Tracking historical changes in the trophic ecology of the green turtle "Chelonia mydas" in the Hawaiian Islands

[eng] Hawaiian green turtles Chelonia mydas were heavily exploited for their fat, meat and eggs by the Polynesians in the pre-contact era and continued to be commercially exploited until 1978 when they were officially protected. These conservation measures allowed its population to rebound, although it is still considered threatened by the Endangered Species Act. Hawaiian green turtles have been the focus of intense research, but surprisingly, little is known about its trophic ecology and how it might have changed due to the anthropogenic impacts in the coastal ecosystems of the archipelago. This thesis aims to better understand the current habitat use and diet of green turtles in the Hawaiian Islands and track possible historical changes in their ecological niche. Underwater censuses in Oahu and the Kona coast revealed that green turtles had a strong preference for shallow, flat platforms covered with dense macroalgal pastures. Green turtle abundance was much lower in coral reefs, where they also had a modest contribution to the total biomass of herbivores, dominated by sea urchins and fishes. Not surprisingly, the stable isotope ratios of C, N and S in the epidermis of modern green turtles from east Oahu and the Kona coast confirmed a macroalgae- dominated diet, but seagrasses and mangroves had also relevant contributions to their diet in east Oahu, as well as fish in the Kona coast. Furthermore, the ontogenetic diet shift associated with the settlement of juvenile green turtles in neritic habitats is faster in eastern Oahu than in the Kona coast, perhaps because of the higher availability of macroalgae in the former. The stable isotope ratios of C, N and S in the squamosal and the ribs of the same green turtle individuals revealed similar patterns of geographic and ontogenetic variability, hence confirming that unprocessed bone samples are informative of diet prior to death. This is the base for retrospective analysis using museum specimens. However, mixing models using the trophic discrimination factor (TDF) derived experimentally for cortical bone yielded unreliable results when used on unprocessed bone samples, suggesting that trabecular bone has a different TDF value. This is relevant, because the skulls and carapaces preserved at museums are made of skeletal elements with a thick core or trabecular bone. Despite such limitation, the stable isotope ratios of C, N, and S in the skeletal elements of green turtles preserved in museums revealed minor changes in the isotopic niche of green turtles from east Oahu during the past 120 years. Nevertheless, the breadth of the isotopic niche decreased in the most recent years, indicating that ancient green turtles exhibited a broader diversity of individual foraging strategies, with a few individuals relying mostly on seagrasses and others consuming substantial amounts of animal matter. These trophic specialists are currently gone from eastern Oahu, where green turtles have converged on the use of the most abundant resource, red macroalgae, probably because of the homogenization and simplification of coastal habitats Nevertheless, results confirm that macroalgae were the staple diet for the majority of the green turtle population before the introduction of exotic red macroalgae and hence it is a trait characteristic of the Hawaiian population. To understand the relationship between diet and the morphology of the skull and the mandible, geometric and traditional morphometrics were used, comparing skulls and mandibles of populations relying mostly on seagrasses and populations relying mostly on macroalgae. Results showed that macroalgae consumers have longer and narrower skulls than seagrass consumers, the former is more suitable for selective browsing and suction feeding and the latter is better adapted for grazing and stronger bite force. The skull morphology of Hawaiian green turtles fits that general pattern but is different from that of the green turtles inhabiting the Mexican Pacific, although both are genetically related

Tracking historical changes in the trophic ecology of the green turtle "Chelonia mydas" in the Hawaiian Islands

Programa de Doctorat en Biodiversitat[eng] Hawaiian green turtles Chelonia mydas were heavily exploited for their fat, meat and eggs by the Polynesians in the pre-contact era and continued to be commercially exploited until 1978 when they were officially protected. These conservation measures allowed its population to rebound, although it is still considered threatened by the Endangered Species Act. Hawaiian green turtles have been the focus of intense research, but surprisingly, little is known about its trophic ecology and how it might have changed due to the anthropogenic impacts in the coastal ecosystems of the archipelago. This thesis aims to better understand the current habitat use and diet of green turtles in the Hawaiian Islands and track possible historical changes in their ecological niche. Underwater censuses in Oahu and the Kona coast revealed that green turtles had a strong preference for shallow, flat platforms covered with dense macroalgal pastures. Green turtle abundance was much lower in coral reefs, where they also had a modest contribution to the total biomass of herbivores, dominated by sea urchins and fishes. Not surprisingly, the stable isotope ratios of C, N and S in the epidermis of modern green turtles from east Oahu and the Kona coast confirmed a macroalgae- dominated diet, but seagrasses and mangroves had also relevant contributions to their diet in east Oahu, as well as fish in the Kona coast. Furthermore, the ontogenetic diet shift associated with the settlement of juvenile green turtles in neritic habitats is faster in eastern Oahu than in the Kona coast, perhaps because of the higher availability of macroalgae in the former. The stable isotope ratios of C, N and S in the squamosal and the ribs of the same green turtle individuals revealed similar patterns of geographic and ontogenetic variability, hence confirming that unprocessed bone samples are informative of diet prior to death. This is the base for retrospective analysis using museum specimens. However, mixing models using the trophic discrimination factor (TDF) derived experimentally for cortical bone yielded unreliable results when used on unprocessed bone samples, suggesting that trabecular bone has a different TDF value. This is relevant, because the skulls and carapaces preserved at museums are made of skeletal elements with a thick core or trabecular bone. Despite such limitation, the stable isotope ratios of C, N, and S in the skeletal elements of green turtles preserved in museums revealed minor changes in the isotopic niche of green turtles from east Oahu during the past 120 years. Nevertheless, the breadth of the isotopic niche decreased in the most recent years, indicating that ancient green turtles exhibited a broader diversity of individual foraging strategies, with a few individuals relying mostly on seagrasses and others consuming substantial amounts of animal matter. These trophic specialists are currently gone from eastern Oahu, where green turtles have converged on the use of the most abundant resource, red macroalgae, probably because of the homogenization and simplification of coastal habitats Nevertheless, results confirm that macroalgae were the staple diet for the majority of the green turtle population before the introduction of exotic red macroalgae and hence it is a trait characteristic of the Hawaiian population. To understand the relationship between diet and the morphology of the skull and the mandible, geometric and traditional morphometrics were used, comparing skulls and mandibles of populations relying mostly on seagrasses and populations relying mostly on macroalgae. Results showed that macroalgae consumers have longer and narrower skulls than seagrass consumers, the former is more suitable for selective browsing and suction feeding and the latter is better adapted for grazing and stronger bite force. The skull morphology of Hawaiian green turtles fits that general pattern but is different from that of the green turtles inhabiting the Mexican Pacific, although both are genetically related

Il Retail Banking in Italia

Indice: Definizione del business - Analisi del macroambiente - Analisi della domanda - Struttura dell'offert

What unrelated hematopoietic stem cell transplantation in thalassemia taught us about transplant immunogenetics

Although the past few decades have shown an improvement in the survival and complication-free survival rates in patients with beta-thalassemia major and gene therapy is already at an advanced stage of experimentation, hematopoietic stem cell transplantation (HSCT) continues to be the only effective and realistic approach to the cure of this chronic nonmalignant disease. Historically, human leukocyte antigen (HLA)-matched siblings have been the preferred source of donor cells owing to superior outcomes compared with HSCT from other sources. Nowadays, the availability of an international network of voluntary stem cell donor registries and cord blood banks has significantly increased the odds of finding a suitable HLA matched donor. Stringent immunogenetic criteria for donor selection have made it possible to achieve overall survival (OS) and thalassemia-free survival (TFS) rates comparable to those of sibling transplants. However, acute and chronic graft-versus-host disease (GVHD) remains the most important complication in unrelated HSCT in thalassemia, leading to significant rates of morbidity and mortality for a chronic non-malignant disease. A careful immunogenetic assessment of donors and recipients makes it possible to individualize appropriate strategies for its prevention and management. This review provides an overview of recent insights about immunogenetic factors involved in GVHD, which seem to have a potential role in the outcome of transplantation for thalassemia

Prophylactic and Preemptive Therapy with Dasatinib after Hematopoietic Stem Cell Transplantation for Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia

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Long-Lasting Protective Effect of Posaconazole Prophylaxis in Patients with Acute Myeloid Leukemia Receiving Allogeneic Hematopoietic Stem Cell Transplantation

Abstract Patients with acute myeloid leukemia (AML) during induction chemotherapy and those who receive allogeneic hematopoietic stem cell transplantation (HSCT) are at higher risk of invasive fungal infections (IFI). In the present study, we investigated whether the risk of IFI in AML patients receiving HSCT might be affected by the antifungal prophylaxis with posaconazole administered during the induction/salvage chemotherapy treatment. Between August 2001 and April 2015, 130 patients with AML received itraconazole/fluconazole (group A) and 99 received posaconazole (group B) as antifungal prophylaxis after induction/salvage chemotherapy at 7 Italian centers and all patients received fluconazole as antifungal prophylaxis after HSCT. The median duration of antifungal prophylaxis after induction/salvage chemotherapy was significantly longer for patients in group A than for those in group B (24 days versus 20 days, P  = .019). The 1-year cumulative incidence of proven/probable IFI after HSCT was 14% and 4% in group A and group B, respectively ( P  = .012). Fungal-free survival and overall survival at 1 year after HSCT were 66% and 70% in group A, and 75% and 77% in group B ( P  = .139 and P  = .302), respectively. Multivariate logistic analysis identified the use of alternative donors (matched unrelated donor: odds ratio [OR], 3.25; haploidentical/partially matched related donor: OR, 3.19), antifungal prophylaxis with itraconazole/fluconazole (OR, 3.82), and reduced-intensity conditioning (OR, 4.92) as independent risk factors for the development of IFI after HSCT. In summary, the present study suggests that the protective effects of posaconazole during induction/salvage chemotherapy for AML patients may have long-lasting benefits and eventually contribute to reduce the risk of IFI when patients undergo allogeneic HSCT

Prospective Assessment of Health-Related Quality of Life in Pediatric Patients with Beta-Thalassemia following Hematopoietic Stem Cell Transplantation

Although hematopoietic stem cell transplantation (HSCT) has been widely used to treat pediatric patients with beta-thalassemia major, evidence showing whether this treatment improves health-related quality of life (HRQoL) is lacking. We used child-self and parent-proxy reports to prospectively evaluate HRQoL in 28 children with beta-thalassemia from Middle Eastern countries who underwent allogeneic HSCT in Italy. The PedsQL 4.0 Generic Core Scales were administered to patients and their parents 1 month before and 3, 6, and 18 months after transplantation. Two-year overall survival, thalassemia-free survival, mortality, and rejection were 89.3%, 78.6%, 10.9% and 14.3%, respectively. The cumulative incidence of acute and chronic graft-versus-host disease (GVHD) was 36% and 18%, respectively. Physical functioning declined significantly from baseline to 3 months after HSCT (median PedsQL score, 81.3 vs 62.5; P = .02), but then increased significantly up to 18 months after HSCT (median score, 93.7; P = .04). Agreement between child-self and parent-proxy ratings was high. Chronic GVHD was the most significant factor associated with lower HRQoL scores over time ( P = .02). The child-self and parent-proxy reports showed improved HRQoL in the children with beta-thalassemia after HSCT. Overall, our study provides preliminary evidence-based data to further support clinical decision making in this area