210 research outputs found
The Public Health Response to COVID-19 in the Northeast Region of Missouri
The Public Health Response to COVID-19 in the Northeast Region of Missouri documents efforts by Northeast Missouri’s local public health agencies along with other stakeholders to leverage their partnerships, resources, and expertise to respond to COVID-19. Along with professional stakeholder accounts, the report includes residents’ perspectives and experiences during the COVID-19 response. Professional and resident findings helped identify lessons that could strengthen the public health system’s ability to continue responding to COVID-19 and face future crisis with greater resources, coordination, equitable strategies, modernized infrastructure and public trust. The findings in this report center on the period of the pandemic from March 2020 through May 2021, before the proliferation of the Delta and Omicron variants.
The Public Health Response to COVID-19 in the Northeast Region of Missouri along with The Public Health Response to COVID-19 in the Southwest Region of Missouri and The Public Health Response to COVID-19 in the St. Louis Region of Missouri are part of a series of regional reports that were used to inform the state-level recommendations in the report Missouri’s Public Health Response to COVID-19: Key Findings and Recommendations for State Action and Investment
Complex Precipitation Pathways in Multi-Component Alloys
One usual way to strengthen a metal is to add alloying elements and to
control the size and the density of the precipitates obtained. However,
precipitation in multicomponent alloys can take complex pathways depending on
the relative diffusivity of solute atoms and on the relative driving forces
involved. In Al-Zr-Sc alloys, atomic simulations based on first-principle
calculations combined with various complementary experimental approaches
working at different scales reveal a strongly inhomogeneous structure of the
precipitates: owing to the much faster diffusivity of Sc compared with Zr in
the solid solution, and to the absence of Zr and Sc diffusion inside the
precipitates, the precipitate core is mostly Sc-rich, whereas the external
shell is Zr-rich. This explains previous observations of an enhanced nucleation
rate in Al-Zr-Sc alloys compared with binary Al-Sc alloys, along with much
higher resistance to Ostwald ripening, two features of the utmost importance in
the field of light high-strength materials
High-Precision, In Vitro Validation of the Sequestration Mechanism for Generating Ultrasensitive Dose-Response Curves in Regulatory Networks
Our ability to recreate complex biochemical mechanisms in designed, artificial systems provides a stringent test of our understanding of these mechanisms and opens the door to their exploitation in artificial biotechnologies. Motivated by this philosophy, here we have recapitulated in vitro the “target sequestration” mechanism used by nature to improve the sensitivity (the steepness of the input/output curve) of many regulatory cascades. Specifically, we have employed molecular beacons, a commonly employed optical DNA sensor, to recreate the sequestration mechanism and performed an exhaustive, quantitative study of its key determinants (e.g., the relative concentrations and affinities of probe and depletant). We show that, using sequestration, we can narrow the pseudo-linear range of a traditional molecular beacon from 81-fold (i.e., the transition from 10% to 90% target occupancy spans an 81-fold change in target concentration) to just 1.5-fold. This narrowing of the dynamic range improves the sensitivity of molecular beacons to that equivalent of an oligomeric, allosteric receptor with a Hill coefficient greater than 9. Following this we have adapted the sequestration mechanism to steepen the binding-site occupancy curve of a common transcription factor by an order of magnitude over the sensitivity observed in the absence of sequestration. Given the success with which the sequestration mechanism has been employed by nature, we believe that this strategy could dramatically improve the performance of synthetic biological systems and artificial biosensors
Efficient control of atmospheric sulfate production based on three formation regimes
The formation of sulfate (SO₄²⁻) in the atmosphere is linked chemically to its direct precursor, sulfur dioxide (SO₂), through several key oxidation paths for which nitrogen oxides or NO_x (NO and NO₂) play essential roles. Here we present a coherent description of the dependence of SO₄²⁻ formation on SO₂ and NO_x under haze-fog conditions, in which fog events are accompanied by high aerosol loadings and fog-water pH in the range of 4.7–6.9. Three SO₄²⁻ formation regimes emerge as defined by the role played by NO_x. In the low-NO_x regime, NO_x act as catalyst for HO_x, which is a major oxidant for SO₂, whereas in the high-NO_x regime, NO₂ is a sink for HO_x. Moreover, at highly elevated NO_x levels, a so-called NO₂-oxidant regime exists in which aqueous NO₂ serves as the dominant oxidant of SO₂. This regime also exists under clean fog conditions but is less prominent. Sensitivity calculations using an emission-driven box model show that the reduction of SO₄²⁻ is comparably sensitive to the reduction of SO₂ and NO_x emissions in the NO₂-oxidant regime, suggesting a co-reduction strategy. Formation of SO₄²⁻ is relatively insensitive to NO_x reduction in the low-NO_x regime, whereas reduction of NO_x actually leads to increased SO₄²⁻ production in the intermediate high-NO_x regime
Phagocytosis depends on TRPV2-mediated calcium influx and requires TRPV2 in lipids rafts: alteration in macrophages from patients with cystic fibrosis.
Whereas many phagocytosis steps involve ionic fluxes, the underlying ion channels remain poorly defined. As reported in mice, the calcium conducting TRPV2 channel impacts the phagocytic process. Macrophage phagocytosis is critical for defense against pathogens. In cystic fibrosis (CF), macrophages have lost their capacity to act as suppressor cells and thus play a significant role in the initiating stages leading to chronic inflammation/infection. In a previous study, we demonstrated that impaired function of CF macrophages is due to a deficient phagocytosis. The aim of the present study was to investigate TRPV2 role in the phagocytosis capacity of healthy primary human macrophage by studying its activity, its membrane localization and its recruitment in lipid rafts. In primary human macrophages, we showed that P. aeruginosa recruits TRPV2 channels at the cell surface and induced a calcium influx required for bacterial phagocytosis. We presently demonstrate that to be functional and play a role in phagocytosis, TRPV2 might require a preferential localization in lipid rafts. Furthermore, CF macrophage displays a perturbed calcium homeostasis due to a defect in TRPV2. In this context, deregulated TRPV2-signaling in CF macrophages could explain their defective phagocytosis capacity that contribute to the maintenance of chronic infection
Results of a participatory needs assessment demonstrate an opportunity to involve people who use alcohol in drug user activism and harm reduction
BACKGROUND: Drug users’ organizations have made progress in recent years in advocating for the health and human rights of people who use illicit drugs but have historically not emphasized the needs of people who drink alcohol. METHODS: This paper reports on a qualitative participatory needs assessment with people who use illicit substances in British Columbia, Canada. We held workshops in 17 communities; these were facilitated by people who use illicit drugs, recorded with ethnographic fieldnotes, and analyzed using critical theory. RESULTS: Although the workshops were targeted to people who use illicit drugs, people who primarily consume alcohol also attended. An unexpected finding was the potential for drug users’ organizations and other harm reduction programs to involve “illicit drinkers”: people who drink non-beverage alcohol (e.g. mouthwash, rubbing alcohol) and those who drink beverage alcohol in criminalized ways (e.g., homeless drinkers). Potential points of alliance between these groups are common priorities (specifically, improving treatment by health professionals and the police, expanding housing options, and implementing harm reduction services), common values (reducing surveillance and improving accountability of services), and polysubstance use. CONCLUSIONS: Despite these potential points of alliance, there has historically been limited involvement of illicit drinkers in drug users’ activism. Possible barriers to involvement of illicit drinkers in drug users’ organizations include racism (as discourses around alcohol use are highly racialized), horizontal violence, the extreme marginalization of illicit drinkers, and knowledge gaps around harm reduction for alcohol. Understanding the commonalities between people who use drugs and people who use alcohol, as well as the potential barriers to alliance between them, may facilitate the greater involvement of illicit drinkers in drug users’ organizations and harm reduction services
Mutations in DCC cause isolated agenesis of the corpus callosum with incomplete penetrance
Brain malformations involving the corpus callosum are common in children with developmental disabilities. We identified DCC mutations in four families and five sporadic individuals with isolated agenesis of the corpus callosum (ACC) without intellectual disability. DCC mutations result in variable dominant phenotypes with decreased penetrance, including mirror movements and ACC associated with a favorable developmental prognosis. Possible phenotypic modifiers include the type and location of mutation and the sex of the individual
Associations between respiratory illnesses and secondhand smoke exposure in flight attendants: A cross-sectional analysis of the Flight Attendant Medical Research Institute Survey
Abstract Background Secondhand tobacco smoke (SHS) is associated with increased risk of respiratory illness, cancer, and cardiovascular disease. Prior to smoking bans on airlines in the late 1980s, flight attendants were exposed to a significant amount of SHS. In the present study, we examine associations between flight attendant SHS exposure and development of respiratory illnesses and cardiovascular disease. Methods Between December 2006 and October 2010, three hundred sixty-two flight attendants completed an online questionnaire with information regarding experience as a flight attendant, medical history, smoking history, and SHS exposure. Rates of illnesses in flight attendants were compared with an age and smoking history matched population sample from NHANES 2005-2006. Logistic regression analysis was used to examine the association of reported medical conditions and pre-ban years of exposure. Results Compared with the sample from NHANES 2005-2006, flight attendants had increased prevalence of chronic bronchitis (11.7% vs. 7.2%, p < 0.05), emphysema/COPD (3.2% vs. 0.9%, p < 0.03), and sinus problems (31.5% vs. 20.9%, p < 0.002), despite a lower prevalence of medical illnesses including high blood pressure, diabetes, high cholesterol, heart failure, cancer, and thyroid disease. Amongst flight attendants who reported never smoking over their lifetimes, there was not a significant association between years of service as a flight attendant in the pre-smoking ban era and illnesses. However, in this same group, there was a significantly increased risk of daily symptoms (vs. no symptoms) of nasal congestion, throat, or eye irritation per 10-year increase of years of service as a flight attendant prior to the smoking ban (OR 2.14, 95% CI 1.41 - 3.24). Conclusions Flight attendants experience increased rates of respiratory illnesses compared to a population sample. The frequency of symptoms of nasal congestion, throat or eye irritation is associated with occupational SHS exposure in the pre-smoking ban era
Mucociliary and long-term particle clearance in airways of patients with immotile cilia
Spherical monodisperse ferromagnetic iron oxide particles of 1.9 μm geometric and 4.2 μm aerodynamic diameter were inhaled by seven patients with primary ciliary dyskinesia (PCD) using the shallow bolus technique, and compared to 13 healthy non-smokers (NS) from a previous study. The bolus penetration front depth was limiting to the phase1 dead space volume. In PCD patients deposition was 58+/-8 % after 8 s breath holding time. Particle retention was measured by the magnetopneumographic method over a period of nine months. Particle clearance from the airways showed a fast and a slow phase. In PCD patients airway clearance was retarded and prolonged, 42+/-12 % followed the fast phase with a mean half time of 16.8+/-8.6 hours. The remaining fraction was cleared slowly with a half time of 121+/-25 days. In healthy NS 49+/-9 % of particles were cleared in the fast phase with a mean half time of 3.0+/-1.6 hours, characteristic of an intact mucociliary clearance. There was no difference in the slow clearance phase between PCD patients and healthy NS. Despite non-functioning cilia the effectiveness of airway clearance in PCD patients is comparable to healthy NS, with a prolonged kinetics of one week, which may primarily reflect the effectiveness of cough clearance. This prolonged airway clearance allows longer residence times of bacteria and viruses in the airways and may be one reason for increased frequency of infections in PCD patients
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