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Tuning Frequency Bias in Neural Network Training with Nonuniform Data
(2022)arXivSmall generalization errors of over-parameterized neural networks (NNs) can be partially explained by the frequency biasing phenomenon, where gradient-based algorithms minimize the low-frequency misfit before reducing the high-frequency residuals. Using the Neural Tangent Kernel (NTK), one can provide a theoretically rigorous analysis for training where data are drawn from constant or piecewise-constant probability densities. Since most ...Working Paper -
Local inequality and crime: New evidence from South Africa
(2022)Passauer DiskussionspapiereThe relationship between inequality and crime has been of long-standing interest to social scientists of various disciplines. While theorical work from both economics and sociology postulates a positive link between the two, the empirical evidence is rather inconclusive and typically focuses on higher-income countries. In this study, I investigate the relationship between socio-economic inequalities of various dimensions and both violent ...Working Paper -
Phage Paride hijacks bacterial stress responses to kill dormant, antibiotic-tolerant cells
(2022)bioRxivBacteriophages are fierce viral predators with no regard for pathogenicity or antibiotic resistance of their bacterial hosts1,2. Despite early recognition of their therapeutic potential and the current escalation of bacterial multidrug resistance, phages have so far failed to become a regular treatment option in clinical practice3-5. One reason is the occasional discrepancy between poor performance of selected phages in vivo despite high ...Working Paper -
The fertility transition in Sub-Saharan Africa: The role of structural change
(2022)Passauer DiskussionspapiereDespite relatively sustained economic growth in at least parts of Sub-Saharan Africa over the past twenty years, the fertility transition has not much advanced in most countries in that region. We explore whether the lack of structural change can explain this slow transition. For this end, we analyze the determinants of fertility transitions across the developing world using a novel regional level panel dataset created by matching Demographic ...Working Paper -
Optimal index insurance and basis risk decomposition: an application to Kenya
(2021)arXivIndex insurance is a promising tool to reduce the risk faced by farmers, but high basis risk, which arises from imperfect correlation between the index and individual farm yields, has limited its adoption to date. Basis risk arises from two fundamental sources: the intrinsic heterogeneity within an insurance zone (zonal risk), and the lack of predictive accuracy of the index (design risk). Whereas previous work has focused almost exclusively ...Working Paper -
A scalable and continuous access to pure cyclic polymers enabled by quarantined heterogeneous catalysts
(2021)ChemRxivCyclic polymers are topologically interesting and envisioned as a lubricant material. However, scalable synthesis of pure cyclic polymers remains elusive. The most straightforward way is to recycle a used catalyst for the synthesis of cyclic polymers. Unfortunately, it is demanding because of the catalysts vulnerability and inseparability from polymers, which depreciates the practicality of the process. Here, we develop a continuous process ...Working Paper -
Digital control of c-di-GMP in E. coli balances population-wide developmental transitions and phage sensitivity
(2021)bioRxivNucleotide-based signaling molecules (NSMs) are widespread in bacteria and eukaryotes, where they control important physiological and behavioral processes. In bacteria, NSM-based regulatory networks are highly complex, entailing large numbers of enzymes involved in the synthesis and degradation of active signaling molecules. How the converging input from multiple enzymes is transformed into robust and unambiguous cellular responses has ...Working Paper -
Long-term incubation of lake water enables genomic sampling of consortia involving Planctomycetes and Candidate Phyla Radiation bacteria
(2021)bioRxivMicrobial communities in lakes can profoundly impact biogeochemical processes through their individual activities and collective interactions. However, the complexity of these communities poses challenges, particularly for studying rare members. Laboratory enrichments can select for subsystems of interacting organisms and enable genome recovery for enriched populations. Here, a reactor inoculated with water from Lake Fargette, France, and ...Working Paper -
The Chloroflexi supergroup is metabolically diverse and representatives have novel genes for non-photosynthesis based CO2 fixation
(2021)bioRxivThe Chloroflexi superphylum have been investigated primarily from the perspective of reductive dehalogenation of toxic compounds, anaerobic photosynthesis and wastewater treatment, but remain relatively little studied compared to their close relatives within the larger Terrabacteria group, including Cyanobacteria, Actinobacteria, and Firmicutes. Here, we conducted a detailed phylogenetic analysis of the phylum Chloroflexota, the ...Working Paper -
Borgs are giant extrachromosomal elements with the potential to augment methane oxidation
(2021)bioRxivAnaerobic methane oxidation exerts a key control on greenhouse gas emissions 1, yet factors that modulate the activity of microorganisms performing this function remain little explored. In studying groundwater, sediments, and wetland soil where methane production and oxidation occur, we discovered extraordinarily large, diverse DNA sequences that primarily encode hypothetical proteins. Four curated, complete genomes are linear, up to ~1 ...Working Paper