Universal fluctuations in growth dynamics of economic systems

The growth of business firms is an example of a system of complex interacting units that resembles complex interacting systems in nature such as earthquakes. Remarkably, work in econophysics has provided evidence that the statistical properties of the growth of business firms follow the same sorts of power laws that characterize physical systems near their critical points. Given how economies change over time, whether these statistical properties are persistent, robust, and universal like those of physical systems remains an open question. Here, we show that the scaling properties of firm growth previously demonstrated for publicly-traded U.S. manufacturing firms from 1974 to 1993 apply to the same sorts of firms from 1993 to 2015, to firms in other broad sectors (such as materials), and to firms in new sectors (such as Internet services). We measure virtually the same scaling exponent for manufacturing for the 1993 to 2015 period as for the 1974 to 1993 period and virtually the same scaling exponent for other sectors as for manufacturing. Furthermore, we show that fluctuations of the growth rate for new industries self-organize into a power law over relatively short time scales.Comment: 15 pages, 7 figure

The nutrition transition and indicators of child malnutrition

We analyze how the nutrition transition affects child malnutrition in developing countries. It is often assumed that the nutrition transition affects child weight but not child growth, which could be one reason why child underweight decreases faster than child stunting. But these effects have hardly been analyzed empirically. Our cross-country panel regressions show that the nutrition transition reduces child underweight, while no consistent effect on child overweight is found. Against common views, our results also suggest that the nutrition transition reduces child stunting. Further research is required to confirm these findings

The evolving role of farm and off-farm jobs in rural Africa

Livelihood sources in rural Africa are diverse and dynamic. Using recent primary data from four African countries — Kenya, Namibia, Tanzania, and Zambia — we consider regions with different conditions related to climate, agroecology, infrastructure, and nature conservation to analyze the role of various income sources for households and individuals. While most rural households are involved in small-scale farming, we challenge the conventional notion that own agricultural activities still constitute the main source of income. Off-farm sources account for 60% of total household income on average. The off-farm income share increases with total income, meaning that the poorest households are the ones most dependent on agriculture. These patterns are similar across all four countries. While the concrete off-farm activities differ by context, most off-farm jobs are self-employed activities in small informal businesses. More lucrative formal employment opportunities are rare and mostly pursued by individuals with post-secondary education and training. Males are more likely to be involved in wage employment than females. Furthermore, individual social networks and access to road and market infrastructure increase the likelihood of off-farm employment. These results emphasize the policy need to acknowledge the important role of rural off-farm jobs and to invest more into generating inclusive non-agricultural employment

Thermoelectric Power Factor of In2O3:Pd Nanocomposite Films.

A nanocomposite exhibiting large thermoelectric powers and capable of operating at temperatures as high as 1100 °C in air was fabricated by embedding palladium nanoparticles into an indium oxide matrix via co-sputtering from metal and ceramic targets. Combinatorial chemistry techniques were used to systematically investigate the effect of palladium content in these nanocomposite films on thermoelectric response. Based on these rapid screening experiments, the thermoelectric properties of the most promising nanocomposites were evaluated as a function of post-deposition heat treatment at high temperatures. An n-type nanocomposite film was developed exhibiting a power factor of 4.5 x 10-4 W/m·K2 at 1000 °C in air

Molecular Mechanisms of Uranium Reduction by Clostridia and its Manipulation

The objective of this grant is to examine and manipulate the molecular mechanisms in Clostridia to make them better agents for uranyl [U(VI)] bioremediation

Development of combinatorial bacteria for metal and radionuclide bioremediation

The grant concerned chromate [Cr(VI)] bioremediation and it was our aim from the outset to construct individual bacterial strains capable of improved bioremediation of multiple pollutants and to identify the enzymes suited to this end. Bacteria with superior capacity to remediate multiple pollutants can be an asset for the cleanup of DOE sites as they contain mixed waste. I describe below the progress made during the period of the current grant, providing appropriate context

Adherence to Mediterranean dietary pattern and the risk of gestational diabetes mellitus:a systematic review and meta-analysis of observational studies

Background and aim: Gestational diabetes mellitus (GDM) is one of the most prevalent disorders occurring during pregnancy, which confers significant risk of short and long-term adverse outcomes in both mothers and offspring. Recently, more attention has been paid to the association of pre-pregnancy and early pregnancy healthy dietary patterns, such as Mediterranean dietary pattern with GDM. However, there is a lack of systematic review and meta-analysis summarizing findings in this regard. Hence, we sought to assess the association of MedDiet and GDM in observational studies by performing a systematic review and meta-analysis. Methods: A comprehensive systematic literature search of observational studies was conducted via PubMed, Scopus, and Google Scholar, up to August 2023. Studies were included in our review if they evaluated the association of MedDiet and GDM, following an observational study design. Results: Ten studies were included in this study. Combining effect sizes, we found that adherence to MedDiet was inversely associated with GDM risk (OR = 0.64; CI: 0.52–0.78); implying that higher adherence to the MedDiet could reduce the risk of GDM by about 36%. Stratification by the geographic area, Mediterranean countries, time of dietary assessment and study design, showed a consistent significant association between MedDiet and GDM. Conclusion: We conclude that adhering to diets resembling MedDiet, before or in early pregnancy, could be associated with lower risks or odds of GDM

Shape-controlled single-crystal growth of InP at low temperatures down to 220 °C.

III-V compound semiconductors are widely used for electronic and optoelectronic applications. However, interfacing III-Vs with other materials has been fundamentally limited by the high growth temperatures and lattice-match requirements of traditional deposition processes. Recently, we developed the templated liquid-phase (TLP) crystal growth method for enabling direct growth of shape-controlled single-crystal III-Vs on amorphous substrates. Although in theory, the lowest temperature for TLP growth is that of the melting point of the group III metal (e.g., 156.6 °C for indium), previous experiments required a minimum growth temperature of 500 °C, thus being incompatible with many application-specific substrates. Here, we demonstrate low-temperature TLP (LT-TLP) growth of single-crystalline InP patterns at substrate temperatures down to 220 °C by first activating the precursor, thus enabling the direct growth of InP even on low thermal budget substrates such as plastics and indium-tin-oxide (ITO)-coated glass. Importantly, the material exhibits high electron mobilities and good optoelectronic properties as demonstrated by the fabrication of high-performance transistors and light-emitting devices. Furthermore, this work may enable integration of III-Vs with silicon complementary metal-oxide-semiconductor (CMOS) processing for monolithic 3D integrated circuits and/or back-end electronics

Farmer-friendly delivery of veterinary services : Experimental insights from the Kenyan dairy sector

Poor health conditions of livestock cause sizeable losses for many farmers in the Global South. Veterinary services, including vaccinations, could help but often fail to reach farmers under typical smallholder conditions. Here, we examine how the provision of a vaccine against East Cost Fever (ECF) – a tick-borne disease affecting cattle in Africa – can be designed to reduce typical adoption barriers. Using data from a choice experiment with dairy farmers in Kenya, we evaluate farmers’ preferences and willingness to pay for various institutional innovations in vaccine delivery, such as a stronger role of dairy cooperatives, new payment modalities with a check-off system, vaccination at farmers’ homestead, and bundling vaccinations with discounts for livestock insurance. Our data reveal that farmers’ awareness of the ECF vaccine is limited and adoption rates are low, largely due to institutional constraints. Results from mixed logit and latent class models suggest that suitable institutional innovations – tailored to farmers’ heterogeneous conditions – could significantly increase adoption. This general finding likely also holds for other veterinary technologies and services in the Global South

Cost of Ending Hunger – Consequences of Complacency, and Financial Needs for SDG2 Achievement

This study follows from an earlier assessment carried out by ZEF and FAO in 2020, which identified policy actions and investments needed to achieve SDG2 by 2030. The 2020 study used a marginal abatement cost curve (MACC) to identify a mix of best least-cost investment options with the highest potential for reduction in hunger and malnutrition over the decade of 2020 to 2030. In light of recent developments in food insecurity and related drivers, such as inflation and changed contexts, this study now recalculates the investment needs and reevaluates priority interventions to achieve the ambitious target of Zero Hunger. Two different analyses are provided: • “Urgency for 2030” – actions with short-term impactful investments: The study presents a short-term focused Marginal Abatement Cost Curve (MACC) analysis, identifying interventions that can be feasibly invested in to achieve significant hunger reduction by 2030, i.e. mostly transfers. • “Realism with urgency” – investing for ending hunger by 2040 without further delay: The need to prioritize interventions with sustained longer-term impacts jointly with the short-term actions are identified, i.e. a MACC analysis that also considers investments requiring more time to take effect beyond 2030. Most of these interventions interact and complement each other. In order to gain an additional perspective, we use the MIRAGRODEP model to simulate the cost consequences of “lost years”