Alien Registration- Mikkelsen, Ole A. (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/31187/thumbnail.jp

situ particle size distributions and volume concentrations from a LISST-100 laser particle sizer and a digital floc

Abstract A LISST-100 in situ laser particle sizer was deployed together with a digital floc camera during field work in the Newark Bay area (USA) and along the Apennine margin (the Adriatic Sea, Italy). The purpose of these simultaneous deployments was to investigate how well in situ particle (floc) sizes and volume concentrations from the two different instruments compared. In the Adriatic Sea the two instruments displayed the same temporal variation, but the LISST provided lower estimates of floc size by a factor of 2-3, compared to the DFC. In the Newark Bay area, the LISST provided higher values of floc size by up to a factor of 2. When floc size was computed using only the overlapping size bins from the two instruments the discrepancy disappeared. The reason for the discrepancy in size was found to be related to several issues: First, the LISST measured particles in the 2.5-500 mm range, whereas the camera measured particles in the 135-9900 mm range, so generally the LISST should provide lower estimates of floc size, as it measures the smaller particles. Second, in the Newark Bay area scattering from particles 4500 mm generally caused the LISST to overestimate the volume of particles in its largest size bin, thereby increasing apparent floc size. Relative to the camera, the LISST generally provided estimates of total floc volume that were lower by a factor of 3. Factors that could explain this discrepancy are errors arising from the accuracy of the LISST volume conversion coefficient and image processing. Regardless of these discrepancies, the shapes of the size spectra from the instruments were similar in the regions of overlap and could be matched by multiplying with an appropriate correction coefficient. This facilitated merging of the size spectra from the LISST and the DFC, yielding size spectra in the 2.5-9900 mm range. The merged size spectra generally had one or more peaks in the coarse end of the spectrum, presumably due to the presence of flocs. The fine end (o100 mm) of the spectrum displayed a flat tail with equal concentration of particles in all size classes. Size spectra with this shape indicate that the classical Junge model for description of in situ particle size spectra is reasonable for particles smaller than 100 mm but not for larger particles. Floc fraction was computed for the merged spectra by using a diameter-to-mass conversion and found to vary between 0.34 and 0.95, within the range reported by other authors.

Light scattering by random shaped particles and consequences on measuring suspended sediments by laser diffraction

We present new observational data on small-angle light scattering properties of natural, random shaped particles, as contrasted with spherical particles. The interest in this "shape effect" on scattering arises from the need for a suitable kernel matrix for use in the laser diffraction method (LD) of particle sizing. LD is now used broadly for measuring size distribution of suspended marine particles. LD involves the measurement of small-angle forward scattering at multiple angles. This data is inverted using the kernel matrix to produce size distribution. In the absence of a suitable matrix for random shaped particles, past practice has been to use a model based on Mie theory, applicable strictly only to homogeneous spheres. The present work replaces Mie theory with empirical data. The work was motivated in part by anomalous field observations of size distribution and settling velocity distributions reported in literature. We show that a kernel matrix for random shaped particles results in improved interpretation of field multiangle scattering observations. In particular, a rising edge at the fine particle end of the size spectrum is shown to be associated with shape effects.Keywords: optical scattering\, laser diffraction\, particle siz

Epidemiology of Hyperhidrosis in Danish Blood Donors

The risk factors and disease implications of hyperhidrosis are unknown. The objectives of this retrospective cohort study were to estimate the prevalence of hyperhidrosis and to compare demographic, lifestyle, and socioeconomic parameters in blood donors with and without self-reported or hospital-diagnosed hyperhidrosis. The study included blood donors from the Danish Blood Donor Study for the period 2010–2019. Registry data were collected from Statistics Denmark. Overall, 2,794 of 30,808 blood donors (9.07%; 95% confidence interval (95% CI) 8.75–9.40) had self-reported hyperhidrosis and 284 of 122,225 (0.23%; 95% CI 0.21–0.26) had hospital-diagnosed hyperhidrosis. Self-reported hyperhidrosis was associated with smoking (odds ratio (OR) 1.17; 95% CI 1.05– 1.31), overweight (OR 1.72; 95% CI 1.58–1.87), “unemployed” (OR 1.60; 95% CI 1.24–2.08), “short education” (OR 0.76; 95% CI 0.64–0.90), and lower income (beta-coefficient –26,121; 95% CI –37,931, –14,311). Hospital-diagnosed hyperhidrosis did not differ from controls. Thus, self-reported hyperhidrosis was associated with potential hyperhidrosis risk factors (smoking, overweight) and disease implications (unemployment, low education level and income)

Genome-wide association meta-analysis identifies five loci associated with postpartum hemorrhage

Bleeding in early pregnancy and postpartum hemorrhage (PPH) bear substantial risks, with the former closely associated with pregnancy loss and the latter being the foremost cause of maternal death, underscoring the severe impact on maternal–fetal health. We identified five genetic loci linked to PPH in a meta-analysis. Functional annotation analysis indicated candidate genes HAND2, TBX3 and RAP2C/FRMD7 at three loci and showed that at each locus, associated variants were located within binding sites for progesterone receptors. There were strong genetic correlations with birth weight, gestational duration and uterine fibroids. Bleeding in early pregnancy yielded no genome-wide association signals but showed strong genetic correlation with various human traits, suggesting a potentially complex, polygenic etiology. Our results suggest that PPH is related to progesterone signaling dysregulation, whereas early bleeding is a complex trait associated with underlying health and possibly socioeconomic status and may include genetic factors that have not yet been identified