Characterization of Metastatic Tumor Formation by the Colony Size Distribution

Knowledge regarding the kinetics of metastatic tumor formation, as related to the growth of the primary tumor, represents a fundamental issue in cancer biology. Using an in vivo mammalian model, we show here that one can obtain useful information from the frequency distribution of the sizes of metastatic colonies in distant organs after serial sectioning and image reconstruction. To explain the experimental findings, we constructed a biophysical model based on the respective growth patterns of the primary tumor and metastases and a stochastic process of metastatic colony formation. Heterogeneous distributions of various biological parameters were considered. We found that the elementary assumption of exponential forms of growth for the primary tumor and metastatic colonies predicts a linear relation on a log-log plot of a metastatic colony size distribution, which was consistent with the experimental results. Furthermore, the slope of the curve signifies the ratio of growth rates of the primary and the metastases. Non-exponential (Gompertzian and logistic) tumor growth patterns were also incorporated into the theory to explain possible deviation from the log-log linear relation. The observed metastasis-free probability also supported the assumption of a time-dependent Poisson process. With this approach, we determined the mechanistic parameters governing the process of metastatogenesis in the lungs for two murine tumor cell lines (KHT and MCaK). Since biological parameters specified in the model could be obtained in the laboratory, a workable metastatic "assay" may be established for various malignancies and in turn contribute in formulating rational treatment regimens for subclinical metastases.Comment: 14 pages, 6 figure

Royal Coachman (41CM111) An Early Middle Archaic Site along Cordova Creek in Comal County, Texas

The Royal Coachman site, 41CM111, is bisected by FM 306 near the highway’s eastern crossing of the Guadalupe River. Archeologists from the Texas Department of Transportation conducted extensive excavations at the site in 1980 and the Center for Archaeological Research carried out fieldwork related to geomorphic assessment of the deposits in 2002. The site contains at least three archeological components, an upper zone that may be of late Middle Archaic age and two commingled lower zones that are early Middle Archaic in age and contain a mix of Nolan/ Pandale and Bell-Andice/Early Triangular points. The deeper, more strongly manifested archeological components are associated with a dense burned rock sheet midden composed of two in situ features among a dense scatter of highly disturbed burned rock. Radiocarbon assays place this zone at between 5320–5880 years BP. The lithic assemblage is suggestive of tool manufacture and retooling activities and the projectile point collection is dominated by Early Triangular points and preforms. It is the recommendation of CAR that site 41CM111 warrants designation as a State Archeological Landmark and is eligible for listing on the National Register of Historic Places because of its significant contribution to a better understanding of the regional archeological record. We believe that these investigations have resulted in an appropriate level of work to evaluate the archeological property within the highway ROW and no further work is currently recommended. We also recommend that TxDOT consider avoidance as an option during future construction activities to avert impact to remaining deposits. In addition, if new ROW is acquired, additional work is warranted to determine the extent and significance of currently unidentified material. This work was conducted under Texas Antiquities Committee Permit No. 2807

Quasiparticle thermal Hall angle and magnetoconductance in YBa_2Cu_3O_x

We present a way to extract the quasiparticle (qp) thermal conductivity Kappa_e and mean-free-path in YBa_2Cu_3O_x, using the thermal Hall effect and the magnetoconductance of Kappa_e. The results are very consistent with heat capacity experiments. Moreover, we find a simple relation between the thermal Hall angle Theta_Q and the H-dependence of Kappa_e, as well as numerical equality between Theta_Q and the electrical Hall angle. The findings also reveal an anomalously anisotropic scattering process in the normal state.Comment: 4 pages in Tex, 5 figures in EPS; replaced on 5/12/99, minor change

What Caused the Significant Increase in Atlantic Ocean Heat Content Since the mid-20th Century?

As the upper layer of the world ocean warms gradually during the 20th century, the inter-ocean heat transport from the Indian to Atlantic basin should be enhanced, and the Atlantic Ocean should therefore gain extra heat due to the increased upper ocean temperature of the inflow via the Agulhas leakage. Consistent with this hypothesis, instrumental records indicate that the Atlantic Ocean has warmed substantially more than any other ocean basin since the mid-20th century. A surface-forced global ocean-ice coupled model is used to test this hypothesis and to find that the observed warming trend of the Atlantic Ocean since the 1950s is largely due to an increase in the inter-ocean heat transport from the Indian Ocean. Further analysis reveals that the increased inter-ocean heat transport is not only caused by the increased upper ocean temperature of the inflow but also, and more strongly, by the increased Agulhas Current leakage, which is augmented by the strengthening of the wind stress curl over the South Atlantic and Indian subtropical gyre

A method for determining venous contribution to BOLD contrast sensory activation

While BOLD contrast reflects haemodynamic changes within capillaries serving neural tissue, it also has a venous component. Studies that have determined the relation of large blood vessels to the activation map indicate that veins are the source of the largest response, and the most delayed in time. It would be informative if the location of these large veins could be extracted from the properties of the functional responses, since vessels are not visible in BOLD contrast images. The present study describes a method for investigating whether measures taken from the functional response can reliably predict vein location, or at least be useful in down-weighting the venous contribution to the activation response, and illustrates this method using data from one subject. We combined fMRI at 3 Tesla with high-resolution anatomical imaging and MR venography to test whether the intrinsic properties of activation time courses corresponded to tissue type. Measures were taken from a gamma fit to the functional response. Mean magnitude showed a significant effect of tissue type (P veins ≈ grey matter > white matter. Mean delays displayed the same ranking across tissue types (P grey matter. However, measures for all tissue types were distributed across an overlapping range. A logistic regression model correctly discriminated 72% of the veins from grey matter in the absence of independent information of macroscopic vessels (ROC=0.72). Whilst tissue classification was not perfect for this subject, weighting the T contrast by the predicted probabilities materially reduced the venous component to the activation map

Long-Acting Injectable Statins-Is It Time for a Paradigm Shift?

In recent years, advances in pharmaceutical processing technologies have resulted in development of medicines that provide therapeutic pharmacokinetic exposure for a period ranging from weeks to months following a single parenteral administration. Benefits for adherence, dose and patient satisfaction have been witnessed across a range of indications from contraception to schizophrenia, with a range of long-acting medicines also in development for infectious diseases such as HIV. Existing drugs that have successfully been formulated as long-acting injectable formulations have long pharmacokinetic half-lives, low target plasma exposures, and low aqueous solubility. Of the statins that are clinically used currently, atorvastatin, rosuvastatin, and pitavastatin may have compatibility with this approach. The case for development of long-acting injectable statins is set out within this manuscript for this important class of life-saving drugs. An overview of some of the potential development and implementation challenges is also presented

Polarity and ferromagnetism in two-dimensional hybrid copper perovskites with chlorinated aromatic spacers

We would like to thank the China Scholarships Council for a studentship to CH. PSH and WZ thank the Welch Foundation (Grant E-1457) and the National Science Foundation (DMR-2002319) for support.Two-dimensional (2D) organic−inorganichybrid copper perovskites have drawn tremendous attention as promisingmultifunctional materials. Herein, by incorporating ortho, metaand para-chlorine substitution in the benzylamine structure, we firstlyreport theinfluence of positional isomerism on the crystal structures of chlorobenzylammonium copper (II) chloride perovskites A2CuCl4. 2Dpolar ferromagnets (3-ClbaH)2CuCl4 and (4-ClbaH)2CuCl4(ClbaH+ = chlorobenzylammonium) are successfully obtained. They bothadopt a polar monoclinic space group Cc at room temperature, displayingsignificant differences in crystal structures. In contrast, (2-ClbaH)2CuCl4adopts a centrosymmetric space group P21/c at roomtemperature. This associated structural evolution successfullyenhances the physical properties of the two polar compounds with high thermalstability, discernible second harmonic generation (SHG) signals, ferromagnetism,and narrowoptical band gaps.These findings demonstrate that theintroduction of chlorine atoms into the inter-layer organicspecies is a powerful tool to tune crystalsymmetries and physical properties, and this inspires further exploration of designinghigh-performance multifunctional copper-based materials.Publisher PDFPeer reviewe

Calorimetric and Rheological Measurements of Three Commercial Thermosetting Prepreg Epoxies

The cure kinetics of three different thermosetting resins are investigated using differential scanning calorimetry and oscillatory shear rheometry. For the latter, two different types of plates are used, smooth plates and grooved plates; the latter are used to improve sample–plate contact. In addition, oscillatory compression rheology is used; however, machine compliance prevents accurate measurements at high conversions. A fractional conversion is defined based on the maximum storage modulus achieved at a given temperature, and is compared to the fractional conversion calculated from enthalpy measurements. As expected, the rates of reaction derived from these fractional conversions are very different for calorimetry and rheometry. However, the rates of reaction using the two types of plates are identical, although the grooved plates give much more reproducible storage moduli. A number of previously used mathematical expressions are employed to fit the calorimetric and rheological data, and the activation energies calculated from these fits are compared.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline