100 research outputs found
Evolution of retinoic acid receptors in chordates: insights from three lamprey species, Lampetra fluviatilis, Petromyzon marinus, and Lethenteron japonicum
International audienceBackground : Retinoic acid (RA) signaling controls many developmental processes in chordates, from early axis specification to late organogenesis. The functions of RA are chiefly mediated by a subfamily of nuclear hormone receptors, the retinoic acid receptors (RARs), that act as ligand-activated transcription factors. While RARs have been extensively studied in jawed vertebrates (that is, gnathostomes) and invertebrate chordates, very little is known about the repertoire and developmental roles of RARs in cyclostomes, which are extant jawless vertebrates. Here, we present the first extensive study of cyclostome RARs focusing on three different lamprey species: the European freshwater lamprey, Lampetra fluviatilis, the sea lamprey, Petromyzon marinus, and the Japanese lamprey, Lethenteron japonicum.Results : We identified four rar paralogs (rar1, rar2, rar3, and rar4) in each of the three lamprey species, and phylogenetic analyses indicate a complex evolutionary history of lamprey rar genes including the origin of rar1 and rar4 by lineage-specific duplication after the lamprey-hagfish split. We further assessed their expression patterns during embryonic development by in situ hybridization. The results show that lamprey rar genes are generally characterized by dynamic and highly specific expression domains in different embryonic tissues. In particular, lamprey rar genes exhibit combinatorial expression domains in the anterior central nervous system (CNS) and the pharyngeal region.Conclusions : Our results indicate that the genome of lampreys encodes at least four rar genes and suggest that the lamprey rar complement arose from vertebrate-specific whole genome duplications followed by a lamprey-specific duplication event. Moreover, we describe a combinatorial code of lamprey rar expression in both anterior CNS and pharynx resulting from dynamic and highly specific expression patterns during embryonic development. This ‘RAR code’ might function in regionalization and patterning of these two tissues by differentially modulating the expression of downstream effector genes during development
Contributions to the herpetofauna of the Angolan Okavango- Cuando-Zambezi river drainages. Part 2 : Lizards (Sauria), chelonians, and crocodiles
This work is the second report of the results obtained from a series of rapid biodiversity surveys
of the upper Cuito, Cubango, Cuando, Zambezi, and Kwanza River basins in Angola, which were conducted
between 2015 and 2019 in conjunction with the National Geographic Okavango Wilderness Project. The
herpetofauna of this region are poorly documented and the results of these surveys help to address the
knowledge gap regarding the conservation importance of this region. Here, an updated checklist is provided
for the current and historical records of lizards, chelonians, and crocodiles from the southeastern region of
Angola. A total of 369 new records were documented comprising 40 species, bringing the total number of
recognized lizard, chelonian, and crocodile species in this region to 58. These surveys documented four new
country records (i.e., Lygodactylus chobiensis, Agama armata, Pachydactylus wahlbergii, and Ichnotropis cf.
grandiceps) and increased the total number of reptile species known to occur in Angola (excluding snakes)
from approximately 157 to 161. Finally, updated distribution maps for the whole country are provided for all of
the species encountered in this study.Este trabalho é a segunda parte dos resultados de uma série de levantamentos rápidos de
biodiversidade realizados nas bacias dos rios Cuito, Cubango, Cuando, Zambeze e Kwanza em Angola, entre 2015
e 2019, em conjunto com o National Geographic Okavango Wilderness Project. A herpetofauna desta região está
pouco documentada, e os resultados destes levantamentos ajudarão a colmatar a lacuna de conhecimento sobre
a importância da sua conservação. Aqui apresentamos uma lista atualizada de registos históricos e recentes
dos lagartos, quelónios e crocodilos do sudeste de Angola. Ao todo, foram documentado 369 novos registros,
relativos a 40 espécies, elevando o número total de espécies desses três grupos na região para 58. Nestes
levantamentos foram registadas em Angola pela primeira vez quatro as espécies de lagartos (Lygodactylus
chobiensis, Agama armata, Pachydactylus wahlbergii, Ichnotropis cf. grandiceps), aumentando o número total
de espécies conhecidas de répteis (excluindo cobras) de Angola de 157 para 161. Por fim, apresentamos mapas
de ocorrência/distribuição atualizados das espécies encontradas neste estudo para todo o país.The Wild Bird Trust, which administers the National Geographic Okavango Wilderness Project.amphibian-reptile-conservation.orgam2023Zoology and Entomolog
Landscape science: a Russian geographical tradition
The Russian geographical tradition of landscape science (landshaftovedenie) is analyzed with particular reference to its initiator, Lev Semenovich Berg (1876-1950). The differences between prevailing Russian and Western concepts of landscape in geography are discussed, and their common origins in German geographical thought in the late nineteenth and early twentieth centuries are delineated. It is argued that the principal differences are accounted for by a number of factors, of which Russia's own distinctive tradition in environmental science deriving from the work of V. V. Dokuchaev (1846-1903), the activities of certain key individuals (such as Berg and C. O. Sauer), and the very different social and political circumstances in different parts of the world appear to be the most significant. At the same time it is noted that neither in Russia nor in the West have geographers succeeded in specifying an agreed and unproblematic understanding of landscape, or more broadly in promoting a common geographical conception of human-environment relationships. In light of such uncertainties, the latter part of the article argues for closer international links between the variant landscape traditions in geography as an important contribution to the quest for sustainability
Empoderamiento y feminismo comunitario en la conservación del maíz en México
Articulo científico para revista indizada.El objetivo es analizar, desde una perspectiva basada en el feminismo comunitario, el proceso de empoderamiento de las mujeres que conforman un grupo de ocho integrantes matlatzincas de la comunidad de San Francisco Oxtotilpan, México, a través de prácticas productivas, alimentarias y culturales en torno al maíz nativo. Los datos fueron recogidos durante 2014 y 2015 con técnicas etnográficas que incluyen: observación participante, historias de vida, grupos focales, entrevistas semiestructuradas y a profundidad. Son mujeres que muestran cinco dimensiones de poder (social, corporal, material, simbólico y cognitivo) que repercuten en la preservación del maíz nativo, al generar la masa crítica necesaria para incorporar a otras mujeres en acciones favorables para la soberanía alimentaria
Nebulized Recombinant Tissue Plasminogen Activator (rt-PA) for Acute COVID-19-Induced Respiratory Failure : An Exploratory Proof-of-Concept Trial
Acknowledgments We would like to extend our sincerest gratitude to all the colleagues and hospital staff who worked tirelessly throughout the pandemic and without whom this work would not have been possible. Firstly, we would like to thank our colleagues in the intensive care unit (ICU), in particular the matrons, Sean Carroll and Sinead Hanton, and research nurses, Filipe Helder and Amitaa Maharajh for their support, and bedside nurses who bore the responsibility of drug administration. We would also like to extend our thanks to ICU consultants who acted as professional legal consultees on behalf of critical care patients. Equally, we would like to thank colleagues within the respiratory team. Their expertise was instrumental to our role in treating patients on 8N and 8E wards. A special mention to lead Nurse Mary Emerson; we were grateful for her knowledge, support and for facilitating the training for the nebulizer and drug administration on the wards. We would like to thank Aarti Nandani and all the staff in the Royal Free clinical trials pharmacy for their immense support throughout the whole pandemic, especially considering their ever-increasing workload at the time. Thanks also to the HSL coagulation laboratory, the Trust R&D department and all the staff working to cover during a very challenging time. We are also very grateful to the Royal Free charity for funding this study. Finally, we would like to thank all the clinical nurses, physiotherapists, research data managers and healthcare professionals within the Haemophilia department (and wider hospital) for all their many efforts in supporting this study. This trial was overseen by an independent data monitoring committee, chaired by Najib Rahman, Director of the Oxford Respiratory Trials Unit, University of Oxford and comprises the following committee members: Mike Makris, Jonathan Silversides and Henry Watson. Funding Royal Free Charity Trust Fund 35 provided funding for this study. The study drug was provided by Boehringer Ingelheim (BI). BI had no role in the design, analysis, or interpretation of the results. They were given the opportunity to review the manuscript for medical and scientific accuracy since it relates to BI substances and intellectual property considerations.Peer reviewedPublisher PD
Microbial CO<sub>2</sub> fixation and sulfur cycling associated with low-temperature emissions at the Lilliput hydrothermal field, southern Mid-Atlantic Ridge (9°S)
Lilliput was discovered in 2005 as the southernmost known hydrothermal field along the Mid-Atlantic Ridge. It is exceptional in that it lacks high-temperature venting probably because of a thickened crust. The absence of thermophilic and hyperthermophilic prokaryotes in emissions supports the argument against the presence of a hot subsurface at Lilliput, as is typically suggested for diffuse emissions from areas of high-temperature venting. The high phylogenetic diversity and novelty of bacteria observed could be because of the low-temperature influence, the distinct location of the hydrothermal field or the Bathymodiolus assemblages covering the sites of discharge. The low-temperature fluids at the Lilliput are characterized by lowered pH and slightly elevated hydrogen (16 nM) and methane (∼2.6 μM) contents compared with ambient seawater. No typical hydrogen and methane oxidizing prokaryotes were detected. The higher diversity of reverse tricarboxylic acid genes and the form II RubisCO genes of the Calvin Benson-Bassham (CBB) cycle compared with the form I RubisCO genes of the CBB cycle suggests that the chemoautotrophic community is better adapted to low oxygen concentrations. Thiomicrospira spp. and Epsilonproteobacteria dominated the autotrophic community. Sulfide is the most abundant inorganic energy source (0.5 mM). Diverse bacteria were associated with sulfur cycling, including Gamma-, Delta- and Epsilonproteobacteria, with the latter being the most abundant bacteria according to fluorescence in situ hybridization. With members of various Candidate Divisions constituting for 25% of clone library sequences we suggest that their role in vent ecosystems might be more important than previously assumed and propose potential mechanisms they might be involved in at the Lilliput hydrothermal field
Heparin versus 0.9% sodium chloride intermittent flushing for prevention of occlusion in central venous catheters in adults
Background
Heparin intermittent flushing is a standard practice in the maintenance of patency in central venous catheters. However, we could find no systematic review examining its effectiveness and safety.
Objectives
To assess the effectiveness of intermittent flushing with heparin versus 0.9% sodium chloride (normal saline) solution in adults with central venous catheters in terms of prevention of occlusion and overall benefits versus harms.
Search methods
The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched December 2013) and the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 11). Searches were also carried out in MEDLINE, EMBASE, CINAHL and clinical trials databases (December 2013).
Selection criteria
Randomised controlled trials (RCTs) in adults 18 years of age and older with a central venous catheter (CVC) in which intermittent flushing with heparin (any dose with or without other drugs) was compared with 0.9% normal saline were included. No restriction on language was applied.
Data collection and analysis
Two review authors independently selected trials, assessed trial quality and extracted data. Trial authors were contacted to retrieve additional information, when necessary.
Main results
Six eligible studies with a total of 1433 participants were included. The heparin concentrations used in these studies were very different (10-5000 IU/mL), and follow-up varied from 20 days to 180 days. The overall risk of bias in the studies was low. The quality of the evidence ranged from very low to moderate for the main outcomes (occlusion of CVC, duration of catheter patency, CVC-related sepsis, mortality and haemorrhage at any site).
Combined findings from three trials in which the unit of analysis was the catheter suggest that heparin was associated with reduced CVC occlusion rates (risk ratio (RR) 0.53, 95% confidence interval (CI) 0.29 to 0.94). However, no clear evidence of a similar effect was found when the results of two studies in which the unit of analysis was the participant were combined (RR 0.21, 95% CI 0.03 to 1.70), nor when findings were derived from one study, which considered total line accesses (RR 1.08, 95% CI 0.84 to 1.40). Furthermore, results for other estimated effects were found to be imprecise and compatible with benefit and harm: catheter duration in days (mean difference (MD) 0.41, 95% CI -1.29 to 2.12), CVC-related thrombosis (RR 1.22, 95% CI 0.74 to 1.99), CVC-related sepsis (RR 1.02, 95% CI 0.34 to 3.03), mortality (RR 0.77, 95% CI 0.45 to 1.32) and haemorrhage at any site (RR 1.37, 95% CI 0.49 to 3.85).
Authors' conclusions
We found no conclusive evidence of important differences when heparin intermittent flushing was compared with 0.9% normal saline flushing for central venous catheter maintenance in terms of efficacy or safety. As heparin is more expensive than normal saline, our findings challenge its continued use in CVC flushing outside the context of clinical trials
A PP2A-B55 recognition signal controls substrate dephosphorylation kinetics during mitotic exit
PP2A-B55 is one of the major phosphatases regulating cell division. Despite its importance for temporal control during mitotic exit, how B55 substrates are recognised and differentially dephosphorylated is unclear. Using phosphoproteomics combined with kinetic modelling to extract B55-dependent rate constants, we have systematically identified B55 substrates and assigned their temporal order in mitotic exit. These substrates share a bipartite polybasic recognition determinant (BPR) flanking a Cdk1 phosphorylation-site. Experiments and modelling show that dephosphorylation rate is encoded into B55 substrates, including its inhibitor ENSA, by cooperative action of basic residues within the BPR. A complementary acidic surface on B55 decodes this signal, supporting a cooperative electrostatic mechanism for substrate selection. A further level of specificity is encoded into B55 substrates, since B55 displays selectivity for phosphothreonine. These simple biochemical properties, combined with feedback control of B55 activity by the phosphoserine-containing substrate/inhibitor ENSA can help explain the temporal sequence of events during exit from mitosis
On the typology and the worship status of sacred trees with a special reference to the Middle East
This article contains the reasons for the establishment of sacred trees in Israel based on a field study. It includes 97 interviews with Muslim and Druze informants. While Muslims (Arabs and Bedouins) consider sacred trees especially as an abode of righteous figures' (Wellis') souls or as having a connection to their graves, the Druze relate sacred trees especially to the events or deeds in the lives of prophets and religious leaders. A literary review shows the existence of 24 known reasons for the establishment of sacred trees worldwide, 11 of which are known in Israel one of these is reported here for the first time. We found different trends in monotheistic and polytheistic religions concerning their current worship of sacred trees
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
- …