Effects of the Oral Administration of K<Subscript>2</Subscript>Cr<Subscript>2</Subscript>O<Subscript>7</Subscript> and Na<Subscript>2</Subscript>SeO<Subscript>3</Subscript> on Ca,Mg, Mn,Fe, Cu,and Zn Contents in the Heart,Liver, Spleen,and Kidney of Chickens

This study aimed to investigate the effects of selenium on the ion profiles in the heart, liver, spleen, and kidney through the oral administration of hexavalent chromium. Approximately 22.14 mg/kg b.w. K₂Cr₂O₇ was added to water to establish a chronic poisoning model. Different selenium levels (0.00, 0.31, 0.63, 1.25, 2.50, and 5.00 mg Na₂SeO₃/kg b.w.) around the safe dose were administered to the experimental group model. Ca, Mg, Mn, Fe, Cu, and Zn were detected in the organs through flame atomic absorption spectrometry after these organs were exposed to K₂Cr₂O₇ and Na₂SeO₃ for 14, 28, and 42 days. Results showed that these elements exhibited various changes. Ca contents declined in the heart, liver, and spleen. Ca contents also decreased on the 28th day and increased on the 42nd day in the kidney. Mn contents declined in the heart and spleen but increased in the kidney. Mn contents also decreased on the 28th day and increased on the 42nd day in the liver. Cu contents declined in the heart and spleen. Cu contents increased on the 28th day and decreased on the 42nd day in the liver and kidney. Zn contents declined in the heart and spleen. Zn contents increased on the 28th day and decreased on the 42nd day in the liver and kidney. Fe contents decreased in the heart and liver. Fe contents increased on the 28th day and decreased on the 42nd day in the spleen and kidney. Mg contents did not significantly change in these organs. Appropriate selenium contents enhanced Mn and Zn contents, which were declined by chromium. Conversely, appropriate selenium contents reduced Ca, Fe, and Cu contents, which were increased by chromium. In conclusion, the exposure of chickens to K₂Cr₂O₇ induced changes in different trace elements, and Na₂SeO₃ supplementation could alleviate this condition.     

Nuclease Digestion of Chromatin from the Eukaryotic Algae Olisthodiscus luteus,Peridinium balticum,and Crypthecodinium cohnii 1, 2

Chromatin from a uninucleate dinoflagellate, Crypthecodinium cohnii, a binucleate dinoflagellate, Peridinium balticum, and a chromophyte, Olisthodiscus luteus, was examined by nuclease digestion and the results were compared to those from vertebrates. Gel analysis of the products of staphylococcal (micrococcal) nuclease digestion revealed a DNA repeat unit of 220(±5) base pairs for O. luteus and 215(±5) for P. balticum. Limit digestion gave a core particle of 140 base pairs, revealing that these longer repeat sizes are due to longer linker regions. No repeating subunit structure was found upon electrophoresis of digests of C. cohnii nuclei. Examination of the DNA fragments produced by DNAse I digestion of nuclei isolated from P. balticum and O. luteus showed the same ladder of ten base multiples as seen in chromatin from other eukaryotes. Examination of the kinetics of digestion by DNAse II of Peridinium chromatin revealed less susceptibility when compared to DNAse I digestions while 70% of Olisthodiscus chromatin and 35% of C. cohnii chromatin was sensitive to DNAse II. These data, taken together with previous results from Euglena, indicate that while algal chromatin is similar to that of higher eukaryotes in regard to DNAse I and II action, it differs in that the linker DNA is longer. In addition, the Hl-like histone from O. luteus and P. balticum is located in the linker DNA as in higher eukaryotes.     

Combined effects of the entomopathogenic fungus, <Emphasis Type="Italic">Paecilomyces fumosoroseus</Emphasis> Apopka-97, and the generalist predator, <Emphasis Type="Italic">Dicyphus hesperus</Emphasis>, on whitefly populations

The effects of intraguild interactions between Dicyphus hesperus Knight (Hemiptera: Miridae) and Paecilomyces fumosoroseus Apopka-97 (PFR-97^TM) (Wize) Brown and Smith (Ascomycota: Hypocreales) on Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) populations were investigated in tomato greenhouse microcosms. Conditions were established in which interference or synergy would most likely occur; namely, a high number of available whiteflies were combined with large numbers of both D. hesperus and PFR-97^TM. We measured live whitefly density in a factorial repeated measures experiment where plants were provided or withheld releases of D. hesperus and/or applications of PFR-97^TM for 6 weeks. Releases of D. hesperus were made at a rate of 10 adults/plant during the first and third week and PFR-97^TM suspensions were applied with a backpack sprayer at a rate of 18 × 10⁷, 1.3 × 10⁷ and 1.2 × 10⁷ viable blastospores/ml during the first, third and fourth week, respectively. Results revealed a non-significant interaction effect between D. hesperus and PFR-97^TM, indicating that their actions were independent. Individual whitefly reductions of 48% and 35% were achieved by PFR-97^TM and D. hesperus, respectively. Collectively, the natural enemies reduced whitefly densities by 62% relative to the controls. The density of D. hesperus adults was unaffected by multiple applications of PFR-97^TM. These results suggest that the combination of generalist entomopathogenic fungi and generalist predators has the potential to cause increased pest mortality despite evidence of minimal interference.     

Late Carboniferous palynostratigraphy of the Itararé Subgroup, northeastern Paraná Basin, Brazil

A new biozonation is proposed for the Late Carboniferous strata of the northeastern Paraná Basin (São Paulo and Paraná States), based on well-preserved palynological assemblages recovered from outcrops and core samples retrieved from the Itararé Subgroup. Assemblages include forty-nine species of trilete spores and twenty-five pollen species. The oldest biozone, the Ahrensisporites cristatus Interval Zone (AcZ), in the basal portion of the Itararé Subgroup, includes eleven exclusive spore species, and is assigned a Pennsylvanian (late Bashkirian to Kasimovian) age. The overlying proposed biozone, the Crucisaccites monoletus Interval Zone (CmZ), dated late Pennsylvanian (Kasimovian to Gzhelian), ranges approximately from the top of the lower portion to the middle portion of the Itararé Subgroup, bears only one exclusive species of pollen. Both zones are characterized by the dominance of trilete spores and monosaccate pollen grains, including also few taeniate pollen grains. Furthermore, the basal Protohaploxypinus goraiensis Subzone of the Vittatina costabilis Interval Zone (VcZ) is broadly recognized for the first time in the upper portion of the Itararé Subgroup in the northeastern Paraná Basin. This subzone is attributed to the Early Permian (Early Cisuralian), and is characterized by the dominance of monosaccate pollen grains, a significant increase of taeniate grains (mainly Protohaploxypinus spp.), apart from the appearance of polyplicate pollen (Vittatina spp.). Reference sections and the main characteristics of the two new zones (AcZ and CmZ) are presented, along with a preliminary palynological correlation and discussion on their ages.     

On the presence of the Australian redclaw crayfish, <Emphasis Type="Italic">Cherax quadricarinatus</Emphasis>, in Mexico

The first reports of wild caught Australian redclaw crayfish from Mexico, in the states of Morelos and Tamaulipas, are presented. Redclaw crayfish were first brought to Mexico in 1995 to initiate experimental cultures at several research centers. In the following years a number of private ventures started commercial cultures, several of which in the states of Morelos and Tamaulipas are thought to have been the sources for the wild populations recorded in this study. The farms that acted as the original sources have not been operating for at least 2 years. In Morelos, high densities and all size classes of redclaws, including ovigerous females, were captured in natural waterways; whereas in Tamaulipas they were found at four sites occurring in irrigation canals in an agricultural district. The size attained by the wild redclaws, the abiotic conditions in which they were found and the potential for spread within the drainage systems of the Balsas and Tamesi Rivers are discussed.     

Fullerenes C<Subscript>60</Subscript>, antiamyloid action,the brain,and cognitive processes

A short review of investigations along a new line: the antiamyloid action of fullerenes C₆₀ and correction of disturbed cognitive processes is presented. The prospects for the development of drugs based on fullerenes acting on the key molecular mechanisms at the early stage of Alzheimer’s disease are discussed.     

Phylogenetic placement of the enigmatic parasite, <Emphasis Type="Italic">Polypodium hydriforme</Emphasis>, within the Phylum Cnidaria

Background  

Polypodium hydriforme is a parasite with an unusual life cycle and peculiar morphology, both of which have made its systematic position uncertain. Polypodium has traditionally been considered a cnidarian because it possesses nematocysts, the stinging structures characteristic of this phylum. However, recent molecular phylogenetic studies using 18S rDNA sequence data have challenged this interpretation, and have shown that Polypodium is a close relative to myxozoans and together they share a closer affinity to bilaterians than cnidarians. Due to the variable rates of 18S rDNA sequences, these results have been suggested to be an artifact of long-branch attraction (LBA). A recent study, using multiple protein coding markers, shows that the myxozoan Buddenbrockia, is nested within cnidarians. Polypodium was not included in this study. To further investigate the phylogenetic placement of Polypodium, we have performed phylogenetic analyses of metazoans with 18S and partial 28S rDNA sequences in a large dataset that includes Polypodium and a comprehensive sampling of cnidarian taxa.     

Predator–prey naïveté, antipredator behavior,and the ecology of predator invasions

We present a framework for explaining variation in predator invasion success and predator impacts on native prey that integrates information about predator–prey naïveté, predator and prey behavioral responses to each other, consumptive and non‐consumptive effects of predators on prey, and interacting effects of multiple species interactions. We begin with the ‘naïve prey’ hypothesis that posits that naïve, native prey that lack evolutionary history with non‐native predators suffer heavy predation because they exhibit ineffective antipredator responses to novel predators. Not all naïve prey, however, show ineffective antipredator responses to novel predators. To explain variation in prey response to novel predators, we focus on the interaction between prey use of general versus specific cues and responses, and the functional similarity of non‐native and native predators. Effective antipredator responses reduce predation rates (reduce consumptive effects of predators, CEs), but often also carry costs that result in non‐consumptive effects (NCEs) of predators. We contrast expected CEs versus NCEs for non‐native versus native predators, and discuss how differences in the relative magnitudes of CEs and NCEs might influence invasion dynamics. Going beyond the effects of naïve prey, we discuss how the ‘naïve prey’, ‘enemy release’ and ‘evolution of increased competitive ability’ (EICA) hypotheses are inter‐related, and how the importance of all three might be mediated by prey and predator naïveté. These ideas hinge on the notion that non‐native predators enjoy a ‘novelty advantage’ associated with the naïveté of native prey and top predators. However, non‐native predators could instead suffer from a novelty disadvantage because they are also naïve to their new prey and potential predators. We hypothesize that patterns of community similarity and evolution might explain the variation in novelty advantage that can underlie variation in invasion outcomes. Finally, we discuss management implications of our framework, including suggestions for managing invasive predators, predator reintroductions and biological control.     

Immunohistochemical Localization of G Protein β1, β2, β3, β4, β5, and γ3 Subunits in the Adult Rat Brain

Abstract: The regional distributions of the G protein β subunits (Gβ1–β5) and of the Gγ3 subunit were examined by immunohistochemical methods in the adult rat brain. In general, the Gβ and Gγ3 subunits were widely distributed throughout the brain, with most regions containing several Gβ subunits within their neuronal networks. The olfactory bulb, neocortex, hippocampus, striatum, thalamus, cerebellum, and brainstem exhibited light to intense Gβ immunostaining. Negative immunostaining was observed in cortical layer I for Gβ1 and layer IV for Gβ4. The hippocampal dentate granular and CA1–CA3 pyramidal cells displayed little or no positive immunostaining for Gβ2 or Gβ4. No anti-Gβ4 immunostaining was observed in the pars compacta of the substantia nigra or in the cerebellar granule cell layer and Purkinje cells. Immunoreactivity for Gβ1 was absent from the cerebellar molecular layer, and Gβ2 was not detected in the Purkinje cells. No positive Gγ3 immunoreactivity was observed in the lateral habenula, lateral septal nucleus, or Purkinje cells. Double-fluorescence immunostaining with anti-Gγ3 antibody and individual anti-Gβ1–β5 antibodies displayed regional selectivity with Gβ1 (cortical layers V–VI) and Gβ2 (cortical layer I). In conclusion, despite the widespread overlapping distributions of Gβ1–β5 with Gγ3, specific dimeric associations in situ were observed within discrete brain regions.     

Theoretical study of the effects of substituents (F,Cl, Br,CH<Subscript>3</Subscript>, and CN) on the aromaticity of borazine

This paper presents a theoretical study of the effects of substituents (F, Cl, Br, CH₃, and CN) on the aromaticity of borazine (B₃N₃H₆), using density functional theory (DFT) and the Hartree-Fock (HF) method. The calculations to optimize the geometries, structural properties, and vibrational frequencies were performed using the same 6–311G(d,p) and 6–311++G(d,p) basis sets, comparing the methods with experimental results. In the analysis of the NICS_ZZ values, it was found that that replacing the hydrogen atoms by halogen atoms (F, Cl, and Br) and CH₃ reduced the aromaticity of the borazine molecule, while use of the CN group resulted in NICS_ZZ values (0.9–2.0 Å) very close to those of borazine, presenting the following order of increasing aromaticity: B₃N₃H₃-(Br)₃?<?B₃N₃H₃-(Cl)₃?<?B₃N₃H₃-(F)₃?<?B₃N₃H₃-(CH₃)₃?<?B₃N₃H₆ ~ B₃N₃H₃-(CN)₃. All the spectra of the compounds showed only the presence of transition peaks distant from the UV region, reflecting the large energy difference between the HOMO and LUMO orbitals. After the substitution of the borazine ring, all the compounds presented an intensification of the spectrum, with a shift of the maximum absorbance toward red, indicative of a bathochromic effect. There was a direct inverse relation between the energy gap and the maximum wavelength of the compounds.     

Report of the 5<Superscript>th</Superscript> International Symposium <Emphasis Type="Italic">Biology and Taxonomy of Green Algae</Emphasis>, Smolenice,Slovakia, June 25–29, 2007

The International Symposium Biology and Taxonomy of Green Algae V was held at the Congress Centre of the Slovak Academy of Sciences in Smolenice, Slovakia, June 25–29, 2007. The symposium was attended by 61 phycologists from 19 countries of Europe (17), Asia (2) and America (4). Thirty-three lectures were given and 28 poster presentations exhibited and discussed. The scientific programme dealt with the taxonomy, ecology, physiology and genetics of green algae. One mid-symposium excursion to the Záhorie region (city of Skalica) was organized.     

Conklin, Joyce, and the Wannaknów

Verbal play among the Hanunóo of Mindoro is surprisingly similar to that practiced by the Dubliners of Ireland. The similarity invites a comparison of the work habits of their scribes: the ethnographer Harold Conklin and the novelist James Joyce. A Joycean version of an ethnography of the Wannaknow is presented as a textual focus for the comparison.     

Effect of glucose,maltose, soluble starch,and CO<Subscript>2</Subscript> on the growth of the hyperthermophilic archaeon<Emphasis Type="Italic"> Pyrococcus furiosus</Emphasis>

The hyperthermophilic archaeon Pyrococcus furiosus was cultivated in batch and continuous fermentations on different carbon substrates. The cultivation of P furiosus on soluble starch as the only carbon source resulted in cell densities three times higher than in cultivations on maltose, 1.06 x 10(10) cells/ml compared to 3.4 x 10(9) cells/ml. The yield coefficient, Y(x/y) = 0.12 g/g, and the growth rate, mu = 0.33 h(-1), were almost equal on soluble starch and on maltose, but on glucose no growth could be detected. An inhibitory effect of glucose, when added to other carbon substrates, also could not be found. Isobutyric and isovaleric acid were detected as novel metabolites produced by P. furiosus. Inhibitory effects of these acids, as well as of the well-known products acetic acid, propionic acid, and alanine, could be precluded. Concentrations of 10% CO2 in the gas supply respective to the exhaust gas enhanced the growth of P furiosus significantly. The maximum cell number was two orders of magnitude higher than was observed with pure nitrogen. Further increase of the CO2 concentration up to 100% had no significant effect on the growth of P. furiosus.     

Aberrations of the alarm call of the steppe marmot, <Emphasis Type="Italic">Marmota bobak</Emphasis> (Rodentia,Sciuridae)

Aberrations, or deviations from the normal type of alarm call, have been studied in the steppe marmot. One regular and several rare aberrations have been identified. The regular aberration manifests itself in all six populations studied, from the Kharkov Region in the west to the eastern border of the Orenburg Region in the east, with its frequency in the populations varying in different years from 10 to 66%. Rare aberrations occur sporadically and not in all populations.     

Fructose,uricase, and the Back‐to‐Africa hypothesis

In the Middle Miocene (approximately 17 to 12 Ma) at least two radiations of fossil apes from East Africa into Eurasia occurred, and, while controversial, some paleoanthropological studies suggest that one of the Eurasian lineages may have returned to Africa to evolve into humans and the African apes. Here, we present a novel argument supporting this hypothesis. Specifically, the global cooling that occurred in the middle Miocene rendered hominoids living in Europe at risk for starvation as seasonal climate change resulted in less availability of fruits during the winter months. During this time, a mutation in uricase occurred in early hominids that resulted in a rise in serum uric acid. Uric acid has been found to potentiate the effect of fructose to increase fat stores, suggesting that the mutation provided a survival advantage. Such a survival advantage would have been less likely to occur in Africa, where the continued presence of tropical rainforests would have been more likely to provide food throughout the year. Furthermore, Miocene apes in Europe were in protected sites where geographic isolation could have allowed the uricase mutation to be rapidly expressed in the entire population. While speculative, we suggest that the uricase mutation supports an extra‐Africa origin of humans.     

Effects of germanium dioxide,an inhibitor of diatom growth,on the microscopic laboratory cultivation stage of the kelp, <Emphasis Type="Italic">Laminaria saccharina</Emphasis>

The kelp, Laminaria saccharina, is an economically and biologically valuable seaweed used in integrated multi-trophic aquaculture. The development of the initial microscopic phase of the life cycle of this species is carried out in the laboratory. A treatment of germanium dioxide (GeO₂) can be applied to algal laboratory cultures to inhibit the growth of contaminating diatoms. Previous studies reported inhibitory effects also affecting the macroscopic stage of the life cycle of L. saccharina, the sporophyte, but the effects on the microscopic gametophytic life stage are unknown. To determine the effects, cultures of L. saccharina were treated with varying concentrations of GeO₂ and the resulting lengths and surface area of the juvenile sporophytes produced were measured. It was determined that GeO₂ follows a typical dose-effect pattern, increasing the growth rate of juvenile sporophytes until a critical point at which an inhibitory effect was observed. To obtain juvenile sporophytes ready for deployment to aquaculture sites in the shortest time and to successfully reduce diatom contamination, it was determined that a concentration between 0.10 and 0.50mL of GeO₂ per litre of seawater, applied at day 8, was the most efficient.     

A review of the grassflies of the genus <Emphasis Type="Italic">Meromyza</Emphasis> Meigen, 1830 (Diptera,Chloropidae) of the Palaearctic fauna,with a key to the species,analysis of synonymy,host specialization,and geographical distribution: Part 1

The first part of the paper includes a key to 72 Palaearctic and Oriental species of the genus Meromyza.