We discuss the design and performance of a very sensitive low-field magnetometer based on the detection of free spin precession of gaseous, nuclear polarized
3
He or
129
Xe samples with a SQUID as ...magnetic flux detector. The device will be employed to control fluctuating magnetic fields and gradients in a new experiment searching for a permanent electric dipole moment of the neutron. Furthermore, with the detection of the free precession of co-located
3
He/
129
Xe nuclear spins it can be used as ultra-sensitive probe for non-magnetic spin interactions, since the magnetic dipole interaction (Zeeman-term) drops out. Characteristic spin precession times T
2
*
of up to 60 h were measured. The achieved signal-to-noise ratio of more than 5000:1 leads to an expected sensitivity level (Cramer-Rao lower bound) of δB≈1 fT after an integration time of 220 s and of δB≈10
-4
fT after one day. By means of a co-located
3
He/
129
Xe magnetometer, noise sources inherent in the magnetometer could be investigated, showing that CRLB is fulfilled, at least down to δB≈10
-2
fT. The reason for such a high sensitivity is that free precessing
3
He (
129
Xe) nuclear spins are almost completely decoupled from the environment. Therefore, this type of magnetometer is particularly attractive for precision field measurements where long-term stability is required.
We discuss the design and performance of a very sensitive low-field magnetometer based on the detection of free spin precession of gaseous, nuclear polarized 3He or 129Xe samples with a SQUID as ...magnetic flux detector. The device will be employed to control fluctuating magnetic fields and gradients in a new experiment searching for a permanent electric dipole moment of the neutron as well as in a new type of 3He/129Xe clock comparison experiment which should be sensitive to a sidereal variation of the relative spin precession frequency. Characteristic spin precession times T_2 of up to 60h could be measured. In combination with a signal-to-noise ratio of > 5000:1, this leads to a sensitivity level of deltaB= 1fT after an integration time of 220s and to deltaB= 10^(-4)fT after one day. Even in that sensitivity range, the magnetometer performance is statistically limited, and noise sources inherent to the magnetometer are not limiting. The reason is that free precessing 3He (129Xe) nuclear spins are almost completely decoupled from the environment. That makes this type of magnetometer in particular attractive for precision field measurements where a long-term stability is required.
Purpose
Despite the health benefits of full breastfeeding for both infants and mothers, less than 50% of mothers in Germany practice this method for at least 4 months after childbirth. Because of the ...growing importance of health literacy to improve public health, we investigated the role of maternal health literacy in breastfeeding behavior.
Methods
We analyzed the data of 1172 mother–child dyads of the KUNO-Kids health study of the University Children’s and Maternity Hospital Regensburg. Maternal health literacy was assessed with the HLS-EU-Q47 questionnaire (sub-index health care) up to 48 h after childbirth. Outcome was analyzed 6 months after childbirth and categorized into full breastfeeding for less than 4 months or for at least 4 months. The association between breastfeeding and maternal health literacy was calculated with univariable and multivariable logistic regression analyses.
Results
38.8% of mothers showed inadequate or limited health literacy. 75.9% of mothers had fully breastfed their child for at least 4 months. Univariable logistic regression analysis showed that health literacy and full breastfeeding for at least 4 months were not associated (OR = 0.995 CI 0.977–1.015,
p
= 0.60). After adjusting for all potentially confounding variables with a significant association (
p
≤ 0.05) on both health literacy and breastfeeding, the multivariable model showed no association between health literacy and breastfeeding (OR = 0.984 CI 0.963–1.007,
p
= 0.170).
Conclusion
Surprisingly, we found no association between health literacy and breastfeeding behavior in our study. Therefore, future research with comparable measurements of health literacy and breastfeeding is required to validate this result and to identify reasons for early breastfeeding cessation.
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