A molecular dynamics study on the thermal rectification effect at the solid–liquid interfaces between the face-centred cubic (FCC) of gold (Au) with the surfaces of (100), (110) and (111) crystal planes facing the liquid methane (CH4)

A molecular dynamics study on the solid–liquid (S-L) interfaces for solid wall of gold having the face-centred cubic of (100), (110) and (111) crystal planes contacting liquid methane was examined using non-equilibrium molecular dynamics simulations. An investigation on the thermal rectification effect was performed by measuring the thermal boundary conductance (TBC) at the S-L interface. Thermal rectification can be defined as the differences in the TBC at the interface between the two opposite heat flow directions; one is from the liquid to solid and vice versa. The thermal rectifications are up to 13% for (110) crystal plane, followed by 6% and 0.3% for (111) and (100) crystal planes, respectively. It was found that the TBC at the S-L interface was influenced by the magnitude of the adsorption of liquid molecules at the vicinity of the interface. The results show that due to the different temperature distribution, different magnitude of the adsorption of liquid molecules is generated for the two opposite heat flow directions. On the surface of the solid walls for (110) crystal plane, where lattice-scale corrugation exists, it was found that there exists difference in distance between the surface layers of the solid and liquid across the interface between the cases of the two opposite heat flow directions, which affects the TBC at the interface. The present results suggest that the factors that influence the thermal rectification at the S-L interface are the magnitude of the adsorption of liquid molecules and the surface structure of the solid walls that differ significantly among the three types of crystal planes.     

Feeding habits of the gilthead seabream (Sparus aurata) from the Ria Formosa (southern Portugal) as compared to the black seabream (Spondyliosoma cantharus) and the annular seabream (Diplodus annularis)

The feeding habits of Sparus aurata L., Diplodus annularis L. and Spondyliosoma cantharus L. in the Ria Formosa (southern Portugal) lagoon system were studied using three simple methods (frequency of occurrence, numeric percentage and percentage weight) and a composite index [index of relative importance (IRI)]. The Ivlev index was used to evaluate diet selectivity, while the Schoener overlap index was used to compare diets, and diet diversity was characterized by the Simpson index. The diets of the three species consist of a wide variety of food organisms, nevertheless S. aurata seems to be the most specialized. No significant dietary overlap was found, with S. aurata preferentially selecting gastropods and bivalves, while S. cantharus preferentially selected a wide variety of crustaceans and D. sargus a wider array, including crustaceans, gastropods and bivalves.     

Dioecy in the endemic genusDendrocacalia (Compositae) on the Bonin (Ogasawara) Islands

Dendrocacalia crepidifolia Nakai (Compositae, Senecioneae), the only species of this arboreal genus endemic to Haha Island in the Bonin Islands, was found to be dioecious. Male flowers differ from female ones in having a stunted style (style in female exserted from corolla and deeply bifurcating) and anthers filled with fertile pollen (anthers in the female lacking pollen). The size of the corolla and number of florets per head were similar between male and female flowers. The crown area of this arboreal species was also similar in male and female plants. The sex ratio was 0.55 male, not significantly different from 0.5. Both sexes produced nectar of similar sugar concentration (ca. 50%). The flowers are pollinated by feral honeybees (Apis mellifera), but they are thought to have been pollinated by small, lesshairy, endemic solitary bees before honeybees were introduced and subsequently became the dominant bee species on the island. The evolution of dioecy ofDendrocacalia on the island is thought to stem from the deleterious effects of inbreeding that are inherent in plants with geitonogamy. The increased geitonogamy on the island has resulted from increased woodiness (i.e., increased number of flowers per plant) and the original dependence on endemic bee pollinators, which are now endangered.     

Lipopolysaccharides (LPS) modulate the metabolism of deoxynivalenol (DON) in the pig

Pigs might be exposed to lipopolysaccharides (LPS) and deoxynivalenol (DON) at the same time, and both toxins are thought to interactively affect the intestinal barrier, the innate immune system, and the xenobiotics metabolism. Hence, we aimed at examining the single and combined effects of both toxins on nutrient digestibility and DON metabolism. For this purpose, barrows (26?±?4 kg) were fed restrictedly either a control diet (CON) or a diet contaminated with 3.1 mg DON/kg (DON) for 37 days. At day 37 of the experiment, pigs were infused intravenously for 60 min either with 100 μg DON/kg body weight (BW) (CON-DON), 7.5 μg LPS/kg BW (CON-LPS, DON-LPS) or a combination of both substances (CON-DON?+?LPS), or physiological saline (CON-CON, DON-CON). Blood samples were collected frequently until 3.25 h before the pigs were sacrificed for bile, liver, and kidney collection. The apparent digestibility of N-free extractives was significantly increased by 1 % when the DON-contaminated diet was fed. The total DON content in blood was significantly higher in endotoxemic pigs (34.8 ng/mL; CON-DON?+?LPS) when compared to the pigs infused with DON alone (18.8 ng/mL; CON-DON) while bile concentrations were not influenced by LPS. DON residue levels in liver and kidney closely reflected the treatment effects as described for blood. In contrast to DON infusion, the LPS challenge resulted in a significantly lower total DON concentration (13.2 vs. 7.5 ng/mL in groups DON-CON and DON-LPS, respectively) when the pigs were exposed to DON through the diet. The conjugation degree for DON in blood and bile was not influenced by treatments. In conclusion, endotoxemic pigs are characterized by higher DON residue levels in blood, liver, and kidney, probably by a compromised elimination.     

Removal of lead (Pb(2+)) by the cyanobacterium Gloeocapsa sp

Pb²⁺ removal ability of the viable-freshwater cyanobacterium Gloeocapsa sp. was studied in batch experiments. Gloeocapsa sp. was cultured in the Medium 18 with pH adjusted to 3, 4, 5, 6 and 7. Growth was subsequently determined based on the increase of chlorophyll-a content. Gloeocapsa sp. was able to grow at all pH levels tested, except at pH 3. Removal of Pb²⁺ was then further studied under pH 4. The results showed that Pb²⁺ concentration in the range of 0–20 mg L⁻¹ was not inhibitory to Gloeocapsa sp. growth but reduced its Pb²⁺ removal efficiency (by 4.5% when Pb²⁺ concentration increased from 2.5 to 20 mg L⁻¹). Pb²⁺ removal characteristics followed the Langmuir adsorption isotherm with the maximum removal capacity (q_max) of 232.56 mg g⁻¹. Adsorption of Pb²⁺ by this cyanobacterium followed the second order rate reaction and intraparticle diffusion was likely the rate-determining step. The initial rate of Pb²⁺adsorption during intraparticle diffusion was slower under light than under dark conditions, indicating that light probably slowed down the initial rate of intraparticle diffusion through the repulsion effects on cell membrane.     

Hatching of the winter eggs of the fruit-tree red spider mite (Panonychus ulmi (Koch))

Observations on the hatching of winter eggs of Panonychus ulmi (Koch) from apple orchards in England over the 5 years 1962-6 are described. Differences of 2–3 weeks between orchards in the date at which 50% hatch was reached were quite common and this was out of step with petal fall in the majority of orchards. There was a continuous range between early and late hatching populations and a tendency for the populations to hatch in the same order every year. In 1966 populations on Cox's Orange Pippin hatched earlier than those on Worcester Pearmain but the difference was unlikely to be of practical importance. Neither recording accumulated day degrees for populations hatched out-of-doors nor hatching in an incubator after chilling was considered to give a sufficiently reliable forecast of 50% hatch but observations in 1966 suggested that this might be predicted from the total eggs hatched in an incubator expressed as a percentage of total healthy eggs.     

Trabecular barriers (FRENULAE) of the extracapsular clefts (38563).

Ferrocyanide was perfused through the vascular system of the isolated legs of 10 dogs. Ferric ion was then injected intramuscularly (not intravascularly) into the leg. The injected materials spread along the trabeculae of the tissues, rupturing the sheets of fibrous connective tissue (frenulae) inpeded the movement of materials in the trabeculae. The barriers consist of sheets of connective tissue which insert on adjacent fibrous capsules. The capsules enclose each cluster of muscle, glandular or other cells. These barriers appear to function in conjunction with the lymphatic drainage system.     

Composition of the milks of the bottlenose dolphin (Tursiops trucatus) and the Florida manatee (Trichechus manatus latirostris)

Milk samples from four individual bottlenose (Tursiops truncatus) and two Florida manatees (Trichechus manatus latirostris) of known lactation stages were analyzed for protein, carbohydrate and lipid composition, as well as for activity levels of alpha-lactalbumin, the regulatory protein of lactose synthase. The milk from both species had relatively high protein and lipid levels, as reported previously for other marine mammals. The major proportion of the lipid was in the form of triglycerides. Dolphin milk contained an average of 2.2% neutral sugars, which was essentially all in the form of lactose, as determined by several criteria. Manatee milk samples contained 0.6% of neutral sugars, and a larger proportion (about 2%) of amino sugars. Lactose was not detected by enzymatic assay or paper chromatography, but HPLC analysis indicated the presence of low levels of lactose together with two components that were tentatively identified as oligosaccharides. alpha-Lactalbumin activity, determined by assay with bovine galactosyltransferase, was found in both dolphin and manatee milk. The level in dolphin milk was comparable with that found in bovine and other milk, but the level in the manatee was less than 10% of that in the dolphin.     

Aflatoxin production on the pits (seeds) of the date palm (Phoenix dactylifera L.)

Pits —a by-product of the utilization of date fruits, are widely used as components of animal feeds, but an incident of aflatoxicosis in camels fed rations containing date pits has caused concern in the Gulf Region. This present study has shown that date pits can support aflatoxin production when inoculated withAspergillus parasiticus (IMI 91019b) and that variety and/or stages of maturation within a given variety can affect the final level of aflatoxin in the material. In one variety, Lulu, aflatoxin production was 44.5,38.7 and 21.0 ?g/g in pits taken from the first three stages of ripening namelyKimri, Khalal andRutab, but no significant aflatoxin production was noted at the fully-ripeTamr stage. Moisture content was considered to be the most important factor with respect to the capacity of the mould to synthesise aflatoxin in date pits.     

Bivalve immunity: comparisons between the marine mussel (Mytilus edulis), the edible cockle (Cerastoderma edule) and the razor-shell (Ensis siliqua)

Much of the current knowledge concerning bivalve immunology and immunotoxicology has come from studies on the mussel genus, Mytilus, or from the American oyster, Crassostrea virginica. Following a major oil spill, it was observed that the marine mussel, Mytilus edulis, underwent significant immunosuppression but no oil-induced mortalities, while in contrast, mass mortalities were noted in the edible cockle, Cerastoderma edule, and the razor-shell, Ensis siliqua. A study comparing immune cells and functions in these three species was initiated (i) to assess whether M. edulis was a representative model species and (ii) to provide baseline data on immunity in two common species, which had previously received little or no attention in this respect. While all three species shared similar cell types, their lectin-binding and enzyme cytochemistry differed considerably. M. edulis had significantly different proportions of haemocytes binding with the lectins concanavalin A, wheatgerm agglutinin and Helix pomatia agglutinin and stained positive for eight enzymes, compared with only five in C. edule and three in E. siliqua. In terms of immune function, M. edulis haemocytes were much more active in phagocytosis and superoxide generation than haemocytes of the other two species. The results show that immune cells and functions differed extensively in these three closely related species, with M. edulis showing a much higher level of immunological vigour that may be linked to its considerable resilience to adverse environmental conditions. This suggests that M. edulis may not be particularly representative of the bivalves in terms of immune reactivity and that a wider range of species should be included in studies of molluscan immunotoxicology.     

Metabolic costs of the predation strategy of the spider Pardosa amentata (Clerck) (Lycosidae)

Summary Pardosa amentata adopts a sit-and-wait predation strategy with periodic changes of site. The metabolic costs of this strategy were evaluated using a Gilson respirometer. The respirometer was run at the mean temperatures prevailing month by month in the litter layer from which the experimental animals were collected and equations relating standard respiration rate to spider weight were established for each temperature. The mean value of b, the exponent relating weight to respiration rate, was 0.8011. Active respiration rate was determined at each temperature by using larger experimental flasks containing small glass beads which, in conjunction with the shaker mechanism on the respirometer, ensured that the spiders in the respirometer flasks maintained a fairly consistent level of locomotory activity. It was found that the measured active respiration rate was on average 3.17 times the standard rate. The two respiration rates were combined in the appropriate proportions to calculate the daily energy expenditure of an adult spider exhibiting its normal pattern of activity at different temperatures. It is shown that as locomotory activity is very limited in duration in P. amentata, the associated active respiration rate accounts for only a small proportion of daily respiratory energy losses, 0.36% at 5°C, 0.69% at 10°C, and 1.01% at 15°C.     

Larval-rearing and growout of the red porgy (Pagrus pagrus) in the Riopesca hatchery (Greece)

Juveniles of red porgy (Pagrus pagrus 1758 L.) were experimentallyproduced in RIOPESCA hatchery during Spring 1992–95. Wild broodstock,weighing from 500 to 1000 g, was caught and brought to the hatchery insummer 1991. They were placed in a 30 m³ rectangular outdoorbroodstock tank with a sea-water flow of 5 m³ per hour.Salinity ranged from 3.9 to 4.1%, temperature from 13 to25°C , the stocking density was 4 kg m^–3,and the sex ratio was 1:1. The females spawned spontaneously in captivity producing approximately 200 000 eggs per kg of body weight. The percent offertilization was between 85–95%. Hatching was completed 85 hours later at 18 °C with a hatching percent of80–90%. The larvae were introduced into a 15 m³tank using green water (Nannochloropsis gaditana & Isochrysis galbana)and fed rotifers (Brachionus rotundiformis), Artemia salina nauplii andmetanauplii, and artificial food. After the end of the weaning period (day80 posthatch) the juveniles reached a weight of 1.4 g with a mean percentof survival of 10%. The fry were transferred to a cage site in which the growout proceeded without particular difficulties. The onlyproblem during growout was the skin coloration, that was darker than thatof wild porgies. Red porgies growth in our installations is satisfactory,with fry reaching 360 ± 12 g within 19 months, with a foodconversion rate of 1.8:1 , and a 6% mortality.     

Investigations on the triiodothyronine (T3)-specificity of thyrotropic (TSH) and gonadotropic (HCG) hormone in the unicellular Tetrahymena

In a previous experiment thyrotropin (TSH) increased the triiodothyronine (T3) production of Tetrahymena and chorionic gonadotropin (HCG) moderately overlapped the effect. At present the production of three amino acid type (histamine, serotonin, epinephrine) and one peptide (endorphin) hormones were studied under the effect of TSH or HCG, in tryptone-yeast (TY) or salt (Losina-Losinsky) medium. The duration of the effect was 10 min. TSH significantly (with almost 20%) decreased epinephrine production in TY medium and HCG similarly decreased epinephrine and increased histamine level. In salt solution TSH as well as HCG decreased the level of serotonin. The results show that at this low level of phylogeny TSH effect is not completely thyroxine-specific, however it is not general. HCG overlaps TSH effect on epinephrine and serotonin production, however its effect is broader. The experiments also demonstrate that the effect of pituitary trop-hormones can be bidirectional in Tetrahymena, as histamine level was increased and epinephrine level was decreased by HCG, in the same cells.     

Effects of the sex-linked dwarf gene (dw) on the expression of the muscular dystrophy gene (am) in chicken.

The sex-linked dwarf gene (dw) was introduced into companion muscular dystrophic (am) and nondystrophic (Am+) New Hampshire chicken lines to investigate influences of the dwarf gene on breast muscle weights, muscle fiber area, and the histological expression of muscular dystrophy. Dystrophic and nondystrophic chickens within dwarf or nondwarf genotypes were similar in body and carcass weights. Pectoralis and supracoracoideus muscle weights (as a percentage of adjusted carcass weight) were similar in nondystrophic dwarf and nondwarf males and females. In addition, pectoralis weight was similar in dystrophic dwarf males and dystrophic nondwarf males and females. However, pectoralis weight was significantly smaller in dystrophic dwarf females than in dystrophic nondwarf females, whereas supracoracoideus weight was significantly larger in dystrophic dwarf males than in dystrophic nondwarf males. Supracoracoideus weight was similar in dystrophic dwarf males and females and dystrophic nondwarf females. Pectoralis muscle fiber area was influenced by sex and by dwarf and dystrophy genotype. Muscle fiber area was larger in females than in males, smaller in dwarfs than in nondwarfs, and smaller in dystrophic than in nondystrophic muscles. Muscle fiber degeneration and adipose infiltration was more extensive in dystrophic than in nondystrophic females and males, and it was more advanced in dwarfs than in nondwarfs. Excessive acetylcholinesterase staining patterns were characteristic of dystrophic muscle in both dwarf and nondwarf genotypes. Nondystrophic and dystrophic dwarf male and female chickens are comparable substitutes for nondwarfs as biomedical models with respect to pectoralis histology, acetylcholinesterase staining pattern, and pectoralis muscle hypertrophy.     

Characterization of the recombinant copper chaperone (CCS) from the plant Glycine (G.) max

The goal of the present work was to characterize the recombinant copper chaperone (CCS) from soybean. Very little is known about plant copper chaperones, which makes this study of current interest, and allows for a comparison with the better known homologues from yeast and humans. To obtain sizeable amounts of pure protein suitable for spectroscopic characterization, we cloned and overexpressed the G. max CCS chaperone in E. coli in the presence of 0.5 mM CuSO(4) and 0.5 mM ZnSO(4) in the broth. A pure protein preparation was obtained by using two IMAC steps and pH gradient chromatography. Most of the proteins were obtained as apo-form, devoid of copper atoms. The chaperone showed a high content (i.e., over 40%) of loops, turns and random coil as determined both by circular dichroism and homology modelling. The homology 3-D structural model suggests the protein might fold in three structural protein domains. The 3-D model along with the primary structure and spectroscopic data may suggest that copper atoms occupy the two metal binding sites, MKCEGC and CTC, within the N-terminal domain I and C-terminal domain III, respectively. But only one Zn-binding site was obtained spectroscopically.     

Identification of the areas of endemism (AOEs) of the genus Acantholimon (Plumbaginaceae) in Iran

Abstract

This study was conducted to identify areas of endemism for Acantholimon species using parsimony analysis of endemicity (PAE) and to detect endemic species richness of the genus in the region. The results obtained from the two methods used in this study were used in determining the priorities for the conservation of Acantholimon species in Iran. The distribution database of 62 endemic species belonging to this genus was formed by 1250 georeferenced observations in Iran. The study area was divided into 1?×1? grids of operative geographical units (OGUs) and the species?×?area matrix including presence/absence data was created. The endemic species richness was calculated using circular neighborhood with a radius of 50?km in 10?×?10?km² raster cells using DIVA-GIS software. The results of PAE analysis have shown four areas of endemism (AOEs) in Iran. AOE1: including Alborz and Zagros mountains, the mountains of central Iran. AOE2 and AOE3 are located in Khorassan subregion and AOE4 contains parts of western Iran. The map of endemic species richness indicated that the highest number of endemic species occurs in central Alborz region as well as Kerman, Chahar-Mahal and Bakhtiari, and Isfahan provinces.     

Seasonal changes in the circadian activity rhythm of light-dark (LD) and completely dark (DD) regimen in the mouse submandibular gland in the presence of light-dark (LD) and completely dark (DD) regimen

Influence of seasons on circadian activity changes and the influence of one and six weeks of DD upon these changes of acid phosphatase (AP) and beta-acetylglucosaminidase (AM) was studied in the submandibular gland of sexually mature male mice. Total enzyme activity was determined in tissue homogenates at four-hour intervals in March, June, October, and February under standard LD12/12 conditions and after one and six weeks of the DD regime. The rhythms were analysed according to cosinor method. Under constant lighting conditions the seasonal differences in the AM circadian activity rhythm were found. AP activity was considerably less influenced by seasonal changes. Both enzyme activity changes were independent of each other and each rhythm was differently influenced by DD. In the case of AM the most pronounced circadian activity changes had the highest amplitude and mesor occurred in summer. The strongest influence of DD upon this enzyme activity rhythm was observed in spring and summer especially after the first week, after six weeks the acrophase returned to the LD group value (spring). In autumn and winter the reaction to DD was different to that of summer and spring. For AP the circadian changes of activity were non-rhythmic in spring, whereas in all other seasons the acrophases occurred almost at the same time in the afternoon. In DD the activity rhythm significantly changed after six weeks. In all seasons, except spring the circadian rhythm of activity was not observed after six weeks of DD. An attempt was made to explain the observed results by the certain kind of genetic memory present in laboratory animals the neurohormonal system of which is influenced by seasonal changes.     

Mapping the distribution of the telomeric sequence (T(2)AG(3))(n) in rock wallabies,Petrogale (Marsupialia: Macropodidae), by fluorescence in situ hybridization. ii. the lateralis complex

The distribution of the conserved vertebrate telomeric sequence (T(2)AG(3))(n) was examined by fluorescence in situ hybridization in the six Petrogale (rock wallabies) taxa of the lateralis complex. As expected, the (T(2)AG(3))(n) sequence was located at the termini of all chromosomes in all taxa. However, the sequence was also present at several nontelomeric (viz., interstitial and centromeric) sites. The signals identified were associated with either ancient rearrangements involved with the formation of the 2n = 22 plesiomorphic macropodine karyotype or more recent rearrangements associated with karyotypes derived from the 2n = 22 karyotype. Interstitial (T(2)AG(3))(n) signals identified on chromosomes 3 and 4 in all six species of the lateralis complex and a large centromeric signal identified on chromosome 7 in the five subspecies/races of P. lateralis appear to be related to the more ancient rearrangements. Subsequent chromosome evolution has seen these signals retained, lost, or amplified in different Petrogale lineages. Within the lateralis complex, in two submetacentric chromosome derived by recent centric fusions, the telomeric sequence was identified at or near the centromere, indicating its retention during the fusion process. In the two taxa where chromosome 3 was rearranged via a recent centromeric transposition to become an acrocentric chromosome, the telomeric signal was located interstitially.     

Molecular weight dependence of the poly(L-lactide)/poly(D-lactide) Stereocomplex at the air-water interface

The molecular weight dependence of poly(L-lactide)/poly(D-lactide) (PLLA/PDLA) stereocomplex behavior at the air-water interface was studied by surface pressure-area (pi-A) isotherms and atomic force microscopy (AFM). It was found that the compression-induced sterecomplexation of a PDLA/PLLA equimolar blend with high molecular weight (M(w) = 1 x 10(6) and 9.8 x 10(5), respectively) could occur at the air-water interface. This result is in marked contrast with the stereocomplexation of PDLA/PLLA blends in the bulk from the melt or in solutions, where the homocrystallites of either PLLA or PDLA rather than stereocomplex crystallites will be formed preferentially when the molecular weights of both polymers are higher than 1 x 10(5). Unexpectedly, the Langmuir-Blodgett behavior of the PDLA/PLLA blend with lower molecular weight (M(w) = 4 x 10(3) and 3.2 x 10(3), respectively), which should be favored in the stereocomplex, was distinct from that of other higher molecular weight blends. AFM images clearly disclosed for the first time the morphological changes of the equimolar blends of PLLA and PDLA at the air-water interface induced by increasing the surface pressure of the monolayer. Of particular note, the bilayer mechanism for the plateau in the isotherm was directly verified by the AFM height images.