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1.
Nat Commun ; 15(1): 5192, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890288

RESUMO

Constraining the relationship between temperature and atmospheric concentrations of carbon dioxide (pCO2) is essential to model near-future climate. Here, we reconstruct pCO2 values over the past 15 million years (Myr), providing a series of analogues for possible near-future temperatures and pCO2, from a single continuous site (DSDP Site 467, California coast). We reconstruct pCO2 values using sterane and phytane, compounds that many phytoplankton produce and then become fossilised in sediment. From 15.0-0.3 Myr ago, our reconstructed pCO2 values steadily decline from 650 ± 150 to 280 ± 75 ppmv, mirroring global temperature decline. Using our new range of pCO2 values, we calculate average Earth system sensitivity and equilibrium climate sensitivity, resulting in 13.9 °C and 7.2 °C per doubling of pCO2, respectively. These values are significantly higher than IPCC global warming estimations, consistent or higher than some recent state-of-the-art climate models, and consistent with other proxy-based estimates.

2.
Malar J ; 22(1): 303, 2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37814260

RESUMO

BACKGROUND: Malaria is endemic and represents an important public health issue in Brazil. Knowledge of risk factors for disease progression represents an important step in preventing and controlling malaria-related complications. Reports of severe forms of Plasmodium vivax malaria are now becoming a common place, but respiratory complications are described in less than 3% of global literature on severe vivax malaria. CASE PRESENTATION: A severe respiratory case of imported vivax malaria in a previously healthy 40-year-old woman has been reported. The patient died after the fifth day of treatment with chloroquine and primaquine due to acute respiratory distress syndrome. CONCLUSIONS: Respiratory symptoms started 48 h after the initiation of anti-malarial drugs, raising the hypothesis that the drugs may have been involved in the genesis of the complication. The concept that vivax malaria is a benign disease that can sometimes result in the development of serious complications must be disseminated. This report highlights, once more, the crucial importance of malaria early diagnosis, a true challenge in non-endemic areas, where health personnel are not familiar with the disease and do not consider its diagnosis promptly.


Assuntos
Antimaláricos , Malária Vivax , Malária , Adulto , Feminino , Humanos , Antimaláricos/efeitos adversos , Malária/epidemiologia , Malária Vivax/complicações , Malária Vivax/tratamento farmacológico , Malária Vivax/diagnóstico , Plasmodium vivax , Primaquina/efeitos adversos
3.
Trends Parasitol ; 39(9): 749-759, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37451950

RESUMO

Wild animals are usually infected with parasites that can alter their hosts' trophic niches in food webs as can be seen from stable isotope analyses of infected versus uninfected individuals. The mechanisms influencing these effects of parasites on host isotopic values are not fully understood. Here, we develop a conceptual model to describe how the alteration of the resource intake or the internal resource use of hosts by parasites can lead to differences of trophic and isotopic niches of infected versus uninfected individuals and ultimately alter resource flows through food webs. We therefore highlight that stable isotope studies inferring trophic positions of wild organisms in food webs would benefit from routine identification of their infection status.


Assuntos
Parasitos , Animais , Isótopos de Carbono/análise , Isótopos de Nitrogênio/análise , Cadeia Alimentar , Animais Selvagens
4.
Anim Microbiome ; 5(1): 28, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-37189209

RESUMO

BACKGROUND: Our current understanding of vertebrate skin and gut microbiomes, and their vertical transmission, remains incomplete as major lineages and varied forms of parental care remain unexplored. The diverse and elaborate forms of parental care exhibited by amphibians constitute an ideal system to study microbe transmission, yet investigations of vertical transmission among frogs and salamanders have been inconclusive. In this study, we assess bacteria transmission in Herpele squalostoma, an oviparous direct-developing caecilian in which females obligately attend juveniles that feed on their mother's skin (dermatophagy). RESULTS: We used 16S rRNA amplicon-sequencing of the skin and gut of wild caught H. squalostoma individuals (males, females, including those attending juveniles) as well as environmental samples. Sourcetracker analyses revealed that juveniles obtain an important portion of their skin and gut bacteria communities from their mother. The contribution of a mother's skin to the skin and gut of her respective juveniles was much larger than that of any other bacteria source. In contrast to males and females not attending juveniles, only the skins of juveniles and their mothers were colonized by bacteria taxa Verrucomicrobiaceae, Nocardioidaceae, and Erysipelotrichaceae. In addition to providing indirect evidence for microbiome transmission linked to parental care among amphibians, our study also points to noticeable differences between the skin and gut communities of H. squalostoma and that of many frogs and salamanders, which warrants further investigation. CONCLUSION: Our study is the first to find strong support for vertical bacteria transmission attributed to parental care in a direct-developing amphibian species. This suggests that obligate parental care may promote microbiome transmission in caecilians.

5.
Mar Pollut Bull ; 186: 114369, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36462423

RESUMO

Methods that unambiguously prove microbial plastic degradation and allow for quantification of degradation rates are necessary to constrain the influence of microbial degradation on the marine plastic budget. We developed an assay based on stable isotope tracer techniques to determine microbial plastic mineralization rates in liquid medium on a lab scale. For the experiments, 13C-labeled polyethylene (13C-PE) particles (irradiated with UV-light to mimic exposure of floating plastic to sunlight) were incubated in liquid medium with Rhodococcus ruber as a model organism for proof of principle. The transfer of 13C from 13C-PE into the gaseous and dissolved CO2 pools translated to microbially mediated mineralization rates of up to 1.2 % yr-1 of the added PE. After incubation, we also found highly 13C-enriched membrane fatty acids of R. ruber including compounds involved in cellular stress responses. We demonstrated that isotope tracer techniques are a valuable tool to detect and quantify microbial plastic degradation.


Assuntos
Polietileno , Rhodococcus , Polietileno/metabolismo , Plásticos/metabolismo , Rhodococcus/metabolismo , Isótopos , Biodegradação Ambiental
7.
Chempluschem ; 88(2): e202200395, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36563109

RESUMO

Luminomagnetic composites have been synthesized that allow for an individual tuning of luminescence intensity, chromaticity and magnetization by combination of superparamagnetic, citrate-stabilized iron oxide nanoparticles with the luminescent MOFs 3 ∞ [Ln2 (BDC)3 (H2 O)4 ] (Ln=Eu, Tb; BDC2- =terephthalate). The components are arranged to a concept of inverse structuring compared to previous luminomagnetic composites with MOF@magnetic particle (shell@core) composition so that the luminescent MOF now acts as core and is covered by magnetic nanoparticles forming the satellite shell. Thereby, the magnetic and photophysical properties are individually tuneable between high emission intensity (1.2 ⋅ 106  cps mg-1 ) plus low saturation magnetization (6 emu g-1 ) and the direct opposite (0.09 ⋅ 106  cps mg-1 ; 42 emu g-1 ) by adjusting the particle coverage of the MOF. This is not achievable with a core-shell structure having a magnetic core and a dense MOF shell. The composition of the composites and the influence of different synthesis conditions on their properties were investigated by SEM/EDX, PXRD, magnetization measurements and photoluminescence spectroscopy.

8.
ScientificWorldJournal ; 2022: 7924600, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36408195

RESUMO

The proliferation of counterfeit and poor-quality drugs is a major public health problem, especially in developing countries such as Ghana where there are inadequate resources to effectively monitor their prevalence. Most of these drugs, which are counterfeited, are drugs, which are in high demand and will reap huge profits for the unscrupulous people who engage in such activities. The introduction of Omeprazole as one of the first-line therapies in the management of peptic and duodenal ulcers in the treatment guidelines of Ghana has resulted in many generics being introduced onto the market. The pharmaceutical quality of fifteen randomly sampled Omeprazole capsule brands in the Kumasi metropolis was assessed using the innovator brand as a comparator to confirm their suitability for patient use and to provide data for drug regulatory agencies in Ghana concerning poor quality omeprazole brands. All the sampled brands complied with the official specifications for identification with good primary and secondary packaging characteristics. Ninety-four (94%) of the sampled brands passed the uniformity of weight test. All the brands (n = 16) representing 100% passed the disintegration tests. Sixty percent (60%) of the sampled brands passed the drug content test. Ten brands (66.7%) met the specification for in vitro dissolution test. From f2 analysis, the dissolution profiles of only five brands (31%) were similar to that of the reference brand which indicated that they could be used interchangeably in clinical practice. Conclusively, ten out of the fifteen sampled brands were of good quality and only five could be used as a substitute for the innovator. Thus, regulatory agencies will need to strengthen their postmarket surveillance to ensure that generic brands of good quality are allowed onto the market.


Assuntos
Omeprazol , Humanos , Comprimidos , Cápsulas/química , Controle de Qualidade , Gana
9.
Thromb Res ; 218: 192-198, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36087355

RESUMO

INTRODUCTION: Lack of standardized definition impedes our ability to understand the clinical significance of asymptomatic central venous catheter (CVC) associated deep venous thrombosis (CADVT). Using standardized definitions, we aimed to determine the accuracy of physical examination in detecting CADVT in critically ill children and to identify characteristics associated with this accuracy. MATERIALS AND METHODS: In a post hoc study, we analyzed 236 children <18 years old admitted to the pediatric intensive care unit, had an untunneled CVC and surveilled for CADVT using ultrasound with paired physical examination. RESULTS: Of 236 paired examinations, 79 (33.5 %) had CADVT on ultrasound, while 56 (23.7 %) had signs of inflammation or venous obstruction on physical examination or CVC dysfunction. Sensitivity was 29.2 % (95 % confidence interval, CI: 19.9 %, 38.5 %), specificity was 80.2 % (95 % CI: 73.9 %, 86.4 %) and area under the receiver operating characteristic curve (AUROC) was 0.55 (95 % CI: 0.49, 0.60). When CVC dysfunction was excluded, sensitivity was lower (11.1 %; 95 % CI: 4.6 %, 17.6 %; p = 0.002), but specificity was higher (88.7 %; 95 % CI: 83.6 %, 93.7 %, p = 0.04). AUROC was 0.50 (95 % CI: 0.46, 0.54; p = 0.17). Use of point-of-care ultrasound and CVC inserted in the internal jugular vein (vs femoral vein) had lower sensitivity. Sepsis or infection and vasoactive support had lower specificity. Center of enrollment was associated with variable sensitivity. CONCLUSIONS: Physical examination has poor accuracy in detecting CADVT in critically ill children. Despite poor accuracy, physical examination that includes assessment of CVC dysfunction, in combination with imaging, is key to understanding the clinical significance of asymptomatic CADVT.


Assuntos
Cateteres Venosos Centrais , Trombose Venosa Profunda de Membros Superiores , Adolescente , Cateteres Venosos Centrais/efeitos adversos , Criança , Estado Terminal , Humanos , Veias Jugulares , Exame Físico
10.
Eur Heart J Acute Cardiovasc Care ; 11(7): 535-543, 2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35656797

RESUMO

AIMS: ST-depression and T-wave inversion are frequently present on the post-resuscitation electrocardiogram (ECG). However, the prognostic value of ischaemic ECG patterns is unknown. METHODS AND RESULTS: In this post-hoc subgroup analysis of the Coronary Angiography after Cardiac arrest (COACT) trial, the first in-hospital post-resuscitation ECG in out-of-hospital cardiac arrest patients with a shockable rhythm was analysed for ischaemic ECG patterns. Ischaemia was defined as ST-depression of ≥0.1 mV, T-wave inversion in ≥2 contiguous leads, or both. The primary endpoint was 90-day survival. Secondary endpoints were rate of acute unstable lesions, levels of serum troponin-T, and left ventricular function. Of the 510 out-of-hospital cardiac arrest patients, 340 (66.7%) patients had ischaemic ECG patterns. Patients with ischaemic ECG patterns had a worse 90-day survival compared with those without [hazard ratio 1.51; 95% confidence interval (CI) 1.08-2.12; P = 0.02]. A higher sum of ST-depression was associated with lower survival (log-rank = 0.01). The rate of acute unstable lesions (14.5 vs. 15.8%; odds ratio 0.90; 95% CI 0.51-1.59) did not differ between the groups. In patients with ischaemic ECG patterns, maximum levels of serum troponin-T (µg/L) were higher [0.595 (interquartile range 0.243-1.430) vs. 0.359 (0.159-0.845); ratio of geometric means 1.58; 1.13-2.20] and left ventricular function (%) was worse (44.7 ± 12.5 vs. 49.9 ± 13.3; mean difference -5.13; 95% CI -8.84 to -1.42). Adjusted for age and time to return of spontaneous circulation, ischaemic ECG patterns were no longer associated with survival. CONCLUSION: Post-arrest ischaemic ECG patterns were associated with worse 90-day survival. A higher sum of ST-depression was associated with lower survival. Adjusted for age and time to return of spontaneous circulation, ischaemic ECG patterns were no longer associated with survival.


Assuntos
Parada Cardíaca Extra-Hospitalar , Infarto do Miocárdio com Supradesnível do Segmento ST , Angiografia Coronária/métodos , Eletrocardiografia/métodos , Humanos , Parada Cardíaca Extra-Hospitalar/terapia , Troponina T
11.
BMC Palliat Care ; 21(1): 112, 2022 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-35739481

RESUMO

BACKGROUND: Palliative care for persons experiencing homelessness who reside in social service facilities is often late or lacking. A threefold intervention was implemented to improve palliative care for this population by increasing knowledge and collaboration between social service and palliative care professionals. This consultation service comprised: 1) consultations between social service professionals and palliative care professionals; 2) multidisciplinary meetings involving these professionals; and 3) training of these professionals. This study aims to evaluate the perceived added value of this threefold consultation service in three regions in the Netherlands. METHODS: A mixed-methods evaluation study using structured questionnaires for consultants, requesting consultants, and attendees of multidisciplinary meetings, semi-structured group and individual interviews with social service and palliative care professionals involved, weekly diaries filled out by consultants, and an implementation diary. Qualitative data were analyzed following the principles of thematic analysis. Quantitative data were analyzed descriptively. RESULTS: Thirty-four consultations, 22 multidisciplinary meetings and 9 training sessions were studied during the implementation period of 21 months. Social service professionals made up the majority of all professionals reached by the intervention. In all regions the intervention was perceived to have added value for collaboration and networks of social service and palliative care professionals (connecting disciplines reciprocally and strengthening collaborations), the competences of especially social service professionals involved (competency in palliative care provision, feeling emotionally supported in complex situations), and the quality and timing of palliative care (more focus on quality of life and dying, advance care planning and looking ahead, and greater awareness of death and palliative care). CONCLUSIONS: The threefold consultation service particularly helps social service professionals connect with palliative care professionals. It helps them to identify palliative care needs in good time and to provide qualitatively better palliative care to persons experiencing homelessness.


Assuntos
Pessoas Mal Alojadas , Assistência Terminal , Pessoas Mal Alojadas/psicologia , Humanos , Cuidados Paliativos/métodos , Pesquisa Qualitativa , Qualidade de Vida , Serviço Social , Assistência Terminal/métodos
12.
Chemistry ; 28(23): e202200881, 2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35352413

RESUMO

Invited for the cover of this issue are Klaus Müller-Buschbaum and co-workers at Giessen University. The image depicts an aluminium-based MOF as a novel material for the capture of iodine radioisotopes from a potential gas atmosphere exposure. Read the full text of the article at 10.1002/chem.202104171.


Assuntos
Iodo , Cátions , Humanos , Iodetos , Metais
13.
Chemistry ; 28(23): e202104171, 2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35179262

RESUMO

Eight cationic, two-dimensional metal-organic frameworks (MOFs) were synthesized in reactions of the group 13 metal halides AlBr3 , AlI3 , GaBr3 , InBr3 and InI3 with the dipyridyl ligands 1,2-di(4-pyridyl)ethylene (bpe), 1,2-di(4-pyridyl)ethane (bpa) and 4,4'-bipyridine (bipy). Seven of them follow the general formula 2 ∞ [MX2 (L)2 ]A, M=Al, In, X=Br, I, A- =[MX4 ]- , I- , I3 - , L=bipy, bpa, bpe. Thereby, the porosity of the cationic frameworks can be utilized to take up the heavy molecule iodine in gas-phase chemisorption vital for the capture of iodine radioisotopes. This is achieved by switching between I- and the polyiodide I3 - in the cavities at room temperature, including single-crystal-to-single-crystal transformation. The MOFs are 2D networks that exhibit (4,4)-topology in general or (6,3)-topology for 2 ∞ [(GaBr2 )2 (bpa)5 ][GaBr4 ]2 ⋅bpa. The two-dimensional networks can either be arranged to an inclined interpenetration of the cationic two-dimensional networks, or to stacked networks without interpenetration. Interpenetration is accompanied by polycatenation. Due to the cationic character, the MOFs require the counter ions [MX4 ]- , I- or I3 - counter ions in their pores. Whereas the [MX4 ]- , ions are immobile, iodide allows for chemisorption. Furthermore, eight additional coordination polymers and complexes were identified and isolated that elaborate the reaction space of the herein reported syntheses.

14.
J Am Heart Assoc ; 11(5): e022238, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35195012

RESUMO

Background In patients with out-of-hospital cardiac arrest without ST-segment elevation, immediate coronary angiography did not improve clinical outcomes when compared with delayed angiography in the COACT (Coronary Angiography After Cardiac Arrest) trial. Whether 1 of the 2 strategies has benefits in terms of health care resource use and costs is currently unknown. We assess the health care resource use and costs in patients with out-of-hospital cardiac arrest. Methods and Results A total of 538 patients were randomly assigned to a strategy of either immediate or delayed coronary angiography. Detailed health care resource use and cost-prices were collected from the initial hospital episode. A generalized linear model and a gamma distribution were performed. Generic quality of life was measured with the RAND-36 and collected at 12-month follow-up. Overall total mean costs were similar between both groups (EUR 33 575±19 612 versus EUR 33 880±21 044; P=0.86). Generalized linear model: (ß, 0.991; 95% CI, 0.894-1.099; P=0.86). Mean procedural costs (coronary angiography and percutaneous coronary intervention, coronary artery bypass graft) were higher in the immediate angiography group (EUR 4384±3447 versus EUR 3028±4220; P<0.001). Costs concerning intensive care unit and ward stay did not show any significant difference. The RAND-36 questionnaire did not differ between both groups. Conclusions The mean total costs between patients with out-of-hospital cardiac arrest randomly assigned to an immediate angiography or a delayed invasive strategy were similar during the initial hospital stay. With respect to the higher invasive procedure costs in the immediate group, a strategy awaiting neurological recovery followed by coronary angiography and planned revascularization may be considered. Registration URL: https://trialregister.nl; Unique identifier: NL4857.


Assuntos
Parada Cardíaca Extra-Hospitalar , Intervenção Coronária Percutânea , Angiografia Coronária/métodos , Custos e Análise de Custo , Humanos , Parada Cardíaca Extra-Hospitalar/diagnóstico por imagem , Parada Cardíaca Extra-Hospitalar/terapia , Qualidade de Vida , Resultado do Tratamento
15.
Int J Food Sci ; 2022: 6869122, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35111843

RESUMO

Pharmaceutical oral solutions are preparations in which the active ingredients are dissolved in suitable liquid vehicles such as syrups. This study sought to determine the potential of glucose syrup produced from high quality cassava flour (HQCF) as a vehicle or sweetener in the preparation of paracetamol syrup and simple linctus. Four formulations (two paracetamol syrups (B1 and B2) and two simple linctus formulations (A1 and A2)) were prepared using glucose syrup from HQCF as vehicle or sweetener while two controls (B3 and A3) were prepared for each group using sucrose syrup as vehicle or sweetener. Two brands of paracetamol syrup and simple linctus were purchased from retail pharmacies to serve as standards. Physical and organoleptic parameters such as pH, taste and color, microbial load, and drug content of all formulations were determined. All formulations passed the microbial load and drug content tests as specified by the British Pharmacopoeia. The paracetamol syrups were all sweet with characteristic bitter aftertastes except formulation B2 which was sweetened with sucralose. All the simple linctus formulations were sweet except A2 (sweetened with sucralose) which was very sweet. The taste masking capacity of the glucose syrup produced from HQCF matched that of the sucrose syrup in the products formulated. Therefore, glucose syrup from HQCF could be a suitable alternative to sucrose syrup as a vehicle or sweetener in oral liquid formulations and can ultimately reduce the cost of these oral liquid formulations.

16.
Crit Care Med ; 50(2): e129-e142, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34637414

RESUMO

OBJECTIVES: The optimal targeted temperature in patients with shockable rhythm is unclear, and current guidelines recommend targeted temperature management with a correspondingly wide range between 32°C and 36°C. Our aim was to study survival and neurologic outcome associated with targeted temperature management strategy in postarrest patients with initial shockable rhythm. DESIGN: Observational substudy of the Coronary Angiography after Cardiac Arrest without ST-segment Elevation trial. SETTING: Nineteen hospitals in The Netherlands. PATIENTS: The Coronary Angiography after Cardiac Arrest trial randomized successfully resuscitated patients with shockable rhythm and absence of ST-segment elevation to a strategy of immediate or delayed coronary angiography. In this substudy, 459 patients treated with mild therapeutic hypothermia (32.0-34.0°C) or targeted normothermia (36.0-37.0°C) were included. Allocation to targeted temperature management strategy was at the discretion of the physician. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: After 90 days, 171 patients (63.6%) in the mild therapeutic hypothermia group and 129 (67.9%) in the targeted normothermia group were alive (hazard ratio, 0.86 [95% CI, 0.62-1.18]; log-rank p = 0.35; adjusted odds ratio, 0.89; 95% CI, 0.45-1.72). Patients in the mild therapeutic hypothermia group had longer ICU stay (4 d [3-7 d] vs 3 d [2-5 d]; ratio of geometric means, 1.32; 95% CI, 1.15-1.51), lower blood pressures, higher lactate levels, and increased need for inotropic support. Cerebral Performance Category scores at ICU discharge and 90-day follow-up and patient-reported Mental and Physical Health Scores at 1 year were similar in the two groups. CONCLUSIONS: In the context of out-of-hospital cardiac arrest with shockable rhythm and no ST-elevation, treatment with mild therapeutic hypothermia was not associated with improved 90-day survival compared with targeted normothermia. Neurologic outcomes at 90 days as well as patient-reported Mental and Physical Health Scores at 1 year did not differ between the groups.


Assuntos
Angiografia Coronária/métodos , Cardioversão Elétrica/estatística & dados numéricos , Hipotermia Induzida/normas , Parada Cardíaca Extra-Hospitalar/terapia , Idoso , Angiografia Coronária/estatística & dados numéricos , Feminino , Humanos , Hipotermia Induzida/métodos , Hipotermia Induzida/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Países Baixos , Parada Cardíaca Extra-Hospitalar/epidemiologia , Ressuscitação/métodos , Ressuscitação/estatística & dados numéricos , Resultado do Tratamento
17.
Mol Ecol ; 31(15): 3979-3998, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-34516675

RESUMO

Secondary sympatry amongst sister lineages is strongly associated with genetic and ecological divergence. This pattern suggests that for closely related species to coexist in secondary sympatry, they must accumulate differences in traits that mediate ecological and/or reproductive isolation. Here, we characterized inter- and intraspecific divergence in three giant tree frog species whose distributions stretch across West and Central Africa. Using genome-wide single-nucleotide polymorphism data, we demonstrated that species-level divergence coincides temporally and geographically with a period of large-scale forest fragmentation during the late Pliocene. Our environmental niche models further supported a dynamic history of climatic suitability and stability, and indicated that all three species occupy distinct environmental niches. We found modest morphological differentiation amongst the species with significant divergence in tympanum diameter and male advertisement call. In addition, we confirmed that two species occur in secondary sympatry in Central Africa but found no evidence of hybridization. These patterns support the hypothesis that cycles of genetic exchange and isolation across West and Central Africa have contributed to globally significant biodiversity. Furthermore, divergence in both ecology and reproductive traits appear to have played important roles in maintaining distinct lineages. At the intraspecific level, we found that climatic refugia, precipitation gradients, marine incursions, and potentially riverine barriers generated phylogeographic structure throughout the Pleistocene and into the Holocene. Further studies examining phenotypic divergence and secondary contact amongst these geographically structured populations may demonstrate how smaller scale and more recent biogeographic barriers contribute to regional diversification.


La sympatrie secondaire parmi les espèces sœurs est fortement associée à la divergence génétique et écologique. Ce modèle suggère que pour que des espèces étroitement liées coexistent en sympatrie secondaire, elles doivent accumuler des différences dans les traits qui contribuent à l'isolement écologique ou reproductif. Ici, nous avons caractérisé la divergence inter- et intra-spécifique chez trois espèces de grenouilles arboricoles géantes dont les distributions s'étendent à travers l'Afrique de l'Ouest et Centrale. Avec des données génétiques, nous avons démontré que la divergence au niveau des espèces coïncide temporellement et géographiquement avec une période de fragmentation forestière à la fin du Pliocène. Nos modèles de niches environnementales ont soutenu une histoire dynamique de stabilité climatique, et ont indiqué que les trois espèces occupent des niches environnementales distinctes. Nous avons trouvé une différenciation morphologique modeste parmi les trois espèces mais une divergence significative dans le diamètre du tympan et les cris des mâles. De plus, nous avons confirmé que deux espèces sont présentes en sympatrie secondaire en Afrique Centrale mais n'avons trouvé aucune preuve d'hybridation. Ces résultats soutiennent l'hypothèse que les cycles d'échange génétique et d'isolement à travers l'Afrique de l'Ouest et Centrale ont contribué à une profonde concentration de biodiversité dans la région. De plus, la divergence des traits écologiques et reproducteurs semble avoir joué un rôle important dans le maintien de lignées distinctes. Au niveau intra-spécifique, nous avons constaté que les refuges climatiques, les gradients de précipitation, les incursions marines et potentiellement les barrières fluviales ont généré une structure phylogéographique pendant le Pléistocène et jusqu'à l'Holocène. Des études examinant la divergence phénotypique et le contact secondaire entre ces populations géographiquement structurées pourraient démontrer comment des barrières biogéographiques à échelle plus petite et plus récentes contribuent à la diversification régionale.


Assuntos
Anuros , Biodiversidade , África Central , Animais , Anuros/genética , DNA Mitocondrial/genética , Florestas , Variação Genética , Masculino , Filogenia , Filogeografia , Ranidae/genética
18.
J Anim Ecol ; 91(2): 356-366, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34753198

RESUMO

Variation in foraging tactics and diet is usually attributed to differences in morphology, experience and prey availability. Recently, consistent individual differences in behaviour (personality) have been shown to be associated with foraging strategies. Bolder or more exploratory individuals are predicted to have a faster pace-of-life and offset the costs of moving more or in risky areas, with higher energetic gains by encountering profitable foraging opportunities and prey. However, the relationship between personality, foraging and diet is poorly understood. We investigated how exploratory behaviour in red knots Calidris canutus is associated with foraging tactics and diet by combining laboratory experiments, field observations and stable isotope analysis. First, we developed a mobile experimental arena to measure exploration speed in controlled settings. We validated the method by repeated testing of individuals over time and contexts. This setup allowed us to measure exploratory personality at the field site, eliminating the need to bring birds into captivity for long periods of time. After releasing birds within days of their capture, we asked whether exploration speed was associated with differences in foraging tactics and diet in the wild. We found that tactile foraging red knots mainly caught hard-shelled prey that are buried in the sediment, whereas visual foraging knots only captured soft preys located close to or on the surface. We also found that faster explorers showed a higher percentage of visual foraging than slower explorers. By contrast, morphology (bill length and gizzard size) had no significant effect on foraging tactics. Diet analysis based on δ15 N and δ13 C stable isotope values of plasma and red blood cells confirmed our field observations with slower explorers mainly consumed hard-shelled prey while faster explorers consumed more soft than hard-shelled prey. Our results show that foraging tactics and diet are associated with a personality trait, independent of morphological differences. We discuss how consistent behaviour might develop early in life through positive feedbacks between foraging tactics, prey type and foraging efficiency.


Assuntos
Comportamento Apetitivo , Charadriiformes , Comportamento Exploratório , Comportamento Alimentar , Animais , Dieta/veterinária
19.
Biomed Res Int ; 2021: 6002286, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34888384

RESUMO

Polymeric materials from plants continue to be of interest to pharmaceutical scientists as potential binders in immediate release tablets due to availability, sustainability, and constant supply to feed local pharmaceutical industries. Paracetamol tablet formulations were utilized in investigating the potential binding characteristics of pectin harnessed from various okra genotypes (PC1-PC5) in Ghana. The pectin yields from the different genotypes ranged from 6.12 to 18.84%w/w. The pH of extracted pectin ranged from 6.39 to 6.92, and it had good swelling indices and a low moisture content. Pectin extracted from all genotypes were evaluated as binders (10, 15, and 20%w/v) and compared to tragacanth BP. All formulated tablets (F1-F18) passed the weight uniformity, drug content, hardness, and friability tests. Based on their crushing strength, tablets prepared with pectin from the various genotypes were relatively harder (P ≤ 0.05) than tablets prepared with tragacanth BP. Tablets prepared with pectins as binders at 10%w/v and 15%w/v passed the disintegration and dissolution tests with the exception of PC4 at 15%w/v. Incorporation of pectin from all genotypes (excluding PC5) as a binder at concentrations above 15%w/v (F13, F16, F14, and F15) produced tablets which failed the disintegration test and showed poor dissolution profiles. Thus, pectin from these genotypes can be industrially commodified as binders in immediate release tablets using varying concentrations.


Assuntos
Abelmoschus/química , Pectinas/química , Comprimidos/química , Acetaminofen/química , Química Farmacêutica/métodos , Excipientes/química , Genótipo , Gana , Solubilidade/efeitos dos fármacos
20.
R Soc Open Sci ; 8(12): 210949, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34909214

RESUMO

Baleen from mysticete whales is a well-preserved proteinaceous material that can be used to identify migrations and feeding habits for species whose migration pathways are unknown. Analysis of δ13C and δ15N values from bulk baleen have been used to infer migration patterns for individuals. However, this approach has fallen short of identifying migrations between regions as it is difficult to determine variations in isotopic shifts without temporal sampling of prey items. Here, we apply analysis of δ15N values of amino acids to five baleen plates belonging to three species, revealing novel insights on trophic position, metabolic state and migration between regions. Humpback and minke whales had higher reconstructed trophic levels than fin whales (3.7-3.8 versus 3-3.2, respectively) as expected due to different feeding specialization. Isotopic niche areas between baleen minima and maxima were well separated, indicating regional resource use for individuals during migration that aligned with isotopic gradients in Atlantic Ocean particulate organic matter. Phenylanine δ15N values confirmed regional separation between the niche areas for two fin whales as migrations occurred and elevated glycine and threonine δ15N values suggested physiological changes due to fasting. Simultaneous resolution of trophic level and physiological changes allow for identification of regional migrations in mysticetes.

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