Characterization of the Hamamatsu S8664 Avalanche Photodiode for X-Ray and VUV-light detection

We present the first operation of the Avalanche Photodiode (APD) from Hamamatsu to xenon scintillation light and to direct X-rays of 22.1 keV and 5.9 keV. A large non-linear response was observed for the direct X-ray detection. At 415 V APD bias voltage it was of about 30 % for 22.1 keV and about 45 % for 5.9 keV. The quantum efficiency for 172 nm photons has been measured to be 69 +/- 15 %.Comment: 11 pages, 3 figures, submitted to Elsevie

Variation in Mating Dynamics across Five Species of Leiobunine Harvestmen (Arachnida: Opliones)

The study of mating choices often focuses on correlates of traits to the overall outcome of a mating interaction. However, mating interactions can proceed through a series of stages, with opportunities for assessment at each stage. We compared whether male or female size predicted mating interaction outcome across several stages of mating in five species of North American leiobunine harvestmen (commonly known as daddy longlegs). Leiobunine harvestmen have been previously shown to exhibit incredible morphological diversity consistent with a spectrum of male–female antagonism. Across all of the species, we found a general progression of female size predicting the outcome (success and timing) of early stages of interactions, and male size or male size relative to female size predicting the outcome and timing of later stages of interactions. We also found that size was not a strong predictor of outcome in the two species on the lower end of the antagonism spectrum. The variation in how female and male size predicted outcomes across species and stages of mating suggests that multiple mechanisms may operate to shape mating dynamics within and across species. Given the close relatedness of the species studied, the patterns we uncovered suggest a rapid evolution of the traits and processes predicting the outcome of mating interactions

A gamma- and X-ray detector for cryogenic, high magnetic field applications

As part of an experiment to measure the spectrum of photons emitted in beta-decay of the free neutron, we developed and operated a detector consisting of 12 bismuth germanate (BGO) crystals coupled to avalanche photodiodes (APDs). The detector was operated near liquid nitrogen temperature in the bore of a superconducting magnet and registered photons with energies from 5 keV to 1000 keV. To enlarge the detection range, we also directly detected soft X-rays with energies between 0.2 keV and 20 keV with three large area APDs. The construction and operation of the detector is presented, as well as information on operation of APDs at cryogenic temperatures

Evaluation of the Efficacy of Vitrectomy for Persistent Diabetic Macular Edema and Associated Factors Predicting Outcome

PURPOSE: To evaluate the efficacy of vitrectomy for persistent diabetic macular edema after laser photocoagulation or intravitreal triamcinolone injections and to determine the demographic and ocular factors that influence functional and anatomical outcomes. METHODS: We retrospectively evaluated 55 eyes (51 patients) that had persistent diffuse macular edema after laser photocoagulation or intravitreal triamcinolone injections. We compared preoperative and postoperative best corrected visual acuity and macular thickness by Optical Coherence Tomography and investigated factors including patient's age, presence of vitreomacular traction, grade of diabetic retinopathy, and intraoperative internal limiting membrane removal that may influence the surgical results. RESULTS: The mean preoperative BCVA (log MAR) was 0.91+/-0.40 (0.8-1.2). The BCVA improved to 0.72+/-0.39 (0.3-1.2). The mean preoperative macular thickness was 440+/-130 (202-805) micrometer and the mean macular thickness decreased to 306+/-97 (136-580) micrometer postoperatively. The eyes showed statistically significant improvement in BCVA and central macular thickness (p<0.001). Preoperative better BCVA was associated with an improved postoperative visual acuity. (p=0.04). No other covariates were found to be statistically significant factors for prognosis of postoperative BCVA. CONCLUSIONS: In eyes with persistent diabetic macular edema after laser or IVTA injections, vitrectomy was effective for decreasing macular thickness and improvement of vision. The visual improvement after vitrectomy was associated with the preoperative better BCVA

Single-Dose Intravenous Toxicity Study of IRDye 800CW in Sprague-Dawley Rats

Objective: Fluorophore-labeled contrast imaging agents are moving toward clinical use for a number of applications. The near-infrared dye IRDye 800CW is frequently used in its N-hydroxysuccinamide (NHS) ester form for labeling these agents. Following conjugation or breakdown of a labeled ligand, excess NHS ester is converted to the carboxylate form. To prepare for clinical use as a near-infrared fluorophore, a toxicity study was conducted on IRDye 800CW carboxylate. Methods: Male and female Sprague–Dawley rats were given a single intravenous or intradermal administration of IRDye 800CW carboxylate; Indocyanine Green was used as a comparative control. Animals were injected with varying doses of the test and control articles and observed for up to 14 days. Clinical chemistry, hematological, and pharmacokinetic analyses were performed on subgroups of animals. Organs were analyzed for content of the test article. Tissues were analyzed microscopically for pathological changes. Results: Based on hematologic, clinical chemistry, and histopathologic evaluation, single administration of IRDye 800CW carboxylate intravenously at dose levels of 1, 5, and 20 mg/kg or 20 mg/kg intradermally produced no pathological evidence of toxicity. Conclusion: A dose of 20 mg/kg was identified as the no observed adverse effect level following IV or ID routes of administration of IRDye 800CW

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Mouflon sheep and rare plants on the island of Hawaiʻi, with an analysis of state ungulate management

M.S. University of Hawaii at Manoa 2013.Includes bibliographical references.Mouflon sheep (Ovis gmelini musimon), released in the 1960s for hunting, have been increasing in number and range, and represent a unique conservation threat on Hawaiʻi. Mouflon can jump fences built to exclude other ungulates, are habitat generalists, and are challenging to control. This study maps the distribution of mouflon islandwide and examines the risk to rare native plants and their habitat as mouflon range increases. Mouflon range now encompasses the entire central portion of the island. Because this has serious implications for rare plant recovery, the study also examines the policies and management practices under which this large range expansion of a state-regulated invasive ungulate occurred. The analysis reveals that Hawaiʻi's policy framework is not supportive of future ungulate control, or, by extension, rare plant recovery. This is important to consider in light of the recent discovery of axis deer (Axis axis) on the island

Molecular Phylogeny and Revision of Species Groups of Nearctic Bombardier Beetles (Carabidae: Brachininae: Brachinus)

Bombardier beetles of the genus Brachinus Weber are notorious for their explosive defensive chemistry; when threatened, they aim a 100°C cloud of benzoquinones directly at an enemy. Despite ongoing research on their defensive chemistry and ecology, the group lacks a robust molecular phylogeny. In this study, three loci from both the mitochondrial and nuclear genome (COI, CAD, 28S) were used to reconstruct the phylogeny of Nearctic Brachinus and to test hypothesized relationships based on a previous study based upon morphological characters (Erwin, 1970). All molecular phylogenetic analyses recovered all species groups proposed by Erwin as monophyletic except for the fumans species group. We find that Erwin’s fumans species group is polyphyletic. In its place, we erect the following five species groups: cinctipennis, fumans (revised), galactoderus, phaeocerus, and quadripennis. External morphological characters were traced on the molecular phylogeny to identify potential diagnostic characters. Apomorphic characters were identified for two new species groups, the fumans (revised) and phaeocerus groups. We also expand the cordicollis group to include B. medius and the americanus group

Residential Gardens in Urban Honolulu, Hawaiʻi: Neighborhood, Ethnicity and Ornamental Plants

PhD University of Hawaii at Manoa 1994Includes bibliographical references (leaves 189–198) and index.This study examines the relationship between people and plants in urban residential front yards on the island of Oʻahu, Hawaiʻi by comparing ornamental plant communities from three neighborhoods (study areas) with similar socioeconomic and cultural settings, and those of major ethnic groups (Japanese, Chinese and others -- mostly Caucasians) within these neighborhoods. A history of ornamental gardens tracing the Mediterranean-European and the Chinese-Japanese lineages is presented as background. Field sampling of the 150 randomly selected residential lots employed the sample stand method of vegetation ecology, and recorded the structure of the plant communities as presence/absence, height, cover, and function of each plant species in a yard. Statistical analyses (ANOVA and chi-square test) examined the relationships between vegetational characteristics and four socio-economic and cultural variables: (1) geographical location, (2) ethnic background, (3) the age of a house and (4) the size of a sample lot. Major findings include: (1) the structure of plant communities is quantitatively more similar than different both among neighborhoods and among ethnic groups; (2) the significant variations observed among neighborhoods are attributed to individual lot size, and to general landscape taste of residents of a neighborhood; (3) the similarity observed among ethnic groups suggests acculturation of cultural traditions, and the existence of a local (Hawaiian) style front yard utilizing popular tropical garden plants; (4) the front yards of some members of an ethnic group, especially the Japanese group, are distinguishable from the rest based on a few characteristics such as the presence of particular plant species (notably Japanese garden plants). This may be the residents' display of the symbols of group identity; (5) regarding the concept of transported landscape, not whole but parts of Japanese garden traditions, such as some plant species and a few ideas, have been transported to Hawai'i; and (6) the high species diversity implies individual residents' latitude of choice, and the uniform life form spectrum suggests the existence of the universal common image, protopaysage, among humans. Habitat theory suggests that this atavistic image hinkaku (dignity) leads us to portray the image in a pleasing form in a garden