Shifting Responsibility for Learning From the Teacher to the Student

This paper discusses a personal approach to teaching ESL which encourages greater student responsibility in the learning process. The project is designed to assist teachers who are interested in developing a teaching style which increases student initiative with the goal of helping students become increasingly independent, self-directed learners. The project is organized into two main sections. The first is a discussion of the rationale and implications for teachers and students in this approach to teaching. Included also is a discussion regarding the necessity of meeting the affective needs of the learner. The second section presents a variety of different activities and techniques the author has used in the classroom to implement an approach of this kind

The Use of Visible Geostationary Operational Meteorological Satellite Imagery in Mapping the Water Balance over Puerto Rico for Water Resource Management

A solar insolation satellite remote sensing product for Puerto Rico, the US Virgin Islands (USVI), Dominican Republic, Haiti, Jamaica, and Cuba became available in 2009 through a collaboration between the University of Puerto Rico-Mayagüez Campus and the University of Alabama in Huntsville. Solar insolation data are available at 1 km resolution for Puerto Rico and the USVI and 2 km resolution for the other islands, as derived from 500 m resolution GOES-16 visible imagery. The insolation data demonstrate the powerful utility of satellite-derived fields for water resource applications, specifically the routine production of potential and reference evapotranspiration. This chapter describes the theoretical background and technical approach for estimating components of the daily water and energy balance in Puerto Rico. Useful information can be obtained from the model, which benefits disaster and emergency management, agriculture, human health, ecology, coastal water management, and renewable energy development at the island scale

Molecular Characterisation of Vancomycin-Resistant Enterococcus faecium Isolates Belonging to the Lineage ST117/CT24 Causing Hospital Outbreaks

Background: Vancomycin-resistant Enterococcus faecium (VREfm) is a successful nosocomial pathogen. The current molecular method recommended in the Netherlands for VREfm typing is based on core genome Multilocus sequence typing (cgMLST), however, the rapid emergence of specific VREfm lineages challenges distinguishing outbreak isolates solely based on their core genome. Here, we explored if a detailed molecular characterisation of mobile genetic elements (MGEs) and accessory genes could support and expand the current molecular typing of VREfm isolates sharing the same genetic background, enhancing the discriminatory power of the analysis. Materials/Methods: The genomes of 39 VREfm and three vancomycin-susceptible E. faecium (VSEfm) isolates belonging to ST117/CT24, as assessed by cgMLST, were retrospectively analysed. The isolates were collected from patients and environmental samples from 2011 to 2017, and their genomes were analysed using short-read sequencing. Pangenome analysis was performed on de novo assemblies, which were also screened for known predicted virulence factors, antimicrobial resistance genes, bacteriocins, and prophages. Two representative isolates were also sequenced using long-read sequencing, which allowed a detailed analysis of their plasmid content. Results: The cgMLST analysis showed that the isolates were closely related, with a minimal allelic difference of 10 between each cluster's closest related isolates. The vanB-carrying transposon Tn1549 was present in all VREfm isolates. However, in our data, we observed independent acquisitions of this transposon. The pangenome analysis revealed differences in the accessory genes related to prophages and bacteriocins content, whilst a similar profile was observed for known predicted virulence and resistance genes. Conclusion: In the case of closely related isolates sharing a similar genetic background, a detailed analysis of MGEs and the integration point of the vanB-carrying transposon allow to increase the discriminatory power compared to the use of cgMLST alone. Thus, enabling the identification of epidemiological links amongst hospitalised patients

Reconstruction of the superior vena cava: Benefits of postoperative surveillance and secondary endovascular interventions

AbstractPurpose: Superior vena cava (SVC) reconstructions are rarely performed; therefore the need for surveillance and the results of secondary interventions are unknown. Methods: During a 14-year period 19 patients (11 male, 8 female; mean age 41.9 years, range 8 to 69 years) underwent SVC reconstruction for symptomatic nonmalignant disease. Causes included mediastinal fibrosis (n = 12), indwelling foreign bodies (n = 4), idiopathic thrombosis (n = 2), and antithrombin III deficiency (n = 1). Spiral saphenous vein graft (n = 14), polytetrafluoroethylene (n = 4), or human allograft (n = 1) was implanted. Results: No early death or pulmonary embolism occurred. Four early graft stenoses or thromboses (spiral saphenous vein graft, n = 2, polytetrafluoroethylene, n = 2) required thrombectomy, with success in three. During a mean follow-up of 49.5 months (range, 4.7 to 137 months), 95 imaging studies were performed (average, five per patient; range, one to 10 studies). Venography detected mild or moderate graft stenosis in seven patients; two progressed to severe stenosis. Two additional grafts developed early into severe stenosis. Four of 19 grafts occluded during follow-up (two polytetrafluoroethylene, two spiral saphenous vein graft). Computed tomography failed to identify stenosis in two grafts, magnetic resonance imaging failed to confirm one stenosis and one graft occlusion, and duplex scanning was inconclusive on graft patency in 10 patients. Angioplasty was performed in all four patients with severe stenosis, with simultaneous placement of Wallstents in two. One of the Wallstents occluded at 9 months. Repeat percutaneous transluminal angioplasty was necessary in two patients, with placement of Palmaz stents in one. Only one graft occlusion and one severe graft stenosis occurred beyond 1 year. The primary, primary-assisted, and secondary patency rates were 61%, 78%, and 83% at 1 year and 53%, 70%, and 74% at 5 years, respectively. Conclusions: Long-term secondary patency rates justify SVC grafting for benign disease. Postoperative surveillance with contrast venography is indicated in the first year to detect graft problems. Endovascular techniques may salvage and improve the patency of SVC grafts. (J Vasc Surg 1998;27:287-301.

Satellite Solar Insolation-Based Daily Evapotranspiration Estimation in Puerto Rico

ABSTRACT: A technique is presented in which satellite solar insolation estimates are used to predict daily reference evapotranspiration (ET o ) using the Penman-Monteith (PM), Preistly-Taylor (PT) and Hargreaves-Samini (HS) methods for Puerto Rico. For this approach, average, minimum and maximum daily air temperatures were obtained from a regression procedure that depends on surface elevation and day of the year. The air temperature was adjusted using actual daily temperatures from several locations in PR. Dew point temperature was assumed to be equal to the daily minimum temperature, and a value of 1.9 m/s was assumed for wind speed. As an example, ET o was estimated for March 5, 2009 using the three methods, with the Penman-Monteith method producing the lowest values. This research represents a preliminary step in the development of an ET o product for PR. This product is a potentially valuable tool for conducting water resource studies and for supporting irrigation scheduling efforts

Long-read sequencing-based in silico phage typing of vancomycin-resistant Enterococcus faecium

Abstract Background Vancomycin-resistant enterococci (VRE) are successful nosocomial pathogens able to cause hospital outbreaks. In the Netherlands, core-genome MLST (cgMLST) based on short-read sequencing is often used for molecular typing. Long-read sequencing is more rapid and provides useful information about the genome’s structural composition but lacks the precision required for SNP-based typing and cgMLST. Here we compared prophages among 50 complete E. faecium genomes belonging to different lineages to explore whether a phage signature would be usable for typing and identifying an outbreak caused by VRE. As a proof of principle, we investigated if long-read sequencing data would allow for identifying phage signatures and thereby outbreak-related isolates. Results Analysis of complete genome sequences of publicly available isolates showed variation in phage content among different lineages defined by MLST. We identified phage present in multiple STs as well as phages uniquely detected within a single lineage. Next, in silico phage typing was applied to twelve MinION sequenced isolates belonging to two different genetic backgrounds, namely ST117/CT24 and ST80/CT16. Genomic comparisons of the long-read-based assemblies allowed us to correctly identify isolates of the same complex type based on global genome architecture and specific phage signature similarity. Conclusions For rapid identification of related VRE isolates, phage content analysis in long-read sequencing data is possible. This allows software development for real-time typing analysis of long-read sequencing data, which will generate results within several hours. Future studies are required to assess the discriminatory power of this method in the investigation of ongoing outbreaks over a longer time period

Contemporary management of acute mesenteric ischemia: Factors associated with survival

AbstractPurpose: Acute mesenteric ischemia (AMI) is a morbid condition with a difficult diagnosis and a high rate of complications, which is associated with a high mortality rate. For the evaluation of the results of current management and the examination of factors associated with survival, we reviewed our experience. Methods: The clinical data of all the patients who underwent operation for AMI between January 1, 1990, and December 31, 1999, were retrospectively reviewed, clinical outcome was recorded, and factors associated with survival rate were analyzed. Results: Fifty-eight patients (22 men and 36 women; mean age, 67 years; age range, 35 to 96 years) underwent study. The cause of AMI was embolism in 16 patients (28%), thrombosis in 37 patients (64%), and nonocclusive mesenteric ischemia (NMI) in five patients (8.6%). Abdominal pain was the most frequent presenting symptom (95%). Twenty-five patients (43%) had previous symptoms of chronic mesenteric ischemia. All the patients underwent abdominal exploration, preceded with arteriography in 47 (81%) and with endovascular treatment in eight. Open mesenteric revascularization was performed in 43 patients (bypass grafting, n = 22; thromboembolectomy, n = 19; patch angioplasty, n = 11; endarterectomy, n = 5; reimplantation, n = 2). Thirty-one patients (53%) needed bowel resection at the first operation. Twenty-three patients underwent second-look procedures, 11 patients underwent bowel resections (repeat resection, n = 9), and three patients underwent exploration only. The 30-day mortality rate was 32%. The rate was 31% in patients with embolism, 32% in patients with thrombosis, and 80% in patients with NMI. Multiorgan failure (n = 18 patients) was the most frequent cause of death. The cumulative survival rates at 90 days, at 1 year, and at 3 years were 59%, 43%, and 32%, respectively, which was lower than the rate of a Midwestern white control population (P <.001). Six of the 16 late deaths (38%) occurred because of complications of mesenteric ischemia. Age less than 60 years (P <.003) and bowel resection (P =.03) were associated with improved survival rates. Conclusion: The contemporary management of AMI with revascularization with open surgical techniques, resection of nonviable bowel, and liberal use of second-look procedures results in the early survival of two thirds of the patients with embolism and thrombosis. Older patients, those who did not undergo bowel resection, and those with NMI have the highest mortality rates. The long-term survival rate remains dismal. Timely revascularization in patients who are symptomatic with chronic mesenteric ischemia should be considered to decrease the high mortality rate of AMI. (J Vasc Surg 2002;35:445-52.

High Interlaboratory Reproducibility and Accuracy of Next-Generation-Sequencing- Based Bacterial Genotyping in a Ring Trial

Today, next-generation whole-genome sequencing (WGS) is increasingly used to determine the genetic relationships of bacteria on a nearly whole-genome level for infection control purposes and molecular surveillance. Here, we conducted a multicenter ring trial comprising five laboratories to determine the reproducibility and accuracy of WGS-based typing. The participating laboratories sequenced 20 blind-coded Staphylococcus aureus DNA samples using 250-bp paired-end chemistry for library preparation in a single sequencing run on an Illumina MiSeq sequencer. The run acceptance criteria were sequencing outputs >5.6 Gb and Q30 read quality scores of > 75%. Subsequently, spa typing, multilocus sequence typing (MLST), ribosomal MLST, and core genome MLST (cgMLST) were performed by the participants. Moreover, discrepancies in cgMLST target sequences in comparisons with the included and also published sequence of the quality control strain ATCC 25923 were resolved using Sanger sequencing. All five laboratories fulfilled the run acceptance criteria in a single sequencing run without any repetition. Of the 400 total possible typing results, 394 of the reported spa types, sequence types (STs), ribosomal STs (rSTs), and cgMLST cluster types were correct and identical among all laboratories; only six typing results were missing. An analysis of cgMLST allelic profiles corroborated this high reproducibility; only 3 of 183,927 (0.0016%) cgMLST allele calls were wrong. Sanger sequencing confirmed all 12 discrepancies of the ring trial results in comparison with the published sequence of ATCC 25923. In summary, this ring trial demonstrated the high reproducibility and accuracy of current next-generation sequencing-based bacterial typing for molecular surveillance when done with nearly completely locked-down methods

Impact of digestive and oropharyngeal decontamination on the intestinal microbiota in ICU patients

Selective digestive microbial decontamination (SDD) is hypothesized to benefit patients in intensive care (ICU) by suppressing Gram-negative potential pathogens from the colon without affecting the anaerobic intestinal microbiota. The purpose of this study was to provide more insight to the effects of digestive tract and oropharyngeal decontamination on the intestinal microbiota by means of a prospective clinical trial in which faecal samples were collected from ICU patients for intestinal microbiota analysis. The faecal samples were collected from ICU patients enrolled in a multicentre trial to study the outcome of SDD and selective oral decontamination (SOD) in comparison with standard care (SC). Fluorescent in situ hybridization (FISH) was used to analyze the faecal microbiota. The numbers of bacteria from different bacterial groups were compared between the three regimens. The total counts of bacteria per gram faeces did not differ between regimens. The F. prausnitzii group of bacteria, representing an important group among intestinal microbiota, was significantly reduced in the SDD regimen compared to the SC and SOD. The Enterobacteriaceae were significantly suppressed during SDD compared to both SOD and SC; enterococci increased in SDD compared to both other regimens. The composition of the intestinal microbiota is importantly affected by SDD. The F. prausnitzii group was significantly suppressed during SDD. This group of microbiota is a predominant producer of butyrate, the main energy source for colonocytes. Reduction of this microbiota is an important trade-off while reducing gram-negative bacteria by SDD

Rapid translocation of nanoparticles from the lung airspaces to the body

Nano-size particles show promise for pulmonary drug delivery, yet their behavior after deposition in the lung remains poorly understood. In this study, a series of near-infrared (NIR) fluorescent nanoparticles were systematically varied in chemical composition, shape, size and surface charge, and their biodistribution and elimination were quantified in rat models after lung instillation. We demonstrate that nanoparticles with hydrodynamic diameter (HD) less than ≈34 nm and a noncationic surface charge translocate rapidly from the lung to mediastinal lymph nodes. Nanoparticles of HD < 6 nm can traffic rapidly from the lungs to lymph nodes and the bloodstream, and then be subsequently cleared by the kidneys. We discuss the importance of these findings for drug delivery, air pollution and carcinogenesis