Suppressed Andreev Reflection at the Normal-Metal / Heavy-Fermion Superconductor CeCoIn5_5 Interface

Dynamic conductance spectra are taken from Au/CeCoIn$_5$ point contacts in the Sharvin limit along the (001) and (110) directions. Our conductance spectra, reproducibly obtained over wide ranges of temperature, constitute the cleanest data sets ever reported for HFSs. A signature for the emerging heavy-fermion liquid is evidenced by the development of the asymmetry in the background in the normal state. Below $T_c$, an enhancement of the sub-gap conductance arising from Andreev reflection is observed, with the magnitude of $\sim$ 13.3 % and $\sim$ 11.8 % for the (001) and the (110) point contacts, respectively, an order of magnitude smaller than those observed in conventional superconductors but consistent with those in other HFSs. Our zero-bias conductance data for the (001) point contacts are best fit with the extended BTK model using the d-wave order parameter. The fit to the full conductance curve of the (001) point contact indicates the strong coupling nature ($2\Delta/k_{B}T_c = 4.64$). However, our observed suppression of both the Andreev reflection signal and the energy gap indicates the failure of existing models. We provide possible directions for theoretical formulations of the electronic transport across an N/HFS interface. Several qualitative features observed in the (110) point contacts provide the first clear spectroscopic evidence for the $d_{x^2-y^2}$ symmetry.Comment: 13 pages, 7 figures, LaTeX, paper invited and submitted to SPIE Conference on Strongly Correlated Electron Materials: Physics and Nanoengineering, in San Diego, California, July 31 - August 4, 200

Pencirian bakteria asid laktik dan sebatian aroma ikan pekasam

Dalam kajian ini, bakteria asid laktik (LAB) serta sebatian aroma ikan pekasam daripada spesies yang berbeza ditentukan. Persampelan ikan pekasam iaitu tilapia, loma, lampam, sepat dan gelama diperoleh daripada pembekal Perusahaan Ikan Pekasam Kiah di Kuala Kangsar, Perak. Penentuan spesies LAB dijalankan melalui kaedah pencairan bersiri, pengkulturan LAB, ujian katalase, ujian pewarnaan spora serta ujian pengesanan Gram bakteria dan morfologi. Pengesahan spesies LAB dijalankan melalui pengekstrakan asid deoksiribonukleik (DNA), amplifikasi dengan tindak balas rantaian polimerasi (PCR), analisis elektroforesis gel dan penjujukan DNA. Hasil jujukan DNA yang diperoleh dibandingkan dengan jujukan dalam pangkalan data GenBank di NCBI menggunakan BLAST. Didapati Lactobacillus brevis KB290 DNA dan Lactobacillus casei W56 wujud dalam pekasam tilapia, Lactobacillus plantarum 16 dalam pekasam lampam, Lactobacillus casei BD-II kromosom dan Lactobacillus plantarum WCFS1 dalam pekasam sepat, Corynebacterium vitaeruminis DSM 20294 dan Streptococcus anginosus C1051 dalam pekasam gelama. Manakala Staphylococcus carnosus subsp. carnosus TM300 kromosom adalah LAB dominan dalam pekasam loma. Sementara itu, sebatian aroma ditentukan melalui kaedah pengekstrakan cecair menggunakan pelarut metanol dan heksana. Pemprofilan sebatian aroma dijalankan dengan kromatografi gas-spektometer jisim (GC-MS). Sebatian aroma dalam ekstrak metanol dan heksana daripada lima jenis ikan pekasam dibandingkan. Bilangan sebatian aroma yang diekstrak menggunakan metanol adalah lebih banyak berbanding dengan yang menggunakan heksana. Sebatian aroma yang paling banyak dikesan adalah daripada pekasam loma. Asid karboksilik merupakan sebatian yang paling dominan dalam ikan pekasam dan memberi bau hamis serta tengik

Seaweed tea: fucoidan-rich functional food product development from Malaysian brown seaweed, Sargassum binderi

Our previous studies on fucoidan from Malaysian brown seaweed, Sargassum binderi, found that it exhibited significant secondary anti-oxidative activity and showed non-toxicity. In order to exploit its health benefits, fucoidan-rich seaweed tea was developed in this study. A total of 4 different brewing time treatments were performed on Sargassum binderi at 5, 10, 15 and 20 mins (Ft05, Ft10, Ft15 and Ft20, respectively). It was found that Ft20 showed significantly (p<0.05) highest fucoidan content (27.22 ± 0.07 mg/200 mL), superoxide anion scavenging activity (16.46 ± 2.83%) and hydroxyl radical scavenging activity (89.83 ± 4.11%) compared to that of Ft05, Ft10 and Ft15. Both the secondary antioxidant activities were significantly positive correlated to the fucoidan content tests (superoxide anion scavenging activity at r=0.97, p=0.0052; and hydroxyl radical scavenging activity at r=0.99, p=0.0011). Masking of the seaweed odour was performed using lemon essence and discriminative test found that masking was most effective using lemon essence at a concentration of 0.3% (v/v). Therefore, there is potential for this seaweed tea to be commercialised, thus, consumers may acquire the health benefit of fucoidan

Kesan kaedah pemendakan berbeza terhadap ciri fizikokimia dan aktiviti antioksidan alginat daripada Sargassum sp.

Alginat merupakan polisakarida berstruktur anionik yang terdapat dalam matriks alga perang dan lazimnya digunakan sebagai agen penggelan, pengemulsi dan penstabil dalam industri makanan. Objektif utama kajian dijalankan adalah untuk mengenal pasti kesan kaedah pemendakan berbeza terhadap ciri fizikokimia alginat. Dalam kajian ini, alginat telah diekstrak daripada Sargassum sp. dengan menggunakan dua kaedah pemendakan yang berbeza iaitu melalui pemendakan dengan garam kalsium dan asid (sampel A) dan juga pemendakan dengan asid dan etanol (sampel B). Analisis ATR-FTIR telah mengesahkan kehadiran alginat dalam kedua-dua ekstrak Sargassum sp. Hasil pengekstrakan alginat bagi sampel A dan sampel B masing-masing adalah 28.16% dan 18.24%. Ciri fizikokimia yang diuji ialah warna, kelikatan, aktiviti penggelan dan kuasa pemerangkapan radikal bebas DPPH dan dibandingkan dengan alginat komersial (Sigma-Aldrich). Alginat yang terhasil adalah berwarna kuning kecoklatan dan mempunyai kelikatan pseudoplastik dengan penipisan ricih. Aktiviti penggelan kedua-dua sampel (A & B) adalah berbeza secara signifikan, (p<0.05) dengan alginat komersial. Kuasa pemerangkapan radikal bebas DPPH sampel A adalah lebih tinggi berbanding alginat komersial (20.10 ±3.84 & 11.89 ±3.12). Secara keseluruhan, kaedah pemendakan sampel A adalah lebih baik berbanding sampel B disebabkan oleh hasil alginat yang tinggi, aktiviti antioksidan yang tinggi dan ciri fizikokimia yang hampir setanding dengan alginat komersial

To what extent has ASEAN succeeded in driving economic regionalism?

published_or_final_versionInternational and Public AffairsMasterMaster of International and Public Affair

Pliocene–Pleistocene basin evolution along the Garlock fault zone, Pilot Knob Valley, California

Exposed Pliocene–Pleistocene terrestrial strata provide an archive of the spatial and temporal development of a basin astride the sinistral Garlock fault in California. In the southern Slate Range and Pilot Knob Valley, an ∼2000-m-thick package of Late Cenozoic strata has been uplifted and tilted to the northeast. We name this succession the formation of Pilot Knob Valley and provide new chronologic, stratigraphic, and provenance data for these rocks. The unit is divided into five members that record different source areas and depositional patterns: (1) the lowest exposed strata are conglomeratic rocks derived from Miocene Eagle Crags volcanic field to the south and east across the Garlock fault; (2) the second member consists mostly of fine-grained rocks with coarser material derived from both southern and northern sources; and (3) the upper three members are primarily coarse-grained conglomerates and sandstones derived from the adjacent Slate Range to the north. Tephrochronologic data from four ash samples bracket deposition of the second member to 3.6–3.3 Ma and the fourth member to between 1.1 and 0.6 Ma. A fifth tephrochronologic sample from rocks south of the Garlock fault near Christmas Canyon brackets deposition of a possible equivalent to the second member of the formation of Pilot Knob Valley at ca. 3.1 Ma. Although the age of the base of the lowest member is not directly dated, regional stratigraphic and tectonic associations suggest that the basin started forming ca. 4–5 Ma. By ca. 3.6 Ma, the northward progradation fanglomerate sourced in the Eagle Crags region waned, and subsequent deposition occurred in shallow lacustrine systems. At ca. 3.3 Ma, southward progradation of conglomerates derived from the Slate Range began. Circa 1.1 Ma, continued southward progradation of fanglomerate with Slate Range sources is characterized by a shift to coarser grain sizes, interpreted to reflect uplift of the Slate Range. Overall, basin architecture and the temporal evolution of different source regions were controlled by activity on three regionally important faults—the Garlock, the Marine Gate, and the Searles Valley faults. The timing and style of motions on these faults appear to be directly linked to patterns of basin development

Inhibition of poly(ADP-ribose)polymerase binding to DNA by thymidine dimer

AbstractThe ability of poly(ADP-ribose)polymerase to bind damaged DNA was assessed by electrophoretic mobility shift assay. DNA binding domain of poly(ADP-ribose)polymerase (PARPDBD) binds to synthetic deoxyribonucleotide duplex 10-mer. However, the synthetic deoxyribonucleotide duplex containing cys-syn thymidine dimer which produces the unwinding of DNA helix structure lost its affinity to PARPDBD. It was shown that the binding of PARPDBD to the synthetic deoxyribonucleotide duplex was not affected by O6-Me-dG which causes only minor distortion of DNA helix structure. This study suggests that the stabilized DNA helix structure is important for poly(ADP-ribose)polymerase binding to DNA breaks, which are known to stimulate catalytic activity of poly(ADP-ribose)polymerase

Discovering Patient Phenotypes Using Generalized Low Rank Models

The practice of medicine is predicated on discovering commonalities or distinguishing characteristics among patients to inform corresponding treatment. Given a patient grouping (hereafter referred to as a p henotype ), clinicians can implement a treatment pathway accounting for the underlying cause of disease in that phenotype. Traditionally, phenotypes have been discovered by intuition, experience in practice, and advancements in basic science, but these approaches are often heuristic, labor intensive, and can take decades to produce actionable knowledge. Although our understanding of disease has progressed substantially in the past century, there are still important domains in which our phenotypes are murky, such as in behavioral health or in hospital settings. To accelerate phenotype discovery, researchers have used machine learning to find patterns in electronic health records, but have often been thwarted by missing data, sparsity, and data heterogeneity. In this study, we use a flexible framework called Generalized Low Rank Modeling (GLRM) to overcome these barriers and discover phenotypes in two sources of patient data. First, we analyze data from the 2010 Healthcare Cost and Utilization Project National Inpatient Sample (NIS), which contains upwards of 8 million hospitalization records consisting of administrative codes and demographic information. Second, we analyze a small (N=1746), local dataset documenting the clinical progression of autism spectrum disorder patients using granular features from the electronic health record, including text from physician notes. We demonstrate that low rank modeling successfully captures known and putative phenotypes in these vastly different datasets

Effect of hybridization composition and glycerin content on novel corn starch/nata de coco plastic film: Thermal, mechanical, and degradation study

The objective of this work was to develop a plastic film from food sources with excellent thermal, mechanical, and degradability performance. Corn starch (CS)/nata de coco (NDC) were hybridized with addition of glycerin as plasticizer at different weight ratio and weight percent, respectively. Sample analysis found that the hybridization of CS with NDC improved the film forming properties, mechanical and thermal, degradation properties, as well as hydrophobicity and solubility of the film up to 0.5:0.5 wt hybrid ratio. The properties of the films were highly affected by the homogeneity of the sample during hybridization, with high NDC amount (0.3:0.7 wt CS:NDC) showing poor hydrophobicity, and mechanical and thermal properties. The glycerin content, however, did not significantly affect the hydrophobicity, water solubility, and degradability properties of CS/NDC film. Hybridization of 0.5:0.5 wt CS/NDC with 2 phr glycerin provided the optimum Young’s modulus (15.67 MPa) and tensile strength (1.67 MPa) properties