Stochastic Continuous Time Neurite Branching Models with Tree and Segment Dependent Rates

In this paper we introduce a continuous time stochastic neurite branching model closely related to the discrete time stochastic BES-model. The discrete time BES-model is underlying current attempts to simulate cortical development, but is difficult to analyze. The new continuous time formulation facilitates analytical treatment thus allowing us to examine the structure of the model more closely. We derive explicit expressions for the time dependent probabilities p(\gamma, t) for finding a tree \gamma at time t, valid for arbitrary continuous time branching models with tree and segment dependent branching rates. We show, for the specific case of the continuous time BES-model, that as expected from our model formulation, the sums needed to evaluate expectation values of functions of the terminal segment number \mu(f(n),t) do not depend on the distribution of the total branching probability over the terminal segments. In addition, we derive a system of differential equations for the probabilities p(n,t) of finding n terminal segments at time t. For the continuous BES-model, this system of differential equations gives direct numerical access to functions only depending on the number of terminal segments, and we use this to evaluate the development of the mean and standard deviation of the number of terminal segments at a time t. For comparison we discuss two cases where mean and variance of the number of terminal segments are exactly solvable. Then we discuss the numerical evaluation of the S-dependence of the solutions for the continuous time BES-model. The numerical results show clearly that higher S values, i.e. values such that more proximal terminal segments have higher branching rates than more distal terminal segments, lead to more symmetrical trees as measured by three tree symmetry indicators.Comment: 41 pages, 2 figures, revised structure and text improvement

Insect species described from Big Bend National Park

The list contains 192 insect species, of which 139 are primary types. All have been described from material collected in or near Big Bend National Park, Texas

1st INCF Workshop on Sustainability of Neuroscience Databases

The goal of the workshop was to discuss issues related to the sustainability of neuroscience databases, identify problems and propose solutions, and formulate recommendations to the INCF. The report summarizes the discussions of invited participants from the neuroinformatics community as well as from other disciplines where sustainability issues have already been approached. The recommendations for the INCF involve rating, ranking, and supporting database sustainability

1st INCF Workshop on Global Portal Services for Neuroscience

The goal of this meeting was to map out existing portal services for neuroscience, identify their features and future plans, and outline opportunities for synergistic developments. The workshop discussed alternative formats of future global and integrated portal services

Cases of Lyme Disease Appear to Follow Periodic Cycles Linked to Geography

We are studying the spread of Lyme disease through Wisconsin. It is important because the number of people diagnosed with Lyme Disease in the US is around 300,000, annually (CDC 2017). The CDC has collected data of reported Lyme Disease cases since 2001. When looking at the data we noticed that the trends of cases of Lyme disease followed a cyclical pattern. The cycles varied widely. We hypothesized that environmental and geographical factors could affect the main vector of Lyme Disease, Ixodes scapularis (the black-legged tick). After analyzing Lyme Disease data from the CDC and using a map making software (Paint Maps 2018), we found that geographical distribution had a marked effect on the rate at which counties cycled between up and down trends in infection rates. These findings are important because they give us more insight into possible control methods to keep the black-legged tick, and therefore Lyme Disease, at a manageable level

San Francisco Bay: Preparing for the next level

This report provides new insights on the impacts climate change poses on San Francisco Bay, the opportunities this challenge brings and some potential guidelines on how to move forward, as the Bay Area continues to position itself in leading the way nationally and internationally on climate change adaptation. This report is also a landmark in the cooperation between the Netherlands and California on climate change adaptation. A team of professionals from both sides of the ocean has worked on this projec

A Political Method of Evaluating the Education for All Handicapped Children Act of 1975 and the Several Gaps of Gap Analysis

This project can be seen as a collection of architectural explorations that originate from the concept of misunderstanding. The misunderstanding involves an unconscious transformation that can create something new and unexpected and is therefore an important element both in history and in an individual design process. Five examples of misunderstanding from the history of architecture are described in short texts. From each text a drawing is selected that becomes the starting point for a process where translation between alternating digital and analog representation techniques transform the original object, in multiple steps. For each transformation, a text follows, in which the story is reinterpreted and distorted. The last step in this process is a larger physical object that no longer resembles the original drawing, and which, by its ambiguity begins to live its own life. One theme that emerged during the process has been the relationship between architecture and figures or bodies.Detta projekt kan ses som en samling arkitektoniska betraktelser som tar sin utgångspunkt ur begreppet missförstånd. Missförståndet innebär en omedveten transformation som kan skapa något nytt och oväntat och är därför ett viktigt inslag både i historien och i en individuell designprocess. Fem exempel på missförstånd ur arkitekturhistorien beskrivs i korta texter. Utifrån dessa väljs ett antal ritningar som blir utgångspunkt för en process där översättningen mellan omväxlande digitala och analoga representationstekniker förvandlar det ursprungliga objektet i flera steg. För varje transformation följer en text där berättelsen omtolkas och förvrids. Det sista steget i denna process är ett fysiskt objekt i större skala vars gestalt är svår att härleda till den ursprungliga ritningen och som genom sin tvetydighet börjar leva sitt eget eget liv. Ett tema som utkristalliserat sig under processen har varit relationen mellan arkitektur och figurer eller kroppar

A digital controller using multirate sampling for gain control

Digital controller using multirate sampling for gain contro

Inflatable Aeroponic System

Aeroponics Internationals (AI) innovation is a self-contained, self-supporting, flexible low mass aeroponic crop production unit with integral environmental systems for the control and delivery of a nutrient mist to the roots. This FLEX Aeroponic System model was developed for commercialization as a result of the NASA SBIR Phase I contract for the research and development of a low-mass, Inflatable Aeroponic System (IAS) for producing pesticide-free lettuces, grains, peppers, tomatoes and other vegetables. The innovation addresses the needs of water and nutrient delivery systems technologies for food production in space. The inflatable nature of the innovation makes it lightweight, allowing it to be deflated so it takes up less volume during transportation and storage. It improves upon AI's current aeroponic system design that uses more rigid structures and takes advantage of vertical inclines to increase bio-mass production by over 600%