HoloPointer: a virtual augmented reality pointer for laparoscopic surgery training.

Purpose: In laparoscopic surgery training, experts guide novice physicians to desired instrument positions or indicate relevant areas of interest. These instructions are usually given via verbal communication or using physical pointing devices. To facilitate a sterile work flow and to improve training, new guiding methods are needed.

Assessment of pesticide inputs into surface waters by agricultural and urban sources - A case study in the Querne/Weida catchment, central Germany.

Pesticide inputs into surface waters may cause harmful effects on aquatic life communities and substantially contribute to environmental pollution. The present study aimed at evaluating the input pathways in the Querne/Weida catchment (central Germany) to efficiently target mitigation measures of pesticide losses. Relevant pesticide substances were measured in surface waters in agricultural and urban surroundings and in soil samples within the catchment area.

Estimation of regional soil organic carbon stocks merging classified land-use information with detailed soil data.

The Kulunda Steppe in southwestern Siberia is one of the most intensely used agricultural landscapes in the world. Today it is characterized by depletive soil management practices and intensities that are unadapted to the local site conditions. Severe soil degradation and a loss of soil organic carbon (SOC) occurs at agriculturally used areas.

Evaluation of regression methodology with low-frequency water quality sampling to estimate constituent loads for ephemeral watersheds in Texas.

Water quality regulation and litigation have elevated the awareness and need for quantifying water quality and source contributions in watersheds across the USA. In the present study, the regression method, which is typically applied to large (perennial) rivers, was evaluated in its ability to estimate constituent loads (NO(3)-N, total N, PO(4)-P, total P, sediment) on three small (ephemeral) watersheds with different land uses in Texas. Specifically, regression methodology was applied with daily flow data collected with bubbler stage recorders in hydraulic structures and with water quality data collected with four low-frequency sampling strategies: random, rise and fall, peak, and single stage.

A navigation system for minimally invasive CT-guided interventions.

The purpose of our project was to develop a novel navigation system for interventional radiology. Fields of application are minimally invasive percutaneous interventions performed under local anaesthesia. In order to reduce unintentional patient movements we used a patient vacuum immobilization device.