Biochemical composition of ovary, embryo, and hepatopancreas in the grapsoid crabs Armases cinereum and Sesarma nr. reticulatum (Crustacea, Decapoda).

Biochemical composition of ovary, embryo, and hepatopancreas tissues in wild populations of Armases cinereum and Sesarma nr. reticulatum were monitored during the reproductive season. Total lipid, carbon, nitrogen, C:N ratio, and water concentration of the ovary, hepatopancreas and embryos were quantified over the course of ovarian maturation. Ovary nitrogen concentration decreased as ovaries matured. Ovary lipid and carbon concentration differed significantly over the course of ovarian maturation for both species, but there was no relationship between the concentration or total content of hepatopancreas lipid and the stage of ovarian development in females. Neither species showed a relationship between measures of hepatopancreas lipid and the gonadosomatic index. There was also no simultaneously measurable net decrease in mass of the females' hepatopancreas. Lipid demands of ovarian maturation thus appear to be met in large part by increased dietary intake rather than by substantial draw down of pre-existing lipid stores from the hepatopancreas. While these temperate grapsoid crabs live with putatively fluctuating quality and quantity of food resources, no evidence could be found to demonstrate depletion of lipid concentrations in the hepatopancreas concomitant with ovarian maturation.

Genetic, ecological, and behavioural divergence between two sibling snapping shrimp species (Crustacea: Decapoda: Alpheus).

Examination of genetic and ecological relationships within sibling species complexes can provide insights into species diversity and speciation processes. Alpheus angulatus and A. armillatus, two snapping shrimp species with overlapping ranges in the north-western Atlantic, are similar in morphology, exploit similar ecological niches and appear to represent recently diverged sibling species. We examined phylogenetic and ecological relationships between these two species with: (i) sequence data from two mitochondrial genes (16S rRNA and COI); (ii) data on potential differences in microhabitat distribution for A. armillatus and A. angulatus; and (iii) data from laboratory experiments on the level of reproductive isolation between the two species. DNA sequence data suggest A. armillatus and A. angulatus are sister species that diverged subsequent to the close of the Isthmus of Panama, and that haplotype diversity is lower in A. armillatus than in A. angulatus. Both species are distantly related to A. heterochaelis and A. estuariensis, two species with which A. angulatus shares some similarities in coloration. Ecological data on the distribution of A. angulatus and A. armillatus from two locations revealed differences in distribution of the two species between habitat patches, with each patch dominated by one or the other species. However, there was no apparent difference in distribution of the two species within habitat patches with respect to microhabitat location. Ecological data also revealed that heterospecific individuals often occur in close proximity (i.e. within metres or centimetres) where sympatric. Behavioural data indicated that these species are reproductively isolated, which is consistent with speciation in transient allopatry followed by post-divergence secondary contact. Our data further resolve taxonomic confusion between the sibling species, A. armillatus and A. angulatus, and suggest that sympatry in areas of range overlap and exploitation of similar ecological niches by these two recently diverged species have selected for high levels of behavioural incompatibility.

Highly luminescent Cu(I)-phenanthroline complexes in rigid matrix and temperature dependence of the photophysical properties.

We synthesized new [Cu(NN)(2)](+)-type complexes where NN = 2-5 and denotes a 2,9-disubstituted-1,10-phenanthroline ligand (related complexes of 1 and 6 ligands are used for reference purposes). For 2, 3, and 4 the ligand substituents are long alkyl-type fragments, whereas in 5 a phenyl ring is directly attached to the chelating unit. At 298 K the four complexes display relatively intense metal-to-ligand-charge-transfer (MLCT) emission bands with maxima around 720 nm, Phi(em) approximately 1 x 10(-)(3) and tau > 100 ns in deaerated CH(2)Cl(2). The emission behavior at 77 K in a CH(2)Cl(2)/MeOH matrix is quite different for complexes of alkyl- (2-4) versus phenyl-substituted (5) ligands. The former exhibit very intense emission bands centered around 642 nm and hypsochromically shifted with respect to 298 K, whereas the luminescence band of [Cu(5)(2)](+) is faint and shifted toward the infrared side. These results prompted us to study in detail the temperature dependence of luminescence properties of [Cu(2)(2)](+) and [Cu(5)(2)](+) in the 300-96 K range. For both complexes the excited state lifetimes increase monotonically by decreasing temperatures, and the trend is well described by an Arrhenius-type treatment involving two equilibrated MLCT excited levels. The emission bands show a similar behavior for the two compounds (intensity decrease and red-shift) only in the 300-120 K range, when the solvent is fluid. In the frozen regime (T

A liquid crystalline supramolecular complex of C60 with a cyclotriveratrylene derivative

Cyclotriveratrylene (CTV) derivatives substituted with 9 (1) or 18 (2) long alkyl chains have been prepared. Whereas no liquid crystalline behavior has been observed for 1, the CTV derivative 2 has mesomorphic properties. Indeed, at room temperature compound 2 exhibits a nematic phase characterized by cybotactic groups with a local lamello-columnar order. Both CTV derivatives 1 and 2 are able to form supramolecular complexes with C60 in the solid state. In both cases, the 2:1 host-guest species have been obtained as brown compounds. No liquid crystalline behavior was observed for the supramolecular complex [C60 is included in (1)2]. In contrast, observation of the brown product obtained from C60 and the CTV derivative 2 directly after preparation by polarized optical microscopy revealed a fluid birefringent phase at room temperature. When the sample is heated above 70 degrees C, the birefringence of the texture under the microscope disappears and the X-ray diffraction pattern is transformed into a pattern characteristic of a cubic phase. For the first time in thermotropic liquid crystals, the space group of this cubic phase can be assigned as I4(1)32.

Molecular phylogeny, taxonomy, and evolution of nonmarine lineages within the American grapsoid crabs (Crustacea: brachyura).

Grapsoid crabs are best known from the marine intertidal and supratidal. However, some species also inhabit shallow subtidal and freshwater habitats. In the tropics and subtropics, their distribution even includes mountain streams and tree tops. At present, the Grapsoidea consists of the families Grapsidae, Gecarcinidae, and Mictyridae, the first being subdivided into four subfamilies (Grapsinae, Plagusiinae, Sesarminae, and Varuninae). To help resolve phylogenetic relationships among these highly adaptive crabs, portions of the mitochondrial genome corresponding to the 16S rRNA gene were sequenced for all grapsoid genera occurring in America. The resulting phylogeny confirms most of the present grapsid subfamilies but suggests reclassification of some of the genera and recognition of new taxonomic units. The two American gecarcinid genera might not represent a sister group to the Grapsidae but rather appear to have evolved within the latter. Colonization of inland habitats evolved in several lineages of the grapsoids, resulting in various forms of nonmarine life and different degrees of independence from the sea.

Investigations of Thin Films with Amphiphilic Dendrimers Bearing Peripheral Fullerene Subunits.

In spite of a molecular mass of 7704.6 g mol(-1), third-generation compound G3 (shown schematically; Z=C(8)H(17)) is able to form stable Langmuir films. In a systematic study, the amphiphilic properties of the corresponding dendrimers of first (G1) and second generation (G2), with one and two peripheral fullerene units, respectively, were investigated and a model could be proposed for the multilayer films obtained from G1.

A Copper(I) Bis-phenanthroline Complex Buried in Fullerene-Functionalized Dendritic Black Boxes.

Virtual inaccessibility to external contact was revealed by electrochemical investigations for a bis(1,10-phenanthroline)copper(I) core embedded in dendrimers with up to 16 peripheral fullerene units (shown schematically). With increasing numbers of fullerene units, less and less light is available to the core, and the small quantity of light energy that reaches the central Cu(I) complex is returned to the external fullerenes by energy transfer-the central core is buried in a dendritic black box.

CO(2) laser resurfacing over facial flaps.

The authors demonstrate the safety and efficacy of combining CO(2) laser resurfacing techniques with other facial rejuvenation surgical procedures. During the past 22 months, we have developed a technique in which variable energy levels are matched to area skin thickness and adnexal structures, allowing safer CO(2) laser applications. We began with limited skin flap laser resurfacing and have expanded this technique to resurface entire faces to achieve both wrinkle removal and skin shrinkage. Experienced plastic surgeons following specific guidelines can safely combine full facial laser resurfacing techniques with surgical facial rejuvenation.

CO2 laser skin resurfacing in oculoplastic surgery.

Although CO2 lasers have been used in medicine for almost 30 years, recent developments have changed the way they are being used. Several laser technologies have altered the CO2 laser delivery system, making it useful for the treatment of wrinkles, photoaged skin, and acne scarring. Histopathologically, the resurfacing CO2 lasers produce morphologic alterations similar to medium-depth chemical peels. Many of the same principles applied to chemical peels and dermabrasion are useful in the evaluation and treatment of patients undergoing laser resurfacing. The results of laser therapy appear to be more predictable than those from dermabrasion and chemical peeling and produce fewer sequelae. Laser resurfacing can be used alone or as an adjunct to other cosmetic surgical procedures.

Reproductive Ecology of an Intertidal Brachyuran Crab, Sesarma sp. (nr. reticulatum), from the Gulf of Mexico.

The natural history and reproductive ecology of a presently undescribed marsh crab endemic to the Gulf of Mexico were studied in both the laboratory and the field. Weekly sampling of populations in coastal Louisiana allowed us to determine the periodicity of molting and ovarian development, as well as the seasonal variation in egg laying and size of individual egg masses. Timing of molt, egg laying, and egg hatching were monitored in individual females under simulated tidal cycles in laboratory mesocosms. Peak periods of reproductive activity in Louisiana coincide with favorable temperatures and elevated primary productivity in coastal waters. Size cohort and fecundity differ between these periods. Egg-laying, larval release, and molting observed in individual females in the laboratory and extrapolated dates of egg-laying and larval release for those in field samples exhibit a semilunar influence throughout the season. Female receptivity to mating is tied to egg-laying. Rate of embryonic development was associated with decreases and increases in egg size. Behavior related to larval release is described. Adaptive significance in relation to the intertidal marsh habitat is discussed.

Ontogenetic Change in Digestive Enzyme Activity of Larval and Postlarval White Shrimp Penaeus setiferus (Crustacea, Decapoda, Penaeidae).

Whole specimens of developmental stages of Penaeus setiferus (Linnaeus, 1767) were homogenized and assayed for activities of digestive enzymes. In all developmental stages, activities were present for trypsin, carboxypeptidase A and B, amylase, and non-specific esterase; none for pepsin or lipase were detected. Activities assayed with substrates for chymotrypsin and aminopeptidase are not apparently due to the presence of these enzymes in the gut. Peak activities for all enzymes occurred during late zoeal or early mysis larval stages; low activities occurred at metamorphosis. During postlarval development, amylase activity increased steadily (by a tenfold increase over five weeks), whereas most other enzyme activities were relatively constant until the fifth week of postlarval development. Although it alters enzyme activity, diet does not appear to be the primary effector of ontogenetic change in digestive enzyme activity. Instead, ontogenetic change in digestive enzyme activity may reflect either a developmentally cued change in enzyme synthesis, or a secondary effect of change in the function and relative size of the midgut during its differentiation.

Ontogenetic Changes in Enzyme Distribution and Midgut Function in Developmental Stages of Penaeus setiferus (Crustacea, Decapoda, Penaeidae).

Ultrastructure and histochemical distribution of enzymes were examined in the midgut of larval and postlarval stages of Penaeus setiferus. Acid phosphatase and esterase activities were present in all gut tissues at all stages. Protease activity was present in the anterior and lateral midgut caeca, as well as in the anterior portion of the midgut trunk (MGT) of larvae and early postlarvae (PL1-PL4). Amylase activity could not be detected histochemically in larvae or early postlarvae, even though it was detected in assays of whole-animal homogenates. In later postlarvae, both protease and amylase activities were present in the hepatopancreas and anterior MGT, but were absent from the anterior midgut diverticulum. In larvae, alkaline phosphatase activity is present throughout the midgut, suggesting that absorption is widespread. In juveniles, activity is restricted to the hepatopancreas and regions of the MGT within the cephalothorax. The abdominal MGT (or "intestine") is no longer absorptive by the time the hepatopancreas has attained its adult form. Although epithelial cells of the MGT synthesize protein and produce electron-dense secretory vesicles, they are substantially different in ultrastructure from those cells in the hepatopancreas responsible for digestive enzyme synthesis and secretion. Epithelial cells of the larval anterior and lateral midgut caeca are structurally and functionally similar to cells of the postlarval hepatopancreas. However, the lateral midgut caeca retain these features as they transform into the hepatopancreas, while the anterior midgut caeca lose these functions as they degenerate into the anterior diverticulum and change in ultrastructure during early postlarval development. The anterior and posterior midgut diverticula of postlarvae are similar ultrastructurally even though they differ in ontogenetic history.

Primary orbital neuroblastoma.

A 35-year-old man had a primary neuroblastoma of the left orbit. Histopathologically, the tumor was composed of uniform small round cells containing argyrophilic granules arranged in nests and cords with pseudorosettes, Homer-Wright rosettes, and a fine fibrillary background matrix. Immunohistochemical staining for chromogranin was positive. Electron microscopy showed small (108- to 173-nm) dense core granules. Eight years after surgery and radiation therapy the patient was free of local recurrence and metastases. To our knowledge, primary orbital neuroblastoma has been reported only once previously. Neuroblastoma, which occurs most frequently in children and has an incidence in the United States of 500 cases annually, is a distinctly unusual tumor in adults.

Analysis of fatty acid methyl esters with high accuracy and reliability. VI. Rapid analysis by split injection capillary gas-liquid chromatography.

Of the several facets of technique that must be addressed to allow the generation of highly accurate results by gas chromatographic analysis of fatty acid methyl esters, that of split injection to capillary columns has long been a major problem. A practical solution of this problem is now proposed. Three factors were found to be of major importance in achieving highly accurate results viz. avoidance of needle discrimination when injecting, very rapid vaporisation of the sample and complete homogenisation of the sample with the carrier gas stream. High speed of injection was found to be a highly effective means of avoiding needle discrimination. Rapid vaporisation of the sample was achieved by the use of relatively dilute solutions of analyte in the solvent, the smallest sample size commensurate with obtaining a chromatogram that could be accurately quantitated and, particularly, by the use of injector temperatures considerably higher than those generally adopted. Good mixing of the vaporized sample with the carrier gas was achieved with a number of injector insert designs, but, with improvement of design, it was found possible to achieve linear splitting over a wide range of operating conditions. The most controversial recommendation is to use very high injection temperatures, but it has been shown that the commonly held view that this may cause pyrolysis of fatty acid methyl esters is not true, even when the esters are highly unsaturated.

Effects of repetitive bursts of vagal activity on atrioventricular junctional rate in dogs.

A stable atrioventricular (AV) junctional rhythm was produced in open-chest dogs by injecting pentobarbital into the sinus node artery. When the cervical vagus nerves were stimulated repetitively, the junctional pacemaker cells tended to become synchronized with the vagal activity. During such synchronization, the junctional rate varied directly rather than inversely with the frequency of vagal stimulation. The magnitude of the chronotropic response depended on the timing of the vagal stimuli within the cardiac cycle. In 9 dogs, when the mean heart periods were plotted as a function of the R-st intervals (i.e., the time from the beginning of ventricular depolarization to the beginning of the stimulus burst), the mean heart periods varied from a maximum of 1,815 ms to a minimum of 1,160 ms, depending on the R-st interval. A small change in the R-st interval was capable of evoking a relatively large change in cycle length. Therefore, the impulses from various efferent vagal fibers to the AV junction must arrive almost synchronously, the released acetylcholine must be removed rapidly, and the sensitivity of the pacemaker cells to acetylcholine must change rapidly at some critical time during the cardiac cycle.

Autonomic control of pacemaker activity in the atrioventricular junction of the dog.

A stable atrioventricular (AV) junctional rhythm was induced in open-chest, anesthetized dogs by injecting pentobarbital into the sinus node artery. A factorial experimental design was used to quantify the changes in AV junctional rate as a function of the frequency of cardiac sympathetic and parasympathetic stimulation. The AV junctional pacemaker cells were more responsive to autonomic neural stimulation, but the vagal-sympathetic interactions were less pronounced than had previously been observed for the SA nodal pacemaker cells. In a group of seven animals, sympathetic stimulation at a frequency of 1.4 Hz increased the AV junctional rate by 102% from a control rate of 54 beats/min. In the same animals, vagal stimulation at a frequency of 8.4 Hz reduced the AV junctional rate by 56%. In three other animals, the AV junction was even more responsive; equivalent chronotropic effects were achieved with stimulation frequencies that were only about one-third of those cited above. There was a moderate, but significant, autonomic interaction: in the group of seven animals, the positive chronotropic effect of sympathetic stimulation at 1.4 Hz was 72% greater at the low level (0 Hz) than at the high level (8.4 Hz) of vagal activity.

Osmotic and ionic regulation in several Western atlantic callianassidae (crustacea, decapoda, thalassinidea).

Osmotic and ionic regulatory capacities of callianassid mud shrimps, Callianassa jamaicense, C. major, and C. islagrande, are correlated to their distributions on the Louisiana coast. Callianassa jamaicense burrows in muddy estuaries where salinity may commonly fall to < 5 per thousand, but C. major and C. islagrande usually burrow in sandy beaches bathed by higher salinities. Lower lethal limits of salinity are < 2 per thousand for C. jamaicense, 7-8 per thousand for C. major and probably just below 15 per thousand for adult C. islagrande. After exposure to low salinity C. jamaicense exhibits better volume control than the other two species. Blood osmotic, sodium, and chloride concentrations in C. jamaicense are regulated near stable levels at acclimation salinities beneath approximately 20 per thousand but those of C. major and C. islagrande are not. Blood magnesium is slightly hyper-regulated by C. jamaicense at most acclimation salinities < 25 per thousand and more markedly hyper-regulated at salinities < 10 per thousand; it is also slightly hyper-regulated by C. major at acclimation salinities < 30 per thousand. After direct transfer of C. jamaicense from 20 per thousand salinity to 3 per thousand salinity, blood osmotic, sodium, and chloride concentrations fall slightly but approach stable concentrations within 12 hours; blood magnesium concentration falls less rapidly. When C. jamaicense is transferred from 20 to 37 per thousand, blood osmotic, sodium, and chloride concentrations increase markedly during the first day and continue to slowly increase through day 9; blood magnesium increases to a near stable level by day 4. Differences in osmoregulatory capacities, along with substrate preferences, appear to limit distributions of Callianassidae on the Louisiana coast. With one exception, previous studies suggest that osmoregulatory ability does not occur in this group. The present report of osmoregulatory ability in C. jamaicense documents a second exception.