Using 21-cm absorption surveys to measure the average HI spin temperature in distant galaxies

We present a statistical method for measuring the average HI spin temperature in distant galaxies using the expected detection yields from future wide-field 21cm absorption surveys. As a demonstrative case study we consider a simulated all-southern-sky survey of 2-h per pointing with the Australian Square Kilometre Array Pathfinder for intervening HI absorbers at intermediate cosmological redshifts between $z = 0.4$ and $1$. For example, if such a survey yielded $1000$ absorbers we would infer a harmonic-mean spin temperature of $\overline{T}_\mathrm{spin} \sim 100$K for the population of damped Lyman $\alpha$ (DLAs) absorbers at these redshifts, indicating that more than $50$ per cent of the neutral gas in these systems is in a cold neutral medium (CNM). Conversely, a lower yield of only 100 detections would imply $\overline{T}_\mathrm{spin} \sim 1000$K and a CNM fraction less than $10$ per cent. We propose that this method can be used to provide independent verification of the spin temperature evolution reported in recent 21cm surveys of known DLAs at high redshift and for measuring the spin temperature at intermediate redshifts below $z \approx 1.7$, where the Lyman-$\alpha$ line is inaccessible using ground-based observatories. Increasingly more sensitive and larger surveys with the Square Kilometre Array should provide stronger statistical constraints on the average spin temperature. However, these will ultimately be limited by the accuracy to which we can determine the HI column density frequency distribution, the covering factor and the redshift distribution of the background radio source population.Comment: 11 pages, 9 figures, 1 table. Proof corrected versio

Studi Dampak Masuknya PT. Donggi Senoro Terhadap Pengeluaran Konsumsi Rumah Tangga Di Kecamatan Kintom Kabupaten Banggai

This study aimed to describe the impact of the entry of PT.Donggi-Senoro LNG (DSLNG) against the living conditions of the people in the District Kintom, and analyze the influence of income, education, occupation, and number of dependents of the consumption expenditure of the poor in the District Kintom.Type of survey research, using cross section data obtained from interviews directly to the respondents using a questionnaire regarding the characteristics of the respondents.Sampling purposive sampling technique, so as to obtain the key respondents by 99 people.This study uses qualitative analysis to decipher the impact of the entry of PT.Donggi-Senoro LNG (DSLNG) on the living conditions of society, using multiple linear regression to see the influence of income, education, occupation, and number of dependents of the consumption expenditure of the poor in the District Kintom. Tools used to manage the data of this study was SPSS-21.Results of the study found that the impact of the entry of PT.Donggi - Senoro LNG (DSLNG), against the District Kintom people's living conditions, among others: the increase in income, employment, improving public education, and disruption of social processes.Medium for statistical analysis of the consumption of poor households shows that the coefficient of determination (R) for, 757 which means that the variation of independent variables RTM District of Kintom consumption by 75.70%.Significance Simultaneous detection (Test Statistic F) and obtained the F-table at 2.47 (α: 5%, and df: 99-4 = 95) while the statistical F/F-count of 31.462 and F-statistic probability value 0,000.Medium for Detection of Individual Parameter Significance (Test Statistics T) obtained t-table value of 1.661.Based on the t-table value with the assumption of the t-statistics/t count\u003e t-table, the independent variables were significant to the variable household consumption is variable income (t-test = 5.328), and the number of dependents (t-test = 3824).Based on the research results suggested to PT.DSLNG to be more structured in implementing CSR, and for the Government of the District Kintom need to create policies that can improve / increase the income of poor households are not able to meet the basic consumption needs in order to prosper and be able to meet their basic needs.And also suggested that the Government of the District Kintom more proactive in controlling the implementation of CSR given PT.DSLNG to society, so that more people benefit from CSR

Comprehensive Detection of Genes Causing a Phenotype using Phenotype Sequencing and Pathway Analysis

Discovering all the genetic causes of a phenotype is an important goal in functional genomics. In this paper we combine an experimental design for multiple independent detections of the genetic causes of a phenotype, with a high-throughput sequencing analysis that maximizes sensitivity for comprehensively identifying them. Testing this approach on a set of 24 mutant strains generated for a metabolic phenotype with many known genetic causes, we show that this pathway-based phenotype sequencing analysis greatly improves sensitivity of detection compared with previous methods, and reveals a wide range of pathways that can cause this phenotype. We demonstrate our approach on a metabolic re-engineering phenotype, the PEP/OAA metabolic node in E. coli, which is crucial to a substantial number of metabolic pathways and under renewed interest for biofuel research. Out of 2157 mutations in these strains, pathway-phenoseq discriminated just five gene groups (12 genes) as statistically significant causes of the phenotype. Experimentally, these five gene groups, and the next two high-scoring pathway-phenoseq groups, either have a clear connection to the PEP metabolite level or offer an alternative path of producing oxaloacetate (OAA), and thus clearly explain the phenotype. These high-scoring gene groups also show strong evidence of positive selection pressure, compared with strictly neutral selection in the rest of the genome

Astrometric Detection of Terrestrial Planets in the Habitable Zones of Nearby Stars with SIM PlanetQuest

SIM PlanetQuest (Space Interferometry Mission) is a space-borne Michelson interferometer for precision stellar astrometry, with a nine meter baseline, currently slated for launch in 2015. One of the principal science goals is the astrometric detection and orbit characterization of terrestrial planets in the habitable zones of nearby stars. Differential astrometry of the target star against a set of reference stars lying within a degree will allow measurement of the target star's reflex motion with astrometric accuracy of 1 micro-arcsecond in a single measurement. We assess SIM's capability for detection (as opposed to characterization by orbit determination) of terrestrial planets in the habitable zones of nearby solar-type stars. We compare SIM's performance on target lists optimized for the SIM and Terrestrial Planet Finder Coronograph (TPF-C) missions. Performance is quantified by three metrics: minimum detectable planet mass, number and mass distribution of detected planets, and completeness of detections in each mass range. Finally, we discuss the issue of confidence in detections and non-detections, and show how information from SIM's planet survey can enable TPF to increase its yield of terrestrial planets.Comment: Minor corrections to figures and tables. 46 pages, 27 figures. To appear in PASP (Publications of the Astronomical Society of the Pacific), May 200