Corn Yield Response to Row Spacing and Plant Population in Iowa

Corn (Zea mays L.) planted in narrow row spacing (\u3c30-inch) with high plant population has become a recent interest in the US Corn Belt to increase grain yield. We evaluated the impact of row spacing and plant population on corn grain yield across 22 site-years in Iowa from 2009 to 2018. Experiments were designed as a split-plot with two row spacings, 20- and 30-inch, as the main-plot and three to four plant populations, ranging from 30,000 to 42,000 plants acre–1, as subplot. Grain yield was affected in 73% of the site-years: 13 site-years by row spacing, six site-years by plant population, and 2 site-years by the interaction of both. Corn in 20-inch rows yielded 5 to 19 bu acre–1 more in 11 site-years and 10 to 14 bu acre–1 less in two site-years compared to 30-inch rows. In both 20- and 30-inch row spacings, corn yield decreased linearly at 0.4 to 1.7 bu acre–1 per thousand increase in plant population in four site-years and responded quadratically with peak yield at around 36,000 plants acre–1 in two site-years. However, corn yield increased linearly at 2.0 to 3.1 bu acre–1 per thousand increase in plant population only when planted in 20-inch row in two site-years. When all 22 site-years were combined, yield was only affected by row spacing. Corn in 20-inch rows produced similar yield under low yielding environments and 8 to 10 bu acre–1 more yield under high yielding environments compared to 30-inch row spacing. Results suggest that farmers should move to 20-inch row spacing at yield levels greater than 235 bu acre–1

Communication between receptors for different ligands on a single cell...

Receptors for the third component of complement (C3) on cultured human monocytes (MO) bind ligand-coated particles but do not initiate phagocytosis. The function of these receptors, however, is altered dramatically after MO attach to surfaces coated with fibronectin (FN) or after MO are exposed to phorbol esters. FN and phorbol esters "activate" C3 receptors such that they promote vigorous phagocytosis. Here we show that activation of C3 receptors requires the continuous presence of FN or phorbol esters and is rapidly reversible when these stimuli are removed. Activation does not change the number or distribution of C3 receptors on the surface of MO. We conclude that the function of C3 receptors is regulated by reversible reactions that are initiated by ligation of a different class of receptors on the surface of the same cell

Heat Transfer Phenomena in Supercritical Water Nuclear Reactors

A supercritical water heat transfer facility has been built at the University of Wisconsin to study heat transfer in ancircular and square annular flow channel. A series of integral heat transfer measurements has been carried out over a wide range of heat flux, mas velocity and bulk water temperatures at a pressure of 25 MPa. The circular annular test section geometry is a 1.07 cm diameter heater rod within a 4.29 diameter flow channel

Does grazing winter cereal rye in Iowa, USA, make it profitable?

Unproven economic returns at the farm level are a major barrier to large-scale adoption of cover crops. The objective of this study was to evaluate the short-run private net returns to producers implementing a cereal rye (Secale cereale L.) cover crop preceding the no-till corn (Zea mays L.) phase of a US Midwest corn–soybean (Glycine max [L.] Merr.) rotation in an integrated crop and cow–calf operation. We used experimental agronomic data from six location-years in Iowa to estimate private net returns to cereal rye across alternative scenarios in a partial budget framework. Net returns in the absence of grazing averaged −$123.74 ha−1 and were negative for 82.2$15.24 ha−1 and were negative for 54.8% of the treatments. Early-broadcast cereal rye produced higher biomass and larger net cost savings in the livestock enterprise than late-drilled cereal rye, but it also resulted in higher corn yield penalties. In the no-grazing scenario, net losses for early-broadcast cereal rye were $165.97 ha−1 larger, on average, than for late-drilled cereal rye. Our findings should raise awareness about the low probability of obtaining positive annual private net returns to cereal rye in Iowa in the absence of sizable targeted financial incentives, and inform the policy discussion on the cost-effectiveness of government-sponsored conservation programs.This article is published as Plastina A, Acharya J, Marcos FM, Parvej MR, Licht MA, Robertson AE. Does grazing winter cereal rye in Iowa, USA, make it profitable? Renewable Agriculture and Food Systems. 2023;38:e45. doi:10.1017/S1742170523000388. © The Author(s), 2023. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited

Severe storm damage and short-term weather stresses on corn: A review

Adverse weather conditions from acute events (e.g., storms causing lodging, flooding, or hail) or short-duration weather patterns (i.e., periods of cold events; extended waterlogged field conditions) can result in yield losses, though management practices may play key roles in aiding with crop recovery or avoidance of these stress events. This review summarizes current knowledge (with emphasis placed on the US Midwest) related to corn response to short-term weather stresses of (i) cold temperature, (ii) excess water, (iii) hail/defoliation damage, and (iv) wind damage. Each section presents summaries of how corn growth and yield are affected, provides context into past events experienced, identifies agronomic or production recommendations to correct or alleviate the stress condition, and proposes areas where future research is needed. This review also highlights challenges associated with controlled simulation work on these stressors, and also identifies key areas to expand future research efforts. In general, yield losses associated with strong storms and short-term weather events often ranged from 5% to 35%, but extreme cases could result in up to 80%–100% yield loss. Much of the literature on these topics was published prior to 1995, though it still forms the basis for modern agronomic guidance, which is problematic given the changes in agriculture in the last 20 years in management practices, available genetics and technologies, and changing environmental conditions. Revisiting these foundational studies and expanding them to examine current and future weather conditions are critical for better informing agronomic recommendations, for devising mitigation strategies, and for determining accurate yield loss expectations following these stresses.This article is published as Lindsey, Alexander J., Osler A. Ortez, Peter R. Thomison, Paul R. Carter, Jeffrey A. Coulter, Greg W. Roth, Daniela R. Carrijo, Daniel J. Quinn, and Mark A. Licht. "Severe storm damage and short‐term weather stresses on corn: A review." Crop Science 64 (2024):1129-1166. https://doi.org/10.1002/csc2.21212. © 2024 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited

Assessing Variation in US Soybean Seed Composition (Protein and Oil)

Soybean [Glycine max (L.) Merr.] seed composition and yield are a function of genetics (G), environment (E), and management (M) practices, but contribution of each factor to seed composition and yield are not well understood. The goal of this synthesis-analysis was to identify the main effects of G, E, and M factors on seed composition (protein and oil concentration) and yield. The entire dataset (13,574 data points) consisted of 21 studies conducted across the United States (US) between 2002 and 2017 with varying treatments and all reporting seed yield and composition. Environment (E), defined as site-year, was the dominant factor accounting for more than 70% of the variation for both seed composition and yield. Of the crop management factors: (i) delayed planting date decreased oil concentration by 0.007 to 0.06% per delayed week (R2∼0.70) and a 0.01 to 0.04 Mg ha-1 decline in seed yield per week, mainly in northern latitudes (40–45 N); (ii) crop rotation (corn-soybean) resulted in an overall positive impact for both seed composition and yield (1.60 Mg ha-1 positive yield difference relative to continuous soybean); and (iii) other management practices such as no-till, seed treatment, foliar nutrient application, and fungicide showed mixed results. Fertilizer N application in lower quantities (10–50 kg N ha-1) increased both oil and protein concentration, but seed yield was improved with rates above 100 kg N ha-1. At southern latitudes (30–35 N), trends of reduction in oil and increases in protein concentrations with later maturity groups (MG, from 3 to 7) was found. Continuing coordinated research is critical to advance our understanding of G × E × M interactions

Internet use by older adults with bipolar disorder: international survey results

Background: The world population is aging and the number of older adults with bipolar disorder is increasing. Digital technologies are viewed as a framework to improve care of older adults with bipolar disorder. This analysis quantifies Internet use by older adults with bipolar disorder as part of a larger survey project about information seeking. Methods: A paper-based survey about information seeking by patients with bipolar disorder was developed and translated into 12 languages. The survey was anonymous and completed between March 2014 and January 2016 by 1222 patients in 17 countries. All patients were diagnosed by a psychiatrist. General estimating equations were used to account for correlated data. Results: Overall, 47% of older adults (age 60 years or older) used the Internet versus 87% of younger adults (less than 60 years). More education and having symptoms that interfered with regular activities increased the odds of using the Internet, while being age 60 years or older decreased the odds. Data from 187 older adults and 1021 younger adults were included in the analysis excluding missing values. Conclusions: Older adults with bipolar disorder use the Internet much less frequently than younger adults. Many older adults do not use the Internet, and technology tools are suitable for some but not all older adults. As more health services are only available online, and more digital tools are developed, there is concern about growing health disparities based on age. Mental health experts should participate in determining the appropriate role for digital tools for older adults with bipolar disorder.We acknowledge support by the Open Access Publication Funds of the SLUB/TU Dresden (Grant No. IN-1502335)

Sprouty Proteins Inhibit Receptor-mediated Activation of Phosphatidylinositol-specific Phospholipase C

PLCγ03B3 binds Spry1 and Spry2. Overexpression of Spry decreased PLCγ03B3 activity and IP3 and DAG production, whereas Spry-deficient cells yielded more IP3. Spry overexpression inhibited T-cell receptor signaling and Spry1 null T-cells hyperproliferated with TCR ligation. Through action of PLCγ03B3, Spry may influence signaling through multiple receptors

International multi-site survey on the use of online support groups in bipolar disorder

Background: Peer support is an established component of recovery from bipolar disorder, and online support groups may offer opportunities to expand the use of peer support at the patient’s convenience. Prior research in bipolar disorder has reported value from online support groups. Aims: To understand the use of online support groups by patients with bipolar disorder as part of a larger project about information seeking. Methods: The results are based on a one-time, paper-based anonymous survey about information seeking by patients with bipolar disorder, which was translated into 12 languages. The survey was completed between March 2014 and January 2016 and included questions on the use of online support groups. All patients were diagnosed by a psychiatrist. Analysis included descriptive statistics and general estimating equations to account for correlated data. Results and conclusions: The survey was completed by 1222 patients in 17 countries. The patients used the Internet at a percentage similar to the general public. Of the Internet users who looked online for information about bipolar disorder, only 21.0% read or participated in support groups, chats, or forums for bipolar disorder (12.8% of the total sample). Given the benefits reported in prior research, clarification of the role of online support groups in bipolar disorder is needed. With only a minority of patients using online support groups, there are analytical challenges for future studies

Bioavailability of Macro and Micronutrients Across Global Topsoils: Main Drivers and Global Change Impacts

Understanding the chemical composition of our planet\u27s crust was one of the biggest questions of the 20th century. More than 100 years later, we are still far from understanding the global patterns in the bioavailability and spatial coupling of elements in topsoils worldwide, despite their importance for the productivity and functioning of terrestrial ecosystems. Here, we measured the bioavailability and coupling of thirteen macro- and micronutrients and phytotoxic elements in topsoils (3–8 cm) from a range of terrestrial ecosystems across all continents (∼10,000 observations) and in response to global change manipulations (∼5,000 observations). For this, we incubated between 1 and 4 pairs of anionic and cationic exchange membranes per site for a mean period of 53 days. The most bioavailable elements (Ca, Mg, and K) were also amongst the most abundant in the crust. Patterns of bioavailability were biome-dependent and controlled by soil properties such as pH, organic matter content and texture, plant cover, and climate. However, global change simulations resulted in important alterations in the bioavailability of elements. Elements were highly coupled, and coupling was predictable by the atomic properties of elements, particularly mass, mass to charge ratio, and second ionization energy. Deviations from the predictable coupling-atomic mass relationship were attributed to global change and agriculture. Our work illustrates the tight links between the bioavailability and coupling of topsoil elements and environmental context, human activities, and atomic properties of elements, thus deeply enhancing our integrated understanding of the biogeochemical connections that underlie the productivity and functioning of terrestrial ecosystems in a changing world