Toward an integrated platform for characterizing laser-driven, isochorically heated plasmas with 1 µm spatial resolution.

Warm dense matter is a region of phase space that is of high interest to multiple scientific communities ranging from astrophysics to inertial confinement fusion. Further understanding of the conditions and properties of this complex state of matter necessitates experimental benchmarking of the current theoretical models. We discuss the development of an x-ray radiography platform designed to measure warm dense matter transport properties at large laser facilities such as the OMEGA Laser Facility. Our platform, Fresnel diffractive radiography, allows for high spatial resolution imaging of isochorically heated targets, resulting in notable diffractive effects at sharp density gradients that are influenced by transport properties such as thermal conductivity. We discuss initial results, highlighting the capabilities of the platform in measuring diffractive features with micrometer-level spatial resolution.

Habituation and individual variation in the endocrine stress response in the Trinidadian guppy (Poecilia reticulata).

The vertebrate stress response enables individuals to react to and cope with environmental challenges. A crucial aspect of the stress response is the elevation of circulating glucocorticoids. However, continued activation of the stress response under repeated exposure to stressors can be damaging to fitness. Under certain circumstances it may therefore be adaptive to habituate to repeated exposures to a particular stressor by reducing the magnitude of any associated release of glucocorticoids. Here, we investigate whether Trinidadian guppies (Poecilia reticulata) habituate to repeated exposure to a mild stressor, using a waterborne hormone sampling approach that has previously been shown to elicit a stress response in small fish. We also test for individual variation in the extent of habituation to this stressor. Concentrating on freely circulating cortisol, we found that the first exposure to the assay induced high cortisol release rates but that guppies tended to habituate quickly to subsequent exposures. There were consistent differences among individuals in their average cortisol release rate (after accounting for effects of variables such as body size) over repeated exposures. Our analyses did not find evidence of individual differences in habituation rate, although limitations in statistical power could account for this finding. We repeated the analysis for free 11-ketotestosterone, which can also respond to stressors, but found no obvious habituation pattern and no among-individual variation. We also present data on conjugated forms of both hormones, which were repeatable but did not show the expected time-lagged habituation effect. We discuss consistent individual differences around the general pattern of habituation in the flexible stress response, and highlight the potential for individual variation in habituation to facilitate selection against the deleterious effects of chronic stress.

Emersion behaviour underlies variation in gill morphology and aquatic respiratory function in the amphibious fish Kryptolebias marmoratus.

Fishes acclimated to hypoxic environments often increase gill surface area to improve O2 uptake. In some species, surface area is increased via reduction of an interlamellar cell mass (ILCM) that fills water channels between gill lamellae. Amphibious fishes, however, may not increase gill surface area in hypoxic water because these species can, instead, leave water and breathe air. To differentiate between these possibilities, we compared wild amphibious mangrove rivulus Kryptolebias marmoratus from two habitats that varied in O2 availability - a hypoxic freshwater pool versus nearly anoxic crab burrows. Fish captured from crab burrows had less gill surface area (as ILCMs were enlarged by ∼32%), increased rates of normoxic O2 consumption and increased critical O2 tension compared with fish from the freshwater pool. Thus, wild mangrove rivulus do not respond to near-anoxic water by decreasing metabolism or increasing O2 extraction. Instead, fish from the crab burrow habitat spent three times longer out of water, which probably caused the observed changes in gill morphology and respiratory phenotype. We also tested whether critical O2 tension is influenced by genetic heterozygosity, as K. marmoratus is one of only two hermaphroditic vertebrate species that can produce both self-fertilized (inbred) or out-crossed (more heterozygous) offspring. We found no evidence for inbreeding depression, suggesting that self-fertilization does not impair respiratory function. Overall, our results demonstrate that amphibious fishes that inhabit hypoxic aquatic habitats can use a fundamentally different strategy from that used by fully aquatic water-breathing fishes, relying on escape behaviour rather than metabolic depression or increased O2 extraction ability.

Changes in reproductive physiology of mangrove rivulus Kryptolebias marmoratus following exposure to environmentally relevant doses of ethinyl oestradiol.

Kryptolebias marmoratus exposed to 4 ng l(-1) of ethinyl oestradiol (EE2) for 30 days experienced significant changes in endogenous 17ß-oestradiol (E2) and 11-ketotestosterone (KT) and qualitative changes in gonad morphology. Both hermaphrodites and males showed a significant decrease in E2, whereas only males exhibited a significant decrease in KT. Exposure to EE2 resulted in a decrease in spermatid and spermatocyte density in males and an increase in the number of early stage oocytes in hermaphrodites.

The relationship between handling time and cortisol release rates changes as a function of brain parasite densities in California killifish Fundulus parvipinnis.

This study validated a technique for non-invasive hormone measurements in California killifish Fundulus parvipinnis, and looked for associations between cortisol (a stress hormone) and 11-ketotestosterone (KT, an androgen) release rates and the density or intensity of the trematode parasites Euhaplorchis californiensis (EUHA) and Renicola buchanani (RENB) in wild-caught, naturally infected F. parvipinnis. In experiment 1, F. parvipinnis were exposed to an acute stressor by lowering water levels to dorsal-fin height and repeatedly handling the fish over the course of an hour. Neither parasite was found to influence cortisol release rates in response to this acute stressor. In experiment 2, different F. parvipinnis were exposed on four consecutive days to the procedure for collecting water-borne hormone levels and release rates of 11-KT and cortisol were quantified. This design examined whether F. parvipinnis perceived the water-borne collection procedure to be a stressor, while also exploring how parasites influenced hormone release rates under conditions less stressful than those in experiment 1. No association was found between RENB and hormone release rates, or between EUHA and 11-KT release rates. The interaction between EUHA density and handling time, however, was an important predictor of cortisol release rates. The relationship between handling time and cortisol release rates was negative for F. parvipinnis harbouring low or intermediate density infections, and became positive for fish harbouring high densities of EUHA.

Iterative development and the scope for plasticity: contrasts among trait categories in an adaptive radiation.

Phenotypic plasticity can influence evolutionary change in a lineage, ranging from facilitation of population persistence in a novel environment to directing the patterns of evolutionary change. As the specific nature of plasticity can impact evolutionary consequences, it is essential to consider how plasticity is manifested if we are to understand the contribution of plasticity to phenotypic evolution. Most morphological traits are developmentally plastic, irreversible, and generally considered to be costly, at least when the resultant phenotype is mis-matched to the environment. At the other extreme, behavioral phenotypes are typically activational (modifiable on very short time scales), and not immediately costly as they are produced by constitutive neural networks. Although patterns of morphological and behavioral plasticity are often compared, patterns of plasticity of life history phenotypes are rarely considered. Here we review patterns of plasticity in these trait categories within and among populations, comprising the adaptive radiation of the threespine stickleback fish Gasterosteus aculeatus. We immediately found it necessary to consider the possibility of iterated development, the concept that behavioral and life history trajectories can be repeatedly reset on activational (usually behavior) or developmental (usually life history) time frames, offering fine tuning of the response to environmental context. Morphology in stickleback is primarily reset only in that developmental trajectories can be altered as environments change over the course of development. As anticipated, the boundaries between the trait categories are not clear and are likely to be linked by shared, underlying physiological and genetic systems.

Masculinized Sexual Ornaments in Female Lizards Correlate with Ornament-Enhancing Thermoregulatory Behavior.

The adaptive significance of colorful or exaggerated traits (i.e., ornaments) expressed in females is often unclear. Competing hypotheses suggest that expression of female ornaments arises from maladaptive (or neutral) genetic inheritance from males along with incomplete epigenetic regulation, or from positive selection for ornaments in females under social competition. Whether costly or advantageous, the visibility of such traits can sometimes be behaviorally modulated in order to maximize fitness. Female eastern fence lizards express blue badges that are variable in size and color saturation. These are rudimentary compared to those seen in males and carry important costs such as reduced mating opportunities. Body temperature is a well-established enhancer of badge color, and thus thermoregulation may be one way these animals modulate badge visibility. We quantified realized body temperatures of female lizards paired in laboratory trials and observed that females with larger badges attained higher body temperatures when freely allowed to thermoregulate, sometimes beyond physiological optima. In this association between phenotype and behavior, females with larger badges exhibited thermoregulatory patterns that increase their badges' visibility. This signal-enhancing behavior is difficult to reconcile with the widely held view that female ornaments are maladaptive, suggesting they may carry context-dependent social benefits.

É muitas vezes incerta a significância adaptativa de caracteres vívidos e coloridos em fêmeas. Hipóteses para esse fenômeno sugerem uma herança maladaptativa (ou neutra) de caracteres selecionados em machos aliada à regulação epigenética incompleta em fêmeas, ou ainda seleção positiva em fêmeas imposta por competição social. Vantajosos ou não, a visibilidade de ornamentos muitas vezes é modulada por vias comportamentais do portador de modo a balancear seus custos e benefícios. Fêmeas Sceloporus undulatus possuem um par de marcas verde-azuis na parte ventral do pescoço que são variáveis em área e saturação entre indivíduos. Esses ornamentos são rudimentares em relação aos vistos em machos, mas ainda assim estão associados a custos reprodutivos importantes. Nessa espécie, temperatura corporal aumenta a visibilidade desses ornamentos significativamente. Portanto, a termorregulação é um comportamento que fêmeas poderiam empregar para modular a visibilidade de ornamentos. Nós quantificamos temperaturas corporais obtidas por pares de lagartos fêmeas em testes comportamentais e observamos que fêmeas com os maiores ornamentos também obtiveram temperaturas corporais mais altas, às vezes além do ótimo fisiológico. Nesta associação entre fenótipo e comportamento, fêmeas com os maiores ornamentos exibiram padrões de termoregulação que aumentaram sua visibilidade. Este padrão é difícil de conciliar com a perspectiva de que ornamentos são maladaptativos em fêmeas, sugerindo benefícios que são dependentes do contexto social.

The Dynamic Compression Sector laser: A 100-J UV laser for dynamic compression research.

The Dynamic Compression Sector (DCS) laser is a 100-J ultraviolet Nd:glass system designed and built by the Laboratory for Laser Energetics for experimental research at the DCS located at the Advanced Photon Source (Argonne National Laboratory). Its purpose is to serve as a shock driver to study materials under extreme dynamic pressures. It was designed to deposit energy within a uniformly illuminated 500-µm spot on target, with additional optics provided to implement spot sizes of 250 and 1000 µm. Designed after larger-scale glass lasers such as OMEGA and the National Ignition Facility, the laser consists of a fiber front end with interferometer-based pulse shaping, a Nd:glass regenerative amplifier, a four-pass rod amplifier, and a 15-cm glass disk amplifier, through which six passes are made in a bowtie geometry. The output is frequency tripled from 1053 to 351 nm by using a pair of type-II phase-matched KDP crystals, with a third to increase conversion bandwidth. The super-Gaussian spot in the far field is achieved with a distributed phase plate and a 1-m aspherical focusing lens. Beam smoothing is achieved by smoothing by spectral dispersion and polarization smoothing, resulting in a root-mean-square variation in intensity on target of ±8.7%.

Claudin-1 overexpression in melanoma is regulated by PKC and contributes to melanoma cell motility.

Serial analysis of gene expression followed by pathway analysis implicated the tight junction protein claudin-1 (CLDN1) in melanoma progression. Tight junction proteins regulate the paracellular transport of molecules, but staining of a tissue microarray revealed that claudin-1 was overexpressed in melanoma, and aberrantly expressed in the cytoplasm of malignant cells, suggesting a role other than transport. Indeed, melanoma cells in culture demonstrate no tight junction function. It has been shown that protein kinase C (PKC) can affect expression of claudin-1 in rat choroid plexus cells, and we observed a correlation between levels of activated PKC and claudin expression in our melanoma cells. To determine if PKC could affect the expression of CLDN1 in human melanoma, cells lacking endogenous claudin-1 were treated with 200 nM phorbol myristic acid (PMA). PKC activation by PMA caused an increase in CLDN1 transcription in 30 min, and an increase in claudin-1 protein by 12 h. Inhibition of PKC signaling in cells with high claudin-1 expression resulted in decreased claudin-1 expression. CLDN1 appears to contribute to melanoma cell invasion, as transient transfection of melanoma cells with CLDN1 increased metalloproteinase 2 (MMP-2) secretion and activation, and subsequently, motility of melanoma cells as demonstrated by wound-healing assays. Conversely, knockdown of CLDN1 by siRNA resulted in the inhibition of motility, as well as decreases in MMP-2 secretion and activation. These data implicate claudin-1 in melanoma progression.

Developmental plasticity of the stress response in female but not in male guppies.

To survive, animals must respond appropriately to stress. Stress responses are costly, so early-life experiences with potential stressors could adaptively tailor adult stress responses to local conditions. However, how multiple stressors influence the development of the stress response remains unclear, as is the role of sex. Trinidadian guppies (Poecilia reticulata) are small fish with extensive life-history differences between the sexes and population variation in predation pressure and social density. We investigated how sex and early-life experience influence hormonal stress responses by manipulating conspecific density and perceived predation risk during development. In adults, we sampled cortisol twice to measure initial release and change over time in response to a recurring stressor. The sexes differed considerably in their physiological stress response. Males released more cortisol for their body mass than females and did not reduce cortisol release over time. By contrast, all females, except those reared at high density together with predation cues, reduced cortisol release over time. Cortisol responses of males were thus less dynamic in response to current circumstances and early-life experiences than females, consistent with life-history differences between the sexes. Our study underscores the importance of early-life experiences, interacting ecological factors and sex differences in the organization of the stress response.

Merging social hierarchies: Effects on dominance rank in male green swordtail fish (Xiphophorus helleri).

When the same set of individuals are placed in different social contexts, some groups members often experience a change in dominance status. We examined the context-dependence of social status using a group fusion protocol in male green swordtail fish (Xiphophorus helleri). Six individuals were matched for size and separated into two groups of three fish. Each triad established a stable hierarchy after which time the two subgroups were merged into one larger assemblage. The maintenance of within- and between-group rank relationships was examined. Relative rank was preserved within each subgroup across social contexts but we found no evidence that familiarity with dominant animals assists individuals of one subgroup in achieving higher rank (coat-tail effects). Dominant individuals from the pre-fusion groups were significantly likely to obtain high status in the merged group and vice versa for subordinate pre-fusion animals. These results demonstrate that social rank in swordtails is relatively impervious to changes in social context, but we address some deviations from this trend. Small differences in standard length were a significant predictor of the most dominant rank in the post-fusion hierarchy, with the largest animals tending to occupy the alpha position. We discuss our results in terms of the potential factors involved in within- and between-group rank maintenance, including individual recognition, winner and loser effects, or asymmetries in dominance-related characteristics.

Nonpeptidic inhibitors of human leukocyte elastase. 5. Design, synthesis, and X-ray crystallography of a series of orally active 5-aminopyrimidin-6-one-containing trifluoromethyl ketones.

The effects of changes in substitution in a series of 5-amino-2-pyrimidin-6-ones on both in vitro activity and oral activity in an acute hemorrhagic assay have been explored. These compounds contained either a trifluoromethyl ketone or a boronic acid moiety to bind covalently to the Ser-195 hydroxyl of human leukocyte elastase (HLE). Boronic acid-containing inhibitors were found to be more potent than the corresponding trifluoromethyl ketones in vitro but were less active upon oral administration. Compound 13b was found to offer the best combination of oral potency, duration of action, and enzyme selectivity and, as such, was selected for further biological testing. X-ray crystallography of a cocrystallized complex of compound 19m and porcine pancreatic elastase demonstrated that the inhibitor is bound to the enzyme in a manner similar to that found previously for a closely related series of pyridone-containing inhibitors of HLE.

Nonpeptidic inhibitors of human leukocyte elastase. 3. Design, synthesis, X-ray crystallographic analysis, and structure-activity relationships for a series of orally active 3-amino-6-phenylpyridin-2-one trifluoromethyl ketones.

A series of nonpeptidic inhibitors of human leukocyte elastase (HLE) is reported. These trifluoromethyl ketone-based inhibitors contain a 3-amino-6-phenylpyridone group as a central template. The effect of varying the N-3 substituent in these inhibitors on in vitro potency, physical properties, and oral activity in a hamster based, HLE-induced lung damage model is described. The variety of substituents at this position that have little effect on in vitro potency supports the idea that this region of the molecule does not interact strongly with the enzyme. One exception to this generality is 13k, which is substituted with a (4-acetamidophenyl)sulfonyl group. This compound has a K(i) of 0.7 nM and is, in vitro, the most potent inhibitor in the series. In contrast, variation of the N-3 substituent was found to have a dramatic effect on activity after oral administration. Several analogs, including the parent amine, 7, formamide, 2u, benzyl sulfamide, 13e, and benzyl sulfonamide, 13f, show significant activity when administered at an oral dose of 2.5 mg/kg. Support for the modeling-based design concepts was obtained through in vitro SAR results and X-ray crystallographic analysis of the complex between 13d and porcine pancreatic elastase (PPE), a closely related enzyme.

Orally active trifluoromethyl ketone inhibitors of human leukocyte elastase.

This paper describes the development a series of peptidyl trifluoromethyl ketone inhibitors of human leukocyte elastase which are found to have excellent pharmacological profiles. Methods have been developed that allow for the synthesis of these inhibitors in stereochemically pure form. Two of these compounds, 1k and 1l, have high levels of oral bioavailability in several species. Compound 1l has entered development as ZD8321 and is presently undergoing clinical evaluation. These compounds demonstrate that peptidyl trifluoromethyl ketone inhibitors can achieve high levels of oral activity and bioavailability, and therefore they may prove useful as therapeutic agents in the treatment of diseases in which elastase is implicated.

Ultrastructural cytochemical and autoradiographic demonstration of nonspecific esterase(s) in guinea pig basophils.

We used ultrastructural autoradiographic and cytochemical methods to localize esterase activities in unstimulated guinea pig basophils and in basophils undergoing degranulation or recovery from degranulation. We used tritium-labeled diisopropylfluorophosphate (DFP) as a probe for serine enzymes and localized this probe by ultrastructural autoradiography to cytoplasmic granules of immature or mature unstimulated basophils, as well as to granules released by degranulating basophils. Ultrastructural cytochemistry using alpha naphthyl acetate (ANA) as substrate localized nonspecific esterase activity to extruded granules, either within the interiors of degranulation sacs or within granules completely separated from degranulating basophils. Extruded granules retained their esterase activity for as long as 24 hr after antigen-induced degranulation. The plasma membranes of unstimulated or degranulating basophils, as well as of basophils recovering from degranulation, displayed prominent cell surface ANA esterase ectoenzyme activity. Lipid bodies, organelles present in the cytoplasm of both control and recovering basophils, were also alpha naphthyl acetate esterase (ANAE)-positive. Thus, cytochemical and autoradiographic techniques localized esterase and/or [3H]-DFP-binding activities to cytoplasmic granules, lipid bodies, and cell surface of basophils, and these enzyme activities persisted during both degranulation and recovery from degranulation.

Nonspecific esterase activity expressed in Weibel-Palade bodies of cloned guinea pig aortic endothelial cells.

We studied the localization of nonspecific esterase activities in cloned guinea pig aortic endothelial cells using ultrastructural cytochemistry. Weibel-Palade bodies (WPB), which are known to contain von Willebrand protein, were positive for esterase, defining a heretofore unrecognized activity of these organelles. Esterase activity was also found localized to the external surface of the plasma membrane, to cytoplasmic lipid bodies, and to the outer (cytoplasm-facing) surface of certain membrane-bound cytoplasmic vacuoles. Localization of esterase activity to these four discrete sites probably reflects the presence of a number of endothelial cell enzymes capable of hydrolyzing alpha-naphthyl acetate or butyrate. The physiological substrate and biological function of these enzyme activities are not presently understood.

Pulsed electrochemical detection of penicillins using three and four step waveforms.

Aided by the construction of a custom potentiostat, a series of different PAD waveforms were compared to find the optimum detector for penicillin oxidation. The waveforms included standard 3-step direct and indirect PAD in addition to reverse-PAD and 4-step PAD. Two new waveforms, the indirect reverse-PAD and the 4-step indirect PAD were examined in the study. Under the solvent conditions of the study (0.01M acetate buffer, pH 4.6) the indirect waveforms yielded the best detectability for penicillin G while the reverse-PAD waveforms yielded the worst performance. The 4-step PAD methods did not improve detectability when compared to the 3-step types, but they did provide output peak profiles with better shapes and less tailing. Although indirect waveforms gave better detectability than direct detection in the 0.01M acetate buffer solution, the limits of detection for each were found to be differing functions of ionic strength. At higher acetate concentrations, direct PAD was more favorable than indirect detection.

The application of flow programming with pulsed amperometric detection for liquid chromatography.

A mixture of seven penicillins was separated on a C-8 column and detected using pulsed amperometric detection (PAD). Due to the polarity range of the penicillin mixture, a gradient program was necessary to produce a reasonable separation, causing some baseline shifting. Application of a flow program, where the solvent flow rate is varied within the separation, was also examined, and found to cause only a small shift in baseline response for PAD. Further examination of a variety of different flow programs was undertaken to characterize the baseline and analyte response under these conditions. Notable was that the shift in baseline from the flow program could be altered to give a shift toward either increased or decreased current, depending on the waveform and solvent combination in use. By manipulating these two parameters, one can customize the PAD response to a flow program, which may allow flow programs to be designed that only produce a minimal impact on the detector response.

A consideration of electrode polishing prior to application of pulsed amperometric detection.

An examination was made of the effect of electrode polishing on the direct pulsed amperometric detection (PAD) and indirect PAD response to penicillin G. The polishing procedure produced a temporary loss of sensitivity for both types of PAD, which over time relaxed back to higher levels. A temporary increase in the electrode kinetics can be observed as well, particularly for a PAD waveform in the crossover region between direct and indirect PAD. In extreme cases, the penicillin G response can undergo a complete polarity reversal. By observing post-polish equilibration times, it was recommended that the direct and indirect PAD user observe 3 and 5 h delay times, respectively, to insure stable electrode response following an electrode polish.

Clinical and histologic changes determine optimal treatment regimens for microdermabrasion.

OBJECTIVE: To analyze the onset and extent of the dermatological changes associated with microdermabrasion. METHODS: Eleven volunteers, aged 31-62 years old, underwent a series of six aluminum oxide microdermabrasion facial treatments spaced over 7 to 10-day intervals. White light photography and digital ultraviolet fluorescent photography and skin biopsies were obtained prior to the study, after three treatments, and after six treatments. A 90-day no-treatment period ensured, after which biopsies and photographs were taken. RESULTS: Clinical improvements in dyschromia, actinic changes and fine rhytides were observed after six treatments. Compared with the controls, the treated areas demonstrated the following histological changes: epidermal thickening with basal cell hyperplasia and mitotic activity; flattening and widening of the rete pegs; papillary dermal thickening with deposition of collagen and elastic fibers; and perivascular inflammation in the dermis. After the no-treatment period some of the clinical and histologic changes persisted although they were less than those present immediately after the last treatment. Serial ultraviolet photography following microdermabrasion treatments revealed changes in the skin's pigmentation pattern that correlated clinically with improvements in dyschromia. CONCLUSION: Clinical and histological changes are most likely secondary to a mechanism resembling a reparative process. The persistent changes after a period of no-treatment suggests that some of the changes could be permanent. Clinicians can use this data to better determine the optimal interval frequency and treatment intervals with microdermabrasion.