335 research outputs found
External Electron Injection for the AWAKE Experiment
We summarize and explain the realization of witness particle injection into
wakefields for the AWAKE experiment. In AWAKE, the plasma wakefields are driven
by a self-modulating relativistic proton bunch. To demonstrate that these
wakefields can accelerate charged particles, we inject a \unit[10-20]{MeV}
electron bunch produced by a photo-injector. We summarize the experimental
challenges of this injection process and present our plans for the near future.Comment: 4 pages, 3 figure
Nelson's Ridge Subdivision: conservation approach to rural subdivision development
Master of Landscape ArchitectureDepartment of Landscape Architecture/Regional and Community PlanningMary C. Kingery-PageA 2009 research report by the U.S. Census Bureau and the National Resources Inventory predicts that the developed area in the United States will increase by 54.4 million acres during the next 25 years (McMahon 2010, 2). America’s rural landscape and character is replaced everyday by “placeless” neighborhoods with limited emphasis on conservation efforts. The intent of this report is to demonstrate the benefits of applying conservation design principles to the development of a conservation subdivision in rural Kansas.
A 132 acre tract of land, currently known as Nelson’s Ridge, is planned and designed for a subdivision development. The property is located just east of Manhattan, Kansas. The site includes a tributary drainage corridor surrounded by woodlands, existing agriculture fields and upland prairie. It is located no more than a mile from existing amenities of a growing residential and commercial corridor along Highway 24 in Pottawatomie County. The preliminary plat designed by local engineering firm Schwab-Eaton, demonstrates America’s typical or “conventional” approach to subdivision design (Arendt, 1996). The alternative approach is known as a low-impact development or “conservation development” (Gause 2007). After completing a thorough site inventory and analysis, two preliminary designs eventually led to a final conceptual master plan. The two preliminary designs included contemporary and neo-traditional schemes, each portraying conservation principles in alternative ways. Fully understanding the two design alternatives allowed for a balanced and more cohesive final design that incorporated the most positive aspects of both conservation approaches. The preliminary plat and the conservation design were then compared and analyzed in terms of demonstrated design principles and their economic feasibility.
This project provides an example for rural subdivision development in Pottawatomie County, Kansas. The project provides decision makers with a conceptual master plan for Nelson’s Ridge that implements conservation subdivision design principles. This project will educate developers, homeowners and the public about design alternatives for subdivision development. The comprehensive analysis of the proposed design will provide important insight into the benefits and limitations of implementing conservation principles into a development
Research Report: Prevalence and Mechanism of Atrazine Resistance in Waterhemp from Nebraska
Waterhemp is a troublesome summer annual broadleaf weed species that has evolved resistance to glyphosate and other herbicide sites of action (SOA) in Nebraska, including to groups 2 (i.e., Classic, Pursuit, FirstRate), 4 (i.e., 2, 4-D), 5(i.e., atrazine) and 27 (e.g., Callisto, Laudis). The overall objectives of this study were to Evaluate the eficay of PRE applied atrazine, metribuzin and sulfentrazone to control Nebraska waterhemp populations; Evaluate the efficacy of POST applied atrazine to control Nebraska waterhemp populations; and Determine the mechanism of atrazine resistance in Nebraska waterhemp populations
A Prospective Cohort of SARS-CoV-2-Infected Health Care Workers: Clinical Characteristics, Outcomes, and Follow-up Strategy
Background
During the coronavirus disease 2019 (COVID-19) outbreaks, health care workers (HCWs) are at a high risk of infection. Strategies to reduce in-hospital transmission between HCWs and to safely manage infected HCWs are lacking. Our aim was to describe an active strategy for the management of COVID-19 in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–infected HCWs and investigate its outcomes.
Methods
A prospective cohort study of SARS-CoV-2-infected health care workers in a tertiary teaching hospital in Barcelona, Spain, was performed. An active strategy of weekly polymerase chain reaction screening of HCWs for SARS-CoV-2 was established by the Occupational Health department. Every positive HCW was admitted to the Hospital at Home Unit with daily assessment online and in-person discretionary visits. Clinical and epidemiological data were recorded.
Results
Of the 590 HCWs included in the cohort, 134 (22%) were asymptomatic at diagnosis, and 15% (89 patients) remained asymptomatic during follow-up. A third of positive cases were detected during routine screening. The most frequent symptoms were cough (68%), hyposmia/anosmia (49%), and fever (41%). Ten percent of the patients required specific treatment at home, while only 4% of the patients developed pneumonia. Seventeen patients required a visit to the outpatient clinic for further evaluation, and 6 of these (1%) required hospital admission. None of the HCWs included in this cohort required intensive care unit admission or died.
Conclusions
Active screening for SARS-CoV-2 among HCWs for early diagnosis and stopping in-hospital transmission chains proved efficacious in our institution, particularly due to the high percentage of asymptomatic HCWs. Follow-up of HCWs in Hospital at Home units is safe and effective, with low rates of severe infection and readmission
Predicting the Trajectory of a Relativistic Electron Beam for External Injection in Plasma Wakefields
We use beam position measurements over the first part of the AWAKE electron
beamline, together with beamline modeling, to deduce the beam average momentum
and to predict the beam position in the second part of the beamline. Results
show that using only the first five beam position monitors leads to much larger
differences between predicted and measured positions at the last two monitors
than when using the first eight beam position monitors. These last two
positions can in principle be used with ballistic calculations to predict the
parameters of closest approach of the electron bunch with the proton beam. In
external injection experiments of the electron bunch into plasma wakefields
driven by the proton bunch, only the first five beam position monitors
measurements remain un-affected by the presence of the much higher charge
proton bunch. Results with eight beam position monitors show the prediction
method works in principle to determine electron and proton beams closest
approach within the wakefields width (1\,mm), corresponding to injection of
electrons into the wakefields. Using five beam position monitors is not
sufficient.Comment: seven pages, five figures, submitted for EAAC 2019 Proceeding
Cytokine Response to Traditional and Cluster Sets in Resistance-trained Women
Resistance exercise that incorporates intra-set rest between repetition blocks (i.e., cluster sets [CS]) can produce a smaller metabolic stress and endocrine response than traditional sets (TS). PURPOSE: To examine the effect of CS on the acute cytokine response in resistance trained women. METHODS: 12 resistance-trained women (mean ± SE; 23.7 ± 1.1 years; 160.1 ± 1.5 cm; 62.5 ± 1.7 kg; 5 ± 1 years training) completed 3 sessions in the follicular phase. One-repetition maximum (1RM) back squat (BS) (98.7 ± 4.1 kg), and BS:body mass (1.6 ± 0.1) were determined in Session 1. For Session 2 (3 days post Session 1) and Session 3 (7 days post Session 2), subjects were randomly assigned to either 4 sets of 10 reps with 120 seconds (s) inter-set rest (TS) or 4 x (2 x 5 reps) with 30s intra-set rest and 90s inter-set rest (CS). All performed both protocols at 70% 1RM BS. Instructions were to perform every rep “as explosively as possible”. Blood was collected pre-exercise (PRE), immediately after sets 1, 2, 3, 4 (IP), and at 5 (+5), 15 (+15), 30 (+30), and 60 (+60) min post-exercise and analyzed for interleukin (IL)-1β, IL-2, IL-6, IL-8, IL 10, and IL-15. Data were analyzed using repeated measures ANOVAs (2 × 9). RESULTS: A significant main effect of time (p\u3c0.05) was found for IL-1β, IL-2, IL-8, IL-10, and IL-15. Concentration of IL-1β was smaller at +5 (3.9 ± 0.4 ng/mL), +15 (3.6 ± 0.4) +30 (3.5 ± 0.3), and +60 (3.7 ± 0.4) compared to IP (4.1 ± 0.4). IL-2 was greater after set 1 (10.8 ± 1.0 ng/mL), and set 2 (11.0 ± 1.2) compared to PRE (10.2 ± 1.0), and smaller at +30 (9.9 ± 1.0) compared to IP (11.0 ± 1.0). IL-8 was greater after set 1 (8.4 ± 0.6 ng/mL), set 2 (8.6 ± 0.7), and set 3 (8.5 ± 0.7) compared to PRE (8.0 ± 0.6). IL-10 was smaller at +30 (31.3 ± 7.4 ng/mL) compared to PRE (34.0 ± 7.4), and also smaller at +15 (32.6 ± 7.9) +30 (31.3 ± 7.4), and +60 (33.4 ± 8.6) compared to IP (38.0 ± 8.6). IL-15 was greater at IP (15.5 ± 4.0 ng/mL) compared to PRE (13.4 ± 3.5), and smaller at PRE (13.4 ± 3.5), +30 (11.9 ± 3.3), and +60 (11.6 ± 3.2) compared to IP (15.5 ± 4.0). No condition × time point effects were observed. CONCLUSION: Both TS and CS induced an acute cytokine response in resistance-trained women; incorporating intra-set rest (CS) did not appear to affect this cytokine response
Non-Specific Antibodies Induce Lysosomal Activation in Atlantic Salmon Macrophages Infected by Piscirickettsia salmonis
Piscirickettsia salmonis, an aggressive intracellular pathogen, is the etiological agent of salmonid rickettsial septicemia (SRS). This is a chronic multisystemic disease that generates high mortalities and large losses in Chilean salmon farming, threatening the sustainability of the salmon industry. Previous reports suggest that P. salmonis is able to survive and replicate in salmonid macrophages, inducing an anti-inflammatory environment and a limited lysosomal response that may be associated with host immune evasion mechanisms favoring bacterial survival. Current control and prophylaxis strategies against P. salmonis (based on the use of antibiotics and vaccines) have not had the expected success against infection. This makes it urgent to unravel the host-pathogen interaction to develop more effective therapeutic strategies. In this study, we evaluated the effect of treatment with IgM-beads on lysosomal activity in Atlantic salmon macrophage-enriched cell cultures infected with P. salmonis by analyzing the lysosomal pH and proteolytic ability through confocal microscopy. The impact of IgM-beads on cytotoxicity induced by P. salmonis in infected cells was evaluated by quantification of cell lysis through release of Lactate Dehydrogenase (LDH) activity. Bacterial load was determined by quantification of 16S rDNA copy number by qPCR, and counting of colony-forming units (CFU) present in the extracellular and intracellular environment. Our results suggest that stimulation with antibodies promotes lysosomal activity by lowering lysosomal pH and increasing the proteolytic activity within this organelle. Additionally, incubation with IgM-beads elicits a decrease in bacterial-induced cytotoxicity in infected Atlantic salmon macrophages and reduces the bacterial load. Overall, our results suggest that stimulation of cells infected by P. salmonis with IgM-beads reverses the modulation of the lysosomal activity induced by bacterial infection, promoting macrophage survival and bacterial elimination. This work represents a new important evidence to understand the bacterial evasion mechanisms established by P. salmonis and contribute to the development of new effective therapeutic strategies against SRS
A Prospective Cohort of SARS-CoV-2-Infected Health Care Workers: Clinical Characteristics, Outcomes, and Follow-up Strategy
Background. During the coronavirus disease 2019 (COVID-19) outbreaks, health care workers (HCWs) are at a high risk of infection. Strategies to reduce in-hospital transmission between HCWs and to safely manage infected HCWs are lacking. Our aim was to describe an active strategy for the management of COVID-19 in severe acute respiratory syndrome coronavirus 2 (SARSCoV-2)-infected HCWs and investigate its outcomes. Methods. A prospective cohort study of SARS-CoV-2-infected health care workers in a tertiary teaching hospital in Barcelona, Spain, was performed. An active strategy of weekly polymerase chain reaction screening of HCWs for SARS-CoV-2 was established by the Occupational Health department. Every positive HCW was admitted to the Hospital at Home Unit with daily assessment online and in-person discretionary visits. Clinical and epidemiological data were recorded. Results. Of the 590 HCWs included in the cohort, 134 (22%) were asymptomatic at diagnosis, and 15% (89 patients) remained asymptomatic during follow-up. A third of positive cases were detected during routine screening. The most frequent symptoms were cough (68%), hyposmia/anosmia (49%), and fever (41%). Ten percent of the patients required specific treatment at home, while only 4% of the patients developed pneumonia. Seventeen patients required a visit to the outpatient clinic for further evaluation, and 6 of these (1%) required hospital admission. None of the HCWs included in this cohort required intensive care unit admission or died. Conclusions. Active screening for SARS-CoV-2 among HCWs for early diagnosis and stopping in-hospital transmission chains proved efficacious in our institution, particularly due to the high percentage of asymptomatic HCWs. Follow-up of HCWs in Hospital at Home units is safe and effective, with low rates of severe infection and readmission. Keywords. coronavirus; COVID-19; health care workers; Hospital at Home; SARS-CoV-2
Dendrotoxin-Îş suppresses tumor growth induced by human lung adenocarcinoma A549 cells in nude mice
Voltage-gated K+ (Kv) channels have been considered to be a regulator of membrane potential and neuronal excitability. Recently, accumulated evidence has indicated that several Kv channel subtypes contribute to the control of cell proliferation in various types of cells and are worth noting as potential emerging molecular targets of cancer therapy. In the present study, we investigated the effects of the Kv1.1-specific blocker, dendrotoxin-Îş (DTX-Îş), on tumor formation induced by the human lung adenocarcinoma cell line A549 in a xenograft model. Kv1.1 mRNA and protein was expressed in A549 cells and the blockade of Kv1.1 by DTX-Îş, reduced tumor formation in nude mice. Furthermore, treatment with DTX-Îş significantly increased protein expression of p21Waf1/Cip1, p27Kip1, and p15INK4B and significantly decreased protein expression of cyclin D3 in tumor tissues compared to the control. These results suggest that DTX-Îş has anti-tumor effects in A549 cells through the pathway governing G1-S transition
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