ABSTRACT
Energetic charged particle detectors characterize a portion of the plasma distribution function that plays critical roles in some physical processes, from carrying the currents in planetary ring currents to weathering the surfaces of planetary objects. For several low-resource missions in the past, the need was recognized for a low-resource but highly capable, mass-species-discriminating energetic particle sensor that could also obtain angular distributions without motors or mechanical articulation. This need led to the development of a compact Energetic Particle Detector (EPD), known as the "Puck" EPD (short for hockey puck), that is capable of determining the flux, angular distribution, and composition of incident ions between an energy range of ~10 keV to several MeV. This sensor makes simultaneous angular measurements of electron fluxes from the tens of keV to about 1 MeV. The same measurements can be extended down to approximately 1 keV/nucleon, with some composition ambiguity. These sensors have a proven flight heritage record that includes missions such as MErcury Surface, Space ENvironment, GEochemistry, and Ranging and New Horizons, with multiple sensors on each of Juno, Van Allen Probes, and Magnetospheric Multiscale. In this review paper we discuss the Puck EPD design, its heritage, unexpected results from these past missions and future advancements. We also discuss high-voltage anomalies that are thought to be associated with the use of curved foils, which is a new foil manufacturing processes utilized on recent Puck EPD designs. Finally, we discuss the important role Puck EPDs can potentially play in upcoming missions.
ABSTRACT
Red imported fire ants, Solenopsis invicta Buren, are adversely affected by phorid flies in the genus Pseudacteon by instigating defensive behaviors in their hosts, and in turn reducing the efficiency of S. invicta foraging. Multiple Pseudacteon species have been released in Texas, and research has been focused on the establishment and spread of these introduced biological control agents. Field experiments were conducted to determine bait particle size selection of S. invicta when exposed to phorid populations. Four different particle sizes of two candidate baits were offered to foragers (one provided by a pesticide manufacturer, and a laboratory-created bait). Foragers selectively were attracted to, and removed more 1-1.4-mm particles than any other bait size. The industry-provided bait is primarily made of particles in the 1.4-2.0 mm size, larger than what was selected by the ants in this study. While there was a preference for foragers to be attracted to and rest on the industry-provided blank bait, S. invicta removed more of the laboratory-created bait from the test vials. There was an abundance of workers with head widths ranging from 0.5-0.75 mm collected from baits. This was dissimilar from a previous study wherein phorid flies were not active and in which large workers were collected in higher abundance at the site. This implies that phorid fly activity caused a shift for red imported fire ant colonies to have fewer large foragers.
Subject(s)
Ants/physiology , Appetitive Behavior , Biological Control Agents , Particle Size , Animals , Ants/anatomy & histology , Chemotaxis , Diptera , Head/anatomy & histology , TexasABSTRACT
A variety of traps have been developed for monitoring introduced populations of Pseudacteon spp. phorid flies (Diptera: Phoridae) across their established range in the United States. Such traps typically exploit common aspects of phorid fly biology and behavior, such as their attraction to live or dead red imported fire ants, Solenopsis invicta Buren (Hymenoptera: Formicidae), as well as the perching behavior of these parasitoids. However, populations of multiple species of phorid flies have been established in the United States to serve as biological control agents against S. invicta, and it is unclear if all trap designs are equally effective in sampling this variety of phorid species. This study investigated the effectiveness of six trap designs simultaneously during three sampling events in south-central Texas. Interactions between two species of phorid flies (Pseudacteon tricuspis Borgmeier and P. curvatus B.) and their hosts have been intensively studied at this location for over eight years. When analyzed independently, there were no significant differences in the mean number of P. curvatus or P. tricuspis phorids collected by any of the trap designs during any of the sampling events. However, when the total number of phorids collected were combined, significant trap performance differentials were observed during the October 2010 sampling event. Furthermore, there were significant differences among male flies during the September 2012 observation. Additionally, a trap component cost comparison is provided. The consistent and relatively equivalent performance of the phorid traps investigated in these trials suggests that all are appropriate for phorid surveillance, and cost and ease-of-use considerations may be the most important criteria when selecting a trap design.
Subject(s)
Biological Control Agents , Diptera/physiology , Pheromones/pharmacology , Animals , Chemotaxis , Female , Male , Seasons , TexasABSTRACT
OBJECTIVE: Laboratory studies have documented a wide range of pesticide-induced changes in the hematopoietic and lymphoreticular systems. Some of these are expressed as altered serum values, blood cell counts, and leucocyte functions. The goal of the present study was to determine whether these alterations were evident in peripheral blood of Nebraska farmers who applied pesticides to their fields. METHODS: An invitation to participate was mailed to 100 residents (70 farmers; 30 controls) of Butler County, Nebraska. All respondents (51 farmers and 21 controls) were enrolled and surveyed by written questionnaire for health status and pesticide use. Our analysis included 45 farmers and 18 controls. The farmers were divided into a high (n = 23) and a low (n = 22) pesticide use group. Statistical correlations of ten blood values with both pesticide use and age were evaluated, since pesticide use correlated with age. RESULTS: Four of the ten blood values correlated with pesticide use and age (Spearman Rho). In a multiple regression model, pesticide use (not age) proved to be a predictor of red blood cell count and hematocrit. In the same model, pesticide use was not a predictor of mean red cell volume or candida antigen-induced T-lymphocyte proliferation. Serum complement activity did not correlate with pesticide use among the farmers (n = 45) but was significantly reduced (ANOVA) in the high pesticide use group, compared to controls. CONCLUSIONS: A preliminary study of blood values in a small cohort of Nebraska farmers found no pesticide-associated effects on 1) leucocyte count, 2) antigen- and mitogen-stimulated T-cell proliferation, 3) mitogen-stimulated B-cell proliferation, and 4) concentrations of serum IgG and IgM. The study found small but statistically significant pesticide-associated effects on red blood cells and serum complement.
Subject(s)
Agriculture , Blood Cells/drug effects , Immune System/drug effects , Occupational Diseases/chemically induced , Occupational Exposure/adverse effects , Pesticides/adverse effects , Adult , Aged , Cohort Studies , Hematocrit , Humans , Immunoglobulins/drug effects , Lymphocyte Activation , Lymphocytes/drug effects , Male , Middle Aged , Nebraska , Occupational Diseases/bloodSubject(s)
Carotid Artery Injuries , Wounds, Nonpenetrating/diagnosis , Carotid Arteries/diagnostic imaging , Carotid Arteries/pathology , Carotid Artery Thrombosis/diagnosis , Carotid Artery Thrombosis/etiology , Carotid Artery Thrombosis/therapy , Humans , Magnetic Resonance Angiography , Prognosis , Tomography, X-Ray Computed , Treatment Outcome , Wounds, Nonpenetrating/complications , Wounds, Nonpenetrating/etiology , Wounds, Nonpenetrating/therapyABSTRACT
OBJECTIVE: Using CT to grade blunt splenic injuries frequently does not predict clinical outcome. This retrospective, blinded study evaluated whether revealing a traumatic pseudoaneurysm or frank hemorrhage on an initial CT examination can be used to predict the successful clinical outcome of patients managed without surgery. MATERIALS AND METHODS: The medical and CT records of all patients with blunt splenic injury during a 5-year period were independently reviewed for vascular abnormalities. Also, the grade of injury was reconfirmed. Hemodynamically stable patients with injuries of grades 1-3 were managed without surgery. Clinical failure occurred if a patient required splenectomy or splenorrhaphy after any attempt of nonsurgical management. RESULTS: Two hundred sixty-three patients were treated for blunt splenic injuries. Eighty-two of these patients underwent emergent surgery on the basis of clinical and peritoneal lavage findings without CT examination. The remaining 181 (69%) patients were initially evaluated with emergent abdominal CT. Of these 181 patients, 72 (40% of those undergoing CT) were treated nonsurgically. Nonsurgical therapy failed in 11 (15%) of these 72 patients. Of these 11 patients, nine (82%) had a defined vascular abnormality of the spleen. Only eight (13%) of the remaining 61 patients who underwent CT and successful nonsurgical management had a vascular abnormality of the spleen. CONCLUSION: The failure rate in patients with nonsurgically managed blunt splenic injuries may be markedly reduced if patients with traumatic pseudoaneurysm or active hemorrhage revealed on emergent CT are treated with early surgical or endovascular repair.
Subject(s)
Spleen/injuries , Tomography, X-Ray Computed , Wounds, Nonpenetrating/diagnostic imaging , Adult , Emergencies , Female , Humans , Male , Predictive Value of Tests , Retrospective Studies , Spleen/blood supply , Spleen/diagnostic imaging , Trauma Severity Indices , Treatment Failure , Treatment Outcome , Wounds, Nonpenetrating/therapyABSTRACT
OBJECTIVE: Emergent aortography is commonly used to confirm and define a suspected thoracic aortic rupture detected by CT screening. We evaluated whether helical CT aortography can replace transcatheter aortography for critically injured patients. SUBJECTS AND METHODS: Over 22 months, 38 thoracic aorta and great vessel injuries were detected in 3229 patients with nontrivial blunt chest trauma who underwent helical CT screening. Planar, oblique, and curved two-dimensional reconstructions and three-dimensional shaded-surface display and maximum intensity projection volume-rendering techniques were used to evaluate the aortic injuries. Transcatheter aortography or surgery was performed in all stable patients. RESULTS: Twenty-eight of the injuries involved the descending thoracic aorta. All such injuries were best identified on axial images before CT angiography. CT angiography adequately showed tears over 15 mm long. Smaller tears required axial images for corroboration. CONCLUSION: Technically adequate axial helical CT detects and defines all injuries of the thoracic aorta. CT angiography supplements the conventional examination and can replace transcatheter aortography except for small tears or indeterminate studies.
Subject(s)
Aorta, Thoracic/diagnostic imaging , Aortic Rupture/diagnostic imaging , Tomography, X-Ray Computed , Adolescent , Adult , Aged , Aorta, Thoracic/injuries , Aortic Rupture/etiology , Female , Humans , Image Processing, Computer-Assisted , Male , Middle Aged , Thoracic Injuries/complications , Wounds, Nonpenetrating/complicationsABSTRACT
PURPOSE: To determine the effectiveness of helical computed tomography (CT) as a screening device to detect traumatic aortic rupture. MATERIALS AND METHODS: Helical CT was used to examine 1,518 patients with nontrivial blunt trauma. Of these patients, 127 (8.37%) with abnormal CT scans of the mediastinum or aorta underwent thoracic aortography--89 patients solely for evaluation of mediastinal hematoma depicted at CT. Imaging abnormalities were correlated with surgical or clinical outcome. RESULTS: Twenty-one aortic injuries were identified that ranged from subtle intimal flaps to complete aortic disruption. Helical CT was more sensitive than aortography (100% versus 94.4%, respectively) but less specific (81.7% versus 96.3%, respectively) in detection of aortic injuries in patients who underwent both examinations. The association between CT findings and outcome was phi = 0.62 (chi2 = 49.1, 1 df, P < .01) and between aortography and outcome was phi = 0.85 (chi2 = 92.2, 1 df, P < .001). The P value of the difference between the phi coefficients was .10. CONCLUSION: Helical CT of the chest is effective for screening critically injured patients with possible blunt thoracic aortic injuries.
Subject(s)
Aortic Rupture/diagnostic imaging , Tomography, X-Ray Computed , Adolescent , Adult , Aged , Aged, 80 and over , Aortography , Female , Guidelines as Topic , Humans , Male , Middle Aged , Radiography, Thoracic , Wounds, Nonpenetrating/diagnostic imagingABSTRACT
The heliosphere instrument for spectrum, composition, and anisotropy (HISCALE) recorded the fluxes of low-energy ions and electrons (> 50 kiloelectron volts) when Ulysses crossed the southern solar polar region and revealed that the large-scale structure of the heliosphere to at least approximately -75 degrees was significantly influenced by the near-equatorial heliospheric current sheet. Electrons in particular were accelerated by the current sheet-produced and poleward-propagating interplanetary reverse shock at helioradii far from the Ulysses location. At heliolatitudes higher than approximately -75 degrees on the Ulysses ascent to the pole and approximately -50 degrees on the descent, small, less regular enhancements of the lowest energy electron fluxes were measured whose relations to the current sheet were less clear. The anomalous component of low-energy (approximately 2 to 5 megaelectron volts per nucleon) oxygen flux at the highest heliolatitudes was found to be approximately 10(-8) [per square centimeter per second per steradian (per kiloelectronvolt per nucleon)]; the anomalous Ne/O ratio was approximately 0.25.
Subject(s)
Extraterrestrial Environment , Solar System , Electrons , Ions , Oxygen , SpacecraftABSTRACT
PURPOSE: Adhesive capsulitis involving the glenohumeral joint (frozen shoulder) is an insidious and painful condition that results in gradual loss of joint motion. Recovery is frequently prolonged despite multiple therapeutic maneuvers. The authors investigate the mechanism of action and the long-term clinical result of distention arthrography for the treatment of patients with frozen shoulder. PATIENTS AND METHODS: Sixteen patients with adhesive capsulitis of the shoulder were treated with therapeutic capsular distention by using intra-articular injection of a 30-mL mixture of lidocaine, corticosteroid, and contrast media immediately following diagnostic arthrography. RESULTS: Capsular disruption was demonstrated in all cases. Thirteen patients (80%) experienced immediate pain relief and increased shoulder mobility. This improvement was maintained over a follow-up interval of 6 months or more. Disruption occurred at the subscapular bursa in eight patients, the subacromial bursa in six, and the distal bicipital tendon sheath in two. These latter two patients had no pain relief. CONCLUSION: Arthrographic distention of the constricted capsule appears to be an excellent therapeutic intervention for achieving rapid symptomatic relief from adhesive capsulitis.
Subject(s)
Joint Capsule/diagnostic imaging , Periarthritis/therapy , Shoulder Joint/diagnostic imaging , Arthrography/methods , Contrast Media/administration & dosage , Female , Humans , Injections, Intra-Articular , Joint Capsule/drug effects , Lidocaine/administration & dosage , Male , Methylprednisolone/administration & dosage , Middle Aged , Periarthritis/diagnostic imaging , Periarthritis/epidemiology , Physical Therapy Modalities , Prospective Studies , Range of Motion, Articular/physiology , Shoulder Joint/physiopathologySubject(s)
Electron Transport Complex III/antagonists & inhibitors , Fungicides, Industrial/toxicity , Oximes/toxicity , Phenyl Ethers/toxicity , Antifungal Agents/chemistry , Antifungal Agents/toxicity , Fatty Acids, Unsaturated/chemistry , Fatty Acids, Unsaturated/toxicity , Fungi/drug effects , Fungicides, Industrial/chemistry , Methacrylates , Molecular Structure , Oximes/chemistry , Phenyl Ethers/chemistry , Strobilurins , Structure-Activity RelationshipABSTRACT
Microclimatic and vegetative effects on the population size and activity patterns of larval Eutrombicula alfreddugesi Oudemans, 1910 (Acari: Trombiculidae), were investigated in Nebraska between latitude 40 degrees 0'0" N and 40 degrees 1'21" N. Larval population densities along a forest edge were greatest in areas of high relative humidity, moderate temperature, low incident sunlight, and increasing substrate vegetation. Although chigger populations existed throughout the forest edge, larger populations concentrated in short- to tall-grass transition zones. Chiggers were rarely found in the undergrowth beneath the tree canopy. Chigger activity correlated with a microclimatically driven diurnal rhythm. Activity was greatest during the late afternoon-early evening, between 1530 and 1930 hours (CDST). Larval activity dropped to low levels and remained so until sunrise; this period of reduced activity occurred between 1930 and 0530 hours. Small increases in larval activity occurred around sunrise (approximately 0600-0700 hours). Between about 0700 and 1530 hours, larval E. alfreddugesi were inactive and did not respond to normal sampling stimuli. Larval populations appeared in late April through early May, peaked in abundance in late June and early July, diminished through late summer, and disappeared in midautumn as the ground began to freeze.
Subject(s)
Circadian Rhythm , Ecology , Trombiculidae/physiology , Animals , Nebraska , Poaceae , SeasonsABSTRACT
The potency of the anticholinesterase (antiCHE) insecticides as serine hydrolase inhibitors, and evidence for serine hydrolase activity in interleukin-2 (IL2) signalling suggest that the natural killer (NK) cell may be a target for dysregulation by antiCHE insecticides. NK cells are large granular lymphocytes (LGL) that respond to IL2 by proliferating and increasing their cytolytic efficiency. In the present study, we assessed the effects of carbaryl (CA, an antiCHE insecticide) and alpha-naphthol (NA, the major metabolite of CA) on both target cell killing per se and IL2 enhancement of target cell killing by human NK cells. Human LGL, collected from the peripheral blood of normal donors, were cultured for 4 days with human recombinant IL2 (HRIL2), then assayed by a 51Chromium (51Cr) release assay for lytic activity against human K562 cells. When added at the beginning of the culture period, CA inhibited enhancement of cytolytic efficiency in a concentration-dependent manner; at concentrations (0.5 and 5.0 microM) compatible with no cholinergic toxicity. Reduction of the effector/target cell (E/T) ratio in the 51Cr release assay markedly enhanced the observed inhibition by CA. In one experiment, inhibition increased from 6% to 20%, 17% to 35%, and 53% to 73% at 0.5, 5.0, and 50 microM CA, respectively, when E/T was reduced from 10:1 to 2.5:1. This result is consistent with reduced cytolytic efficiency of individual NK cells exposed to CA. NA had no effect at 0.5 or 5.0 microM but caused some inhibition at 50 microM. Neither CA nor NA produced LGL death. When CA or NA was added directly to the 51Cr release assay, inhibition was not observed. The mechanism of inhibition of IL2-stimulated enhancement of target cell killing is not yet known, however, the results are consistent with impairment of IL2 signalling, by CA.
Subject(s)
Carbaryl/toxicity , Interleukin-2/immunology , Killer Cells, Natural/drug effects , Adult , Carbaryl/metabolism , Cell Death , Cells, Cultured , Humans , Killer Cells, Natural/immunology , Lymphocyte Activation , Male , Naphthols/metabolism , Recombinant Proteins/immunologyABSTRACT
Splenomegaly associated with myelodysplastic disorders in children may be massive and can result in pancytopenia, abdominal discomfort, and respiratory distress. When these symptoms cannot be relieved by nonsurgical means, splenectomy may be indicated. Under such conditions, surgical splenectomy carries increased risks, as the thrombocytopenia is difficult to correct secondary to splenic sequestration. Additionally, the surgical anatomy is often distorted secondary to the massive spleen and dissection can be difficult. These factors can lead to uncontrollable hemorrhage. In an attempt to decrease intraoperative blood loss, the authors successfully performed preoperative splenic artery embolization in 11 of 12 children (age range, 1-11 years) with pancytopenia due to hypersplenism. Hypersplenism requiring surgical splenectomy was due to leukemia (n = 9), myelodysplastic syndrome (n = 1), immune thrombocytopenia (n = 1), and osteopetrosis (n = 1). Embolization was performed under general anesthesia, prior to surgery, with gelatin sponge particles alone, Gianturco coils alone, or a combination of polyvinyl alcohol sponge particles and Gianturco coils. Embolization allowed for safe surgical splenectomy.
Subject(s)
Embolization, Therapeutic , Hypersplenism/surgery , Spleen , Splenectomy , Child , Child, Preschool , Humans , Hypersplenism/etiology , Infant , Leukemia/complications , Myelodysplastic Syndromes/complications , Osteopetrosis/complications , Preoperative Care , Thrombocytopenia/complicationsABSTRACT
Measurements of the hot plasma environment during the Ulysses flyby of Jupiter have revealed several new discoveries related to this large rotating astrophysical system. The Jovian magnetosphere was found by Ulysses to be very extended, with the day-side magnetopause located at approximately 105 Jupiter radii. The heavy ion (sulfur, oxygen, and sodium) population in the day-side magnetosphere increased sharply at approximately 86 Jupiter radii. This is somewhat more extended than the "inner" magnetosphere boundary region identified by the Voyager hot plasma measurements. In the day-side magnetosphere, the ion fluxes have the anisotropy direction expected for corotation with the planet, with the magnitude of the anisotropy increasing when the spacecraft becomes more immersed in the hot plasma sheet. The relative abundances of sulfur, oxygen, and sodium to helium decreased somewhat with decreasing radial distance from the planet on the day-side, which suggests that the abundances of the Jupiter-derived species are dependent on latitude. In the dusk-side, high-latitude region, intense fluxes of counter-streaming ions and electrons were discovered from the edge of the plasma sheet to the dusk-side magnetopause. These beams of electrons and ions were found to be very tightly aligned with the magnetic field and to be superimposed on a time- and space-variable isotropic hot plasma background. The currents carried by the measured hot plasma particles are typically approximately 1.6 x 10(-4) microamperes per square meter or approximately 8 x 10(5) amperes per squared Jupiter radius throughout the high-latitude magnetosphere volume. It is likely that the intense particle beams discovered at high Jovian latitudes produce auroras in the polar caps of the planet.
ABSTRACT
Larvae of the pest chigger mite Eutrombicula alfreddugesi Oudemans, 1910, exhibited a low repellent threshold for N,N-diethyl-3-methylbenzamide (deet) in a field setting. Use of a deet-based repellent significantly reduced chigger mite infestation. Efficacy of aerosol formulations was significantly diminished with 9% (AI) deet. E. alfreddugesi utilized both direct and indirect paths to infest the human body. Direct infestation led to the highest body region bite counts. Distribution of E. alfreddugesi bites over 15 regions of the human body fell into three zones of decreasing parasitism: the ankle/calf region (accessed through direct infestation); the groin, chest, back, armpits, and feet (accessed through indirect infestation); and the thighs, arms, buttocks, head, and neck, which were infrequently attacked or were unavailable to E. alfreddugesi.
Subject(s)
DEET , Insect Bites and Stings/prevention & control , Mites , Animals , Humans , LarvaABSTRACT
Research was conducted to assess dermal and respiratory exposure to applicators from chlordane and heptachlor used for subterranean termite control and exposure to residents of treated homes. Dermal exposure of 29 applicators was evaluated by using gauze pads attached to outer and inner clothing at selected body regions. Respiratory exposure of applicators was monitored with personnel-type air samplers worn during application periods. Air samplers were equipped with polyurethane foam plugs to trap airborne chlordane and heptachlor. Exposure of residents was measured by sampling ambient air of 19 homes treated with the termiticides. Electric air samplers equipped with foam plugs were used to monitor ambient air from the basement, the kitchen, and one bedroom at: 24 h prior to termiticide application, during application, and post-application at 24 h, 1 wk, and monthly for 6 mo. Applicator dermal exposure was estimated based on exposure rates to each body region. Respiratory exposure was estimated based on termiticide concentrations in the air and on the ventilation rate of a person doing light work. Residents' exposure was estimated based on the amount of termiticide present in ambient air. Results indicated that applicator exposure rates to chlordane and heptachlor were 2.54 and 1.88 micrograms/kg/h, respectively. Residents were exposed to less than 0.69 and 2.86 micrograms/m3 of chlordane and heptachlor, respectively. During this research, the application of termiticide containing chlordane and heptachlor posed minimal risk in terms of acute exposure to either the applicators or the residents of the treated homes.
Subject(s)
Air Pollution, Indoor/analysis , Chlordan/analysis , Heptachlor/analysis , Insect Control/methods , Chlordan/administration & dosage , Heptachlor/administration & dosage , Humans , Skin AbsorptionABSTRACT
Bronchial arteriography and embolotherapy were performed to control hemoptysis in 11 patients with advanced stages of cystic fibrosis. Two patients suffered massive, 1 moderate, and 8 mild but recurrent hemoptysis. The embolization procedures were performed with Gelfoam, Ivalon, and coils in one to four separate procedures. Altogether, 19 of 20 procedures were successful, with follow-up periods ranging from 9 months to 8 years. No serious complications were encountered except for one femoral artery pseudoaneurysm which required surgical repair. Rapid digital subtraction angiography and "roadmapping" were considered helpful in avoiding the complication of reflux embolization and expediting the procedures. Bronchial embolization is a life-saving procedure for severe hemoptysis in patients with cystic fibrosis and is considered safe enough to include the indications of moderate and mild/recurrent hemoptysis to improve the quality of life in these patients.