Endocrine aspects of ovary growth and gestation in the Argentinian cockroach,Blaptica dubia (Dictyoptera,Blaberidae)

Titers of juvenile hormone (JH) III and free ecdysteroids were studied in the hemolymph of the ovoviviparous Argentinian cockroach, Blaptica dubia, related to fat body depletion and reproduction. Adult females were analyzed during the first (days 5–25) and second vitellogenic cycle (days 80–100) and during the periods of gestation. Body weight changes of adult females were closely related to ovarian growth, ootheca formation, ootheca deposition, and hatching of the nymphs. Biochemical analysis of the fat body revealed lipids as the main storage compounds, followed by glycogen, proteins, and free carbohydrates. Changes in the fat body weight and in the chemical constituents of the fat body correlated with the processes of vitellogenesis and gestation. Concentrations of JH and free ecdysteroids in the hemolymph were measured by high pressure liquid chromatography-mass spectrometry. JH III was the only JH homolog found. JH III titers were high during vitellogenesis as well as toward the end of the gestation period. Changes in the concentrations of ecdysone and 20-hydroxyecdysone were less clear. The results reveal JH III as the major gonadotropic hormone in adult females of B. dubia.     

口服脊髓灰质炎减毒活疫苗(人二倍体细胞)的稳定性研究

目的评价细胞工厂工艺连续生产的口服脊髓灰质炎减毒活疫苗(人二倍体细胞)的稳定性。方法疫苗在-20℃放置24个月,检测病毒滴度、外观、抗生素残留量、无菌性,及对病毒血清型进行鉴别;2~8℃放置12个月检测疫苗稳定性;室温放置7周、37℃放置7 d检测加速热稳定性并冻融的稳定性。结果该疫苗-20℃可贮存24个月以上,2~8℃有效期可延长至12个月,且冻融不会影响疫苗的稳定性。结论疫苗质量稳定,各项检测结果均符合《中华人民共和国药典》三部(2010版)及企业《口服脊髓灰质炎减毒活疫苗(人二倍体细胞)注册标准》。     

A mathematical model for the regulation of juvenile hormone titers

The titer of juvenile hormone (JH) is determined by three factors: its rate of synthesis, its rate of degradation, and the degree to which JH is protected from degradation by binding to a diversity of JH-binding proteins. All three of these factors vary throughout the life history of an insect and contribute to variation in the JH titer. The relative importance of each of these factors in determining variation in the JH titer is not known and can, presumably, differ in different life stages and different species. Here we develop a mathematical model for JH synthesis, degradation, and sequestration that allows us to describe quantitatively how each of these contribute to the titer of total JH and free JH in the hemolymph. Our model allows for a diversity of JH-binding proteins with different dissociation constants, and also for a number of different modes of degradation and inactivation. The model can be used to analyze whether data on synthesis and degradation are compatible with the observed titer data. We use the model to analyze two data sets, from Manduca and Gryllus, and show that in both cases, the known data on synthesis and degradation cannot account for the observed JH titers because the role of JH sequestration by binding proteins is greatly underestimated, and/or the in vivo rate of JH degradation is greatly overestimated. These analyses suggest that there is a critical need to develop a better understanding of the in vivo role of synthesis, sequestration and degradation in JH titer regulation.     

Ecology and management of northern pike in Wisconsin

Northern pike (pike) Esox lucius Linnaeus are broadly distributed across Wisconsin and provide an important sport fishery for anglers. Historical management has included use of angling regulations, stocking, and protection of critical habitat areas. Pike management is often a lower priority in comparison to more intensively managed species such as muskellunge Esox masquinongy Mitchell and walleye Sander vitreous. Pike provide angling opportunities year around, with higher catch rates and live release during open water, and higher harvest rates during winter. While length of pike caught during the two seasons is generally similar, there is some evidence that larger fish are caught during winter months. Results from minimum length limit changes implemented in 1995 have been equivocal and warrant further monitoring using standardized protocol to better determine effects on populations. If natural recruitment is not limited, pike populations can reach high densities and stunting can result. Loss of nearshore habitat has continued at an increased rate as more lake homes are built and shorelines graded, and altered with riprap, sand blankets, or sea walls. If natural recruitment is lacking, fry or fingerling stocking sustains or rehabilitates populations. Most pike stocking occurs in the southeastern portion of the state where habitat loss has been extensive. Stocking in other areas is largely to re-establish populations following a chemical reclamation or from winterkill. Future management needs to establish sampling protocols to ensure comparable data on both a temporal and a spatial scale. Long-term monitoring with these methods is essential to help determine effects of various factors (e.g., regulations, habitat loss) on populations. Guest editors: J. M. Farrell, C. Skov, M. Mingelbier, T. Margenau & J. E. Cooper International Pike Symposium: Merging Knowledge of Ecology, Biology, and Management for a Circumpolar Species     

Protective immunity of Nile tilapia against Ichthyophthirius multifiliis post-immunization with live theronts and sonicated trophonts

Two immunization trials were conducted to evaluate host protection of Nile tilapia, Oreochromis niloticus against Ichthyophthirius multifiliis (Ich). Immunizations were done with live theronts or sonicated trophonts by bath immersion and intraperitoneal (IP) injection. The immunized fish were challenged with theronts 21 days post-immunization in trial I and 180 days post-immunization in trial II. The serum anti-Ich antibody and cumulative mortalities of tilapia were determined after theront challenge. Serum anti-Ich antibody was significantly higher (P<0.05) in tilapia immunized with live theronts by immersion or IP injection or with sonicated trophonts administered by IP injection than tilapia immunized with sonicated trophonts by immersion, with bovine serum albumin by IP injection, or non-immunized controls. Host protection was acquired in fish immunized with live theronts by immersion or IP injection. Tilapia immunized with sonicated trophonts by IP injection were partially protected with a 57-77% survival in both trials. At 180 days post-immunization, serum antibody titers had declined in immunized fish yet they were still able to survive challenge. The protection appears not to be solely depending on serum antibody response against Ich.     

Micropropagation of Alocasia amazonica using semisolid and liquid cultures

An efficient, simple micropropagation method was developed for Alocasia amazonica using corms in semisolid and liquid cultures. Explants were cultured onto Murashige and Skoog (MS) medium (Murashige and Skoog, Physiol. Plant. 15:473–497, 1962) supplemented with different cytokinins (Benzyladenine [BA, 2.22–13.32 μM], kinetin [2.32–13.95 μM], Thidiazuron [TDZ, 0.45–4.54 μM]) and cytokinin in combination with auxins [naphthalene acetic acid (NAA, 0.54–5.37 μM)/indole acetic acid (IAA, 0.57–5.71 μM)/indole butyric acid (IBA, 0.49–4.9 μM)]. All supplementary-induced shoot proliferation and the optimal results was on the medium supplemented with 2.27 μM TDZ, which induced 5.1 shoots per explant. Among the different concentrations of sucrose (0–120 g l⁻¹) tested for shoot proliferation, 30 g l⁻¹ was found suitable for corm cultures of Alocasia amazonica. The optimal shoot proliferation and biomass values were with the plantlets grown at 30 μmol m⁻² s⁻¹ photosynthetic photon flux (PPF) and 25°C. Liquid cultures found suitable for shoot proliferation and biomass accumulation was compared to semisolid cultures. Comparative studies of bioreactor systems [continuous immersion (with or without net) and temporary immersion in liquid media using ebb and flood] revealed that shoot multiplication and growth were greatest with the raft bioreactor system. Plantlets (cormlets) from the bioreactor were hydroponically cultured for 30 days, and 100% of plants were acclimatized successfully. The simple efficient method of production of plantlets (cormlets) is useful for large-scale multiplication of this important ornamental plant. An erratum to this article can be found at     

Effects on vegetation composition of a modified forest harvesting and propagation method compared with clear‐cutting,scarification and planting

Question: How does the vegetation of boreal forests respond to harvesting and scarification? Location: 650 m a.s.l., central Sweden (61°38’ N). Methods: The response of boreal forest vegetation to cutting and scarification was studied in a field trial, which consisted of three treatments plus conventional harvesting as a control in a complete block design with four replicates. The cutting was done 14 years prior to vegetation inventory and scarification and planting were conducted the first or second years after cutting. Results: The species most abundant at higher cutting intensities were crustose lichens, Cladonia spp., Cladina arbuscula, Polytrichum spp. and pioneer mosses, the grass Deschampsia flexuosa, and the tree Betula pubescens, A few species had substantially lower abundance in treatments with higher cutting intensity, notably Hylocomium splendens and Vaccinium myrtillus. Scarification had a strong effect that was different from the one created by cutting. In scarification treatments, Polytrichum spp. were the only species with high abundance; most species had low abundance, i.e. Barbilophozia lycopodioides, Vaccinium vitis‐idaea, Pleurozium schreberi, Carex globularis, Empetrum nigrum, Cladina arbuscula, Sphagnum spp. Conclusions: Our results elaborate on the details of the well‐known effect of cutting on ground‐layer flora, and also give support for the profound and long‐lasting effect that soil scarification has on forest vegetation.     

琼脂扩散溶血试验测定嗜水气单胞菌HEC毒素的溶血价

建立琼脂扩散溶血试验用以测定嗜水气单胞菌HEC毒素的溶血价,同时与分光光度法及微量溶试验进行比较,结果表明琼脂扩散溶血试验所测溶血价滴度要高于前两种方法,而且重复性好,结果易于判定。     

A Positive Correlation between the Precursor Frequency of Cytotoxic Lymphocytes to Autologous Epstein-Barr Virus-Transformed B Cells and Antibody Titer Level against Epstein-Barr Virus-Associated Nuclear Antigen in Healthy Seropositive Individuals

A limiting dilution analysis was established to determine the precursor frequency (PF) of cytotoxic lymphocytes against autologous B cells transformed with the Epstein-Barr virus (EBV). This method was found to detect mainly self-restricted T-cell activity and little non-self-restricted cytotoxicity. The mean PF in 21 healthy EBV-seropositive persons was 1.4 × 10-³ (range: 0.03 × 10-³ to 8.7 × 10-³) for peripheral blood mononuclear cells, whereas 4 samples of mononuclear cells obtained from umbilical cord blood had PFs below 0.007 × 10-³. A positive correlation was observed between the PF and serum antibody titers against EBV-associated nuclear antigen among the seropositive persons.