RESUMO
The Greater Cape Floristic Region (GCFR) is renowned for its exceptional biodiversity, accommodating over 11 000 plant species, notable degree of endemism, and substantial diversification within limited plant lineages, a phenomenon ascribed to historical radiation events. While both abiotic and biotic factors contribute to this diversification, comprehensive genomic alterations, recognized as pivotal in the diversification of angiosperms, are perceived as uncommon. This investigation focuses on the genus Pteronia, a prominent representative of the Asteraceae family in the GCFR. Employing NGS-based HybSeq and RADSeq methodologies, flow cytometry, karyology, and ecological modeling, we scrutinize the intricacies of its polyploid evolution. Phylogenetic reconstructions using 951 low-copy nuclear genes confirm Pteronia as a well-supported, distinct clade within the tribe Astereae. The ingroup displays a structure indicative of rapid radiation likely antedating polyploid establishment, with the two main groups demarcated by their presence or absence in the fynbos biome. Genome size analysis encompasses 1293 individuals across 347 populations, elucidating significant variation ranging from 6.1 to 34.2 pg (2C-value). Pteronia demonstrates substantially large genome sizes within Astereae and phanerophytes. Polyploidy is identified in 31% of the studied species, with four discerned ploidy levels (2x, 4x, 6x, 8x). Cytotypes exhibit marked distinctions in environmental traits, influencing their distribution across biomes and augmenting their niche differentiation. These revelations challenge the presumed scarcity of polyploidy in the Cape flora, underscoring the imperative need for detailed population studies. The intricate evolutionary history of Pteronia, characterized by recent polyploidy and genome size variation, contributes substantially to the comprehension of diversification patterns within the GCFR biodiversity hotspot.
Assuntos
Asteraceae , Diploide , Genoma de Planta , Filogenia , Poliploidia , Genoma de Planta/genética , Asteraceae/genética , Tamanho do Genoma , Evolução Biológica , Biodiversidade , Evolução MolecularRESUMO
BACKGROUND: The treatment of spinal cord injury (SCI) has always been a significant research focus of clinical neuroscience, with inhibition of microglia-mediated neuro-inflammation as well as oxidative stress key to successful SCI patient treatment. Caffeic acid phenethyl ester (CAPE), a compound extracted from propolis, has both anti-inflammatory and anti-oxidative effects, but its SCI therapeutic effects have rarely been reported. METHODS: We constructed a mouse spinal cord contusion model and administered CAPE intraperitoneally for 7 consecutive days after injury, and methylprednisolone (MP) was used as a positive control. Hematoxylin-eosin, Nissl, and Luxol Fast Blue staining were used to assess the effect of CAPE on the structures of nervous tissue after SCI. Basso Mouse Scale scores and footprint analysis were used to explore the effect of CAPE on the recovery of motor function by SCI mice. Western blot analysis and immunofluorescence staining assessed levels of inflammatory mediators and oxidative stress-related proteins both in vivo and in vitro after CAPE treatment. Further, reactive oxygen species (ROS) within the cytoplasm were detected using an ROS kit. Changes in mitochondrial membrane potential after CAPE treatment were detected with 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-imidacarbocyanine iodide. Mechanistically, western blot analysis and immunofluorescence staining were used to examine the effect of CAPE on the SIRT1/PGC1α/DRP1 signaling pathway. RESULTS: CAPE-treated SCI mice showed less neuronal tissue loss, more neuronal survival, and reduced demyelination. Interestingly, SCI mice treated with CAPE showed better recovery of motor function. CAPE treatment reduced the expression of inflammatory and oxidative mediators, including iNOS, COX-2, TNF-α, IL-1ß, 1L-6, NOX-2, and NOX-4, as well as the positive control MP both in vitro and in vivo. In addition, molecular docking experiments showed that CAPE had a high affinity for SIRT1, and that CAPE treatment significantly activated SIRT1 and PGC1α, with down-regulation of DRP1. Further, CAPE treatment significantly reduced the level of ROS in cellular cytoplasm and increased the mitochondrial membrane potential, which improved normal mitochondrial function. After administering the SIRT1 inhibitor nicotinamide, the effect of CAPE on neuro-inflammation and oxidative stress was reversed.On the contrary, SIRT1 agonist SRT2183 further enhanced the anti-inflammatory and antioxidant effects of CAPE, indicating that the anti-inflammatory and anti-oxidative stress effects of CAPE after SCI were dependent on SIRT1. CONCLUSION: CAPE inhibits microglia-mediated neuro-inflammation and oxidative stress and supports mitochondrial function by regulating the SIRT1/PGC1α/DRP1 signaling pathway after SCI. These effects demonstrate that CAPE reduces nerve tissue damage. Therefore, CAPE is a potential drug for the treatment of SCI through production of anti-inflammatory and anti-oxidative stress effects.
Assuntos
Ácidos Cafeicos , Doenças Mitocondriais , Álcool Feniletílico , Traumatismos da Medula Espinal , Animais , Camundongos , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Anti-Inflamatórios/metabolismo , Ácidos Cafeicos/farmacologia , Ácidos Cafeicos/uso terapêutico , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Metilprednisolona/farmacologia , Doenças Mitocondriais/tratamento farmacológico , Doenças Mitocondriais/metabolismo , Simulação de Acoplamento Molecular , Estresse Oxidativo/efeitos dos fármacos , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Álcool Feniletílico/análogos & derivados , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Sirtuína 1/metabolismo , Medula Espinal , Traumatismos da Medula Espinal/tratamento farmacológico , Dinaminas/efeitos dos fármacosRESUMO
Plants employ a diversity of reproductive safeguarding strategies to circumvent the challenge of pollen limitation. Focusing on southern African Lachenalia (Asparagaceae: Scilloideae), we test the hypothesis that the evolution of reproductive safeguarding traits (self-compatibility, autonomous selfing, bird pollination and clonal propagation) is favoured in species occupying conditions of low insect abundance imposed by critically infertile fynbos heathland vegetation and by flowering outside the austral spring insect abundance peak. We trace the evolution of these traits and selective regimes on a dated, multi-locus phylogeny of Lachenalia and assess their evolutionary associations using ordinary and phylogenetic regression. Ancestral state reconstructions identify an association with non-fynbos vegetation and spring flowering as ancestral in Lachenalia, the transition to fynbos vegetation and non-spring flowering taking place multiple times. They also show that self-compatibility, autofertility, bird pollination and production of multiple clonal offsets have evolved repeatedly. Regression models suggest that bird pollination and self-compatibility are selected for in fynbos and in non-spring flowering lineages, with autofertility being positively associated with non-spring flowering. These patterns support the interpretation of these traits as reproductive safeguarding adaptations under reduced insect pollinator abundance. We find no evidence to support the interpretation of clonal propagation as a reproductive safeguarding strategy.
RESUMO
Interrogating the ecological and geographic factors that influence population divergence dynamics can reveal why some groups of organisms diversify more prolifically than others. One such group is the heathers (Erica, Ericaceae), the largest plant genus in the Cape Floristic Region. We study Erica abietina, a highly variable species complex with four subspecies differing in geographic range, habitat and pollination syndrome. We test for population differentiation, hybridisation, introgression and pollinator-driven divergence using genotyping-by-sequencing on samples across the entire distribution. We find five variably distinct genetic groups, with one subspecies comprising two independent lineages that are geographically isolated and occur on different soil types. Phylogenetic analysis suggests two independent shifts between bird and insect pollination, with accompanying genetic divergence. However, for one pair of populations with different pollinators, we uncover several individuals of hybrid origin at a site of sympatry. These results suggest that floral differentiation driven by divergent selection acts in concert with geographic isolation to maintain reproductive isolation and promote speciation. Our investigations reveal a highly dynamic system whose diversity has been shaped by a variety of interacting forces. We suggest that such a system could be a model for much of the diversification of the Cape flora.
RESUMO
Recent advances in sequencing technology and phylogenetic methods allow us to solve puzzling taxonomic questions using detailed analyses of genetic diversity of populations and gene flow between them. The genus of solitary-living dune mole-rat, Bathyergus, is quite unique among six genera of African mole-rats. The animals are by far the largest and the only scratch digging mole-rat genus possessing a skull less adapted to digging, grooved upper incisors, and more surface locomotor activity. Most authors recognize two species of dune mole-rats, B. suillus and B. janetta, but according to others, the genus is monotypic. In addition, recent molecular studies have revealed cryptic genetic diversity and suggested the existence of up to four species. In our study, we used mitochondrial and genome-wide nuclear data collected throughout the distribution of the genus to investigate the number of species. In agreement with previous studies, we found Bathyergus to be differentiated into several distinct lineages, but we also found evidence for a degree of gene flow between some of them. Furthermore, we confirmed that B. janetta is nested within B. suillus, making the latter paraphyletic and we documented an instance of local mitochondrial introgression between these two nominal species. Phylogeographic structure of the genus was found to be very shallow. Although traditionally dated to the Miocene, we found the first split within the genus to be much younger estimated to 0.82 Ma before present. Genealogical distinctiveness of some lineages was very low, and the coancestry matrix showed extensive sharing of closely related haplotypes throughout the genus. Accordingly, Infomap clustering on the matrix showed all populations to form a single cluster. Overall, our study tends to support the existence of only one species of Bathyergus namely, B. suillus. Environmental niche modelling confirmed its dependence on sandy soils and the preference for soils with relatively high carbon content. Bayesian skyline plots indicate recent population decline in the janetta lineage, probably related to global environmental change.
Assuntos
DNA Mitocondrial , Fluxo Gênico , Variação Genética , Ratos-Toupeira , Filogenia , Animais , Ratos-Toupeira/genética , Ratos-Toupeira/classificação , DNA Mitocondrial/genética , Teorema de Bayes , Análise de Sequência de DNA , Núcleo Celular/genética , ÁfricaRESUMO
The tropical shrub Coelospermum decipiens (Rubiaceae) is an extreme selenium (Se) hyperaccumulator, reported to accumulate up to 1140 µg Se g-1 when found growing on soils with Se
RESUMO
PREMISE: Increases in genome size in plants-often associated with larger, low-density stomata and greater water-use efficiency (WUE)-could affect plant ecophysiological and hydraulic function. Variation in plant genome size is often due to polyploidy, having occurred repeatedly in the austral sedge genus Schoenus in the Cape Floristic Region (CFR), while species in the other major schoenoid genus in the region, Tetraria, have smaller genomes. Comparing these genera is useful as they co-occur at the landscape level, under broadly similar bioclimatic conditions. We hypothesized that CFR Schoenus have greater WUE, with lower maximum stomatal conductance (gwmax) imposed by larger, less-dense stomata. METHODS: We investigated relationships between genome size and stomatal parameters in a phylogenetic context, reconstructing a phylogeny of CFR-occurring Schoeneae (Cyperaceae). Species' stomatal and functional traits were measured from field-collected and herbarium specimens. Carbon stable isotopes were used as an index of WUE. Genome size was derived from flow-cytometric measurements of leafy shoots. RESULTS: Evolutionary regressions demonstrated that stomatal size and density covary with genome size, positively and negatively, respectively, with genome size explaining 72-75% of the variation in stomatal size. Larger-genomed species had lower gwmax and C:N ratios, particularly in culms. CONCLUSIONS: We interpret differences in vegetative physiology between the genera as evidence of more-conservative strategies in CFR Schoenus compared to the more-acquisitive Tetraria. Because Schoenus have smaller, reduced leaves, they likely rely more on culm photosynthesis than Tetraria. Across the CFR Schoeneae, ecophysiology correlates with genome size, but confounding sources of trait variation limit inferences about causal relationships between traits.
Assuntos
Tamanho do Genoma , Genoma de Planta , Filogenia , Estômatos de Plantas , Estômatos de Plantas/fisiologia , Estômatos de Plantas/genética , Cyperaceae/genética , Cyperaceae/fisiologia , Água/fisiologia , Folhas de Planta/fisiologia , Folhas de Planta/genética , Folhas de Planta/anatomia & histologiaRESUMO
The identification of unknown human remains is a significant and ongoing challenge in South Africa, worsened by the country's high murder rate. The rate of decomposition in South Africa is significantly influenced by vertebrate scavenging, which, if not considered, can impede the accurate estimation of the post-mortem interval. Scavenging patterns vary greatly depending on the environment and ecological region, and there is limited data for the Western Cape province. To address this gap, two clothed and uncaged pig carcasses weighing 60 kg each were placed in the field in July 2021 and January 2022, respectively. Motion-activated infrared-capable trail cameras were used to observe decomposition, scavenger species, and their activities. Additionally, a comparative sample of 16 unclothed carcasses deployed between 2014 and 2016 in the same habitat were analyzed to assess the impact of clothing and biomass load. The study found three main results: (1) Regardless of habitat or biomass load, it took significantly less time to reach decomposition milestones (25%, 50%, and 75%) during the summer season; (2) the presence of mongoose scavengers had a greater impact on the time required to reach milestones during winter compared to summer; and (3) single carcass deployments reached the milestones faster than multi-carcass deployments in both seasons. This research highlights the potential inaccuracy of current methods for estimating the post-mortem interval when scavenging activity is not considered or documented in the underlying experimental data, particularly for environments or ecological biomes where scavengers actively impact decomposition rates.
Assuntos
Biomassa , Vestuário , Comportamento Alimentar , Mudanças Depois da Morte , Estações do Ano , Animais , África do Sul , Suínos , Modelos Animais , Patologia Legal/métodosRESUMO
In 2023, passive laboratory-based surveillance showed an increase in hepatitis A virus (HAV) infection. We investigated hepatitis A incidence using the notifiable medical condition surveillance system (NMCSS) data and molecularly characterised positive blood samples from the Western Cape province for 2023. All HAV IgM seropositive cases from the NMCSS from 1 January to 31 October 2023 in South Africa were investigated. HAV RNA from blood samples that had tested positive for HAV IgM from Western Cape was amplified in the VP1/P2B junction and sequenced (3500Xl Genetic Analyser). Sequences were assembled, aligned (Sequencher) and analysed (Aliview 1.27 and MEGA11). Statistical analysis was performed using Excel and the CuSum2 Threshold to determine suspected outbreaks. In 2023, the incidence of HAV IgM was 6.28/100,000 in South Africa, with the highest incidence in Western Cape province (15.86/100,000). Children aged 5 to 14 years were affected the most in the Western Cape. The positive cases in the Western Cape were above the CuSum2 threshold from January to May 2023, with the highest incidence observed in the City of Cape Town Metropolitan (14.8/100,000). Genotyping was successfully performed on 92.7% (139/150) of serum samples, for which the IB sub-genotype was detected. Three primary mutations R63K, R71S and M104I were observed in more than 49% of the samples. Most of the samples sequenced belonged to patients residing in areas close to each other within the City of Cape Town Southern, Western, and Mitchells Plain sub-districts. The CuSum2 threshold method allowed the identification of suspected HAV outbreaks in the districts within the Western Cape in 2023 while genotyping identified clusters of sub-genotype IB. Genotyping could assist with determining the common source of infection during an outbreak, especially if coupled with epidemiological and geographical data. Further active surveillance can assist in investigating the HAV risk factors for targeted public health responses.
Assuntos
Hepatite A , Filogenia , RNA Viral , Humanos , África do Sul/epidemiologia , Hepatite A/epidemiologia , Hepatite A/virologia , Pré-Escolar , Criança , Adolescente , Masculino , Adulto , Feminino , Adulto Jovem , Pessoa de Meia-Idade , Incidência , Lactente , RNA Viral/genética , Genótipo , Imunoglobulina M/sangue , Vírus da Hepatite A/genética , Vírus da Hepatite A/classificação , Vírus da Hepatite A/isolamento & purificação , Idoso , Surtos de Doenças , Anticorpos Anti-Hepatite A/sangueRESUMO
INTRODUCTION: Tuberculosis is a global health problem that causes 1. 4 million deaths every year. It has been estimated that sputum smear-negative diagnosis but culture-positive pulmonary TB diagnosis contribute to 12.6% of pulmonary TB transmission. TB diagnosis by smear microscopy smear has a minimum detection limit (LOD) of 5,000 to 10,000 bacilli per milliliter (CFU/ml) of sputum result in missed cases and false positives. However, GeneXpert technology, with a LOD of 131-250 CFU/ml in sputum samples and its implementation is believe to facilitate early detection TB and drug-resistant TB case. Since 2013, Ghana health Service (GHS) introduce GeneXpert MTB/RIF diagnostic in all regional hospitals in Ghana, however no assessment of performance between microscopy and GeneXpert TB diagnosis cross the health facilities has been reported. The study compared the results of routine diagnoses of TB by microscopy and Xpert MTB from 2016 to 2020 at the Cape Coast Teaching Hospital (CCTH). METHODS: The study compared routine microscopic and GeneXpert TB diagnosis results at the Cape Coast Teaching Hospital (CCTH) from 2016 to 2020 retrospectively. Briefly, sputum specimens were collected into 20 mL sterile screw-capped containers for each case of suspected TB infection and processed within 24 h. The samples were decontaminated using the NALC-NaOH method with the final NaOH concentration of 1%. The supernatants were discarded after the centrifuge and the remaining pellets dissolved in 1-1.5 ml of phosphate buffer saline (PBS) and used for diagnosis. A fixed smears were Ziehl-Neelsen acid-fast stain and observed under microscope and the remainings were used for GeneXpert MTB/RIF diagnosis. The data were analyze using GraphPad Prism. RESULTS: 50.11% (48.48-51.38%) were females with an odd ratio (95% CI) of 1.004 (0.944-1.069) more likely to report to the TB clinic for suspected TB diagnosis. The smear-positive cases for the first sputum were 6.6% (5.98-7.25%), and the second sputum was 6.07% (5.45-6.73%). The Xpert MTB-RIF diagnosis detected 2.93% (10/341) (1.42-5.33%) in the first and 5.44% (16/294) (3.14-8.69%) in the second smear-negative TB samples. The prevalence of Xpert MTB-RIF across smear positive showed that males had 56.87% (178/313) and 56.15% (137/244) and females had 43.13% (135/313) and 43.85% (107/244) for the first and second sputum. Also, false negative smears were 0.18% (10/5607) for smear 1 and 0.31% (16/5126) for smear 2. CONCLUSION: In conclusion, the study highlights the higher sensitivity of the GeneXpert assay compared to traditional smear microscopy for detecting MTB. The GeneXpert assay identified 10 and 16 positive MTB from smear 1 and smear 2 samples which were microscopic negative.
Assuntos
Hospitais de Ensino , Microscopia , Mycobacterium tuberculosis , Escarro , Tuberculose Pulmonar , Humanos , Mycobacterium tuberculosis/isolamento & purificação , Mycobacterium tuberculosis/genética , Estudos Retrospectivos , Escarro/microbiologia , Gana/epidemiologia , Feminino , Adulto , Masculino , Microscopia/métodos , Pessoa de Meia-Idade , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/microbiologia , Adulto Jovem , Adolescente , Sensibilidade e Especificidade , Idoso , Técnicas de Diagnóstico Molecular/métodos , Criança , Pré-EscolarRESUMO
The deadliest type of skin cancer, malignant melanoma, is also the reason for the majority of skin cancer-related deaths. The objective of this article was to investigate the efficiency of free caffeic acid phenethyl ester (CAPE) and liposomal CAPE in inducing apoptosis in melanoma cells (A375) in in vitro. CAPE was loaded into liposomes made up of hydrogenated soybean phosphatidylcholine, cholesterol, and 1,2-distearoyl-sn-glycero-3 phosphoethanolamine-N-[methoxy (polyethylene glycol)-2000], and their physicochemical properties were assessed. (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test was performed for comparing the cytotoxicity of free CAPE and liposomal CAPE at dosages of 10, 15, 25, 50, 75 and the highest dose of 100 µg/mL for period of 24 and 48 h on A375 cell line to calculate IC50. Apoptosis and necrosis were evaluated in A375 melanoma cancer cells using flow cytometry. Atomic force microscopy was utilized to determine the nanomechanical attributes of the membrane structure of A375 cells. To determine whether there were any effects on apoptosis, the expression of PI3K/AKT1 and BAX/BCL2 genes was analyzed using the real-time polymerase chain reaction technique. According to our results, the maximum amount of drug release from nanoliposomes was determined to be 91% and the encapsulation efficiency of CAPE in liposomes was 85.24%. Also, the release of free CAPE was assessed to be 97%. Compared with liposomal CAPE, free CAPE showed a greater effect on reducing the cancer cell survival after 24 and 48 h. Therefore, IC50 values of A375 cells treated with free and liposomal CAPE were calculated as 47.34 and 63.39 µg/mL for 24 h. After 48 h of incubation of A375 cells with free and liposomal CAPE, IC50 values were determined as 30.55 and 44.83 µg/mL, respectively. The flow cytometry analysis revealed that the apoptosis induced in A375 cancer cells was greater when treated with free CAPE than when treated with liposomal CAPE. The highest nanomechanical changes in the amount of cell adhesion forces, and elastic modulus value were seen in free CAPE. Subsequently, the greatest decrease in PI3K/AKT1 gene expression ratio occurred in free CAPE.
Assuntos
Melanoma , Álcool Feniletílico , Neoplasias Cutâneas , Humanos , Melanoma/tratamento farmacológico , Melanoma/patologia , Linhagem Celular Tumoral , Lipossomos , Álcool Feniletílico/farmacologia , Álcool Feniletílico/uso terapêutico , Neoplasias Cutâneas/patologia , Ácidos Cafeicos/farmacologia , Ácidos Cafeicos/química , Ácidos Cafeicos/uso terapêutico , Apoptose , Fosfatidilinositol 3-Quinases/metabolismoRESUMO
Two fruit fly (Diptera: Tephritidae) species of economic importance: Ceratitis rosa Karsch and Ceratitis quilicii De Meyer, Mwatawala & Virgilio are present in South Africa. The two species were considered as one species prior to 2016, but were subsequently separated. In this study, the distribution and abundance of the two species were quantified in seven provinces in South Africa through trapping with Enriched Ginger Oil as an attractant. Trapping was conducted over three seasons across two years (2020 and 2021): late summer, autumn-winter, and spring-early summer. Host ranges of the two species were investigated by fruit sampling in and outside of trapping sites. Ceratitis quilicii was more widely distributed than C. rosa with the latter being recorded in only three north-eastern provinces. There were geographical limits for both species with no records of them in Northern Cape Province. Catches of C. quilicii were higher in summer with average temperatures varying from 15 to 27°C while for C. rosa, catches remained low and consistent between seasons. Ceratitis quilicii catches decreased at lower rates than those of C. rosa at temperatures below 15°C. The two species were reared from 13 plant species from nine families. Four of these hosts were infested by both C. quilicii and C. rosa in the same province where they occurred. Preferred hosts of the two species belonged to the Myrtaceae family. The characterisation of the distribution, abundance and host ranges of these pests will provide a baseline for pest status determination and implementation of management actions.
RESUMO
Chronic wounds significantly impact the patients' quality of life, creating an urgent interdisciplinary clinical challenge. The development of novel agents capable of accelerating the healing process is essential. Caffeic acid phenethyl ester (CAPE) has demonstrated positive effects on skin regeneration. However, its susceptibility to degradation limits its pharmaceutical application. Chemical modification of the structure improves the pharmacokinetics of this bioactive phenol. Hence, two novel series of CAPE hybrids were designed, synthesized, and investigated as potential skin regenerative agents. To enhance the stability and therapeutic efficacy, a caffeic acid frame was combined with quinolines or isoquinolines by an ester (1a-f) or an amide linkage (2a-f). The effects on cell viability of human gingival fibroblasts (HGFs) and HaCaT cells were evaluated at different concentrations; they are not cytotoxic, and some proved to stimulate cell proliferation. The most promising compounds underwent a wound-healing assay in HGFs and HaCaT at the lowest concentrations. Antimicrobial antioxidant properties were also explored. The chemical and thermal stabilities of the best compounds were assessed. In silico predictions were employed to anticipate skin penetration capabilities. Our findings highlight the therapeutic potential of caffeic acid phenethyl ester (CAPE) derivatives 1a and 1d as skin regenerative agents, being able to stimulate cell proliferation, control bacterial growth, regulate ROS levels, and being thermally and chemically stable. An interesting structure-activity relationship was discussed to suggest a promising multitargeted approach for enhanced wound healing.
RESUMO
Basking sharks (Cetorhinus maximus) seasonally aggregate in coastal surface waters of the North Atlantic, providing opportunities for visual observation. While putative courtship displays have been observed, actual copulation has not been documented. Here we examine video collected by an unmanned aerial vehicle ("drone") of novel behavioral interactions between basking sharks in Cape Cod Bay, Massachusetts in May 2021. The behaviors, including close following and tight concentric circling, are consistent with pre-copulatory behavior observed in other shark species. These observations provide new insights into the pre-copulatory behavior of basking sharks.
RESUMO
Vacuum-Assisted Sorbent Extraction (VASE) is a novel extraction technique that uses vacuum to facilitate the transfer of volatile compounds from the matrix to the sorbent. This technique was explored for extraction of volatiles from cape gooseberry fruit, for both qualitative and quantitative analyses. Selected extraction parameters were tested: sample size, extraction temperature and time, influence of tissue disintegration on release of volatiles, and also addition of Ag+1 ions in the form of AgNO3 to stop enzymatic formation of volatile compounds. For selected conditions (10 g sample, extraction for 30 min. at 40 °C of volatiles from blended fruit) quantitative aspects were explored. Twenty-two compounds of cape gooseberry were tested. The method was characterized with a very good linearity in a range of 10-5000 µg/kg and good reproducibility. The experiments proved the usefulness of VASE in both volatile profiling and quantitative analyses of cape gooseberry and in prospective other fruit.
Assuntos
Frutas , Physalis , Compostos Orgânicos Voláteis , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/isolamento & purificação , Compostos Orgânicos Voláteis/química , Physalis/química , Frutas/química , Vácuo , Reprodutibilidade dos Testes , Extratos Vegetais/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Extração em Fase Sólida/métodosRESUMO
South Africa faces the urgency to comprehensively understand and manage its methane (CH4) emissions. The primary aim of this study is to compare CH4 concentrations between Eastern Cape and Mpumalanga regions dominated by cattle farming and coal mining industries, respectively. CH4 concentration trends were analyzed for the period 2019 to 2023 using satellite data. Trend analysis revealed significant increasing trends in CH4 concentrations in both provinces, supported by Mann-Kendall tests that rejected the null hypothesis of no trend (Eastern Cape: p-value = 8.9018e-08 and Mpumalanga: p-value = 2.4650e-10). The Eastern Cape, a leading cattle farming province, exhibited cyclical patterns and increasing CH4 concentrations, while Mpumalanga, a major coal mining province, displayed similar increasing trends with sharper concentration points. The results show seasonal variations in CH4 concentrations in the Eastern Cape and Mpumalanga provinces. High CH4 concentrations are observed in the northwestern region during the December-January-February (DJF) season, while lower concentrations are observed in the March-April-May (MAM) and June-July-August (JJA) seasons in the Eastern Cape province. In the Mpumalanga province, there is a dominance of high CH4 concentrations in southwestern regions and moderately low concentrations in the northeastern regions, observed consistently across all seasons. The study also showed an increasing CH4 concentration trend from 2019 to 2023 for both provinces. The study highlights the urgent need to address CH4 emissions from both cattle farming and coal mining activities to mitigate environmental impacts and promote sustainable development. Utilizing geographic information system (GIS) and remote sensing technologies, policymakers and stakeholders can identify and address the sources of CH4 emissions more effectively, thereby contributing to environmental conservation and sustainable resource management.
Assuntos
Poluentes Atmosféricos , Monitoramento Ambiental , Metano , Estações do Ano , África do Sul , Metano/análise , Monitoramento Ambiental/métodos , Poluentes Atmosféricos/análise , Animais , Poluição do Ar/estatística & dados numéricos , Bovinos , Minas de CarvãoRESUMO
With the increasing clinical application of dental and orthopedic implants, the problem of peri-implant osteolysis has attracted attention. The inflammatory response and osteoclast differentiation induced by wear particles play an important role in peri-implant bone loss. However, the treatment of peri-implant osteolysis is still lacking. In the present study, we investigated the effect of caffeic acid phenethyl ester (CAPE) on titanium particles induced bone loss in a mouse model. We found that CAPE significantly suppressed titanium particle-induced bone loss in vivo. CAPE treatment decreased ratio of nuclear factor kappa B receptor activator ligand (RANKL)/osteoprotegerin (OPG) and subsequently reduced osteoclastogenesis in the mouse model. In addition, CAPE downregulated the expression and secretion of interleukin-6 (IL-6), interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α) stimulated by titanium particles in vivo. In summary, we conclude that CAPE prevent the titanium particles-induced bone loss.
RESUMO
The iconic Cape buffalo has experienced several documented population declines in recent history. These declines have been largely attributed to the late 19th century rinderpest pandemic. However, the effect of the rinderpest pandemic on their genetic diversity remains contentious, and other factors that have potentially affected this diversity include environmental changes during the Pleistocene, range expansions and recent human activity. Motivated by this, we present analyses of whole genome sequencing data from 59 individuals from across the Cape buffalo range to assess present-day levels of genome-wide genetic diversity and what factors have influenced these levels. We found that the Cape buffalo has high average heterozygosity overall (0.40%), with the two southernmost populations having significantly lower heterozygosity levels (0.33% and 0.29%) on par with that of the domesticated water buffalo (0.29%). Interestingly, we found that these lower levels are probably due to recent inbreeding (average fraction of runs of homozygosity 23.7% and 19.9%) rather than factors further back in time during the Pleistocene. Moreover, detailed investigations of recent demographic history show that events across the past three centuries were the main drivers of the exceptional loss of genetic diversity in the southernmost populations, coincident with the onset of colonialism in the southern extreme of the Cape buffalo range. Hence, our results add to the growing body of studies suggesting that multiple recent human-mediated impacts during the colonial period caused massive losses of large mammal abundance in southern Africa.
Assuntos
Genética Populacional , Peste Bovina , Animais , Humanos , África do Sul , Variação Genética , Búfalos/genética , ColonialismoRESUMO
BACKGROUND AND AIMS: It is unclear how widespread polyploidy is throughout the largest holocentric plant family - the Cyperaceae. Because of the prevalence of chromosomal fusions and fissions, which affect chromosome number but not genome size, it can be impossible to distinguish if individual plants are polyploids in holocentric lineages based on chromosome count data alone. Furthermore, it is unclear how differences in genome size and ploidy levels relate to environmental correlates within holocentric lineages, such as the Cyperaceae. METHODS: We focus our analyses on tribe Schoeneae, and more specifically the southern African clade of Schoenus. We examine broad-scale patterns of genome size evolution in tribe Schoeneae and focus more intensely on determining the prevalence of polyploidy across the southern African Schoenus by inferring ploidy level with the program ChromEvol, as well as interpreting chromosome number and genome size data. We further investigate whether there are relationships between genome size/ploidy level and environmental variables across the nutrient-poor and summer-arid Cape biodiversity hotspot. KEY RESULTS: Our results show a large increase in genome size, but not chromosome number, within Schoenus compared to other species in tribe Schoeneae. Across Schoenus, there is a positive relationship between chromosome number and genome size, and our results suggest that polyploidy is a relatively common process throughout the southern African Schoenus. At the regional scale of the Cape, we show that polyploids are more often associated with drier locations that have more variation in precipitation between dry and wet months, but these results are sensitive to the classification of ploidy level. CONCLUSIONS: Polyploidy is relatively common in the southern African Schoenus, where a positive relationship is observed between chromosome number and genome size. Thus, there may be a high incidence of polyploidy in holocentric plants, whose cell division properties differ from monocentrics.
Assuntos
Cyperaceae , Cyperaceae/genética , Ploidias , Poliploidia , Cromossomos de Plantas , Biodiversidade , Genoma de Planta , FilogeniaRESUMO
BACKGROUND AND AIMS: The prevailing view from the areocladogenesis of molecular phylogenies is that the iconic South African Cape Proteaceae (subfamily Proteoideae) arrived from Australia across the Indian Ocean in the Upper Cretaceous (100â65 million years ago, Ma). Since fossil pollen indicates that the family probably arose in North-West Africa during the early Cretaceous, an alternative view is that it migrated to the Cape from North-Central Africa. The plan therefore was to collate fossil pollen records throughout Africa to determine if they are consistent with an African (para-autochthonous) origin for the Cape Proteaceae, and to seek further support from other paleo-disciplines. METHODS: Palynology (identity, date and location of records), molecular phylogeny and chronogram preparation, biogeography of plate tectonics, and paleo-atmospheric and ocean circulation models. KEY RESULTS: Our collation of the rich assemblage of Proteaceae palynomorphs stretching back to 107 Ma (Triorites africaensis) in North-West Africa showed its progressive overland migration to the Cape by 75â65 Ma. No key palynomorphs recorded in Australia-Antarctica have morphological affinities with African fossils but specific clade assignment of the preMiocene records is not currently possible. The Cape Proteaceae encompass three molecular-based clades (tribes) whose most-recent apparent ancestors are sisters to those in Australia. However, our chronogram shows that the major Adenanthos/Leucadendron-related clade, originating 54â34 Ma, would have 'arrived' too late as species with Proteaceae affinities were already present ~20 My earlier. The Franklandia/Protea-related clade arose 118â81 Ma so its distinctive pollen should have been the foundation for the scores of palynomorphs recorded at 100â80 Ma but it was not. Also, the prevailing winds and ocean currents trended away from South Africa rather than towards, as the 'out-of-Australia' hypothesis requires. Based on the evidence assembled here, we list three points favouring an Australian origin and nine against; four points favouring an Antarctic origin and seven against; and nine points favouring a North-Central African origin and three against. CONCLUSIONS: We conclude that a gradual migration of the Proteaceae from North-Central Africa southeastâsouthâsouthwest to the Cape and surrounds occurred via adaptation and speciation during the period 90â70 Ma. We caution that incorrect conclusions may be drawn from literal interpretations of molecular phylogenies that neglect the fossil record and do not recognize the possible confounding effects of selection under matched environments leading to parallel evolution and extinction of bona fide sister clades.