Motional Broadening in Ensembles With Heavy-Tail Frequency Distribution

We show that the spectrum of an ensemble of two-level systems can be broadened through `resetting' discrete fluctuations, in contrast to the well-known motional-narrowing effect. We establish that the condition for the onset of motional broadening is that the ensemble frequency distribution has heavy tails with a diverging first moment. We find that the asymptotic motional-broadened lineshape is a Lorentzian, and derive an expression for its width. We explain why motional broadening persists up to some fluctuation rate, even when there is a physical upper cutoff to the frequency distribution.Comment: 6 pages, 4 figure

Kajian Faktor-faktor Penyebab Ketidakefektifan Kinerja Terminal Bus Haumeni Kota Soe Kabupaten Timor Tengah Selatan

Terminal Haumeni yang terletak di Kota Soe adalah salah satu contoh prasarana transportasi yang kinerjanya tidak efektif karena angkutan umum lebih banyak melakukan aktifitasnya di luar terminal. Berdasarkan pengamatan, persimpangan dekat lokasi terminal yang dijadikan sebagai terminal bayangan. Kajian ini bertujuan untuk mengetahui faktor-faktor yang mempengaruhi ketidakefektifan kinerja terminal bus Haumeni dengan statistik Skala Likert. Dari hasil analisis, berdasarkan persepsi pengguna jasa, faktor-faktor yang mempengaruhi ketidakefektifan kinerja terminal bus Haumeni adalah tidak adanya bus yang masuk ke terminal dengan persentase sikap penumpang 68,60 %, lokasi terminal yang kurang strategis dengan persentase penumpang 57,91 %, pengemudi 76,84 %, fasilitas terminal yang kurang efektif dengan persentase penumpang 76,74 %, pengemudi 62,11 %, kurangnya pelayanan petugas terminal dengan persentase penumpang 58,14 %, pengemudi 74,74 %, tidak adanya peraturan yang berlaku bagi pengguna jasa dengan persentase penumpang 63,26 %, tidak ada pengawasan dari pihak keamanan dengan persentase penumpang 65,58 %, pengemudi 66,32 %, parkir yang tidak teratur dengan persentase penumpang 62,79 %, pengemudi 65,26 %. Haumeni terminal which is located in the city of Soe is one example of a transport infrastructure that performance is not effective because the public transport is turns more to do it outside the terminal. Based on the observation, the intersection near the location of the terminal that serve as a shadow terminal. This study aims to determine the factors that affect the performance of ineffectivenes Haumeni bus terminal using descriptive statistical analysis of the Likert Scale. From the analysis based on the user perception of services, the factors that affect the performance of the bus terminal Haumeni ineffectiveness is the lack of buses to load passenger in terminal with a percentage of 68.60% of passenger attitudes, less strategic terminal locations with a percentage of 57.91% attitude passengers, driver 76.84%, terminal facilities were less effective with the percentage of 76.74% and the attitude of the driver's passenger 62.11%, the lack of service personnel attitude passenger terminal with the percentage 58.14% and 74.74% driver, the absence of regulations for service user with a percentage attitude 63.26% passenger, there is not oversight of the security forces with the percentage of 65.58% attitude passenger and the driver 66.32%, irregular parking arrangement with the percentage of 62.79% and the attitude of the driver's passenger 65.26%

A computational interactome and functional annotation for the human proteome

We present a database, PrePPI (Predicting Protein-Protein Interactions), of more than 1.35 million predicted protein-protein interactions (PPIs). Of these at least 127,000 are expected to constitute direct physical interactions although the actual number may be much larger (~500,000). The current PrePPI, which contains predicted interactions for about 85% of the human proteome, is related to an earlier version but is based on additional sources of interaction evidence and is far larger in scope. The use of structural relationships allows PrePPI to infer numerous previously unreported interactions. PrePPI has been subjected to a series of validation tests including reproducing known interactions, recapitulating multi-protein complexes, analysis of disease associated SNPs, and identifying functional relationships between interacting proteins. We show, using Gene Set Enrichment Analysis (GSEA), that predicted interaction partners can be used to annotate a protein’s function. We provide annotations for most human proteins, including many annotated as having unknown function

Spectropolarimetry of SN 2011dh in M51: geometric insights on a Type IIb supernova progenitor and explosion

We present seven epochs of spectropolarimetry of the Type IIb supernova (SN) 2011dh in M51, spanning 86 days of its evolution. The first epoch was obtained 9 days after the explosion, when the photosphere was still in the depleted hydrogen layer of the stripped-envelope progenitor. Continuum polarization is securely detected at the level of P~0.5% through day 14 and appears to diminish by day 30, which is different from the prevailing trends suggested by studies of other core-collapse SNe. Time-variable modulations in P and position angle are detected across P-Cygni line features. H-alpha and HeI polarization peak after 30 days and exhibit position angles roughly aligned with the earlier continuum, while OI and CaII appear to be geometrically distinct. We discuss several possibilities to explain the evolution of the continuum and line polarization, including the potential effects of a tidally deformed progenitor star, aspherical radioactive heating by fast-rising plumes of Ni-56 from the core, oblique shock breakout, or scattering by circumstellar material. While these possibilities are plausible and guided by theoretical expectations, they are not unique solutions to the data. The construction of more detailed hydrodynamic and radiative-transfer models that incorporate complex aspherical geometries will be required to further elucidate the nature of the polarized radiation from SN 2011dh and other Type IIb supernovae.Comment: Post-proof edit. Accepted to MNRAS 2015 Aug 1

Effects of anisotropic spin-exchange interactions in spin ladders

We investigate the effects of the Dzialoshinskii-Moriya (DM) and Kaplan-Shekhtman-Entin-Wohlman-Aharony (KSEA) interactions on various thermodynamic and magnetic properties of a spin 1/2 ladder. Using the Majorana fermion representation, we derive the spectrum of low energy excitations for a pure DM interaction and in presence of a superimposed KSEA interaction. We calculate the various correlation functions for both cases and discuss how they are modified with respect to the case of an isotropic ladder. We also discuss the electron spin resonance (ESR) spectrum of the system and show that it is strongly influenced by the orientation of the magnetic field with respect to the Dzialoshinskii-Moriya vector. Implications of our calculations for NMR and ESR experiments on ladder systems are discussed.Comment: 14 pages, 4 eps figures, corrected calculation of NMR rate (v3

Dyskeratosis Congenita links telomere attrition to age-related systemic energetics.

Underlying mechanisms of plasma metabolite signatures of human ageing and age-related diseases are not clear but telomere attrition and dysfunction are central to both. Dyskeratosis Congenita (DC) is associated with mutations in the telomerase enzyme complex (TERT, TERC, and DKC1) and progressive telomere attrition. We analyzed the effect of telomere attrition on senescence associated metabolites in fibroblast conditioned media and DC patient plasma. Samples were analyzed by gas chromatography/ mass spectrometry and liquid chromatography/ mass spectrometry. We showed extracellular citrate was repressed by canonical telomerase function in vitro and associated with DC leukocyte telomere attrition in vivo; leading to the hypothesis that altered citrate metabolism detects telomere dysfunction. However, elevated citrate and senescence factors only weakly distinguished DC patients from controls, whereas elevated levels of other tricarboxylic acid cycle metabolites, lactate and especially pyruvate distinguished them with high significance. The DC plasma signature most resembled that of patients with loss of function pyruvate dehydrogenase complex mutations and that of older subjects but significantly not those of type 2 diabetes, lactic acidosis, or elevated mitochondrial reactive oxygen species (1-3). Additionally, our data are consistent with further metabolism of citrate and lactate in the liver and kidneys. Citrate uptake in certain organs modulates age-related disease in mice and our data has similarities with age-related disease signatures in humans. Our results have implications for the role of telomere dysfunction in human ageing in addition to its early diagnosis and the monitoring of anti-senescence therapeutics, especially those designed to improve telomere function