Environmental Regulation of Hog Feeding Operations

THE US livestock industry has experienced drastic structural changes over the last two decades. The industry has shifted towards greater specialization across production phases, increased reliance on off-farm inputs such as feed, and increased use of production contracts (McBride and Key 2013). One trend that is particularly relevant to Iowa policymakers, farmers, and rural Iowans is the increased prevalence, size, and regional intensity of large, enclosed hog feeding operations. Where many of the largest hog-producing states have seen modest increases or even declines in total hog inventories over time, Iowa has seen a steady increase in inventories since 1982 (Figure 1a). Within Iowa, production concentrates in north-central and northwestern counties (Figure 1b)

Regulation of the Cdc14-like Phosphatase CLP1 in \u3cem\u3e Schizosaccharomyces pombe\u3c/em\u3e and Identification of SID2 Kinase Substrates: A Dissertation

Coordination of mitosis and cytokinesis is crucial to generate healthy daughter cells with equal amounts of genetic and cytoplasmic materials. In the fission yeast Schizosaccharomyces pombe, an evolutionarily conserved Cdc14-like phosphatase (Clp1) functions to couple mitosis and cytokinesis by antagonizing CDK activity. The activity of Clp1 is thought to be regulated in part by its subcellular localization. It is sequestered in the nucleolus and the spindle pole body (SPB) during interphase. Upon mitotic entry, it is released into the cytoplasm and localized to the kinetochores, the actomyosin ring, and the mitotic spindle to carry out distinct functions. It is not clear how Clp1 is released from the nucleolus, however, once released, a conserved signaling pathway termed Septation Initiation Network (SIN) functions to retain Clp1 in the cytoplasm until completion of cytokinesis. The SIN and Clp1 function together in a positive feedback loop to promote each other’s activity. That is, the SIN promotes cytoplasmic retention of Clp1, and cytoplasmic Clp1 antagonizes CDK activity and reverses CDK inhibition on the SIN pathway to promote its function and activity. However, at the start of this thesis, the mechanism by which the SIN regulated Clp1 was unknown. The SIN pathway is also required to promote constriction of the actomyosin ring, and the septum formation. However, its downstream targets were still uncharacterized. In two separate studies, we studied how Clp1 is released from the nucleolus at mitotic entry and how the SIN kinase Sid2 acts to retain Clp1 in the cytoplasm. We identified several Sid2 candidate substrates, and revealed other functions of the SIN pathway in coordinating mitotic events

Molecular First Hyperpolarizabilities of a New Class of Asymmetric Squaraine Dyes

The molecular first hyperpolarizabilities (β) of a series of asymmetric squaraine dyes have been measured by electric-field-induced second harmonic generation; the dyes have negative β-values whose magnitudes are comparable to 4-N,N-dimethylamino-4′-nitrostilbene (DANS)

Global Competition Made 2018 a Bad Time to Start a Trade War

The United States is one of the largest players in the international agricultural market. With the continued growth of its agricultural output, the US agricultural sector has relied heavily on export markets to maintain its competitiveness and profitability. In fact, projections show the United States will export $137 billion in agricultural commodities in 2020 (Daugherty and Jiang 2019)

The United States’ Competitive Positions in Beef, Corn, Pork, Soy, and Wheat Exports: 1980–2019

In a recent publication, CARD researchers and USDA economists looked at the international relationships between the United States and its major export competitors in beef (Chen et al. 2020). In that article, the researchers examined beef because the 2004 bovine spongiform encephalopathy (“mad cow disease”) event caused a major disruption in US beef exports and the United States’ competitive position. The authors conclude that even when exports return to pre-disruption levels, the disruption could change the structure of the export market. What the researchers found was that it took much longer for the United States’ competitive position in beef to return to pre-disruption levels

A Fortune from Misfortune: Evidence from Hog Firms’ Stock Price Responses to China’s African Swine Fever

China is the world’s largest pork producer and a leading pork importer. Since Au- gust 2018, ongoing outbreaks of African Swine Fever (ASF), a highly contagious and deadly disease affecting pigs, have hit China’s livestock industries and wiped out 40% of China’s pigs. We leverage data on daily stock returns from 25 major publicly listed firms from China and eight major pork-exporting countries to provide the first systematic analysis of the firm-level economic impacts of the outbreaks. We find that on average announcements of ASF outbreaks have led to positive and significant stock returns for both Chinese and international hog companies. Notably, Chinese hog companies on average enjoyed 10%–40% of cumulative abnormal returns during the 2019 Chinese Spring Festival, a peak demand season for pork. We show that larger hog firms tend to capture greater positive stock returns. Our results suggest opportunities for consolidation, expansion, and upgrades of China’s meat industry that have long-run implications for its global competitiveness and efficiency

Large Hog Companies Gain from China’s Ongoing African Swine Fever

It has been almost two years since China first reported an outbreak of African Swine Fever (ASF). As of June 5, 2020, China’s Ministry of Agriculture and Rural Affairs (MARA) had reported more than 177 ASF outbreaks, which resulted in an almost 32% reduction in hog and sow inventories since November 2018. These reductions—103 million pigs and 8.7 million sows—account for more than one-fifth of the world’s hog inventory (figure 1)

Identification using Valanis model for beams with nonlinear bolted joint and boundary connection

Bolted joints are widely applied in assembled mechanical structures. This paper focuses on the nonlinear modeling and parameter identification of bolted beams. Two Valanis models are respectively used to describe the nonlinear behaviors of the bolted joint and the boundary connection. Experimental tests at low and high excitation levels are performed to reveal the dynamic characteristics of the bolted beams. The Young’s modulus of the beams is identified via experimental test with low excitation level; whereas the parameters of Valanis model are identified by using optimization technique in order to minimize the residual error between the measured and the simulation data at a high excitation level

Sized-based Regulation and Environmental Quality: Evidence from the US Livestock Industry

The growing prevalence of animal feeding operations (AFOs) in the United States raises concerns among the public and regulators about their impact on local environmental quality. This paper studies the effects of Clean Water Act regulations that targeted water pollution from the largest hog AFOs. We compile a novel dataset linking historical regulatory records of AFOs in Iowa to downstream surface water pollution monitors. The regulation decreased ammonia concentrations downstream of large AFOs by 6 to 9 percentage points and modestly improved dissolved oxygen concentrations, but did not reduce phosphorus concentrations. Pollution reductions are largest during heavy precipitation months, consistent with the regulations reducing on-site spills and nutrient runoff from local fields. However, we find that pollution increased downstream from mid-sized AFOs, which were exempt from the regulations. Given the growth in the number of mid-sized facilities relative to large AFOs, we estimate that the regulation had little discernible impact on overall water quality