199 research outputs found
Hatchery-produced sandfish (Holothuria scabra) show altered genetic diversity in New Caledonia
Facing an alarming continuing decline of wild sea cucumber resources,
management strategies were developed over the past three decades to sustainably
promote development, maintenance, or regeneration of wild sea cucumber
fisheries. In New Caledonia (South Pacific), dedicated management efforts via
restocking and sea ranching programs were implemented to cope with the
overharvesting of the sandfish Holothuria scabra and the recent loss of known
populations. In order to investigate genetic implications of a major H. scabra
restocking program, we assessed the genetic diversity and structure of wild
stocks and hatchery-produced sandfish and compared the genetic outcomes of
consecutive spawning and juvenile production events. For this, 1358 sandfish
collected at four sites along the northwestern coasts of New Caledonia, as well
as during five different restocking events in the Tiabet Bay, were genotyped
using nine polymorphic microsatellite markers. We found that wild H. scabra
populations from the northwestern coast of New Caledonia likely belonged to one
panmictic population with high level of gene flow observed along the study
scale. Further, this panmictic population displayed an effective size of
breeders large enough to ensure the feasibility of appropriate breeding
programs for restocking. In contrast, hatchery-produced samples did suffer from
an important reduction in the effective population size: the effective
population size were so small that genetic drift was detectable over one
generation, with the presence of inbred individuals, as well as more related
dyads than in wild populations. All these results suggest that dedicated
efforts in hatcheries are further needed to maintain genetic diversity of
hatchery-produced individuals in order to unbalance any negative impact during
this artificial selection
Managing small-scale fisheries confronted with socio-economic changes in New Caledonia (South Pacific)
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Evaluation of the performance of the governance of small-scale fisheries in the South
The importance of land infrastructure for supporting coastal fisheries has long been acknowledged; its role in remote and geographically challenged fishing communities in the Nordic Arctic has visibly impacted community structure and development. This paper explores the Red King Crab (RKC) fishery in Norway and the ways in which its management has been changing the socioeconomic landscape in Northern Finnmark since the beginning of commercial exploitation in the early 2000’s. The RKC in the Barents Sea is an intentionally introduced species that is viewed both as a nuisance and as a valuable economic resource. This induces ambivalent preferences among local stakeholders and decision-makers in Norway. Although the management challenge of invasive species with multiple roles is not new, there has been scant coverage of the underlying bioeconomic trade-offs. Low harvesting costs, uncertain ecosystem losses and ongoing infrastructure investment in onshore landing facilities all shape stakeholders' interests in Norway in favor of a long-term management of the fishery. Simultaneously the political willingness to support local coastal communities and livelihoods in northern Norway provides significant impetus for maintaining a long-term stock, particularly in Eastern Finnmark. The ongoing infrastructure investments favor regional stakeholders over more diffuse and less clearly identified interests in the ecosystem changes induced by the invasive crab
Enquête parasitologique et sérologique (Elisa-indirect) sur les trypanosomoses des bovins dans la zone de Sidéradougou, Burkina Faso
Une enquête parasitologique et sérologique sur les trypanosomoses des bovins a été réalisée dans le secteur nord de la zone de Sidéradougou (Burkina Faso), en novembre et décembre 1997. Partant d'un recensement terrestre exhaustif, un millier de bovins ont été examinés sur la base d'un échantillonnage stratifié aléatoire. L'âge et la race des animaux, la nature et la date du dernier traitement trypanocide ont été enregistrés. Les examens parasitologiques ont été effectués par la méthode du "buffy coat", la mesure de l'hématocrite a été recueillie et les tests Elisa-indirect ont été réalisés dans trois systèmes différents, avec sensibilisation des plaques par les antigènes solubles de Trypanosoma vivax, T. brucei ou T. congolense (type savane). La technique parasitologique a fourni 5,3 p. cent d'échantillons positifs, dominés par l'espèce T. congolense. Les examens sérologiques ont indiqué une séroprévalence de 81,7 p. cent (± 2,4 p. cent) les trois tests confondus et, sur la base des résultats chez les animaux âgés d'un an, une incidence annuelle moyenne de 52 p. cent (± 11p. cent). L'étude du score maximum de positivité aux trois tests a permis d'estimer les séroprévalences par espèce à 79 p. cent pour T. vivax, 3 p. cent pour T. brucei, et 28 p. cent pour T. congolense. L'analyse des données sérologiques et parasitologiques, selon la date du dernier traitement trypanocide indiqué par l'éleveur, montre que ces traitements ont peu d'effet sur le taux de portage des anticorps et des parasites, ce dernier est présumé assez proche de la séroprévalence observée. La méthode du "buffy coat" est insuffisamment sensible pour mesurer la prévalence des infections dans ce type de situation enzootique, mais, associée à la valeur de l'hématocrite, elle a permis d'estimer l'importance des cas de trypanosomose maladie à environ 15 p. cent. Les trypanosomoses bovines demeurent une préoccupation majeure de l'élevage dans la zone agropastorale de Sidéradougou. elles sévissent de manière enzootique avec une prédominance nette des infections par T. vivax, une prévalence et un impact clinique élevés de T. congolense. Les données générées par cette enquête seront intégrées dans un système d'information géographique (Sig) mis en place dans la zone pour l'évaluation du risque trypanosomien. (Résumé d'auteur
Growth, production and food preference of rohu Labeo rohita (H.)in monoculture and in polyculture with common carp Cyprinus carpio (L.) under fed and non-fed ponds
An experiment was carried out in 18 earthen ponds to investigate the effects of the addition of common carp Cyprinus carpio (L.) and artificial feed on natural food availability, food utilization and fish production in rohu Labeo rohita (Hamilton) ponds. Ponds were fertilized fortnightly with cow manure, urea and triple super phosphate. Rohu was stocked in all ponds at a density of 1.5 rohu m-2. All treatments were carried out in triplicate. Treatments were: rohu with and without formulated feed, rohu plus 0.5 common carp m-2 with and without feed, and rohu plus 1 common carp m-2 with and without feed. The time period between stocking and harvesting was four and half months. Stocking 0.5 common carp m-2 enhanced natural food availability in the pond, food utilization and rohu growth and production (P0.05) but increased zooplankton and benthic macroinvertebrate availability (P<0.001). Feed administration also enhanced growth of rohu and common carp (P<0.001). Rohu naturally ingests more phytoplankton than zooplankton but in the presence of formulated feed rohu shifted its natural food preference from phytoplankton to zooplankton. Common carp naturally ingests mainly zooplankton and benthic macroinvertebrate and small quantities of phytoplankton. However, when offered formulated feed, the latter becomes the preferred food item
Katwarn, NINA or FEMA? Multi-Method Study on Distribution, Use and Public Views on Crisis Apps
Crises, such as thunderstorms and an increasing number of (recognised) terroristic attacks in 2015, 2016, and 2017, do not only lead to extensive monetary damage, but also threaten human lives and influence citizens' perceptions of safety and security. In such situations, the population demands information about the damage and safe behaviour. Although some apps are available to provide this information, the number of users seems relatively low. Focussing on Germany, this study aims to research (1) the distribution of crisis apps in the population, (2) the kinds of crisis apps currently used, as well as (3) needed core functionalities of warning apps. This multi-method study analyses crisis apps by investigating their utilisation quantitatively in a snowball-based survey in Europe (n=1,034) and in a representative survey in Germany (n=1,369). Based on this, the German warning apps Katwarn and NINA and the US-American app FEMA are evaluated qualitatively (n=22). The results revealed requirements which informed the implementation of a warning app prototype. The prototype combines the identified advantages of the apps evaluated in the study, containing warnings and all-clear, recommendations for action, functions to contact friends and helpers. The contributions of this work are findings on the distribution of crisis apps in Europe and Germany (both 16%), the kinds of crisis apps used (mostly weather and warning apps), and empirically based requirements for warning apps which can be integrated in further developments of existing apps and a prototype for such an app
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Managing Small-Scale Fisheries Confronted With Socio-Economic Changes in New Caledonia (South Pacific)
On the rural Northwest coast of New Caledonia, the settlement of a world
class mining complex has initiated rapid socio-economic changes, linked
with a considerable demographic increase (+ 65% between 2007 and 2015)
and plentiful job opportunities. In 2007 and 2009, studies on fisheries and
commercialization of reef finfish and invertebrates were conducted to
assess how these changes could impact resource-use patterns. Results
showed that 1) economic, 2) social and 3) ecological changes were
expected. 1) The increase in demand (+70%) may strengthen the market for
marine products through the increase in local commercial fishing or
external supply that would diversify and lessen local fishing pressure. 2)
The lagoon uses were strongly linked to the social background of fishers.
Subsistence and recreational fishing practises were part of ways of life in
this rural area and may be modified by the ongoing local economic boom.
3) The overall fishing pressure (0.26 t/km²/year) was low. However, its
spatial distribution showed that some areas were close to overfishing.
Results suggested that the expected rise in commercial and recreational
fishing could lead to unsustainable exploitation levels in these zones. Given
the scope of potential changes, public authorities have to manage changing
lagoon uses to balance the indirect effects of economic development on the
local natural and social landscape. They will have to choose options that
would support the development of local fisheries, representing about
500,000 ¬ of sales a year, or maintain the present social organization and
ecological status of reefs.Keywords: Fish and Aquaculture Sectors Development, Small Scale Fisheries, Fisheries Economic
The European Butterfly Indicator for grassland species: 1990-2013
This report presents the fifth version of the European Grassland Butterfly Indicator, one of the EU biodiversity indicators of the European Environment Agency
Retreatment of hepatitis C non-responsive to Interferon. A placebo controlled randomized trial of Ribavirin monotherapy versus combination therapy with Ribavirin and Interferon in 121 patients in the Benelux [ISRCTN53821378]
BACKGROUND: Evidence based medicine depends on unbiased selection of completed randomized controlled trials. For completeness it is important to publish all trials. This report describes the first large randomised controlled trial where combination therapy was compared to placebo therapy and to ribavirin monotherapy, which has not been published untill now. METHODS: One hundred and twenty one patients with chronic hepatitis C and elevated transaminases who did not respond to previous treatment with standard interferon monotherapy, were included from 16 centers in Belgium, the Netherlands and Luxembourg between 1992 and 1996. Patient poor-response characteristics were: genotype 1 (69%), HCV RNA above 2 × 10(6 )copies/ml (55%) and cirrhosis (38%). Patients were randomized to 6 months combination therapy with interferon alpha-2b (3 MU tiw) and ribavirin (1000–1200 mg / day), 6 months ribavirin monotherapy (1000–1200 mg / day) or 6 months ribavirin placebo. The study was double blinded for the ribavirin / placebo component. One patient did not fit the entry criteria, and 3 did not start. All 117 patients who received at least one dose of treatment were included in the intention to treat analysis. RESULTS: At the end of treatment, HCV RNA was undetectable in 35% of patients on combination therapy and in none of the patients treated with ribavirin monotherapy or placebo. The sustained virological response rate at 6 months after therapy was 15% for patients treated with interferon and ribavirin. During the 6 months treatment period 13% of patients on interferon ribavirin combination therapy, 13% of patients on ribavirin monotherapy and 11% of patients on placebo withdrew due to side effects or noncompliance. At 24 weeks of treatment the mean Hb level was 85% of the baseline value, which means a mean decrease from 9.1 mmol/l to 7.8 mmol/l. The Hb levels at the end of treatment were not significantly different from patients treated with ribavirin monotherapy (p = 0.76). End of treatment WBC was significantly lower in patients treated with combination therapy, compared to ribavirin (p < 0.01) as well as for patients treated with ribavirin monotherapy compared to placebo (p < 0.01). DISCUSSION: This belated report on the only placebo controlled study of interferon ribavirin combination therapy in non responders to standard doses of interferon monotherapy documents the effectiveness, be it limited, of this approach as well as the dynamics of the effects on blood counts
Activation of MEK1 or MEK2 isoform is sufficient to fully transform intestinal epithelial cells and induce the formation of metastatic tumors
<p>Abstract</p> <p>Background</p> <p>The Ras-dependent ERK1/2 MAP kinase signaling pathway plays a central role in cell proliferation control and is frequently activated in human colorectal cancer. Small-molecule inhibitors of MEK1/MEK2 are therefore viewed as attractive drug candidates for the targeted therapy of this malignancy. However, the exact contribution of MEK1 and MEK2 to the pathogenesis of colorectal cancer remains to be established.</p> <p>Methods</p> <p>Wild type and constitutively active forms of MEK1 and MEK2 were ectopically expressed by retroviral gene transfer in the normal intestinal epithelial cell line IEC-6. We studied the impact of MEK1 and MEK2 activation on cellular morphology, cell proliferation, survival, migration, invasiveness, and tumorigenesis in mice. RNA interference was used to test the requirement for MEK1 and MEK2 function in maintaining the proliferation of human colorectal cancer cells.</p> <p>Results</p> <p>We found that expression of activated MEK1 or MEK2 is sufficient to morphologically transform intestinal epithelial cells, dysregulate cell proliferation and induce the formation of high-grade adenocarcinomas after orthotopic transplantation in mice. A large proportion of these intestinal tumors metastasize to the liver and lung. Mechanistically, activation of MEK1 or MEK2 up-regulates the expression of matrix metalloproteinases, promotes invasiveness and protects cells from undergoing anoikis. Importantly, we show that silencing of MEK2 expression completely suppresses the proliferation of human colon carcinoma cell lines, whereas inactivation of MEK1 has a much weaker effect.</p> <p>Conclusion</p> <p>MEK1 and MEK2 isoforms have similar transforming properties and are able to induce the formation of metastatic intestinal tumors in mice. Our results suggest that MEK2 plays a more important role than MEK1 in sustaining the proliferation of human colorectal cancer cells.</p
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