Search Results (18)

The taxonomic complexity of Phoenix palms in the Canary Islands, where multiple morphotypes representing at least four taxa currently exist, presents significant challenges for archaeobotanical identification. We developed a Bayesian probabilistic framework to identify archaeological Phoenix seeds within the context of genus-wide morphological diversity. Our analysis incorporated thousands of specimens including modern reference collections, archaeological materials from pre-Hispanic sites in Gran Canaria and La Gomera (3–16th centuries CE), and fossil remains. We recorded quantitative measurements and qualitative characteristics for each specimen. To understand taphonomic effects, we conducted experimental carbonization of modern P. canariensis seeds and documented the resulting morphological alterations. We performed a hierarchical cluster analysis using Ward’s minimum variance method and calculated taxonomic assignment probabilities for archaeological specimens using Bayesian inference, where likelihood was derived from taxon proportions within assigned clusters. The results indicated a high probability (0.69–1.00) that the archaeological specimens belong to P. canariensis var. canariensis, with no evidence for P. dactylifera presence. These findings provide critical insights into pre-Hispanic exploitation of Phoenix palms, particularly the endemic P. canariensis, which served as a vital resource, providing food, fiber, and construction materials. Our methodological approach offers a robust framework for addressing taxonomic uncertainty in archaeobotanical research while enhancing understanding of historical palm biogeography and resource use patterns in the Canary Islands. Full article

We study fixed-point theorems of contractive mappings in b-metric space, cone b-metric space, and the newly introduced extended b-metric space. To generalize an existence and uniqueness result for the so-called ${\mathsf{\Phi }}_s$ functions in the b-metric space to the extended b-metric space and the cone b-metric space, we introduce the class of ${\mathsf{\Phi }}_M$ functions and apply the Hölder continuous condition in the extended b-metric space. The obtained results are applied to prove the existence and uniqueness of solutions and positive solutions for nonlinear integral equations and fractional boundary value problems. Examples and numerical simulation are given to illustrate the applications. Full article

Introduction; to the best of the authors knowledge, no past research has established how illness narrative master plots are expressed initially and then if and how they change longitudinally following musculoskeletal trauma. The aim of the present research was to consider how specific master plots were expressed, interact, and change across time following musculoskeletal trauma. Methods: A narrative analysis was undertaken that included individuals who had experienced a musculoskeletal traumatic injury. Individuals were included if they were an inpatient within 4 weeks of the first interview, had mental capacity to participate, and were able to communicate in English. Three interviews were undertaken (within 4 weeks of injury, then at 6- and 12-months post-injury). A 5-stage categorical form—type narrative analysis was performed. Results: Twelve individuals (49.9 ± 17.5 years; 7 male, 5 female) completed interviews at three time points following the trauma event (<4 weeks, 6 months, and 12 months). Three main narrative master plots appeared to work together to facilitate a positive accommodation of the trauma event into the individual’s life. These included the resumption narrative, the activity narrative, and the quest narrative. Finally, less often regressive narratives were identified, although these narratives were, at times, actively avoided. Discussion: The current results provide important consideration for how narratives are used within clinical practice, in particular the value of how these three narratives could be accessed and promoted. Full article

The group of nontuberculous mycobacteria (NTM) includes about 200 mycobacteria that are widespread in the natural environment as free-living saprophytic bacteria, commensals or symbionts. NTM, also referred to as atypical mycobacteria, are mostly apathogenic; nowadays, they are increasingly important environmental opportunistic pathogens. This study continues the work of previous studies which investigated the individual and synergistic effect of different essential oils (EOs) on NTM. The aim was to investigate the effect of the interaction of the common juniper (Juniperus communis) EO and the antimicrobials, amikacin, clarithromycin and rifampicin, against Mycobacterium avium and M. intracellulare using the checkerboard synergy method in an enriched Middlebrook 7H9 broth. Morphological changes of treated NTM cells were observed with a transmission electron microscope. The most synergistic combinations were found at subinhibitory concentrations of the common juniper EO and rifampicin against both tested NTM and this EO and clarithromycin against M. avium. A slightly smaller number of synergistic effects on both NTM were found using a combination of this EO and amikacin. Combinations of clarithromycin and the common juniper EO showed no synergism against M. intracellulare. The exposure of both NTM to synergistic combinations of this EO and antimicrobials caused significant morphological changes in mycobacterial cells. Synergism with the combined use of EOs and antimicrobials allows the use of low effective concentrations via the sustained antimicrobial effect of the tested substances, but with potentially reduced toxicity. Full article

It is common practice to model the input–output behavior of a single-loop feedback circuit using the two parameters, A and β. Such an approach was first proposed by Black to explain the advantages and disadvantages of negative feedback. Extensive theories of system behavior (e.g., stability, impedance control) have since been developed by mathematicians and/or control engineers centered around these two parameters. Circuit engineers rely on these insights to optimize the dynamic behavior of their circuits. Unfortunately, no method exists for uniquely identifying A or β in terms of the components of the circuit. Rather, indirect methods, such as the injection method of Middlebrook or the break-the-loop approach proposed by Rosenstark, compute the return ratio RR of the feedback loop and inferred the parameters A and β. While one often assumes that the zeros of (1 + RR) are equal to the zeros of (1 + A × β), i.e., the closed-loop poles are equivalent, this is not true in general. It is the objective of this paper to present an exact method to uniquely identify each feedback parameter, A or β, in terms of the circuit components. Further, this paper will identify the circuit conditions for which the product of A × β leads to the correct closed-loop poles. Full article

Nontuberculous mycobacteria (NTM) are common in the environment and certain species can cause serious infections. Improved environmental surveillance methods are needed to combat the increased incidence of NTM disease. Recently, two methods were developed to improve NTM detection. The MYChrOme™ Culture Plate (patent-pending, Phigenics, LLC, Reno, NV, USA) is the first chromogenic medium for rapid-growing NTM detection in water samples. NTM Elite agar (Biomerieux, Marcy-l’Étoile, France), was developed for rapid-growing NTM detection in clinical samples. Fifty water samples (25 potable and 25 non-potable) with three technical replicates were analyzed by each method and Middlebrook 7H11 selective medium (7H11S) (ASTM E2563-07 method modified for water). The MYChrOme method was overall equivalent to or better than 7H11S medium and NTM Elite agar for the detection of rapid-growing NTM in potable water. All three methods detected similar amounts of NTM in non-potable water samples. The chromogenic property of MYChrOme allowed NTM colonies to be quickly identified and differentiated from other bacteria. Additional analysis is required for colony confirmation on 7H11S medium and NTM Elite agar. The use of innovative environmental NTM diagnostics, in addition to proper water management, can greatly reduce the risk of NTM disease. Full article

Wild animals are considered reservoirs, contributing to the transmission of emerging zoonotic diseases such as tuberculosis (TB). A cross-sectional study was conducted by opportunistic sampling from fresh carcasses of free-ranging wild boar (n = 30), and free-ranging wild macaques (n = 42). Stained smears from these tissues were tested for acid-fast bacilli (AFB) with Ziehl–Neelsen staining. Mycobacterial culture was conducted using Lowenstein–Jensen media and Middlebrook 7H11 agar media. Polymerase chain reaction (PCR) was performed through the detection of the 16S rRNA gene, with multiple sets of primers for the detection of Mycobacterium tuberculosis complex (MTBC) and Mycobacterium avium complex (MAC). In wild boars, 30% (9/30; 95% Confidence Interval: 16.7–47.9%) of examined samples showed gross tuberculosis-like lesions (TBLLs). Multiple nodular lesions that were necrotic/miliary with cavitation were found in the submandibular lymph nodes, tonsils, lungs, kidney and liver, while single nodular lesions were found in the mediastinal lymph nodes, spleen and mesenteric lymph nodes. Conventional PCR on the submandibular lymphoid tissues of wild boar (nine samples with TBLLs and three non-TBLL samples) showed that 75% (9/12) were positive for Mycobacterium bovis (95% CI: 46.8–91.1), and 91% (CI: 64.6–98.5) were positive for Mycobacterium avium. For macaques, 33.3% (10/30) were positive for M. avium (95% CI: 19.2–51.2) but negative for MTBC. Full article

SEO100c, an EO-polymer, has been reported of having an r₃₃ in excess of 100 pm/V. Experimental poling research was performed on rib waveguide modulator for device design and development. Reported is the determination of the impact that temperature and voltage have on the poling of a SEO100c waveguide device in order to maximize the r₃₃ while avoiding damage to the device structure ensuring high yield in manufacture. The poling process is shown to have a nonlinear relationship between r₃₃ and poling field aiding in the selection of achievable poling voltages for required r₃₃ values. Device thermal stability is quantified and reported for the complete poling process and the impacts upon r₃₃. Investigation into the possible relaxation of device r₃₃ is measured over an extended period demonstrating desirable use within deployable devices. Full article

Sustainable energy, such as sunlight and wind energy, that comes from sources that do not need to be replenished has become important. Accordingly, the importance of the design and stable management of DC microgrids is also increasing. From this point of view, this paper analyzes the interaction between source and load converters constituting the DC microgrid using the derived mathematical input and output impedances models. This paper proposes a stability improvement method using the analyzed result. The method focuses on the presence or absence of input and output impedance overlap using Middlebrook’s stability criteria. To verify validity of the proposed method, a case study with three damping methods is conducted: (1) RC parallel damping with PR controller, (2) RL parallel damping with PR controller, and (3) RL series damping with PR controller. Additionally, the frequency domain characteristics and the Nyquist stability are analyzed using MATLAB, and simulation verification is conducted using PSIM. Through the analysis and simulation results, we confirm that the stability of the DC microgrid can be improved by applying the proposed method. The passive damping method analyzed in this paper is applied to an installed power converter, where it is possible to ensure the stability of the DC microgrid. Full article

Mycobacterium avium subspecies paratuberculosis (MAP) are detectable viable in milk and other dairy products. The molecular mechanisms allowing the adaptation of MAP in these products are still poorly understood. To obtain information about respective adaptation of MAP in milk, we differentially analyzed the proteomes of MAP cultivated for 48 h in either milk at 37 °C or 4 °C or Middlebrook 7H9 broth as a control. From a total of 2197 MAP proteins identified, 242 proteins were at least fivefold higher in abundance in milk. MAP responded to the nutritional shortage in milk with upregulation of 32% of proteins with function in metabolism and 17% in fatty acid metabolism/synthesis. Additionally, MAP upregulated clusters of 19% proteins with roles in stress responses and immune evasion, 19% in transcription/translation, and 13% in bacterial cell wall synthesis. Dut, MmpL4_1, and RecA were only detected in MAP incubated in milk, pointing to very important roles of these proteins for MAP coping with a stressful environment. Dut is essential and plays an exclusive role for growth, MmpL4_1 for virulence through secretion of specific lipids, and RecA for SOS response of mycobacteria. Further, 35 candidates with stable expression in all conditions were detected, which could serve as targets for detection. Data are available via ProteomeXchange with identifier PXD027444. Full article

Feeding cereal grain to cattle is common practice for optimal beef and milk production. High concentrations of starch and other soluble carbohydrates may cause acidosis. Information on the effect of processing on starch and protein degradability in the rumen are scarce. This study was to determine the ruminal degradation patterns of common grains and the effect of steam pelleting on starch and crude protein (CP) degradability in the rumen. The ruminal degradation pattern of dry matter (DM), starch, and CP of ground and pelleted sorghum, barley, wheat, and samples along with ground oats and triticale were determined using the in situ nylon bags method. Cereals were incubated for 0, 2, 4, 6, 8, 16, 32, and 60 h, and the fast and slowly degradable fraction, the effective degradation rate, and effective degradability (ED) of DM, starch, and CP were calculated. The starch ED of ground and pelleted sorghum, barley, and two wheat samples were 57.3, 93.6, 95.2, and 97.2%; and 61.5, 93.8, 93.8, and 95.6%, and their crude protein ED was 54.8, 82.3, 83.3, 82.6% and 51.9, 79.2, 81.8, and 78.1% respectively. The starch ED of ground oat and triticale were 98.3 and 94.7%, and that of CP were 93.7 and 75.2%, respectively. The degradability of sorghum was significantly lower than that of the other grains. Pelleting increased the fast-degradable DM and starch faction of sorghum and tended to improve its DM degradability (p = 0.081). Pelleting significantly reduced the fast-degradable fraction of DM and starch of wheat samples and numerically reduced its degradability. Full article

Mycobacterium chimaera is an emerging pathogen associated with endocarditis and vasculitis following cardiac surgery. Although it can take up to 6–8 weeks to culture on selective solid media, culture-based detection remains the gold standard for diagnosis, so more rapid methods are urgently needed. For the present study, we processed environmental M. chimaera infected simulates at volumes defined in international guidelines. Each preparation underwent real-time PCR; inoculates were placed in a VersaTREK™ automated microbial detection system and onto selective Middlebrook 7H11 agar plates. The validation tests showed that real-time PCR detected DNA up to a concentration of 10 ng/µL. A comparison of the isolation tests showed that the PCR method detected DNA in a dilution of ×10² CFU/mL in the bacterial suspensions, whereas the limit of detection in the VersaTREK™ was <10 CFU/mL. Within less than 3 days, the VersaTREK™ detected an initial bacterial load of 100 CFU. The detection limit did not seem to be influenced by NaOH decontamination or the initial water sample volume; analytical sensitivity was 1.5 × 10² CFU/mL; positivity was determined in under 15 days. VersaTREK™ can expedite mycobacterial growth in a culture. When combined with PCR, it can increase the overall recovery of mycobacteria in environmental samples, making it potentially applicable for microbial control in the hospital setting and also in environments with low levels of contamination by viable mycobacteria. Full article

Twenty to thirty percent of the septating mycobacterial cells of the mid-log phase population showed highly deviated asymmetric constriction during division (ACD), while the remaining underwent symmetric constriction during division (SCD). The ACD produced short-sized cells (SCs) and normal/long-sized cells (NCs) as the sister–daughter cells, but with significant differential susceptibility to antibiotic/oxidative/nitrite stress. Here we report that, at 0.2% glycerol, formulated in the Middlebrook 7H9 medium, a significantly high proportion of the cells were divided by SCD. When the glycerol concentration decreased to 0.1% due to cell-growth/division, the ACD proportion gradually increased until the ACD:SCD ratio reached ~50:50. With further decrease in the glycerol levels, the SCD proportion increased with concomitant decrease in the ACD proportion. Maintenance of glycerol at 0.1%, through replenishment, held the ACD:SCD proportion at ~50:50. Transfer of the cells from one culture with a specific glycerol level to the supernatant from another culture, with a different glycerol level, made the cells change the ACD:SCD proportion to that of the culture from which the supernatant was taken. RT-qPCR data showed the possibility of diadenosine tetraphosphate phosphorylase (MSMEG_2932), phosphatidylinositol synthase (MSMEG_2933), and a Nudix family hydrolase (MSMEG_2936) involved in the ACD:SCD proportion-change in response to glycerol levels. We also discussed its physiological significance. Full article

Mycobacterium bovis Bacillus Calmette–Guérin (M. bovis BCG) was generated over a century ago for protection against Mycobacterium tuberculosis (Mtb) and is one the oldest vaccines still in use. The BCG vaccine is currently produced using a pellicle growth method, which is a complex and lengthy process that has been challenging to standardise. Fermentation for BCG vaccine production would reduce the complexity associated with pellicle growth and increase batch to batch reproducibility. This more standardised growth lends itself to quantification of the total number of bacilli in the BCG vaccine by alternative approaches, such as flow cytometry, which can also provide information about the metabolic status of the bacterial population. The aim of the work reported here was to determine which batch fermentation conditions and storage conditions give the most favourable outcomes in terms of the yield and stability of live M. bovis BCG Danish bacilli. We compared different media and assessed growth over time in culture, using total viable counts, total bacterial counts, and turbidity throughout culture. We applied fluorescent viability dyes and flow cytometry to measure real-time within-culture viability. Culture samples were stored in different cryoprotectants at different temperatures to assess the effect of these combined conditions on bacterial titres. Roisin’s minimal medium and Middlebrook 7H9 medium gave comparable, high titres in fermenters. Flow cytometry proved to be a useful tool for enumeration of total bacterial counts and in the assessment of within-culture cell viability and cell death. Of the cryoprotectants evaluated, 5% (v/v) DMSO showed the most significant positive effect on survival and reduced the negative effects of low temperature storage on M. bovis BCG Danish viability. In conclusion, we have shown a reproducible, more standardised approach for the production, evaluation, and storage of high titre, viable, BCG vaccine. Full article

The DC microgrid system is composed by converters that operate like feeders and loads. Among these loads, we highlight the constant power loads (CPLs) that may cause instability in the microgrid, observed in the form of undesired oscillations due to its negative impedance behavior. Therefore, this work proposes to use performance indices and stability margins to evaluate state and output feedback control strategies for stabilization of DC microgrids. In particular, it is proposed to evaluate the stability margin of the proposed methodologies by means of the impedance relations in the microgrid based on the Middlebrook criterion. Our simulations and tests showed the relation between the performance and stability degradation and the microgrid impedances variation. Full article