In order to assess the effect of dietary phosphorus (P) in reducing vertebral malformations and improving freshwater (FW) performance in triploid Atlantic salmon (Salmo salar), both triploid and ...diploid Atlantic salmon were fed three different dietary P inclusion levels (low: 4.9, medium: 7.7, and high: 9.7 g available P kg−1) from first feeding until smolt. Somatic and skeletal response was assessed at fry (~0.5 g), parr (~5 g) and smolt (~45 g) stages. Triploid parr initially grew faster on the high P diet, while groups fed low P resulted in a significantly higher weight at smolt. Image analysis of double stained Alcian blue and Alizarin red S fry revealed that low P fed triploid fish presented less well mineralised vertebrae, and significantly more malformed vertebrae in both parr and smolt stages following x-ray radiographic assessment. Triploid parr fed high and medium P had similar numbers of malformed vertebrae relative to their diploid counterparts but greater numbers than at smolt. Low P fed triploids had the highest prevalence of jaw and vertebral malformations as well as the highest number of deformed vertebrae in the central caudal vertebral region, which was more pronounced at parr than at smolt. Shorter vertebrae dorso-ventral lengths were observed throughout the spinal column (R1–R4) in parr fed low P and only in the caudal region (R3) at smolt. In parr, both ploidies showed reduced phosphate homeostasis protein fgf23 gene expression in vertebrae when fed low P diets, while triploids showed greater down-regulation of osteogenic factors (alp, opn and igf1r) between diets relative to diploids, suggesting possible greater active suppression of mineralisation and reduced osteogenic potential in triploids. No effects of diet or ploidy on gene expression were evident at smolt. Comparisons between development stages suggest early P supplementation in triploids is crucial for skeletal development. Ultimately, reducing vertebral deformities observed at smolt with higher P supplementation in triploids could contribute towards improving skeletal performance and welfare of the stocks in the marine phase.
•Feeding higher dietary P throughout freshwater significantly reduced occurrence of vertebral malformations in triploid Atlantic salmon.•Triploid growth was improved with higher dietary P within the fry to parr stages but reduced growth from parr to smolt.•Higher dietary P supplementation impeded diploid growth throughout freshwater.
ABSTRACT
This paper describes a ceramic assemblage from a Post‐Lapita site on Tetepare, a geologically distinct island on the periphery of the New Georgia group, Solomon Islands. Previous studies of ...ceramic assemblages in the region have found evidence of exotic sherds and patterns of pottery transfer indicating population mobility during a colonisation phase establishment of new communities in coastal lagoon settings. Here, a geochemical and petrographic comparison of the Tetepare assemblage to samples from similarly‐aged sites in nearby Roviana Lagoon and Kolombangara establishes a pattern of predominantly local production, with equivocal support for exotic transfers. This leads us to refine a model of increasing environmental knowledge, access and social connectivity, during the early phase dispersal of ceramic technologies into the region. We argue that our results clearly discriminate the Tetepare sherds from other assemblages and connect this observation to inferences about the variable character of regional interaction patterns. In addition, the environmental setting of the Tetepare site supplies further context for assessing the role of post‐depositional taphonomic processes and sea‐level change in structuring the visibility of intertidal pottery assemblages in the region.
Résumé
Cet article décrit un assemblage de céramique provenant d'un site post‐Lapita sur Tetepare, une île géologiquement distincte à la périphérie du groupe de Nouvelle‐Géorgie, aux Îles Salomon. Des études antérieures sur les assemblages de céramiques dans la région ont trouvé des preuves de schémas de transfert de tessons exotiques et de poterie indiquant la mobilité de la population pendant une phase de colonisation et l'établissement de nouvelles communautés dans les lagunes côtières. Ici, une comparaison géochimique et pétrographique de l'assemblage Tetepare avec des échantillons provenant de sites d'âge similaire dans la lagune voisine de Roviana et de Kolombangara établit un modèle de production principalement locale, avec un soutien équivoque pour les transferts exotiques. Cela nous amène à affiner un modèle d'augmentation des connaissances environnementales, de l'accès et de la connectivité sociale, au cours de la première phase de dispersion des technologies céramiques dans la région. Nous soutenons que nos résultats distinguent clairement les tessons Tetepare d'autres assemblages et relient cette observation à des inférences sur le caractère variable des modèles d'interaction régionaux. En outre, le cadre environnemental du site de Tetepare fournit un contexte supplémentaire pour évaluer le rôle des processus taphonomiques post‐sédimentaires et du changement du niveau de la mer dans la structuration de la visibilité des assemblages de poteries intertidales dans la région.
The need for accurate quantification of lead concentrations in urban centers around the world is turning attention towards rapid methods for contamination assessment. Portable X‐ray Fluorescence ...(pXRF) has been recognized as a more accessible alternative to traditional digestion methods. This study was conducted to produce measurement corrections for in‐situ pXRF measurements conducted on field soils under varying conditions of moisture, organic matter (OM) content, and particle size heterogeneity. Urban forest soils were analyzed for Pb under increasing soil moisture, OM, and coarse fraction contents with two different pXRF and the results were compared to reverse aqua regia digestions. While both instruments showed a strong correlation despite using different calibration methods, correction of pXRF data to digestion values improved accuracy but potentially underestimated Pb concentrations. We propose an empirical correction equation derived from the regression of variance between theoretical and observed concentrations to correct for moisture effects. OM and particle size heterogeneity did not produce a significant effect on Pb measurement and did not warrant correction. Our study confirms other work showing that pXRF provides an accurate and precise alternative to traditional digestion methods for Pb screening, provided that moisture is corrected.
Human ribosomal genes (rDNA) are located in nucleolar organizer regions (NORs) on the short arms of acrocentric chromosomes. Metaphase NORs that were transcriptionally active in the previous cell ...cycle appear as prominent chromosomal features termed secondary constrictions that are achromatic in chromosome banding and positive in silver staining. The architectural RNA polymerase I (pol I) transcription factor UBF binds extensively across rDNA throughout the cell cycle. To determine if UBF binding underpins NOR structure, we integrated large arrays of heterologous UBF-binding sequences at ectopic sites on human chromosomes. These arrays efficiently recruit UBF even to sites outside the nucleolus and, during metaphase, form novel silver stainable secondary constrictions, termed pseudo-NORs, morphologically similar to NORs. We demonstrate for the first time that in addition to UBF the other components of the pol I machinery are found associated with sequences across the entire human rDNA repeat. Remarkably, a significant fraction of these same pol I factors are sequestered by pseudo-NORs independent of both transcription and nucleoli. Because of the heterologous nature of the sequence employed, we infer that sequestration is mediated primarily by protein-protein interactions with UBF. These results suggest that extensive binding of UBF is responsible for formation and maintenance of the secondary constriction at active NORs. Furthermore, we propose that UBF mediates recruitment of the pol I machinery to nucleoli independently of promoter elements.
Objectives
There are few bioarcheological analyses of life experiences in colonial period Aotearoa New Zealand, despite this being a time of major adaptation and social change. In our study, early ...life histories are constructed from multi‐isotope and enamel peptide analysis of permanent first molars associated with Victorian era dental practices operating between AD 1881 and 1905 in Invercargill. Chemical analyses of the teeth provide insight into the childhood feeding practices, diet, and mobility of the people who had their teeth extracted.
Materials and Methods
Four permanent left mandibular first molars were analyzed from a cache of teeth discovered at the Leviathan Gift Depot site during excavations in 2019. The methods used were: (1) enamel peptide analysis to assess chromosomal sex; (2) bulk (δ13Ccarbonate) and incremental (δ13Ccollagen and δ15N) isotope analysis of dentin to assess childhood diet; and (3) strontium (87Sr/86Sr) and oxygen (δ18O) isotope analysis of enamel to assess childhood residency. Two modern permanent first molars from known individuals were analyzed as controls.
Results
The archaeological teeth were from three chromosomal males and one female. The protein and whole diets were predominately based on C3‐plants and domestic animal products (meat and milk). A breastfeeding signal was only identified in one historic male. All individuals likely had childhood residences in Aotearoa.
Discussion
Unlike most bioarcheological studies that rely on the remains of the dead, the teeth analysed in this study were extracted from living people. We suggest that the dental patients were likely second or third generation colonists to Aotearoa, with fairly similar childhood diets. They were potentially lower‐class individuals either living in, or passing through, the growing colonial center of Invercargill.
Multi‐method chemical analyses of Victorian dental extractions give insight into sex, childhood diet, and place of residence of patients.
Dental patients were likely born in Aotearoa, ate a “pākehā” (European) diet, and may have been lower‐class.
To provide guidance to clinicians about best practices, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the treatment and prevention of ...lightning injuries. These guidelines include a review of the epidemiology of lightning and recommendations for the prevention of lightning strikes, along with treatment recommendations organized by organ system. Recommendations are graded on the basis of the quality of supporting evidence according to criteria put forth by the American College of Chest Physicians. This is an updated version of the original WMS Practice Guidelines for Prevention and Treatment of Lightning Injuries published in Wilderness & Environmental Medicine 2012;23(3):260–269.
PDF
