Biology subjects

Windecker, S.

Publications and source records attributed to Windecker, S..

3 recordsLinked to original sources

bioRxiv2023

Revisiting the role of mean annual precipitation in shaping functional trait distributions at a continental scale

1Mean annual precipitation (MAP) plays an undisputed role in determining the spatial distribution of the vegetative ecosystems on Earth. Nevertheless, the relationship between MAP and plant functional traits remains unclear. Here, we test the relationship between eight key functional traits and MAP. Our analysis reveals a strong, coordinated response of several plant traits including leaf mass per area, leaf nitrogen, the leaf carbon isotope ratio and plant height from resource-conservative to resource-acquisitive values as MAP increased. These results establish an important role for MAP in driving trait selection across space and, therefore, a need for these effects to be included in future theoretical frameworks.

ecology↗

bioRxiv2023

Comparison of shear stress patterns by the established and advanced reconstruction method incorporating side branches to predict plaque progression

BackgroundComplete vessel reconstruction (CVR) with incorporation of side branches is essential for accurate evaluation of wall shear stress (WSS) distribution. However, CVR is time consuming and blood flow simulation is computationally expensive, while there is no evidence that WSS computed by CVR, enables better prediction of disease progression compared to WSS derived from the conventional single vessel reconstruction (SVR). We aim to compare the WSS in models reconstructed using the CVR and SVR methods and examine its ability to predict disease progression. MethodsPatients who had baseline and 13-months follow-up intravascular ultrasound (IVUS) imaging (n=19 vessels), and with neoatherosclerotic lesions (n=13 vessels) on optical coherence tomography (OCT) were included in the present analysis. All the studied vessels had at least one side branch with diameter >1mm. 3-dimensional (3D) CVR and SVR were performed and time averaged (TAWSS) and multidirectional WSS were computed using pulsatile blood flow simulation and the performance of both methods in predicting disease progression in IVUS and OCT models were assessed. ResultsThe incorporation of side branches in 3D geometry resulted in lower TAWSS in the IVUS (0.821 vs 1.698Pa, p<0.001) and OCT-based reconstructions (0.682 vs 1.325Pa, p<0.001) and influenced the multidirectional WSS distribution. In native segments, WSS metrics estimated by the CVR enabled better prediction of the lumen and plaque area and burden at follow-up than SVR and disease progression defined as decrease in lumen area and increase in plaque burden (AUC CVR 0.712 vs SVR 0.554). In stented segments, multidirectional WSS was associated with neointima area in both CVR and SVR methods, but TAWSS was only a predictor of neointima area in the CVR method. ConclusionsThe incorporation of side branches in vessel reconstruction influences WSS distribution and enables more accurate prediction of disease progression in native and stented segments than SVR modelling. HighlightsO_LIComplete vessel reconstruction (CVR) with incorporation of vessel side branches has been proposed for accurate evaluation of wall shear stress (WSS) distribution compared to the traditional single vessel reconstruction (SVR) method; however, there are no studies comparing the performance of the WSS metrics derived by these methods in predicting atherosclerotic evolution. C_LIO_LIIn vessels with large side branches, the incorporation of the side branches in the vessel geometry reconstructed from angiographic and intravascular imaging data resulted in lower time averaged wall shear stress (TAWSS) and influenced the multidirectional WSS estimations compared to the models reconstructed without the side branches. C_LIO_LIThe WSS metrics estimated in the CVR models enabled better prediction of atherosclerotic disease progression at 13-months follow-up on IVUS than the WSS derived by the SVR. C_LIO_LIIn stented vessels, all the WSS metrics in the CVR and the multidirectional WSS in SVR were associated with neointima tissue development; however, both approaches showed limited efficacy in predicting neointima proliferation. C_LI

bioengineering↗

bioRxiv2022

Structured surveys of Australian native possum excreta predict Buruli ulcer occurrence in humans

Buruli ulcer (BU) is a neglected tropical disease caused by infection of subcutaneous tissue with Mycobacterium ulcerans. BU is commonly reported across rural regions of Central and West Africa but has been increasing dramatically in temperate southeast Australia around the major metropolitan city of Melbourne. Previous research has shown that Australian native possums are reservoirs of M. ulcerans and that they shed the bacteria in their fecal material (excreta). Field surveys show that locales where possums harbor M. ulcerans overlap with human cases of BU, raising the possibility of using possum excreta surveys to predict the risk of disease occurrence in humans. We thus established a highly structured 12-month possum excreta surveillance program across an area of 350 km2 in the Mornington Peninsula area 70 km south of Melbourne, Australia. The primary objective of our study was to assess if M. ulcerans surveillance of possum excreta provided useful information for predicting future human BU case locations. Over two sampling campaigns in summer and winter, we collected 2282 possum excreta specimens of which 11% were PCR positive for M. ulcerans-specific DNA. Using the spatial scanning statistical tool SatScan, we observed non-random, co-correlated clustering of both M. ulcerans positive possum excreta and human BU cases. We next trained a statistical model with the Mornington Peninsula excreta survey data to predict the future likelihood of human BU cases occurring in the region. By observing where human BU cases subsequently occurred, we show that the excreta model performance was superior to a null model trained using the previous years human BU case incidence data (AUC 0.66 vs 0.55). We then used data unseen by the excreta-informed model from a new survey of 661 possum excreta specimens in Geelong, a geographically separate BU endemic area to the southwest of Melbourne, to prospectively predict the location of human BU cases in that region. As for the Mornington Peninsula, the excreta-based BU prediction model outperformed the null model (AUC 0.75 vs 0.50) and pinpointed specific locations in Geelong where interventions could be deployed to interrupt disease spread. This study highlights the One Health nature of BU by confirming a quantitative relationship between possum excreta shedding of M. ulcerans and humans developing BU. The excreta survey-informed modeling we have described will be a powerful tool for efficient targeting of public health responses to stop BU.

microbiology↗