Positive Log-linear Relationship Research Articles

Determining the relationship between mobile phone network signal strength and radiofrequency electromagnetic field exposure: protocol and pilot study to derive conversion functions

Mobile phones continuously monitor and evaluate indicators of the received signal strengths from surrounding base stations to optimise wireless services. These signal strength indicators (SSIs) offer the potential for assessing radiofrequency electromagnetic field (RF-EMF) exposure on a population scale, as they can be related to exposure from both base stations and handset devices. Within the ETAIN (Exposure To electromAgnetic fields and plaNetary health) project, an open-access RF-EMF exposure app for smartphones, named "5G Scientist Monitor”, has been developed using citizen science. This paper delineates a measurement protocol for deriving formulas to convert the app SSIs into electric field values to estimate RF-EMF exposure. It presents pilot study results from measurements taken at four locations in Lyon, France (FR), and 14 locations in the Netherlands (NL), using three different phone models and the most common network providers in each country. The measurements were conducted while executing different usage scenarios, such as calls or data transmission. The exposimeter ExpoM-RF4 and on-body electric field probes were used to measure exposure from far-field sources and the handset, respectively. Two-minute aggregates were considered the sample unit for analyses (n=891 in NL and n=395 in FR). Regression analyses showed a positive log-linear relationship between Long Term Evolution (LTE) SSIs and far-field RF-EMF exposure when aggregating data by location (coefficients for the normalised RSSI: 0.91 [95% CI: 0.55 - 1.28] in FR, 1.09 [95% CI: 0.96 - 1.22] in NL). Negative log-linear trends were observed for handset-related RF-EMF exposure at the ear (-0.31 [95% CI: -0.46 - -0.16]) and chest (-0.20 [95% CI: -0.37 - -0.03]) during data transmission scenarios. These results demonstrate that the 5G-Scientist-Monitor app can be implemented for smartphone-based RF-EMF estimation. However, uncertainties in individual measurement points highlight the need for further data collection and analysis to improve the accuracy of exposure estimates.

Why Does Surprisal From Larger Transformer-Based Language Models Provide a Poorer Fit to Human Reading Times?

AbstractThis work presents a linguistic analysis into why larger Transformer-based pre-trained language models with more parameters and lower perplexity nonetheless yield surprisal estimates that are less predictive of human reading times. First, regression analyses show a strictly monotonic, positive log-linear relationship between perplexity and fit to reading times for the more recently released five GPT-Neo variants and eight OPT variants on two separate datasets, replicating earlier results limited to just GPT-2 (Oh et al., 2022). Subsequently, analysis of residual errors reveals a systematic deviation of the larger variants, such as underpredicting reading times of named entities and making compensatory overpredictions for reading times of function words such as modals and conjunctions. These results suggest that the propensity of larger Transformer-based models to ‘memorize’ sequences during training makes their surprisal estimates diverge from humanlike expectations, which warrants caution in using pre-trained language models to study human language processing.

Pentraxin-3 is a candidate biomarker on the spectrum of severity from pre-eclampsia to HELLP syndrome: GenPE study.

Pentraxin-3 has been reported as a promising biomarker of pre-eclampsia and its severity; however, available studies have small sample sizes, and analyses are not always adjusted for confounders. The aim of this study is to establish the strength of the association between maternal Pentraxin-3 level and pre-eclampsia or HELLP syndrome. It was a case-control study. Women with pre-eclampsia or HELLP syndrome were defined as cases, and women with healthy pregnancies at term (>37 weeks) were classified as controls. Plasma concentrations of Pentraxin-3 were determined at the time of delivery by quantitative enzyme immunoassay. Associations between Pentraxin-3 and pre-eclampsia and HELLP syndrome were assessed by multinomial logistic regression. Subsidiary analysis for the time of disease onset was also carried out. Odds ratios and 95% confidence intervals are reported. A total of 1024 pregnant women were included (461 controls, 368 pre-eclampsia, 195 HELLP). A positive log-linear relationship was found between the top pentraxin-3 quintile and HELLP syndrome. After adjustment for confounders (maternal age, ethnicity, socioeconomic position, date and place of recruitment, family history of pre-eclampsia, smoking, body mass index at beginning of pregnancy, gestational age and multiple pregnancy), the strength of the association was higher for HELLP syndrome [OR 1.13 (95% CI 1.08; 1.18)] than for pre-eclampsia [OR 1.03 (95% CI 1.03; 1.10)]. No difference according to time of onset or pentraxin-3 level was found. In summary, pentraxin-3 level was associated with pre-eclampsia, but it was more strongly associated with HELLP syndrome. Longitudinal studies with a lower probability of residual confounding are necessary to improve our knowledge about the role of pentraxin-3 in pre-eclampsia.

Associations of General and Central Adiposity With Incident Diabetes in Chinese Men and Women.

We assess associations of general and central adiposity in middle age and of young adulthood adiposity with incident diabetes in adult Chinese and estimate the associated population burden of diabetes. The prospective China Kadoorie Biobank enrolled 512,891 adults 30-79 years of age from 10 localities across China during 2004-2008. During 9.2 years of follow-up, 13,416 cases of diabetes were recorded among 482,589 participants without diabetes at baseline. Cox regression yielded adjusted hazard ratios (HRs) for incident diabetes associated with measures of general (e.g., BMI and BMI at 25 years) and central (e.g., waist circumference [WC]) adiposity. The mean (SD) BMI was 23.6 kg/m2 (3.4 kg/m2), and 3.8% had a BMI ≥30 kg/m2. Throughout the range examined (19-32 kg/m2), BMI showed a positive log-linear relationship with diabetes, with adjusted HRs per SD higher usual BMI greater in men (1.98; 95% CI 1.93-2.04) than in women (1.77; 1.73-1.81) (P for heterogeneity <0.001). For WC, HRs per SD were 2.13 (95% CI 2.07-2.19) in men and 1.91 (1.87-1.95) in women (P for heterogeneity <0.001). Mutual adjustment attenuated these associations, especially those of BMI. BMI at age 25 years was weakly positively associated with diabetes (men HR 1.09 [95% CI 1.05-1.12]; women 1.04 [1.02-1.07] per SD), which was reversed after adjustment for baseline BMI. In China, the increase in adiposity accounted for ∼50% of the increase in diabetes burden since 1980. Among relatively lean Chinese adults, higher adiposity-general and central-was strongly positively associated with the risk of incident diabetes. The predicted continuing increase in adiposity in China foreshadows escalating rates of diabetes.

Internal and External Factors of Future Returns in the Banking Business: Time Series Analysis of Interrelationship

The paper seeks to find the interrelationship between internal and external factors of future returns in the banking business. A multivariate time series regression models are fitted for the dependent variable: return on equity (ROE) against the lag one independent variables, namely: deposit, size, loan, capital, inflation, gross domestic product (GDP) and stock market capitalization (SMC), for ABSA bank; using secondary data, which span from 1998 to 2014 fiscal years. Logarithm transformation of the absolute value of the de-trended data and first differencing at lag one were the smoothing techniques applied to the data. Multivariate time series regression by the least square approach with special consideration of the stepwise method was used in fitting the models to the data. Results indicated that first, there is a positive linear relationship between ROE and loans, a negative linear relationship between ROE and inflation from the differencing techniques; and equally a negative log-linear relationship between ROE and capital as well as a positive log-linear relationship between ROE and ROA for the logarithm de-trend technique.

Internal and External Factors of Future Returns in the Banking Business: Time Series Analysis of Interrelationship

The paper seeks to find the interrelationship between internal and external factors of future returns in the banking business. A multivariate time series regression models are fitted for the dependent variable: return on equity (ROE) against the lag one independent variables, namely: deposit, size, loan, capital, inflation, gross domestic product (GDP) and stock market capitalization (SMC), for ABSA bank; using secondary data, which span from 1998 to 2014 fiscal years. Logarithm transformation of the absolute value of the de-trended data and first differencing at lag one were the smoothing techniques applied to the data. Multivariate time series regression by the least square approach with special consideration of the stepwise method was used in fitting the models to the data. Results indicated that first, there is a positive linear relationship between ROE and loans, a negative linear relationship between ROE and inflation from the differencing techniques; and equally a negative log-linear relationship between ROE and capital as well as a positive log-linear relationship between ROE and ROA for the logarithm de-trend technique.

Mechanistic insights into the role of river sediment in the attenuation of the herbicide isoproturon

Mechanistic insights into the relative contribution of sorption and biodegradation on the removal of the herbicide isoproturon (IPU) are reported. 14C-radiorespirometry indicated very low levels of catabolic activity in IPU-undosed and IPU-dosed (0.1, 1, 100 μg L−1) river water (RW) and groundwater (GW) (mineralisation: <2%). In contrast, levels of catabolic activity in IPU-undosed and IPU-dosed river sediment (RS) were significantly higher (mineralisation: 14.5–36.9%). Levels of IPU catabolic competence showed a positive log-linear relationship (r2 = 0.768) with IPU concentration present. A threshold IPU concentration of between 0.1 μg L−1 and 1 μg L−1 was required to significantly (p < 0.05) increase levels of catabolic activity. Given the EU Drinking Water Directive limit for a single pesticide in drinking water of <0.1 μg L−1 this result suggests that riverbed sediment infiltration is potentially an appropriate ‘natural’ means of improving water quality in terms of pesticide levels at concentrations that are in keeping with regulatory limits.

Genotypic richness and phenotypic dissimilarity enhance population performance

Increases in biodiversity can result from an increase in species richness, as well as from a higher genetic diversity within species. Intraspecific genetic diversity, measured as the number of genotypes, can enhance plant primary productivity and have cascading effects at higher trophic levels, such as an increase in herbivore and predator richness. The positive effects of genotypic mixtures are not only determined by additive effects, but also by interactions among genotypes, such as facilitation or inhibition. However, so far there has been no effort to predict the extent of such effects. In this study, we address the question of whether the magnitude of the effect of genotype number on population performance can be explained by the extent of dissimilarity in key traits among genotypes in a mixture. We examine the relative contribution of genotype number and phenotypic dissimilarity among genotypes to population performance of the soil arthropod, Orchesella cincta. Nearly homogeneous genotypes were created from inbred isofemale lines. Phenotypic dissimilarity among genotypes was assessed in terms of three life-history traits that are associated with population growth rate, i.e., egg size, egg development time, and juvenile growth rate. A microcosm experiment with genotype mixtures consisting of one, two, four, and eight genotypes, showed that genotypic richness strongly increased population size and biomass production and was associated with greater net diversity effects. Most importantly, there was a positive log-linear relationship between phenotypic dissimilarity in a mixture and the net diversity effects for juvenile population size and total biomass. In other words, the degree of phenotypic dissimilarity among genotypes determined the magnitude of the genotypic richness effect, although this relationship leveled off at higher values of phenotypic dissimilarity. Although the exact mechanisms responsible for these effects are currently unknown, similar advantages of trait dissimilarity have been found among species. Hence, to better understand population performance, genotype number and phenotypic dissimilarity should be considered collectively.

The prognostic value of adipose tissue fatty acids for incident cardiovascular disease: results from 3944 subjects in the Scottish Heart Health Extended Cohort Study

Dietary fats are routinely considered key determinants of cardiovascular risk, yet the scientific basis of this association has never been demonstrated using objective measures of fat intakes in a large prospective study in a general population. Adipose tissue was taken from 3944 participants, predominantly aged 40-59 years, in Scotland, 1984-87. Percentages of individual fatty acids were measured using gas chromatography. Over a median of 19.5 years, 870 incident cardiovascular disease (CVD) events occurred. Hazard ratios (HRs) were obtained from Cox models and the additional prognostic value, accounting for variables in the Framingham and ASSIGN CVD risk scores, were assessed using discrimination indices. Adjusting for age, sex, total and HDL-cholesterol, systolic blood pressure, smoking, hypertensive medication use, diabetes, socio-economic status and family history, the percentage of monounsaturated adipose tissue fatty acids had a positive log-linear relationship with incident CVD: the HR comparing risk between the fourth and first quartiles was 1.29 (95% confidence interval: 1.05, 1.59). n-3 polyunsaturated fat showed the reverse trend, the corresponding result being 0.77 (0.63, 0.94). These two composite variables improved the classification of incident CVD events by 1.0 and 6.4%, respectively, with only the latter being significant at the 5% level. A diet which is proportionately rich in polyunsaturated fat, as opposed to other fats, is expected to decrease the risk of CVD independently of the effects of common CVD risk factors, including social deprivation. Taking account of such diets improves the classification of future CVD events.

Quantitative Links Between Pacific Salmon and Stream Periphyton

Species’ impacts on primary production can have strong ecological consequences. In freshwater ecosystems, Pacific salmon (Oncorhynchus spp.) may influence stream periphyton through substrate disturbance during spawning and nutrient subsidies from senescent adults. The shape of relationships between the abundance of spawning salmon and stream periphyton, as well as interactions with environmental variables, are incompletely understood and may differ across the geographic range of salmon. We examined these relationships across 24 sockeye salmon (Oncorhynchus nerka) spawning streams in north-central British Columbia, Canada. The influence of salmon abundance and environmental variables (temperature, light, dissolved nutrients, water velocity, watershed size, and invertebrate grazer abundance) on post-spawning periphyton abundance and nitrogen stable isotope signatures, which can indicate the uptake of salmon nitrogen, was evaluated using linear regression models and Akaike Information Criterion. Periphyton nitrogen stable isotope signatures were best described by a positive log-linear relationship with an upstream salmon abundance metric that includes salmon from earlier years. This suggests the presence of a nutrient legacy. In contrast, periphyton abundance was negatively related to the spawning-year salmon density, which likely results from substrate disturbance during spawning, and positively related to dissolved soluble reactive phosphorus prior to spawning, which may indicate phosphorus limitation in the streams. These results suggest that enrichment from salmon nutrients does not always translate into elevated periphyton abundance. This underscores the need to directly assess the outcome of salmon impacts on streams rather than extrapolating from stable isotope evidence for the incorporation of salmon nutrients into food webs.

Agricultural and biofuel implications of a species diversity experiment with native perennial grassland plants

Two primary approaches to perennial biofuel crop production studied so far are fertilized grass monocultures and low-input high-diversity grasslands. While high-yielding perennial grass varieties are being developed in fertilized monocultures, breeding for yield in low-input high-diversity systems would be difficult. Before initiating breeding for low-input systems, it is therefore important to know the minimum number of functional groups and species required for maximum biomass harvest from low-input grasslands. We controlled the number of perennial grassland species in 168 plots in Minnesota, USA. Species were selected at random from a pool of 18, and 1, 2, 4, 8, or 16 were planted in each plot. Aboveground biomass was measured annually, and the plots were burned each spring. We found a strongly positive log-linear relationship between average annual aboveground biomass and planted species number, but a large proportion of plot-to-plot variability remained unexplained. We performed a conditional analysis of the aboveground biomass data to determine whether considering species identity would reduce the minimum number of species necessary in order to achieve yields similar to the highest diversity treatments. A model that accounted for the presence of legumes in general, and for the presence of the legume species Lupinus perennis in particular, showed no increase in biomass yield with increased species number. Over 11 years, average yields of L. perennis/C 4 grass bicultures were similar to those of 16-species (maximum diversity) plots, and both were >200% greater than the average of monocultures. Thus, under low-input conditions, the choice of the appropriate few perennial plant species for each location might result in systems with biomass yields similar to those from high-diversity systems. Because breeding biofuel crops in diverse mixtures would introduce complexity that is unwarranted in terms of maximum biomass yield, the first biofuel crop breeding programs for low-input systems are likely to accelerate progress by focusing on grass–legume bicultures.

A comparison of methods for stock assessment of the Norway lobster, Nephrops norvegicus, in the Firth of Clyde

The abundance and biomass of the Firth of Clyde Nephrops norvegicus stock was estimated using two fishery independent techniques, back-calculation of spawning stock size from larval surveys and production estimates, and burrow counts from an underwater television survey. Larval production estimates were available from two separate investigations in different parts of the Firth of Clyde in 1984 and 1990. The annual larval production estimates from the two studies were divided by a relative density weighted mean fecundity (allowing for ovary resorption and egg loss during incubation) to estimate the numbers of spawning females. Length, weight and sex ratio data were then used to estimate the total stock biomass. The results from the two studies were combined to provide an overall estimate for the Firth of Clyde, of approximately 11,100 tonnes. Counts of burrows, obtained from television camera surveys in 1993, were used to estimate N. norvegicus densities and abundance and the latter value, multiplied by mean weight of individuals from trawl samples, gave a stock biomass estimate of about 8000 tonnes for the Firth of Clyde. The estimates from the two techniques compare reasonably well with recent analytical estimates based on fishery data from the same area. Trawl sampling at the same locations chosen for the TV survey indicated a positive log-linear relationship between burrow density and trawl catch rate suggesting the possibility that, with careful planning, trawl surveys could also be used for stock surveys. There was also a positive log-linear relationship between TV counts of emerged N. norvegicus and burrow density suggesting that the proportion of the population out of their burrows and available to trawling was relatively greater at high densities.