Holographic particle detection

The feasibility was studied of developing a novel particle track detector based on the detection of 1p-1s emission radiation from electron bubbles in liquid helium. The principles, design, construction, and initial testing of the detection system have been described in previous reports. The main obstacle encountered was the construction of the liquid-helium tight infrared windows. Despite numerous efforts in testing and redesigning the windows, the problem of window leakage at low temperature persisted. Due to limited time and resources, attention was switched to investigating the possibility of using room-temperature liquid as the detection medium. A possible mechanism was the detection of de-excitation radiation emitted from localized electrons in common liquids where electrons exhibit low mobilities, as suggested in the previous report. The purity of the liquid is critical in this method as the dissolved impurities (such as oxygen), even in trace amounts, will act as scavengers of electrons. Another mechanism is discussed whereby the formation of the superoxide ions by electron scavenging behavior of dissolved oxygen is exploited to detect the track of ionizing particles. An experiment to measure the ionization current produced in a liquid by a pulsed X-ray beam in order to study propertiies of the ions is also reported

A program to study antiprotons in the cosmic rays: Arizona collaboration

The Low Energy AntiProton (LEAP) experiment was designed to measure the primary antiproton flux in the 200 MeV to 1 GeV kinetic energy range. A superconducting magnetic spectrometer, a time-of-flight (TOF) detector, and a Cherenkov counter are the main components of LEAP. An additional scintillation detector was designed and constructed to detect the passage of particles through the bottom of the Cherenkov counter. The LEAP package was launched on August 22, 1987, and enjoyed a 27 hour flight, with 23 hours of data at high altitude. Preliminary plans for data analysis include using the Micro-Vax at the University of Arizona for data reduction of the Cherenkov and S2 signals

A program to study antiprotons in the cosmic rays: Arizona collaboration

The Cherenkov detector designed and built for the LEAP (Low Energy AntiProton) experiment utilized a novel design to achieve appreciable sensitive area (02. sq m) with a refractive index of 1.25 in a magnetic fringe field region (500-1000 Gauss). The weight was held to only 64 kg by using 16 unshielded Hamamatsu R2490-01 photomultiplier tubes, each aligned with its local magnetic field. A filling and reservoir system for the highly volatile FC-72 liquid Cherenkov radiator also presented many design challenges. Relativistic particles yielded about 72 photoelectrons, total

A Case Study of Attitudes and Perceptions of Leadership Characteristics as Perceived by Middle School Teachers and the Principals

This dissertation determined the congruence with the order of importance concerning what middle school teachers and middle school principals value regarding the behavioral characteristics of effective middle school principals and if a relationship exists between those characteristics and the 2006/2008 North Carolina Teacher Working Conditions Surveys. The indications and suggestions of this research were based on the data collected from many different middle schools representing different geographical areas within a large school system located within the piedmont-triad central region of North Carolina. Information was obtained from different multi-question surveys from middle school teachers and principals, open-ended questions, and focus group interviews. This component of the study identified any common behavioral characteristics that the teachers and principals, at the same school, have of themselves with an order of importance. This information was compared to the 2006 and 2008 results of the North Carolina Teacher Working Conditions Surveys information from the same middle schools to determine if a correlation existed between the total data collected. The results of this research indicated that the younger teachers with less teaching experiences wanted their principal to have the traits of a manager and an instructional leader. The older teachers with more teaching experiences wanted their principal to have the traits of one who uses people skills and one who has a vision. The principals see themselves primarily as instructional leaders

Blood pressure management in ischemic stroke patients undergoing mechanical thrombectomy

The relationship between presenting blood pressure in acute ischemic stroke patients and outcome is complex. Several studies have demonstrated a U-shaped curve with worse outcomes when blood pressure is high or low. The American Heart Association/American Stroke Association guidelines recommend values of blood pressure \u3c 185/110 mmHg in patients treated with intravenous t-PA and permissive hypertension up to 220/120 mmHg in those not treated with intravenous t-PA. The optimal blood pressure target is less clear in patients undergoing mechanical thrombectomy. Before thrombectomy, the guidelines recommend a blood pressure \u3c 185/110 mmHg though patients with even lower systolic blood pressures may have better outcomes. During and after thrombectomy, the guidelines recommend a blood pressure \u3c 180/105 mmHg. However, several studies have suggested that during thrombectomy the primary goal should be to prevent significant low blood pressure (e.g., target systolic blood pressure \u3e 140 mmHg or MAP \u3e 70 mmHg). After thrombectomy, the primary goal should be to prevent high blood pressure (e.g., target systolic blood pressure \u3c 160 mmHg or MAP \u3c 90 mmHg). To make more specific recommendations, large, randomized-control studies are needed that address factors such as the baseline blood pressure, timing and degree of revascularization, status of collaterals, and estimated risk of reperfusion injury

Barefoot vs common footwear:A systematic review of the kinematic, kinetic and muscle activity differences during walking

Habitual footwear use has been reported to influence foot structure with an acute exposure being shown to alter foot position and mechanics. The foot is highly specialised thus these changes in structure/position could influence functionality. This review aims to investigate the effect of footwear on gait, specifically focussing on studies that have assessed kinematics, kinetics and muscle activity between walking barefoot and in common footwear. In line with PRISMA and published guidelines, a literature search was completed across six databases comprising Medline, EMBASE, Scopus, AMED, Cochrane Library and Web of Science. Fifteen of 466 articles met the predetermined inclusion criteria and were included in the review. All articles were assessed for methodological quality using a modified assessment tool based on the STROBE statement for reporting observational studies and the CASP appraisal tool. Walking barefoot enables increased forefoot spreading under load and habitual barefoot walkers have anatomically wider feet. Spatial-temporal differences including, reduced step/stride length and increased cadence, are observed when barefoot. Flatter foot placement, increased knee flexion and a reduced peak vertical ground reaction force at initial contact are also reported. Habitual barefoot walkers exhibit lower peak plantar pressures and pressure impulses, whereas peak plantar pressures are increased in the habitually shod wearer walking barefoot. Footwear particularly affects the kinematics and kinetics of gait acutely and chronically. Little research has been completed in older age populations (50+ years) and thus further research is required to better understand the effect of footwear on walking across the lifespan

A Happy Abundance : Tales, Memoirs and More Past and Present in Wayne, Maine

https://digitalmaine.com/wayne_books/1002/thumbnail.jp

Sharp Phylogeographic Breaks and Patterns of Genealogical Concordance in the Brine Shrimp Artemia franciscana

Genealogical concordance is a critical overlay of all phylogenetic analyses, irrespective of taxonomic level. To assess such patterns of congruence we have compiled and derived sequence data for two mitochondrial (16S rRNA, COI) and two nuclear (ITS1, p26) markers in 14 American populations of the hypersaline branchiopod Artemia franciscana. Cladistic analysis revealed three reciprocally monophyletic mitochondrial clades. For nuclear DNA, incomplete lineage sorting was evident presumably as a result of slower coalescence or male-mediated dispersal. Our findings capture the genealogical interval between gene splitting and population divergence. In this sense, strong indications are provided in favour of a superspecies status and ongoing speciation in A. franciscana