New approaches to basic population ecology studies: Revealing more complex patterns of a small Characidae that inhabit streams     

Diego Corrêa Alves  Lilian Paula Vasconcelos  Robson Marcelo Rossi  Sidnei E. Lima-Junior  Yzel R. Súarez 《Ecology of Freshwater Fish》2020,29(4):574-587

Bayesian inference was used to estimate the main population parameters (sex ratio, L₅₀, LWR and somatic growth) and to evaluate sexual dimorphism and growth patterns (isometric/allometric and monophasic/biphasic growth) of Astyanax paranae of the Upper Paraná River. This study brings three statistical differentials: (a) the reparametrisation of the logistic model as a function of L₅₀; (b) the reparameterisations of the LWR models based on the exponential of a piecewise linear regression to evaluate the hypotheses of polyphase growth; and (c) the first application of the recently proposed somatic growth models based only on length data to real data, as well as its expansion and generalisation. The models estimated L₅₀ of females at 37.75 mm and sex ratio at 1.4 females per male. LWR models showed that both sexes presented biphasic growth with a lower increase in weight for males in first stanza. In second stanza, both sexes presented a greater increase in weight. Growth models showed that the growth rates were low, equal for both sexes in early life and slightly higher for females after the eighteenth months old. The studied population inhabits streams, therefore being exposed to constraining conditions that can limit the expression of their whole growth potential since they prioritise energy allocation for reproduction and survival, including reducing L₅₀ in order to ensure the maintenance of the population. Finally, the complex biological patterns that arose from the proposed LWR and growth models demonstrated high potential and applicability for population studies.  相似文献   

Yield and nutritional evaluation of the banana hybrid ‘FHIA-18’ as influenced by phosphate fertilization     

Ana Carolina Batista Bolfarini  Fernando Ferrari Putti  Jackson Mirellys Azevêdo Souza  Marcelo de Souza Silva  Rafael Bibiano Ferreira  Magali Leonel 《Journal of plant nutrition》2020,43(9):1331-1342

Abstract

The ‘FHIA-18’ hybrid banana is an alternative for producers as it is resistant to Black Sigatoka and Panama disease. However, few studies report the nutritional requirement of this hybrid, especially phosphorus. It is known that the efficiency of phosphorus use can be improved, reducing the need for application, depending on the genotype cultivated. Therefore, this study aimed to evaluate the yield and mineral nutrition of ‘FHIA-18’ hybrid banana on phosphate fertilization. A banana orchard with the cultivar ‘FHIA-18’ was conducted on a Typical Red Latosol. Then, triple superphosphate fertilizer was applied on plants at 0, 20, 30, 40, 50, and 60?kg ha^?1?year^?1, over three productive seasons. At the time of flowering the macro and micronutrient contents of the leaves were evaluated. Subsequently, the nutrient contents of the fruits were evaluated. For this, fruit pulp samples from the third and fourth hands were collected. In addition, yield was estimated considering cluster mass and plant density. The following dose 36?kg ha^?1 of P₂O₅ year^?1 increased the content of phosphorus in the leaf, despite that banana hybrid cultivar FHIA 18 demanded 50% of the recommended fertilizer to achieve its maximum yield (29.4 t ha^?1?year^?1). Phosphate fertilization promoted significant changes in P, Ca, Cu, and Zn contents of leaves and fruits. Therefore, it is concluded that the mineral nutrition of banana ‘FHIA-18’ is affected by phosphate fertilization, as well as requiring less P than recommended to achieve higher yield.  相似文献   

Male genital organs of the black-crowned dwarf marmoset (Callibella humilis)     

Kássia Regina Aguiar Vieira  Hiuane Araújo Weber  Fabiano José Ferreira de Sant’Ana  Guilherme Reis Blume  Felipe Ennes Silva  Marcelo Ismar S. Santana 《Anatomia, histologia, embryologia》2023,52(2):163-171

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Special feature: alien pests threatening biodiversity of forest ecosystems     

Naoto Kamata  Kurt W. Gottschalk 《Journal of Forest Research》2007,12(5):325-326

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Regeneration of Polylepis australis Bitt. in the mountains of central Argentina     

Lucas Enrico  Guillermo Funes  Marcelo Cabido 《Forest Ecology and Management》2004,190(2-3):301-309

Polylepis australis woodlands range from northern to central Argentina. They support a high number of endemisms (both plants and animals) and constitute the main cover type in watersheds contributing to retain soil and catch water. Natural regeneration of P. australis in the Córdoba mountains, Argentina, was studied in two communities dominated by P. australis: shrublands and woodlands. The main objectives of the study were: (1) to characterize shrublands and woodlands in terms of physical (physical and chemical soil properties) and biological (Polylepis’ growth form, fern and moss cover) characteristics; (2) to describe P. australis’ soil seed bank and compare seedling and sapling establishment between both communities. The presence of seedlings as well as saplings was quantified, and soil samples were taken so as to characterize the seed bank.

Results showed significant differences in habitat conditions between shrublands and woodlands. Seedlings’ density was higher in the shrublands, while no differences appeared regarding the sapling numbers. A negative correlation was found between seedling numbers and total community cover as well as mosses and ferns cover. Seed density in the soil bank was higher in the woodlands, but overall seed viability was less than 5%. In the shrublands, the most critical stage of the species regeneration cycle was the transition from seedling to sapling, while in the woodlands the main “filter” occurred during seed germination. The low number of saplings observed in both units suggests a stagnation of P. australis regeneration, which could be translated into an unlikely expansion of the species throughout the Córdoba mountains.  相似文献   

Roraimine: a bisbenzylisoquinoline alkaloid from Cissampelos sympodialis roots     

de Lira GA  de Andrade LM  Florêncio KC  da Silva MS  Barbosa-Filho JM  Leitão da-Cunha EV 《Fitoterapia》2002,73(4):356-358

The roots of Cissampelos sympodialis yielded Roraimine (1), a novel bisbenzylisoquinoline alkaloid and liriodenine (2), a known oxoaporphine alkaloid.  相似文献   

Two Resistance Modes to Clover yellow vein virus in Pea Characterized by a Green Fluorescent Protein-Tagged Virus     

Andrade M  Sato M  Uyeda I 《Phytopathology》2007,97(5):544-550

ABSTRACT This study characterized resistance in pea lines PI 347295 and PI 378159 to Clover yellow vein virus (ClYVV). Genetic cross experiments showed that a single recessive gene controls resistance in both lines. Conventional mechanical inoculation did not result in infection; however, particle bombardment with infectious plasmid or mechanical inoculation with concentrated viral inocula did cause infection. When ClYVV No. 30 isolate was tagged with a green fluorescent protein (GFP) and used to monitor infection, viral cell-to-cell movement differed in the two pea lines. In PI 347595, ClYVV replicated at a single-cell level, but did not move to neighboring cells, indicating that resistance operated at a cell-to-cell step. In PI 378159, the virus moved to cells around the infection site and reached the leaf veins, but viral movement was slower than that in the susceptible line. The viruses observed around the infection sites and in the veins were then recovered and inoculated again by a conventional mechanical inoculation method onto PI 378159 demonstrating that ClYVV probably had mutated and newly emerged mutant viruses can move to neighboring cells and systemically infect the plants. Tagging the virus with GFP was an efficient tool for characterizing resistance modes. Implications of the two resistance modes are discussed.  相似文献   

Kinetics of energy source utilization in Boophilus microplus (Canestrini, 1887) (Acari: Ixodidae) embryonic development     

Campos E  Moraes J  Façanha AR  Moreira E  Valle D  Abreu L  Manso PP  Nascimento A  Pelajo-Machado M  Lenzi H  Masuda A  Vaz Ida S  Logullo C 《Veterinary parasitology》2006,138(3-4):349-357

The present work evaluates the kinetics of utilization of the main potential energy sources throughout the embryonic developmental stages of Boophilus microplus. The embryonic development of this arthropod is completed in 21 days. Cellularization of the blastoderm occurs on the 6th day and is rapidly followed by germ band extension and segmentation, whose first signs are visible on the 7th day. Cellularization is typically a maternal-driven process, carried out by molecular determinants deposited in the oocyte during oogenesis. On the other hand, segmentation is of zygotic nature, being the consequence of the synthesis of various components by the growing embryo. The enhancement in total B. microplus RNA was observed after cellularization, corroborating the replacement of maternal-driven processes by embryonic zygotic expression. An abrupt increase in oxygen consumption was observed from cellularization until the 8th day of development. The reduction in dry weight at the same period and the susceptibility of oxygen consumption to KCN suggest that the respiration process is activated during early embryonic development. A marked decrease in total lipid content occurred between the 5th and 7th days of development, suggesting this is the main energy source for cellularization. A major reduction in carbohydrate content occurred later, between the 7th and 9th days, and it could be assigned to the morphological segmentation of the embryo. Although the total amount of proteins remains unchanged from oviposition to hatching, a 15% reduction in vitellin (VT) content was observed before cellularization, up to the 4th day after egglaying. This observation was correlated to the synthesis of new proteins needed to support early embryo development. Additional 20% of VT was consumed thereafter, mainly at the end of embryogenesis, and in this case VT is probably used as energy source to the older embryo. Altogether, these data indicate different energy sources for maternal and zygotic driven processes.  相似文献   

Effect of imidocarb and levamisole on the experimental infection of BALB/c mice by Leishmania (Leishmania) amazonensis   总被引：1，自引：0，他引：1  

Rodrigues FH  Afonso-Cardoso SR  Gomes MA  Beletti ME  Rocha A  Guimarães AH  Candeloro I  de Souza MA 《Veterinary parasitology》2006,139(1-3):37-46

The adverse effects from using currently available drugs for the treatment of leishmaniasis have motivated the search for new therapeutical agents. The aim of this work was to evaluate the effect of imidocarb and levamisole on the treatment of BALB/c mice experimentally infected by Leishmania (Leishmania) amazonensis. BALB/c mice were infected with 10(6) promastigotes of L. (L.) amazonensis (IFLA/BR/67/PH8) and, starting on day 51, mice were treated subcutaneously with imidocarb (IMD, 34 mg/kg), imidocarb plus levamisole (IMD+LVS, 34 and 12 mg/kg, respectively), only levamisole (LVS, 12 mg/kg) or without treatment (control). Lesion size and swelling were weekly monitored for 10 weeks after the beginning of the treatment. On day 121 post-infection, serum levels of specific IgG from infected mice were evaluated, as well as histopathological and morphometric alterations in the footpad, lymph nodes and spleen of these animals. The data obtained in this study demonstrated that, when compared to controls, mice treated with IMD had lower levels of IgG anti-L. (L.) amazonensis (34.45%), smaller vacuolar area in macrophages (3.75%), lower number of megakaryocytes in spleen (63.19%) and lower parasite burden in the footpad (30.2%). Thus, the evaluated parameters suggest the use of imidocarb as a potential drug in the treatment of tegumentary leishmaniasis.  相似文献   

A Papaver somniferum 10-gene cluster for synthesis of the anticancer alkaloid noscapine     

Winzer T  Gazda V  He Z  Kaminski F  Kern M  Larson TR  Li Y  Meade F  Teodor R  Vaistij FE  Walker C  Bowser TA  Graham IA 《Science (New York, N.Y.)》2012,336(6089):1704-1708

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