Rivers are dynamic ecosystems in which both human impacts and climate‐driven drying events are increasingly common. These anthropogenic and natural stressors interact to influence the biodiversity ...and functioning of river ecosystems. Disentangling ecological responses to these interacting stressors is necessary to guide management actions that support ecosystems adapting to global change.
We analysed the independent and interactive effects of human impacts and natural drying on aquatic invertebrate communities—a key biotic group used to assess the health of European freshwaters. We calculated biological response metrics representing communities from 406 rivers in eight European countries: taxonomic richness, functional richness and redundancy, and biomonitoring indices that indicate ecological status. We analysed metrics based on the whole community and a group of taxa with traits promoting resistance and/or resilience (‘high RR’) to drying. We also examined how responses vary across Europe in relation to climatic aridity.
Most community metrics decreased independently in response to impacts and drying. A richness‐independent biomonitoring index (the average score per taxon; ASPT) showed particular potential for use in biomonitoring, and should be considered alongside new metrics representing high RR diversity, to promote accurate assessment of ecological status.
High RR taxonomic richness responded only to impacts, not drying. However, these predictors explained little variance in richness and other high RR metrics, potentially due to low taxonomic richness. Metric responsiveness could thus be enhanced by developing region‐specific high RR groups comprising sufficient taxa with sufficiently variable impact sensitivities to indicate ecological status.
Synthesis and applications. Metrics are needed to assess the ecological status of dynamic river ecosystems—including those that sometimes dry—and thus to identify priority sites requiring action to tackle the causes of environmental degradation. Our results inform recommendations guiding the development of such metrics. We propose concurrent use of richness‐independent ‘average score per taxon’ indices and metrics that characterize the richness of resistant and resilient taxa. We observed interactions between aridity, impacts and drying, highlighting that these new metrics should be region specific, river type specific and adaptable, promoting their ability to inform management actions that protect biodiversity in river ecosystems responding to climate change.
Resum
Els rius són ecosistemes dinàmics subjectes a impactes humans i fenòmens naturals de sequera, cada vegada més comuns. Aquestes pertorbacions antròpiques i naturals interactuen i en determinen la biodiversitat i el funcionament dels ecosistemes fluvials. Entendre millor les respostes ecològiques a aquests dos tipus de pertorbacions és necessari per guiar accions de gestió de cara a l'adaptació al canvi global.
Hem analitzat els efectes independents i interactius dels impactes humans i de la sequera sobre les comunitats d'invertebrats aquàtics, un grup d'organismes clau per avaluar l'estat ecològic dels ecosistemes d'aigua dolça europeus. Hem calculat mètriques biològiques usant comunitats de 406 rius de vuit països europeus: riquesa taxonòmica, riquesa funcional i redundància, i dos índexs biològics usats en l'avaluació de l'estat ecològic. Hem analitzat mètriques basades en tota la comunitat, i un grup de tàxons amb trets característics que afavoreixen la resistència i/o la resistència (‘RR elevat’) a la sequera. També hem examinat com les respostes varien a tot Europa en relació amb l'aridesa del clima.
La majoria de les mètriques basades en tota la comunitat biològica van disminuir de manera independent als impactes i a la sequera. Un índex biològic que és independent de la riquesa taxonòmica (la puntuació mitjana per tàxon; ASPT) va mostrar una bona resposta per ser usat en biomonitoratge, i s'hauria de considerar, juntament amb les noves mètriques que representen una alta diversitat de RR, per promoure una avaluació precisa de l'estat ecològic.
L'alta riquesa taxonòmica de RR només va respondre als impactes, no a la sequera. No obstant això, aquests predictors van explicar poca variació en la riquesa i altres mètriques basades amb elevats valors RR, potencialment a causa de la baixa riquesa taxonòmica. Per tant, aquestes mètriques es podrien millorar mitjançant el desenvolupament de mètriques amb valors RR elevats específics de la regió, que incloguin suficients tàxons prou sensibles per indicar l'estat ecològic.
Síntesi i aplicacions. Es necessiten mètriques per avaluar l'estat ecològic dels ecosistemes fluvials dinàmics, inclosos els que de vegades s'assequen, i així identificar els llocs prioritaris on identificar i afrontar les causes de la degradació del medi. Els nostres resultats proporcionen recomanacions que guien el desenvolupament d'aquestes mètriques. Recomanem la consideració simultània d’índexs i mètriques ‘puntuació mitjana per taxó’ independents de la riquesa, que caracteritzen la riquesa de tàxons resistents i resistents. Les interaccions observades entre aridesa, impactes i la sequera ressalten que aquestes noves mètriques haurien de ser específiques per a la regió, específiques per tipus i adaptables, promovent la seva capacitat d'informar les accions de gestió que protegeixin la biodiversitat dels ecosistemes fluvials, i que responguin al canvi climàtic.
Metrics are needed to assess the ecological status of dynamic river ecosystems—including those that sometimes dry—and thus to identify priority sites requiring action to tackle the causes of environmental degradation. Our results inform recommendations guiding the development of such metrics. We propose concurrent use of richness‐independent ‘average score per taxon’ indices and metrics that characterize the richness of resistant and resilient taxa. We observed interactions between aridity, impacts and drying, highlighting that these new metrics should be region specific, river type specific and adaptable, promoting their ability to inform management actions that protect biodiversity in river ecosystems responding to climate change.
Cardiotrophin (CT‐1) signals through gp130 and the LIF receptor (LIFR) and plays a major role in cardiac, neurological, and liver biology. We report here that CT‐1 is also expressed within bone in ...osteoclasts and that CT‐1 is capable of increasing osteoblast activity and mineralization both in vitro and in vivo. Furthermore, CT‐1 stimulated CAAT/enhancer‐binding protein‐δ (C/EBPδ) expression and runt‐related transcription factor 2 (runx2) activation. In neonate CT‐1−/− mice, we detected low bone mass associated with reduced osteoblasts and many large osteoclasts, but increased cartilage remnants within the bone, suggesting impaired resorption. Cultured bone marrow (BM) from CT‐1−/− mice generated many oversized osteoclasts and mineralized poorly compared with wildtype BM. As the CT‐1−/− mice aged, the reduced osteoblast surface (ObS/BS) was no longer detected, but impaired bone resorption continued resulting in an osteopetrotic phenotype in adult bone. CT‐1 may now be classed as an essential osteoclast‐derived stimulus of both bone formation and resorption.
Synthetic genomics is an emerging field where large-scale DNA engineering is used to study and produce organisms of interest. Here we propose the marine diatom, Phaeodactylum tricornutum, as a ...candidate for a synthetic genome project and describe some of the strategies to bring this design, termed Pt-syn1.0, to life. This project is fueled by the emergence of a completed genome assembly, powerful methods for manipulating large-scale DNA, and effective DNA delivery methods. We propose that a recombination-deficient strain be created as a prerequisite to downstream genome manipulation to preserve any genetic modifications. In addition, the synthetic genome will be split between 50 chromosomes of approximately 500 kbp each to allow for easy construction and delivery. The establishment of a Pt-syn1.0 strain will lay the foundation for a streamlined engineering platform for P. tricornutum, alleviating many of the current constraints, and would drive diatom research and biotechnology into the next era.
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We present photometric and spectroscopic observations of the interacting transient SN 2009ip taken during the 2013 and 2014 observing seasons. We characterize the photometric evolution as a steady ...and smooth decline in all bands, with a decline rate that is slower than expected for a solely 56Co-powered supernova at late phases. No further outbursts or eruptions were seen over a two year period from 2012 December until 2014 December. SN 2009ip remains brighter than its historic minimum from pre-discovery images. Spectroscopically, SN 2009ip continues to be dominated by strong, narrow (≲2000 km s− 1) emission lines of H, He, Ca, and Fe. While we make tenuous detections of Fe ii λ7155 and O i λλ6300, 6364 lines at the end of 2013 June and the start of 2013 October, respectively, we see no strong broad nebular emission lines that could point to a core-collapse origin. In general, the lines appear relatively symmetric, with the exception of our final spectrum in 2014 May, when we observe the appearance of a redshifted shoulder of emission at +550 km s− 1. The lines are not blueshifted, and we see no significant near- or mid-infrared excess. From the spectroscopic and photometric evolution of SN 2009ip until 820 d after the start of the 2012a event, we still see no conclusive evidence for core-collapse, although whether any such signs could be masked by ongoing interaction is unclear.
The actin cytoskeleton remodels to enable diverse processes essential to immunity, such as cell adhesion, migration and phagocytosis. A panoply of actin-binding proteins regulate these rapid ...rearrangements to induce actin-based shape changes and to generate force. L-plastin (LPL) is a leukocyte-specific, actin-bundling protein that is regulated in part by phosphorylation of the Ser-5 residue. LPL deficiency in macrophages impairs motility, but not phagocytosis; we recently found that expression of LPL in which the S5 residue is converted to a non-phosphorylatable alanine (S5A-LPL) resulted in diminished phagocytosis, but unimpaired motility.
To provide mechanistic insight into these findings, we now compare the formation of podosomes (an adhesive structure) and phagosomes in alveolar macrophages derived from wild-type (WT), LPL-deficient, or S5A-LPL mice. Both podosomes and phagosomes require rapid remodeling of actin, and both are force-transmitting. Actin rearrangement, force generation, and signaling rely upon recruitment of many actin-binding proteins, including the adaptor protein vinculin and the integrin-associated kinase Pyk2. Prior work suggested that vinculin localization to podosomes was independent of LPL, while Pyk2 was displaced by LPL deficiency. We therefore chose to compare vinculin and Pyk2 co-localization with F-actin at sites of adhesion of phagocytosis in AMs derived from WT, S5A-LPL or LPL
mice, using Airyscan confocal microscopy.
As described previously, podosome stability was significantly disrupted by LPL deficiency. In contrast, LPL was dispensable for phagocytosis and was not recruited to phagosomes. Recruitment of vinculin to sites of phagocytosis was significantly enhanced in cells lacking LPL. Expression of S5A-LPL impeded phagocytosis, with reduced appearance of ingested bacteria-vinculin aggregates.
Our systematic analysis of the regulation of LPL during podosome vs. phagosome formation illuminates essential remodeling of actin during key immune processes.
Abstract
Introduction
Currently, operative reports are narrative and often handwritten, making interpretation difficult and potentially omitting key steps of the procedure. This study undertook a ...systematic review to determine the current availability of synoptic operative reporting and develop a synoptic operative record template for emergency laparotomy (EL).
Methods
A PROSPERO registered study from January 1st, 2012, to December 31st, 2022, was conducted using PubMed, Scopus, and Web of Science databases in February 2023. Keywords: emergency laparotomy AND operation notes OR operative notes OR documentation OR report OR pro forma OR narrative OR synoptic OR digital OR audio-visual. Studies on paediatric or pregnant patients, systematic reviews, meta-analyses, case reports, editorial comments, and letters were excluded. A synoptic operative record was designed to include key standards in the documentation, as suggested by the Colleges of Surgeons.
Results
The literature search yielded 4687 articles, and no relevant published articles were found. A detailed synoptic template was developed, which included 111 fields related to patient demographics, operative findings, interventions, and documentation of key variables associated with patient outcomes. 11 were text boxes, two were related to digital audio-visual uploads, and three facilitated the digital scoring/grading of findings.
Conclusion
This systematic review identified a limited number of publications reporting synoptic operative reporting, and none related to emergency laparotomy. This novel operative template provides a platform for clear documentation of the surgery performed during emergency laparotomy, potentially facilitating data analysis, resident training, and research, in turn leading to a better understanding of patient outcomes.
Many enzymes display non-Arrhenius behavior with curved Arrhenius plots in the absence of denaturation. There has been significant debate about the origin of this behavior and recently the role of ...the activation heat capacity (ΔC P ⧧) has been widely discussed. If enzyme-catalyzed reactions occur with appreciable negative values of ΔC P ⧧ (arising from narrowing of the conformational space along the reaction coordinate), then curved Arrhenius plots are a consequence. To investigate these phenomena in detail, we have collected high precision temperature-rate data over a wide temperature interval for a model glycosidase enzyme MalL, and a series of mutants that change the temperature-dependence of the enzyme-catalyzed rate. We use these data to test a range of models including macromolecular rate theory (MMRT) and an equilibrium model. In addition, we have performed extensive molecular dynamics (MD) simulations to characterize the conformational landscape traversed by MalL in the enzyme–substrate complex and an enzyme-transition state complex. We have crystallized the enzyme in a transition state-like conformation in the absence of a ligand and determined an X-ray crystal structure at very high resolution (1.10 Å). We show (using simulation) that this enzyme-transition state conformation has a more restricted conformational landscape than the wildtype enzyme. We coin the term “transition state-like conformation (TLC)” to apply to this state of the enzyme. Together, these results imply a cooperative conformational transition between an enzyme–substrate conformation (ES) and a transition-state-like conformation (TLC) that precedes the chemical step. We present a two-state model as an extension of MMRT (MMRT-2S) that describes the data along with a convenient approximation with linear temperature dependence of the activation heat capacity (MMRT-1L) that can be used where fewer data points are available. Our model rationalizes disparate behavior seen for MalL and previous results for a thermophilic alcohol dehydrogenase and is consistent with a raft of data for other enzymes. Our model can be used to characterize the conformational changes required for enzyme catalysis and provides insights into the role of cooperative conformational changes in transition state stabilization that are accompanied by changes in heat capacity for the system along the reaction coordinate. TLCs are likely to be of wide importance in understanding the temperature dependence of enzyme activity and other aspects of enzyme catalysis.
Bone strength is partially determined during cortical bone consolidation, a process comprising coalescence of peripheral trabecular bone and its progressive mineralisation. Mice with genetic deletion ...of suppressor of cytokine signalling 3 (Socs3), an inhibitor of STAT3 signalling, exhibit delayed cortical bone consolidation, indicated by high cortical porosity, low mineral content, and low bone strength. Since leptin receptor (LepR) is expressed in the osteoblast lineage and is suppressed by SOCS3, we evaluated whether LepR deletion in osteocytes would rectify the Dmp1cre.Socs3fl/fl bone defect. First, we tested LepR deletion in osteocytes by generating Dmp1cre.LepRfl/fl mice and detected no significant bone phenotype. We then generated Dmp1cre.Socs3fl/fl.LepRfl/fl mice and compared them to Dmp1cre.Socs3fl/fl controls. Between 6 and 12 weeks of age, both Dmp1cre.Socs3fl/fl.LepRfl/fl and control (Dmp1cre.Socs3fl/fl) mice showed an increasing proportion of more heavily mineralised bone, indicating some cortical consolidation with time. However, at 12 weeks of age, rather than resolving the phenotype, delayed consolidation was extended in female Dmp1cre.Socs3fl/fl.LepRfl/fl mice. This was indicated in both metaphysis and diaphysis by greater proportions of low-density bone, lower proportions of high-density bone, and greater cortical porosity than Dmp1cre.Socs3fl/fl controls. There was also no change in the proportion of osteocytes staining positive for phospho-STAT3, suggesting the effect of LepR deletion in Dmp1cre.Socs3fl/fl mice is STAT3-independent. This identifies a new role for leptin signalling in bone which opposes our original hypothesis. Although LepR in osteocytes has no irreplaceable physiological role in normal bone maturation, when STAT3 is hyperactive, LepR in Dmp1Cre-expressing cells supports cortical consolidation.
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