Chemical evolution in the Asteraceae. The Oxidation-Reduction mechanism and production of secondary metabolites

This work describes the application of partial least squares (PLS) regression to variables that represent the oxidation data of several types of secondary metabolite isolated from the family Asteraceae. The oxidation states were calculated for each carbon atom of the involved compounds after these had been matched with their biogenetic precursor. The states of oxidation variations were named oxidation steps. This methodology represents a new approach to inspect the oxidative changes in taxa. Partial least square (PLS) regression was used to inspect the relationships among terpenoids, cournarins, polyacetylenes, and flavonoids from a data base containing approximately 27,000 botanical entries. The results show an interdependence between the average oxidation states of each class of secondary metabolite at tribe and sub tribe levels.

Genetic characterization of native and introduced populations of the neotropical cichlid genus Cichla in Brazil

A molecular phylogenetic analysis based on mitochondrial 16S ribosomal DNA and Control Region sequences from native and introduced populations was undertaken, in order to characterize the introduction of Cichla (peacock bass or tucunaré) species in Brazil. Mitochondrial DNA haplotypes found in introduced fish from Minas Gerais state (southeastern Brazil) clustered only with those from native species of the Tocantins River (Cichla piquiti and C. kelberi), thereby suggesting a single or, at most, few translocation acts in this area, even though with fish from the same source-population. Our study contributes to an understanding of the introduction of Cichla in regions of Brazil outside the Amazon basin, and adds phylogenetic data to the recently describe Cichla species, endemic from the Tocantins-Araguaia basin.

Reproductive cycle of the Neotropical cichlid yellow peacock bass Cichla kelberi: A novel pattern of testicular development

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of addition of a bird repellent to fish diets on their growth and bioaccumulation

The effects of adding the nonlethal bird repellent methyl anthranilate (MA), at levels of 100 and 1000 mg/kg, to fish feed on the bioaccumulation and growth of juvenile (10 g) hybrid striped bass (Morone chrysops x M. saxatilis) and juvenile (1g) African cichlid fish Aulonocara jacobfreibergi were investigated under laboratory conditions. The bird repellent did not have any effect on the fish growth or survival over a period of 6 weeks. MA residues at low levels of 11.2 ± 2.6 mg/g were found in lipophilic tissues (liver) of MA-fed fish. Control fish, which had no MA added to their diet, had a much lower level of 0.6 ± 0.3 mg/g MA in their liver. Fish muscle was found to contain negligible MA residues, while the outer body surface mucus did not contain any MA. Following a 6-week depuration period, during which the previously MA-fed hybrid striped bass were fed a feed to which no MA was added, the levels of MA residues detected were reduced by one order of magnitude.

Hematological parameters and phagocytic activity in fat snook (Centropomus parallelus) bred in captivity

The objective of this work was to determine the hematological parameters and the phagocytic capacity of peritoneal macrophages of fat snook related to sex, stage of gonadal maturation and seasonal cycle. Blood was collected from 135 animals (78 females and 57 males) and used for determinations of: erythrocyte number, hematocrit, hemoglobin, erythrocyte indices mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC), total and differential leukocyte counts, and thrombocyte count. The phagocytic capacity and phagocytic index were determined after Saccharomyces cerevisiae inoculation in the peritoneal cavity of the animals. The hematological results according to sex showed that the erythrocyte, total leukocyte and thrombocyte counts were statistically higher in males than females, with the latter showing a higher MCV. Concerning to erythrocyte count, hematocrit and hemoglobin concentration analyzed separately by sex and stage of gonadal maturation, males were found to have significantly elevated values in the mature stage and decreased levels in the resting stage. The results of the erythrocyte and leukocyte series, thrombocytes and phagocytic activity related to seasonal cycle showed significant differences in both sexes, where hematocrit and hemoglobin concentration were lower in winter and higher in the other seasons, mean corpuscular volume was higher in the summer and lower in the winter and fall, total leukocytes and thrombocytes lower in the spring and higher in the fall, lymphocytes low in the winter and summer and high in the spring and phagocytic capacity and phagocytic index high in the summer and low in the winter and fall. The results showed that the hematological values in males are statistically higher than those in females, the erythrocyte values in males increase with the progression of gonadal maturation and that winter is the season of the year least favorable for hematological and phagocytic responses for survival of fat snook kept in captivity. The parameters studied could be utilized in the evaluation of the health status of this species in captivity. (C) 2012 Elsevier Ltd. All rights reserved.

Gonadal steroids levels and vitellogenesis in the formation of oocytes in Prochilodus lineatus (Valenciennes) (Teleostei: Characiformes)

The objective of this study was to obtain information about the possible mechanisms related to poor reproductive performance in tropical rheophilic fish. To that effect, cages (Cs) and earthen ponds (EPs) were used as experimental systems to provide unsuitable and suitable conditions, respectively, for curimbata (Prochilodus lineatus) breeders. Fish were maintained under experimental conditions for 18 months, and during this period females were randomly sampled every two months for biometric analysis (n=30), blood (n=5/sampling) and ovary (n=5/sampling). After this period EPs females (EPFs) and Cs females (CFs) were submitted to the induced breeding experiments. The results showed that rearing curimbata for such long time in a cage at this stocking density, reduces its growth, plasma E2 levels and vitellogenesis. During vitellogenesis, the mean plasma estradiol levels of CFs were three times lower than those of EPFs (P<0.01). CFs presented poorer results than EPFs for all the examined parameters of reproductive performance. Taken together these data showed that the reduced estradiol levels during vitellogenesis (and the consequently less intense transition from the previtellogenic to vitellogenic phase) and reduced amounts of yolk are mechanisms associated with the formation of low quality oocytes and shortened and delayed breeding season in this species. Moreover, our data showed that the onset of vitellogenesis (six months before the spawning season) must be considered as a key period related to the formation of oocytes of good quality, and adequate management should be provided throughout the year.

Fatty acids as a tool to compare cachara (Pseudoplatystoma reticulatum) (Siluriformes: Pimelodidae) and hybrid (Pseudoplatystoma corruscans x Pseudoplatystoma reticulatum) larvae during early development

In this study, we investigated the physiological alterations during ontogeny for cachara (Pseudoplatystoma reticulatum) and their hybrid larvae (Pseudoplatystoma corruscans x P. reticulatum) using lipids and fatty acids as physiological tools to elucidate the basis for differences in these groups' productivity in an industrial setting. Eggs and larvae samples were collected during January and February of 2008 in the city of Bandeirantes, MS, and were divided into three primary phases: phase I (0-16 h after fertilization); phase II (24 h after fertilization to 6 days after fertilization); and phase III (7-25 days after fertilization). The larvae of both groups showed a high degree of similarity, suggesting that the hybrid larvae showed a high level of heritability from the cachara broodstock. Analysis of the total lipid content provided evidence that there is no alteration in lipid concentration during ontogeny for both groups (i.e., the cachara and hybrids). However, the fatty acid profile showed that during the endogenous feeding period (phase II), when the larvae must use the energy reserves from the mother, the cachara larvae used mainly monounsaturated fatty acids for development. This is typical for most fish species, though notably, the hybrids preferentially used saturated fatty acids. Furthermore, certain specific changes demonstrate unique patterns of energy utilization and structural substrates, which may aid in elucidating the empirical differences reported by fish farmers (i.e., that the hybrids perform better than cacharas in captivity).

The influence of captive breeding on the fatty acid profiles of Salminus hilarii (Characiformes: Characidae) eggs and larvae

In addition to the strong influence of the broodstock diet on the development and survival of offspring, domestication may also interfere with the larval life success. We obtained eggs from wild and domesticated Salminus hilarii females and domesticated males. Wild females were caught in the Tiete River and tributaries, and the domesticated females were born three years before the beginning of the experiment in the Ponte Nova Fish Farm. Animals from both groups were fed with the same feed to exclude feed variables. The eggs and larvae were sampled at 0, 8, 16, and 28 h after spawning (HAS), with the last sampling (28 HAS) coinciding with hatching time. After hatching, samplings proceeded at 32, 48, 66, and 96 HAS, with the last sampling (96 HAS) corresponding to the end of yolk sac consumption. Finally, the last experimental period was during the larvae exogenous feeding phase, at 102, 118, 166, and 214 HAS. Our data revealed that domestication of S. hilarii females influenced fatty acid (FA) metabolism during embryo and larva development. However, the structure of membrane phospholipid FA remained mostly stable, with changes principally in the neutral fraction. When the external conditions, mainly water and feed quality, remained constant, domestication of S. hilarii females did not significantly affect the structural FA composition but influenced the selectivity of consumption and/or storage of specific FA.

Percieved Organizational Efficacy in Internationalized Companies: Application of Competing Values Approach and Collective Efficacy

This dissertation focuses on “organizational efficacy”, in particular on employees’ beliefs of organizational capacity to be efficacious. Organizational efficacy is considered from two perspectives – competing values approach and collective efficacy, and evaluated in internationalized companies. The dissertation is composed of three studies. The data were collected in thirteen Italian companies on different stages of internationalization for a total number of respondents is 358. In the first study the factorial validity of the competing values instrument (Rohrbaugh, 1981) was investigated and confirmed. Two scales were used to measure collective efficacy: a general collective efficacy scale (Bohn, 2010), and a specific collective efficacy scale, developed following suggestions of Borgogni et al. (2001), it evaluates employees’ beliefs of efficacy of organizations in the international market. The findings suggest that competing values and collective organizational efficacy instruments may provide a multi-faceted measurement of employees’ beliefs of organizational efficacy. The second study examined the relationship between organizational efficacy and collective work engagement. To measure collective work engagement the UWES-9 (Schaufeli & Bakker, 2003) was adapted at the group level; its factor structure and reliability were similar to the standard UWES-9. The findings suggest that organizational efficacy fully predicts collective work engagement. Also we investigated whether leadership moderates the relationship between organizational efficacy and collective work engagement. We operationalized leadership style with MLQ (Bass & Avolio, 1995); the results suggest that intellectual stimulation and idealized influence (transformational leadership) and contingent reward (transactional leadership) enhance the impact of organizational efficacy on collective work engagement. In the third study we investigated organizational efficacy and collective work engagement in internationalized companies. The findings show that beliefs of organizational efficacy vary across companies in different stages of internationalization, while no significant difference was found for collective work engagement. Limitations, practical implications and future studies are discussed in the conclusion.

Design and in vitro characterization of highly sst2-selective somatostatin antagonists suitable for radiotargeting

Radiolabeled sst 2 and sst 3 antagonists are better candidates for tumor targeting than agonists with comparable binding characteristics (Ginj, M.; Zhang, H.; Waser, B.; Cescato, R.; Wild, D.; Erchegyi, J.; Rivier, J.; Mäcke, H. R.; Reubi, J. C. Proc. Natl. Acad. Sci. U.S.A. 2006, 103, 16436-16441.). Because most of the neuroendocrine tumors express sst 2, we used the known antagonists acetyl- pNO 2Phe (2)- c[ dCys (3)-Tyr (7)- dTrp (8)-Lys (9)-Thr (10)-Cys (14)]- dTyr (15)-NH 2 ( 1) (Bass, R. T.; Buckwalter, B. L.; Patel, B. P.; Pausch, M. H.; Price, L. A.; Strnad, J.; Hadcock, J. R. Mol. Pharmacol. 1996, 50, 709-715. Bass, R. T.; Buckwalter, B. L.; Patel, B. P.; Pausch, M. H.; Price, L. A.; Strnad, J.; Hadcock, J. R. Mol. Pharmacol. 1997, 51, 170; Erratum.) and H-Cpa (2)- c[ dCys (3)-Tyr (7)- dTrp (8)-Lys (9)-Thr (10)-Cys (14)]-2Nal (15)-NH 2 ( 7) (Hocart, S. J.; Jain, R.; Murphy, W. A.; Taylor, J. E.; Coy, D. H. J. Med. Chem. 1999, 42, 1863-1871.) as leads for analogues with increased sst 2 binding affinity and selectivity. Among the 32 analogues reported here, DOTA- pNO 2Phe (2)- c[ dCys (3)-Tyr (7)- dAph (8)(Cbm)-Lys (9)-Thr (10)-Cys (14)- dTyr (15)-NH 2 ( 3) and DOTA-Cpa (2)- c[ dCys (3)-Aph (7)(Hor)- dAph (8)(Cbm)-Lys (9)-Thr (10)-Cys (14)]- dTyr (15)-NH 2 ( 31) had the highest sst 2 binding affinity and selectivity. All of the analogues tested kept their sst 2 antagonistic properties (i.e., did not affect calcium release in vitro and competitively antagonized the agonistic effect of [Tyr (3)]octreotide). Moreover, in an immunofluorescence-based internalization assay, the new analogues prevented sst 2 internalization induced by the sst 2 agonist [Tyr (3)]octreotide without being active by themselves. In conclusion, several analogues (in particular 3, 31, and 32) have outstanding sst 2 binding and functional antagonistic properties and, because of their DOTA moiety, are excellent candidates for in vivo targeting of sst 2-expressing cancers.