Effective Proxy Research Articles

Avaliação do momentum no Brasil usando regressões quantílicas

Abstract The purpose of this study was to measure the relationship between expected returns and capital gains overhang (CGO) (a proxy for the disposition effect) in the Brazilian financial market. It also investigated the ability of the disposition effect to induce momentum. Quantile regression allows the study of the importance of extreme values in the regression. In this way, it is possible to study the relationship between the disposition effect and the expected return between losing and winning stocks using data for the Brazilian financial market. This may help explain the conflicting results found in the literature when studying this relationship in other countries. This study contributes to the development of the topic of the relationship between the disposition effect and unrealized capital gains in the financial market. For this, we apply Fama-MacBeth regression and quantile regression models. Initially, we study the relationship between CGO and expected return. Subsequently, we investigate the ability of the disposition effect to generate the momentum effect at extreme quantiles of expected return (0.05th - losing stocks and 0.95th - winning stocks). We used a sample of 227 shares of companies listed on the Brazilian stock exchange (B3) and monthly historical series from January 2000 to October 2018. We found a significant and positive relationship between CGO and expected return across different levels of expected return, decreasing from the lowest to the highest quantile of expected return. This indicates that Brazilian investors, who are prone to the disposition effect, operate at the extreme quantiles of expected return.

Statistical models of the variability of plasma in the topside ionosphere: 2. Performance assessment

Statistical models of the variability of plasma in the topside ionosphere based on the Swarm data have been developed in the “Swarm Variability of Ionospheric Plasma” (Swarm-VIP) project within the European Space Agency’s Swarm+4D-Ionosphere framework. The models can predict the electron density, its gradients for three horizontal spatial scales – 20, 50 and 100 km – along the North-South direction and the level of the density fluctuations. Despite being developed by leveraging on Swarm data, the models provide predictions that are independent of these data, having a global coverage, fed by various parameters and proxies of the helio-geophysical conditions. Those features make the Swarm-VIP models useful for various purposes, which include the possible support for already available ionospheric models and proxy of the effect of ionospheric irregularities of the medium scales that affect the signals emitted by Global Navigation Satellite Systems (GNSS). The formulation, optimisation and validation of the Swarm-VIP models are reported in Paper 1 (Wood et al. 2024. J Space Weather Space Clim. in press). This paper describes the performance assessment of the models, by addressing their capability to reproduce the known climatological variability of the modelled quantities, and the ionospheric weather as depicted by ground-based GNSS, as a proxy for the ionospheric effect on GNSS signals. Additionally, we demonstrate that, under certain conditions, the model can better reproduce the ionospheric variability than a physics-based model, namely the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM).

Assessing the relevance of energy indicators as sustainability screening metrics for the decarbonisation of industrial heat through electrification

Power generation faces the challenge of reducing its greenhouse gas emissions without shifting the burden to other environmental impacts. Energy and exergy-based environmental indicators have proven to some extent to be effective environmental proxies for the current energy mix but the robustness of this approach has barely been discussed in the frame of energy transition scenarios. Hence, the aim of this study is to analyse their relevance in the context of decarbonisation of industrial heat through electrification. To this end, we investigate the potential relationships between two different energy indicators and environmental indicators using life cycle assessment (Ecoinvent database, 16 environmental indicators, 2 energy indicators) for 28 pairs of energy sources shifting for the production of 1 kWh of electricity. For the reference French case, no similar trends across all sources of energy, for given environmental and energy indicators are found neither between all environmental and energy indicators. The extension to other cases is discussed, leading to the same conclusion. These results highlight the need for a multi-criteria assessment to evaluate the impacts of industrial heat in a context of intensive process electrification, which will be country dependent because of the various strategies in achieving net-zero electricity mix.

Root and rhizosphere contribution to the net soil COS exchange

Background and aimsPartitioning the measured net ecosystem carbon dioxide (CO2) exchange into gross primary productivity (GPP) and ecosystem respiration remains a challenge, which scientists try to tackle by using the properties of the trace gas carbonyl sulfide (COS). Its similar pathway into and within the leaf makes it a potential photosynthesis proxy. The application of COS as an effective proxy depends, among other things, on a robust inventory of potential COS sinks and sources within ecosystems. While the soil received some attention during the last couple of years, the role of plant roots is mostly unknown. In our study, we investigated the effects of live roots on the soil COS exchange.MethodsAn experimental setup was devised to measure the soil and the belowground plant parts of young beech trees observed over the course of 9 months.ResultsDuring the growing season, COS emissions were significantly lower when roots were present compared to chambers only containing soil, while prior to the growing season, with photosynthetically inactive trees, the presence of roots increased COS emissions. The difference in the COS flux between root-influenced and uninfluenced soil was fairly constant within each month, with diurnal variations in the COS flux driven primarily by soil temperature changes rather than the presence or absence of roots.ConclusionWhile the mechanisms by which roots influence the COS exchange are largely unknown, their contribution to the overall ground surface COS exchange should not be neglected when quantifying the soil COS exchange.

Humification levels of dissolved organic matter in the eastern plain lakes of China based on long-term satellite observations

Under the influence of intensive human activities and global climate change, the sources and compositions of dissolved organic matter (DOM) in the eastern plain lake (EPL) region in China have fluctuated sharply. It has been successfully proven that the humification index (HIX), which can be derived from three-dimensional excitation-emission matrix fluorescence spectroscopy, can be an effective proxy for the sources and compositions of DOM. Therefore, combined with remote sensing technology, the sources and compositions of DOM can be tracked on a large scale by associating the HIX with optically active components. Here, we proposed a novel HIX remote sensing retrieval (IRHIX) model suitable for Landsat series sensors based on the comprehensive analysis of the covariation mechanism between HIX and optically active components in different water types. The validation results showed that the model runs well on the independent validation dataset and the satellite-ground synchronous sampling dataset, with an uncertainty ranging from 30.85 % to 36.92 % (average ± standard deviation = 33.6 % ± 3.07 %). The image-derived HIX revealed substantial spatiotemporal variations in the sources and compositions of DOM in 474 lakes in the EPL during 1986–2021. Subsequently, we obtained three long-term change modes of the HIX trend, namely, significant decline, gentle change, and significant rise, accounting for 74.68 %, 17.09 %, and 8.23 % of the lake number, respectively. The driving factor analysis showed that human activities had the most extensive influence on the DOM humification level. In addition, we also found that the HIX increased slightly with increasing lake area (R2 = 0.07, P < 0.05) or significantly with decreasing trophic state (R2 = 0.83, P < 0.05). Our results provide a new exploration for the effective acquisition of long-term dynamic information about the sources and compositions of DOM in inland lakes and provide important support for lake water quality management and restoration.

Solar‐Induced Fluorescence Helps Constrain Global Patterns in Net Biosphere Exchange, as Estimated Using Atmospheric CO2 Observations

AbstractSolar‐induced chlorophyll fluorescence (SIF) shows enormous promise as a proxy for photosynthesis and as a tool for modeling variability in gross primary productivity and net biosphere exchange (NBE). In this study, we explore the skill of SIF and other vegetation indicators in predicting variability in global atmospheric CO2 observations, and thus global variability in NBE. We do so using a 4‐year record of CO2 observations from NASA's Orbiting Carbon Observatory 2 satellite and using a geostatistical inverse model. We find that existing SIF products closely correlate with space‐time variability in atmospheric CO2 observations, particularly in the extratropics. In the extratropics, all SIF products exhibit greater skill in explaining variability in atmospheric CO2 observations compared to an ensemble of process‐based CO2 flux models and other vegetation indicators. With that said, other vegetation indicators, when multiplied by photosynthetically active radiation, yield similar results as SIF and may therefore be an effective structural SIF proxy at regional to global spatial scales. Furthermore, we find that using SIF as a predictor variable in the geostatistical inverse model shifts the seasonal cycle of estimated NBE and yields an earlier end to the growing season relative to other vegetation indicators. These results highlight how SIF can help constrain global‐scale variability in NBE.

Comparative Persistence of Non-tumor Necrosis Factor (TNF) vs. TNF Antagonists for Post-operative Prophylaxis in Crohn's Disease (CD).

The comparative safety and effectiveness of available biologics for post-operative prophylaxis in Crohn's disease (CD) is uncertain. Drug persistence may serve as a real-world proxy for tolerability and effectiveness. We evaluated the comparative persistence of non-TNF and TNF antagonists for post-operative prophylaxis and their comparative effectiveness for preventing early endoscopic post-operative recurrence (POR). We conducted a single-center, retrospective study of surgically naïve CD subjects undergoing ileocecal or small bowel resection between 1/1/2000 and 12/31/2021 and prescribed a biologic for post-operative prophylaxis. We compared the risk of prophylaxis failure (requiring recurrent surgery or discontinuation of therapy due to persistent POR despite optimized drug level or dose escalation, immunogenicity, and/or adverse event) and early endoscopic POR (Rutgeert's score≥i2 within 15months postoperatively) between non-TNF and TNF antagonist prophylaxis using Cox proportional hazard and logistic regression, respectively, adjusting for demographic and disease characteristics. The study included 291 subjects (81% TNF antagonists). After multivariable adjustment, non-TNF antagonist prophylaxis was associated with a significantly lower risk of prophylaxis failure than TNF antagonists (hazard ratio 0.26; 95% confidence interval (CI) [0.13-0.53]). Prophylaxis with non-TNF and TNF antagonists had similar risk of early endoscopic POR (odds ratio 0.66; 95% CI [0.32-1.36]). Stratifying the non-TNF antagonists by anti-integrin and anti-IL12/23 yielded similar results. In a cohort of surgically naïve CD subjects prescribed a biologic for post-operative prophylaxis, non-TNF antagonists had greater persistence than TNF antagonists with similar risk for early endoscopic POR. If confirmed by large, prospective studies, these findings can inform post-operative management strategies in CD.

Examines the value of cloud computing adoption as a proxy for IT flexibility and effectiveness

PurposeThe purpose of this study is to investigate the value of cloud computing adoption (CCA) as a proxy for information technology (IT) flexibility (ITF) and IT effectiveness (ITE) among Small- and medium-sized enterprises (SMEs) in Jordan.Design/methodology/approachA research framework with five hypotheses has been developed based on the results of previous studies. Partial least squares-structural equation modeling has been used for data analysis.FindingsThe results revealed that elements of ITF in two domains, IT technical resource (connectivity, modularityand compatibility) and IT human resource (IT personnel skills) specific to CCA, were significantly correlated with ITE.Research limitations/implicationsThe findings have crucial implications: they contribute to the research community, administrators and cloud computing providers (CSPs) concerning the framework-improved procedure for CCA. The proposed model can enhance the awareness of service providers about why some SMEs accept cloud computing services, whereas actually the same ones having the same type of business do not. In addition, the above providers should enhance their interaction with the SMEs that contributed to the cloud computing knowledge to make a well-organized setting for the CCA, specifically, SMEs need that adopt an on-premise private cloud architecture. Moreover, necessary to determine the challenges in deploying solutions from the perspective of CSPs. The sample has been limited to Jordan respondents.Practical implicationsThe research studies about the usage of cloud computing have shown its effects on SMEs today. Also, the different impacts of cloud computing on other sectors are at the center of attention. SMEs could get significant advantages by carefully considering and managing CCA from the ITF and ITE perspective.Originality/valueTo the best of the author’s knowledge, this is the first study to develop a framework for CCA based on the standpoint of ITF in two domains, IT technical resources (connectivity, modularity and compatibility) and IT human resources (IT personnel skills) and effectiveness.

The bullwhip effect, demand uncertainty, and cost structure

AbstractThe firm‐level bullwhip effect is the amplification of demand uncertainty along a supply chain—that is, fluctuations in production (for manufacturing firms) or purchases from suppliers (for retailers or wholesalers) in a firm tend to be greater than its demand fluctuations. We predict that the bullwhip ratio (a proxy for the bullwhip effect) amplifies the relation between demand uncertainty and cost structure. We expect this amplifying effect because the bullwhip ratio determines the extent to which demand uncertainty translates into uncertainty in production or purchases, which, in turn, affects cost structure. Using data from public US firms over the 1990–2020 period, we find results consistent with our prediction. Specifically, we find that both the negative relation between demand uncertainty and cost elasticity in the manufacturing sector and the positive relation between the two in the retail/wholesale sectors are stronger for firms with higher bullwhip ratios. We contribute to the literature on cost structure by highlighting the important role of the bullwhip effect in cost structure decisions.

Audit committee characteristics as determinants of non-audit fees in UK FTSE 350 companies

PurposeThis study aims to examine trends in audit committee characteristics of companies and associates characteristics subject to major change with a fee-based proxy for audit committee effectiveness.Design/methodology/approachThe research adopts an empirical approach. Using descriptive and inferential statistics, observations for 253 Financial Times Stock Exchange 350 companies’ audit committee characteristics gathered from annual reports at the beginning and end of a five-year period are evaluated against averaged non-audit fees (NAF) as a proportion of total audit fees.FindingsAudit committee composition shows an increased incidence of female membership and of members with previous audit experience. The increase in members with previous audit experience is more marked where this is gained with the incumbent auditor. An increase is also shown in chief financial officers with previous audit experience. Previous audit experience is associated with reduced NAF as a proportion of total fees. This is marked where audit experience has been gained with the incumbent auditor. These results suggest that the benefits of financial expertise gained from audit experience outweigh impairments to independence due to social ties. Nevertheless, other studies indicate concerns about independence are still well-founded.Originality/valueThis paper’s original contribution is to evaluate the potential effect of previous audit experience on those involved in audit committees in light of concerns raised in the literature and by regulators that external auditor independence should be maintained. The innovative fee-based proxy for audit committee effectiveness facilitates an evaluation as to which influence prevails.

Herd behavior in cryptocurrency market: evidence of network effect

PurposeThis study examines herd behavior in the cryptocurrency market at the aggregate level and the determinants of herd behavior, such as asymmetric market returns, the coronavirus disease 2019 (COVID-19) pandemic, 2021 cryptocurrency's bear market and the network effect.Design/methodology/approachThe authors applied the Google Search Volume Index (GSVI) as a proxy for the network effect. Since investors who are interested in a particular issue have a common interest, they tend to perform searches using the same keywords in Google and are on the same network. The authors also investigated the daily returns of cryptocurrencies, which are in the top 100 market capitalizations from 2017 to 2022. The authors also examine the association between return dispersion and portfolio return based on aggregate market herding model and employ interactions between herding determinants such as, market direction, market trend, COVID-19 and network effect.FindingsThe empirical results indicate that herding behavior in the cryptocurrency market is significantly captured when the market returns of cryptocurrency tend to decline and when the network effect of investors tends to expand (e.g. such as during the COVID-19 pandemic or 2021 Bitcoin crash). However, the results confirm anti-herd behavior in cryptocurrency during the COVID-19 pandemic or 2021 Bitcoin crash, regardless of the network effect.Practical implicationsThese findings help investors in the cryptocurrency market make more rational decisions based on their determinants since cryptocurrency is an alternative investment for investors' asset allocation. As imitating trades lead to return comovement, herd behavior in the cryptocurrency has a direct impact on the effectiveness of portfolio diversification. Hence, market participants or investors should consider herd behavior and its underlying factors to fully maximize the benefits of asset allocation, especially during the period of market uncertainty.Originality/valueMost previous studies have focused on herd behavior in the stock market. Although some researchers have recently begun studying herd behavior in the cryptocurrency market, the empirical results are inconclusive due to an incorrectly specified model or unclear determinants.

Thermal maturity calculation in Type II-S source rocks using the alkyl dibenzothiophenes

Distributions of the alkyl dibenzothiophenes (DBT) are proven as effective proxies for the thermal maturity of bitumen extracts and oils expelled from marine source rocks containing Type II-S kerogen. Here we report on an expanded sample suite and DBT ratios to further refine these relationships. This study investigates the methyldibenzothiophenes (MDBT), dimethyldibenzothiophenes (DMDBT), and trimethyldibenzothiophenes (TMDBT) in 52 source rocks from formations in the United States and the Middle East to substantiate the reliability of these sulfur-bearing compounds to estimate maturity in Type II-S samples. The isomerization of MDBTs, DMDBTs, and TMDBTs shows strong correlations with pyrolysis data (Tmax, hydrogen index, and equivalent %VRo), enabling a direct calculation of thermal maturity from the ratios of the MDBT homologous series. Maturity indicators from biomarkers and other ancillary compounds are also analyzed to highlight the limitations and inconsistencies that can be observed when applying such methods to assess the maturity of Type II-S samples. The derived MDBT, DMDBT, and TMDBT maturity equations provide a reliable assessment of maturity for Type II-S samples, ranging from the immature window to the end of the condensate/wet gas window. Moreover, evaluation of 18 sulfur-rich oils validates the application of MDR maturity equations to fluid samples. Such flexibility allows for inclusive, yet consistent, maturity assessment in sulfur-rich formations when compared to other molecular maturity proxies.

The incidence and risk factors of selected drug prescriptions and outpatient care after SARS-CoV-2 infection in low-risk subjects: a multicenter population-based cohort study.

Knowledge about the dynamics of transmission of SARS-CoV-2 and the clinical aspects of COVID-19 has steadily increased over time, although evidence of the determinants of disease severity and duration is still limited and mainly focused on older adult and fragile populations. The present study was conceived and carried out in the Emilia-Romagna (E-R) and Veneto Regions, Italy, within the context of the EU's Horizon 2020 research project called ORCHESTRA (Connecting European Cohorts to increase common and effective response to SARS-CoV-2 pandemic) (www.orchestra-cohort.eu). The study has a multicenter retrospective population-based cohort design and aimed to investigate the incidence and risk factors of access to specific healthcare services (outpatient visits and diagnostics, drug prescriptions) during the post-acute phase from day-31 to day-365 after SARS-CoV-2 infection, in a healthy population at low risk of severe acute COVID-19. The study made use of previously recorded large-scale healthcare data available in the administrative databases of the two Italian Regions. The statistical analysis made use of methods for competing risks. Risk factors were assessed separately in the two Regions and results were pooled using random effects meta-analysis. There were 35,128 subjects in E-R and 88,881 in Veneto who were included in the data analysis. The outcome (access to selected health services) occurred in a high percentage of subjects in the post-acute phase (25% in E-R and 21% in Veneto). Outpatient care was observed more frequently than drug prescriptions (18% vs. 12% in E-R and 15% vs. 10% in Veneto). Risk factors associated with the outcome were female sex, age greater than 40 years, baseline risk of hospitalization and death, moderate to severe acute COVID-19, and acute extrapulmonary complications. The outcome of interest may be considered as a proxy for long-term effects of COVID-19 needing clinical attention. Our data suggest that this outcome occurs in a substantial percentage of cases, even among a previously healthy population with low or mild severity of acute COVID-19. The study results provide useful insights into planning COVID-19-related services.

By What Criteria Do We Evaluate Accounting? Some Thoughts on Economic Welfare and the Archival Literature

ABSTRACTThe economic role of an accounting regime is to increase welfare through its effects—in conjunction with complementary institutions—on firm and household behavior. I review three major streams of the archival literature (real effects; price effects, including value relevance; and costly contracting), in terms of what they can and cannot reveal as proxies for welfare effects. One conclusion is that the partial correlations and average effects that predominate in this literature have provided valuable insights into the role of accounting in the economy, but provide limited and misleading proxies for welfare effects. A major concern is that teachers, students, and researchers—indeed, regulators and standard setters—raised on this literature could lose sight of, and underestimate, the fundamental contribution of accounting to aggregate welfare.

Remove, Reduce, Inform: What Actions do People Want Social Media Platforms to Take on Potentially Misleading Content?

To reduce the spread of misinformation, social media platforms may take enforcement actions against offending content, such as adding informational warning labels, reducing distribution, or removing content entirely. However, both their actions and their inactions have been controversial and plagued by allegations of partisan bias. When it comes to specific content items, surprisingly little is known about what ordinary people want the platforms to do. We provide empirical evidence about a politically balanced panel of lay raters' preferences for three potential platform actions on 368 news articles. Our results confirm that on many articles there is a lack of consensus on which actions to take. We find a clear hierarchy of perceived severity of actions with a majority of raters wanting informational labels on the most articles and removal on the fewest. There was no partisan difference in terms of how many articles deserve platform actions but conservatives did prefer somewhat more action on content from liberal sources, and vice versa. We also find that judgments about two holistic properties, misleadingness and harm, could serve as an effective proxy to determine what actions would be approved by a majority of raters.

Genetic Insights on the Relation of Vascular Risk Factors and Cervical Artery Dissection

BackgroundThe association between vascular risk factors and cervical artery dissections (CeADs), a leading cause of ischemic stroke (IS) in the young, remains controversial. ObjectivesThis study aimed to explore the causal relation of vascular risk factors with CeAD risk and recurrence and compare it to their relation with non-CeAD IS. MethodsThis study used 2-sample Mendelian randomization analyses to explore the association of blood pressure (BP), lipid levels, type 2 diabetes, waist-to-hip ratio, smoking, and body mass index with CeAD and non-CeAD IS. To simulate effects of the most frequently used BP-lowering drugs, this study constructed genetic proxies and tested their association with CeAD and non-CeAD IS. In analyses among patients with CeAD, the investigators studied the association between weighted genetic risk scores of vascular risk factors and the risk of multiple or early recurrent dissections. ResultsGenetically determined higher systolic BP (OR: 1.51; 95% CI: 1.32-1.72) and diastolic BP (OR: 2.40; 95% CI: 1.92-3.00) increased the risk of CeAD (P < 0.0001). Genetically determined higher body mass index was inconsistently associated with a lower risk of CeAD. Genetic proxies for β-blocker effects were associated with a lower risk of CeAD (OR: 0.65; 95% CI: 0.50-0.85), whereas calcium-channel blockers were associated with a lower risk of non-CeAD IS (OR: 0.75; 95% CI: 0.63-0.90). Weighted genetic risk scores for systolic BP and diastolic BP were associated with an increased risk of multiple or early recurrent CeAD. ConclusionsThese results are supportive of a causal association between higher BP and increased CeAD risk and recurrence and provide genetic evidence for lower CeAD risk under β-blockers. This may inform secondary prevention strategies and trial design for CeAD.

Global trends in atmospheric layer thickness since 1940 and relationships with tropical and extratropical climate forcing

Global warming necessitates continual insights into changing atmospheric temperatures to enhance climate change monitoring and prediction. The thickness of an atmospheric layer serves as an effective proxy for the average temperature of that layer, playing a pivotal role in weather forecasting, understanding atmospheric dynamics, and detecting shifts in extreme weather conditions. This study investigates the global trends in thickness of the layer between 1000 hPa and 500 hPa, from 1940 to the present and evaluates the impact of tropical and extra-tropical climate modes on these trends. Our findings reveal a consistent, statistically significant positive trend in atmospheric layer thickness. However, the magnitude of this trend varies both regionally and seasonally. The most substantial absolute changes are observed in the high latitudes during their respective winter seasons; however, when considering global changes relative to each location’s unique historical variability, the most pronounced increase occurs in the tropics, specifically over central Africa, with a standard deviation increase of up to 0.03 σ yr−1. Based on the relative changes, the thickness over the Southern Hemisphere’s high-latitude landmasses is increasing at a faster pace during its winter compared to the Northern Hemisphere during its winter. Furthermore, our analysis of the impact of dominant tropical and extra-tropical climate modes revealed a strong correlation (R ∼ 0.9) between sea surface temperature changes in the Pacific warm pool region and the global average thickness. This relationship accounts for about 76% to 78% variance of the inter-annual variability in thickness. Consequently, we identify the increase in sea surface temperature in the Indo-Pacific warm pool as a significant controller of the rate and magnitude of atmospheric layer thickness changes globally. This underscores the crucial role of oceanic-atmospheric interactions in driving global climate variations and extremes.

An Investigation of the Suitability of Viscosity Detection in Estimating IgG Content in Mare Colostrum

An adequate supply of colostrum is important for the prevention of hypogammaglobulinaemia in foals. In addition to the quantity of colostrum consumed and the time of consumption, the quality of the colostrum, the immunoglobulin (Ig) G concentration, is crucial. The aim of this study was to determine whether the viscosity of equine colostrum was a suitable estimate of IgG concentration. IgG content of colostrum was measured by ELISA and viscosity directly measured with a cone plate viscometer and indirectly assessed with a funnel. Analysis of 56 colostrum samples obtained from 40 mares at different postpartum time points was conducted to assess colostrum samples with varying levels of quality. The range of IgG concentrations determined by ELISA was 0.83 to 245.5 mg/mL (30.69 ± 41.92 mg/mL). The range of viscosity values determined by the cone plate method was 1.84 to 110.00 cP (7.86 ± 17.48 cP) at a shear rate of 3 rpm. Colostrum drainage from the funnel (drainage time), varied between 7.9 and 30.0 s, with an average of 9.96 ± 4.48 s. As the data were not normally distributed, Spearman's rank correlation analyses were calculated and significant correlation found between viscosity and IgG content (ρ = 0.71, P < .001), as well as between drainage time and IgG content (ρ = 0.75, P < .001). These correlations indicate that determining the viscosity of equine colostrum by cone plate or drainage time, may be an effective proxy measurement of IgG content.

Maternal hemoglobin and iron status in early pregnancy and risk of respiratory tract infections in childhood: A population-based prospective cohort study.

Maternal hemoglobin and iron status measures during pregnancy might affect the developing fetal respiratory system leading to adverse respiratory conditions. Our aim was to assess the associations of maternal hemoglobin and iron status measures during pregnancy with the risk of respiratory tract infections in children until 10 years of age. In a population-based cohort study among 5134 mother-child pairs, maternal hemoglobin and iron status including ferritin, transferrin, and transferrin saturation were measured during early pregnancy. In children, physician-attended respiratory tract infections from age 6 months until 10 years were assessed by questionnaires. Confounder-adjusted generalized estimating equation modeling was applied. After taking multiple testing into account, high maternal ferritin concentrations and low maternal transferrin saturation during pregnancy were associated with an overall increased risk of upper, not lower, respiratory tract infections until age 10 years of the child [OR (95% CI: 1.23 (1.10, 1.38) and 1.28 (1.12, 1.47), respectively)]. High maternal transferrin saturation during pregnancy was associated with a decreased and increased risk of upper respiratory tract infections at 1 and 6 years, respectively, [OR (95% CI: 0.60 (0.44, 0.83) and 1.54 (1.17, 2.02))]. Observed associations were suggested to be U-shaped (p-values for non-linearity ≤.001). Maternal hemoglobin and iron status measures during pregnancy were not consistently associated with child's gastroenteritis and urinary tract infections, as proxies for general infection effects. High maternal ferritin and low transferrin saturation concentrations during early pregnancy were most consistently associated with an overall increased risk of child's upper, not lower, respiratory tract infections.

Quantifying Site Effects and Their Influence on Earthquake Source Parameter Estimations Using a Dense Array in Oklahoma

AbstractWe investigate the effects of site response on source parameter estimates using earthquakes recorded by the LArge‐n Seismic Survey in Oklahoma (LASSO). While it is well known that near‐surface unconsolidated sediments can cause an apparent breakdown of earthquake self‐similarity, the influence of laterally varying site conditions remains unclear. We analyze site conditions across the 1825‐station array on a river plain within an area of 40 km by 23 km using vertical ground motions from 14 regional earthquakes. While the source radiation pattern controls P‐wave ground motions below 8 Hz, the surface geology correlates with P‐wave ground motions above 8 Hz and S‐wave ground motions at 2–21 Hz. Stations installed in alluvial sediments have vertical ground motions that can exceed three times the array median. We use the variation of ground motion of regional earthquakes across the array as a proxy for site effects. The corner frequencies and stress drops of local earthquakes (ML = 0.01–3) estimated using a standard single‐spectra approach show negative correlations with the site‐effect proxy, while the seismic moments show positive correlations. In contrast, the spectral‐ratio approach effectively shows no correlation. The overall bias is small as expected for this relatively homogeneous structure; accurate estimation of site‐related biases requires at least 30 stations. Correcting for site‐related biases reduces the standard deviations of the source parameters by less than 13% of the total variations. Remaining variations are partially associated with source directivity and model misfits— as small earthquakes can have complex ruptures.