On the Dichotomy between the Nodal and Antinodal Excitations in High-temperature Superconductors

Angle-resolved photoemission data on optimally- and under-doped high temperature superconductors reveal a dichotomy between the nodal and antinodal electronic excitations. In this paper we propose an explanation of this unusual phenomenon by employing the coupling between the quasiparticle and the commensurate/incommensurate magnetic excitations.Comment: 11 pages, 9 figure

KUANTIFIKASI HAMBUR BALIK AKUSTIK DASAR LAUT MENGGUNAKAN SCIENTIFIC SINGLE BEAM ECHOSOUNDER

Hydroacoustic technology was able to quantify the seabed substrate and can be estimated accurately and near real time on the acoustic characters of each substrate. The purpose of research is to quantify the acoustic backscatters of the seabed substrate in an effort to devolop marine information technology. Data acquisition was using the Simrad EK-15 Single Beam Echosounder acoustic instrument set at a frequency of 200 kHz. Data processing and analysis includes acoustic backscatter strength, sediment type, acoustic bottom backscattering computation of seabed substrate and spatial analysis of seabed acoustic backscatter in the Lancang Island waters. The results of this study indicate that the acoustic backscatter values of the seabed substrate based on the SS value and particle size at each sampling station are -21.08 to -24.55 dB for type of substrate sands, fine sands are -25.67 to -26.67 dB, and very fine sands ranging from -27.42 to -28.03 dB. Based on the range of acoustic backscatter values ​​obtained from the sampling stations, type of seabed substrates along the survey line are very coarse sand, coarse sand, medium sand, fine sand, very fine sand, coarse silt, medium silt, fine silt, coarse clay and fine clay in the range values ​​of -47.85 to -17.07 dB. Sand substrates were dominant over silt and cly at the study site. Acoustic backscatter strength is strongly influenced by particle size, morphology and seabed relief.Teknologi hidroakustik mampu melakukan kuantifikasi terhadap substrat dasar laut dan dapat memperkirakan secara akurat dan mendekati real time terhadap karakter akustik yang dimiliki oleh masing-masing jenis substrat. Tujuan dari penelitian ini adalah melakukan kuantifikasi hambur balik akustik dasar laut dalam upaya pengembangan teknologi informasi kelautan. Akusisi data menggunakan instrumen akustik Single Beam Echosounder Simrad EK-15 pada frekuensi 200 kHz. Pengolahan dan analisis data meliputi hambur balik akustik, tipe sedimen, komputasi acoustics bottom backscattering substrat dasar laut dan analisis spasial acoustic backscattering dasar laut di perairan Pulau Lancang. Hasil penelitian ini menunjukkan bahwa nilai hambur balik akustik substrat dasar laut berdasarkan nilai SS dan ukuran partikel di setiap stasiun sampling yaitu tipe substrat pasir -21,08 dB sampai -24,55 dB, pasir halus -25,67 dB sampai -26,67 dB, dan pasir halus sekali berkisar antara -27,42 dB sampai -28,03 dB. Berdasarkan rentang nilai hambur balik akustik yang didapatkan dari stasiun sampling diperoleh klasifikasi jenis substrat dasar laut di sepanjang lajur survei yaitu pasir kasar sekali, pasir kasar, pasir sedang, pasir halus, pasir halus sekali, lanau kasar, lanau sedang, lanau halus, lempung kasar dan lempung halus pada rentang nilai -47,85 dB sampai -17,07 dB. Substrat pasir paling banyak ditemukan di lokasi penelitian dengan komposisi yang lebih besar dibandingkan dengan lanau dan lempung. Nilai hambur balik akustik sangat dipengaruhi oleh ukuran partikel, bentuk morfologi dan relief dasar laut

Working memory and high-level cognition in children: An analysis of timing and accuracy in complex span tasks

This study examined working memory (WM) using complex span tasks (CSTs) to improve theoretical understanding of the relationship between WM and high-level cognition (HLC) in children. Ninety-two children aged between seven and eight years were tested on three computer-paced CSTs and measures of non-verbal reasoning, reading and mathematics. Processing times in the CSTs were restricted based on individually titrated processing speeds, and performance was compared to participant-led tasks with no time restrictions. Storage, processing accuracy, and both processing and recall times within the CSTs were used as performance indices to understand the effects of time restrictions at a granular level. Restricting processing times did not impair storage, challenging models that argue for a role of maintenance in WM. A task-switching account best explained the effect of time restrictions on performance indices and their inter-relationships. Principal component analysis showed that a single factor with all performance indices from just one CST (Counting span) was the best predictor of HLC. Storage in both the participant-led and computer-paced versions of this task explained unique and shared variance in HLC. However, the latter accounted for more variance in HLC when contributions from processing time were included in the model. Processing time in this condition also explained variance above and beyond storage. This suggests that faster processing is important to keep information active in WM; however, this is only evident when time restrictions are placed on the task and important when WM performance is applied in broader contexts that rely on this resource

Children’s Verbal, Visual and Spatial Processing and Storage Abilities: An Analysis of Verbal Comprehension, Reading, Counting and Mathematics

The importance of working memory (WM) in reading and mathematics performance has been widely studied, with recent research examining the components of WM (i.e., storage and processing) and their roles in these educational outcomes. However, the differing relationships between these abilities and the foundational skills involved in the development of reading and mathematics have received less attention. Additionally, the separation of verbal, visual and spatial storage and processing and subsequent links with foundational skills and downstream reading and mathematics has not been widely examined. The current study investigated the separate contributions of processing and storage from verbal, visual and spatial tasks to reading and mathematics, whilst considering influences on the underlying skills of verbal comprehension and counting, respectively. Ninety-two children aged 7- to 8-years were assessed. It was found that verbal comprehension (with some caveats) was predicted by verbal storage and reading was predicted by verbal and spatial storage. Counting was predicted by visual processing and storage, whilst mathematics was related to verbal and spatial storage. We argue that resources for tasks relying on external representations of stimuli related mainly to storage, and were largely verbal and spatial in nature. When a task required internal representation, there was a draw on visual processing and storage abilities. Findings suggest a possible meaningful separability of types of processing. Further investigation of this could lead to the development of an enhanced WM model, which might better inform interventions and reasonable adjustments for children who struggle with reading and mathematics due to WM deficits

Land Use Implications of Expanding Biofuel Demand

The Renewable Fuel Standard mandates in the Energy Independence and Security Act of 2007 will require 36 billion gallons of ethanol to be produced in 2022. The mandates require that 16 of the 36 billion gallons must be produced from cellulosic feedstocks. The potential land use implications resulting from these mandates were examined using two methods, the POLYSYS model and a general equilibrium model. Results of the POLYSYS analysis indicated that 72.1 million tons of corn stover, 23.5 million tons of wheat straw, and 24.7 million acres would be used to produce 109 million tons of switchgrass in 2025 to meet the mandate. Results of the CGE analysis indicated that 10.9 billion bushels of corn grain, 71 million tons of corn stover, and 56,200 tons of switchgrass is needed to meet the mandate.cellulosic ethanol, corn stover, grain ethanol, renewable fuel standard, switchgrass, Crop Production/Industries, Demand and Price Analysis, Environmental Economics and Policy, Land Economics/Use, Resource /Energy Economics and Policy, Q15, Q42,

Audit of failure rate of sulfadoxine/pyrimethamine combined with chloroquine to treat falciparum malaria at single fourteen-day follow-up

Objective. To assess the failure rate of the present first line treatment regime for uncomplicated falciparum malaria of sulfadoxine/pyrimethamine combined with chloroquine. Design. A before-after study1 Setting. Ndumo Clinic, Ingwavuma District, South Africa, October 2000 Study Group. 55 patients presenting to Ndumo clinic with uncomplicated malaria and malaria trophozoites visible on thin film. Main outcome measures:Trophozoite count on thick film at day 14. Results. 15 out of 37 patients who returned for follow-up still had trophozoites on thick film. Symptoms of most patients at day 0 and day 14 were mild, parasite counts before and after treatment were low, and trophozoites were atypical. Conclusions. There appears to be an unacceptably high day 14 failure rate with the combination of sulfadoxine/pyrimethamine and chloroquine.The mildness of symptoms, low parasite counts and atypical trophozoites suggest immunity to falciparum malaria amongst the local population. With few antimalarials to chose from, the difficult question as to future treatment of uncomplicated malaria arises. Keywords: Falciparum malaria, chloroquine, sulfadoxine, pyrimethamine SA Fam Prac Vol.25(3) 2002: 4-