Fine-scale foraging ecology and habitat use of sympatric green and hawksbill turtles in the Western Indian ocean.

Using stable isotope analysis of carbon and nitrogen of turtle tissues and putative prey items, we investigated the diet of immature green turtles and hawksbill turtles foraging in the lagoon of Aldabra Atoll, a relatively undisturbed atoll in the southern Seychelles. Aldabra offers a unique environment for understanding sea turtle ecology. Green turtles mostly consumed seagrass and brown algae while hawksbill turtles mainly consumed mangroves and invertebrates.

Marked differences in foraging area use and susceptibility to predation between two closely-related tropical seabirds.

Ecological theory predicts that closely-related species must occupy different niches to coexist. How marine top predators achieve this during breeding, when they often gather in large multi-species colonies and are constrained to central-place foraging, has been mostly studied in productive temperate and polar oceans with abundant resources, but less so in poorer, tropical waters. Here, we track the foraging movements of two closely-related sympatric seabirds-the white-tailed and red-tailed tropicbirds Phaethon lepturus and P.

First insights into coral recruit and juvenile abundances at remote Aldabra Atoll, Seychelles.

Coral recruitment and successive growth are essential for post-disturbance reef recovery. As coral recruit and juvenile abundances vary across locations and under different environmental regimes, their assessment at remote, undisturbed reefs improves our understanding of early life stage dynamics of corals. Here, we first explored changes in coral juvenile abundance across three locations (lagoon, seaward west and east) at remote Aldabra Atoll (Seychelles) between 2015 and 2019, which spanned the 2015/16 global coral bleaching event.

Early trajectories of benthic coral reef communities following the 2015/16 coral bleaching event at remote Aldabra Atoll, Seychelles.

Documenting post-bleaching trajectories of coral reef communities is crucial to understand their resilience to climate change. We investigated reef community changes following the 2015/16 bleaching event at Aldabra Atoll, where direct human impact is minimal. We combined benthic data collected pre- (2014) and post-bleaching (2016-2019) at 12 sites across three locations (lagoon, 2 m depth; seaward west and east, 5 and 15 m depth) with water temperature measurements.

The costs of removing the unsanctioned import of marine plastic litter to small island states.

Small island states receive unprecedented amounts of the world's plastic waste. In March 2019, we removed as much plastic litter as possible from Aldabra Atoll, a remote UNESCO World Heritage Site, and estimated the money and effort required to remove the remaining debris. We removed 25 tonnes at a cost of $224,537, which equates to around $10,000 per day of clean-up operations or $8,900 per tonne of litter.

The utilization of social networking sites, their perceived benefits and their potential for improving the study habits of nursing students in five countries.

Background: The abundance of easy and accessible information and the rapid development of social networking sites (SNSs) have proven that the world is small and within reach. The great implication of this interconnectivity is attributable to the change in the learning and sharing environment, which for the most part is something that classrooms are lacking. Considering the potential implications of SNSs in nursing education reveals the benefits of SNSs in allowing students to communicate and interact with a wider audience and beyond the classroom.

Cortical and trabecular bone are equally affected in rats with renal failure and secondary hyperparathyroidism.

Background: Changes in mineral metabolism and bone structure develop early in the course of chronic kidney disease and at end-stage are associated with increased risk of fragility fractures. The disruption of phosphorus homeostasis leads to secondary hyperparathyroidism, a common complication of chronic kidney disease. However, the molecular pathways by which high phosphorus influences bone metabolism in the early stages of the disease are not completely understood.

Inpatient citrate-based hemodialysis in pediatric patients.

Background: Citrate-based dialysate is an effective method of hemodialysis (HD) anticoagulation in adults. The objective of this study was to evaluate this therapy as an alternative to heparin anticoagulation in pediatric patients in the inpatient setting requiring HD.

Methods: We performed a prospective, non-randomized study of citrate-based dialysate HD treatments (N = 119) over a 9-month period in 18 pediatric patients (age range 0-18 years) admitted to hospital.

Growth-plate cartilage in chronic renal failure.

Bone growth occurs in the growth-plate cartilage located at the ends of long bones. Changes in the architecture, abnormalities in matrix organization, reduction in protein staining and RNA expression of factors involved in cell signaling have been described in the growth-plate cartilage of nephrectomized animals. These changes can lead to a smaller growth plate associated with decrease in chondrocyte proliferation, delayed hypertrophy, and prolonged initiation of mineralization and vascular invasion.

Bone growth during rapamycin therapy in young rats.

Background: Rapamycin is an effective immunosuppressant widely used to maintain the renal allograft in pediatric patients. Linear growth may be adversely affected in young children since rapamycin has potent anti-proliferative and anti-angiogenic properties.

Methods: Weanling three week old rats were given rapamycin at 2.

Mineral metabolism and bone abnormalities in children with chronic renal failure.

Abnormalities in mineral metabolism and changes in skeletal histology may contribute to growth impairment in children with chronic renal failure. Hyperphosphatemia, hypocalcemia, metabolic acidosis, alterations in vitamin D and IGF synthesis and parathyroid gland dysfunction play significant roles in the development of secondary hyperparathyroidism and subsequently, bone disease in renal failure. The recent KDIGO conference has made recommendations to consider this as a systemic disorder (chronic kidney disease-mineral bone disorder) and to standardize bone histomorphometry to include bone turnover, mineralization and volume (TMV).

Quantitative microcomputed tomography assessment of intratrabecular, intertrabecular, and cortical bone architecture in a rat model of severe renal osteodystrophy.

Objective: To determine the effects of renal osteodystrophy (ROD) on bone microarchitecture in growing rats.

Methods: A total of 24 rats underwent 5/6 nephrectomy (NX) and were fed a high-phosphorus diet to induce ROD; another 6 underwent sham NX. In vitro microcomputed tomography images (GEMS, London, Ontario, Canada) were obtained in the femoral metaphysis and midshaft.

Adynamic bone revisited: is there progress?

Adynamic or aplastic bone remains an important medical issue in children with chronic renal failure. To prevent the development of adynamic bone during treatment of secondary hyperparathyroidism, clinical recommendations have been made to maintain intact PTH levels at 2 to 4 times the normal values, avoid hypercalcemia, and keep serum phosphorus levels within age-appropriate limits in children with chronic renal failure. Less-calcemic vitamin D analogs and calcium-free and aluminum-free phosphate-binding agents should be used in children who can tolerate these agents.

Daily or intermittent calcitriol administration during growth hormone therapy in rats with renal failure and advanced secondary hyperparathyroidism.

Growth hormone (GH) improves growth in children with chronic renal failure. The response to GH may be affected by the degree of secondary hyperparathyroidism and concurrent treatment with vitamin D. Forty-six rats underwent 5/6 nephrectomy (Nx) and were given a high-phosphorus diet (Nx-Phos) to induce advanced secondary hyperparathyroidism and divided into the following groups: (1) Nx-Phos (n = 10) received saline, (2) GH at 10 IU/kg per d (Nx-Phos+GH; n = 9), (3) GH and daily calcitriol (D) at 50 ng/kg per d (Nx-Phos+GH+daily D; n = 8), (4) GH and intermittent D (three times weekly) at 350 ng/kg per wk (Nx-Phos+GH+int D; n = 9), and (5) intact-control (n = 10).

Chronotherapy of high-dose active Vitamin D(3): is evening dosing preferable?

Oral Vitamin D(3) is usually administered to children with chronic renal failure in the morning. Is there enough evidence that evening dosing is more beneficial with respect to suppression of parathyroid hormone and reduction of side effects such as hypercalcemia?

Bone elongation in rats with renal failure and mild or advanced secondary hyperparathyroidism.

Background: Impairment of growth in children with chronic renal failure may be due, in part to the insensitivity to the actions of growth hormone by insulin-like growth factor-I (IGF-I) because of accumulations of IGF binding proteins. There are a few studies describing the changes that occur in the growth plate in renal failure. None of these studies has simultaneously compared the modifications in the expression of selected markers of endochondral bone formation in renal failure with mild or advanced secondary hyperparathyroidism.

Growth hormone therapy in calcium-loaded rats with renal failure.

GH increases linear growth in children with chronic renal failure, but the response remains suboptimal in some patients. Some of the factors that may explain the poor response to GH include high doses of calcitriol and exogenous calcium loading to prevent hyperphosphatemia. High doses of exogenous calcium adversely affect chondrocyte proliferation and delay mineralization in the growth plate of rats with renal failure; bone histomorphometric changes in these animals are comparable to adynamic bone.

Secondary hyperparathyroidism in children with chronic renal failure: pathogenesis and treatment.

Despite advances in the management of patients with chronic renal failure, histologic features associated with secondary hyperparathyroidism remain the predominant skeletal findings; however, over the last decade the prevalence of adynamic bone has increased in both adult and pediatric patients with chronic renal failure. The management of children with secondary hyperparathyroidism and mild to moderate chronic renal failure should be started early, and should include correction of hypocalcemia and metabolic acidosis, maintenance of age-appropriate serum phosphorus levels, and institution of vitamin D therapy when serum intact parathyroid hormone (PTH) measurements are elevated to maintain the blood levels within normal limits; however, in children undergoing chronic dialysis therapy, the current recommendation is to maintain the serum intact PTH levels at least 2-4 times the upper limits of normal to prevent the development of low bone turnover disease. Serum calcium, phosphorus, alkaline phosphatase, and PTH levels should be monitored frequently, especially in infants and very young children.

Effects of thyroparathyroidectomy, exogenous calcium, and short-term calcitriol therapy on the growth plate in renal failure.

Several factors have been implicated in the development of adynamic bone, including the use of calcium-containing phosphate binding agents, aggressive calcitriol therapy, and parathyroidectomy. To evaluate the effects of these interventions on the growth plate, weanling rats underwent sham nephrectomy (Control, n = 10) and 5/6 nephrectomy (Nx). In the nephrectomized group, animals underwent (a) thyroparathyroidectomy (Nx-TPTX, n = 7), (b) received exogenous calcium (Nx-Calcium, n = 10), (c) received short-term calcitriol therapy (Nx-D, n = 10), or (d) nephrectomized control (Nx-Control, n = 10).

Growth hormone and the skeleton in pediatric renal allograft recipients.

Recombinant human growth hormone has been utilized to augment linear growth in pediatric renal allograft recipients. The skeletal changes that accompany growth hormone therapy have not been described in children. Thus, 23 stable prepubertal pediatric kidney recipients, aged 10 +/- 3 years, with a mean transplant time of 3.

Alterations in the growth plate cartilage of rats with renal failure receiving corticosteroid therapy.

Growth retardation is a complication often associated with corticosteroid therapy. Corticosteroids are frequently used in the treatment of children with chronic renal failure. To examine the effects of corticosteroids on the growth plate cartilage in renal failure, selected markers of chondrocyte function and phenotype were evaluated in the proximal tibia of subtotally nephrectomized rats treated with corticosteroid.