Essential oil variation of Tagetes minuta in South Africa – A chemometric approach

Tagetes minuta L., generally known as wild marigold and locally as “Kakiebos”, has been used traditionally for medicinal purposes in many countries around the world. South Africa is currently the major producer of Tagetes essential oil which is used in perfumery, cosmetics and aromatherapy. The organoleptic and therapeutic properties of an essential oil are dependent upon the chemical profile of the oil. Tagetes essential oil from India, Egypt and the United Kingdom has been reported to be highly variable. In this study, possible chemotypic variation of South African Tagetes oil was explored. Eighty-three individual plants were collected from twenty-one different localities in South Africa. Essential oils were obtained by hydrodistillation using a Clevenger-type apparatus and the oil yield obtained ranged between 0.38 and 1.52%. The essential oils were analysed by gas chromatography coupled to mass spectrometry with flame ionisation detector (GC–MS‒FID) and the major compounds accounting for >85% of the total composition were identified as: (Z)-β-ocimene (27.9–56.0%), (E)-ocimenone (7.4–37.2%), (Z)-tagetone (1.4–24.9%), dihydrotagetone (n.d.−23.4%), (Z)-ocimenone (4.5–13.9%), limonene (n.d.−6.5%) and (E)-tagetone (n.d.−3.2%). Untargeted analysis of GC–MS data using MarkerLynx^® and hierarchical clustering analysis (HCA) revealed two major chemotypes. Further analysis of the two chemotypes using orthogonal projections to latent structures-discriminant analysis (OPLS-DA) identified (E)-tagetone, dihydrotagetone and (Z)-tagetone as characteristic marker constituents for chemotype 1, while chemotype 2 was characterised by (Z)-β-ocimene, (E)-ocimenone and (Z)-ocimenone.     

Fish and fisheries in hot water: What is happening and how do we adapt?

Rapid climate changes are currently driving substantial reorganizations of marine ecosystems around the world. A key question is how these changes will alter the provision of ecosystem services from the ocean, particularly from fisheries. To answer this question, we need to understand not only the ecological dynamics of marine systems, but also human adaptation and feedbacks between humans and the rest of the natural world. In this review, we outline what we have learned from research primarily in continental shelf ecosystems and fishing communities of North America. Key findings are that marine animals are highly sensitive to warming and are responding quickly to changes in water temperature, and that such changes are often happening faster than similar processes on land. Changes in species distributions and productivity are having substantial impacts on fisheries, including through changing catch compositions and longer distances traveled for fishing trips. Conflicts over access to fisheries have also emerged as species distributions are no longer aligned with regulations or catch allocations. These changes in the coupled natural-human system have reduced the value of ecosystem services from some fisheries and risk doing so even more in the future. Going forward, substantial opportunities for more effective fisheries management and operations, marine conservation, and marine spatial planning are likely possible through greater consideration of climate information over time-scales from years to decades.     

Activation of the PDGF β Receptor by a Persistent Artificial Signal Peptide

Most eukaryotic transmembrane and secreted proteins contain N-terminal signal peptides that mediate insertion of the nascent translation products into the membrane of the endoplasmic reticulum. After membrane insertion, signal peptides typically are cleaved from the mature protein and degraded. Here, we tested whether a small hydrophobic protein selected for growth promoting activity in mammalian cells retained transforming activity while also acting as a signal peptide. We replaced the signal peptide of the PDGF β receptor (PDGFβR) with a previously described 29-residue artificial transmembrane protein named 9C3 that can activate the PDGFβR in trans. We showed that a modified version of 9C3 at the N-terminus of the PDGFβR can function as a signal peptide, as assessed by its ability to support high level expression, glycosylation, and cell surface localization of the PDGFβR. The 9C3 signal peptide retains its ability to interact with the transmembrane domain of the PDGFβR and cause receptor activation and cell proliferation. Cleavage of the 9C3 signal peptide from the mature receptor is not required for these activities. However, signal peptide cleavage does occur in some molecules, and the cleaved signal peptide can persist in cells and activate a co-expressed PDGFβR in trans. Our finding that a hydrophobic sequence can display signal peptide and transforming activity suggest that some naturally occurring signal peptides may also display additional biological activities by interacting with the transmembrane domains of target proteins.     

Sensing cellular biochemistry with fluorescent chemical–genetic hybrids

Fluorescent biosensors are powerful tools for the detection of biochemical events inside cells with high spatiotemporal resolution. Biosensors based on fluorescent proteins often suffer from issues with photostability and brightness. On the other hand, hybrid, chemical–genetic systems present unique opportunities to combine the strengths of synthetic, organic chemistry with biological macromolecules to generate exquisitely tailored semisynthetic sensors.     

Preliminary fabrication and characterization of electron beam melted Ti–6Al–4V customized dental implant

The current study was aimed to fabricate customized root form dental implant using additive manufacturing technique for the replacement of missing teeth. The root form dental implant was designed using Geomagic™ and Magics™, the designed implant was directly manufactured by layering technique using ARCAM A2™ electron beam melting system by employing medical grade Ti–6Al–4V alloy powder. Furthermore, the fabricated implant was characterized in terms of certain clinically important parameters such as surface microstructure, surface topography, chemical purity and internal porosity. Results confirmed that, fabrication of customized dental implants using additive rapid manufacturing technology offers an attractive method to produce extremely pure form of customized titanium dental implants, the rough and porous surface texture obtained is expected to provide better initial implant stabilization and superior osseointegration.     

Identifying novel targets in renal cell carcinoma: Design and synthesis of affinity chromatography reagents

Two novel scaffolds, 4-pyridylanilinothiazoles (PAT) and 3-pyridylphenylsulfonyl benzamides (PPB), previously identified as selective cytotoxins for von Hippel–Lindau-deficient Renal Carcinoma cells, were used as templates to prepare affinity chromatography reagents to aid the identification of the molecular targets of these two classes. Structure–activity data and computational models were used to predict possible points of attachment for linker chains. In the PAT class, Click coupling of long chain azides with 2- and 3-pyridylanilinothiazoleacetylenes gave triazole-linked pyridylanilinothiazoles which did not retain the VHL-dependent selectivity of parent analogues. For the PPB class, Sonagashira coupling of 4-iodo-(3-pyridylphenylsulfonyl)benzamide with a propargyl hexaethylene glycol carbamate gave an acetylene which was reduced to the corresponding alkyl 3-pyridylphenylsulfonylbenzamide. This reagent retained the VHL-dependent selectivity of the parent analogues and was successfully utilized as an affinity reagent.     

Features and influencing factors of carbon emissions indicators in the perspective of residential consumption: Evidence from Beijing,China

This research establishes a residential indirect carbon emissions model through input–output structure decomposition analysis (IO-SDA) and LMDI, analyses the influencing factors affecting urban and rural residential carbon emissions indicators in Beijing through input–output tables from 2000 to 2010, and calculates the direct carbon emissions from residential consumption. As the results suggest, the total carbon emissions from residential consumption in Beijing showed volatility. Growing rural and urban differences in direct emissions, and for indirect emissions, mean that urban greatly exceeds rural in this regard. Rising per capita GDP and population, as well as intermediate demand and sectoral emissions intensity change induce growth in indirect emissions in both urban and rural settings: of which, per capita GDP contributes the most. Declining energy intensity contributes the most to emission reductions, followed by residential consumption rates, the rural to urban consumption ratio and consumption structure effects are much smaller.     

Root responses to legume plants integrate information on nitrogen availability and neighbour identity

Rhizobial symbiosis is known to increase the nitrogen availability in the rhizosphere of legumes. Therefore, it has been hypothesized that other plants’ roots should forage towards legume neighbours, but avoid non-legume neighbours. Yet, root distribution responding to legume plants as opposed to non-legumes has not yet been rigorously tested and might well be subject to integration of multiple environmental cues.In this study, wedevised an outdoor mesocosm experiment to examine root distributions of the two plant species Pilosella officinarum and Arenaria serpyllifolia in a two-factorial design. While one factor was ‘neighbour identity’, where plants were exposed to different legume or non-legume neighbours, the other factor was ‘nitrogen supply’. In the latter the nutrient-poor soil was supplemented with either nitrogen-free or with nitrogen-containing fertilizer.Unexpectedly, of all treatments that included a legume neighbour (eight different species or factor combinations), we found merely one case of root aggregation towards a legume neighbour (P. officinarum towards Medicago minima under nitrogen-fertilized conditions). In this very treatment, also P. officinarum root–shoot allocation was strongly increased, indicating that neighbour recognition is coupled with a contesting strategy.Considering the various response modes of the tested species towards the different legume and non-legume neighbours, we can conclude that roots integrate information on neighbour identity and resource availability in a complex manner. Especially the integration of neighbour identity in root decisions must be a vital aptitude for plants to cope with their complex biotic and abiotic environment in the field.     

Structure–activity relationships (SAR) and structure–kinetic relationships (SKR) of bicyclic heteroaromatic acetic acids as potent CRTh2 antagonists III: The role of a hydrogen-bond acceptor in long receptor residence times

The correct positioning and orientation of an hydrogen bond acceptor (HBA) in the tail portion of the biaryl series of CRTh2 antagonists is a requirement for long receptor residence time. The HBA in combination with a small steric substituent in the core section (R^core ≠ H) gives access to compounds with dissociation half-lives of ⩾24 h.     

Cardiorenal fibrosis and dysfunction in aging: Imbalance in mediators and regulators of collagen

Cardiorenal fibrosis is a biological process that increases with age and contributes to dysfunction of the heart and kidney. While numerous circulating and tissue hormones, cytokines and enzymes have been identified in the development of cardiorenal fibrosis, several reports have suggested that the anti-fibrotic natriuretic peptide system (NPS), pro-fibrotic renin–angiotensin–aldosterone system (RAAS), transforming growth factor-beta 1 (TGF-β1), matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) are fundamental regulators and mediators of this process. However, the simultaneous assessment of these components in the development of age-mediated cardiorenal fibrotic remodeling is not completely understood. Thus, we assessed cardiorenal structure and function, the circulating NPS and RAAS and the cardiorenal tissue gene expression of collagen (Col) I, Col III, TGF-β1, MMP-9 and TIMP-1 in 2 and 20 month old Fischer rats. Our studies determined that aging was characterized by an increase in cardiorenal fibrosis that was accompanied with cardiorenal dysfunction. These alterations were associated with lower circulating atrial and C-type natriuretic peptides and higher angiotensin II and aldosterone levels in the aged rats. Moreover, we observed a decrease in Col I and III and an increase in TIMP- mRNA expressions in the aged heart and kidney, while TGF-β1 expression increased and MMP-9 decreased only in the aged kidney. We conclude that the age-mediated alterations in these fibrotic regulator and mediator profiles favors collagen accumulation due to an imbalance between the NPS and RAAS as well as a decline in the degradative pathway, thus suggesting a therapeutic opportunity to target these components.