Campylobacter jejuni is a major cause of bacterial food-borne infection in the industrial world. There is evidence that C. jejuni is present in eggs and hatchery fluff, opening the possibility for ...vertical transmission from hens to progeny. Poultry operations in Iceland provide an excellent opportunity to study this possibility, since breeding flocks are established solely from eggs imported from grandparent flocks in Sweden. This leaves limited opportunity for grandparents and their progeny to share isolates through horizontal transmission. While Campylobacter was not detected in all grandparent flocks, 13 of the 16 egg import lots consisted of eggs gathered from one or more Campylobacter-positive grandparent flocks. No evidence of Campylobacter was found by PCR in any of the 10 relevant quarantine hatchery fluff samples examined, and no Campylobacter was isolated from the parent birds through 8 weeks, while they were still in quarantine rearing facilities. After the birds were moved to less biosecure rearing facilities, Campylobacter was isolated, and 29 alleles were observed among the 224 isolates studied. While three alleles were found in both Sweden and Iceland, in no case was the same allele found both in a particular grandparent flock and in its progeny. We could find no evidence for vertical transmission of Campylobacter to the approximately 60,000 progeny parent breeders that were hatched from eggs coming from Campylobacter-positive grandparent flocks. If vertical transmission is occurring, it is not a significant source for the contamination of chicken flocks with Campylobacter spp.
Summary
We aimed to study the risk of hip fracture and risk of hip arthroplasty among farmers in Sweden. Our results indicate that farming, representing an occupation with high physical activity, in ...men is associated with a lower risk of hip fracture but an increased risk of hip arthroplasty.
Introduction
The risks of hip fracture and hip arthroplasty are influenced by factors including socioeconomic status, education, urbanization, latitude of residence, and physical activity. Farming is an occupation encompassing rural living and high level of physical activity. Therefore, we aimed to study the risk of hip fracture and risk of hip arthroplasty among farmers in Sweden.
Methods
We studied the risk of hip fracture, and hip arthroplasty due to primary osteoarthritis, in all men and women aged 35 years or more in Sweden between 1987 and 2002. Documented occupations were available in 3.5 million individuals, of whom 97,136 were farmers. The effects of age, sex, income, education, location of residence, and occupation on risk of hip fracture or hip arthroplasty were examined using a modification of Poisson regression.
Results
A total of 4027 farmers and 93,109 individuals with other occupations sustained a hip fracture, while 5349 farmers and 63,473 others underwent a hip arthroplasty. Risk of hip fracture was higher with greater age, lower income, lower education, higher latitude, and urban area for all men and women. Compared to all other occupations, male farmers had a 20% lower age-adjusted risk of hip fracture (hazard ratio (HR) 0.80, 95%CI 0.77–0.84), an effect that was not seen in female farmers (HR 0.96, 95% CI 0.91–1.01). Both male and female farmers had a higher age-adjusted risk for hip arthroplasty.
Conclusions
Our results indicate that farming, representing an occupation with high physical activity, in men is associated with a lower risk of hip fracture but an increased risk of hip arthroplasty.
Weyl semimetals have recently attracted extensive attention due to their anomalous band structure manifested by topological properties that lead to some unusual and unique physical properties. We ...investigate novel features of surface plasmon polaritons in a slot waveguide comprised from two semi-infinite Weyl semimetals. We consider symmetric Voigt-Voigt and Faraday-Faraday configurations for plasmon polaritons in two interfaces of waveguide and show that the resulting dispersion is symmetric and the propagation of surface plasmon polaritons is bidirectional. We introduce exotic and novel asymmetric structures making use of difference in magnitude or orientation of chiral anomalies in two Weyl semimetals in both Voigt and Faraday configurations. These structures show a tremendous nonreciprocal dispersion and unidirectional propagation of surface plasmon polaritons. Moreover, we study a hybrid configuration of Voigt-Faraday for surface plasmon polartions in two interfaces of the waveguide. We find that this structure possesses unique futures. It shows surface plasmon polariton modes with unidirectional propagation above the bulk plasmon frequency. Furthermore, we find a surface plasmon polariton band which admits the Voigt and Faraday features simultaneously. Also, we show that the waveguide thickness and the chemical potential of the Weyl semimetals can be used as a fine-tuning parameters in these structures. Our findings may be employed in optical devices which exploit the unidirectional surface plasmon propagation features.
Summary
We studied the risk for hip fracture before and after total knee replacement (TKR) in the entire population in Sweden. Women and men had a low risk for hip fracture before TKR but an ...increased risk the first year after TKR.
Purpose
It is known that osteoarthritis is associated with high bone mass. We therefore studied the risk of hip fracture before and after total knee replacement (TKR), risk of different hip fracture types, and risk subdivided in genders and age groups.
Methods
We followed the total Swedish population born between 1902 and 1952 (
n
= 4,258,934) during the period 1987–2002 and identified all patients with TKR due to primary OA (
n
= 39,291), and all patients with hip fracture (
n
= 195,860) in the Swedish National Inpatient Register. The risk time analyses were based on Poisson regression models.
Results
The hazard ratio (HR) for hip fracture the last year before TKR was 0.86 (95% CI 0.74 to 1.00) and the first year after 1.26 (95% CI 1.11 to 1.42) compared to individuals without TKR. The HR for femoral neck fracture 0–10 years after TKR was 0.95 (95% CI 0.89 to 1.01) and for trochanteric fracture was 1.13 (95% CI 1.06 to 1.21). The HR for hip fracture in the age group 50–74 was 1.28 (95% CI 1.14 to 1.43) and in the age group 75–90 years was 0.99 (95% CI 0.94 to 1.04) 0–10 years after TKR, compared to individuals without TKR.
Conclusion
Individuals had a low risk for hip fracture before TKR but an increased risk the first year after TKR. The risk in individuals below age 75 years and for trochanteric fractures was increased after TKR. Possible explanations include changed knee kinematics after a TKR, physical activity level, fall risk, and other unknown factors.
The peculiar topological properties of Weyl semimetals (WSMs) lead to unusual and unique optical properties. We investigate novel features of surface plasmon polaritons (SPPs) in a slot waveguide ...comprised of two semi-infinite WSMs with different symmetries, one with broken time reversal symmetry (TRS) and the other with broken inversion symmetry. We consider Voigt and Faraday configurations for SPPs at the interface of the WSM with broken TRS. We demonstrate that in the Voigt configuration this structure supports unidirectional SPP modes above the bulk plasmon frequency while it shows a non-reciprocal bidirectional dispersion for surface plasmon polaritons below the bulk plasmon frequency. In particular, we show that the chiral nature of the SPPs can be tuned by the topological properties and chemical potential of the WSMs. Moreover, in the Faraday configuration we find a tunable gap in the SPP dispersion. The studied structures possessing these exotic features may be employed as one of the building blocks of the chiral optoelectronic devices.
Little is known about the role of the genitourinary and gastrointestinal microbiota in the pathogenesis of male infertility.
To compare the taxonomic and functional profiles of the gut, semen, and ...urine microbiomes of infertile and fertile men.
We prospectively enrolled 25 men with primary idiopathic infertility and 12 healthy men with proven paternity, and we collected rectal swabs, semen samples, midstream urine specimens, and experimental controls.
We performed comprehensive semen analysis, 16S rRNA sequencing for quantitative high-resolution taxonomy, and shotgun metagenomics with a median of 140 million reads per sample for functional metabolic pathway profiling.
We identified a diverse semen microbiome with modest similarity to the urinary microbiome. Infertile men harbored increased seminal α-diversity and distinct β-diversity, increased seminal Aerococcus, and decreased rectal Anaerococcus. Prevotella abundance was inversely associated with sperm concentration, and Pseudomonas was directly associated with total motile sperm count. Vasectomy appeared to alter the seminal microbiome, suggesting a testicular or epididymal contribution. Anaerobes were highly over-represented in the semen of infertile men with a varicocele, but oxidative stress and leukocytospermia were associated with only subtle differences. Metagenomics data identified significant alterations in the S-adenosyl-L-methionine cycle, which may play a multifaceted role in the pathogenesis of infertility via DNA methylation, oxidative stress, and/or polyamine synthesis.
This pilot study represents the first comprehensive investigation into the microbiome in male infertility. These findings provide the foundation for future investigations to explore causality and identify novel microbiome-based diagnostics and therapeutics for men with this complex and emotionally devastating disease.
We explored the resident populations of bacteria living in the gut, semen, and urine of infertile and fertile men. We found several important bacterial and metabolic pathway differences with the potential to aid in diagnosing and treating male infertility in the future.
We explored the resident populations of bacteria living in the gut, semen, and urine of infertile and fertile men. We found several important bacterial and metabolic pathway differences with the potential to aid in diagnosing and treating male infertility in the future.
Between 1993 and 1998, the Hengill volcanic region in southwest Iceland was subject to a significant volcano-tectonic event which caused a total of 8 cm uplift and induced >90 thousand earthquakes, ...most of magnitude smaller than 2 ML and a small intrusion has been proposed as its cause. In this paper, we study fault activation around the uplift center to analyze whether the Coulomb stress change induced by such an intrusion would cause the observed crustal response. The locations of a subset of 12,000 micro-earthquakes are significantly improved by a double-difference relocation algorithm and the use of cross-correlation of waveforms to refine phase arrival times. The vast majority of seismic activity is scattered, but twenty-five (25) rectangular prisms, consisting of 11 to 363 earthquakes and 200 to 3000 m long, were identified and are interpreted as faults. Most of these faults are sub-vertical (within 5° from vertical) and only two faults dip at angles of 62° and 65°, respectively. Focal mechanism analysis of individual events was applied to estimate slip direction on these faults. Simulation of the Coulomb stress changes reveals that the stress changes would have been able to induce the observed fault movement on 22 of 25 faults. Discrepancies on the remaining faults are likely caused by uncertainties in the rake directions. Our results emphasize that the seismicity caused by a volume change in the crust is controlled by the interplay between the local stress field and the induced stresses.
•Relative relocations of earhtquakes in Hengill, SW-Iceland•Joint interpretation of locations and focal mechanisms to map faults•Twenty-three of twenty-five faults are near-vertical strike-slip faults•Modeled Coulomb stress changes account for movement on faults
This paper presents a thorough review of transmitarray devices particularly aiming antenna beamsteering, gathering some of the most relevant solutions published by the scientific community in the ...field. First, the background for realizing 1-D and 2-D antenna beamsteering with a transmitarray is introduced. Subsequently, several examples of unit-cells for transmitarray implementation and complete transmitarray designs presented in the literature are outlined. Each solution is analyzed in detail, identifying the nature of its layout, e.g., based on microstrip patches, frequency selective surfaces (FSS), or metamaterials (MMs), and the method employed to enable electronic reconfigurability, e.g., p-i-n diodes, varactor diodes, or microelectromechanical systems (MEMS). In addition, some models with the capability of controlling the wavefront polarization modes are also included herein since these are the base of hybrid transmitarrays, i.e., transmitarray with both electronic beamsteering and polarization control. Finally, all the models are compared against each other in order to highlight their benefits and limitations, summarizing their main characteristics, such as the frequency of operation and bandwidth, insertion loss, physical dimensions, and maximum beamsteering range, when available.
Several empirical correlations are available to estimate the volumetric mass transfer coefficient and effective interfacial area for bubble column reactors. But these empirical correlations are ...applicable over the range of experimental conditions. By considering the broad range of parameters in a database, data-driven machine-learning methods can be used to correlate the design parameters. In this work, a generalized machine learning-based methodology is presented to calculate the volumetric mass transfer coefficient and effective interfacial area with independent parameters. Machine learning methods such as support vector regression (SVR), random forest (RF), extra trees (EXT), and artificial neural networks (ANN) have been used. An extensive set of experimental data points (1245 data points for volumetric mass transfer coefficient and 526 for interfacial area) have been extracted from the literature. The predictors, column diameter, column height, sparger design, sparger location, percentage free area, superficial gas and liquid velocity, pressure, temperature, density of gas and liquid, viscosity of gas and liquid, and diffusion coefficient, have been used to calculate design parameters. The performance of the machine learning methods has been compared using statistical parameters: mean absolute percentage error (MAPE), mean square error (MSE), and determination coefficient/prediction accuracy (R-square). Statistical analysis shows that the predictive ability of machine learning methods is better than that of traditional regression methods. The extra tree predictions were accurate compared to other methods, and the statistical parameters by extra trees were found to be the best among the methods. For the volumetric mass transfer coefficient, R-square = 0.98, MSE = 2 × 10–4, and MAPE = 15.67, and for the effective interfacial area, R-square = 0.98 and MAPE = 12.04.
The rapid increase in energy demand in the city of Reykjavik has posed the need for an additional supply of deep geothermal energy. The deep-hydraulic (re-)stimulation of well RV-43 on the peninsula ...of Geldinganes (north of Reykjavik) is an essential component of the plan implemented by Reykjavik Energy to meet this energy target. Hydraulic stimulation is often associated with fluid-induced seismicity, most of which is not felt on the surface but which, in rare cases, can be a nuisance to the population and even damage the nearby building stock. This study presents a first-of-its-kind pre-drilling probabilistic induced seismic hazard and risk analysis for the site of interest. Specifically, we provide probabilistic estimates of peak ground acceleration, European microseismicity intensity, probability of light damage (damage risk), and individual risk. The results of the risk assessment indicate that the individual risk within a radius of 2 km around the injection point is below 0.1 micromorts, and damage risk is below 10−2, for the total duration of the project. However, these results are affected by several orders of magnitude of variability due to the deep uncertainties present at all levels of the analysis, indicating a critical need in updating this risk assessment with in situ data collected during the stimulation. Therefore, it is important to stress that this a priori study represents a baseline model and starting point to be updated and refined after the start of the project.
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