Advanced turbine engine mainshaft lubrication system investigation. Part 2 - Detailed face seals performance, mass spectroscopic study of a test fluid, and supplementary test data Final report

Face seal performance, mass spectroscopic test fluid study and supplementary test data for supersonic turbine engine mainshaft lubrication syste

An analytic model for the epoch of halo creation

In this paper we describe the Bayesian link between the cosmological mass function and the distribution of times at which isolated halos of a given mass exist. By assuming that clumps of dark matter undergo monotonic growth on the time-scales of interest, this distribution of times is also the distribution of `creation' times of the halos. This monotonic growth is an inevitable aspect of gravitational instability. The spherical top-hat collapse model is used to estimate the rate at which clumps of dark matter collapse. This gives the prior for the creation time given no information about halo mass. Applying Bayes' theorem then allows any mass function to be converted into a distribution of times at which halos of a given mass are created. This general result covers both Gaussian and non-Gaussian models. We also demonstrate how the mass function and the creation time distribution can be combined to give a joint density function, and discuss the relation between the time distribution of major merger events and the formula calculated. Finally, we determine the creation time of halos within three N-body simulations, and compare the link between the mass function and creation rate with the analytic theory.Comment: 7 pages, 2 figures, submitted to MNRA

Attraction of Acorn-Infesting \u3ci\u3eCydia Latiferreana\u3c/i\u3e (Lepidoptera: Tortricidae) to Pheromone-Baited Traps

Males of acorn-infesting Cydia latiferreana are attracted to an equilibrium mixture of the four isomers of 8, 10-dodecadien-l-ol acetate, the virgin female-produced pheromone. Trap height relative to the height of trees in which traps are placed seems to be a significant factor influencing moth catches at attractant-baited traps. In an oak woodlot and in an oak nursery, catches of male moths were greater in traps placed near the upper periphery of the canopy than at traps deployed at lower levels in the tree. Practical application of pheromone-baited traps in a forest situation will require further study on lure formulation and on trap deployment under forest conditions

An imaging K-band survey - I: The catalogue, star and galaxy counts

We present results from a large area (552\,\sqamin) imaging $K$-band survey to a 5$\sigma$ limit of $K\simeq 17.3$. We have optical-infrared colours of almost all the objects in the sample. Star-galaxy discrimination is performed and the results used to derive the infrared star and galaxy counts. $K$-band ``no-evolution'' galaxy-count models are constructed and compared with the observed data. In the infrared, there is no counterpart for the large excess of faint galaxies over the no-evolution model seen in optical counts. However, we show that the $K$ counts can be remarkably insensitive to evolution under certain reasonable assumptions. Finally, model predictions for $K$-selected redshift surveys are derived.Comment: MNRAS in press. 21 pages plain TeX; figs plus table 4 available via anonymous ftp from /pub/kgb/paper1/sissa.uu at ftp.ast.cam.ac.u

Reionization Revisited: Secondary CMB Anisotropies and Polarization

Secondary CMB anisotropies and polarization provide a laboratory to study structure formation in the reionized epoch. We consider the kinetic Sunyaev-Zel'dovich effect from mildly nonlinear large-scale structure and show that it is a natural extension of the perturbative Vishniac effect. If the gas traces the dark matter to overdensities of order 10, as expected from simulations, this effect is at least comparable to the Vishniac effect at arcminute scales. On smaller scales, it may be used to study the thermal history-dependent clustering of the gas. Polarization is generated through Thomson scattering of primordial quadrupole anisotropies, kinetic (second order Doppler) quadrupole anisotropies and intrinsic scattering quadrupole anisotropies. Small scale polarization results from the density and ionization modulation of these sources. These effects generically produce comparable E and B-parity polarization, but of negligible amplitude (0.001-0.01 uK) in adiabatic CDM models. However, the primordial and kinetic quadrupoles are observationally comparable today so that a null detection of B-polarization would set constraints on the evolution and coherence of the velocity field. Conversely, a detection of a cosmological B-polarization even at large angles does not necessarily imply the presence of gravity waves or vorticity. For these calculations, we develop an all-sky generalization of the Limber equation that allows for an arbitrary local angular dependence of the source for both scalar and symmetric trace-free tensor fields on the sky.Comment: 14 pages, 12 figures, minor changes and typo fixes reflect published versio

Identification of Novel HIF1A Target Genes That Regulate Tumor Progression and Metastasis

Hypoxia is a hallmark of most solid tumors. In response to hypoxic stress tumor cells adapt by regulating survival, metabolism and angiogenesis. The heterodimeric HypoxiaInducible Factor (HIF) transcription factors are the master regulators of this response. HIFs play key roles in many critical aspects of cancer biology including angiogenesis, stem cell maintenance, metabolic reprogramming, invasion, metastasis and resistance to radiation therapy and chemotherapy. Overexpression of HIF-1α and HIF-2α has been documented in multiple human cancers and HIF-1 protein is over-expressed in ~30% of primary breast tumors and ~70% of metastases, which independently correlates with poor prognosis and decreased survival in patients. A precise role for HIF-2 in breast cancer is still being elucidated. Our lab has established primary mammary tumor epithelial cells (MTECs) from late stage carcinomas originating in PyMT+; Hif1a floxed mice. These MTECs were exposed to either Adenovirus-beta-gal or -Cre to create wild-type (WT) and knockout (KO) cells, respectively. Deletion of HIF-1 activity reduced primary tumor growth by ~60% and the formation of lung macrometastases originating from mammary fat pad tumors by \u3e90%. In addition, deletion of Hif1a reduced mammary tumorsphere formation efficiency (TSE) in vitro and tumor initiating cell (TIC) frequency in vivo. In contrast, in triple negative models of breast cancer, knockdown of HIF1A had the opposite phenotype, increasing TSE in vitro and increased primary mammary tumor growth in vivo. ITGA6 (CD49f) was identified as one HIF-1α-dependent cancer stem cell marker that enriches for both primary mammary tumor growth and metastasis to the lung. Microarray profiling conducted to identify genes differentially expressed between PyMT WT and KO cells and end-stage WT and KO tumors revealed several genes that were down-regulated in both data sets in response to deletion of Hif1a. One mRNA of particular interest, creatine kinase brain isoform (Ckb) was down-regulated in KO cells \u3e100 fold and \u3e2 fold in end-stage tumors. Transplantation of Ckb knockdown (KD) PyMT cells to the mammary fat pad delayed initiation of palpable tumors by \u3e30 days. When cells were introduced into the circulation via tail vein injection, 20% of mice injected with Ckb KD cells developed lung metastases whereas 100% of mice injected with WT cells developed metastases. Likewise, when mice injected with WT PyMT cells were treated daily with a CKB chemical inhibitor, cyclocreatine (cCr), lungs of vehicle treated (saline) mice were almost completely covered with surface metastases, while lungs of cCr treated mice contained very few metastases. Overall, our data show that HIF-1α strongly promotes mammary tumor initiation, progression and metastasis, in part through regulation of TIC activity. Metastasis is the major cause of mortality in breast cancer patients. Further characterization of the distinct roles of HIF- 1α versus HIF-2α in breast cancer and metastasis, and genes downstream of the HIFs, such as ITGA6 (CD49f) and CKB, that play a key role in driving tumor initiation and invasion, are likely to identify new pathways amenable to therapeutic intervention for patients with metastatic breast cancer

A Sphinx on the American Land: The Nineteenth Century South in Comparative Perspectives

Many souths Slim volume asserts broad comparative methodology in study of region Social anthropology has but one method; it is the comparative method; it is impossible pronounced Evans-Pritchard, the Oxford anthropologist. His point is that perfect comparisons are impossible, yet...

The Market for Drug-Free Poultry: Why Robust Regulation of Animal Raising Claims is the Right Prescription to Combat Antibiotic Resistance

Since their introduction in the mid-twentieth century, antibiotics have become a mainstay of poultry production for purposes ranging from growth promotion to disease treatment and control. Nevertheless, for almost as long, there have been concerns about the role that these agricultural uses play in the development of antibiotic resistant bacteria. The issue of antibiotic resistance in general is fast becoming a public health crisis and scrutiny of agriculture as a contributing cause continues. Nevertheless, to date, neither regulatory efforts to curb agricultural usage nor private sector actions in response to consumer demand and public-interest campaigns have led to significant changes in addressing the problem