Extracting Tree-structures in CT data by Tracking Multiple Statistically Ranked Hypotheses

In this work, we adapt a method based on multiple hypothesis tracking (MHT) that has been shown to give state-of-the-art vessel segmentation results in interactive settings, for the purpose of extracting trees. Regularly spaced tubular templates are fit to image data forming local hypotheses. These local hypotheses are used to construct the MHT tree, which is then traversed to make segmentation decisions. However, some critical parameters in this method are scale-dependent and have an adverse effect when tracking structures of varying dimensions. We propose to use statistical ranking of local hypotheses in constructing the MHT tree, which yields a probabilistic interpretation of scores across scales and helps alleviate the scale-dependence of MHT parameters. This enables our method to track trees starting from a single seed point. Our method is evaluated on chest CT data to extract airway trees and coronary arteries. In both cases, we show that our method performs significantly better than the original MHT method.Comment: Accepted for publication at the International Journal of Medical Physics and Practic

Field efficacy of new compounds to replace copper for scab control in organic apple production

Efficacy of compounds was investigated in field experiments in Denmark and the Netherlands according to EPPO guidelines. Some Yucca extracts and potassium bicarbonate had an efficacy similar to sulphur on leaves. Addition of sulphur to Yucca 1 and to potassium bicarbonate increased the level of efficacy to that of copper. This confirms results from earlier years. Although a dose increase resulted in better efficacy, this was more prominent for Yucca1 than for potassium bicarbonate

Role of physiological ClC-1 Cl- ion channel regulation for the excitability and function of working skeletal muscle.

Electrical membrane properties of skeletal muscle fibers have been thoroughly studied over the last five to six decades. This has shown that muscle fibers from a wide range of species, including fish, amphibians, reptiles, birds, and mammals, are all characterized by high resting membrane permeability for Cl(-) ions. Thus, in resting human muscle, ClC-1 Cl(-) ion channels account for ∼80% of the membrane conductance, and because active Cl(-) transport is limited in muscle fibers, the equilibrium potential for Cl(-) lies close to the resting membrane potential. These conditions-high membrane conductance and passive distribution-enable ClC-1 to conduct membrane current that inhibits muscle excitability. This depressing effect of ClC-1 current on muscle excitability has mostly been associated with skeletal muscle hyperexcitability in myotonia congenita, which arises from loss-of-function mutations in the CLCN1 gene. However, given that ClC-1 must be drastically inhibited (∼80%) before myotonia develops, more recent studies have explored whether acute and more subtle ClC-1 regulation contributes to controlling the excitability of working muscle. Methods were developed to measure ClC-1 function with subsecond temporal resolution in action potential firing muscle fibers. These and other techniques have revealed that ClC-1 function is controlled by multiple cellular signals during muscle activity. Thus, onset of muscle activity triggers ClC-1 inhibition via protein kinase C, intracellular acidosis, and lactate ions. This inhibition is important for preserving excitability of working muscle in the face of activity-induced elevation of extracellular K(+) and accumulating inactivation of voltage-gated sodium channels. Furthermore, during prolonged activity, a marked ClC-1 activation can develop that compromises muscle excitability. Data from ClC-1 expression systems suggest that this ClC-1 activation may arise from loss of regulation by adenosine nucleotides and/or oxidation. The present review summarizes the current knowledge of the physiological factors that control ClC-1 function in active muscle

Soybean seeding rates: The balance between cost and yield

Since 2003, the soybean extension program has conducted more than two dozen experiments across the state to evaluate seeding rate recommendations. Extension researchers have used seeding rates of 75,000, 125,000, 175,000, and 225,000 seeds per acre and determined how these seeding rates performed both at early and late planting dates and in 15 and 30 row spacing. This research was funded by the checkoff and the Iowa Soybean Association, and new seeding rate recommendations have been released based on the information gathered from these experiments

Hail injury to corn and soybean

Last weekend was certainly an eventful week in terms of weather across the state. Unfortunately, in several of those heavy rainfall areas hail also occurred, adding a whole new dimension to crop injuries. Along with the flooded fields that will reduce plant stands, the damage caused to the plant by hail will also have to be considered when making replant decisions. Corn and soybean differ in their ability to tolerate hail damage and to compensate for reduced stands. For both crops, however, it is essential to make good estimations of plant health and accurate stand counts in order to determine the need for replanting

How many seeds does it really take to get 100,000 plants per acre at harvest?

In last week\u27s article, Soybean seeding rates: The balance between cost and yield, the case was made that 100,000 plants per acre at harvest was sufficient to reach both full yield potential and economic return. An important question that is often asked is, how many seeds need to be planted to attain this final stand at harvest? In a perfect world, the relationship would be 1:1, indicating that every seed planted would correspond to a plant at harvest. We all know this is not the case. Since 2003, Iowa State University Extension researchers have conducted more than two dozen experiments with the checkoff and the Iowa Soybean Association at multiple locations across Iowa

Corn and Soybean Rotation Study

Crop rotation and tillage systems have an impact on both production cost and yield. The use of an alternating corn and soybean rotation rather than continuous corn or soybean typically results in higher net return and lower variability since the economics of crop rotation are largely tied to the effect of introducing a break crop. However, limited research exits in Iowa with just corn and soybean in the rotations. The objective of this study was to determine the long-term effect on yield and profitability with continuous corn or soybean vs. rotated corn and soybean using different tillage systems. The study is conducted at two locations—Ames and the ISU Northwest Research Farm, Sutherland, IA