Travelling waves in a tissue interaction model for skin pattern formation

Tissue interaction plays a major role in many morphogenetic processes, particularly those associated with skin organ primordia. We examine travelling wave solutions in a tissue interaction model for skin pattern formation which is firmly based on the known biology. From a phase space analysis we conjecture the existence of travelling waves with specific wave speeds. Subsequently, analytical approximations to the wave profiles are derived using perturbation methods. We then show numerically that such travelling wave solutions do exist and that they are in good agreement with our analytical results. Finally, the biological implications of our analysis are discussed

Sequential pattern formation in a model for skin morphogenesis

During morphogenesis regular patterns often develop behind a frontier of pattern formation which travels across the prospective tissue. Here the authors consider the propagating patterns exhibited in a two-dimensional domain by a tissue interaction mechanochemical model for skin pattern formation. It is shown that the model can exhibit travelling waves of complex spatial pattern formation. Two alternative mechanisms that can produce such sequential patterning are presented. In particular, it is demonstrated that the specification of a simple quasi-one-dimensional pattern is all that is required to determine a complex two-dimensional pattern. Finally, the model solutions are related to actual pattern propagation during chick feather primordia initiation

Modeling scenarios for water allocation in the Gediz Basin, Turkey

Water management / Water allocation / Models / River basin development / Hydrology / Decision making / Environmental effects / Water use efficiency / Climate / Irrigation water / Irrigated farming / Stream flow / Surface water / Salt water intrusion / Turkey / Gediz Basin

An analysis of the fevers met with among Europeans in Calcutta: with a brief account of their clinical features and treatment

I propose to give here, a brief account of the most important fevers met with among Europeans resident in Calcutta.having been on the staff of the large European hospital there for over four years, I have had ample opportunity for studying clinically a large number of such cases, and it is chiefly from the clinical point of view that I wish to write, giving, at the same time examples of each type with the temperature charts.I need hardly say, that among medical cases, "fever" is by far the most common complaint for which a patient comes to hospital. Therefore it is important to be able to differentiate the various fever both from the point of view of treatment and prognosi There undoubtedly was, some years ago, and still is, but to a less extent I am glad to say, a tendency to consider all fevers malarial, and to dose the unfortunate patient with quinine. This is a most - valuable drug when given in suitable cases, but one which has, without doubt, been much abused in the tropics.The most important fevers met with are malaria and typhoid, others being kala-azar, heat -stroke, and a peculiar fever, resembling in some respects dengue, spoken of generally in Calcutta as "seven -day fever ". This name was first given to it by Major Rogers, I.N.S on account of its average duration to about seven days.There are still undifferentiated fevers to be me with, but more accurate methods of diagnosis have already, and will further, reduce their number

Characterization of the CBC2 readout ASIC for the CMS strip-tracker high-luminosity upgrade

The CMS Binary Chip 2 (CBC2) is a full-scale prototype ASIC developed for the front-end readout of the high-luminosity upgrade of the CMS silicon strip tracker. The 254-channel, 130 nm CMOS ASIC is designed for the binary readout of double-layer modules, and features cluster-width discrimination and coincidence logic for detecting high-PT track candidates. The chip was delivered in January 2013 and has since been bump-bonded to a dual-chip hybrid and extensively tested. The CBC2 is fully functional and working to specification: we present the result of electrical characterization of the chip, including gain, noise, threshold scan and power consumption, together with the performance of the stub finding logic. Finally we will outline the plan for future developments towards the production version

Chandra Observations of "The Antennae" Galaxies (NGC 4038/39)

We report the results of a deep Chandra ACIS pointing at the merging system NGC 4038/39. We detect an extraordinarily luminous population of X-ray sources, with luminosity well above that of XRBs in M31 and the Milky Way. If these sources are unbeamed XRBs, our observations may point to them being 10-100Mo black hole counterparts. We detect an X-ray bright hot ISM, with features including bright superbubbles associated with the actively star-forming knots, regions where hot and warm (H$\alpha$) ISM intermingle, and a large-scale outflow.Comment: 7 pages, 10 figures, Accepted for publication in Ap