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Teaching methodologies used to promote critical thinking should be investigated to enhance the delivery of safe and effective care and to improve student success on the NCLEX-RN Exam. The purpose of this study was to examine the effects of a problem-based learning methodology on the critical thinking skills of associate degree nursing students in a 12-week NCLEX-Review Course. An experimental pre-post treatment comparative design was utilized to determine the effects of the two teaching methods on the critical thinking skills of fourth semester students enrolled in a NCLEX-Review Course. [ABSTRACT FROM AUTHOR]

One of the distinctive cutaneous manifestations of Bannayan-Riley-Ruvalcaba syndrome (BRRS), a PTEN hamartoma tumor syndrome, is penile pigmented macules. We present a 13-year-old boy with gingival hyperpigmentation along with facial and ear angiofibromas in the context of a BRRS-concordant phenotype and PTEN hamartoma tumor syndrome genotype. To our knowledge, these two findings have not been previously reported with BRRS and may expand the known phenotype of this disorder., (© 2021 Wiley Periodicals LLC.)

Background and Aims: Faecal diversion is associated with improvements in Crohn's disease but not ulcerative colitis, indicating that differing mechanisms mediate the diseases. This study aimed to investigate levels of systemic mediators of inflammation, including fibrocytes and cytokines, [1] in patients with Crohn's disease and ulcerative colitis preoperatively compared with healthy controls and [2] in patients with Crohn's disease and ulcerative colitis prior to and following faecal diversion., Methods: Blood samples were obtained from healthy individuals and patients with Crohn's disease or ulcerative colitis. Levels of circulating fibrocytes were quantified using flow cytometric analysis and their potential relationship to risk factors of inflammatory bowel disease were determined. Levels of circulating cytokines involved in inflammation and fibrocyte recruitment and differentiation were investigated., Results: Circulating fibrocytes were elevated in Crohn's disease and ulcerative colitis patients when compared with healthy controls. Smoking, or a history of smoking, was associated with increases in circulating fibrocytes in Crohn's disease, but not ulcerative colitis. Cytokines involved in fibrocyte recruitment were increased in Crohn's disease patients, whereas patients with ulcerative colitis displayed increased levels of pro-inflammatory cytokines. Faecal diversion in Crohn's disease patients resulted in decreased circulating fibrocytes, pro-inflammatory cytokines, and TGF-β1, and increased IL-10, whereas the inverse was observed in ulcerative colitis patients., Conclusions: The clinical effect of faecal diversion in Crohn's disease and ulcerative colitis may be explained by differing circulating fibrocyte and cytokine responses. Such differences aid in understanding the disease mechanisms and suggest a new therapeutic strategy for inflammatory bowel disease., (© European Crohn’s and Colitis Organisation (ECCO) 2019.)

Stereotype threat-a situational context in which individuals are concerned about confirming a negative stereotype-is often shown to impact test performance, with one hypothesized mechanism being that cognitive resources are temporarily co-opted by intrusive thoughts and worries, leading individuals to underperform despite high content knowledge and ability (see Schmader & Beilock, ). We test here whether stereotype threat may also impact initial student learning and knowledge formation when experienced prior to instruction. Predominantly African American fifth-grade students provided either their race or the date before a videotaped, conceptually demanding mathematics lesson. Students who gave their race retained less learning over time, enjoyed the lesson less, reported a diminished desire to learn more, and were less likely to choose to engage in an optional math activity. The detrimental impact was greatest among students with high baseline cognitive resources. While stereotype threat has been well documented to harm test performance, the finding that effects extend to initial learning suggests that stereotype threat's contribution to achievement gaps may be greatly underestimated., (Copyright © 2017 Cognitive Science Society, Inc.)

Individual differences in Executive Function (EF) are well established to be related to overall mathematics achievement, yet the mechanisms by which this occurs are not well understood. Comparing representations (problems, solutions, concepts) is central to mathematical thinking, and relational reasoning is known to rely upon EF resources. The current manuscript explored whether individual differences in EF predicted learning from a conceptually demanding mathematics lesson that required relational reasoning. Analyses revealed that variations in EF predicted learning when measured at a delay, controlling for pretest scores. Thus, EF capacity may impact students' overall mathematics achievement by constraining their resources available to learn from cognitively demanding reasoning opportunities in everyday lessons. To assess the ecological validity of this interpretation, we report follow-up interviews with mathematics teachers who raised similar concerns that cognitively demanding activities such as comparing multiple representations in mathematics may differentially benefit their high versus struggling learners. Broader implications for ensuring that all students have access to, and benefit from, conceptually rich mathematics lessons are discussed. We also highlight the utility of integrating methods in Science of Learning (SL) research.

The predatory bacterium, Vampirovibrio chlorellavorus, can destroy a Chlorella culture in just a few days, rendering an otherwise robust algal crop into a discolored suspension of empty cell walls. Chlorella is used as a benchmark for open pond cultivation due to its fast growth. In nature, V. chlorellavorus plays an ecological role by controlling this widespread terrestrial and freshwater microalga, but it can have a devastating effect when it attacks large commercial ponds. We discovered that V. chlorellavorus was associated with the collapse of four pilot commercial-scale (130,000 L volume) open-pond reactors. Routine microscopy revealed the distinctive pattern of V. chlorellavorus attachment to the algal cells, followed by algal cell clumping, culture discoloration and ultimately, growth decline. The "crash" of the algal culture coincided with increasing proportions of 16s rRNA sequencing reads assigned to V. chlorellavorus. We designed a qPCR assay to predict an impending culture crash and developed a novel treatment to control the bacterium. We found that (1) Chlorella growth was not affected by a 15 min exposure to pH 3.5 in the presence of 0.5 g/L acetate, when titrated with hydrochloric acid and (2) this treatment had a bactericidal effect on the culture (2-log decrease in aerobic counts). Therefore, when qPCR results indicated a rise in V. chlorellavorus amplicons, we found that the pH-shock treatment prevented the culture crash and doubled the productive longevity of the culture. Furthermore, the treatment could be repeatedly applied to the same culture, at the beginning of at least two sequential batch cycles. In this case, the treatment was applied preventively, further increasing the longevity of the open pond culture. In summary, the treatment reversed the infection of V. chlorellavorus as confirmed by observations of bacterial attachment to Chlorella cells and by detection of V. chlorellavorus by 16s rRNA sequencing and qPCR assay. The pH-shock treatment is highly selective against prokaryotes, and it is a cost-effective treatment that can be used throughout the scale up and production process. To our knowledge, the treatment described here is the first effective control of V. chlorellavorus and will be an important tool for the microalgal industry and biofuel research.

Aims: The aim of this study was to determine if endophytes from wild and ancient Zea plants (corn family) have anti-fungal activities, specifically against the most important fungal pathogen (Sclerotinia homoeocarpa) of creeping bentgrass, a relative of Zea, used here as a model grass., Methods and Results: A library of 190 bacterial endophytes from wild, ancient and modern Zea plants were tested for their ability to suppress S. homoeocarpa in vitro, followed by in planta testing of candidates using greenhouse trials. Three endophytes could suppress S. homoeocarpa, originating from wild maize and an ancient Mexican landrace, consistent with our hypothesis. 16S phylogenetic analysis and BOX-PCR DNA fingerprinting suggest that the anti-fungal endophytes are distinct strains of Burkholderia gladioli. One strain (3A12) was confirmed to colonize creeping bentgrass using green fluorescent protein (GFP) tagging. Evans blue vitality staining demonstrated that the bacterial endophytes exhibited fungicidal activities against the pathogen. The endophytes inhibited a wide spectrum of plant-associated fungi including diverse crop pathogens., Conclusions: The results support the hypothesis that wild and ancient Zea genotypes host bacterial endophytes that can control fungal pathogen(s)., Significance and Impact of the Study: These results suggest that wild and ancient crops may be an unexplored reservoir of anti-fungal bacterial endophytes., (© 2016 The Society for Applied Microbiology.)

Background: Endophytes are microbes that inhabit internal plant tissues without causing disease. Plant microbial communities consist of large numbers of endophyte species. Understanding the functions of these endophytes is a major challenge. An important function of some endophytes is to suppress fungal pathogens. Typically, plant associated microbes are screened for anti-fungal activities in vitro using the high-throughput dual culture screen, but it is not clear whether this method correlates with the activities of these microbes in planta. Furthermore, it is not clear whether in vitro screening captures all of the microbes that show this activity inside plants. The objective of this study was to evaluate the relevance of the in vitro dual culture method for screening endophytes with anti-fungal activity., Results: In parallel, 190 bacterial endophytes from the corn grass family (Zea) were screened for suppression of two fungal pathogens (Sclerotinia homoeocarpa and Rhizoctonia solani) using the in vitro dual culture method, and in planta using the model plant, creeping bentgrass. All endophytes that showed anti-fungal activity in planta against Sclerotinia homoeocarpa and Rhizoctonia solani (3 or 4 strains, respectively, out of 190), were captured in vitro. The in vitro and in planta screening results strongly correlated (r = 0.81 and r = 0.94 for the two pathogens, respectively)., Conclusions: Evidence was gained here that the in vitro dual culture method is a relevant method for high throughput screening of plant endophyte communities for anti-fungal activity. In our study, the method captured all of the microbes that suppressed the corresponding pathogens in planta.

This article describes the implementation and evaluation of an eight-hour, comprehensive, face-to-face orientation program designed to improve student retention in a newly developed online RN to BSN program. A total of 179 newly enrolled RN to BSN students participated in the orientation program and evaluated the process. Student attrition decreased from 20 percent to less than 1 percent after the orientation program was extended and improved to include a technology assessment and an online practice course. A quality online program requires a well-designed orientation that includes technological assessments and hands-on, active participation by the learner. The newly improved and designed course has become effective in student retention and transition into the online learning environment.

Anabaena variabilis ATCC 29413 is a filamentous heterocystous cyanobacterium that fixes nitrogen under a variety of environmental conditions. Under aerobic growth conditions, nitrogen fixation depends upon differentiation of heterocysts and expression of either a Mo-dependent nitrogenase or a V-dependent nitrogenase in those specialized cells. Under anaerobic conditions, a second Mo-dependent nitrogenase gene cluster, nifII, was expressed in vegetative cells long before heterocysts formed. A strain carrying a mutant gene in the nifII cluster did not fix nitrogen under anaerobic conditions until after heterocysts differentiated. The nifII cluster was similar in organization to the nifI cluster that is expressed in heterocysts and that includes nifBSUHDKENXW as well as three open reading frames that are conserved in both cyanobacterial nif clusters.

In many filamentous cyanobacteria nitrogen fixation occurs in differentiated cells called heterocysts. Filamentous strains that do not form heterocysts may fix nitrogen in vegetative cells, primarily under anaerobic conditions. We describe here two functional Mo-dependent nitrogenases in a single organism, the cyanobacterium Anabaena variabilis. Using a lacZ reporter with a fluorescent beta-galactoside substrate for in situ localization of gene expression, we have shown that the two clusters of nif genes are expressed independently. One nitrogenase functions only in heterocysts under either aerobic or anaerobic growth conditions, whereas the second nitrogenase functions only under anaerobic conditions in vegetative cells and heterocysts. Differences between the two nif clusters suggest that the nitrogenase that is expressed in heterocysts is developmentally regulated while the other is regulated by environmental factors.

Anabaena variabilis ATCC 29413 is a heterotrophic, nitrogen-fixing cyanobacterium containing both a Mo-dependent nitrogenase encoded by the nif genes and V-dependent nitrogenase encoded by the vnf genes. The nifB, nifS, and nifU genes of A. variabilis were cloned, mapped, and partially sequenced. The fdxN gene was between nifB and nifS. Growth and acetylene reduction assays using wild-type and mutant strains indicated that the nifB product (NifB) was required for nitrogen fixation not only by the enzyme encoded by the nif genes but also by the enzyme encoded by the vnf genes. Neither NifS nor NifU was essential for nitrogen fixation in A. variabilis.