Range uncertainty in proton therapy has a significant impact on the utilization and efficacy of the treatment modality. Several methods are under investigation to verify proton range by the detection ...of secondary emissions, with many studies focused on the use of prompt gamma-ray imaging (PGI) as a means to determine the Bragg peak location. This work introduces a new system and method of PGI using a multi-knife-edge slit collimator and detector. Initial measurements using 50 MeV protons demonstrated the ability of the system to provide 2-dimensional prompt gamma-ray (PG) distributions. A Bragg peak localization precision of 1 mm (2σ) was achieved with delivery of (1.7 ± 0.8) x 10 8 protons into a PMMA target from an 8 cm standoff distance, suggesting the ability of the system to detect relative shifts in proton range while delivering fewer protons than used in a typical treatment fraction. Additionally, the absolute position of the Bragg peak was identified to within 1.6 mm (2σ) with 5.6 x 10 10 protons delivered. The initial results are promising and warrant further investigation and system optimization for clinical implementation.
Foregut contents of 56 specimens of Callinectes ornatus collected from Mullet Bay, Bermuda, in 1981 and 1988 were examined. Foreguts which were ≥ half full contained more prey items per gut (x = ...4.67) than did guts < half full ( x = 2.73). Dietary analysis was based on 2 methods: (1) the index of relative importance (IRI), which combined frequency of occurrence (FO), percentage of total biomass, and percentage of total numbers consumed, and (2) weighted points, which combined FO and estimated relative volumes of each prey item. No significant differences were revealed in relative proportions of foregut contents between males and females, or between adult and juvenile crabs. Modulus modulus, a cerithiacean gastropod mollusk, dominated the diet, accounting for 21.1 % of the total IRI. Two other cerithiaceans collectively ranked second (19.9% of total IRI). Carbonate substrate was the most frequently occurring category (51.79%) and ranked third in IRI (17.2% of total). Plant material, crustaceans, nereid polychaetes, fish, and bivalve mollusks ranked fourth through eighth in IRI. The validity of including carbonate substrate as a dietary component is discussed, as is the relative merit of the indices used in dietary analysis.
Morphometry, reproductive biology, diet, and epizoite infestation of Ovalipes stephensoni (Brachyura: Portunidae) are described. The results are based on observations of 347 specimens collected by ...demersal trawl on the continental shelf of the eastern United States from 13-198 m, between 28° and 37°N, and on 26 specimens from the National Museum of Natural History collections in Washington, D.C. All seven morphometric relationships observed (carapace length, body depth, propodal length, width and depth of crushing chela, and abdominal width) exhibited allometric growth to some extent. Sexual dimorphism was demonstrated for chelar propodal length and abdominal width. Prepubertal and pubertal molts were inferred from two changes in allometry of the male chelar propodal length and female abdominal width. Allometric maturity was correlated with gonad, pleopod, and gonopore development. Males reach full maturity at a carapace width of 61 mm; females complete maturation by the time they reach 51 mm in width. Ovalipes stephensoni is heterochelic and heterodontic with the crushing claw occurring on the right side in 91.6% of the specimens observed. There is little evidence that cheliped laterality changes with age (size). Although this species is an opportunistic carnivore, bivalve mollusks, cephalopods, and small crustaceans comprised the bulk of the diet. Relatively heavy infestations of lepadid barnacles, Octolasmis muelleri, were found in the branchial chamber. Lesions of the ciliated protozoan Synophrya hypertrophica were present in the gill lamellae.
1. Freezing point determinations were made on time blood of Crangon septemspinosa exposed to five salinities (15, 25, 30, 35, 45‰), at two temperatures (5, 15° C).
2. Sand shrimp, transferred acutely ...from 30‰ to either 15‰ or 45‰, experienced changes in hemolymph osmoconcentration which were related to the osmotic strength of the receiving medium. A time period of about 4 days was required for the shrimp to reach a new steady state at 5° C.
3. Crangon septemspinosa was observed to regulate its internal osmoconcentration to the extent that it was hyposmotic in normal seawater (30-35‰) and hyperosmotic in diluted seawater (15-25‰). In 45‰, adults were isosmotic but juveniles remained hyposmotic to the external medium.
4. There was no apparent temperature influence on the regulatory pattern of juvenile shrimp. Adults, however, exhibited high blood concentrations at 15° C than at 5° C. They were, in effect, regulating more effectively in diluted seawater and less effectively in normal seawater at the warmer temperature.
5. Osmoregulatory performance of C. septemspinosa was compared with that of the European species, C. crangon. Differences in the response to temperature between the species were discussed in terms of their geographic ranges and related temperature regimes.
ABSTRACT
A preliminary survey of 253 Ovalipes stephensoni collected off the southeast coast of the United States revealed a 94.5% incidence of infestation by the parasitic ciliate Synophrya ...hypertrophica. Analysis of 67 crabs indicated an infestation density ranging from 1 to 270 lesions per branchial chamber. An in depth study of 38 crabs (19 male, 19 female), ranging from 18 mm to 80 mm in carapace width (CW), provided details on the number of gill lamellae with and without parasitic lesions relative to size, sex, and branchial chamber of the crab. The mean lamellar counts of both chambers are not statistically different (P > 0.05), nor is there a significant difference in the mean count between males and females (P > 0.05). Significant differences in mean lamellar counts exist among the individual gills (ANOVA, P < 0.05), which can be ranked 1 (most anterior gill), 8, 2, 3, 7, 4, 6, 5 according to increasing number of lamellae, using the Student-Newman-Keuls test. The number of lamellae increases with body size (Y = 1,979 + 18.47 CW, r2 = 0.83, P < 0.001), but the relationship of the total lamellar count/mm CW with body size is allometric (log Y = 3.024 – 0.738 log CW, r2 = 0.96). The number of lamellae with lesions also increases with crab size (Y = 40.97 + 3.238 CW, r2 = 0.42, P < 0.05). However, there is no difference among the gills with respect to the density of infestation (ANOVA, P > 0.05). The lesions are distributed evenly among the gills (ANOVA, P > 0.05). The extent of the loss of respiratory surface area due to the presence of parasitic lesions was quantified by measuring the area of lesion and total lamellar surface of 45 parasite-laden lamellae of a 55.3 mm CW crab. Distal lamellae are subject to a significantly greater loss of lamellar tissue due to infestation (ANOVA, P < 0.01). The loss of respiratory surface resulting from three levels of infestation (light, medium, heavy) was extrapolated. The resultant percentage losses (0.05, 0.85, 1.39) are low and of questionable importance in the overall natural mortality of the host species.
Nuclear Scene Data Fusion (SDF), implemented in the Localization and Mapping Platform (LAMP) fuses three-dimensional (3D), real-time volumetric reconstructions of radiation sources with contextual ...information (e.g. LIDAR, camera, etc.) derived from the environment around the detector system. This information, particularly when obtained in real time, may be transformative for applications, including directed search for lost or stolen sources, consequence management after the release of radioactive materials, or contamination avoidance in security-related or emergency response scenarios. 3D reconstructions enabled by SDF localize contamination or hotspots to specific areas or objects, providing higher resolution over larger areas than conventional 2D approaches, and enabling more efficient planning and response, particularly in complex 3D environments. In this work, we present the expansion of these gamma-ray mapping concepts to neutron source localization. Here we integrate LAMP with a custom \(Cs_2LiLa(Br,Cl)_6:Ce\) (CLLBC) scintillator detector sensitive to both gamma-rays and neutrons, which we dub Neutron Gamma LAMP (NG-LAMP). NG-LAMP enables simultaneous neutron and gamma-ray mapping with high resolution gamma-ray spectroscopy. We demonstrate the ability to detect and localize surrogate Special Nuclear Materials (SNM) in real-time and in 3D based on neutron signatures alone, which is critical for the detection of heavily shielded SNM, when gamma-ray signatures are attenuated. In this work, we show for the first time the ability to localize, in 3D and realtime, a neutron source in the presence of a strong gamma-ray source, simultaneous and spectroscopic localization of three gamma-ray sources and a neutron source, and finally the localization of a surrogate SNM source based on neutron signatures alone, where gamma-ray data are consistent with background.
Changes in weight and water content of the hepatopancreas and ovary of Crangon crangon are described in relation to body weight and ovarian development. Percentage of water content of the organs in ...relation to ovarian stage was determined for 43 females; organ wet weight data were obtained from another 137 animals. All stages of gonadal development (oogenesis, previtellogenesis, vitellogenesis, and depleted) were represented in the sample population of ovigerous, nonovigerous, and postovigerous females. The ovary and hepatopancreas progress through cycles of progressive and retrogressive changes in weight and volume which are characterized by a phase shift between the two organs. This resembles a Volterra-Lotka system, for which equations were derived. Wet weight of the ovary increases by 69% through previtellogenesis, and by 282% from pre- to secondary vitellogenesis. This represents an increase of 5.5% of body weight occupied by the ovary during development. The hepatopancreas nearly doubles in size from early oogonial development through previtellogenesis, but decreases markedly during vitellogenesis. The net result is an increase from a minimum value of 4% to a combined organ volume occupying 9.5% of total body weight when the ovary is full vitellogenic. Increase in ovarian mass during development is not due to water increase. Water content decreases from > 70% in immature ovaries to 46% in vitellogenic organs. The hepatopancreas also loses water, but to a lesser extent: from 73% in oogenic individuals to 67% in vitellogenic animals.
ABSTRACT
Changes in weight and water content of the hepatopancreas and ovary of Crangon crangon are described in relation to body weight and ovarian development. Percentage of water content of the ...organs in relation to ovarian stage was determined for 43 females; organ wet weight data were obtained from another 137 animals. All stages of gonadal development (oogenesis, previtellogenesis, vitellogenesis, and depleted) were represented in the sample population of ovigerous, nonovigerous, and postovigerous females. The ovary and hepatopancreas progress through cycles of progressive and retrogressive changes in weight and volume which are characterized by a phase shift between the two organs. This resembles a Volterra-Lotka system, for which equations were derived. Wet weight of the ovary increases by 69% through previtellogenesis, and by 282% from pre- to secondary vitellogenesis. This represents an increase of 5.5% of body weight occupied by the ovary during development. The hepatopancreas nearly doubles in size from early oogonial development through previtellogenesis, but decreases markedly during vitellogenesis. The net result is an increase from a minimum value of 4% to a combined organ volume occupying 9.5% of total body weight when the ovary is fully vitellogenic. Increase in ovarian mass during development is not due to water increase. Water content decreases from > 70% in immature ovaries to 46% in vitellogenic organs. The hepatopancreas also loses water, but to a lesser extent: from 73% in oogenic individuals to 67% in vitellogenic animals.
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