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Comment on: The Vitamin D⁻Folate Hypothesis as an Evolutionary Model for Skin Pigmentation: An Update and Integration of Current Ideas, Nutrients 2018, 10, 554.
In response to a recent article by Jones et al. (Nutrients 10: 554⁻568, 2018) [1], we agree that three distinctive features evolved in Homo erectus prior to the emergence of modern humans.[...]
QR Hits a Homerun: Landmine-Detection Systems Based on Quadrupole Resonance Technology Show Progress
This study explains how quadrupole resonance technology in mine-detection systems improves with use and drastically reduces false alarms and deminer fatigue
Radiative cooling in collisionally and photo ionized plasmas
We discuss recent improvements in the calculation of the radiative cooling in
both collisionally and photo ionized plasmas. We are extending the spectral
simulation code Cloudy so that as much as possible of the underlying atomic
data is taken from external databases, some created by others, some developed
by the Cloudy team. This paper focuses on recent changes in the treatment of
many stages of ionization of iron, and discusses its extensions to other
elements. The H-like and He-like ions are treated in the iso-electronic
approach described previously. Fe II is a special case treated with a large
model atom. Here we focus on Fe III through Fe XXIV, ions which are important
contributors to the radiative cooling of hot, 1e5 to 1e7 K, plasmas and for
X-ray spectroscopy. We use the Chianti atomic database to greatly expand the
number of transitions in the cooling function. Chianti only includes lines that
have atomic data computed by sophisticated methods. This limits the line list
to lower excitation, longer wavelength, transitions. We had previously included
lines from the Opacity Project database, which tends to include higher energy,
shorter wavelength, transitions. These were combined with various forms of the
g-bar approximation, a highly approximate method of estimating collision rates.
For several iron ions the two databases are almost entirely complementary. We
adopt a hybrid approach in which we use Chianti where possible, supplemented by
lines from the Opacity Project for shorter wavelength transitions. The total
cooling including the lightest thirty elements differs significantly from some
previous calculations
Quantum Magnetics Targets Landmine Explosives Using Quadrupole Resonance
San Diego-based Quantum Magnetics did not intend to develop the world’s best landmine detection technology, but it just might turn out that way. For the past five years, the company has been working to develop landmine detection technology that would be so specific and effective that it would minimize false alarms, thus saving lives and limbs of U.S. soldiers, citizens and landmine sweepers alike. Although Quantum Magnetics is also developing other security-related technologies for applications such as bomb, drug and concealed-weapon detection, it has continued to keep its core objective on course, and its scientists continue to concentrate on solving the most important ingredient of landmine detection—identifying buried landmine explosives used in mines quickly and with few false alarms. By targeting the specific molecules of explosives (such as RDX, tetryl, PETN, and the hardest to detect, TNT), Quantum Magnetics believes its sensors alone, or in combination with other detection devices, will be instrumental in removing the estimated 60 million to 110 million landmines abandoned throughout the world
New starches: Physicochemical properties of sweetsop (Annona squamosa) and soursop (Annona muricata) starches
Starch from the fruits of sweetsop (Anonna squamosa) and soursop (Anonna muricata) were isolated and purified and the fat, ash, phosphorus and protein contents measured. The amount of amylose present was determined spectrophotometrically and found to be very similar ( 19%) for both starches. Scanning electron microscopy showed very small indented and spherical granules from both with an average granule size of 4.84 μm and 4.72 μm, respectively. The physicochemical properties, namely the swelling power, solubility, pasting characteristics, paste clarity and freeze–thaw stability were studied to assess the functionality of the starch pastes as hydrocolloids. The sweetsop starch showed higher swelling power and solubility compared to soursop starch and had a lower gelatinization temperature indicating a weaker granular structure. Sweetsop starch exhibited a lower pasting temperature, higher viscosity peak, higher viscosity breakdown and lower setback, higher paste clarity and freeze–thaw stability compared to soursop starch. The low gelatinization temperature and high freeze thaw stability of sweetsop starch are comparable to that of waxy corn. The properties of sweetsop indicate that it has potential for application as a thickener in frozen foods
The Schistosoma mansoni Cytochrome P450 (CYP3050A1) Is Essential for Worm Survival and Egg Development.
Schistosomiasis affects millions of people in developing countries and is responsible for more than 200,000 deaths annually. Because of toxicity and limited spectrum of activity of alternatives, there is effectively only one drug, praziquantel, available for its treatment. Recent data suggest that drug resistance could soon be a problem. There is therefore the need to identify new drug targets and develop drugs for the treatment of schistosomiasis. Analysis of the Schistosoma mansoni genome sequence for proteins involved in detoxification processes found that it encodes a single cytochrome P450 (CYP450) gene. Here we report that the 1452 bp open reading frame has a characteristic heme-binding region in its catalytic domain with a conserved heme ligating cysteine, a hydrophobic leader sequence present as the membrane interacting region, and overall structural conservation. The highest sequence identity to human CYP450s is 22%. Double stranded RNA (dsRNA) silencing of S. mansoni (Sm)CYP450 in schistosomula results in worm death. Treating larval or adult worms with antifungal azole CYP450 inhibitors results in worm death at low micromolar concentrations. In addition, combinations of SmCYP450-specific dsRNA and miconazole show additive schistosomicidal effects supporting the hypothesis that SmCYP450 is the target of miconazole. Treatment of developing S. mansoni eggs with miconazole results in a dose dependent arrest in embryonic development. Our results indicate that SmCYP450 is essential for worm survival and egg development and validates it as a novel drug target. Preliminary structure-activity relationship suggests that the 1-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)ethan-1-ol moiety of miconazole is necessary for activity and that miconazole activity and selectivity could be improved by rational drug design
Emerging Contaminants in Virginia
This Article summarizes the rise of emerging contaminants in waterways in Virginia and nationwide, and how they affect ecological and human health. First, we review the scientific discovery of chemicals that alter hormone systems, reproductive and developmental processes and how these were discovered in waterways. We go on to explain the current state of emerging contaminant regulations, noting that few states have a clear understanding of what chemicals are discharged into surface waters. The Environmental Protection Agency (EPA) has no national effort in this area, despite congressional interest and action. Finally, we make recommendations for future emerging contaminant control and monitoring
4-(Benzylideneamino)benzenesulfonamide
The title compound, C13H12N2O2S, formed by Schiff base condensation of benzaldehyde with sulfanilamide, crystallizes as discrete molecular species linked by N—H⋯N and N—H⋯O hydrogen bonds between the sulfamide nitrogen H atoms and the azamethine N and one sulfamide O atom, respectively, forming a two-dimensional array in the bc plane. The azamethine group is rotated slightly out of the benzaldehyde benzene plane [C—C—C—N torsion angle = 8.1 (3)°], while the dihedral angle between the two benzene rings is 30.0 (1)°
Primary Beam Shape Calibration from Mosaicked, Interferometric Observations
Image quality in mosaicked observations from interferometric radio telescopes
is strongly dependent on the accuracy with which the antenna primary beam is
calibrated. The next generation of radio telescope arrays such as the Allen
Telescope Array (ATA) and the Square Kilometer Array (SKA) have key science
goals that involve making large mosaicked observations filled with bright point
sources. We present a new method for calibrating the shape of the telescope's
mean primary beam that uses the multiple redundant observations of these bright
sources in the mosaic. The method has an analytical solution for simple
Gaussian beam shapes but can also be applied to more complex beam shapes
through minimization. One major benefit of this simple, conceptually
clean method is that it makes use of the science data for calibration purposes,
thus saving telescope time and improving accuracy through simultaneous
calibration and observation. We apply the method both to 1.43 GHz data taken
during the ATA Twenty Centimeter Survey (ATATS) and to 3.14 GHz data taken
during the ATA's Pi Gigahertz Sky Survey (PiGSS). We find that the beam's
calculated full width at half maximum (FWHM) values are consistent with the
theoretical values, the values measured by several independent methods, and the
values from the simulation we use to demonstrate the effectiveness of our
method on data from future telescopes such as the expanded ATA and the SKA.
These results are preliminary, and can be expanded upon by fitting more complex
beam shapes. We also investigate, by way of a simulation, the dependence of the
accuracy of the telescope's FWHM on antenna number. We find that the
uncertainty returned by our fitting method is inversely proportional to the
number of antennas in the array.Comment: Accepted by PASP. 8 pages, 8 figure
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