Circadian changes and sex-related differences in fetal heart rate parameters

BACKGROUND: Previous researchers have studied circadian changes in the fetal heart rate (FHR) on small sample sizes and in a strictly controlled environment. This study was undertaken to investigate these changes during the late second and third trimesters, using a portable fetal electrocardiogram recording device (Monica AN24) in pregnant women in home and hospital environments with unrestricted mobility. METHODS: This was a prospective cohort study of 54 pregnant women with uncomplicated singleton pregnancies between 25 and 40 weeks gestation. FHR recordings were made up to 16 h at home or in the hospital setting in the United Kingdom. FHR data over 90 min periods were averaged and the day (7:00 am-11:00 pm) and night (11:00 pm-7:00 am) data from the same individual were compared. Data were examined for evidence of sex-related differences. RESULTS: During the night, there was a significant reduction in basal heart rate (bFHR) and a significant increase in short term variation (STV) and long term variation (LTV) (P < 0.05). Basal FHR decreased (P < 0.002), whereas LTV increased (P = 0.014) with advancing gestation. Male fetuses showed greater day: night variation than females regardless of gestation (P = 0.014). There was a higher bFHR in fetuses monitored during the day in hospital (P = 0.04). CONCLUSION: This study demonstrates that there are sex-, environment and time-related differences in the FHR parameters measured. These differences may need to be considered taken when interpreting FHR data

Bioaccessibility of selenium after human ingestion in relation to its chemical species and compartmentalization in maize

International audienceSelenium is a micronutrient needed by all living organisms including humans, but often present in low concentration in food with possible deficiency. From another side, at higher concentrations in soils as observed in seleniferous regions of the world, and in function of its chemical species, Se can also induce (eco)toxicity. Root Se uptake was therefore studied in function of its initial form for maize (Zea mays L.), a plant widely cultivated for human and animal food over the world. Se phytotoxicity and compartmentalization were studied in different aerial plant tissues. For the first time, Se oral human bioaccessibility after ingestion was assessed for the main Se species (SeIV and SeVI) with the BARGE ex vivo test in maize seeds (consumed by humans), and in stems and leaves consumed by animals. Corn seedlings were cultivated in hydroponic conditions supplemented with 1 mg L−1 of selenium (SeIV, SeVI, Control) for 4 months. Biomass, Se concentration, and bioaccessibility were measured on harvested plants. A reduction in plant biomass was observed under Se treatments compared to control, suggesting its phytotoxicity. This plant biomass reduction was higher for selenite species than selenate, and seed was the main affected compartment compared to control. Selenium compartmentalization study showed that for selenate species, a preferential accumulation was observed in leaves, whereas selenite translocation was very limited toward maize aerial parts, except in the seeds where selenite concentrations are generally high. Selenium oral bioaccessibility after ingestion fluctuated from 49 to 89 % according to the considered plant tissue and Se species. Whatever the tissue, selenate appeared as the most human bioaccessible form. A potential Se toxicity was highlighted for people living in seleniferous regions, this risk being enhanced by the high Se bioaccessibility

Assessing risks of soil contamination with asbestos

A methodology based on a tiered (three-step) approach was developed to enable site-specific assessment of risks of soil contamination with asbestos. Along with the presentation of this methodology, we have endeavoured to underpin the Intervention Value for soil remediation for asbestos, which was recently released by the Dutch Ministry of Housing, Spatial Planning and the Environment in its interim policy on asbestos in soil. Because risks to humans after inhalation of asbestos are the most critical, the risk assessment was based on the probability of asbestos fibre emission from soil to air, making a distinction between chrysotile and amphibole asbestos, bound and friable asbestos, and the respirable and non-respirable fraction in soil. Because the behaviour of asbestos in soil is different from the behaviour of any other soil contaminant, the CSOIL exposure model was not used. Instead, use was made of measuring results, i.e. the concentrations of asbestos in soil and air, for deriving the Intervention Value. Guidance on measurement procedures has been incorporated into tiers 2 and 3 of the methodology for determining site-specific human risks.Er is een methodiek ontwikkeld, gebaseerd op een stapsgewijze aanpak, om de locatie-specifieke risico's van bodemverontreiniging met asbest te kunnen bepalen. Bovendien is een onderbouwing gegeven voor de interventiewaarde voor asbest, welke recentelijk werd geformaliseerd door het Ministerie van VROM via het Interimbeleid voor asbest in bodem, grond en puin(granulaat). Risico's voor de mens ten gevolge van inhalatie van asbest vezels zijn het meest kritisch. Daarom is de risico-analyse gebaseerd op de mogelijkheid voor asbestvezels om in de lucht te komen, waarbij een verschil wordt gemaakt tussen chrysotiel en amfibool asbest, hechtgebonden en niet-hechtgebonden asbest en respirabele en niet-respirabele fractie in de bodem. Omdat het gedrag van asbest in de bodem verschilt van die van andere contaminant is geen gebruik gemaakt van het CSOIL blootstellingsmodel. In plaats hiervan is voor de afleiding van de interventiewaarde gebruik gemaakt van meetresultaten uit de praktijk, te weten asbestconcentraties in de bodem en de lucht. In stap 2 en 3 van de methode om het locatie-specifieke risico te bepalen is gebruik gemaakt van meetmethoden

Assessing risks of soil contamination with asbestos

Er is een methodiek ontwikkeld, gebaseerd op een stapsgewijze aanpak, om de locatie-specifieke risico's van bodemverontreiniging met asbest te kunnen bepalen. Bovendien is een onderbouwing gegeven voor de interventiewaarde voor asbest, welke recentelijk werd geformaliseerd door het Ministerie van VROM via het Interimbeleid voor asbest in bodem, grond en puin(granulaat). Risico's voor de mens ten gevolge van inhalatie van asbest vezels zijn het meest kritisch. Daarom is de risico-analyse gebaseerd op de mogelijkheid voor asbestvezels om in de lucht te komen, waarbij een verschil wordt gemaakt tussen chrysotiel en amfibool asbest, hechtgebonden en niet-hechtgebonden asbest en respirabele en niet-respirabele fractie in de bodem. Omdat het gedrag van asbest in de bodem verschilt van die van andere contaminant is geen gebruik gemaakt van het CSOIL blootstellingsmodel. In plaats hiervan is voor de afleiding van de interventiewaarde gebruik gemaakt van meetresultaten uit de praktijk, te weten asbestconcentraties in de bodem en de lucht. In stap 2 en 3 van de methode om het locatie-specifieke risico te bepalen is gebruik gemaakt van meetmethoden.A methodology based on a tiered (three-step) approach was developed to enable site-specific assessment of risks of soil contamination with asbestos. Along with the presentation of this methodology, we have endeavoured to underpin the Intervention Value for soil remediation for asbestos, which was recently released by the Dutch Ministry of Housing, Spatial Planning and the Environment in its interim policy on asbestos in soil. Because risks to humans after inhalation of asbestos are the most critical, the risk assessment was based on the probability of asbestos fibre emission from soil to air, making a distinction between chrysotile and amphibole asbestos, bound and friable asbestos, and the respirable and non-respirable fraction in soil. Because the behaviour of asbestos in soil is different from the behaviour of any other soil contaminant, the CSOIL exposure model was not used. Instead, use was made of measuring results, i.e. the concentrations of asbestos in soil and air, for deriving the Intervention Value. Guidance on measurement procedures has been incorporated into tiers 2 and 3 of the methodology for determining site-specific human risks.VROM-DGM-BW

Simultaneous analysis and design based optimization for paper path and timing design of a high-volume printer

\u3cp\u3eThe design of a high-volume printer for professional use is rather complex. The design of the paper path and the timing of sheets is frequently reengineered as the design of the printer components progresses. This paper presents an optimization model for the combined paper path and timing design problem. The paper path is an optimal physical dimensioning problem, while the timing is an open-loop optimal control problem. The coupled optimization problem is formulated as a simultaneous analysis and design (SAND) problem using a direct transcription of the optimal control problem. Benefits of the chosen formulation for industrial application are the ease of setting up the optimization model for arbitrary printer configurations, and the short computation times. Results of an industrial case are presented.\u3c/p\u3

Absolute configuration and host-guest binding of chiral porphyrin-cages by a combined chiroptical and theoretical approach.

Porphyrin cage-compounds are used as biomimetic models and substrate-selective catalysts in supramolecular chemistry. In this work we present the resolution of planar-chiral porphyrin cages and the determination of their absolute configuration by vibrational circular dichroism in combination with density functional theory calculations. The chiral porphyrin-cages form complexes with achiral and chiral viologen-guests and upon binding one of the axial enantiomorphs of the guest is bound selectively, as is indicated by induced-electronic-dichroism-spectra in combination with calculations. This host-guest binding also leads to unusual enhanced vibrational circular dichroism, which is the result of a combination of phenomena, such as rigidification of the host and guest structures, charge transfer, and coupling of specific vibration modes of the host and guest. The results offer insights in how the porphyrin cage-compounds may be used to construct a future molecular Turing machine that can write chiral information onto polymer chains

Utilizing an Earthworm Bioassay (Eisenia andrei) to Assess a South African Soil Screening Value with Regards to Effects from a Copper Manufacturing Industry

Metal contamination of soil due to industrialization has become an increasingly important problem in South Africa. This study aimed to investigate the potential impact of a copper (CuSO4·5H2O) production company on the soil environment. Bioassays using Eisenia andrei were performed to assess changes in biomass, reproduction and a biomarker, neutral red retention time, over a 28 day period. Earthworms exposed to soils from the Cu production site differed significantly (p < 0.05) from those exposed to soils 500 m and 5 km away in terms of the measured endpoints. These findings are consistent with the results from the chemical analysis which showed an elevated soil Cu content for both sites closest to the chemical production company compared to the reference site. The results confirm the importance and predictive value of using bioassays in conjunction with chemical analysis during soil quality assessments