Parnassus: Classical Journal (Volume 5, 2017)

Parnassus is an undergraduate journal published by the College of the Holy Cross in conjunction with the Classics Department. Parnassus\u27 mission is to share the passion of Holy Cross students for the ancient world. All pieces aim to be generally understandable, allowing the field to be more accessible to non-specialists in the community.https://crossworks.holycross.edu/parnassus/1004/thumbnail.jp

Increased Bone Volume and Correction of HYP Mouse Hypophosphatemia in the Klotho/HYP Mouse

Inactivating mutations of PHEX cause X-linked hypophosphatemia and result in increased circulating fibroblast growth factor 23 (FGF23). FGF23 action is dependent upon Klotho, which converts FGF receptor 1 into an FGF23-specific receptor. Disruption of Klotho results in a complex bone phenotype and hyperphosphatemia, the converse phenotype of X-linked hypophosphatemia. We examined effects of disrupting both Klotho and PHEX by creating a double-knockout (Klotho/HYP) mouse. The combined disruption corrected the hypophosphatemia in HYP mice, indicating that Klotho is epistatic to PHEX. FGF23 levels remained elevated in all groups except wild-type, indicating that Klotho is necessary for FGF23-dependent phosphaturic activity. 1,25-Dihydroxyvitamin D levels, reduced in HYP mice, were comparably elevated in Klotho and Klotho/HYP mice, demonstrating that Klotho is necessary for FGF23’s effect on vitamin D metabolism. Serum PTH levels were reduced in both Klotho and Klotho/HYP mice. Moreover, the Klotho null phenotype persisted in Klotho/HYP, maintaining the runty phenotype and decreased life span of Klotho null mice. Notably, microcomputed tomography analysis demonstrated greater trabecular bone volume fraction in Klotho/HYP mice than that in all other groups (Klotho/HYP, 56.2 ± 6.3%; Klotho, 32.5 ± 10.3%; HYP, 8.6 ± 7.7%; and wild type, 21.4 ± 3.4%; P < 0.004). Histomorphometric analysis confirmed the markedly increased trabecular bone density in Klotho/HYP mice and the well-established increase in osteoid volume in HYP mice. These observations suggest that with addition of Klotho loss of function, the overabundant osteoid typically produced in HYP mice (but fails to mineralize) is produced and mineralized in the double knockout, resulting in markedly enhanced trabecular bone density

Tracking data highlight the importance of human-induced mortality for large migratory birds at a flyway scale

Human-induced direct mortality affects huge numbers of birds each year, threatening hundreds of species worldwide. Tracking technologies can be an important tool to investigate temporal and spatial patterns of bird mortality as well as their drivers. We compiled 1704 mortality records from tracking studies across the African-Eurasian flyway for 45 species, including raptors, storks, and cranes, covering the period from 2003 to 2021. Our results show a higher frequency of human-induced causes of mortality than natural causes across taxonomic groups, geographical areas, and age classes. Moreover, we found that the frequency of human-induced mortality remained stable over the study period. From the human-induced mortality events with a known cause (n = 637), three main causes were identified: electrocution (40.5 %), illegal killing (21.7 %), and poisoning (16.3 %). Additionally, combined energy infrastructure-related mortality (i.e., electrocution, power line collision, and wind-farm collision) represented 49 % of all human-induced mortality events. Using a random forest model, the main predictors of human-induced mortality were found to be taxonomic group, geographic location (latitude and longitude), and human footprint index value at the location of mortality. Despite conservation efforts, human drivers of bird mortality in the African-Eurasian flyway do not appear to have declined over the last 15 years for the studied group of species. Results suggest that stronger conservation actions to address these threats across the flyway can reduce their impacts on species. In particular, projected future development of energy infrastructure is a representative example where application of planning, operation, and mitigation measures can enhance bird conservation.publishedVersio

Where are we now with European forest multi-taxon biodiversity and where can we head to?

International audienceForestry implementation significantly impacts forest biodiversity. Despite the promotion of Sustainable Forest Management (SFM) in Europe, sustainability assessments hardly account for direct biodiversity indicators. We aim to i) gather and map the existing information on forest multitaxon biodiversity associated with stand structure and management in Europe; ii) identify knowledge gaps for forest biodiversity research; and iii) discuss the research potential associated with multitaxon biodiversity data. We established a research network focused on multi-taxon biodiversity, stand structure and management data of European forests; and fitted species records, standing trees, lying deadwood, and sampling unit metadata from 34 local datasets. Suitable information was available for 3,591 sampling units, each surveyed for on average 4.6 taxonomic groups. Standing tree diameters, tree height deadwood and tree-related microhabitats were sampled in respectively 2,889; 2,356; 2,309 and 1,388 sampling units. Sampling unit metadata includes spatial coordinates, and compositional and management descriptors. Available data cover all the 14 European forest compositional categories but are unevenly distributed among them, with European beech forests being over-represented as compared to thermophilous and boreal forests. Overall, the available information has the potential to inform the development of conservation and SFM strategies for European forests by supporting: (i) methodological harmonization and coordinated monitoring; (ii) the definition and testing of SFM indicators and thresholds; (iii) datadriven assessment of the effects of environmental and management drivers on multi-taxon forest biological and functional diversity, (iv) multi-scale forest monitoring integrating in-situ and remotely sensed information