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Toxoplasma gondii is the causative agent of toxoplasmosis, and an important problem of public health. The current treatment for toxoplasmosis is the combination of pyrimethamine and sulphadiazine, which do not act in the chronic phase of toxoplasmosis and have several side-effects. This study evaluated the anti-T. gondii activity and potential mechanism of Moringa oleifera seeds’ aqueous extract in vitro. The concentration of M. oleifera extract in HeLa cells was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell viability assays. The presence of T. gondii was assessed by quantitative polymerase chain reaction and toluidine blue staining. Pyrimethamine and sulphadiazine were used as drug controls. Modifications in T. gondii morphology and ultrastructure were observed by electron microscopy. In vitro, the M. oleifera extract had no toxic effect on HeLa cells at concentrations below 50 μg mL−1. Moringa oleifera extract inhibits T. gondii invasion and intracellular proliferation with similar results for sulphadiazine + pyrimethamine, and also shows cellular nitric oxide production at a concentration of 30 μg mL−1. Electron microscopy analyses indicated structural and ultrastructural modifications in tachyzoites after treatment. We also observed an increase in reactive oxygen species production and a loss of mitochondrial membrane integrity. Nile Red staining assays demonstrated a lipid accumulation. Annexin V–fluorescein isothiocyanate and propidium iodide staining demonstrated that the main action of M. oleifera extract in T. gondii tachyzoites was compatible with late apoptosis. In conclusion, M. oleifera extract has anti-T. gondii activity in vitro and might be a promising substance for the development of a new anti-T. gondii drug.
This study investigates the use of augmented reality technology (AR) in the field of maritime navigation and how researchers and designers have addressed AR data visualisation. The paper presents a systematic review analysing the publication type, the AR device, which information elements are visualised and how, the validation method and technological readiness. Eleven AR maritime solutions identified from scientific papers are studied and discussed in relation to previous navigation tools. It is found that primitive information such as course, compass degrees, boat speed and geographic coordinates continue to be fundamental information to be represented even with AR maritime solutions.
Qualitative scholars exhibit a wide range of views on and approaches to causality. While some approaches reject causality from the outset, a large strand of qualitative research in political science and international relations does, however, pursue causal explanation. Qualitative scholars nevertheless disagree about what causality means. Our paper reviews what causality means within different strands of qualitative research and how qualitative scholars engage in causal explanations. We focus particular attention on the fertile middle ground between qualitative research that seeks to mimic the statistical model and research that rejects causality entirely. In broad strokes, we understand views of causality as lying on a spectrum and partly overlapping. Along the spectrum, we identify three main clusters: ‘positivist leaning,’ ‘postpositivist leaning,’ and ‘interpretivist leaning.’ Within each cluster, we identify the main traits and provide illustrative examples. We find merit in each of these three clusters of approaches and in the ongoing dialogue among qualitative scholars of different orientations. Understanding similarities and differences in the way various scholars address causality might encourage some to take steps along the spectrum and expand their repertoires to embrace elements of other approaches. By making these distinctions more explicit, we hope to be able to enhance our understanding of different views of causality and the extent to which they overlap and provide the potential for collaboration.
The systems ecology paradigm (SEP) emerged in the late 1960s at a time when societies throughout the world were beginning to recognize that our environment and natural resources were being threatened by their activities. Management practices in rangelands, forests, agricultural lands, wetlands, and waterways were inadequate to meet the challenges of deteriorating environments, many of which were caused by the practices themselves. Scientists recognized an immediate need was developing a knowledge base about how ecosystems function. That effort took nearly two decades (1980s) and concluded with the acceptance that humans were components of ecosystems, not just controllers and manipulators of lands and waters. While ecosystem science was being developed, management options based on ecosystem science were shifting dramatically toward practices supporting sustainability, resilience, ecosystem services, biodiversity, and local to global interconnections of ecosystems. Emerging from the new knowledge about how ecosystems function and the application of the systems ecology approach was the collaboration of scientists, managers, decision-makers, and stakeholders locally and globally. Today’s concepts of ecosystem management and related ideas, such as sustainable agriculture, ecosystem health and restoration, consequences of and adaptation to climate change, and many other important local to global challenges are a direct result of the SEP.
Fundamental knowledge about the processes that control the functioning of the biophysical workings of ecosystems has expanded exponentially since the late 1960s. Scientists, then, had only primitive knowledge about C, N, P, S, and H2O cycles; plant, animal, and soil microbial interactions and dynamics; and land, atmosphere, and water interactions. With the advent of systems ecology paradigm (SEP) and the explosion of technologies supporting field and laboratory research, scientists throughout the world were able to assemble the knowledge base known today as ecosystem science. This chapter describes, through the eyes of scientists associated with the Natural Resource Ecology Laboratory (NREL) at Colorado State University (CSU), the evolution of the SEP in discovering how biophysical systems at small scales (ecological sites, landscapes) function as systems. The NREL and CSU are epicenters of the development of ecosystem science. Later, that knowledge, including humans as components of ecosystems, has been applied to small regions, regions, and the globe. Many research results that have formed the foundation for ecosystem science and management of natural resources, terrestrial environments, and its waters are described in this chapter. Throughout are direct and implicit references to the vital collaborations with the global network of ecosystem scientists.
Ecosystem science and the systems ecology paradigm co-evolved starting in the late 1960s within the milieu of substantial research funding from the US National Science Foundation-supported US International Biological Program (IBP). Nationally, educational programs focusing on ecosystem structure and functioning, and mathematical modeling, were slow to develop except at Colorado State University (CSU). There, leaders in the Natural Resource Ecology Laboratory (NREL) and the Department of Range Science (DRS) established internationally recognized interdisciplinary programs and outreach in basic and applied ecosystem science and systems ecology. Operating from the sound research base within a major Land Grant University (CSU), the NREL, with IBP funding, supported many graduate students housed in the academic DRS. As the systems ecology approach expanded, other ecosystem-focused research programs developed, and graduate students entered other academic departments. Outgrowths from the early diffused educational training were innovative cross-departmental and cross-college programs addressing the systems ecology paradigm. Recently, a new Department of Ecosystem Science and Sustainability was established housing both graduate and undergraduate programs. As formal academic training developed on-campus, environmental literacy efforts were developed, including: training programs for K-12 students and teachers; online distance education programs; Citizen Science training; and numerous institutes, short courses, and workshops.
Survivors of single ventricle heart disease must cope with the physical, neurodevelopmental, and psychosocial sequelae of their cardiac disease, which may also affect academic achievement and social relationships. The purpose of this study was to qualitatively examine the experiences of school and social relationships in adolescents with single ventricle heart disease.
A descriptive phenomenological methodology was employed, utilising semi-structured interviews. Demographic and clinical characteristics were obtained via chart review.
Fourteen adolescents (aged 14 to 19 years) with single ventricle heart disease participated. Interviews ranged from 25 to 80 minutes in duration. Four themes emerged from the interviews, including “Don’t assume”: Pervasive ableism; “The elephant in the room”: Uncertain future; “Everyone finds something to pick on”: Bullying at school; “They know what I have been through”: Social support. The overall essence generated from the data was “optimism despite profound uncertainty.”
Adolescents with single ventricle heart disease identified physical limitations and school challenges in the face of an uncertain health-related future. Despite physical and psychosocial limitations, most remained optimistic for the future and found activities that were congruent with their abilities. These experiences reflect “optimism despite profound uncertainty.”
Rivulidae comprises a family of fish largely distributed in Brazil that includes 201 species, of which 125 are considered endangered. This fact emphasizes the need for development of conservation strategies including studies on genetics and reproduction. In this paper, we describe aspects of biology and reproduction of the rivuliid species Hypsolebias sertanejo. We outline the reproductive behaviour of this species under laboratory conditions, analyze ploidy status by flow cytometry, describe reproductive behaviour and performance and test dry and wet incubation of eggs. Although H. sertanejo showed well known patterns of reproductive behaviour, we verified many peculiarities inherent to its reproductive biology. As expected, most individuals were diploid (87.71%), however 14.29% were considered mosaics. Although no sterility was observed within mosaics, infertility of these fish was not fully evaluated. Hatching rate of the eggs collected was very low following both dry and wet incubation (5.04 and 3.79%, respectively). These results provide interesting information regarding the reproductive success of this species, and suggest that chromosomal abnormalities described may reduce the survival of H. sertanejo under natural conditions, limiting the perpetuation of this species, and emphasizing the need for more preservation efforts, including artificial propagation and gene banking.
Background: A surgical instrument can have areas that pose different challenges to cleaning, hindering the removal of dirt. This can directly impact the effectiveness of its processing while potentially promoting cross contamination. Moreover, structural changes (ie, cracks or fissures) on the instrument surface, although rarely addressed, can act as reservoirs for microorganisms, contributing to organic matter retention, microbial growth, and biofilm formation. Our aim was to determine the effect of irregularities in the microstructure of surgical instruments on microbial adherence. Methods: We analyzed 18 fragments of 3 distinct areas of new crile forceps: the ratchet, shank, and jaw. Of these fragments, 15 were artificially contaminated by immersion in tryptic soy broth containing 10 6 CFU/mL of Escherichia coli (ATCC 25922), for 4, 6, 8, and 12 hours of incubation at 37C with agitation at 100 rpm. The other 3 fragments were used as controls. All fragments were subjected to scanning electron microscopy to evaluate the adhesion of the microorganism. Results: An irregular surface was found in 3 of 6 shank fragments (50%) (Fig. 1) and in all the jaw and ratchet fragments, grooves, and cracks. Initially, there was less adherence of E. coli to the smooth shank surface after contamination, but the concentration of the microorganism increased progressively over time in relation to that in the jaw or ratchet at the same time, and a higher concentration occurred in the cracks and grooves. Conclusions: Structural damage was observed in all fragments, especially in the ratchet and jaw areas, favoring microbial accumulation. Microorganisms housed in the cracks and grooves were better protected from removal by scrubbing with a brush (being unlikely to reach them), making these areas a microbial reservoir and source of contamination. Prolonged contact of the instrument with the contaminating microorganism allowed for greater adherence, even on the smooth areas. The results support the relevance of the early onset of cleaning, considering that even microscopic changes on the surface of the instrument may represent an additional challenge to its effective processing.
OBJECTIVES/GOALS: Identify the interactions between nasopharyngeal bacterial pathogens, commensals, and patient clinical characteristics in relation to the development of viral upper respiratory tract infections (URI) and acute otitis media (AOM) in infants. METHODS/STUDY POPULATION: The subjects were part of a prospective, longitudinal study (2008–2014) of infants to evaluate the prevalence and risks for the development of URI and AOM. Healthy infants (n = 362) were enrolled from near birth and followed to the first episode of AOM up to 12 months of age. Nasopharyngeal specimens and clinical traits were collected at monthly intervals between 1-6 months, month 9, and during viral URI episodes. Subjects were closely followed for AOM development. 16S rRNA sequencing was performed on the nasopharyngeal swabs to identify their bacterial composition. Multidimensional (2, 3, and 4 dimensional) co-presence, co-exclusion, and one-way relation patterns were identified between the microbiome compositions, health status, and other collected clinical traits. RESULTS/ANTICIPATED RESULTS: We analyzed 971 specimens collected monthly and during URI and AOM episodes from 139 infants. Of the 139 enrolled subjects, 96% had 2 or more healthy samples, 77% contracted URI/AOM during the study period, and 60% had at least 1 healthy sample before URI/AOM onset. Otopathogens (Moraxella, Haemophilus, and Streptococcus), Staphylococcus, and Pseudomonas were the most common pathogenic genera. Corynebacterium, Dolosigranulum, and Acinetobacter were 3 most abundant commensal bacterial genera. Samples from infants with AOM in the first year had a significantly higher relative abundance of Haemophilus, Enterobacter, and Yersinia, and lower relative abundance of Corynebacterium, and Pseudomonas compared to samples from infants who did not develop AOM. DISCUSSION/SIGNIFICANCE OF IMPACT: Identification of complex multidimensional interaction patterns within microbial communities and environmental factors is vital to understanding disease onset risk and prevention. Prophylactic microbiome and environmental factor modulation between enterotypes could be used to reduce URI/AOM onset in infants.
Human immunodeficiency virus-1 (HIV-1) is characterised by a vast genetic diversity classified into distinct phylogenetic strains and recombinant forms. We describe the HIV-1 molecular epidemiology and evolution of 129 consecutive HIV-1 positive migrants living in Milan (northern Italy). Polymerase gene sequences of 116 HIV-1 subtype-B positive patients were aligned with HIV-1 reference sequences (https://www.ncbi.nlm.nih.gov/) by using MAFFT alignment and edited by using Bioedit software. A maximum likelihood (ML) phylogenetic tree was performed by MEGA7 and was visualised by using FigTree v1.4.3. Of 129 migrants, 35 were born in Europe (28 in Eastern Europe), 70 in the Americas (67 in South America), 15 in Africa and nine in Asia; 76.4% were men who have sex with men (MSM). The serotype HIV-1-B prevailed (89.9%), followed by -C, -F1, -D and -A. Compared with 116 HIV-B patients, the 13 with HIV-non-B showed lower Nadir of CD4+ cell/mmc (P = 0.043), more frequently had sub Saharan origin (38.5 vs. 1.72%, P = 0.0001) and less frequently were MSM (40 vs. 74.5%, P = 0.02). The ML phylogenetic tree of the 116 HIV-1 subtype-B positive patients showed 13 statistically supported nodes (bootstrap > 70%). Most of the sequences included in these nodes have been isolated from male patients from the Americas and the most common risk factor was MSM. The low number of HIV-1 non-B subtype patients did not allow to perform this analysis. These results suggest a shift of HIV-1 prevention projects' focus and a continuous monitoring of HIV-1 molecular epidemiology among entry populations. Prevention efforts based on HIV molecular epidemiology may improve public health surveillance setting.
This study evaluated the effects of rosuvastatin in vivo on toxoplasmosis chronic infection. Thirty-five Swiss mice were orally infected (ME-49 strain). After 50 days, the mice were separated into five groups: GI – non-infected, GII – infected, GIII – infected and treated with pyrimethamine and sulfadiazine (12.5 + 50 mg kg−1 body weight day−1), GIV and GV – infected and treated with rosuvastatin 10 and 40 mg kg−1 body weight day−1, respectively. After 21 days, we collected blood, liver, lungs, femoral biceps and brain were removed for Toxoplasma gondii DNA quantification by qPCR and histopathological analysis. GIV and GV did not present premature death or clinical changes, and the hepatic enzyme levels were lower compared to GI. Toxoplasma gondii DNA was detected mainly in brain and muscle, but the parasite load was significantly lower in GV compared to GII brains (P < 0.05). Histopathological changes were observed in brains, with T. gondii cysts as well as an inflammatory condition, including necrosis areas in GII and GIII. These data confirm active infection with tissue injury. This inflammatory condition was attenuated in the groups treated with rosuvastatin, especially R40 (GV). Our findings demonstrated the in vivo action of rosuvastatin in reducing cerebral parasitic load and indicate that this drug may interfere in chronic toxoplasmosis.
Arthur Symons’s ‘The Decadent Movement in Literature’ (1893) introduced decadence to English readers by insisting that decadence should be seen as ‘[t]he latest movement in European literature’, rejecting the proposition that decadence might have any exclusively national affiliation. Authors associated with decadence are ‘transnational’ in the sense that they responded to the challenges of working in a space that simultaneously ranged across nations and reached beyond the nation as an ideologically constructed marker of identity. This transnational re-orientation affected the decadents’ taste, modes of production, and individual identities. In short, decadents were aware of inhabiting a transnational field, and they knew that this very awareness formed a key constitutive element of their notoriously slippery shared identity. Indeed, the act of questioning national identity and national feeling was an important part of the decadents’ ethos of transgression. The transnational impulse was thus intimately related to decadent modes of dissent from the bourgeois habitus and sexual morality, as well as from traditionalist requirements of conventional literature.
The Abrolhos bank, in southern Bahia State (BA), is the largest coral reef system in the southwestern Atlantic. It is highly influenced by the Brazil Current (BC), since it is located in the continental shelf. By contrast, Todos os Santos Bay (TSB), in Salvador, capital of Bahia State (BA) has an important coral biodiversity, located in a bay inlet with restricted water circulation. Coral cores were collected in those sites and were analyzed for density band counting and by Th/U dating to estimate growth rates and age. In this work, we present 14C ages of some of these bands in order to evaluate the marine reservoir effect (MRE) to which the colonies were subjected during growth. It is the first study making use of coral skeleton samples for MRE determination for the Brazilian coast. ΔR was calculated to be –151±23 14C yr, while that for the TSB was –107±51 14C yr.
The use of concrete-recycled aggregates to produce high-performance concrete is limited by insufficient correlation between resulting microstructure and its influence on mechanical performance reproducibility. This work addresses this issue in a sequential approach: concrete microstructure was systematically analyzed and characterized by scanning electron microscopy and results were correlated with concrete compressive strength and water absorption ability. The influence of replacing natural aggregates (NA) with recycled concrete aggregates (RCA), with different source concrete strength levels, of silica fume (SF) addition and of mixing procedure was tested. The results show that the developed microstructure depends on the concrete composition and is conditioned by the distinct nature of NA, recycled aggregates from high-strength source concrete, and recycled aggregates from low-strength source concrete. SF was only effective at concrete densification when a two-stage mixing approach was used. The highest achieved strength in concrete with 100% incorporation of RCA was 97.3 MPa, comparable to that of conventional high-strength concrete with NA. This shows that incorporation of significant amounts of RCA replacing NA in concrete is not only a realistic approach to current environmental goals, but also a viable route for the production of high-performance concrete.
There are few reports of cryopreservation and injuries in Macrobrachium amazonicum embryos. Thus, the aim of this study was to analyze the effects of cryoprotectants agents and cooling on stage VIII of this species. Fertilized eggs from ovigerous females were removed from the incubation chamber, then placed in 10 ml Falcon tubes with a cryoprotectant solution and saline-free calcium solution. Thus, the embryos underwent a cooling curve of 1°C per min until reaching 5°C, and then were stored for 2 h. The tubes containing the embryos were washed to remove the cryoprotectant, acclimated for 5 min and then transferred to 50 ml incubators. At the end of the 24-h period, living embryos from each tube were counted and tabulated. A pool of embryos was fixed with 4% formaldehyde and then subjected to histology using 3-mm thick sections and stained with haematoxylin/eosin. Another pool was used for biometric analysis in which length, width and volume were analyzed. The cryoprotectants agents used were: dimethylsulfoxide (DMSO), methyl alcohol, ethylene glycol at 1, 5 and 10% and sucrose (0.5 M). Variance analysis was performed followed by Tukey's honest significant difference (HSD) test at 5% significance level. DMSO cryoprotectant affected embryo survival the least with rates of 71.8, 36.2 and 0% for concentrations of 1, 5 and 10%, respectively. Ethylene glycol caused 100% mortality at all the concentrations used. It was not possible to observe the interference of cooling and cryoprotectants on embryonic structures in this study.
The very irregular state of motion observed by Robert Brown for small pollen grains suspended in water initiated one of the the most fascinating fields of science. The importance of such discovery – the so-called diffusion process – is immeasurable; it has been found in many contexts and is widespread in nature. A characteristic feature of this random motion is the linear growth with time exhibited by the mean square displacement, which is typical of a Markovian process. In contrast with this situation, a large class of systems and processes present a diffusion behaviour characterised by a nonlinear time dependence of the same quantity, thus constituting what is called anomalous diffusion behaviour.
The last decades have witnessed an increased interest in the anomalous diffusion processes that seem to be indeed present in a variety of experimental scenarios in physics, chemistry, biology, and several other branches of engineering; it is a rapidly growing field of research, attracting the attention of the scientific community. This happens from the theoretical side – due to the new mathematical problems evoked – but also from the point of view of experimental or practical applications. It is noteworthy that the number of studies reporting experimental problems dealing with anomalous diffusion has strongly increased – this attests to the ubiquity of a phenomenon initially considered a rare event.
The power of the mathematical tools based on fractional calculus, on the other hand, has also attracted the attention of the community working with pure and applied mathematics. The association of these techniques with the diffusional problem represents in practice a new field of research. It was shown in several ways that fractional calculus, if it is not unique, is nevertheless a suitable or even the natural mathematical framework to use to face the high complexity represented by anomalous diffusion phenomena. One powerful way of using these mathematical tools to analyse diffusion processes leads naturally to the necessity to search for solutions of fractional linear and nonlinear diffusion equations.
This chapter presents the pathway towards the construction of Poisson–Nernst– Planck anomalous (PNPA) models proposed to connect the anomalous diffusion phenomenon with the impedance spectroscopy. The first part is dedicated to analysing the conceptual links between a PNPA model and equivalent electrical circuits containing constant-phase elements (CPEs) in the low frequency domain. It is demonstrated, on analytical grounds, that the effect of a CPE in an equivalent electrical circuit may be represented by an appropriate term added to the boundary conditions of PNP or PNPA models. The second part recalls the fundamental equations of the PNPA models, including also reaction terms and Ohmic boundary conditions to account for more complex bulk and interfacial behaviour. It is shown that the formulation based on the fractional diffusion equations establishes on general theoretical grounds a connection between the PNPA models with an entire framework of continuum models and equivalent circuits with CPEs to analyse impedance data.
PNPA Models and Equivalent Circuits
As we have seen in Chapter 9, the continuum models frequently used to analyse the data are essentially based on diffusion-like equations for the ions, satisfying the Poisson's equation requirement for the electric potential (Poisson–Nernst–Planck or PNP model), or on equivalent electrical circuits . There are various distributed circuit elements that can be incorporated into equivalent circuits . However, a careful analysis is necessary before reaching to general conclusions about the data, since the incorrect choice of the equivalent circuit can lead to deceptive conclusions about the process that occurs in the sample .
Even more powerful and useful general models, such as ordinary (PNP) or anomalous diffusion (PNPA) ones, are not free from ambiguities . On one hand, the PNPA models aim at incorporating behaviours that may not be well described in terms of usual diffusive PNP models. On the other hand, an important extension used in the framework of equivalent circuits is the CPE, whose presence can be connected with the necessity of describing unusual effects in many solid electrode–electrolyte interfaces. For instance, it has been pointed out that simple elements cannot describe frequency dispersion often found in the solid electrode– electrolyte interfacial region . This behaviour can be related to surface disorder and roughness [346–349], electrode porosity , and electrode geometry .