New Frontiers for Organismal Biology

Understanding how complex organisms function as integrated units that constantly interact with their environment is a long-standing challenge in biology. To address this challenge, organismal biology reveals general organizing principles of physiological systems and behavior—in particular, in complex multicellular animals. Organismal biology also focuses on the role of individual variability in the evolutionary maintenance of diversity. To broadly advance these frontiers, cross-compatibility of experimental designs, methodological approaches, and data interpretation pipelines represents a key prerequisite. It is now possible to rapidly and systematically analyze complete genomes to elucidate genetic variation associated with traits and conditions that define individuals, populations, and species. However, genetic variation alone does not explain the varied individual physiology and behavior of complex organisms. We propose that such emergent properties of complex organisms can best be explained through a renewed emphasis on the context and life-history dependence of individual phenotypes to complement genetic data.Organismic and Evolutionary Biolog

SN2017egm: A Helium-rich Superluminous Supernova with Multiple Bumps in the Light Curves

When discovered, SN~2017egm was the closest (redshift $z=0.03$) hydrogen-poor superluminous supernova (SLSN-I) and a rare case that exploded in a massive and metal-rich galaxy. Thus, it has since been extensively observed and studied. We report spectroscopic data showing strong emission at around He~I $\lambda$10,830 and four He~I absorption lines in the optical. Consequently, we classify SN~2017egm as a member of an emerging population of helium-rich SLSNe-I (i.e., SLSNe-Ib). We also present our late-time photometric observations. By combining them with archival data, we analyze high-cadence ultra-violet, optical, and near-infrared light curves spanning from early pre-peak ($\sim -20\,d$) to late phases ($\sim +300\,d$). We obtain its most complete bolometric light curve, in which multiple bumps are identified. None of the previously proposed models can satisfactorily explain all main light-curve features, while multiple interactions between the ejecta and circumstellar material (CSM) may explain the undulating features. The prominent infrared excess with a blackbody luminosity of $10^7$--$10^8\,L_{sun}$ detected in SN~2017egm could originate from the emission of either an echo of a pre-existing dust shell, or newly-formed dust, offering an additional piece of evidence supporting the ejecta-CSM interaction model. Moreover, our analysis of deep $Chandra$ observations yields the tightest-ever constraint on the X-ray emission of an SLSN-I, amounting to an X-ray-to-optical luminosity ratio $\lesssim 10^{-3}$ at late phases ($\sim100-200\,d$), which could help explore its close environment and central engine.Comment: 25 pages, 14 Figures, 4 Tables; accepted for publication in ApJ (Mar. 2023

Long-Term Conditioning to Elevated pCO2 and Warming Influences the Fatty and Amino Acid Composition of the Diatom Cylindrotheca fusiformis

The unabated rise in anthropogenic CO2 emissions is predicted to strongly influence the ocean's environment, increasing the mean sea-surface temperature by 4°C and causing a pH decline of 0.3 units by the year 2100. These changes are likely to affect the nutritional value of marine food sources since temperature and CO2 can influence the fatty (FA) and amino acid (AA) composition of marine primary producers. Here, essential amino (EA) and polyunsaturated fatty (PUFA) acids are of particular importance due to their nutritional value to higher trophic levels. In order to determine the interactive effects of CO2 and temperature on the nutritional quality of a primary producer, we analyzed the relative PUFA and EA composition of the diatom Cylindrotheca fusiformis cultured under a factorial matrix of 2 temperatures (14 and 19°C) and 3 partial pressures of CO2 (180, 380, 750 μatm) for >250 generations. Our results show a decay of ∼3% and ∼6% in PUFA and EA content in algae kept at a pCO2 of 750 μatm (high) compared to the 380 μatm (intermediate) CO2 treatments at 14°C. Cultures kept at 19°C displayed a ∼3% lower PUFA content under high compared to intermediate pCO2, while EA did not show differences between treatments. Algae grown at a pCO2 of 180 μatm (low) had a lower PUFA and AA content in relation to those at intermediate and high CO2 levels at 14°C, but there were no differences in EA at 19°C for any CO2 treatment. This study is the first to report adverse effects of warming and acidification on the EA of a primary producer, and corroborates previous observations of negative effects of these stressors on PUFA. Considering that only ∼20% of essential biomolecules such as PUFA (and possibly EA) are incorporated into new biomass at the next trophic level, thepotential impacts of adverse effects of ocean warming and acidification at the base of the food web may be amplified towards higher trophic levels, which rely on them as source of essential biomolecules

Environmental cues and constraints affecting the seasonality of dominant calanoid copepods in brackish, coastal waters: a case study of Acartia, Temora and Eurytemora species in the south-west Baltic

Information on physiological rates and tolerances helps one gain a cause-and-effect understanding of the role that some environmental (bottom–up) factors play in regulating the seasonality and productivity of key species. We combined the results of laboratory experiments on reproductive success and field time series data on adult abundance to explore factors controlling the seasonality of Acartia spp., Eurytemora affinis and Temora longicornis, key copepods of brackish, coastal and temperate environments. Patterns in laboratory and field data were discussed using a metabolic framework that included the effects of ‘controlling’, ‘masking’ and ‘directive’ environmental factors. Over a 5-year period, changes in adult abundance within two south-west Baltic field sites (Kiel Fjord Pier, 54°19′89N, 10°09′06E, 12–21 psu, and North/Baltic Sea Canal NOK, 54°20′45N, 9°57′02E, 4–10 psu) were evaluated with respect to changes in temperature, salinity, day length and chlorophyll a concentration. Acartia spp. dominated the copepod assemblage at both sites (up to 16,764 and 21,771 females m−3 at NOK and Pier) and was 4 to 10 times more abundant than E. affinis (to 2,939 m−3 at NOK) and T. longicornis (to 1,959 m−3 at Pier), respectively. Species-specific salinity tolerance explains differences in adult abundance between sampling sites whereas phenological differences among species are best explained by the influence of species-specific thermal windows and prey requirements supporting survival and egg production. Multiple intrinsic and extrinsic (environmental) factors influence the production of different egg types (normal and resting), regulate life-history strategies and influence match–mismatch dynamics

A Rare and Newly Recognized Kaposi Sarcoma Herpes Virus-Associated Disease

Introduction: Kaposi sarcoma herpesvirus (KSHV) is associated with Kaposi sarcoma, primary effusion lymphoma and multicentric Castleman disease (KSHV-MCD) in patients infected with human immunodeficiency virus (HIV). We present a case consistent with a newly recognized KSHV inflammatory cytokine syndrome (KICS), distinct from KSHV-MCD. Case Report: A 33-year-old African American male with a prior history of syphilis, HIV/AIDS on Triumeq and stage IV Kaposi sarcoma on Doxorubicin, presented with worsening fatigue, nausea, vomiting, myalgias, dyspnea and anasarca. His CD4 count remained at 33 cells/ul despite a low HIV-1 viral load. He was febrile and treated with multiple antibiotics, while extensive workups with cultures ruled out infectious causes. He had persistent hyponatremia, hypoalbuminemia, and then developed anemia and thrombocytopenia. Biopsy of his lymph node excluded KSHV-MCD. His significantly increased C-reactive protein and the absence of lymphadenopathy/splenomegaly on CT images led to the suspicion of KICS. KICS was further confirmed by high KSHV PCR (14855 copies/ml), massive elevation of cytokines IL-6 and IL-10. Even with aggressive immunoglobulin and supportive treatments, he died of multi-organ failure one month later. Discussion: Although both disorders exhibit signs of substantial inflammation, KICS is a different entity from KSHV-MCD. KICS is defined with no lymphadenopathy/splenomegaly and negative pathologic nodal changes in the setting of low CD4 count (/ul). Standard therapy is still under investigation due to its rarity and high mortality, whereas combination of Rituximab and Doxorubicin may lead to clinical remission. Early diagnosis and treatment initiation are crucial to improve survival of this under-recognized KSHV-associated disease.https://scholarlycommons.henryford.com/merf2019caserpt/1000/thumbnail.jp

Fidaxomicin versus vancomycin for infection with Clostridium difficile in Europe, Canada, and the USA: a double-blind, non-inferiority, randomised controlled trial.

Infection with Clostridium difficile is the primary infective cause of antibiotic-associated diarrhoea. We aimed to compare efficacy and safety of fidaxomicin and vancomycin to treat patients with C difficile infection in Europe, Canada, and the USA.Clinical TrialClinical Trial, Phase IIIComparative StudyJournal ArticleMulticenter StudyRandomized Controlled TrialResearch Support, Non-U.S. Gov'tOPT-80-004 Clinical Study Groupinfo:eu-repo/semantics/publishe