On the dust of tailless Oort-cloud comet C/2020 T2 (Palomar)

We report our new analysis of Oort-cloud comet C/2020 T2 (Palomar) (T2) observed at 2.06 au from the Sun (phase angle of 28.5 deg) about two weeks before perihelion. T2 lacks a significant dust tail in scattered light, showing a strong central condensation of the coma throughout the apparition, reminiscent of so-called Manx comets. Its spectral slope of polarized light increases and decreases in the J (1.25 um) and H (1.65 um) bands, respectively, resulting in an overall negative (blue) slope (-0.31+/-0.14 % um^-1) in contrast to the red polarimetric color of active comets observed at similar geometries. The average polarization degree of T2 is 2.86+/-0.17 % for the J and 2.75+/-0.16 % for the H bands. Given that near-infrared wavelengths are sensitive to the intermediate-scale structure of cometary dust (i.e., dust aggregates), our light-scattering modeling of ballistic aggregates with different porosities and compositions shows that polarimetric properties of T2 are compatible with low-porosity (~66 %), absorbing dust aggregates with negligible ice contents on a scale of 10--100 um (density of ~652 kg m^-3). This is supported by the coma morphology of T2 which has a viable beta (the relative importance of solar radiation pressure on dust) range of <~10^-4. Secular evolution of the r-band activity of T2 from archival data reveals that the increase in its brightness accelerates around 2.4 au pre-perihelion, with its overall dust production rate ~100 times smaller than those of active Oort-cloud comets. We also found an apparent concentration of T2 and Manx comets toward ecliptic orbits. This paper underlines the heterogeneous nature of Oort-cloud comets which can be investigated in the near future with dedicated studies of their dust characteristics.Comment: Accepted for publication in Astronomy & Astrophysic

Deregulation of HDAC5 by Viral Interferon Regulatory Factor 3 Plays an Essential Role in Kaposi's Sarcoma-Associated Herpesvirus-Induced Lymphangiogenesis.

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent for Kaposi's sarcoma (KS), which is one of the most common HIV-associated neoplasms. The endothelium is the thin layer of squamous cells where vascular blood endothelial cells (BECs) line the interior surface of blood vessels and lymphatic endothelial cells (LECs) are in direct contact with lymphatic vessels. The KS lesions contain a prominent compartment of neoplastic spindle morphology cells that are closely related to LECs. Furthermore, while KSHV can infect both LECs and BECs in vitro, its infection activates genetic programming related to lymphatic endothelial cell fate, suggesting that lymphangiogenic pathways are involved in KSHV infection and malignancy. Here, we report for the first time that viral interferon regulatory factor 3 (vIRF3) is readily detected in over 40% of KS lesions and that vIRF3 functions as a proangiogenic factor, inducing hypersprouting formation and abnormal growth in a LEC-specific manner. Mass spectrometry analysis revealed that vIRF3 interacted with histone deacetylase 5 (HDAC5), which is a signal-responsive regulator for vascular homeostasis. This interaction blocked the phosphorylation-dependent cytosolic translocation of HDAC5 and ultimately altered global gene expression in LECs but not in BECs. Consequently, vIRF3 robustly induced spindle morphology and hypersprouting formation of LECs but not BECs. Finally, KSHV infection led to the hypersprouting formation of LECs, whereas infection with a ΔvIRF3 mutant did not do so. Collectively, our data indicate that vIRF3 alters global gene expression and induces a hypersprouting formation in an HDAC5-binding-dependent and LEC-specific manner, ultimately contributing to KSHV-associated pathogenesis.IMPORTANCE Several lines of evidences indicate that KSHV infection of LECs induces pathological lymphangiogenesis and that the results resemble KS-like spindle morphology. However, the underlying molecular mechanism remains unclear. Here, we demonstrated that KSHV vIRF3 is readily detected in over 40% of various KS lesions and functions as a potent prolymphangiogenic factor by blocking the phosphorylation-dependent cytosolic translocation of HDAC5, which in turn modulates global gene expression in LECs. Consequently, vIRF3-HDAC5 interaction contributes to virus-induced lymphangiogenesis. The results of this study suggest that KSHV vIRF3 plays a crucial role in KSHV-induced malignancy

Social Facilitation in Fear Appeals Creates Positive Affect but Inhibits Healthy Eating Intentions

The social facilitation of eating plays a significant role in influencing individuals’ eating decisions. However, how social eating cues are processed in health promotion messages is unclear. This study examined individuals’ food craving in response to social cues in images (Experiment 1) and emotional experiences, perceived threat, perceived efficacy, behavioral intentions, and motivational coactivation elicited by social eating cues in obesity prevention fear appeals (Experiment 2). Results suggested that the presence of a group of people eating in an image facilitated food craving for the presented foods. Moreover, fear appeals that presented obesity and its consequences with more social eating cues, versus individual eating cues, generated greater positive emotional responses, perceived threat severity, response and self-efficacy, and motivational coactivation indicating more attention and threat vigilance. However, these cues also generated fewer self-reported intentions to change unhealthy eating behaviors. Implications and suggestions for future research are discussed

Monitoring Observations of the Jupiter-Family Comet 17P/Holmes during 2014 Perihelion Passage

We performed a monitoring observation of a Jupiter-Family comet, 17P/Holmes, during its 2014 perihelion passage to investigate its secular change in activity. The comet has drawn the attention of astronomers since its historic outburst in 2007, and this occasion was its first perihelion passage since then. We analyzed the obtained data using aperture photometry package and derived the Afrho parameter, a proxy for the dust production rate. We found that Afrho showed asymmetric properties with respect to the perihelion passage: it increased moderately from 100 cm at the heliocentric distance r_h=2.6-3.1 AU to a maximal value of 185 cm at r_h = 2.2 AU (near the perihelion) during the inbound orbit, while dropping rapidly to 35 cm at r_h = 3.2 AU during the outbound orbit. We applied a model for characterizing dust production rates as a function of r_h and found that the fractional active area of the cometary nucleus had dropped from 20%-40% in 2008-2011 (around the aphelion) to 0.1%-0.3% in 2014-2015 (around the perihelion). This result suggests that a dust mantle would have developed rapidly in only one orbital revolution around the sun. Although a minor eruption was observed on UT 2015 January 26 at r_h = 3.0 AU, the areas excavated by the 2007 outburst would be covered with a layer of dust (<~ 10 cm depth) which would be enough to insulate the subsurface ice and to keep the nucleus in a state of low activity.Comment: 25 pages, 6 figures, 2 tables, ApJ accepted on December 29, 201

Regional and racial variations in the utilization of endoscopic retrograde cholangiopancreatography among pancreatic cancer patients in the United States

BackgroundPancreatic cancer is projected to become the second leading cause of cancerâ related deaths by 2030. Endoscopic retrograde cholangiopancreatography (ERCP) is recommended as firstâ line therapy for biliary decompression in pancreatic cancer. The aim of our study was to characterize geographic and racial/ethnic disparities in ERCP utilization among patients with pancreatic cancer.MethodsRetrospective cohort study using the US Surveillance, Epidemiology, and End Results (SEER)â Medicare database to identify patients diagnosed with pancreatic cancer from 2003â 2013. The primary outcome was receipt of ERCP, with or without stent placement, vs any nonâ ERCP biliary intervention.ResultsOf the 36 619 patients with pancreatic cancer, 37.5% (n = 13 719) underwent an ERCP, percutaneous drainage, or surgical biliary bypass. The most common biliary intervention (82.6%) was ERCP. After adjusting for tumor location and stage, Blacks were significantly less likely to receive ERCP than Whites (aOR 0.84, 95% CI 0.72, 0.97) and more likely to receive percutaneous transhepatic biliary drainage (PTBD) (aOR 1.38, 95% CI 1.14, 1.66). Patients in the Southeast and the West were more likely to receive ERCP than those in the Northeast (Southeast aOR 1.21, 95% CI 1.04, 1.40; West aOR 1.16, 95% CI 1.01, 1.32).ConclusionRacial/ethnic and geographic disparities in access to biliary interventions including ERCP exist for patients with pancreatic cancer in the United States. Our results highlight the need for further research and policies to improve access to appropriate biliary intervention for all patients.To date, disparities in the receipt of endoscopic therapies among patients with pancreatic cancer have not been reported. The results from our study suggest that blacks with pancreatic cancer and patients in the Northeast region of the US are less likely to receive the gold standard therapy for obstructive jaundice.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149758/1/cam42225_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149758/2/cam42225.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149758/3/cam42225-sup-0001-Supinfo.pd

Dopamine D3 Receptors Inhibit Hippocampal Gamma Oscillations by Disturbing CA3 Pyramidal Cell Firing Synchrony

Cortical gamma oscillations are associated with cognitive processes and are altered in several neuropsychiatric conditions such as schizophrenia and Alzheimer’s disease. Since dopamine D3 receptors are possible targets in treatment of these conditions, it is of great importance to understand their role in modulation of gamma oscillations. The effect of D3 receptors on gamma oscillations and the underlying cellular mechanisms were investigated by extracellular local field potential and simultaneous intracellular sharp micro-electrode recordings in the CA3 region of the hippocampus in vitro. D3 receptors decreased the power and broadened the bandwidth of gamma oscillations induced by acetylcholine or kainate. Blockade of the D3 receptors resulted in faster synchronization of the oscillations, suggesting that endogenous dopamine in the hippocampus slows down the dynamics of gamma oscillations by activation of D3 receptors. Investigating the underlying cellular mechanisms for these effects showed that D3 receptor activation decreased the rate of action potentials (APs) during gamma oscillations and reduced the precision of the AP phase coupling to the gamma cycle in CA3 pyramidal cells. The results may offer an explanation how selective activation of D3 receptors may impair cognition and how, in converse, D3 antagonists may exert pro-cognitive and antipsychotic effects

Neuroinflammation, Mast Cells, and Glia: Dangerous Liaisons

The perspective of neuroinflammation as an epiphenomenon following neuron damage is being replaced by the awareness of glia and their importance in neural functions and disorders. Systemic inflammation generates signals that communicate with the brain and leads to changes in metabolism and behavior, with microglia assuming a pro-inflammatory phenotype. Identification of potential peripheral-to-central cellular links is thus a critical step in designing effective therapeutics. Mast cells may fulfill such a role. These resident immune cells are found close to and within peripheral nerves and in brain parenchyma/meninges, where they exercise a key role in orchestrating the inflammatory process from initiation through chronic activation. Mast cells and glia engage in crosstalk that contributes to accelerate disease progression; such interactions become exaggerated with aging and increased cell sensitivity to stress. Emerging evidence for oligodendrocytes, independent of myelin and support of axonal integrity, points to their having strong immune functions, innate immune receptor expression, and production/response to chemokines and cytokines that modulate immune responses in the central nervous system while engaging in crosstalk with microglia and astrocytes. In this review, we summarize the findings related to our understanding of the biology and cellular signaling mechanisms of neuroinflammation, with emphasis on mast cell-glia interactions

Emergence of the brain-border immune niches and their contribution to the development of neurodegenerative diseases

Historically, the central nervous system (CNS) was regarded as ‘immune-privileged’, possessing its own distinct immune cell population. This immune privilege was thought to be established by a tight blood-brain barrier (BBB) and blood-cerebrospinal-fluid barrier (BCSFB), which prevented the crossing of peripheral immune cells and their secreted factors into the CNS parenchyma. However, recent studies have revealed the presence of peripheral immune cells in proximity to various brain-border niches such as the choroid plexus, cranial bone marrow (CBM), meninges, and perivascular spaces. Furthermore, emerging evidence suggests that peripheral immune cells may be able to infiltrate the brain through these sites and play significant roles in driving neuronal cell death and pathology progression in neurodegenerative disease. Thus, in this review, we explore how the brain-border immune niches may contribute to the pathogenesis of neurodegenerative disorders such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and multiple sclerosis (MS). We then discuss several emerging options for harnessing the neuroimmune potential of these niches to improve the prognosis and treatment of these debilitative disorders using novel insights from recent studies

Persistence of African Swine Fever Virus in Feed and Feed Mill Environment over Time after Manufacture of Experimentally Inoculated Feed

To reduce the risk of disease from harmful feed-based pathogens, some feed manufacturers quarantine high-risk ingredients prior to their inclusion in feed. Data exist that confirms this practice is effective, but to our knowledge there is no information about porcine pathogen survival in mill environments. The objective of this study was to determine survival of African swine fever virus (ASFV) in swine feed and on mill surfaces after manufacture of experimentally inoculated swine feed. A pilot-scale feed mill was placed within a biosecurity level (BSL) 3 facility to manufacture batches of feed. The priming batch, Batch 1, was ASFV-free feed and was followed with Batch 2 which was experimentally inoculated with ASFV (5.6 × 104 TCID50/gram). Four subsequent ASFV-free batches were then manufactured (Batch 3-6). After each batch of feed, 10 feed samples were aseptically collected in a double ‘X’ pattern. During feed manufacturing, 24 steel coupons were placed on the floor of the manufacturing area and feed dust was allowed to settle onto them overnight. Once feed manufacturing was completed, feed samples and steel coupons were stored at room temperature. On the day of (day 0) and d 3, 7, 14, 28, 60, 90, and 180 after feed manufacturing, feed samples and 3 steel coupons were randomly selected, taken out of storage, and analyzed for ASFV DNA. For feed samples there was a statistically significant (P = 0.023) batch × day interaction for log10 genomic copies per gram of feed, and a marginal statistical significance (P = 0.072) for batch × day interaction for cycle threshold (Ct) values. This indicates that the batch of feed and days held at room temperature impacted the amount of the detectable ASFV DNA in feed samples. There was no evidence (P = 0.433) of ASFV degradation on environmental coupons over the 180-d storage period. This study found that quarantine time can help reduce, but not eliminate ASFV DNA in feed over time. Surprisingly, ASFV DNA is detectable on feed manufacturing surfaces for at least 180 days