Nonlinear Advantage: Trained Networks Might Not Be As Complex as You Think

We perform an empirical study of the behaviour of deep networks when fully linearizing some of its feature channels through a sparsity prior on the overall number of nonlinear units in the network. In experiments on image classification and machine translation tasks, we investigate how much we can simplify the network function towards linearity before performance collapses. First, we observe a significant performance gap when reducing nonlinearity in the network function early on as opposed to late in training, in-line with recent observations on the time-evolution of the data-dependent NTK. Second, we find that after training, we are able to linearize a significant number of nonlinear units while maintaining a high performance, indicating that much of a network's expressivity remains unused but helps gradient descent in early stages of training. To characterize the depth of the resulting partially linearized network, we introduce a measure called average path length, representing the average number of active nonlinearities encountered along a path in the network graph. Under sparsity pressure, we find that the remaining nonlinear units organize into distinct structures, forming core-networks of near constant effective depth and width, which in turn depend on task difficulty

Inter- and transdisciplinary scenario construction to explore future land-use options in southern Amazonia

Our aim with this paper is to present a novel approach for developing story lines and scenarios by combining qualitative knowledge and quantitative data from different disciplines and discussing the results with relevant decision makers. This research strategy offers a solid foundation for perspectives into the future. The “laboratory” is the Brazilian Amazon, one of the hotspots of land-use change where local and global interests both collide and converge: local livelihoods are affected by regional and global climate change and by the loss of biodiversity caused by local and global economic interests in agro-industrial land use; such use contributes, in turn, to climate change. After decades of diverse policy interventions the question arises: What can we learn from past trajectories for a more sustainable development in the future? To answer this question, we combined qualitative story lines for the region, reviewed by local experts, with quantitative land-use scenarios, to study their regional and local manifestations in space. These results were then discussed again with local and national experts. Our findings suggest that in- depth knowledge of the diverging perspectives at a very local level is a fundamental prerequisite for downscaling global scenarios and upscaling local approaches to sustainable land-use management and thus, to producing communicable and applicable results

Can agricultural intensification help to conserve biodiversity? A scenario study for the African continent

Globally, the production of food, feed, bioenergy, and biomaterials has increased considerably during the past decades. This was achieved by the expansion of agricultural land and the intensification of agricultural management. Due to the conversion of natural ecosystems and the increasing use of pesticides and fertilizers, these processes are recognized as important causes of biodiversity loss. This study focuses on the African continent and analyses the potentials to achieve a stable food provision for a growing population, and at the same time, reduce further losses of biodiversity. These targets are important elements of the UN Agenda 2030. Using the spatially explicit land-use model LandSHIFT, we assessed the effectiveness of different land-sparing and land-sharing strategies to achieve these targets until the year 2030. The simulation results indicate that under the assumptions tested, the land sparing approach yields the most desirable results both, on the continental and the regional level. However, the land sharing/sparing framework in general, and the research presented here only analyse the effect of two factors of many (food production and biodiversity conservation). Hence, this study should not be understood to provide specific management recommendations. Further studies, from the regional to the local level, are required that apply a systems approach to understand and explain the multiple dimensions of sustainable food production on the African continent.Ye

Sepsis related mortality of extremely low gestational age newborns after the introduction of colonization screening for multi-drug resistant organisms

Background: In 2013 German infection surveillance guidelines recommended weekly colonization screening for multidrug-resistant (MDRO) or highly epidemic organisms for neonatal intensive care units (NICUs) and extended hygiene measures based on screening results. It remains a matter of debate whether screening is worth the effort. We therefore aimed to evaluate sepsis related outcomes before and after the guideline update. Methods: The German Neonatal Network (GNN) is a prospective cohort study including data from extremely preterm infants between 22 + 0 and 28 + 6 gestational weeks born in 62 German level III NICUs. Results: Infants treated after guideline update (n = 8.903) had a lower mortality (12.5% vs. 13.8%, p = 0.036), reduced rates for clinical sepsis (31.4 vs. 42.8%, p < 0.001) and culture-proven sepsis (14.4% vs. 16.5%, p = 0.003) as compared to infants treated before update (n = 3.920). In a multivariate logistic regression analysis, nine pathogens of cultureproven sepsis were associated with sepsis-related death, e.g. Pseudomonas aeruginosa [OR 59 (19–180), p < 0.001)]. However, the guideline update had no significant effect on pathogen-specific case fatality, total sepsis-related mortality and culture-proven sepsis rates with MDRO. While the exposure of GNN infants to cefotaxime declined over time (31.1 vs. 40.1%, p < 0.001), the treatment rate with meropenem was increased (31.6 vs. 26.3%, p < 0.001). Conclusions: The introduction of weekly screening and extended hygiene measures is associated with reduced sepsis rates, but has no effects on sepsis-related mortality and sepsis with screening-relevant pathogens. The high exposure rate to meropenem should be a target of antibiotic stewardship programs

Lactobacillus Acidophilus/Bifidobacterium Infantis Probiotics Are Beneficial to Extremely Low Gestational Age Infants Fed Human Milk

To evaluate the nutrition-related effects of prophylactic Lactobacillus acidophilus/ Bifidobacterium infantis probiotics on the outcomes of preterm infants <29 weeks of gestation that receive human milk and/or formula nutrition. We hypothesize that human-milk-fed infants benefit from probiotics in terms of sepsis prevention and growth. Methods: We performed an observational study of the German Neonatal Network (GNN) over a period of six years, between 1 January, 2013 and 31 December, 2018. Prophylactic probiotic use of L. acidophilus/B. infantis was evaluated in preterm infants <29 weeks of gestation (n = 7516) in subgroups stratified to feeding type: (I) Exclusively human milk (HM) of own mother and/or donors (HM group, n = 1568), (II) HM of own mother and/or donor and formula (Mix group, n = 5221), and (III) exclusive exposure to formula (F group, n = 727). The effect of probiotics on general outcomes and growth was tested in univariate models and adjusted in linear/logistic regression models. Results: 5954 (76.5%) infants received L. acidophilus/B. infantisprophylactically for the prevention of necrotizing enterocolitis (NEC). Probiotic use was associated with improved growth measures in the HM group (e.g., weight gain velocity in g/day: effect size B = 0.224; 95% CI: 2.82–4.35; p < 0.001) but not in the F group (effect size B = −0.06; 95% CI: −3.05–0.28; p = 0.103). The HM group had the lowest incidence of clinical sepsis (34.0%) as compared to the Mix group (35.5%) and the F group (40.0%). Only in the Mix group, probiotic supplementation proved to be protective against clinical sepsis (OR 0.69; 95% CI: 0.59–0.79; p < 0.001). Conclusion: Our observational data indicate that the exposure to L. acidophilus/B. infantis probiotics may promote growth in exclusively HM-fed infants as compared to formula-fed infants. To exert a sepsis-preventive effect, probiotics seem to require human milk

Convalescent plasma treatment for SARS-CoV-2 infected high-risk patients: a matched pair analysis to the LEOSS cohort

Establishing the optimal treatment for COVID-19 patients remains challenging. Specifically, immunocompromised and pre-diseased patients are at high risk for severe disease course and face limited therapeutic options. Convalescent plasma (CP) has been considered as therapeutic approach, but reliable data are lacking, especially for high-risk patients. We performed a retrospective analysis of 55 hospitalized COVID-19 patients from University Hospital Duesseldorf (UKD) at high risk for disease progression, in a substantial proportion due to immunosuppression from cancer, solid organ transplantation, autoimmune disease, dialysis. A matched-pairs analysis (1:4) was performed with 220 patients from the Lean European Open Survey on SARS-CoV-2-infected Patients (LEOSS) who were treated or not treated with CP. Both cohorts had high mortality (UKD 41.8%, LEOSS 34.1%). A matched-pairs analysis showed no significant effect on mortality. CP administration before the formation of pulmonary infiltrates showed the lowest mortality in both cohorts (10%), whereas mortality in the complicated phase was 27.8%. CP administration during the critical phase revealed the highest mortality: UKD 60.9%, LEOSS 48.3%. In our cohort of COVID-19 patients with severe comorbidities CP did not significantly reduce mortality in a retrospective matched-pairs analysis. However, our data supports the concept that a reduction in mortality is achievable by early CP administration

Covid-19 triage in the emergency department 2.0: how analytics and AI transform a human-made algorithm for the prediction of clinical pathways

The Covid-19 pandemic has pushed many hospitals to their capacity limits. Therefore, a triage of patients has been discussed controversially primarily through an ethical perspective. The term triage contains many aspects such as urgency of treatment, severity of the disease and pre-existing conditions, access to critical care, or the classification of patients regarding subsequent clinical pathways starting from the emergency department. The determination of the pathways is important not only for patient care, but also for capacity planning in hospitals. We examine the performance of a human-made triage algorithm for clinical pathways which is considered a guideline for emergency departments in Germany based on a large multicenter dataset with over 4,000 European Covid-19 patients from the LEOSS registry. We find an accuracy of 28 percent and approximately 15 percent sensitivity for the ward class. The results serve as a benchmark for our extensions including an additional category of palliative care as a new label, analytics, AI, XAI, and interactive techniques. We find significant potential of analytics and AI in Covid-19 triage regarding accuracy, sensitivity, and other performance metrics whilst our interactive human-AI algorithm shows superior performance with approximately 73 percent accuracy and up to 76 percent sensitivity. The results are independent of the data preparation process regarding the imputation of missing values or grouping of comorbidities. In addition, we find that the consideration of an additional label palliative care does not improve the results

Rethinking Land in the Anthropocene: from Separation to Integration

Nur wenn sich unser Umgang mit Land grundlegend ändert, können die Klimaschutzziele erreicht, der dramatische Verlust der biologischen Vielfalt abgewendet und das globale Ernährungssystem nachhaltig gestaltet werden. Der WBGU schlägt fünf exemplarische Mehrgewinnstrategien vor, um Konkurrenzen zwischen Nutzungsansprüchen zu überwinden. Diese sollten durch fünf Governance-Strategien vorangetrieben werden, darunter insbesondere die Setzung geeigneter Rahmenbedingungen, eine Neuorientierung der EUPolitik und die Errichtung von Gemeinschaften gleichgesinnter Staaten.Only if there is a fundamental change in the way we manage land can we reach the targets of climate-change mitigation, avert the dramatic loss of biodiversity and make the global food system sustainable. The WBGU proposes five multiple-benefit strategies illustrating ways of overcoming competition between rival claims to the use of land. These should be promoted by five governance strategies, especially by setting suitable framework conditions, reorienting EU policy and establishing alliances of like-minded states

Identification of regulatory variants associated with genetic susceptibility to meningococcal disease.

Non-coding genetic variants play an important role in driving susceptibility to complex diseases but their characterization remains challenging. Here, we employed a novel approach to interrogate the genetic risk of such polymorphisms in a more systematic way by targeting specific regulatory regions relevant for the phenotype studied. We applied this method to meningococcal disease susceptibility, using the DNA binding pattern of RELA - a NF-kB subunit, master regulator of the response to infection - under bacterial stimuli in nasopharyngeal epithelial cells. We designed a custom panel to cover these RELA binding sites and used it for targeted sequencing in cases and controls. Variant calling and association analysis were performed followed by validation of candidate polymorphisms by genotyping in three independent cohorts. We identified two new polymorphisms, rs4823231 and rs11913168, showing signs of association with meningococcal disease susceptibility. In addition, using our genomic data as well as publicly available resources, we found evidences for these SNPs to have potential regulatory effects on ATXN10 and LIF genes respectively. The variants and related candidate genes are relevant for infectious diseases and may have important contribution for meningococcal disease pathology. Finally, we described a novel genetic association approach that could be applied to other phenotypes