Structurally specific thermal fluctuations identify functional sites for DNA transcription

We report results showing that thermally-induced openings of double stranded DNA coincide with the location of functionally relevant sites for transcription. Investigating both viral and bacterial DNA gene promoter segments, we found that the most probable opening occurs at the transcription start site. Minor openings appear to be related to other regulatory sites. Our results suggest that coherent thermal fluctuations play an important role in the initiation of transcription. Essential elements of the dynamics, in addition to sequence specificity, are nonlinearity and entropy, provided by local base-pair constraints

Double Distribution of Dark Matter Halos with respect to Mass and Local Overdensity

We present a double distribution function of dark matter halos, with respect to both object mass and local over- (or under-) density. This analytical tool provides a statistical treatment of the properties of matter surrounding collapsed objects, and can be used to study environmental effects on hierarchical structure formation. The size of the "local environment" of a collapsed object is defined to depend on the mass of the object. The Press-Schechter mass function is recovered by integration of our double distribution over the density contrast. We also present a detailed treatment of the evolution of overdensities and underdensities in Einstein-deSitter and flat LCDM universes, according to the spherical evolution model. We explicitly distinguish between true and linearly extrapolated overdensities and provide conversion relations between the two quantities.Comment: 25 pages, 10 figures, comments welcom

The retarding ion mass spectrometer on dynamics Explorer-A

An instrument designed to measure the details of the thermal plasma distribution combines the ion temperature-determining capability of the retarding potential analyzer with the compositional capabilities of the mass spectrometer and adds multiple sensor heads to sample all directions relative to the spacecraft ram directions. The retarding ion mass spectrometer, its operational modes and calibration are described as well as the data reduction plan, and the anticipated results

Comparison of air displacement plethysmography to hydrostatic weighing for estimating total body density in children

BACKGROUND: The purpose of this study was to examine the accuracy of total body density and percent body fat (% fat) using air displacement plethysmography (ADP) and hydrostatic weighing (HW) in children. METHODS: Sixty-six male and female subjects (40 males: 12.4 ± 1.3 yrs, 47.4 ± 14.8 kg, 155.4 ± 11.9 cm, 19.3 ± 4.1 kg/m(2); 26 females: 12.0 ± 1.9 yrs, 41.4 ± 7.7 kg, 152.1 ± 8.9 cm, 17.7 ± 1.7 kg/m(2)) were tested using ADP and HW with ADP always preceding HW. Accuracy, precision, and bias were examined in ADP with HW serving as the criterion method. Lohman's equations that are child specific for age and gender were used to convert body density to % fat. Regression analysis determined the accuracy of ADP and potential bias between ADP and HW using Bland-Altman analysis. RESULTS: For the entire group (Y = 0.835x + 0.171, R(2 )= 0.84, SEE = 0.007 g/cm(3)) and for the males (Y = 0.837x + 0.174, R(2 )= 0.90, SEE = 0.006 g/cm(3)) the regression between total body density by HW and by ADP significantly deviated from the line of identity. However in females, the regression between total body density by HW and ADP did not significantly deviate from the line of identity (Y = 0.750x + 0.258, R(2 )= 0.55, SEE = 0.008 g/cm(3)). The regression between % fat by HW and ADP for the group (Y = 0.84x + 3.81, R(2 )= 0.83, SEE = 3.35 % fat) and for the males (Y = 0.84x + 3.25, R(2 )= 0.90, SEE = 3.00 % fat) significantly deviated from the line of identity. However, in females the regression between % fat by HW and ADP did not significantly deviate from the line of identity (Y = 0.81x + 5.17, R(2 )= 0.56, SEE = 3.80 % fat). Bland-Altman analysis revealed no bias between HW total body density and ADP total body density for the entire group (R = 0.-22; P = 0.08) or for females (R = 0.02; P = 0.92), however bias existed in males (R = -0.37; P ≤ 0.05). Bland-Altman analysis revealed no bias between HW and ADP % fat for the entire group (R = 0.21; P = 0.10) or in females (R = 0.10; P = 0.57), however bias was indicated for males by a significant correlation (R = 0.36; P ≤ 0.05), with ADP underestimating % fat at lower fat values and overestimating at the higher % fat values. CONCLUSION: A significant difference in total body density and % fat was observed between ADP and HW in children 10–15 years old with a potential gender difference being detected. Upon further investigation it was revealed that the study was inadequately powered, thus we recommend that larger studies that are appropriately powered be conducted to better understand this potential gender difference

Dualism in the Labor Market: A Perspective on the Lewis Model After Half a Century

This paper asks how the Lewis model might be viewed from the perspective of economic science half a century later. Many of the core propositions remain intact, some might be amplified, and a small number might be revised

Establishment of novel neuroendocrine carcinoma patient-derived xenograft models for receptor peptide-targeted therapy

Gastroenteropancreatic neuroendocrine neoplasms (GEP NENs) are rare cancers consisting of neuroendocrine carcinomas (NECs) and neuroendocrine tumors (NETs), which have been increasing in incidence in recent years. Few cell lines and pre-clinical models exist for studying GEP NECs and NETs, limiting the ability to discover novel imaging and treatment modalities. To address this gap, we isolated tumor cells from cryopreserved patient GEP NECs and NETs and injected them into the flanks of immunocompromised mice to establish patient-derived xenograft (PDX) models. Two of six mice developed tumors (NEC913 and NEC1452). Over 80% of NEC913 and NEC1452 tumor cells stained positive for Ki67. NEC913 PDX tumors expressed neuroendocrine markers such as chromogranin A (CgA), synaptophysin (SYP), and somatostatin receptor-2 (SSTR2), whereas NEC1452 PDX tumors did not express SSTR2. Exome sequencing revealed loss o