173 research outputs found
Stellar Signatures of AGN Jet Triggered Star Formation
To investigate feedback between relativistic jets emanating from Active
Galactic Nuclei (AGN) and the stellar population of the host galaxy, we analyze
the long-term evolution of the galaxy-scale simulations by Gaibler et al.
(2012) of jets in massive, gas-rich galaxies at z ~ 2 - 3 and of stars formed
in the host galaxies. We find strong, jet-induced differences in the resulting
stellar populations of galaxies that host relativistic jets and galaxies that
do not, including correlations in stellar locations, velocities, and ages. Jets
are found to generate distributions of increased radial and vertical velocities
that persist long enough to effectively extend the stellar structure of the
host. The jets cause the formation of bow shocks that move out through the
disk, generating rings of star formation within the disk. The bow shock often
accelerates pockets of gas in which stars form, yielding populations of stars
with significant radial and vertical velocities, some of which have large
enough velocities to escape the galaxy. These stellar population signatures can
serve to identify past jet activity as well as jet-induced star formation
Religion in American Public Life (with transcript)
Sarah Gordon and Mark Silk look at how the U.S. has historically regulated religious institutions as well as accounted for an individual’s religious liberty
Religion in American Public Life (with transcript)
Sarah Gordon and Mark Silk look at how the U.S. has historically regulated religious institutions as well as accounted for an individual’s religious liberty
Med Moth: A Storytelling Platform for Improving Wellness in Medical Education
Background: Burnout is a major issue amongst medical students and professionals that demands a solution. Mindfulness has been shown to decrease burnout. Storytelling, as a form of mindfulness, leads to reflection. Few publications have studied the effect of storytelling on student and clinician wellness. To address wellness within their medical community and utilize the underexplored method of narrative medicine as a curricular enhancement, the authors designed and implemented a novel storytelling platform, Med Moth, at the University of Massachusetts Medical School (UMMS) and associated hospital (UMass Memorial Medical Center).
Methods: Members of the community were invited to storytelling events to listen to and share stories about formative medical experiences. Four events were held between 2017 and 2018. After each event, participants received a survey inquiring how attendance benefitted them personally and professionally.
Results: Clinicians, students, and faculty comprised the 104 first-time attendees surveyed. Med Moth produced a strong perceived benefit to surrogate measures including emotional exhaustion and depersonalization, defining characteristics of burnout, and professional development. Among these three measures, 66% of participants rated 4-5 (out of 5). Nearly all attendees (96%) rated 4-5 for the overall experience. Lastly, medical students reported a higher benefit regarding professional development than clinicians (p=0.002).
Conclusions: This pilot study of a novel storytelling platform demonstrates positive personal and professional development outcomes, both during and after medical school training. Medical schools, residency programs, and medical institutions should strongly consider the implementation of such a wellness platform to build resiliency and to mitigate burnout through reflection
A Dominant Role for the Immunoproteasome in CD8+ T Cell Responses to Murine Cytomegalovirus
Murine cytomegalovirus (MCMV) is an important animal model of human cytomegalovirus (HCMV), a β-Herpesvirus that infects the majority of the world's population and causes disease in neonates and immunocompromised adults. CD8+ T cells are a major part of the immune response to MCMV and HCMV. Processing of peptides for presentation to CD8+ T cells may be critically dependent on the immunoproteasome, expression of which is affected by MCMV. However, the overall importance of the immunoproteasome in the generation of immunodominant peptides from MCMV is not known. We therefore examined the role of the immunoproteasome in stimulation of CD8+ T cell responses to MCMV – both conventional memory responses and those undergoing long-term expansion or “inflation”. We infected LMP7−/− and C57BL/6 mice with MCMV or with newly-generated recombinant vaccinia viruses (rVVs) encoding the immunodominant MCMV protein M45 in either full-length or epitope-only minigene form. We analysed CD8+ T cell responses using intracellular cytokine stain (ICS) and MHC Class I tetramer staining for a panel of MCMV-derived epitopes. We showed a critical role for immunoproteasome in MCMV affecting all epitopes studied. Interestingly we found that memory “inflating” epitopes demonstrate reduced immunoproteasome dependence compared to non-inflating epitopes. M45-specific responses induced by rVVs remain immunoproteasome-dependent. These results help to define a critical restriction point for CD8+ T cell epitopes in natural cytomegalovirus (CMV) infection and potentially in vaccine strategies against this and other viruses
Chimpanzees (Pan troglodytes) do not Develop Contingent Reciprocity in an Experimental Task
Chimpanzees provide help to unrelated individuals in a broad range of situations. The pattern of helping within pairs suggests that contingent reciprocity may have been an important mechanism in the evolution of altruism in chimpanzees. However, correlational analyses of the cumulative pattern of interactions over time do not demonstrate that helping is contingent upon previous acts of altruism, as required by the theory of reciprocal altruism. Experimental studies provide a controlled approach to examine the importance of contingency in helping interactions. In this study, we evaluated whether chimpanzees would be more likely to provide food to a social partner from their home group if their partner had previously provided food for them. The chimpanzees manipulated a barpull apparatus in which actors could deliver rewards either to themselves and their partners or only to themselves. Our findings indicate that the chimpanzees’ responses were not consistently influenced by the behavior of their partners in previous rounds. Only one of the 11 dyads that we tested demonstrated positive reciprocity. We conclude that contingent reciprocity does not spontaneously arise in experimental settings, despite the fact patterns of behavior in the field indicate that individuals cooperate preferentially with reciprocating partners
Chimpanzees Do Not Take Advantage of Very Low Cost Opportunities to Deliver Food to Unrelated Group Members
We conducted experiments on two populations of chimpanzees, Pan troglodytes, to determine whether they would take advantage of opportunities to provide food rewards to familiar group members at little cost to themselves. In both of the experiments described here, chimpanzees were able to deliver identical rewards to themselves and to other members of their social groups. We compared the chimpanzees\u27 behaviour when they were paired with another chimpanzee and when they were alone. If chimpanzees are motivated to provide benefits to others, they are expected to consistently deliver rewards to others and to distinguish between the partner-present and partner-absent conditions. Results from both experiments indicate that our subjects were largely indifferent to the benefits they could provide to others. They were less likely to provide rewards to potential recipients as the experiment progressed, and all but one of the 18 subjects were as likely to deliver rewards to an empty enclosure as to an enclosure housing another chimpanzee. These results, in conjunction with similar results obtained in previous experiments, suggest that chimpanzees are not motivated by prosocial sentiments to provide food rewards to other group members. The Association for the Study of Animal Behaviour. Published by Elsevier Ltd
Utilizing the adjuvant properties of CD1d-dependent NK T cells in T cell–mediated immunotherapy
Understanding the role of serological and clinical data on assessing the dynamic of malaria transmission: a case study of Bagamoyo district, Tanzania
A research article is submitted in Research | Volume 43, Article 60, 07 Oct 2022Introduction: naturally acquired blood-stage malaria antibodies and malaria clinical data have been reported to be useful in monitoring malaria change over time and as a marker of malaria exposure. This study assessed the totalimmunoglobulin G (IgG) levels to Plasmodium falciparum schizont among infants (5-17 months), estimated malaria incidence using routine health
Facility-based surveillance data and predicted trend relation between anti-schizont antibodies and malaria incidence in Bagamoyo. Methods: 252 serum samples were used for assessment of total IgG by enzyme-linked immunosorbent assay and results were expressed in arbitrary units (AU).147/252 samples were collected in 2021 during a blood-stage malaria vaccine trial [ClinicalTrials.gov NCT04318002], and 105/252 were archived samples of malaria vaccine trial conducted in 2012 [ClinicalTrials.gov NCT00866619]. Malaria incidence was calculated from outpatient clinic data of malaria rapid test or blood smear positive results retrieved from District-Health-Information- Software-2 (DHIS2) between 2013 and 2020. Cross-sectional data from both studies were analyzed using STATA version 14. Results: this study demonstrated a decline in total anti-schizont IgG
levels from 490.21AU in 2012 to 97.07AU in 2021 which was related to a fall in incidence from 58.25 cases/1000 person-year in 2013 to 14.28 cases/1000 person-year in 2020. We also observed a significant difference in incidence when comparing high and low malaria transmission areas and by gender. However, we did not observe differences when comparing total anti-schizont
antibodies by gender and study year.
Conclusion: total anti-schizont antibody levels appear to be an important serological marker of exposure for assessing the dynamic of malaria transmission in infants living in malaria-endemic regions
Poor CD4+ T Cell Immunogenicity Limits Humoral Immunity to P. falciparum Transmission-Blocking Candidate Pfs25 in Humans.
Plasmodium falciparum transmission-blocking vaccines (TBVs) targeting the Pfs25 antigen have shown promise in mice but the same efficacy has never been achieved in humans. We have previously published pre-clinical data related to a TBV candidate Pfs25-IMX313 encoded in viral vectors which was very promising and hence progressed to human clinical trials. The results from the clinical trial of this vaccine were very modest. Here we unravel why, contrary to mice, this vaccine has failed to induce robust antibody (Ab) titres in humans to elicit transmission-blocking activity. We examined Pfs25-specific B cell and T follicular helper (Tfh) cell responses in mice and humans after vaccination with Pfs25-IMX313 encoded by replication-deficient chimpanzee adenovirus serotype 63 (ChAd63) and the attenuated orthopoxvirus modified vaccinia virus Ankara (MVA) delivered in the heterologous prime-boost regimen via intramuscular route. We found that after vaccination, the Pfs25-IMX313 was immunologically suboptimal in humans compared to mice in terms of serum Ab production and antigen-specific B, CD4+ and Tfh cell responses. We identified that the key determinant for the poor anti-Pfs25 Ab formation in humans was the lack of CD4+ T cell recognition of Pfs25-IMX313 derived peptide epitopes. This is supported by correlations established between the ratio of proliferated antigen-specific CD4+/Tfh-like T cells, CXCL13 sera levels, and the corresponding numbers of circulating Pfs25-specific memory B cells, that consequently reflected on antigen-specific IgG sera levels. These correlations can inform the design of next-generation Pfs25-based vaccines for robust and durable blocking of malaria transmission
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