Nebular models of sub-chandrasekhar mass type ia supernovae: Clues to the origin of ca-rich transients

We use non-local thermal equilibrium radiative transport modeling to examine observational signatures of sub- Chandrasekhar mass double detonation explosions in the nebular phase. Results range from spectra that look like typical and subluminous Type Ia supernovae (SNe) for higher mass progenitors to spectra that look like Ca-rich transients for lower mass progenitors. This ignition mechanism produces an inherent relationship between emission features and the progenitor mass as the ratio of the nebular [Ca II]/[Fe III] emission lines increases with decreasing white dwarf mass. Examining the [Ca II]/[Fe III] nebular line ratio in a sample of observed SNe we find further evidence for the two distinct classes of SNe Ia identified in Polin et al. by their relationship between Si II velocity and B-band magnitude, both at time of peak brightness. This suggests that SNe Ia arise from more than one progenitor channel, and provides an empirical method for classifying events based on their physical origin. Furthermore, we provide insight to the mysterious origin of Ca-rich transients. Low-mass double detonation models with only a small mass fraction of Ca (1%) produce nebular spectra that cool primarily through forbidden [Ca II] emission

Biomarkers for late-onset neonatal sepsis

The diagnosis of healthcare-associated infections is problematic because of the overlap between clinical signs associated with 'normal' physiological disturbances and those of bacteremia or fungemia. Earlier diagnosis of sepsis in critically ill infants would enable timely administration of antibiotics and discontinuation of treatment in infants with a low probability of sepsis. A recent study by Ng et al. identified two novel biomarkers for late-onset neonatal sepsis: the des-arginine variant of serum amyloid A and apolipoprotein C-II. These markers may be of value in the identification of neonates with bacteremia or fungemia

Gravitational Wave Hotspots: Ranking Potential Locations of Single-Source Gravitational Wave Emission

The steadily improving sensitivity of pulsar timing arrays (PTAs) suggests that gravitational waves (GWs) from supermassive black hole binary (SMBHB) systems in the nearby universe will be de- tectable sometime during the next decade. Currently, PTAs assume an equal probability of detection from every sky position, but as evidence grows for a non-isotropic distribution of sources, is there a most likely sky position for a detectable single source of GWs? In this paper, a collection of galactic catalogs is used to calculate various metrics related to the detectability of a single GW source resolv- able above a GW background, assuming that every galaxy has the same probability of containing a SMBHB. Our analyses of these data reveal small probabilities that one of these sources is currently in the PTA band, but as sensitivity is improved regions of consistent probability density are found in predictable locations, specifically around local galaxy clusters.Comment: 9 pages, 9 figures, accepted for submission in Ap

Myosin II filament dynamics in actin networks revealed with interferometric scattering microscopy

The plasma membrane and the underlying cytoskeletal cortex constitute active platforms for a variety of cellular processes. Recent work has shown that the remodeling acto-myosin network modifies local membrane organization, but the molecular details are only partly understood due to difficulties with experimentally accessing the relevant time and length scales. Here, we use interferometric scattering (iSCAT) microscopy to investigate a minimal acto-myosin network linked to a supported lipid bilayer membrane. Using the magnitude of the interferometric contrast, which is proportional to molecular mass, and fast acquisition rates, we detect, and image individual membrane attached actin filaments diffusing within the acto-myosin network and follow individual myosin II filament dynamics. We quantify myosin II filament dwell times and processivity as functions of ATP concentration, providing experimental evidence for the predicted ensemble behavior of myosin head domains. Our results show how decreasing ATP concentrations lead to both increasing dwell times of individual myosin II filaments and a global change from a remodeling to a contractile state of the acto-myosin network

Usulan Penataan Pedagang Kaki Lima di Kawasan Lapangan Merdeka Medan

Merdeka Square is a public open space which is intended for all people. Public open space is a place as a general basis where people carry out functional and ritual activities that bind the community, both in the normal routine of daily life or in periodic celebrations. Merdeka Square is a place frequented by some of the citizens of Medan City. Even visitors from outside Medan came to take time to stop at Merdeka Square when certain events were held at Merdeka Square. This is what attracts people - certain people use the crowd to become the potential to run a business. So it is not surprising that in the Merdeka Square area at certain events and days it will be crowded not only with the presence of visitors to Merdeka Square, but also the presence of the informall sector such as street vendors. The purpose of this study is to obtain or produce a design proposal to organize the Street Vendors in the Merdeka Square Area in hopes of increasing comfort for visitors in the Merdeka Square Area

Colloidal Electrostatic Interactions Near a Conducting Surface

Charge-stabilized colloidal spheres dispersed in deionized water are supposed to repel each other. Instead, artifact-corrected video microscopy measurements reveal an anomalous long-ranged like-charge attraction in the interparticle pair potential when the spheres are confined to a layer by even a single charged glass surface. These attractions can be masked by electrostatic repulsions at low ionic strengths. Coating the bounding surfaces with a conducting gold layer suppresses the attraction. These observations suggest a possible mechanism for confinement-induced attractions.Comment: 4 pages, 2 figure

Persepsi Penghuni terhadap Kenyamanan Beraktivitas di Ruang Terbuka Perumahan

A comfort open space has a function and a huge influence in housing because it becomes a means of activity throughout the housing dwellers. Debang Housing Taman Sari Medan is one of housing in Kecamatan Medan Selayang which has open space. The purpose of this research is to know the perception of occupant to the comfort of open space. There are several convenience factors that are used as indicators in research such as Circulation, Climate, Noise, Smell, Shape, Safety, Cleanliness, and Beauty. The research was done through qualitative descriptive analysis, where the data collection technique used questionnaire from the population and the specified sample. The process of collecting data, sampling technique until the criteria of research become an important process of research method. This study shows if the perception of occupants of the comfort of open space of housing Debang Taman Sari Medan is quite comfortable and needed supporting facilities for park users

A longitudinal analysis of the hot hand and gambler’s fallacy biases

Researchers have found evidence of both hot hand and gambler’s fallacy biases in lottery number selection. Which of the two opposite effects is observed is often dependent upon the nature of the lottery game, the particular sample, the local culture of the participants, or the time transpired since the seed event. By observing hundreds of millions of lottery entries over 118 consecutive semiweekly drawings, we present evidence of both effects and their longitudinal properties. With respect to the selection of individual numbers, lottery participants tend to avoid recently selected winning numbers. This gambler’s fallacy effect diminishes and the number becomes increasingly ‘hot’ until it is selected again. With respect to winning number combinations, we found strong evidence of a small but persistent hot hand bias. This bias gradually diminishes over time, but remains detectable and highly consistent for a number of years