect Pathways
Authors: Liu Shaolin , Puche Adam C. , Shipley Michael T. 
Published: September 2016

Sensory processing shapes our perception. In mammals, odor information is encoded by combinatorial activity patterns of olfactory bulb (OB) glomeruli. Glomeruli are richly interconnected by short axon cells (SACs), which form the interglomerular circuit (IGC). It is unclear how the IGC impacts OB output to downstream neural circuits. We combinedin vitroandin vivoelectrophysiology with optogenetics in mice and found the following: (1) the IGC potently and monosynaptically inhibits the OB output neurons mitral/tufted cells (MTCs) by GABA release from SACs: (2) gap junction-mediated electrical coupling is strong for the SAC→MTC synapse, but negligible for the SAC→ETC synapse; (3) brief IGC-mediated inhibition is temporally prolonged by the intrinsic properties of MTCs; and (4) sniff frequency IGC activationin vivogenerates persistent MTC inhibition. These findings suggest that the temporal sequence of glomerular activation by sensory input determines which stimulus features are transmitted to downstream olfactory networks and those filtered by lateral inhibition.SIGNIFICANCE STATEMENTOdor identity is encoded by combinatorial patterns of activated glomeruli, the initial signal transformation site of the olfactory system. Lateral circuit processing among activated glomeruli modulates olfactory signal transformation before transmission to higher brain centers. Using a combination ofin vitroandin vivooptogenetics, this work demonstrates that interglomerular circuitry produces potent inhibition of olfactory bulb output neurons via direct chemical and electrical synapses as well as by indirect pathways. The direct inhibitory synaptic input engages mitral cell intrinsic membrane properties to generate inhibition that outlasts the initial synaptic action.
Soluble Conformers of Aβ and Tau Alter Selective Proteins Governing Axonal Transport
Authors: Sherman Mathew A. , LaCroix Michael , Amar Fatou , Larson Megan E. , Forster Colleen , Aguzzi Adriano , Bennett David A. , Ramsden Martin , Lesné Sylvain E. 
Published: September 2016

Despite the demonstration that amyloid-β (Aβ) can trigger increased tau phosphorylation and neurofibrillary tangle (NFT) formationin vivo, the molecular link associating Aβ and tau pathologies remains ill defined. Here, we observed that exposure of cultured primary neurons to Aβ trimers isolated from brain tissue of subjects with Alzheimer's disease led to a specific conformational change of tau detected by the antibody Alz50. A similar association was supported by postmortem human brain analyses. To study the role of Aβ trimersin vivo, we created a novel bigenic Tg-Aβ+Tau mouse line by crossing Tg2576 (Tg-Aβ) and rTg4510 (Tg-Tau) mice. Before neurodegeneration and amyloidosis, apparent Aβ trimers were increased by ∼2-fold in 3-month-old Tg-Aβ and Tg-Aβ+Tau mice compared with younger mice, whereas soluble monomeric Aβ levels were unchanged. Under these conditions, the expression of soluble Alz50-tau conformers rose by ∼2.2-fold in the forebrains of Tg-Aβ+Tau mice compared with nontransgenic littermates. In parallel, APP accumulated intracellularly, suggestive of a putative dysfunction of anterograde axonal transport. We found that the protein abundance of the kinesin-1 light chain (KLC1) was reduced selectivelyin vivoandin vitrowhen soluble Aβ trimers/Alz50-tau were present. Importantly, the reduction in KLC1 was prevented by the intraneuronal delivery of Alz50 antibodies. Collectively, our findings reveal that specific soluble conformers of Aβ and tau cooperatively disrupt axonal transport independently from plaques and tangles. Finally, these results suggest that not all endogenous Aβ oligomers trigger the same deleterious changes and that the role of each assembly should be considered separately.SIGNIFICANCE STATEMENTThe mechanistic link between amyloid-β (Aβ) and tau, the two major proteins composing the neuropathological lesions detected in brain tissue of Alzheimer's disease subjects, remains unclear. Here, we report that the trimeric Aβ species induce a pathological modification of tau in cultured neurons and in bigenic mice expressing Aβ and human tau. This linkage was also observed in postmortem brain tissue from subjects with mild cognitive impairment, when Aβ trimers are abundant. Further, this modification of tau was associated with the intracellular accumulation of the precursor protein of Aβ, APP, as a result of the selective decrease in kinesin light chain 1 expression. Our findings suggest that Aβ trimers might cause axonal transport deficits in AD.
Dopamine Manipulation Affects Response Vigor Independently of Opportunity Cost
Authors: Zénon Alexandre , Devesse Sophie , Olivier Etienne 
Published: September 2016

Dopamine is known to be involved in regulating effort investment in relation to reward, and the disruption of this mechanism is thought to be central in some pathological situations such as Parkinson's disease, addiction, and depression. According to an influential model, dopamine plays this role by encoding the opportunity cost, i.e., the average value of forfeited actions, which is an important parameter to take into account when making decisions about which action to undertake and how fast to execute it. We tested this hypothesis by asking healthy human participants to perform two effort-based decision-making tasks, following either placebo or levodopa intake in a double blind within-subject protocol. In the effort-constrained task, there was a trade-off between the amount of force exerted and the time spent in executing the task, such that investing more effort decreased the opportunity cost. In the time-constrained task, the effort duration was constant, but exerting more force allowed the subject to earn more substantial reward instead of saving time. Contrary to the model predictions, we found that levodopa caused an increase in the force exerted only in the time-constrained task, in which there was no trade-off between effort and opportunity cost. In addition, a computational model showed that dopamine manipulation left the opportunity cost factor unaffected but altered the ratio between the effort cost and reinforcement value. These findings suggest that dopamine does not represent the opportunity cost but rather modulates how much effort a given reward is worth.SIGNIFICANCE STATEMENTDopamine has been proposed in a prevalent theory to signal the average reward rate, used to estimate the cost of investing time in an action, also referred to as opportunity cost. We contrasted the effect of dopamine manipulation in healthy participants in two tasks, in which increasing response vigor (i.e., the amount of effort invested in an action) allowed either to save time or to earn more reward. We found that levodopa—a synthetic precursor of dopamine—increases response vigor only in the latter situation, demonstrating that, rather than the opportunity cost, dopamine is involved in computing the expected value of effort.
Body Composition and BMI Growth Charts in Children With Down Syndrome
Authors: Hatch-Stein Jacquelyn A. , Zemel Babette S. , Prasad Divya , Kalkwarf Heidi J. , Pipan Mary , Magge Sheela N. , Kelly Andrea 
Published: September 2016

BACKGROUND AND OBJECTIVES:New US Down syndrome (DS) BMI growth charts were recently published, but their utility in identifying children with excess adiposity or increased cardiometabolic risk (CMR) remains unknown. We sought to compare the ability of the Centers for Disease Control and Prevention (CDC) BMI 85th percentile and DS-specific BMI 85th percentile to identify excess adiposity in children with DS.METHODS:Participants with DS aged 10 to 20 years were enrolled in a cross-sectional CMR study. Data from typically developing children enrolled in the Bone Mineral Density in Childhood Study (BMDCS) were used for comparison. Sensitivity and specificity were calculated to assess the CDC BMI 85th percentile in the BMDCS and DS groups, and the DS-specific BMI 85th percentile in the DS group, relative to fat mass index (FMI) ≥80th percentile, a threshold associated with increased CMR.RESULTS:Included were 121 DS participants (age 14.8 ± 3.3 years, 57% girls) and 7978 BMDCS reference data points (age 15.0 ± 3.0 years, 51.3% girls). The CDC BMI 85th percentile identified FMI ≥80th percentile with 96.9% sensitivity and 87.4% specificity in typically developing children. Similarly, the CDC BMI 85th percentile identified FMI ≥80th percentile with 100% sensitivity and 78.3% specificity in children with DS. In contrast, the sensitivity of the DS-specific BMI 85th percentile was only 62.3% (P &lt; .0001), but was 100% specific.CONCLUSIONS:For children with DS ≥10 years, the CDC BMI growth chart 85th percentile is a better indicator of excess adiposity, than the new DS-specific BMI charts. Additional studies are needed to clarify the relationships of BMI and FMI with CMR in DS.
PROSES BRAZING Cu-Ag BERBAHAN BAKAR BIOGAS TERMURNIKAN
Authors: Kusrijadi Ali , Triyono Budi , Riswanda Ms 
Published: September 2016

Pemanfaatan biogas sebagai salah satu alternatif bahan bakar pada proses brazing merupakan langkah diversifikasi biogas, yang diharapkan dapat meningkatkan tingkat efisiensi dan keramahan teknologi. Permasalahan yang bersifat teknis dan menjadi kendala dalam pemanfaatan biogas ini adalah rendahnya konsentrasi CH4 dikarenakan adanya pengotor utama berupa air, karbondioksida dan asam disulfida. Penelitian dilakukan melalui dua tahap yaitu tahap pressureized storage process meliputi pemisahan komponen pengotor yang terdapat dalam biogas melalui teknik absorbsi sehingga dihasilkan biogas yang berkualitas gas alam terbarukan dan proses injeksi ke dalam suatu tangki penyimpanan, dan tahap selanjutnya adalah menggunakan biogas tersebut pada proses brazing logam Cu (tembaga) dengan bahan tambah Ag (silver). Analisis hasil brazing dilakukan melalui analisis struktur mikro (metalografi) untuk melihat kualitas tampak dari hasil brazing, serta analisis kekerasan mikro dan analisis parameter fisik standar terhadap hasil proses brazing. Penelitian ini telah menghasilkan perangkat alat pemurnian biogas yang dapat memurnikan biogas menjadi metana mendekati 100% dan sistem pengemasan (storage system) biogas bertekanan hingga 2 bar. Dari hasil analisis struktur mikro dan uji kekerasan mikro diketahui bahwa hasil proses brazing dengan biogas menghasilkan kualitas yang sama dengan hasil proses brazing dengan gas acetylene sehingga disimpulkan bahwa biogas dapat menjadi bahan bakar alternatif untuk proses brazing, khususnya untuk logam Cu dengan bahan tambah Ag. Kata kunci : Biogas, Pressureized Storage, Brazing
AND THEMATIC INSTRUCTIONAL FOR PROSPECTIVE ELEMENTARY SCHOOL TEACHERS
Authors: Siahaan Parsaoran , Lyliyasari Ms 
Published: September 2016

This research, is part of a research on the development of a learning to improve mastery concept of science and the instructional. The learning model in this research integrate two courses with different subject and different semester in two PGSD of several campuses of an university of teacher training. PGSD-X, which is in the same city with the University and PGSD Y in other city at the same province. Subject of the research consisted of 25 prospective teacher students in PGSD X and 26 prospective teacher students in PGSD-Y. Scenario of learning was done in 4 phases, namely: (1) modeling phase, (2) discussions phase, (3) enrichment phase, and (4) peer teaching phase. The learning topics is the integration of food’s topic and thematic. The data was collected before learning (pre test) and after learning (post test). Data analysis was done by calculating the normalized gain from Hake <g>. The results from PGSD-X obtained <g>=0,72±0,07 in the mastery of food and <g>= 0,70±0,14 in thematic. The results from PGSD-Y obtained <g>=0,66±0,10 in the mastery of food and <g>=0,53±0,20 in thematic. The results could be concluded that the ability of prospective teachers in the PGSD X better than PGSD –Y in mastery of food concept and thematic instructional. Key words: learning model, prospective teachers, food, thematic
MENINGKATKAN KEMAMPUAN PEMECAHAN MASALAH MATEMATIS SISWA SEKOLAH MENENGAH ATAS MELALUI PEMBELAJARAN KOOPERATIF TIPE JIGSAW
Authors: Oktavien Yelli , Kusumah Yaya S , Dahlan Jarnawi A 
Published: September 2016

Tujuan penelitian ini adalah menelaah perbedaan peningkatan kemampuan pemecahan masalah matematis antara siswa yang mendapatkan pembelajaran kooperatif tipe Jigsaw dan siswa yang mendapatkan pembelajaran konvensional, serta sikap siswa terhadap pembelajaran kooperatif tipe Jigsaw. Desain penelitian yang digunakan adalah Pretest-Postest Control Group Design. Kelompok eksperimen memperoleh pembelajaran kooperatif tipe Jigsaw dan kelompok kontrol memperoleh pembelajaran konvensional. Untuk mendapatkan data hasil penelitian digunakan instrumen antara lain; tes kemampuan pemecahan masalah matematis dan skala sikap siswa. Penelitian ini dilakukan di Sekolah Menengah Atas dengan level tinggi. Populasi penelitian ini adalah siswa SMA Negeri 1 Rengat Propinsi Riau dengan responden penelitiannya adalah siswa kelas X sebanyak dua kelas yang dipilih secara acak kelas dari delapan yang ada. Dari hasil pengolahan data dengan menggunakan SPSS 16 uji normalitas dan uji beda dua rerata (uji-t') menunjukkan bahwa terdapat perbedaan peningkatan kemampuan pemecahan masalah matematis siswa yang mendapat pembelajaran kooperatif tipe Jigsaw dan siswa yang mendapat pembelajaran konvensional. Dapat disimpulkan bahwa pembelajaran dengan model kooperatif tipe Jigsaw secara signifikan dapat lebih meningkatkan kemampuan pemecahan masalah matematis siswa SMA dibandingkan dengan pembelajaran konvensional.Kata kunci: kemampuan pemecahan masalah matematis, pembelajaran kooperatif tipe Jigsaw
MODEL PEMBERIAN TUGAS RESITASI (M-APOS) YANG DILAKSANAKAN DENGAN BAHASA INGGRIS DALAM MENGEMBANGKAN KEMAMPUAN KOMUNIKASI MATEMATIS DAN KEPERCAYAAN DIRI MAHASISWA CALON GURU
Authors: Nurlaelah Elah 
Published: September 2016

Makalah ini menyajikan hasil observasi terhadap pembelajaran Aljabar Matrik yang menggunakan model M-APOS yang dilaksanakan dalam Bahasa Inggris untuk mengembangkan kemampuan komunikasi matematis dan kepercayaan diri mahasiswa calon guru. Implementasi pembelajaran menggunakan siklus ADL yang terdiri dari fase activities, fase class discussion dan fase exercises. Fase activities dalam penelitian dilaksanakan melalui tugas resitasi, dimana mahasiswa menyiapkan presentasi dengan memanfaatkan media power point dan menyajikannya dengan menggunakan bahasa inggris. Hasil pengamatan menunjukkan bahwa proses pembelajaran ini memberikan fasilitas dan kesempatan kepada mahasiswa untuk mengembangkan kemampuan mahaiswa dalam menumbuhkan kemampuan komunikasi matematis, belajar mandiri, menumbuhkan percaya diri dan memiliki tanggung jawab dalam menggali konsep yang harus dikuasainya. Hasil penelitian inipun menunjukkan bahwa aktivitas yang diberikan dapat menumbuhkan keterampilan menyajikan suatu materi dalam bentuk presentasi, memaksa mahasiswa untuk berkomunikasi matematika dengan bahasa inggris, dimana hal ini belum biasa dilaksanakan dalam perkuliahan umum. Kata Kunci : daya matematis, model pembelajaran M-APOS, siklus ADL
PEMBELAJARAN FISIKA BERORIENTASI PHYSICS AND EVERYDAY THINKING (PET) DAN EMOTIONAL INTELLIGENCE (EI) UNTUK MENINGKATKAN PEMAHAMAN KONSEP SISWA SMP
Authors: Nurmalasari Irma 
Published: September 2016

Penelitian dilatarbelakangi fakta bahwa rendahnya kemampuan pemahaman konsep dan terdapatnya anggapan negatif siswa terhadap mata pelajaran Fisika. Di lain pihak, pemahaman konsep dan perilaku positif merupakan tuntutan yang harus dimiliki oleh siswa SMP. Salah satu upaya yang dilakukan untuk mengatasi hal tersebut adalah dengan merancang suatu pembelajaran berorientasi kurikulum Physics and Everyday Thinking (PET) dan kompetensi kecerdasan emosional atau Emotional Intelligence (EI). Tujuan penelitian ini adalah untuk meningkatkan pemahaman konsep dan mengetahui profil EI. Instrumen yang digunakan untuk mengukur keterlaksanaan pembelajaran adalah observasi terhadap aktivitas guru dan siswa, untuk pemahaman konsep digunakan pilihan ganda beralasan, serta untuk profil EI digunakan observasi dan angket. Peningkatan pemahaman konsep siswa ditunjukkan melalui N-gain, sedangkan untuk profil EI dan keterlaksanaan pembelajaran ditunjukkan melalui interpretasi skor ke dalam tabel kategori. Metode yang digunakan dalam penelitian adalah kuasi eksperimen dengan desain penelitian One group pre-test and Post-test Design. Teknik pengambilan data yang digunakan adalah purposive sample dengan subjek penelitian siswa kelas VIII di SMP Negeri kota Bandung. Hasil penelitian menunjukkan adanya peningkatan pemahaman konsep siswa setelah pembelajaran dengan N-gain untuk masing-masing aspek adalah 0,70 untuk translasi dengan kategori tinggi; 0,48 untuk interpretasi dengan kategori sedang; dan 0,47 untuk ekstrapolasi dengan kategori sedang. Sementara itu untuk profil kecerdasan emosional siswa diperoleh hasil dengan kategori tinggi dengan rata-rata observasi 79% dan skor angket 78. Profil ini menunjukkan bahwa sebagian besar siswa memiliki potensi kecerdasan emosional yang baik untuk mendukung kemampuannya dalam bidang akademik.Kata kunci: fisika, pemahaman konsep, physics and everyday thinking (PET), kecerdasan emosional