Search, Effort, and Locus of Control

We test the hypothesis that locus of control – one's perception of control over events in life – influences search by affecting beliefs about the efficacy of search effort in a laboratory experiment. We find that reservation offers and effort are increasing in the belief that one's efforts influence outcomes when subjects exert effort without knowing how effort influences the generation of offers but are unrelated to locus of control beliefs when subjects are informed about the relationship between effort and offers. These effects cannot be explained by locus of control's correlation with unmeasured human capital, personality traits, and the costs of search – alternative explanations for the relationships between locus of control and search behavior that cannot be ruled out using survey data – as the search task does not vary across treatments, which leads us to conclude that locus of control influences search through beliefs about the efficacy of search effort. Our findings provide evidence that locus of control measures can be used to identify job seekers at risk of becoming "discouraged" and abandoning search.locus of control, reservation wages, labor market search, experiment

Leveraging Spatial Diversity to Mitigate Partial Band Interference in Undersea Networks through Waveform Reconstruction

Many acoustic channels suffer from interference which is neither narrowband nor impulsive. This relatively long duration partial band interference can be particularly detrimental to system performance. We survey recent work in interference mitigation as background motivation to develop a spatial diversity receiver for use in underwater networks. The network consists of multiple distributed cabled hydrophones that receive data transmitted over a time-varying multipath channel in the presence of partial band interference produced by interfering active sonar signals as well as marine mammal vocalizations. In operational networks, many “dropped” messages are lost due to partial band interference which corrupts different portions of the received signal depending on the relative position of the interferers, information source and receivers due to the slow speed of propagation. Our algorithm has been tested on simulated data and is shown to work on an example from a recent undersea experiment

Applying Spatial Diversity to Mitigate Partial Band Interference in Undersea Networks

Many acoustic channels suffer from interference which is neither narrowband nor impulsive. This relatively long duration partial band interference can be particularly detrimental to system performance. We survey recent work in interference mitigation and orthogonal frequency division multiplexing (OFDM) as background motivation to develop a spatial diversity receiver for use in underwater networks. The network consists of multiple distributed cabled hydrophones that receive data transmitted over a time-varying multipath channel in the presence of partial band interference produced by interfering active sonar signals as well as marine mammal vocalizations. In operational networks, many “dropped” messages are lost due to partial band interference which corrupts different portions of the received signal depending on the relative position of the interferers, information source and receivers due to the slow speed of propagation

A Comparison of a Single Receiver and a Multi-Receiver Techniques to Mitigate Partial Band Interference

Many acoustic channels suffer from interference which is neither narrowband nor impulsive. This relatively long duration partial band interference can be particularly detrimental to system performance. We survey recent work in interference mitigation as background motivation to develop a spatial diversity receiver for use in underwater networks and compare this novel multi-receiver interference mitigation strategy with a recently developed single receiver interference mitigation algorithm using experimental data collected from the underwater acoustic network at the Atlantic Underwater Test and Evaluation Center. The network consists of multiple distributed cabled hydrophones that receive data transmitted over a time-varying multipath channel in the presence of partial band interference produced by interfering active sonar signals. In operational networks, many dropped messages are lost due to partial band interference which corrupts different portions of the received signal depending on the relative position of the interferers, information source and receivers due to the slow speed of propagation

Antenatal Corticosteroids and Neonatal Outcomes in Twins : A Systematic Review and Meta-analysis

Acknowledgements: Peter Socha is supported by a graduate training award from the Fonds de recherche du Québec – Santé. Rui Wang is supported by a National Health and Medical Research Council Emerging Leadership Investigator Grant (2009767). Presented at the Annual Meeting of Obstetrics and Gynaecology Scottish Trainees (AMOnGST) Conference, November 26, 2021 (online) and to be presented at the Royal College of Obstetricians and Gynecologists World Congress, June 13-15, 2022, in London, UK. Financial Disclosure Sohinee Bhattacharya reports money was paid to their institution from Tenovus Scotland, Medical Research Scotland, and MRC. They are a collaborator on the Co-Opt project funded by Wellcome trust and led by the University of Edinburgh. This project aims to look at the effects of antenatal corticosteroids on neonatal outcomes using IPD meta-analysis. The other authors did not report any potential conflicts of interest.Peer reviewedPostprin

The Michigan BioTrust for Health: Using Dried Bloodspots for Research to Benefit the Community While Respecting the Individual

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98798/1/j.1748-720X.2011.00577.x.pd

Changes in biological productivity along the northwest African margin over the past 20,000 years

Author Posting. © American Geophysical Union, 2016. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 31 (2016): 185–202, doi:10.1002/2015PA002862.The intertropical convergence zone and the African monsoon system are highly sensitive to climate forcing at orbital and millennial timescales. Both systems influence the strength and direction of the trade winds along northwest Africa and thus directly impact coastal upwelling. Sediment cores from the northwest African margin record upwelling-related changes in biological productivity connected to changes in regional and hemispheric climate. We present records of 230Th-normalized biogenic opal and Corg fluxes using a meridional transect of four cores from 19°N–31°N along the northwest African margin to examine changes in paleoproductivity since the last glacial maximum. We find large changes in biogenic fluxes synchronous with changes in eolian fluxes calculated using end-member modeling, suggesting that paleoproductivity and dust fluxes were strongly coupled, likely linked by changes in wind strength. Opal and Corg fluxes increase at all sites during Heinrich Stadial 1 and the Younger Dryas, consistent with an overall intensification of the trade winds, and changes in the meridional flux gradient indicate a southward wind shift at these times. Biogenic fluxes were lowest, and the meridional flux gradients were weakest during the African Humid Period when the monsoon was invigorated due to precessional changes, with greater rainfall and weaker trade winds over northwest Africa. These results expand the spatial coverage of previous paleoproxy studies showing similar changes, and they provide support for modeling studies showing changes in wind strength and direction consistent with increased upwelling during abrupt coolings and decreased upwelling during the African Humid Period.NSF Grant Numbers: OCE-1103262, OCE-1030784, OCE-0402348; Center for Climate and Life2016-07-2

Thorium isotopes tracing the iron cycle at the Hawaii Ocean Time-series Station ALOHA

Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 169 (2015): 1-16, doi:10.1016/j.gca.2015.07.019.The role of iron as a limiting micronutrient motivates an effort to understand the supply and removal of lithogenic trace metals in the ocean. The long-lived thorium isotopes (232 Th and 230 Th) in seawater can be used to quantify the input of lithogenic metals attributable to the partial dissolution of aerosol dust. Thus, Th can help in disentangling the Fe cycle by providing an estimate of its ultimate supply and turnover rate. Here we present time-series (1994-2014) data on thorium isotopes and iron concentrations in seawater from the Hawaii Ocean Time-series Station ALOHA. By comparing Th-based dissolved Fe fluxes with measured dissolved Fe inventories, we derive Fe residence times of 6-12 months for the surface ocean. Therefore, Fe inventories in the surface ocean are sensitive to seasonal changes in dust input. Ultrafiltration results further reveal that Th has a much lower colloidal content than Fe does, despite a common source. On this basis, we suggest Fe colloids may be predominantly organic in composition, at least at Station ALOHA. In the deep ocean (>2 km), Fe approaches a solubility limit while Th, surprisingly, is continually leached from lithogenic particles. This distinction has implications for the relevance of Fe ligand availability in the deep ocean, but also suggests Th is not a good tracer for Fe in deep waters. While uncovering divergent behavior of these elements in the water column, this study finds that dissolved Th flux is a suitable proxy for the supply of Fe from dust in the remote surface ocean.We acknowledge funding from the W.O. Crosby Postdoctoral Fellowship to CTH and the National Science Foundation through C-MORE, NSF-OIA EF-0424599 to EAB, and NSF-DMR Author Posting

Thorium isotopes tracing the iron cycle at the Hawaii Ocean Time-series Station ALOHA

The role of iron as a limiting micronutrient motivates an effort to understand the supply and removal of lithogenic trace metals in the ocean. The long-lived thorium isotopes (²³²Th and ²³⁰Th) in seawater can be used to quantify the input of lithogenic metals attributable to the partial dissolution of aerosol dust. Thus, Th can help in disentangling the Fe cycle by providing an estimate of its ultimate supply and turnover rate. Here we present time-series (1994–2014) data on thorium isotopes and iron concentrations in seawater from the Hawaii Ocean Time-series Station ALOHA. By comparing Th-based dissolved Fe fluxes with measured dissolved Fe inventories, we derive Fe residence times of 6–12 months for the surface ocean. Therefore, Fe inventories in the surface ocean are sensitive to seasonal changes in dust input. Ultrafiltration results further reveal that Th has a much lower colloidal content than Fe does, despite a common source. On this basis, we suggest Fe colloids may be predominantly organic in composition, at least at Station ALOHA. In the deep ocean (>2 km), Fe approaches a solubility limit while Th, surprisingly, is continually leached from lithogenic particles. This distinction has implications for the relevance of Fe ligand availability in the deep ocean, but also suggests Th is not a good tracer for Fe in deep waters. While uncovering divergent behavior of these elements in the water column, this study finds that dissolved Th flux is a suitable proxy for the supply of Fe from dust in the remote surface ocean.National Science Foundation (U.S.) (Grant NS-OIA E-0424599