64 research outputs found
Assessing the impact of pregnancy and birth factors on the maternal and infant microbiota
Background: The microbiota acquired at birth is known to play an intimate role in later life health and disease and has been shown to be affected by the mode of birth. There has been recent interest in microbiota correction by maternal vaginal seeding in Cesarean section-born infants; however, the safety of this practice has been debated. The aim of this study was to assess how other factors, such as timing of sampling, maternal obesity, vaginal Group B Streptococcus colonization (GBS), and antibiotic exposure, affect the maternal and infant microbiota.
Methods: Maternal vaginal and saliva samples were collected at three time periods: 35-37 weeks gestation (prenatal), within 24-36 hours after birth (birth), and at ~6 weeks postpartum. Infant saliva and stool samples were collected at ~6 weeks postpartum. 16S rRNA amplicon sequencing was utilized to assess the taxonomic and inferred functional compositions of the bacterial communities from both mothers and infants.
Results: Samples from 36 mothers and 32 infants were obtained. Gestational age, breastfeeding, mode of birth, and gravidity were associated with taxonomic alterations in the infant samples, while obesity, antibiotic use, and GBS status were not. Maternal samples were predominantly affected by time, whereby significant alterations including increased microbial diversity were seen at birth and persisted to 6 weeks postpartum.
Conclusion: This study provides information on the relationship between health and delivery factors and changes in vaginal and infant microbiota. These results may better direct clinicians and mothers in optimizing the infant microbiota towards health during infancy and later life
Effect of the Output of the System in Signal Detection
We analyze the consequences that the choice of the output of the system has
in the efficiency of signal detection. It is shown that the signal and the
signal-to-noise ratio (SNR), used to characterize the phenomenon of stochastic
resonance, strongly depend on the form of the output. In particular, the SNR
may be enhanced for an adequate output.Comment: 4 pages, RevTex, 6 PostScript figure
The association between alcohol outlet accessibility and adverse birth outcomes: A retrospective cohort study
BACKGROUND:Alcohol outlet accessibility is positively associated with alcohol consumption, although this relationship has not been thoroughly examined in pregnant women. The present study examines the relationship between proximity and density of alcohol outlets and risk for low birth weight (LBW: \u3c2,500 grams) and preterm birth (PTB: \u3c37 weeks gestational age), and is the first Canadian study to investigate this association.
METHODS:Maternal accessibility to alcohol outlets was specified using a gravity-type measure of accessibility, which provides the amount of accessibility that a given household has to liquor stores within 30-minutes of their home. All singleton newborns without congenital anomalies that were born between February 2009 and February 2014 at London Health Sciences Centre in London, Ontario, were included in this cohort.
RESULTS:The sample consisted of 25,734 live births, of which 5.8% were LBW and 7.6% were PTB. Only 2.0% of women reported alcohol use during pregnancy. Alcohol outlet gravity was positively correlated with the percentage of mothers living in poverty (rs = 0.33, p \u3c 0.001) and in single-parent families (rs = 0.39, p \u3c 0.001), and who self-identify as visible minorities (rs = 0.45, p \u3c 0.001). Alcohol outlet gravity increased the odds that mothers drank alcohol during pregnancy (OR 1.05; 95% CI: 1.02, 1.07), although the association was weak. Furthermore, alcohol outlet gravity did not increase the likelihood of a LBW or PTB infant.
CONCLUSIONS:Women with high accessibility to alcohol outlets are more likely to consume alcohol during pregnancy, but greater alcohol outlet accessibility does not translate into poor birth outcomes
Perceived Object Stability Depends on Multisensory Estimates of Gravity
BACKGROUND: How does the brain estimate object stability? Objects fall over when the gravity-projected centre-of-mass lies outside the point or area of support. To estimate an object's stability visually, the brain must integrate information across the shape and compare its orientation to gravity. When observers lie on their sides, gravity is perceived as tilted toward body orientation, consistent with a representation of gravity derived from multisensory information. We exploited this to test whether vestibular and kinesthetic information affect this visual task or whether the brain estimates object stability solely from visual information. METHODOLOGY/PRINCIPAL FINDINGS: In three body orientations, participants viewed images of objects close to a table edge. We measured the critical angle at which each object appeared equally likely to fall over or right itself. Perceived gravity was measured using the subjective visual vertical. The results show that the perceived critical angle was significantly biased in the same direction as the subjective visual vertical (i.e., towards the multisensory estimate of gravity). CONCLUSIONS/SIGNIFICANCE: Our results rule out a general explanation that the brain depends solely on visual heuristics and assumptions about object stability. Instead, they suggest that multisensory estimates of gravity govern the perceived stability of objects, resulting in objects appearing more stable than they are when the head is tilted in the same direction in which they fall
The Nordic Expert Group for Criteria Documentation of Health Risks from Chemicals and The Dutch Expert Committee on Occupational Standards : 126. 1,2,3-Benzotriazole
Benzotriazole is an odourless, white to tannish crystalline powder. It is sparingly soluble in water and soluble in a number of organic solvents. It has a low vapour pressure, and it is therefore likely to occur as dust at the workplace. When finely divided and mixed with air, dust explosions may occur. Benzotriazole is an industrial compound primarily used as a corrosion inhibitor, as a plastic stabiliser, and as a chemical intermediate. There is very little information found with respect to the toxicokinetics of benzotriazole. Based on experimental animal data with benzotriazole of unknown purity and limited human data, it is concluded that benzotriazole is slightly irritating to the eyes and, at most, slightly irritating to the skin Benzotriazole is considered not to be a skin sensitiser. In the carcinogenicity studies, higher incidences of : mostly benign : tumours in some organs were observed in treated than in concurrent control animals. These tumours had mostly higher incidences in the low-dose than in the high-dose group, and occurred at fairly high rates in historical controls. The LOAELs were set at 295 and 1455 mg/kg bw/day in rats and mice, respectively. In view of the inconclusive evidence for carcinogenic potential of benzotriazole in rodents and the mutagenic effects of benzotriazole in bacterial systems along with the absence of mutagenic and genotoxic effects in vitro in mammalian cells and in vivo in experimental animals, the data base is too poor to justify a conclusion regarding genotoxicity and carcinogenicity of this chemical.Bensotriazol är ett luktlöst, vitt till ljusbrunt kristallint pulver. Det är svårlösligt i vatten men lösligt i många organiska lösningsmedel. Ämnet har lågt ångtryck och förekommer därför troligen som damm i arbetsmiljön. När det finfördelas och blandas med luft finns risk för dammexplosioner. Bensotriazol är en industrikemikalie som framför allt används för att förhindra korrosion, som stabiliserare i plaster och som kemisk intermediär. Informationen om upptag och omsättning av bensotriazol är mycket sparsam. Baserat på djurförsök med bensotriazol av okänd renhet och på begränsade humandata får bensotriazol anses vara svagt irriterande på ögon, och som mest, något irriterande på hud. Bensotriazol anses inte vara hudsensibiliserande. I cancerstudier observerades en högre incidens av : huvudsakligen godartade -tumörer i vissa organ hos de behandlade djuren jämfört med de jämsides löpande kontrolldjuren. Tumörerna hade vanligen en högre incidens i lågdos- än i högdosgruppen, och förekom med relativt hög frekvens hos de historiska kontrollerna. LOAEL-värdena var 295 och 1455 mg/kg kroppsvikt/dag hos råtta respektive mus. På grund av icke-konklusiva data vad gäller bensotriazols carcinogena potential hos gnagare samt ämnets mutagena effekt i bakteriesystem i kombination med frånvaron av mutagena och genotoxiska effekter in vitro i däggdjursceller och in vivo hos försöksdjur kan inga slutsatser dras vad gäller bensotriazols genotoxicitet och carcinogenicitet. Nyckelord: bensotriazol, hygieniskt gränsvärde, irritation, riskbedömning, toxikolog
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Processes, Terms and Cycles: Steps on the Road to Infinity, Essays Dedicated to Klop, J.W., on the Occasion of His 60th Birthday
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