109 research outputs found
A New Paleozoic Symmoriiformes (Chondrichthyes) from the Late Carboniferous of Kansas (USA) and Cladistic Analysis of Early Chondrichthyans
BACKGROUND: The relationships of cartilaginous fishes are discussed in the light of well preserved three-dimensional Paleozoic specimens. There is no consensus to date on the interrelationship of Paleozoic chondrichthyans, although three main phylogenetic hypotheses exist in the current literature: 1. the Paleozoic shark-like chondrichthyans, such as the Symmoriiformes, are grouped along with the modern sharks (neoselachians) into a clade which is sister group of holocephalans; 2. the Symmoriiformes are related to holocephalans, whereas the other Paleozoic shark-like chondrichthyans are related to neoselachians; 3. many Paleozoic shark-like chondrichthyans, such as the Symmoriiformes, are stem chondrichthyans, whereas stem and crown holocephalans are sister group to the stem and crown neoselachians in a crown-chondrichthyan clade. This third hypothesis was proposed recently, based mainly on dental characters. METHODOLOGY/PRINCIPAL FINDINGS: On the basis of two well preserved chondrichthyan neurocrania from the Late Carboniferous of Kansas, USA, we describe here a new species of Symmoriiformes, Kawichthys moodiei gen. et sp. nov., which was investigated by means of computerized X-ray synchrotron microtomography. We present a new phylogenetic analysis based on neurocranial characters, which supports the third hypothesis and corroborates the hypothesis that crown-group chondrichthyans (Holocephali+Neoselachii) form a tightly-knit group within the chondrichthyan total group, by providing additional, non dental characters. CONCLUSIONS/SIGNIFICANCE: Our results highlight the importance of new well preserved Paleozoic fossils and new techniques of observation, and suggest that a new look at the synapomorphies of the crown-group chondrichthyans would be worthwhile in terms of understanding the adaptive significance of phylogenetically important characters
Contribution of SAR Radar Images for the Cartography: Case of Mangrove and Post Eruptive Regions
A Congolese community-based health program for survivors of sexual violence
Many survivors of gender based violence (GBV) in the Democratic Republic of Congo (DRC) report barriers to access health services including, distance, cost, lack of trained providers and fear of stigma. In 2004, Foundation RamaLevina (FORAL), a Congolese health and social non-governmental organization, started a mobile health program for vulnerable women and men to address the barriers to access identified by GBV survivors and their families in rural South Kivu province, Eastern DRC. FORAL conducted a case study of the implementation of this program between July 2010-June 2011 in 6 rural villages. The case study engaged FORAL staff, partner health care providers, community leaders and survivors in developing and implementing a revised strategy with the goal of improving and sustaining health services. The case study focused on: (1) Expansion of mobile clinic services and visit schedule; (2) Clinical monitoring and evaluation system; and (3) Recognition, documentation and brief psychosocial support for symptoms suggestive of anxiety, depression and PTSD. During this period, FORAL treated 772 women of which 85% reported being survivors of sexual violence. Almost half of the women (45%) reported never receiving health services after the last sexual assault. The majority of survivors reported symptoms consistent with STI. Male partner adherence to STI treatment was low (41%). The case study demonstrated areas of strengths in FORAL’s program, including improved access to health care by survivors and their male partner, enhanced quality of health education and facilitated regular monitoring, follow-up care and referrals. In addition, three critical areas were identified by FORAL that needed further development: provision of health services to young, unmarried women in a way that reduces possibility of future stigma, engaging male partners in health education and clinical care and strengthening linkages for referral of survivors and their partners to psychosocial support and mental health services. FORAL’s model of offering health education to all community members, partnering with local providers to leverage resources and their principal of avoiding labeling the clinic as one for survivors will help women and their families in the DRC and other conflict settings to comfortably and safely access needed health care services
Neurocranial development of the coelacanth and the evolution of the sarcopterygian head
The neurocranium of sarcopterygian fishes was originally divided into an anterior (ethmosphenoid) and posterior (otoccipital) portion by an intracranial joint, and underwent major changes in its overall geometry before fusing into a single unit in lungfishes and early tetrapods. Although the pattern of these changes is well-documented, the developmental mechanisms that underpin variation in the form of the neurocranium and its associated soft tissues during the evolution of sarcopterygian fishes remain poorly understood. The coelacanth Latimeria is the only known living vertebrate that retains an intracranial joint. Despite its importance for understanding neurocranial evolution, the development of the neurocranium of this ovoviviparous fish remains unknown. Here we investigate the ontogeny of the neurocranium and brain in Latimeria chalumnae using conventional and synchrotron X-ray microcomputed tomography as well as magnetic resonance imaging, performed on an extensive growth series for this species. We describe the neurocranium at the earliest developmental stage known for Latimeria, as well as the major changes that the neurocranium undergoes during ontogeny. Changes in the neurocranium are associated with an extreme reduction in the relative size of the brain along with an enlargement of the notochord. The development of the notochord appears to have a major effect on the surrounding cranial components, and might underpin the formation of the intracranial joint. Our results shed light on the interplay between the neurocranium and its adjacent soft tissues during development in Latimeria, and provide insights into the developmental mechanisms that are likely to have underpinned the evolution of neurocranial diversity in sarcopterygian fishes
Multi-Channel Auto-Calibration for the Atmospheric Imaging Assembly using Machine Learning
Solar activity plays a quintessential role in influencing the interplanetary
medium and space-weather around the Earth. Remote sensing instruments onboard
heliophysics space missions provide a pool of information about the Sun's
activity via the measurement of its magnetic field and the emission of light
from the multi-layered, multi-thermal, and dynamic solar atmosphere. Extreme UV
(EUV) wavelength observations from space help in understanding the subtleties
of the outer layers of the Sun, namely the chromosphere and the corona.
Unfortunately, such instruments, like the Atmospheric Imaging Assembly (AIA)
onboard NASA's Solar Dynamics Observatory (SDO), suffer from time-dependent
degradation, reducing their sensitivity. Current state-of-the-art calibration
techniques rely on periodic sounding rockets, which can be infrequent and
rather unfeasible for deep-space missions. We present an alternative
calibration approach based on convolutional neural networks (CNNs). We use
SDO-AIA data for our analysis. Our results show that CNN-based models could
comprehensively reproduce the sounding rocket experiments' outcomes within a
reasonable degree of accuracy, indicating that it performs equally well
compared with the current techniques. Furthermore, a comparison with a standard
"astronomer's technique" baseline model reveals that the CNN approach
significantly outperforms this baseline. Our approach establishes the framework
for a novel technique to calibrate EUV instruments and advance our
understanding of the cross-channel relation between different EUV channels.Comment: 12 pages, 7 figures, 8 tables. This is a pre-print of an article
submitted and accepted by A&A Journa
Apport Nutritionnel Des Aliments Consommés Par Les Adolescents De L’école Congolaise De Basket Ball « Gametime » De Brazzaville
Notre étude avait pour objectif d’évaluer l’énergie apportée par les aliments consommés par les adolescents de l’école congolaise de Basket-ball (GAMETIME) pendant la période d’entrainement et comparer ces apports aux normes recommandées par les nutritionnistes. Une enquête de consommation alimentaire a été menée auprès de 10 joueurs dont l’âge moyen était de 15,03 ± 3,65 ans. Le poids moyen était de 41,57 ± 5,18kg, tandis que la taille moyenne des sujets était de 1,69 ± 0,09m. La méthode utilisée était celle de rappel de 24 heures. Les résultats ont indiqué que 70% des sujets prennent 2 repas par jour et ces repas sont constitués de déjeuner (60%) et du diner (30%). Toutefois, l’apport nutritionnel trouvé était de 3717,12 kilocalories. Tandis que la dépense énergétique était estimée à 2827,29 ±128,87 kilocalories. Par ailleurs, les pourcentages des apports étaient respectivement de 68,95 % en glucides (˃ à 60 %), de 19,52 % en lipides (< à 30 %) et de 11,53 % en protides (< à 15 %). Cependant, les apports énergétiques trouvés étaient supérieurs aux dépenses énergétiques, soit une différence de 889,83 ± 3,38 kilocalories a été constatée. La balance énergétique était plus dominée par des apports que des dépenses. Ces apports répondaient superficiellement aux normes recommandées. En conclusion, l’apport en macronutriment a montré des pourcentages incohérents par rapport aux normes recommandés. L’alimentation des basketteurs adolescents congolais était non seulement hyper glucidique mais malheureusement hypo lipidique et hypo protéique. Ces macronutriments déséquilibrés sont considérés comme facteurs limitants de performance.
Our study aimed to evaluate the energy provided by the foods consumed by adolescents from the Congolese basketball school (GAMETIME) during the training period and to compare these contributions to the standards recommended by nutritionists. A food consumption survey was conducted among 10 players whose average age was 15.03 ± 3.65 years. The average weight was 41.57 ± 5.18 kg, while the average height of the subjects was 1.69 ± 0.09 m. The method used was the 24 hour callback. The results indicated that 70% of the subjects took 2 meals per day and these meals consisted of lunch (60%) and dinner (30%). However, the nutrient intake found was 3717.12 kilocalories. While the energy expenditure was estimated at 2827.29 ± 128.87 kilocalories. In addition, the percentages of intakes were respectively 68.95% in carbohydrates (˃ to 60%), 19.52% in lipids (<30%) and 11.53% in proteins (<15%). However, the energy intake found was greater than the energy expenditure, a difference of 889.83 ± 3.38 kilocalories was observed. The energy balance was more dominated by intakes than expenditures. These contributions superficially met the recommended standards. In conclusion, the macronutrient intake showed inconsisten percentages compared to the recommended standards. The diet of Congolese adolescent basketball players was not only high in carbohydrates but unfortunately low in fat and low in protein. These imbalanced macronutrients are considered as performance limiting factors
Diverse New Microvertebrate Assemblage from the Upper Triassic Cumnock Formation, Sanford Subbasin, North Carolina, USA
The Moncure microvertebrate locality in the Cumnock Formation, Sanford sub-basin, North Carolina, dramatically increases the known Late Triassic age vertebrate assemblage from the Deep River Basin. The 50,000 recovered microvertebrate fossils include osteichthyans, amphibians, and numerous lepidosauromorph, archosauriform, and synapsid amniotes. Actinopterygian fossils consist of thousands of scales, teeth, skull, and lower jaw fragments, principally of redfieldiids and semionotids. Non-tetrapod sarcopterygians include the dipnoan Arganodus sp., the first record of lungfish in the Newark Supergroup. Temnospondyls are comparatively rare but the preserved centra, teeth, and skull fragments probably represent small (juvenile) metoposaurids. Two fragmentary teeth are assigned to the unusual reptile Colognathus obscurus (Case). Poorly preserved but intriguing records include acrodont and pleurodont jaw fragments tentatively assigned to lepidosaurs. Among the archosauriform teeth is a taxon distinct from R. callenderi that we assign to Revueltosaurus olseni new combination, a morphotype best assigned to cf. Galtonia, the first Newark Supergroup record of Crosbysaurus sp., and several other archosauriform tooth morphotypes, as well as grooved teeth assigned to the recently named species Uatchitodon schneideri. Synapsids represented by molariform teeth include both "traversodontids" assigned to aff. Boreogomphodon and the "dromatheriid" Microconodon. These records are biogeographically important, with many new records for the Cumnock Formation and/or the Newark Supergroup. In particular, Colognathus, Crosbysaurus, and Uatchitodon are known from basins of Adamanian age in the southwestern U.S.A. These new records include microvertebrate taxa more typical of non-Newark basins (abundant archosauriforms, temnospondyls, lungfish) as well as more typical Newark osteichthyans and synapsid-rich faunal elements
Erratum to: the buccohypophyseal canal is an ancestral vertebrate trait maintained by modulation in sonic hedgehog signaling
Adjunctive rifampicin for Staphylococcus aureus bacteraemia (ARREST): a multicentre, randomised, double-blind, placebo-controlled trial.
BACKGROUND: Staphylococcus aureus bacteraemia is a common cause of severe community-acquired and hospital-acquired infection worldwide. We tested the hypothesis that adjunctive rifampicin would reduce bacteriologically confirmed treatment failure or disease recurrence, or death, by enhancing early S aureus killing, sterilising infected foci and blood faster, and reducing risks of dissemination and metastatic infection. METHODS: In this multicentre, randomised, double-blind, placebo-controlled trial, adults (≥18 years) with S aureus bacteraemia who had received ≤96 h of active antibiotic therapy were recruited from 29 UK hospitals. Patients were randomly assigned (1:1) via a computer-generated sequential randomisation list to receive 2 weeks of adjunctive rifampicin (600 mg or 900 mg per day according to weight, oral or intravenous) versus identical placebo, together with standard antibiotic therapy. Randomisation was stratified by centre. Patients, investigators, and those caring for the patients were masked to group allocation. The primary outcome was time to bacteriologically confirmed treatment failure or disease recurrence, or death (all-cause), from randomisation to 12 weeks, adjudicated by an independent review committee masked to the treatment. Analysis was intention to treat. This trial was registered, number ISRCTN37666216, and is closed to new participants. FINDINGS: Between Dec 10, 2012, and Oct 25, 2016, 758 eligible participants were randomly assigned: 370 to rifampicin and 388 to placebo. 485 (64%) participants had community-acquired S aureus infections, and 132 (17%) had nosocomial S aureus infections. 47 (6%) had meticillin-resistant infections. 301 (40%) participants had an initial deep infection focus. Standard antibiotics were given for 29 (IQR 18-45) days; 619 (82%) participants received flucloxacillin. By week 12, 62 (17%) of participants who received rifampicin versus 71 (18%) who received placebo experienced treatment failure or disease recurrence, or died (absolute risk difference -1·4%, 95% CI -7·0 to 4·3; hazard ratio 0·96, 0·68-1·35, p=0·81). From randomisation to 12 weeks, no evidence of differences in serious (p=0·17) or grade 3-4 (p=0·36) adverse events were observed; however, 63 (17%) participants in the rifampicin group versus 39 (10%) in the placebo group had antibiotic or trial drug-modifying adverse events (p=0·004), and 24 (6%) versus six (2%) had drug interactions (p=0·0005). INTERPRETATION: Adjunctive rifampicin provided no overall benefit over standard antibiotic therapy in adults with S aureus bacteraemia. FUNDING: UK National Institute for Health Research Health Technology Assessment
Delivery and Safety of a Two-Dose Preventive Ebola Virus Disease Vaccine in Pregnant and Non-Pregnant Participants during an Outbreak in the Democratic Republic of the Congo
During the 2018–2020 Ebola virus disease (EVD) outbreak, residents in Goma, Democratic Republic of the Congo, were offered a two-dose prophylactic EVD vaccine. This was the first study to evaluate the safety of this vaccine in pregnant women. Adults, including pregnant women, and children aged ≥1 year old were offered the Ad26.ZEBOV (day 0; dose 1), MVA-BN-Filo (day 56; dose 2) EVD vaccine through an open-label clinical trial. In total, 20,408 participants, including 6635 (32.5%) children, received dose 1. Fewer than 1% of non-pregnant participants experienced a serious adverse event (SAE) following dose 1; one SAE was possibly related to the Ad26.ZEBOV vaccine. Of the 1221 pregnant women, 371 (30.4%) experienced an SAE, with caesarean section being the most common event. No SAEs in pregnant women were considered related to vaccination. Of 1169 pregnancies with a known outcome, 55 (4.7%) ended in a miscarriage, and 30 (2.6%) in a stillbirth. Eleven (1.0%) live births ended in early neonatal death, and five (0.4%) had a congenital abnormality. Overall, 188/891 (21.1%) were preterm births and 79/1032 (7.6%) had low birth weight. The uptake of the two-dose regimen was high: 15,328/20,408 (75.1%). The vaccine regimen was well-tolerated among the study participants, including pregnant women, although further data, ideally from controlled trials, are needed in this crucial group
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