Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Survey of Extra-Low Frequency and Very-Low Frequency Magnetic Fields in
  Cell Culture Incubators   A typical cell culture CO2 incubator was probed in detail to document the
pattern of 60-Hz magnetic fields (MFs) inside the unit, as well as the ability
of the incubator to attenuate environmental MFs. Subsequently, a survey of 46
cell culture incubators was performed. The survey measured MFs outside and
inside the incubators, the frequency spectrum between 5 and 2000 Hz, and
variations over time of the 60-Hz MF. Our measurements show an uneven spatial
distribution, reflecting electronic and electrical components hidden within the
walls. Attenuation of environmental MFs varied between 18 % and 33 %,
signalling easy penetration into the units. MF levels, frequency spectra and
variations over time were very different from one unit to the next. All 46
incubators surveyed had an average field greater than 0.2 microT; among them,
39 (85 %) had an average field greater than 1 microT. There is substantial work
to be done in improving control over the MF environment of in vitro experiments
in bio-medicine, particularly if they involve cancer cells.

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The categories of this paper are: math-ph
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The categories of this paper are: nlin
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: atom-ph
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The categories of this paper are: solv-int
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The categories of this paper are: hep-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: cond-mat
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The categories of this paper are: adap-org
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The categories of this paper are: q-alg
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The categories of this paper are: quant-ph
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The categories of this paper are: math
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-th