Modeling Algae Self-Replenishment

This paper presents a sunlight-dependent algae growth model. Driven by the circumstances surrounding Lake Chapala, Mexico, this theoretical model is an endeavor to understand the resilient sustainability of algae that threatens the area’s ecosystem. In this paper, free-floating algae (phytoplankton) are treated as two distinct populations according to their location in the body of water: the vibrant sunlit upper region and the stagnate lower region where photosynthesis is not possible. The numerical solution for the model is analyzed and results are discussed in light of previous studies and the state of Lake Chapala

The chemerin knockout rat reveals chemerin dependence in female, but not male, experimental hypertension

Measures of the adipokine chemerin are elevated in multiple cardiovascular diseases, including hypertension, but little mechanistic work has been done to implicate chemerin as being causative in such diseases. The chemerin knockout (KO) rat was created to test the hypothesis that removal of chemerin would reduce pressure in the normal and hypertensive state. Western analyses confirmed loss of chemerin in the plasma and tissues of the KO vs. wild‐type (WT) rats. Chemerin concentration in plasma and tissues was lower in WT females than in WT males, as determined by Western analysis. Conscious male and female KO rats had modest differences in baseline measures vs. the WT that included systolic, diastolic, mean arterial and pulse pressures, and heart rate, all measured telemetrically. The mineralocorticoid deoxycorticosterone acetate (DOCA) and salt water, combined with uninephrectomy as a hypertensive stimulus, elevated mean and systolic blood pressures of the male KO higher than the male WT. By contrast, all pressures in the female KO were lower than their WT throughout DOCA‐salt treatment. These results revealed an unexpected sex difference in chemerin expression and the ability of chemerin to modify blood pressure in response to a hypertensive challenge.—Watts, S. W., Darios, E. S., Mullick, A. E., Garver, H., Saunders, T. L., Hughes, E. D., Filipiak, W. E., Zeidler, M. G., McMullen, N., Sinal, C. J., Kumar, R. K., Ferland, D. J., Fink, G. D. The chemerin knockout rat reveals chemerin dependence in female, but not male, experimental hypertension. FASEB J. 32, 6596–6614 (2018). www.fasebj.orgPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154357/1/fsb2fj201800479.pd

The NANOGrav 11-Year Data Set: Limits on Gravitational Waves from Individual Supermassive Black Hole Binaries

Observations indicate that nearly all galaxies contain supermassive black holes (SMBHs) at their centers. When galaxies merge, their component black holes form SMBH binaries (SMBHBs), which emit low-frequency gravitational waves (GWs) that can be detected by pulsar timing arrays (PTAs). We have searched the recently-released North American Nanohertz Observatory for Gravitational Waves (NANOGrav) 11-year data set for GWs from individual SMBHBs in circular orbits. As we did not find strong evidence for GWs in our data, we placed 95\% upper limits on the strength of GWs from such sources as a function of GW frequency and sky location. We placed a sky-averaged upper limit on the GW strain of $h_0 < 7.3(3) \times 10^{-15}$ at $f_\mathrm{gw}= 8$ nHz. We also developed a technique to determine the significance of a particular signal in each pulsar using ``dropout' parameters as a way of identifying spurious signals in measurements from individual pulsars. We used our upper limits on the GW strain to place lower limits on the distances to individual SMBHBs. At the most-sensitive sky location, we ruled out SMBHBs emitting GWs with $f_\mathrm{gw}= 8$ nHz within 120 Mpc for $\mathcal{M} = 10^9 \, M_\odot$, and within 5.5 Gpc for $\mathcal{M} = 10^{10} \, M_\odot$. We also determined that there are no SMBHBs with $\mathcal{M} > 1.6 \times 10^9 \, M_\odot$ emitting GWs in the Virgo Cluster. Finally, we estimated the number of potentially detectable sources given our current strain upper limits based on galaxies in Two Micron All-Sky Survey (2MASS) and merger rates from the Illustris cosmological simulation project. Only 34 out of 75,000 realizations of the local Universe contained a detectable source, from which we concluded it was unsurprising that we did not detect any individual sources given our current sensitivity to GWs.Comment: 10 pages, 11 figures. Accepted by Astrophysical Journal. Please send any comments/questions to S. J. Vigeland ([email protected]

Photoionization of alkali and alkaline earth atoms: Na and Mg

Determinations of the photoionization cross sections of ground state magnesium atoms and excited state sodium atoms have been made over a wide wavelength range. The ground state measurement in magnesium was performed using synchrotron radiation from the uv ring at the National Synchrotron Light Source. Several autoionizing resonances were observed. The photoionization cross section of excited sodium atoms was determined by irradiating laser-produced Na(3p) with synchrotron light. In both cases, agreement with theory is excellent

Chiang Kai-shek’s “secret deal” at Xian and the start of the Sino-Japanese War

Using newly available archives, particularly the diary and the presidential papers of Chiang Kai-shek, this article challenges the conventional interpretations of the Xian Incident (1936), in particular the widely held belief that the kidnapping of China’s leader Chiang by two rebellious generals forced him to form a united front with the Communist Party to confront Japanese aggression, and of the outbreak of the Sino-Japanese War 7 months later. It puts forth the interpretation that full-scale war between China and Japan was started not by Japan but by Chiang after a Japanese provocation, and the united front was only formed after Chiang ordered his best army units to attack Japanese forces in Shanghai in August 1937 turning it into the largest land battle after the First World War. It must be noted, however, that Japan acted provocatively and aggressively in a local incident outside Beijing a month earlier. Chiang decided on war not because he reached an agreement with the Chinese Communists to form a united front whilst a captive in Xian but because in Xian he received a signal from Josef Stalin that the Soviet Union would support him in a war with Japan. Chiang read Stalin right and the Soviet Union became the largest supplier of weapons to China in the first 4 years of China’s 8-year war with Japan. The hitherto unknown or “secret deal” Chiang made in Xian was an implicit one with Stalin, not with the Chinese Communist Party or its man on the spot Zhou Enlai

Do RCAN1 proteins link chronic stress with neurodegeneration?

It has long been suspected that chronic stress can exacerbate, or even cause, disease. We now propose that the RCAN1 gene, which can generate several RCAN1 protein isoforms, may be at least partially responsible for this phenomenon. We review data showing that RCAN1 proteins can be induced by multiple stresses, and present new data also implicating psychosocial/emotional stress in RCAN1 induction. We further show that transgenic mice overexpressing the RCAN1-1L protein exhibit accumulation of hyperphosphorylated tau protein (AT8 antibody), an early precursor to the formation of neurofibrillary tangles and neurodegeneration of the kind seen in Alzheimer disease. We propose that, although transient induction of the RCAN1 gene might protect cells against acute stress, persistent stress may cause chronic RCAN1 overexpression, resulting in serious side effects. Chronically elevated levels of RCAN1 proteins may promote or exacerbate various diseases, including tauopathies such as Alzheimer disease. We propose that the mechanism by which stress can lead to these diseases involves the inhibition of calcineurin and the induction of GSK-3 beta by RCAN1 proteins. Both inhibition of calcineurin and induction of GSK-3 beta contribute to accumulation of phosphorylated tau, formation of neurofibrillary tangles, and eventual neurodegeneration.-Ermak, G., Pritchard, M. A., Dronjak, S., Niu, B., Davies, K. J. A. Do RCAN1 proteins link chronic stress with neurodegeneration? FASEB J. 25, 3306-3311 (2011). www.fasebj.or

Accounting Problems Under the Excess Profits Tax

DNA vaccines based on subunits from pathogens have several advantages over other vaccine strategies. DNA vaccines can easily be modified, they show good safety profiles, are stable and inexpensive to produce, and the immune response can be focused to the antigen of interest. However, the immunogenicity of DNA vaccines which is generally quite low needs to be improved. Electroporation and co-delivery of genetically encoded immune adjuvants are two strategies aiming at increasing the efficacy of DNA vaccines. Here, we have examined whether targeting to antigen-presenting cells (APC) could increase the immune response to surface envelope glycoprotein (Env) gp120 from Human Immunodeficiency Virus type 1 (HIV- 1). To target APC, we utilized a homodimeric vaccine format denoted vaccibody, which enables covalent fusion of gp120 to molecules that can target APC. Two molecules were tested for their efficiency as targeting units: the antibody-derived single chain Fragment variable (scFv) specific for the major histocompatilibility complex (MHC) class II I-E molecules, and the CC chemokine ligand 3 (CCL3). The vaccines were delivered as DNA into muscle of mice with or without electroporation. Targeting of gp120 to MHC class II molecules induced antibodies that neutralized HIV-1 and that persisted for more than a year after one single immunization with electroporation. Targeting by CCL3 significantly increased the number of HIV-1 gp120-reactive CD8(+) T cells compared to non-targeted vaccines and gp120 delivered alone in the absence of electroporation. The data suggest that chemokines are promising molecular adjuvants because small amounts can attract immune cells and promote immune responses without advanced equipment such as electroporation.Funding Agencies|Research Council of Norway; Odd Fellow</p

Multi-Messenger Gravitational Wave Searches with Pulsar Timing Arrays: Application to 3C66B Using the NANOGrav 11-year Data Set

When galaxies merge, the supermassive black holes in their centers may form binaries and, during the process of merger, emit low-frequency gravitational radiation in the process. In this paper we consider the galaxy 3C66B, which was used as the target of the first multi-messenger search for gravitational waves. Due to the observed periodicities present in the photometric and astrometric data of the source of the source, it has been theorized to contain a supermassive black hole binary. Its apparent 1.05-year orbital period would place the gravitational wave emission directly in the pulsar timing band. Since the first pulsar timing array study of 3C66B, revised models of the source have been published, and timing array sensitivities and techniques have improved dramatically. With these advances, we further constrain the chirp mass of the potential supermassive black hole binary in 3C66B to less than $(1.65\pm0.02) \times 10^9~{M_\odot}$ using data from the NANOGrav 11-year data set. This upper limit provides a factor of 1.6 improvement over previous limits, and a factor of 4.3 over the first search done. Nevertheless, the most recent orbital model for the source is still consistent with our limit from pulsar timing array data. In addition, we are able to quantify the improvement made by the inclusion of source properties gleaned from electromagnetic data to `blind' pulsar timing array searches. With these methods, it is apparent that it is not necessary to obtain exact a priori knowledge of the period of a binary to gain meaningful astrophysical inferences.Comment: 14 pages, 6 figures. Accepted by Ap

Hard and Blind: On Wittgenstein's Genealogical View of Logical Necessity

My main aim is to sketch a certain reading (‘genealogical') of later Wittgenstein's views on logical necessity. Along the way, I engage with the inferentialism currently debated in the literature on the epistemology of deductive logic.publishedVersio

THE NANOGRAV NINE-YEAR DATA SET: LIMITS ON THE ISOTROPIC STOCHASTIC GRAVITATIONAL WAVE BACKGROUND

We compute upper limits on the nanohertz-frequency isotropic stochastic gravitational wave background (GWB) using the 9 year data set from the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) collaboration. Well-tested Bayesian techniques are used to set upper limits on the dimensionless strain amplitude (at a frequency of 1 yr-1) for a GWB from supermassive black hole binaries of Agw \u3c 1.5 × 10-15. We also parameterize the GWB spectrum with a broken power-law model by placing priors on the strain amplitude derived from simulations of Sesana and McWilliams et al. Using Bayesian model selection we find that the data favor a broken power law to a pure power law with odds ratios of 2.2 and 22 to one for the Sesana and McWilliams prior models, respectively. Using the broken power-law analysis we construct posterior distributions on environmental factors that drive the binary to the GW-driven regime including the stellar mass density for stellar-scattering, mass accretion rate for circumbinary disk interaction, and orbital eccentricity for eccentric binaries, marking the first time that the shape of the GWB spectrum has been used to make astrophysical inferences. Returning to a power-law model, we place stringent limits on the energy density of relic GWs, Ωgw(f)h2 \u3c 4.2 × 10-10. Our limit on the cosmic string GWB, Ωgw(f)h2 \u3c 2.2 × 10-10, translates to a conservative limit on the cosmic string tension with Gμ \u3c 3.3 × 10-8, a factor of four better than the joint Planck and high-l cosmic microwave background data from other experiments