WHAT YOU SHOULD KNOW ABOUT HOG CHOLERA

I. WHAT IS HOG CHOLERA? Hog cholera is a deadly, contagious disease that attacks swine only. The disease is caused by hog cholera virus, an agent so small (1/250,000 of an inch) that it can even pass through a fine porcelain filter. How do hogs act when they get the disease? They lie around hiding in their nest, have high fevers, are extremely weak and sick all over. They have little appetite, and often stand in a thinking attitude-motionless, tail relaxed, ears hanging limp, and the head slightly lowered as if in deep thought. Very few hogs ever recover. II. How IMPORTANT Is HOG CHOLERA? Hog cholera is the most important disease of hogs in the United States today. Farmers lose millions of dollars worth of hogs from cholera each year. And the expense of annually vaccinating millions of hogs costs even more. Many foreign markets are closed to pork from the United States because of the fear of importing hog cholera. The disease is important enough so that both state and federal governments have enacted regulatory measures and classed it as a reportable disease. In addition, the United States Congress has authorized the Secretary of Agriculture to enter into a marketing agreement with the hog cholera serum-virus industry. The original act was intended to provide that there should always be enough anti-hog cholera serum on hand to safeguard against sudden widespread outbreaks of the disease. Nevertheless, stocks of antiserum are being reduced every year

The geology and geophysics of Kuiper Belt object (486958) Arrokoth

The Cold Classical Kuiper Belt, a class of small bodies in undisturbed orbits beyond Neptune, are primitive objects preserving information about Solar System formation. The New Horizons spacecraft flew past one of these objects, the 36 km long contact binary (486958) Arrokoth (2014 MU69), in January 2019. Images from the flyby show that Arrokoth has no detectable rings, and no satellites (larger than 180 meters diameter) within a radius of 8000 km, and has a lightly-cratered smooth surface with complex geological features, unlike those on previously visited Solar System bodies. The density of impact craters indicates the surface dates from the formation of the Solar System. The two lobes of the contact binary have closely aligned poles and equators, constraining their accretion mechanism

New Data from the IS☉IS Instrument Suite on Parker Solar Probe

NASA's Parker Solar Probe (PSP) mission's first seven orbits include perihelia as close as ~11 million km (~16 solar radii), much closer to the Sun than any prior human-made object. Onboard PSP, the Integrated Science Investigation of the Sun (IS☉IS) instrument suite makes groundbreaking measurements of solar energetic particles (SEPs). Here we discuss the near-Sun energetic particle radiation environment over PSP's first two and a half years, which reveal where and how energetic particles are energized and transported. We find a great variety of energetic particle events accelerated both locally and remotely. These include stream and co-rotating interaction regions (SIRs and CIRs), “impulsive” SEP events driven by magnetic reconnection near the Sun, and events related to Coronal Mass Ejections (CMEs). These IS☉IS observations made close to the Sun provide critical information for investigating the near-Sun transport and energization of solar energetic particles, which has been difficult to resolve from prior observations. The Parker Solar Probe IS☉IS data are made public soon after receipt at Earth (which can be many months after the observations). We will also discuss how to get access to the data. © Copyright owned by the author(s) under the terms of the Creative Commons.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Time evolution of stream interaction region energetic particle spectra in the inner heliosphere

We analyze an energetic proton event associated with a stream interaction region (SIR) that was observed at Parker Solar Probe on day 320 of 2018 when the spacecraft was just 0.34 AU from the Sun. Using the Integrated Science Investigation of the Sun instrument suite, we perform a spectral analysis of the event and show how the observed spectra evolve over the course of the event. We find that the spectra from the first day of the event are much more consistent with local acceleration at a weak compression, while spectra from later on are more typical of SIR-related events in which particles accelerated at distant shocks dominate. After the first day, the spectra remain approximately constant, which indicates that the modulation of energetic particles during transit from the presumed source region is weaker than previously thought. We argue that these observations can be explained by a sub-Parker spiral magnetic field structure connecting the spacecraft to a source region in the SIR that is relatively close to the Sun. We further propose that acceleration at weak, pre-shock compressions likely plays an important role in observations of SIR-related events in the inner heliosphere and that future modelling of such events should consider acceleration all along the compression region, not just at the distant shock region. © ESO 2021.Immediate accessThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Parker Solar Probe observations of He/H abundance variations in SEP events inside 0.5 au

Aims. The Parker Solar Probe (PSP) orbit provides an opportunity to study the inner heliosphere at distances closer to the Sun than previously possible. Due to the solar minimum conditions, the initial orbits of PSP yielded only a few solar energetic particle (SEP) events for study. Recently during the fifth orbit, at distances from 0.45 to 0.3 au, the energetic particle suite on PSP, Integrated Science Investigation of the Sun (IS⊙ IS), observed a series of six SEP events, adding to the limited number of SEP events studied inside of 0.5 au. Variations in the H and He spectra and the He/H abundance ratio are examined and discussed in relation to the identified solar source regions and activity. Methods. IS⊙ IS measures the energetic particle environment from ~20 keV to >100 MeV/nuc. Six events were selected using the ~1 MeV proton intensities, and while small, they were sufficient to calculate proton and helium spectra from ~1 to ~10 MeV/nuc. For the three larger events, the He/H ratio as a function of energy was determined. Using the timing of the associated radio bursts, solar sources were identified for each event and the eruptions were examined in extreme ultraviolet emission. Results. The largest of the selected events has peak ~1 MeV proton intensities of 3.75 (cm2 sr s MeV)-1. Within uncertainties, the He and H spectra have similar power law forms with indices ranging from -2.3 to -3.3. For the three largest events, the He/H ratios are found to be relatively energy independent; however, the ratios differ substantially with values of 0.0033 ± 0.0013, 0.177 ± 0.047, and 0.016 ± 0.009. An additional compositional variation is evident in both the 3He and electron signatures. These variations are particularly interesting as the three larger events are likely a result of similar eruptions from the same active region. © ESO 2021.Immediate accessThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]