Cross-sectional studies have reported an association between lead (Pb) levels in bone and delinquent behavior in later childhood and adolescence. This is the first prospective longitudinal study of ...Pb and child development to address this question with comprehensive assessments of toxicant exposure and other developmental cofactors. A prospective longitudinal birth cohort of 195 urban, inner-city adolescents recruited between 1979 and 1985 was examined. Relationships between prenatal and postnatal exposure to Pb (serial blood Pb determinations) and antisocial and delinquent behaviors (self- and parental reports) were examined. Prenatal exposure to Pb was significantly associated with a covariate-adjusted increase in the frequency of parent-reported delinquent and antisocial behaviors, while prenatal and postnatal exposure to Pb was significantly associated with a covariate-adjusted increase in frequency of self-reported delinquent and antisocial behaviors, including marijuana use. Use of marijuana itself by Cincinnati Lead Study (CLS) teens was strongly associated with all measures of delinquent and antisocial behavior. This prospective longitudinal study confirmed earlier clinical observations and recent retrospective studies that have linked Pb exposure with antisocial behavior in children and adolescents. Both prenatal and postnatal exposure to Pb were associated with reported antisocial acts and may play a measurable role in the epigenesis of behavioral problems independent of the other social and biomedical cofactors assessed in this study.
Human studies suggest that high-fat diets (HFDs) increase the risk of breast cancer. The 7,12-dimethylbenzaanthracene (DMBA)-induced mammary carcinogenesis rat model is commonly used to evaluate the ...effects of lifestyle factors such as HFD on mammary tumor risk. Past studies focused primarily on the effects of continuous maternal exposure on the risk of offspring at the end of puberty (PND50). We assessed the effects of prenatal HFD exposure on cancer susceptibility in prepubertal mammary glands and identified key gene networks associated with such disruption. During pregnancy, dams were fed AIN-93G-based diets with isocaloric high olive oil, butterfat or safflower oil. The control group received AIN-93G. Female offspring were treated with DMBA on PND21. However, a significant increase in tumor volume and a trend of shortened tumor latency were observed in rats with HFD exposure against the controls (P=.048 and P=.067, respectively). Large-volume tumors harbored carcinoma in situ. Transcriptome profiling identified 43 differentially expressed genes in the mammary glands of the HFBUTTER group as compared with control. Rapid hormone signaling was the most dysregulated pathway. The diet also induced aberrant expression of Dnmt3a, Mbd1 and Mbd3, consistent with potential epigenetic disruption. Collectively, these findings provide the first evidence supporting susceptibility of prepubertal mammary glands to DMBA-induced tumorigenesis that can be modulated by dietary fat that involves aberrant gene expression and likely epigenetic dysregulation.
With the evidence for massive neutrinos from recent
ν-oscillation experiments, one of the most fundamental tasks of particle physics over the next years will be the determination of the absolute mass ...scale of neutrinos, which has crucial implications for cosmology, astrophysics and particle physics. The
KArlsruhe
TRItium
Neutrino (KATRIN) experiment is the next-generation direct neutrino mass experiment with a sensitivity to sub-eV
ν-masses. It combines an ultra-luminous windowless gaseous molecular tritium source with a high resolution electrostatic retarding spectrometer (MAC-E filter) to measure the spectral shape of
β-decay electrons close to the endpoint at 18.6 keV with unprecedented precision. If no neutrino mass signal is found, the KATRIN sensitivity after 3 years of measurements is
m
ν
<
0.2
eV
/
c
2
(90 % C.L.); a
ν-mass signal of
m
ν
=
0.35
eV
/
c
2
can be measured with 5
σ evidence.
One hundred and ninety-five participants in the Cincinnati Lead Study were neuropsychologically evaluated in mid-adolescence. The neuropsychological measures yielded five factors labeled Memory, ...Learning/IQ, Attention, Visuoconstruction, and Fine-Motor. Prenatal, Average Childhood, and 78 month blood lead (PbB) levels were used in a series of multiple regression analyses. Following rigorous covariate pretesting and adjustment, a significant main effect of 78 month PbB on the Fine-Motor factor was found (p <.004). Significant interactions were also found between gender and lead exposure parameters for both Attention and Visuoconstruction indicating heightened risk in males. Finally, a trend toward significance was found for the PbB x SES interaction for Learning/IQ, consistent with previous evidence of increased educational and cognitive vulnerability for youth from more disadvantaged backgrounds. These results provide new evidence from the longest continuing prospective study of the remote effects of early lead exposure. They indicate the presence of selective neuropsychological effects in this population, and also that males and females are not uniformly affected. These results also underscore the complexity of models of neurobehavioral development, and the modest predictive power of any single determinant.
In this work, we present the first spectroscopic measurements of conversion electrons originating from the decay of metastable gaseous 83mKr with the Karlsruhe Tritium Neutrino (KATRIN) experiment. ...The obtained results represent one of the major commissioning milestones for the subsequent direct neutrino mass measurement with KATRIN. The successful campaign demonstrates the functionalities of the KATRIN beamline. Precise measurement of the narrow K-32, L3-32, and N2,3-32 conversion electron lines allowed to verify the eV-scale energy resolution of the KATRIN main spectrometer necessary for competitive measurement of the absolute neutrino mass scale.
The gas-flow reduction factor of the second forward Differential Pumping Section (DPS2-F) for the KATRIN experiment was determined using a dedicated vacuum-measurement setup and by detailed ...molecular-flow simulation of the DPS2-F beam tube and of the measurement apparatus. In the measurement, non-radioactive test gases deuterium, helium, neon, argon and krypton were used, the input gas flow was provided by a commercial mass-flow controller, and the output flow was measured using a residual gas analyzer, in order to distinguish it from the outgassing background. The measured reduction factor with the empty beam tube at room temperature for gases with mass 4 is 1.8(4) × 104, which is in excellent agreement with the simulated value of 1.6 × 104. The simulated reduction factor for tritium, based on the interpolated value for the capture factor at the turbo-molecular pump inlet flange is 2.5 × 104. The difference with respect to the design value of 1 × 105 is due to the modifications in the beam tube geometry since the initial design, and can be partly recovered by reduction of the effective beam tube diameter.
► We measured the gas reduction factor of the differential pumping section of KATRIN. ► We calibrated and used a residual gas analyzer for mass-selective measurement. ► We used 5 different test gases to establish the mass dependence of the gas reduction. ► We used simulations to estimate the flow reduction factor for tritium. ► The estimated reduction factor for tritium is 2.5e4.
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