Momentum and Heat Transfer Studies. I. Transfer of Heat and Momentum in Uniform Turbulent Air Streams. II. Continuous Velocity Measurements by the Hot Wire Method

Part I The thermal flux has been measured across an air stream flowing in a uniform, two-dimensional manner between horizontal parallel plates at different temperatures. Reynolds numbers ranged from 9,800 to 56,500. A macroscopic correlation shows the effect of turbulence on the thermal transfer. A revised correlation of total conductivity as a function of position is subsequently obtained by correcting previously deter­mined values of total conductivity. A similar correlation of the total viscosity with position is revised to allow for variation in the pressure gradient with plate separation. The correlations fall off with increasing Reynolds number. The turbulent Prandtl numbers for two tests by an earlier investigator are compared with those predicted from the ratio of the revised point correlations. Part II Two hot-wire methods are described for determining continuously the mean velocity as a function of position in a turbulently-flowing air stream. In the constant-resistance method the mean wire temperature is automatically controlled. In the constant-current method no control is necessary. In exploratory measurements the total viscosities bridge the discontinuous gap which arises from the use of von Kármán's expression at the boundary between the buffer layer and the turbulent core. Thermal flux corresponding to a Nusselt number of 40 has no noticeable effect on the velocity profile.</p

A 2012 Social Accounting Matrix (SAM) for South Africa

This paper documents the construction of a South African Social Accounting Matrix (SAM) for the year 2012. The SAM is built using a Statistics South Africa Supply Table and Use Table, National Accounts, and various household and labour market surveys. It provides a detailed representation of the South African economy and identifies 62 activities and 104 commodities; labour is disaggregated by education attainment level; and households by per capita expenditure deciles. Information on labour is drawn from the 2012 Labour Market Dynamics Survey of the Quarterly Labour Force Survey. Data on households is taken from the 2008/9 Living Conditions Survey. The SAM identifies government, investment, and foreign accounts. It is a useful database for conducting economy-wide impact assessments, including SAM-based multiplier analysis and computable general equilibrium modelling

Deciphering the Roles of Multicomponent Recognition Signals by the AAA+ Unfoldase ClpX

ATP-dependent protein remodeling and unfolding enzymes are key participants in protein metabolism in all cells. How these often-destructive enzymes specifically recognize target protein complexes is poorly understood. Here, we use the well-studied AAA + unfoldase-substrate pair, Escherichia coli ClpX and MuA transposase, to address how these powerful enzymes recognize target protein complexes. We demonstrate that the final transposition product, which is a DNA-bound tetramer of MuA, is preferentially recognized over the monomeric apo-protein through its multivalent display of ClpX recognition tags. The important peptide tags include one at the C-terminus (“C-tag”) that binds the ClpX pore and a second one (enhancement or “E-tag”) that binds the ClpX N-terminal domain. We construct a chimeric protein to interrogate subunit-specific contributions of these tags. Efficient remodeling of MuA tetramers requires ClpX to contact a minimum of three tags (one C-tag and two or more E-tags), and that these tags are contributed by different subunits within the tetramer. The individual recognition peptides bind ClpX weakly (K[subscript D] > 70 μM) but impart a high-affinity interaction (K[subscript D] ~ 1.0 μM) when combined in the MuA tetramer. When the weak C-tag signal is replaced with a stronger recognition tag, the E-tags become unnecessary and ClpX's preference for the complex over MuA monomers is eliminated. Additionally, because the spatial orientation of the tags is predicted to change during the final step of transposition, this recognition strategy suggests how AAA + unfoldases specifically distinguish the completed “end-stage” form of a particular complex for the ideal biological outcome.National Institutes of Health (U.S.) (Grants GM-49224 and AI-16892)National Institutes of Health (U.S.) (NIH Pre-Doctoral Training Grant T32GM007287

Towards Neutrino Mass from Cosmology without Optical Depth Information

With low redshift probes reaching unprecedented precision, uncertainty of the CMB optical depth is expected to be the limiting factor for future cosmological neutrino mass constraints. In this paper, we discuss to what extent combinations of CMB lensing and galaxy surveys measurements at low redshifts $z\sim 0.5-5$ will be able to make competitive neutrino mass measurements without relying on any optical depth constraints. We find that the combination of LSST galaxies and CMB-S4 lensing should be able to achieve constraints on the neutrino mass sum of 25meV without optical depth information, an independent measurement that is competitive with or slightly better than the constraint of 30meV possible with CMB-S4 and present-day optical depth measurements. These constraints originate both in structure growth probed by cross-correlation tomography over a wide redshift range as well as, most importantly, the shape of the galaxy power spectrum measured over a large volume. We caution that possible complications such as higher-order biasing and systematic errors in the analysis of high redshift galaxy clustering are only briefly discussed and may be non-negligible. Nevertheless, our results show that new kinds of high-precision neutrino mass measurements at and beyond the present-day optical depth limit may be possible.Comment: 8 pages, 6 figure

Immunolocalisation of phosphorylated STAT3, interleukin 11 and leukaemia inhibitory factor in endometrium of women with unexplained infertility during the implantation window.

BACKGROUND: Uterine receptivity and embryo implantation are critical in the establishment of pregnancy. The diagnosis of endometrial fertility requires more precise measurements of endometrial receptivity. Interleukin (IL-11) and leukemia inhibitory factor (LIF) are essential for murine implantation and signal via intracellular phosphorylation (p) of STAT3 in the endometrium. Both cytokines are present in the endometrium of women duiring the receptive window. Endometrial IL-11, IL-11 receptor alpha (IL-11Ralpha), LIF and pSTAT3 in women with primary unexplained infertility was compared to normal fertile women during the implantation window. METHODS: LH timed endometrial biopsies (LH+6 to LH+10) were collected from women with unexplained infertility and normal fertility. pSTAT3, IL-11, IL-11Ralpha and LIF production was determined by immunohistochemistry. Staining intensity was determoned by two independent observers blind to the fertility status of the patient from whom the biopsy was taken. Staining intensity and heterogeneity in each of the endometrial compartments (epithelium; stroma, including decidualized stromal cells; and vasculature) was assessed. The Mann-Whitney U test was used to analyze IL-11, pSTAT3, IL-11Ralpha and LIF immunostaining intensities in the samples. RESULTS: IL-11, IL-11Ralpha and LIF were present predominantly in glandular epithelium, whilst luminal epithelium showed patchy staining. pSTAT3 was present in both glandular epithelium and stroma. IL-11 and pSTAT3 immunostaining was significantly lower in glandular epithelium in infertile women compared to controls (P < 0.05) whilst IL-11Ralpha and LIF staining did not differ. CONCLUSION: This is the first demonstration of reduced endometrial pSTAT3 and IL-11 in some women with unexplained infertility. This suggests IL-11 and pSTAT3 may be involved in the secretory transformation of glandular epithelium during receptivity. Reduced IL-11 production and STAT3 phosphorylation may contribute to unexplained infertility in some women.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are