Strip intercropping systems

Economic, environmental, and biological concerns prompt the search for alternative, sustainable, agricultural production systems. Farmers need cropping systems that reduce negative impacts on the environment while maintaining or even improving farm profitabilit

The Bone Morphogenetic Protein 2 Analogue L51P Enhances Spinal Fusion in Combination with BMP2 in an In Vivo Rat Tail Model

INTRODUCTION Non-union and pseudoarthrosis remain major complications after spinal fusion surgery, resulting in unsatisfactory outcomes and high socio-economic costs [1,2]. Several biomaterials and osteobiologics have improved spinal fusion, including bone morphogenetic protein (BMP) 2. However, its necessary high-dose application often leads to adverse effects. L51P, a BMP-2 analogue and inhibitor of BMP antagonists, has been shown to augment BMP-induced bone formation and lower the required doses. The current study, therefore, aimed to demonstrate the effects of L51P and BMP-2 on spinal fusion in vivo. METHODS 46 elderly Wistar rats (~12 months, 52% female, 423±78g) underwent a two-step spinal fusion surgery [3,4]. Firstly, a custom external fixator was applied in the proximal tail. Secondly, discectomy and disc replacement with a β tri-calcium-phosphate (β-TCP) carrier were conducted. Carriers were loaded with the study compounds based on random and blinded allocation into seven groups: g Digital X-rays were performed on day zero, at six weeks, and twelve weeks postoperatively. After twelve weeks, high-resolution µCT scans and histology were obtained. RESULTS At twelve weeks, 10 µg BMP-2, 1 µg BMP-2 + 5 µg L51P and 1 µg BMP-2 + 10 µg L51P showed significantly higher fusion rates compared to the PBS control in X-ray analysis. µCT analysis showed significantly higher fusion rates for all groups than the control group. 1 µg BMP-2 + 1 µg L51P demonstrated significantly higher fusion rates than 1 µg BMP2 alone and equivalent ossification compared to 10 µg BMP-2; higher doses of L51P did not lead to a better fusion outcome. Histological analysis confirmed the radiographical results. Figure 1 provides representative images of the seven experimental groups for each investigated read-outs, i.e., 2D X-rays, µCT and histology

Local Difference Measures between Complex Networks for Dynamical System Model Evaluation

Acknowledgments We thank Reik V. Donner for inspiring suggestions that initialized the work presented herein. Jan H. Feldhoff is credited for providing us with the STARS simulation data and for his contributions to fruitful discussions. Comments by the anonymous reviewers are gratefully acknowledged as they led to substantial improvements of the manuscript.Peer reviewedPublisher PD

A comparison of polarized and non-polarized human endometrial monolayer culture systems on murine embryo development

BACKGROUND: Co-culture of embryos with various somatic cells has been suggested as a promising approach to improve embryo development. Despite numerous reports regarding the beneficial effects of epithelial cells from the female genital tract on embryo development in a co-culture system, little is known about the effect of these cells when being cultured under a polarized condition on embryo growth. Our study evaluated the effects of in vitro polarized cells on pre-embryo development. METHODS: Human endometrial tissue was obtained from uterine specimens excised at total hysterectomy performed for benign indications. Epithelial cells were promptly isolated and cultured either on extra-cellular matrix gel (ECM-Gel) coated millipore filter inserts (polarized) or plastic surfaces (non-polarized). The epithelial nature of the cells cultured on plastic was confirmed through immunohistochemistry, and polarization of cells cultured on ECM-Gel was evaluated by transmission electron microscopy (TEM). One or two-cell stage embryos of a superovulated NMRI mouse were then flushed and placed in culture with either polarized or non-polarized cells and medium alone. Development rates were determined for all embryos daily and statistically compared. At the end of the cultivation period, trophectoderm (TE) and inner cell mass (ICM) of expanded blastocysts from each group were examined microscopically. RESULTS: Endometrial epithelial cells cultured on ECM-Gel had a highly polarized columnar shape as opposed to the flattened shape of the cells cultured on a plastic surface. The two-cell embryos cultured on a polarized monolayer had a higher developmental rate than those from the non-polarized cells. There was no statistically significant difference; still, the blastocysts from the polarized monolayer, in comparison with the non-polarized group, had a significantly higher mean cell number. The development of one-cell embryos in the polarized and non-polarized groups showed no statistically significant difference. CONCLUSION: Polarized cells could improve in vitro embryo development from the two-cell stage more in terms of quality (increasing blastocyst cellularity) than in terms of developmental rate

Link-Prediction to Tackle the Boundary Specification Problem in Social Network Surveys

Diffusion processes in social networks often cause the emergence of global phenomena from individual behavior within a society. The study of those global phenomena and the simulation of those diffusion processes frequently require a good model of the global network. However, survey data and data from online sources are often restricted to single social groups or features, such as age groups, single schools, companies, or interest groups. Hence, a modeling approach is required that extrapolates the locally restricted data to a global network model. We tackle this Missing Data Problem using Link-Prediction techniques from social network research, network generation techniques from the area of Social Simulation, as well as a combination of both. We found that techniques employing less information may be more adequate to solve this problem, especially when data granularity is an issue. We validated the network models created with our techniques on a number of real-world networks, investigating degree distributions as well as the likelihood of links given the geographical distance between two nodes

The Bone Morphogenetic Protein 2 Analogue L51P Enhances Spinal Fusion in Combination with BMP2 in an In Vivo Rat Tail Model.

Bone morphogenic protein 2 (BMP2) is known to induce osteogenesis and is applied clinically to enhance spinal fusion despite adverse effects. BMP2 needs to be used in high doses to be effective due to the presence of BMP2 inhibitors. L51P is a BMP2 analogue that acts by inhibition of BMP2 inhibitors. Here, we hypothesized that mixtures of BMP2 and L51P could achieve better spinal fusion outcomes regarding ossification. To test whether mixtures of both cytokines are sufficient to improve ossification, 45 elderly Wistar rats (of which 21 were males) were assigned to seven experimental groups, all which received spinal fusion surgery, including discectomy at the caudal 4-5 level using an external fixator and a porous β-tricalcium phosphate (βTCP) carrier. These βTCP carriers were coated with varying concentrations of BMP2 and L51P. X-rays were taken immediately after surgery and again six and twelve weeks post-operatively. Histological sections and µCT were analyzed after twelve weeks. Spinal fusion was assessed using X-ray, µCT and histology according to the Bridwell scale by voxel-based quantification and a semi-quantitative histological score, respectively. The results were congruent across modalities and revealed high ossification for high-dose BMP2 (10 µg), while PBS induced no ossification. Low-dose BMP2 (1 µg) or 10 µg L51P alone did not induce relevant bone formation. However, all combinations of low-dose BMP2 with L51P (1 µg + 1/5/10 µg) were able to induce similar ossificationas high-dose BMP2. These results are of high clinical relevance, as they indicate L51P is sufficient to increase the efficacy of BMP2 and thus lower the required dose for spinal fusion. STATEMENT OF SIGNIFICANCE: Spinal fusion surgery is frequently applied to treat spinal pathologies. Bone Morphogenic Protein-2 (BMP2) has been approved by the U .S. Food and Drug Administration (FDA-) and by the "Conformité Européenne" (CE)-label. However, its application is expensive and high concentrations cause side-effects. This research targets the improvement of the efficacy of BMP2 in spinal fusion surgery