179 research outputs found
A comparison of recall using factual study guides versus elaborative thinking study guides in grade four
Thesis (Ed.M.)--Boston University
N.B.: Missing pgs. 13
Effect of Varying Levels of Dietary Iron on Tissue Concentrations of Iron, Copper, and Zinc in Female Rats
An Abeis procera-derived tetracyclic triterpene containing a steroid-like nucleus core and a lactone side chain attenuates in vitro survival of both Fasciola hepatica and Schistosoma mansoni
Two economically and biomedically important platyhelminth species, Fasciola hepatica (liver fluke) and Schistosoma mansoni (blood fluke), are responsible for the neglected tropical diseases (NTDs) fasciolosis and schistosomiasis. Due to the absence of prophylactic vaccines, these NTDs are principally managed by the single class chemotherapies triclabendazole (F. hepatica) and praziquantel (S. mansoni). Unfortunately, liver fluke resistance to triclabendazole has been widely reported and blood fluke insensitivity/resistance to praziquantel has been observed in both laboratory settings as well as in endemic communities. Therefore, the identification of new anthelmintics is necessary for the sustainable control of these NTDs in both animal and human populations. Here, continuing our work with phytochemicals, we isolated ten triterpenoids from the mature bark of Abies species and assessed their anthelmintic activities against F. hepatica and S. mansoni larval and adult lifecycle stages. Full 1H and 13C NMR-mediated structural elucidation of the two most active triterpenoids revealed that a tetracyclic steroid-like nucleus core and a lactone side chain are associated with the observed anthelmintic effects. When compared to representative mammalian cell lines (MDBK and HepG2), the most potent triterpenoid (700015; anthelmintic EC50s range from 0.7 μM–15.6 μM) displayed anthelmintic selectivity (selectivity indices for F. hepatica: 13 for newly excysted juveniles, 46 for immature flukes, 2 for mature flukes; selectivity indices for S. mansoni: 14 for schistosomula, 9 for immature flukes, 4 for adult males and 3 for adult females) and induced severe disruption of surface membranes in both liver and blood flukes. S. mansoni egg production, a process responsible for pathology in schistosomiasis, was also severely inhibited by 700015. Together, our results describe the structural elucidation of a novel broad acting anthelmintic triterpenoid and support further investigations developing this compound into more potent analogues for the control of both fasciolosis and schistosomiasis. Keywords: Abies procera, Abies grandis, Triterpenoid, Anthelmintic drug discovery, Neglected tropical diseases, Fasciola hepatica, Schistosoma manson
Wolbachia and DNA barcoding insects: patterns, potential and problems
Wolbachia is a genus of bacterial endosymbionts that impacts the breeding systems of their hosts. Wolbachia can confuse the patterns of mitochondrial variation, including DNA barcodes, because it influences the pathways through which mitochondria are inherited. We examined the extent to which these endosymbionts are detected in routine DNA barcoding, assessed their impact upon the insect sequence divergence and identification accuracy, and considered the variation present in Wolbachia COI. Using both standard PCR assays (Wolbachia surface coding protein – wsp), and bacterial COI fragments we found evidence of Wolbachia in insect total genomic extracts created for DNA barcoding library construction. When >2 million insect COI trace files were examined on the Barcode of Life Datasystem (BOLD) Wolbachia COI was present in 0.16% of the cases. It is possible to generate Wolbachia COI using standard insect primers; however, that amplicon was never confused with the COI of the host. Wolbachia alleles recovered were predominantly Supergroup A and were broadly distributed geographically and phylogenetically. We conclude that the presence of the Wolbachia DNA in total genomic extracts made from insects is unlikely to compromise the accuracy of the DNA barcode library; in fact, the ability to query this DNA library (the database and the extracts) for endosymbionts is one of the ancillary benefits of such a large scale endeavor – for which we provide several examples. It is our conclusion that regular assays for Wolbachia presence and type can, and should, be adopted by large scale insect barcoding initiatives. While COI is one of the five multi-locus sequence typing (MLST) genes used for categorizing Wolbachia, there is limited overlap with the eukaryotic DNA barcode region
Flukicidal effects of abietane diterpenoid derived analogues against the food borne pathogen Fasciola hepatica.
Control of liver fluke infections remains a significant challenge in the livestock sector due to widespread distribution of drug resistant parasite populations. In particular, increasing prevalence and economic losses due to infection with Fasciola hepatica is a direct result of drug resistance to the gold standard flukicide, triclabendazole. Sustainable control of this significant zoonotic pathogen, therefore, urgently requires the identification of new anthelmintics. Plants represent a source of molecules with potential flukicidal effects and, amongst their secondary metabolites, the diterpenoid abietic acids can be isolated in large quantities. In this study, nineteen (19) chemically modified abietic acid analogues (MC_X) were first evaluated for their anthelmintic activities against F. hepatica newly excysted juveniles (NEJs, from the laboratory-derived Italian strain); from this, 6 analogues were secondly evaluated for their anthelmintic activities against adult wild strain flukes. One analogue, MC010, was progressed further against 8-week immature- and 12-week mature Italian strain flukes. Here, MC010 demonstrated moderate activity against both of these intra-mammalian fluke stages (with an adult fluke EC50 = 12.97 µM at 72 h post culture). Overt mammalian cell toxicity of MC010 was inferred from the Madin-Darby bovine kidney (MDBK) cell line (CC50 = 17.52 µM at 24 h post culture) and demonstrated that medicinal chemistry improvements are necessary before abietic acid analogues could be considered as potential anthelmintics against liver fluke pathogen
Forms of Understanding of XAI-Explanations
Explainability has become an important topic in computer science and
artificial intelligence, leading to a subfield called Explainable Artificial
Intelligence (XAI). The goal of providing or seeking explanations is to achieve
(better) 'understanding' on the part of the explainee. However, what it means
to 'understand' is still not clearly defined, and the concept itself is rarely
the subject of scientific investigation. This conceptual article aims to
present a model of forms of understanding in the context of XAI and beyond.
From an interdisciplinary perspective bringing together computer science,
linguistics, sociology, and psychology, a definition of understanding and its
forms, assessment, and dynamics during the process of giving everyday
explanations are explored. Two types of understanding are considered as
possible outcomes of explanations, namely enabledness, 'knowing how' to do or
decide something, and comprehension, 'knowing that' -- both in different
degrees (from shallow to deep). Explanations regularly start with shallow
understanding in a specific domain and can lead to deep comprehension and
enabledness of the explanandum, which we see as a prerequisite for human users
to gain agency. In this process, the increase of comprehension and enabledness
are highly interdependent. Against the background of this systematization,
special challenges of understanding in XAI are discussed
Randomized Controlled Trial to Evaluate an Internet‐Based Self‐Management Program in Systemic Sclerosis
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148240/1/acr23595.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148240/2/acr23595_am.pd
The prevalence of depression in general hospital inpatients: a systematic review and meta-analysis of interview-based studies.
BACKGROUND: Comorbid depression in the medically ill is clinically important. Admission to a general hospital offers an opportunity to identify and initiate treatment for depression. However, we first need to know how common depression is in general hospital inpatients. We aimed to address this question by systematically reviewing the relevant literature. METHODS: We reviewed published prevalence studies in any language which had used diagnostic interviews of general hospital inpatients and met basic methodological quality criteria. We focussed on interview-based studies in order to estimate the proportion of patients with a diagnosis of depressive illness. RESULTS: Of 158 relevant articles, 65 (41%) describing 60 separate studies met our inclusion criteria. The 31 studies that focussed on general medical and surgical inpatients reported prevalence estimates ranging from 5% to 34%. There was substantial, highly statistically significant, heterogeneity between studies which was not materially explained by the covariates we were able to consider. The average of the reported prevalences was 12% (95% CI 10-15), with a 95% prediction interval of 4-32%. The remaining 29 studies, of a variety of specific clinical populations, are described. CONCLUSIONS: The available evidence suggests a likely prevalence high enough to make it worthwhile screening hospital inpatients for depression and initiating treatment where appropriate. Further, higher quality, research is needed to clarify the prevalence of depression in specific settings and to further explore the reasons for the observed heterogeneity in estimates
Stepwise pathogenic evolution of Mycobacterium abscessus.
Although almost all mycobacterial species are saprophytic environmental organisms, a few, such as Mycobacterium tuberculosis, have evolved to cause transmissible human infection. By analyzing the recent emergence and spread of the environmental organism M. abscessus through the global cystic fibrosis population, we have defined key, generalizable steps involved in the pathogenic evolution of mycobacteria. We show that epigenetic modifiers, acquired through horizontal gene transfer, cause saltational increases in the pathogenic potential of specific environmental clones. Allopatric parallel evolution during chronic lung infection then promotes rapid increases in virulence through mutations in a discrete gene network; these mutations enhance growth within macrophages but impair fomite survival. As a consequence, we observe constrained pathogenic evolution while person-to-person transmission remains indirect, but postulate accelerated pathogenic adaptation once direct transmission is possible, as observed for M. tuberculosis Our findings indicate how key interventions, such as early treatment and cross-infection control, might restrict the spread of existing mycobacterial pathogens and prevent new, emergent ones
Regulators of G protein Signaling (RGS) proteins (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database
Regulators of G protein signalling (RGS) proteins display a common RGS domain that interacts with the GTP-bound Gα subunits of heterotrimeric G proteins, enhancing GTP hydrolysis by stabilising the transition state [29, 419, 418], leading to a termination of GPCR signalling. Interactions through protein:protein interactions of many RGS proteins have been identified for targets other than heteromeric G proteins. Sequence analysis of the 20 RGS proteins suggests four families of RGS: RZ, R4, R7 and R12 families. Many of these proteins have been identified to have effects other than through targetting G proteins. Included here is RGS4 for which a number of pharmacological inhibitors have been described
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