High-resolution Digital Imaging System Research Articles

The impact of genetic restoration on cranial morphology of Florida panthers (Puma concolor coryi)

The breeding population of the endangered Florida panther (Puma concolor coryi) is confined to the southern portion of the Florida peninsula. During the 20th century, a combination of isolation and small population size resulted in increased inbreeding. This ultimately led to a genetic restoration program in 1995 to alleviate correlates of inbreeding depression and avert extinction of the Florida panther. Genetic restoration involved the release of 8 female Texas pumas into the wild Florida population, a management initiative that has significantly improved the outlook for recovery. It is unknown whether genetic restoration changed the distinctive cranial morphology of the Florida panther; and whether some metrics that were historically used to differentiate Florida panthers from other subspecies of P. concolor are still valid. We used a high-resolution digital imaging system to compare cranial morphology from several groupings of Florida panthers that were defined by genetic restoration to elucidate any morphological changes this event may have had on cranial profile. Our results indicated that cranial measurements of Florida panthers were not significantly altered by genetic restoration.

Evolution of Fe based intermetallic phases in Al–Si hypoeutectic casting alloys: Influence of the Si and Fe concentrations, and solidification rate

Al–Si–Fe hypoeutectic cast alloy system is very complex and reported to produce numerous Fe based intermetallic phases in conjunction with Al and Si. This publication will address the anomalies of phase evolution in the Al–Si–Fe hypoeutectic casting alloy system; the anomaly lies in the peculiarities in the evolution and nature of the intermetallic phases when compared to the thermodynamic phase diagram predictions and past publications of the same. The influence of the following parameters, in various combinations, on the evolution and nature of the intermetallic phases were analyzed and reported: concentration of Si between 2 and 12.6 wt%, Fe between 0.05 and 0.5 wt% and solidification rates of 0.1, 1, 5 and 50 K s−1. Two intermetallic phases are observed to evolve in these alloys under these solidification conditions: the τ5-Al8SiFe2 and τ6-Al9Fe2Si2. The τ5-Al8SiFe2 phase evolves at all levels of the parameters during solidification and subsequently transforms into the τ6-Al9Fe2Si2 through a peritectic reaction when promoted by certain combinations of solidification parameters such as higher Fe level, lower Si level and slower solidification rates. Further, it is also hypothesized from experimental evidences that the θ-Al13Fe4 binary phase precludes the evolution of the τ5 during solidification and subsequently transforms into the τ6 phase during solidification. These observations are anomalous to the publications as prior art and simulation predictions of thermodynamic phase diagrams of these alloys, wherein, only one intermetallic phases in the τ6-Al9Fe2Si2 is predicted to evolve and be retained as the terminal phase at the end of solidification. Several analysis methods such as light optical microscope, scanning electron microscope equipped with a dual beam focused ion beam milling machine and energy dispersive X-ray diffraction system, transmission electron microscope equipped with high resolution digital imaging system, energy dispersive X-ray diffraction system, and high energy synchrotron beam source for nano-diffraction coupled with X-ray fluorescence imaging system was used in this study.

Deployment of an imaging system to investigate fine-scale spatial distribution of early life stages of the ctenophore Mnemiopsis leidyi in Chesapeake Bay

A high-resolution digital imaging system, the zooplankton visualization and imaging system (ZOOVIS) was deployed in the mid-region of Chesapeake Bay to investigate the fine-scale distribution of small individuals of the lobate ctenophore Mnemiopsis leidyi. Counts of individuals, mostly ,5 mm, were enumerated from each frame of ZOOVIS and merged with data from a conductivity-temperaturedepth to provide corresponding values of depth, temperature and salinity. Mnemiopsis leidyi rarely occurred below the pycnocline depth but commonly occurred in the upper water column. Where the water column was strongly stratified, M. leidyi tended to be more common near the pycnocline, but it was more abundant near the bottom at locations where the water column was well mixed. Horizontally, M. leidyi was more abundant on the shoulders of the middle Bay than in the deeper main channel. In this survey, M. leidyi occurred more frequently in relatively warm and low salinity water. Furthermore, small M. leidyi were patchily distributed and the patch size was ,700 m in horizontal extent. A zero-inflated, general additive model successfully simulated the spatial distribution of M. leidyi, with temperature and salinity as predictors. The ZOOVIS system proved to be a valuable tool to study fine-scale distributions of small and delicate gelatinous zooplankton, even in the relatively turbid conditions that prevailed in this estuarine system.

Identification of dyed jadeite using visible reflection spectra

Burma jadeites are often dyed to improve their colour. Most dyed jadeites are identifi ed using a microscope or a high resolution digital imaging system. However, when dye-related microscopic features are not clear, their visible refl ection spectra can be used for identifying dyed jadeite rapidly and accurately. This visible spectral method can be used to identify both dyed-only jadeite (C type) and the dyed and impregnated jadeites (B+C type), which may otherwise be diffi cult to distinguish.

Focus on spectroscopy

Focus on spectroscopy

Head area measurements of dead, live, X- and Y-bearing bovine spermatozoa

The head area of bull spermatozoa was measured after viability and acrosome staining using trypan blue and Giemsa stains, followed by X- and Y-chromosome-specific fluorescence in situ hybridisation (FISH). The former staining made possible the categorisation of cells according to morphology and membrane integrity, whereas the latter allowed distinction of spermatozoa bearing X- and Y-chromosomes. Individual spermatozoa could be followed during the consecutive steps of staining, measurement and FISH. Using a high-resolution digital imaging system and measurement software, the head area of more than 3000 cells of five bulls was determined precisely. In all bulls, morphologically normal, viable cells with intact acrosomes were significantly smaller than dead cells with damaged acrosomes. No significant difference in the head area between X- and Y-chromosome-bearing viable, acrosome-intact spermatozoa was found in individual bulls. However, significant between-bull differences were detected in all cell categories.

The Ca2+ concentration of the endoplasmic reticulum is a key determinant of ceramide-induced apoptosis: significance for the molecular mechanism of Bcl-2 action.

The mechanism of action of the anti-apoptotic oncogene Bcl-2 is still largely obscure. We have recently shown that the overexpression of Bcl-2 in HeLa cells reduces the Ca2+ concentration in the endoplasmic reticulum ([Ca2+]er) by increasing the passive Ca2+ leak from the organelle. To investigate whether this Ca2+ depletion is part of the mechanism of action of Bcl-2, we mimicked the Bcl-2 effect on [Ca2+]er by different pharmacological and molecular approaches. All conditions that lowered [Ca2+]er protected HeLa cells from ceramide, a Bcl-2-sensitive apoptotic stimulus, while treatments that increased [Ca2+]er had the opposite effect. Surprisingly, ceramide itself caused the release of Ca2+ from the endoplasmic reticulum and thus [Ca2+] increased both in the cytosol and in the mitochondrial matrix, paralleled by marked alterations in mitochondria morphology. The reduction of [Ca2+]er levels, as well as the buffering of cytoplasmic [Ca2+] changes, prevented mitochondrial damage and protected cells from apoptosis. It is therefore concluded that the Bcl-2-dependent reduction of [Ca2+]er is an important component of the anti-apoptotic program controlled by this oncogene.

The KidSat project flight system

This paper was written to discuss the technical aspects of granting students in classrooms the ability to explore and study Earth sciences from a unique view of our planet. A high-resolution digital imaging system mounted in the space shuttle cabin window made it possible, in part, to provide real-time student interaction with the space program. This access provided an individual ownership of research and interest in our environment and Earth sciences. The other project technical elements, also key to the program success and real-time student interaction, were the University of California, San Diego (UCSD) web-based mission operations system and the Jet Propulsion Laboratory (JPL) ground data system.