Monthly day/night changes and seasonal daily rhythms of sexual steroids in Senegal sole (Solea senegalensis) under natural fluctuating or controlled environmental conditions

In this paper we attempted to investigate the existence of daily fluctuations on plasma sexual steroids (17beta-estradiol, E(2) and testosterone, T) in Senegal sole (Solea senegalensis) females. We described the monthly day/night concentrations and seasonal daily rhythms in animals reared under natural photo- and thermo-period. In addition, the influence of the natural annual fluctuation of the water temperature on the plasma concentration of these steroids was investigated, using one group of Senegal sole under a natural photoperiod, but with an attenuated thermal cycle (around 17-20 degrees C) for one year. Although no significant day/night differences were detected in monthly samplings, the existence of an annual rhythm of E(2) and T (p<0.01) with an acrophase in February was revealed by COSINOR analysis. Maximum values were reached in March for both steroids (6.1+/-1.7 ng mL(-1) at mid-dark, MD and 4.0+/-0.6 ng mL(-1) at mid-light, ML for E2 and 1.4+/-0.4 ng mL(-1) at MD and 0.8+/-0.1 ng mL(-1) at ML for T) in anticipation of the spawning season (May-June). As regards seasonal daily rhythms, the presence of daily oscillations was revealed. At the spring solstice (21st March) a daily rhythm was observed for both steroids (COSINOR, p<0.01), with an acrophase at 20:00 h (E(2)) and at 21:08 h (T). In summer, autumn and winter no daily rhythms were observed due to the low steroid levels at those seasons. When Senegal sole females were submitted to an attenuated annual thermal cycle, the steroid rhythm disappeared (there was no surge in spring, as in the control group) and these fish did not spawn, despite being subjected to natural photoperiod conditions. This result underlined the importance of the natural annual fluctuation of water temperature and photoperiod on the synchronization of the spawning season and on the onset of steroidogenesis.     

Human impacts decouple a fundamental ecological relationship—The positive association between host diversity and parasite diversity

Human impacts on ecosystems can decouple the fundamental ecological relationships that create patterns of diversity in free‐living species. Despite the abundance, ubiquity, and ecological importance of parasites, it is unknown whether the same decoupling effects occur for parasitic species. We investigated the influence of fishing on the relationship between host diversity and parasite diversity for parasites of coral reef fishes on three fished and three unfished islands in the central equatorial Pacific. Fishing was associated with a shallowing of the positive host‐diversity–parasite‐diversity relationship. This occurred primarily through negative impacts of fishing on the presence of complex life‐cycle parasites, which created a biologically impoverished parasite fauna of directly transmitted parasites resilient to changes in host biodiversity. Parasite diversity appears to be decoupled from host diversity by fishing impacts in this coral reef ecosystem, which suggests that such decoupling might also occur for parasites in other ecosystems affected by environmental change.     

Late stage dynamics of a successful feral goat eradication from the UNESCO World Heritage site of Aldabra Atoll,Seychelles

Feral goats Capra hircus, considered among the world’s most destructive invasive mammals, were introduced to Aldabra Atoll, a UNESCO World Heritage site in the Seychelles, before 1878. An eradication programme to remove goats from Aldabra was initiated in 1987, after severe ecological impacts were recorded. Eradication and control efforts continued intermittently for the next 20 years, and a final campaign was launched in 2007 using the Judas goat method. We present the methods, eradication dynamics, outcomes and financial costs of the final eradication campaign between 2007 and 2012. This effort was divided into three phases; (1) establishment of Judas goats and intensive hunting (4 months); (2) monitoring of Judas goats (4 years); and (3) Judas goat elimination and verification of success (8 months). In the focal 5-year period, 227 goats were culled (of 2297 across the entire 25-year period); 202 in phase 1, 21 in phase 2, and four remaining Judas goats in phase 3. The eradication was completed and confirmed successful in August 2012, following the use of multiple measures to confirm the absence of goats. The total cost of the eradication was US$ 185,105, an average of US$ 815/goat, or US$ 31/ha. The eradication, although ultimately successful, posed a unique combination of challenges. We discuss key lessons learned and put the project in context of other major island goat eradications. The financial details, context and lessons are expected to be of value to future practitioners.     

Über einen erblichen ß2-glykoprotein I-Mangel

Zusammenfassung Es wird über einen erblichen Mangel an ₂-Glykoprotein I berichtet. Dieses Protein, dessen Gehalt im Serum gesunder Blutspender nach quantitativen immunologischen Bestimmungen 20 mg/100 ml beträgt, fehlt bei 2 Mitgliedern der untersuchten Familien vollständig und ist im Serum von 5 weiteren Familienmitgliedern auf die Hälfte (7–11 mg/100 ml) verringert.

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Summary A congenital failure of ₂-glycoprotein is described. Whereas in the blood of normal donors 20 mg of this protein per 100 ml serum are proved by quantitative immunological methods, a total lack of ₂-glycoprotein was found with two members of the family in question and the serum of five others contains only half of the normal amount (7–11 mg per 100 ml).

     

The potential of DNA vaccination against tumor-associated antigens for antitumor therapy

Conventional treatment approaches for malignant tumors are highly invasive and sometimes have only a palliative effect. Therefore, there is an increasing demand to develop novel, more efficient treatment options. Increased efforts have been made to apply immunomodulatory strategies in antitumor treatment. In recent years, immunizations with naked plasmid DNA encoding tumor-associated antigens have revealed a number of advantages. By DNA vaccination, antigen-specific cellular as well as humoral immune responses can be generated. The induction of specific immune responses directed against antigens expressed in tumor cells and displayed e.g., by MHC class I complexes can inhibit tumor growth and lead to tumor rejection. The improvement of vaccine efficacy has become a critical goal in the development of DNA vaccination as antitumor therapy. The use of different DNA delivery techniques and coadministration of adjuvants including cytokine genes may influence the pattern of specific immune responses induced. This brief review describes recent developments to optimize DNA vaccination against tumor-associated antigens. The prerequisite for a successful antitumor vaccination is breaking tolerance to tumor-associated antigens, which represent "self-antigens." Currently, immunization with xenogeneic DNA to induce immune responses against self-molecules is under intensive investigation. Tumor cells can develop immune escape mechanisms by generation of antigen loss variants, therefore, it may be necessary that DNA vaccines contain more than one tumor antigen. Polyimmunization with a mixture of tumor-associated antigen genes may have a synergistic effect in tumor treatment. The identification of tumor antigens that may serve as targets for DNA immunization has proceeded rapidly. Preclinical studies in animal models are promising that DNA immunization is a potent strategy for mediating antitumor effects in vivo. Thus, DNA vaccines may offer a novel treatment for tumor patients. DNA vaccines may also be useful in the prevention of tumors with genetic predisposition. By DNA vaccination preventing infections, the development of viral-induced tumors may be avoided.