Testing the presence of multiple photometric components in nearby early-type galaxies using SDSS

We investigate two-dimensional image decomposition of nearby, morphologically selected early-type galaxies (ETGs). We are motivated by recent observational evidence of significant size growth of quiescent galaxies and theoretical development advocating a two-phase formation scenario for ETGs. We find that a significant fraction of nearby ETGs show changes in isophotal shape that require multi-component models. The characteristic sizes of the inner and outer component are $\sim 3$ and $\sim 15$ kpc. The inner component lies on the mass-size relation of ETGs at $z \sim 0.25-0.75$, while the outer component tends to be more elliptical and hints at a stochastic buildup process. We find real physical differences between the single- and double-component ETGs, with the double-component galaxies being younger and more metal-rich. The fraction of double component ETGs increases with increasing $\sigma$ and decreases in denser environments. We hypothesize that double-component systems were able to accrete gas and small galaxies until later times, boosting their central densities, building up their outer parts, and lowering their typical central ages. In contrast, the oldest galaxies, perhaps due to residing in richer environments, have no remaining hints of their last accretion episode.Comment: resubmitted to ApJ after referee's repor

Tests of Inference for Dummy Variables in Regressions with Logarithmic Transformed Dependent Variables

The interpretation of dummy variables in regressions where the dependent variable is subject to a log transformation has been of continuing interest in economics. However, in the main, these earlier papers do not deal with the inferential aspects of the parameters estimated. In this paper we compare the inference implied by the hypotheses tested on the linear parameter estimated in the model and the tests applied to the proportional change that this parameter implies. An important element in this analysis is the asymmetry introduced by the log transformation. Suggestions are made for the appropriate test procedure in this case. Examples are presented from some common econometric applications of this model in the estimation of hedonic price models and wage equations.Hypothesis tests;lognormal distribution; measures of proportional change; wage equation; hedonic price model

Clustering in a Data Envelopment Analysis Using Bootstrapped Efficiency Scores

This paper explores the insight from the application of cluster analysis to the results of a Data Envelopment Analysis of productive behaviour. Cluster analysis involves the identification of groups among a set of different objects (individuals or characteristics). This is done via the definitions of a distance matrix that defines the relationship between the different objects, which then allows the determination of which objects are most similar into clusters. In the case of DEA, cluster analysis methods can be used to determine the degree of sensitivity of the efficiency score for a particular DMU to the presence of the other DMUs in the sample that make up the reference technology to that DMU. Using the bootstrapped values of the efficiency measures we construct two types of distance matrices. One is defined as a function of the variance covariance matrix of the scores with respect to each other. This implies that the covariance of the score of one DMU is used as a measure of the degree to which the efficiency measure for a single DMU is influenced by the efficiency level of another. An alternative distance measure is defined as a function of the ranks of the bootstrapped efficiency. An example is provided using both measures as the clustering distance for both a one input one output case and a two input two output case.

Inferences for the Extremum of Quadratic Regression Models

Quadratic functions are often used in regression to infer the existence of an extremum in a relationship although tests of the location of the extremum are rarely performed. We investigate the construction of the following confidence intervals: Delta, Fieller, estimated first derivative, bootstrapping, Bayesian and likelihood ratio. We propose interpretations for the unbounded intervals that may be generated by some of these methods. The coverage of the confidence intervals is assessed by Monte Carlo; the Delta and studentized bootstrap can perform quite poorly. Of all the methods, the first derivative method is easiest to implement.Inverted U-Shaped, turning point, Fieller method, Delta method, 1st derivative function, Bayesian, Likelihood ratio, Bootstrap.

Mid-Infrared Colors of Dwarf Galaxies: Young Starbursts Mimicking Active Galactic Nuclei

Searching for active galactic nuclei (AGN) in dwarf galaxies is important for our understanding of the seed black holes that formed in the early Universe. Here, we test infrared selection methods for AGN activity at low galaxy masses. Our parent sample consists of ~18,000 nearby dwarf galaxies (M*< 3 x 10^9 Msun, $z<0.055$) in the Sloan Digital Sky Survey with significant detections in the first three bands of the AllWISE data release from the Wide-field Infrared Survey Explorer (WISE). First, we demonstrate that the majority of optically-selected AGNs in dwarf galaxies are not selected as AGNs using WISE infrared color diagnostics and that the infrared emission is dominated by the host galaxies. We then investigate the infrared properties of optically-selected star-forming dwarf galaxies, finding that the galaxies with the reddest infrared colors are the most compact, with blue optical colors, young stellar ages and large specific star formation rates. These results indicate that great care must be taken when selecting AGNs in dwarf galaxies using infrared colors, as star-forming dwarf galaxies are capable of heating dust in such a way that mimics the infrared colors of more luminous AGNs. In particular, a simple $\mathrm{W1}-\mathrm{W2}$ color cut alone should not be used to select AGNs in dwarf galaxies. With these complications in mind, we present a sample of 41 dwarf galaxies worthy of follow-up observations that fall in WISE infrared color space typically occupied by more luminous AGNs.Comment: 17 pages, 12 figures, accepted by the Astrophysical Journa

Categories of insight and their correlates: An exploration of relationships among classic-type insight problems, rebus puzzles, remote associates and esoteric analogies.

A central question in creativity concerns how insightful ideas emerge. Anecdotal examples of insightful scientific and technical discoveries include Goodyear's discovery of the vulcanization of rubber, and Mendeleev's realization that there may be gaps as he tried to arrange the elements into the Periodic Table. Although most people would regard these discoveries as insightful, cognitive psychologists have had difficulty in agreeing on whether such ideas resulted from insights or from conventional problem solving processes. One area of wide agreement among psychologists is that insight involves a process of restructuring. If this view is correct, then understanding insight and its role in problem solving will depend on a better understanding of restructuring and the characteristics that describe it. This article proposes and tests a preliminary classification of insight problems based on several restructuring characteristics: the need to redefine spatial assumptions, the need to change defined forms, the degree of misdirection involved, the difficulty in visualizing a possible solution, the number of restructuring sequences in the problem, and the requirement for figure-ground type reversals. A second purpose of the study was to compare performance on classic spatial insight problems with two types of verbal tests that may be related to insight, the Remote Associates Test (RAT), and rebus puzzles. In doing so, we report on the results of a survey of 172 business students at the University of Waikato in New Zealand who completed classic-type insight, RAT and rebus problems

Interpretative Works of the d-Sup Protein within the Tardigrade Genome

Tardigrades, also known as water bears, are microscopic creatures that happen to have extreme radiotolerancy. Because of this, they are able to withstand the most extreme conditions. This radiotolerancy has been pinpointed to the d-Sup protein and has thus instigated experimentations into the limits and availability to genetically splice this protein and its functions have been tested. Through analysis and critique of these studies, I have created art pieces to express the scientific research and findings. Each piece varies in scientific data, alongside media and size. This results in an assemblage of works that will successfully express scientific research and findings in a visual mode. It is fair to note that the current global pandemic of Covid-19 has halted some of this artistic expression and presented obstacles that were not always overcome. Because of this, there’s limitation on wholly finished pieces—further explained in the body of this project

Lifestyle and Consumers’ Choice of Laundry Services in Manado City: An Empirical Study

Lifestyle, including activities, interests, and opinions, influences consumer shopping behaviour and decisions in laundry businesses. It relates to individual’s way of life, use of money and time, expressed in activities, interests, and opinions. Therefore, those partaking in this business need to understand their consumers’ lifestyle, for complete information on what products to offer, innovate, and promote. This study was conducted in Malalayang, Paal 2, Boulevard, and the areas surrounding Sam Ratulangi Airport, the central areas of modern laundry businesses in Manado. The findings suggest that lifestyle simultaneously conferred a positive and significant effect on consumer’s laundry service preference. Therefore, every related dimension, including activities, interests, and opinions, also significantly affects the parameter under investigation

Food prices and obesity: long-run effect in US metropolitan areas

Once considered as a serious public health issue only in developed countries, now overweight and obesity have dramatically increased in low- and middle-income countries, especially in urban settings (WHO, 2008). The main purpose of this study is to explore the economic incentives for this rapid growth in obesity rates, by studying variations in obesity over time and across geographic regions in the United States. Although a number of researchers and policymakers have devoted significant resources to address the recent rapid rise in obesity in the United States, âthe prevalence of overweight and obesity has increased sharply since the mid 1970sâ (Centers for Disease Control, 2008) and most of this increase occurred in the 1980s and 1990s (Cutler, et al., 2003). More importantly, changes in food prices have also occurred over the past 30 years and have occurred simultaneously with the obesity epidemic (Finkelstein, et al., 2005). In this study, we investigate how the decline in food prices in the last three decades affects the long-run growth of obesity rates. We take the advantage of the large panel data that cover for the time periods with the fastest growth of obesity rates, by using metropolitan samples from the National Health Interview Survey (NHIS) and information on prices of food at home and food away from home from these major metropolitan areas for years 1976 to 2001. Specifically, instead of using absolute food prices, we explore the impacts from changes in relative prices of food at home and food away from home (i.e. food prices relative to prices for a market basket of consumer goods and services in these metropolitan areas), as well as changes in prices of food at home and food away from home on the growth in obesity rates during this time frame. We also control for the changes in contextual factors and changes in value of female in these metropolitan areas. Our findings reveal the important fact that changes in relative food prices can explain about 20 percent of the obesity growth during this time period and such effect is more pronounced for the low-educated. The results of the study provide an interpretation of the long-run growth of obesity rates in urban settings.Consumer/Household Economics, Food Consumption/Nutrition/Food Safety, Health Economics and Policy,