Modulation of siderophore production by Pseudomonas fluorescens through the manipulation of the culture medium composition

Pseudomonas fluorescens has the ability to produce the siderophore pyoverdine, a biotechnologically significant iron chelator, which has a wide range of potential applications, such as in agriculture (iron fertilizers) and medicine (development of antibiotics). The present work aimed to evaluate the influence of culture medium composition on the production of siderophores by P. fluorescens DSM 50090, an industrial relevant strain. It was found that the bacterium grown in minimal medium succinate (MMS) had a higher siderophore production than in King B medium. The replacement of succinate by glycerol or dextrose, in minimal medium, originated lower siderophore production. The increase of succinate concentration, the addition of amino acids or the reduction of phosphate in the culture medium did not improve siderophore production by P. fluorescens. The results obtained strongly suggest that (i) MMS is more appropriate than King B for large-scale production of siderophores; (ii) the modification of the culture medium composition, particularly the type of carbon source, influences the level of siderophore secreted; (iii) the production of siderophore by P. fluorescens seems to be a tightly regulated process; once a maximum siderophore concentration has been reached in the culture medium, the bacterium seems to be unable to produce more compound.João M. Vindeirinho received the grant from the project PTDC-AGR-TEC/0458/2014—POCI-01-0145-FEDER-016681. This work is financed by the FEDER funds through the Operational Competitiveness Factors Program—COMPETE and by national funds through FCT—Foundation for Science and Technology within the scope of the project PTDC-AGR-TEC/0458/2014—POCI-01-0145-FEDER-016681.info:eu-repo/semantics/publishedVersio

A practical implication of the Astolfo Effect: bias in AI generated images

Source at https://jgeekstudies.org/.The year of 2022 saw a huge advance in AI technology, especially Large Language Models, or LLMs. This culminated in the release of Chat GPT, an AI Chatbot assistant that, as of the time of this writing, is wowing the public with its uncanny performance. However, chatbots are not the only application of LLMs. One such application is the artificial generation of images. Although such idea is not a novel one (it dates back to the 1970s; Elgammal, 2022), the advancements on large language models allowed a new breakthrough in what these methods are able to achieve. A non-obvious application of such models is as a “probe” for bias in its learning set. Since these models are trained on public datasets collected from the Internet, they tend to reflect the inherent biases present in human generated content. As such, we see the advent of AI generated image as an opportunity to further test the ‘Astolfo Effect’ hypothesis, as first outlined by Tomotani & Salvador (2021)

Retinal Vessel Segmentation Using the 2-D Morlet Wavelet and Supervised Classification

We present a method for automated segmentation of the vasculature in retinal images. The method produces segmentations by classifying each image pixel as vessel or non-vessel, based on the pixel's feature vector. Feature vectors are composed of the pixel's intensity and continuous two-dimensional Morlet wavelet transform responses taken at multiple scales. The Morlet wavelet is capable of tuning to specific frequencies, thus allowing noise filtering and vessel enhancement in a single step. We use a Bayesian classifier with class-conditional probability density functions (likelihoods) described as Gaussian mixtures, yielding a fast classification, while being able to model complex decision surfaces and compare its performance with the linear minimum squared error classifier. The probability distributions are estimated based on a training set of labeled pixels obtained from manual segmentations. The method's performance is evaluated on publicly available DRIVE and STARE databases of manually labeled non-mydriatic images. On the DRIVE database, it achieves an area under the receiver operating characteristic (ROC) curve of 0.9598, being slightly superior than that presented by the method of Staal et al.Comment: 9 pages, 7 figures and 1 table. Accepted for publication in IEEE Trans Med Imag; added copyright notic

Incorporation of dual-stimuli responsive microgels in nanofibrous membranes for cancer treatment by magnetic hyperthermia

Funding Information: This work is funded by FEDER funds through the COMPETE 2020 Program and National Funds through FCT?Portuguese Foundation for Science and Technology under the project POCI?01-0145-FEDER-007688 (Reference UID/CTM/50025) and PTDC/CTMCTM/30623/2017 (DREaMM).The delivery of multiple anti-cancer agents holds great promise for better treatments. The present work focuses on developing multifunctional materials for simultaneous and local combi-natory treatment: Chemotherapy and hyperthermia. We first produced hybrid microgels (MG), synthesized by surfactant-free emulsion polymerization, consisting of Poly (N-isopropyl acrylamide) (PNIPAAm), chitosan (40 wt.%), and iron oxide nanoparticles (NPs) (5 wt.%) as the inorganic compo-nent. PNIPAAm MGs with a hydrodynamic diameter of about 1 µm (in their swollen state) were successfully synthesized. With the incorporation of chitosan and NPs in PNIPAAm MG, a decrease in MG diameter and swelling capacity was observed, without affecting their thermosensitivity. We then sought to produce biocompatible and mechanically robust membranes containing these dual-responsive MG. To achieve this, MG were incorporated in poly (vinyl pyrrolidone) (PVP) fibers through colloidal electrospinning. The presence of NPs in MG decreases the membrane swelling ratio from 10 to values between 6 and 7, and increases the material stiffness, raising its Young modulus from 20 to 35 MPa. Furthermore, magnetic hyperthermia assay shows that PVP-MG-NP composites perform better than any other formulation, with a temperature variation of about 1◦C. The present work demonstrates the potential of using multifunctional colloidal membranes for magnetic hyperthermia and may in the future be used as an alternative treatment for cancer.publishersversionpublishe

Diversity of Lepidoptera recorded in a forest nursery of Nordeste county on São Miguel Island (Azores)

The diversity of moth species (Insecta, Lepidoptera) recorded in the forest nursery of Nordeste county on São Miguel island (Azores) is given. Adults were sampled between March and December 2019 using three methods: (i) light trap to caught Noctuidae species, (ii) open-sided delta trap baited with a synthetic female sex pheromone lure to attract Epiphyas postvittana males and (iii) entomological net to identify microlepidopteran moths. A total of 10160 adults belonging to 33 lepidopteran species were recorded and listed by families, including: Argyresthiidae 1 (3%), Crambidae 4 (12%), Erebidae 1 (3%), Geometridae 5 (15%), Noctuidae 18 (55%), Sphingidae 1 (3%), Tineidae 1 (3%), and Tortricidae 2 (6%). The families Noctuidae, Geometridae and Crambidae were the most diverse. Those with the highest abundance of adults was the Noctuidae family followed by the Crambidae, Trotricidae and Tineidae. The number of caught adults was consistently higher during spring and summer, decreasing sharply in late fall. For 14 species caught in the light trap the adult sex ratio was favorable to females, except for Xestia c-nigrum which was favorable to males. An analysis of the colonization status, feeding and primary hosts of these endemic, native or exotic moth species suggests that plants reared in forest nurseries, being attacked by such insects, facilitates our understanding of the diversity of lepidopterans that establish in Laurel Forest environments and to what extent there is a need to monitor and control them mainly with biological control agents.Regional Founds, through Official Forestry Services from Regional Government of the Azores, within the research project MoCIL “Monitorização e Controlo Integrado de Lepidópteros em Viveiros Florestais (Nordeste e Furnas) na ilha de São Miguel - Açores” FCT – Fundação para a Ciência e a Tecnologia, I.P., under the project UIDP/05292/2020 and UIDB/05292/2020. AZORESBIOPORTAL–PORBIOTA (ACORES-01-0145-FEDER-000072) (2019-2022).info:eu-repo/semantics/publishedVersio

Diversity of Lepidoptera (Insecta) recorded in a forest nursery of Nordeste County on São Miguel Island (Azores)

BACKGROUND: The diversity of moth species (Insecta, Lepidoptera) recorded in the forest nursery of Nordeste County on São Miguel Island (Azores) is given. Adults were sampled between March and December 2019 using three methods: (i) light trap to catch Noctuidae species, (ii) open-sided delta trap baited with a synthetic female sex pheromone lure to attract Epiphyas postvittana (Walker) males and (iii) entomological net to collect microlepidopteran moths. This contribution focuses mainly on the diversity of moths present in one forest nursery of Nordeste County of São Miguel Island (Azores), especially on the species associated with endemic and native plant species. It also contributes to better plan strategies for integrated protection and conservation measures, since nurseries host a great diversity of plants from the Laurel Forest, which may attract many lepidopteran species. NEW INFORMATION: A total of 10160 adults belonging to 33 lepidopteran species were recorded and listed by families, including: Argyresthiidae, one species (3%), Crambidae, four species (12%), Erebidae, one species (3%), Geometridae, five species (15%), Noctuidae, 18 species (55%), Sphingidae, one species (3%), Tineidae, one species (3%) and Tortricidae, two species (6%). The families Noctuidae, Geometridae and Crambidae were the most diverse. Those with the highest abundance of adults were the Noctuidae family, followed by the Geometridae, Crambidae, Tortricidae and Tineidae. The number of caught adults was consistently higher during spring and summer, decreasing sharply in late autumn. For 13 species caught in the light trap, the adult sex ratio was favourable to females. An analysis of the colonisation status, feeding and primary hosts of these endemic, native or exotic moth species contributes to our understanding of the factors that may lead to their establishment in Laurel Forest environments and to what extent there is a need to monitor and control them mainly with biological control agents.This research was supported by the Official Forestry Services from the Regional Government of the Azores, through the research project MoCIL "Monitorizacao e Controlo Integrado de Lepidopteros em Viveiros Florestais (Nordeste e Furnas) na ilha de Sao Miguel - Acores", in direct collaboration with the Forestry Engineers Carina Nobrega and Catarina Quintela, by FCT - Fundacao para a Ciencia e a Tecnologia, I.P., under the project UIDP/05292/2020 and UIDB/05292/2020 and by AZORESBIOPORTAL PORBIOTA (ACORES-01-0145-FEDER-000072) (2019-2022).info:eu-repo/semantics/publishedVersio

In reply

http://dx.doi.org/10.1197/j.aem.2006.02.00

Recent emission channeling studies in wide band gap semiconductors

We present results of recent emission channeling experiments on the lattice location of implanted Fe and rare earths in wurtzite GaN and ZnO. In both cases the majority of implanted atoms are found on substitutional cation sites. The root mean square displacements from the ideal substitutional Ga and Zn sites are given and the stability of the Fe and rare earth lattice location against thermal annealing is discussed

Study and valorisation of wastewaters generated in the production of bacterial nanocellulose

[Excerpt] The use of low-cost residues from the agro-food industries in the formulation of fermentation culture media is often claimed to represent a strategy to reduce the production cost Bacterial NanoCellulose (BNC). However, the impact of such culture media, e.g. made of molasse and corn steep liquor, on the organic load of the wastewaters generated in this process has never been assessed. This work aims to characterize the wastewaters resulting from the fermentation of BNC using different culture media, under static culture, as well as their biochemical methane potential (BMP) and anaerobic biodegradability. Anaerobic digestion (AD) is one of the most promising treatments for industrial wastewaters with high organic loads since, beyond removal of the organic matter, it generates energy in form of biogas. Two wastewaters streams were analysed: i) the one collected from the culture medium after fermentation (WaF); ii) the one that, in addition to the previous, includes the BNC washing wastewaters (WaW). The performance of an upflow anaerobic sludge blanket reactor (UASB) for the treatment of the later (WaW) was also evaluated. [...]info:eu-repo/semantics/publishedVersio

Continental-scale surface reflectance product from CBERS-4 MUX data: Assessment of atmospheric correction method using coincident Landsat observations

A practical atmospheric correction algorithm, called Coupled Moderate Products for Atmospheric Correction (CMPAC), was developed and implemented for the Multispectral Camera (MUX) on-board the China-Brazil Earth Resources Satellite (CBERS-4). This algorithm uses a scene-based processing and sliding window technique to derive MUX surface reflectance (SR) at continental scale. Unlike other optical sensors, MUX instrument imposes constraints for atmospheric correction due to the absence of spectral bands for aerosol estimation from imagery itself. To overcome this limitation, the proposed algorithm performs a further processing of atmospheric products from Moderate Resolution Imaging Spectroradiometer (MODIS) and Visible Infrared Imaging Radiometer Suite (VIIRS) sensors as input parameters for radiative transfer calculations. The success of CMPAC algorithm was fully assessed and confirmed by comparison of MUX SR data with the Landsat-8 OLI Level-2 and Aerosol Robotic Network (AERONET)-derived SR products. The spectral adjustment was performed to compensate for the differences of relative spectral response between MUX and OLI sensors. The results show that MUX SR values are fairly similar to operational Landsat-8 SR products (mean difference \u3c 0.0062, expressed in reflectance). There is a slight underestimation of MUX SR compared to OLI product (except the NIR band), but the error metrics are typically low and scattered points are around the line 1:1. These results suggest the potential of combining these datasets (MUX and OLI) for quantitative studies. Further, the robust agreement of MUX and AERONET-derived SR values emphasizes the quality of moderate atmospheric products as input parameters in this application, with root-mean-square deviation lower than 0.0047. These findings confirm that (i) CMPAC is a suitable tool for estimating surface reflectance of CBERS MUX data, and (ii) ancillary products support the application of atmospheric correction by filling the gap of atmospheric information. The uncertainties of atmospheric products, negligence of the bidirectional effects, and two aerosol models were also identified as a limitation. Finally, this study presents a framework basis for atmospheric correction of CBERS-4 MUX images. The utility of CBERS data comes from its use, and this new product enables the quantitative remote sensing for land monitoring and environmental assessment at 20 m spatial resolution