Implementation of Virtual Interactive Cases for Pharmacy Education: A Single-Center Experience.

Patient case simulation software are described in pharmacy education literature as useful tools to improve skills in patient assessment (including medication history-taking and physical assessment), clinical reasoning and communication, and are typically well-received by students and instructors. The virtual interactive case (VIC) system is a web-based software developed to deliver deliberate practice opportunities in simulated patient encounters across a spectrum of clinical topics. This article describes the implementation and utilization of VIC in the undergraduate curriculum at one Canadian pharmacy school. Methods: At our facility, the use of VIC was integrated across the training spectrum in the curriculum, including core and elective didactic courses and practice labs, experiential learning, interprofessional education, and continuing education. Its use was evaluated through student and instructor surveys and qualitative student interviews). VIC is easy to navigate and created a positive and realistic learning environment. Students identified that it enhanced their ability to identify relevant patient information, accurately simulated hospital pharmacy practice and thereby helped them to prepare for their upcoming experiential courses. The use of VIC has expanded beyond its original intended purpose for individual student practice to become a valuable addition to pharmacy undergraduate education. Future plans include ongoing development of cases and exploration of further uses of VIC within the didactic curriculum, for remediation in experiential courses, and for pharmacist continuing education.

Pharmacy student contribution to direct patient care during inpatient hospital experiential rotations: a scoping review.

OBJECTIVES: The aim of this scoping review was to identify and characterise pharmacy students' contributions to extend pharmacist's direct patient care during inpatient hospital experiential rotations. METHODS: A search of PubMed, Embase and CINAHL databases from 2000 to July 2021 was conducted. Articles were included if they involved pharmacy students during experiential rotations, described student's contribution to direct patient care in the inpatient hospital setting, and reported outcomes. Included articles were categorised according to clinical pharmacy key performance indicators (cpKPIs) and non-cpKPI care activities. Students' contributions to reported outcomes were extracted and summarised. KEY FINDINGS: Thirty-six of 1182 identified articles were included which were either descriptive or quasi-experimental design. Studies reported student involvement in the delivery of single or multiple cpKPIs: medication reconciliation on admission (n = 13), pharmaceutical care (n = 13), interprofessional care rounds (n = 4), patient education during hospital stay (n = 6), medication reconciliation at discharge (n = 7) and patient education at discharge (n = 10). Eight studies reported student involvement in non-cpKPI activities, including clinical interventions (n = 5), clinical services (n = 2) and postdischarge follow-up (n = 1). Reported outcomes included service measure counts, process and clinical outcome measures. SUMMARY: This review identified the contributions of pharmacy students in the provision of a range of direct patient care services and associated outcomes during experiential rotations in the inpatient hospital setting. Students delivering care as part of the pharmacy team as 'care extenders' has the potential to expose more patients to key pharmacist activities that have been linked to demonstrated positive outcomes.

Catchment characteristics and seasonality control the composition of microbial assemblages exported from three outlet glaciers of the Greenland Ice Sheet.

Glacial meltwater drains into proglacial rivers where it interacts with the surrounding landscape, collecting microbial cells as it travels downstream. Characterizing the composition of the resulting microbial assemblages in transport can inform us about intra-annual changes in meltwater flowpaths beneath the glacier as well as hydrological connectivity with proglacial areas. Here, we investigated how the structure of suspended microbial assemblages evolves over the course of a melt season for three proglacial catchments of the Greenland Ice Sheet (GrIS), reasoning that differences in glacier size and the proportion of glacierized versus non-glacierized catchment areas will influence both the identity and relative abundance of microbial taxa in transport. Streamwater samples were taken at the same time each day over a period of 3 weeks (summer 2018) to identify temporal patterns in microbial assemblages for three outlet glaciers of the GrIS, which differed in glacier size (smallest to largest; Russell, Leverett, and Isunnguata Sermia [IS]) and their glacierized: proglacial catchment area ratio (Leverett, 76; Isunnguata Sermia, 25; Russell, 2). DNA was extracted from samples, and 16S rRNA gene amplicons sequenced to characterize the structure of assemblages. We found that microbial diversity was significantly greater in Isunnguata Sermia and Russell Glacier rivers compared to Leverett Glacier, the latter of which having the smallest relative proglacial catchment area. Furthermore, the microbial diversity of the former two catchments continued to increase over monitored period, presumably due to increasing hydrologic connectivity with proglacial habitats. Meanwhile, diversity decreased over the monitored period in Leverett, which may have resulted from the evolution of an efficient subglacial drainage system. Linear discriminant analysis further revealed that bacteria characteristic to soils were disproportionately represented in the Isunnguata Sermia river, while putative methylotrophs were disproportionately abundant in Russell Glacier. Meanwhile, taxa typical for glacierized habitats (i.e., Rhodoferax and Polaromonas) dominated in the Leverett Glacier river. Our findings suggest that the proportion of deglaciated catchment area is more influential to suspended microbial assemblage structure than absolute glacier size, and improve our understanding of hydrological flowpaths, particulate entrainment, and transport.

Student readiness to apply pharmacotherapy concepts to institutional early practice experience - a pilot study.

INTRODUCTION: In order to gain exposure to hospital practice earlier in the education of doctor of pharmacy students, a recent curricular change by the faculty of pharmacy prioritized institutional sites for year two early practice experiences (EPE2s). The goal of this study was to assess whether year two student pharmacists were adequately equipped by the faculty to apply clinical concepts when providing direct patient care in an institutional setting. METHODS: At the study institution, four students rated the relevancy of clinical concepts covered in five pharmacotherapy courses to their EPE2 practice using a relevance score tool. Students self-evaluated their ability-to-practice (AP) these concepts at the start and end of the rotation using an AP score tool. RESULTS: The students determined that all pharmacotherapy courses covered at least one clinical concept that was occasionally seen and applied to practice at the study institution, except for dermatology/ears, eyes, nose, and throat. All AP scores for relevant clinical concepts improved post-rotation except for dyslipidemia, which remained unchanged. CONCLUSIONS: The year two students who participated in the pilot study had sufficient knowledge to apply pharmacotherapy concepts when performing supervised direct patient care at the study institution.

An analysis of Canadian doctor of pharmacy hospital preceptor experiences in alternative preceptor models.

OBJECTIVE: To describe pharmacy preceptors' experiences in alternative preceptor models and their perceptions of these models' impact on the knowledge, skills, attitudes, behaviors, and professional practices of both themselves and their students. METHODS: Pharmacy preceptors with experience using alternative preceptor models participated in semi-structured interviews. Models included peer-assisted learning (PAL) (≥ two students of the same educational level), near-peer teaching (NPT) (≥ one junior student with ≥ one senior student), and co-preceptorship (CoP) (≥ two preceptors). Interviews were transcribed, coded, and analyzed for themes using the Kirkpatrick framework for evaluating educational interventions. RESULTS: Twenty hospital pharmacy preceptors from 13 institutions were interviewed, and 13 themes were identified. Fourteen preceptors had experience with PAL, 9 with NPT, and 9 with CoP. Preceptors perceived that NPT and PAL fostered comfortable learning environments that supported student success; challenges included increased time teaching multiple students and completing evaluations. CoP allowed preceptors to balance teaching with clinical duties while broadening students' exposure to different practice settings. Preceptors improved skills in time management, communicating feedback, and adapting to individual students' learning needs and styles. Alternative models enabled preceptors to provide care to more patients and complete projects, thus extending their professional practice. They also described that students participating in these models developed a sense of responsibility for patient care and will be primed to work collaboratively with pharmacy colleagues in the future. CONCLUSIONS: Preceptors expressed satisfaction with alternative preceptor models. The models enhanced the learning, skill development, and professional practice of both preceptors and students.

Patterns in Microbial Assemblages Exported From the Meltwater of Arctic and Sub-Arctic Glaciers.

Meltwater streams connect the glacial cryosphere with downstream ecosystems. Dissolved and particulate matter exported from glacial ecosystems originates from contrasting supraglacial and subglacial environments, and exported microbial cells have the potential to serve as ecological and hydrological indicators for glacial ecosystem processes. Here, we compare exported microbial assemblages from the meltwater of 24 glaciers from six (sub)Arctic regions - the southwestern Greenland Ice Sheet, Qeqertarsuaq (Disko Island) in west Greenland, Iceland, Svalbard, western Norway, and southeast Alaska - differing in their lithology, catchment size, and climatic characteristics, to investigate spatial and environmental factors structuring exported meltwater assemblages. We found that 16S rRNA gene sequences of all samples were dominated by the phyla Proteobacteria, Bacteroidetes, and Actinobacteria, with Verrucomicrobia also common in Greenland localities. Clustered OTUs were largely composed of aerobic and anaerobic heterotrophs capable of degrading a wide variety of carbon substrates. A small number of OTUs dominated all assemblages, with the most abundant being from the genera Polaromonas, Methylophilus, and Nitrotoga. However, 16-32% of a region's OTUs were unique to that region, and rare taxa revealed unique metabolic potentials and reflected differences between regions, such as the elevated relative abundances of sulfur oxidizers Sulfuricurvum sp. and Thiobacillus sp. at Svalbard sites. Meltwater alpha diversity showed a pronounced decrease with increasing latitude, and multivariate analyses of assemblages revealed significant regional clusters. Distance-based redundancy and correlation analyses further resolved associations between whole assemblages and individual OTUs with variables primarily corresponding with the sampled regions. Interestingly, some OTUs indicating specific metabolic processes were not strongly associated with corresponding meltwater characteristics (e.g., nitrification and inorganic nitrogen concentrations). Thus, while exported assemblage structure appears regionally specific, and probably reflects differences in dominant hydrological flowpaths, OTUs can also serve as indicators for more localized microbially mediated processes not captured by the traditional characterization of bulk meltwater hydrochemistry. These results collectively promote a better understanding of microbial distributions across the Arctic, as well as linkages between the terrestrial cryosphere habitats and downstream ecosystems.

Glacial microbiota are hydrologically connected and temporally variable.

Glaciers are melting rapidly. The concurrent export of microbial assemblages alongside glacial meltwater is expected to impact the ecology of adjoining ecosystems. Currently, the source of exported assemblages is poorly understood, yet this information may be critical for understanding how current and future glacial melt seasons may influence downstream environments. We report on the connectivity and temporal variability of microbiota sampled from supraglacial, subglacial and periglacial habitats and water bodies within a glacial catchment. Sampled assemblages showed evidence of being biologically connected through hydrological flowpaths, leading to a meltwater system that accumulates prokaryotic biota as it travels downstream. Temporal changes in the connected assemblages were similarly observed. Snow assemblages changed markedly throughout the sample period, likely reflecting changes in the surrounding environment. Changes in supraglacial meltwater assemblages reflected the transition of the glacial surface from snow-covered to bare-ice. Marked snowmelt across the surrounding periglacial environment resulted in the flushing of soil assemblages into the riverine system. In contrast, surface ice within the ablation zone and subglacial meltwaters remained relatively stable throughout the sample period. Our results are indicative that changes in snow and ice melt across glacial environments will influence the abundance and diversity of microbial assemblages transported downstream.

Microbial genomics amidst the Arctic crisis.

The Arctic is warming - fast. Microbes in the Arctic play pivotal roles in feedbacks that magnify the impacts of Arctic change. Understanding the genome evolution, diversity and dynamics of Arctic microbes can provide insights relevant for both fundamental microbiology and interdisciplinary Arctic science. Within this synthesis, we highlight four key areas where genomic insights to the microbial dimensions of Arctic change are urgently required: the changing Arctic Ocean, greenhouse gas release from the thawing permafrost, 'biological darkening' of glacial surfaces, and human activities within the Arctic. Furthermore, we identify four principal challenges that provide opportunities for timely innovation in Arctic microbial genomics. These range from insufficient genomic data to develop unifying concepts or model organisms for Arctic microbiology to challenges in gaining authentic insights to the structure and function of low-biomass microbiota and integration of data on the causes and consequences of microbial feedbacks across scales. We contend that our insights to date on the genomics of Arctic microbes are limited in these key areas, and we identify priorities and new ways of working to help ensure microbial genomics is in the vanguard of the scientific response to the Arctic crisis.

A developmental evaluation of an intraprofessional Pharmacy Communication Partnership (PROMPT) to improve transitions in care from hospital to community: A mixed-methods study.

BACKGROUND: People transitioning from hospital- to community-based care are at increased risk of experiencing medication problems that can lead to adverse drug events and poor health outcomes. Community pharmacists provide medication expertise and support during care transitions yet are not routinely included in communications between hospitals and other primary health care providers. The PhaRmacy COMmunication ParTnership (PROMPT) intervention facilitates medication management by optimizing information sharing between pharmacists across care settings. This developmental evaluation sought to assess the feasibility and acceptability of implementing the PROMPT intervention, and to explore how contextual factors influenced its implementation. METHODS: PROMPT was implemented for 14 weeks (January-April, 2018) in the general internal medicine units at two teaching hospitals in Toronto, Canada. PROMPT featured two contact points between hospital and community pharmacists around patient discharge: (1) faxing an enhanced discharge prescription and discharge summary to a patient's community pharmacy and (2) a follow-up phone call from the hospital pharmacist to the community pharmacist. Our mixed-method evaluation involved electronic patient records, process measures using tracking forms, telephone surveys and semi-structured interviews with participating community and hospital pharmacists. RESULTS: The intervention involved 45 patients with communication between 12 hospital and 45 community pharmacists. Overall, the intervention had challenges with feasibility. Issues with fidelity included challenges with the medical discharge summary being available at the time of faxing and hospital pharmacists' difficulties with incorporating novel elements of the program into their existing practices. However, both community and hospital pharmacists recognized the potential benefits to patient care that PROMPT offered, and both groups proposed recommendations for further improvements. Suggestions included enhancing hospital staffing and resources. CONCLUSION: Improving intraprofessional collaboration, through interventions such as PROMPT, positions pharmacists as leaders of medication management services across care settings and has the potential to improve patient care; however, more co-design work is needed to enhance the intervention and its fidelity.

Illuminating the dynamic rare biosphere of the Greenland Ice Sheet's Dark Zone.

Greenland's Dark Zone is the largest contiguous region of bare terrestrial ice in the Northern Hemisphere and microbial processes play an important role in driving its darkening and thereby amplifying melt and runoff from the ice sheet. However, the dynamics of these microbiota have not been fully identified. Here, we present joint 16S rRNA gene and 16S rRNA (cDNA) comparison of input (snow), storage (cryoconite) and output (supraglacial stream water) habitats across the Dark Zone over the melt season. We reveal that all three Dark Zone communities have a preponderance of rare taxa exhibiting high protein synthesis potential (PSP). Furthermore, taxa with high PSP represent highly connected 'bottlenecks' within community structure, consistent with their roles as metabolic hubs. Finally, low abundance-high PSP taxa affiliated with Methylobacterium within snow and stream water suggest a novel role for Methylobacterium in the carbon cycle of Greenlandic snowpacks, and importantly, the export of potentially active methylotrophs to the bed of the Greenland Ice Sheet. By comparing the dynamics of bulk and potentially active microbiota in the Dark Zone of the Greenland Ice Sheet, we provide novel insights into the mechanisms and impacts of the microbial colonization of this critical region of our melting planet.

Glacier Algae: A Dark Past and a Darker Future.

"Glacier algae" grow on melting glacier and ice sheet surfaces across the cryosphere, causing the ice to absorb more solar energy and consequently melt faster, while also turning over carbon and nutrients. This makes glacier algal assemblages, which are typically dominated by just three main species, a potentially important yet under-researched component of the global biosphere, carbon, and water cycles. This review synthesizes current knowledge on glacier algae phylogenetics, physiology, and ecology. We discuss their significance for the evolution of early land plants and highlight their impacts on the physical and chemical supraglacial environment including their role as drivers of positive feedbacks to climate warming, thereby demonstrating their influence on Earth's past and future. Four complementary research priorities are identified, which will facilitate broad advances in glacier algae research, including establishment of reliable culture collections, sequencing of glacier algae genomes, development of diagnostic biosignatures for remote sensing, and improved predictive modeling of glacier algae biological-albedo effects.

Descriptive Analysis of Pharmacy Students' Impressions on Virtual Interactive Case Software.

Objective. To assess students' impressions on whether Virtual Interactive Cases (VICs) contribute to their learning experience. Methods. Ten fourth- year pharmacy students each independently completed the same four VICs followed by a semi-structured interview conducted by VIC project team members. The interviews were audio-recorded, transcribed, and coded for themes using qualitative research methods. Results. All participating students completed all the cases. Overall, students' feedback on VIC was positive. Five main themes emerged from the transcripts: VIC facilitated their skills in information gathering; they learned from the built-in, real-time, formative feedback; they had a fun and positive learning experience; VICs were realistic; and VIC system was user-friendly. Students also recommended that VIC be incorporated into classroom learning. Some students required additional explanation on the concept of time and costs associated with each action they selected, and the associated performance score. Conclusion. Pharmacy students' positive experiences with VICs support its use to bridge classroom learning with clinical practice.

A systematic review of direct oral anticoagulant use in chronic kidney disease and dialysis patients with atrial fibrillation.

Background: There is a lack of clear benefit and a potential risk of bleeding with direct oral anticoagulant (DOAC) use in chronic kidney disease (CKD) and dialysis patients with atrial fibrillation. The objective of this study was to evaluate how treatment with DOACs affects stroke and bleeding outcomes compared with warfarin or aspirin. Methods: We conducted a systematic review of randomized controlled trials, cohort studies and case series, and searched electronic databases from 1946 to 2017. Studies evaluating stroke and bleeding outcomes with DOAC use in CKD and dialysis patients were included. Results: From 8008 studies, 10 met the inclusion criteria. For moderate CKD patients (estimated glomerular filtration rate <60 mL/min/1.73 m2), there was no difference in stroke outcomes between dabigatran 110 mg [hazard ratio (HR) 0.78, 95% confidence interval (95% CI) 0.51-1.21], rivaroxaban (HR 0.82-0.84, 95% CI 0.25-2.69) and edoxaban (HR 0.87, 95% CI 0.65-1.18) versus warfarin. Dabigatran (150 mg twice daily) and apixaban reduced risk of stroke or systemic embolism significantly more than warfarin for moderate CKD patients (HR 0.55, 95% CI 0.34-0.89 and HR 0.61, 95% CI 0.39-0.94, respectively). Edoxaban and apixaban were associated with reduced major bleeding events (HR 0.50-0.76) compared with warfarin. Rivaroxaban and dabigatran 110 mg and 150 mg showed no significant difference in major bleeding versus warfarin. In hemodialysis (HD) patients, there was no difference in stroke outcomes between apixaban, dabigatran [relative risk (RR) 1.71, 95% CI 0.97-2.99] or rivaroxaban (RR 1.8, 95% CI 0.89-3.64) versus warfarin. In HD patients, rivaroxaban and dabigatran were associated with an increased major bleeding risk (RR 1.45-1.76), whereas there was no major bleeding difference with apixaban compared to warfarin. Limitations: The heterogeneity of major bleeding and stroke definitions of the 10 included studies. Conclusions: Clinicians should continue to weigh the risk of stroke versus bleeding before prescribing DOACs in the CKD and dialysis population.

An Analysis of Canadian Doctor of Pharmacy Student Experiences in Non-Traditional Student-Preceptor Models.

Objective. To describe students' experiences and perceptions of non-traditional student-preceptor learning models and evaluate the effectiveness of these models on students' learning experience. Methods. Pharmacy students who had completed at least one experiential rotation with a non-traditional learning model participated in semi-structured interviews. Models included peer-assisted learning (PAL; two or more students of same educational level), near-peer teaching (NPT; one or more junior students with one or more senior students), and co-preceptorship (CoP; two or more preceptors). Interviews were transcribed, coded, and analyzed for themes. Themes were mapped according to the Kirkpatrick model for evaluating educational training. Results. Twenty semi-structured interviews were conducted. Forty-three experiences (19 CoP, 14 PAL, 10 NPT) from 14 institutions were described. Many themes overlapped between the three models. In CoP, learners described increased preceptor availability and exposure to different patient care approaches. Challenges arose when preceptors had different expectations. Students overwhelmingly endorsed a multi-learner environment. Both PAL and NPT learners felt supported as collaboration with other learners was readily fostered. Potential challenges in PAL and NPT were difficulties when personalities conflicted and when there was a significant knowledge gap between the learners. All three models allowed for the development of skills, including communication and collaboration. Learners reported an enhanced approach to patient care and professional practice, including approaches to teaching as new preceptors. Conclusion. Pharmacy students and graduates valued their experiences in non-traditional student-preceptor models. Institutions may find support for using these precepting models to increase placement capacity.

Enhanced communication between inpatient and community pharmacists to optimize medication management during transitions of care.

OBJECTIVES: To describe the Pharmacy Communication Partnership (PROMPT) program's approach to improving medication management for patients during transitions from hospital to the community. SETTING: Two general internal medicine units within a multisite academic hospital in Canada. PRACTICE INNOVATION: Designed by an interprofessional working group, PROMPT uses evidence-informed approaches to facilitate communication between pharmacists in different settings: faxing of the discharge prescription and medical discharge summary to a patient's community pharmacy, followed by a telephone call to the community pharmacist. EVALUATION: A multimethod cross-sectional study used telephone surveys and retrospective chart reviews to describe: 1) the characteristics of patients that hospital pharmacists thought would benefit from PROMPT and the community pharmacies that served them; 2) the number and nature of communication attempts made by community and hospital pharmacists; and 3) community pharmacists' views about PROMPT's potential impact on continuity of care and potential program enhancements. RESULTS: A convenience sample of 100 patients (median age 77 years, interquartile range 66 to 83) who received care from 86 pharmacies were used to evaluate the program. The majority of community pharmacists participating in the surveys considered the intervention to be helpful. Of the 53.7% (n = 44/82) community pharmacists who received discharge summaries, 93.2% (n = 41/44) found the summaries to be useful. Themes arising from community pharmacists' comments were categorized into 3 topics: 1) the benefits of PROMPT; 2) topics of discussion and clarification during telephone calls with hospital pharmacists; and 3) future program improvements. CONCLUSION: Community pharmacists described PROMPT as a time-efficient and helpful bridge linking community pharmacy to hospital inpatient care. Opportunities for future research include determining the characteristics of patients who may benefit most from PROMPT, determining the optimal components of discharge information needed by community pharmacists to enhance medication management, and evaluating whether follow-up telephone calls from the hospital to community pharmacists are necessary for all patients.

Dark zone of the Greenland Ice Sheet controlled by distributed biologically-active impurities.

Albedo-a primary control on surface melt-varies considerably across the Greenland Ice Sheet yet the specific surface types that comprise its dark zone remain unquantified. Here we use UAV imagery to attribute seven distinct surface types to observed albedo along a 25 km transect dissecting the western, ablating sector of the ice sheet. Our results demonstrate that distributed surface impurities-an admixture of dust, black carbon and pigmented algae-explain 73% of the observed spatial variability in albedo and are responsible for the dark zone itself. Crevassing and supraglacial water also drive albedo reduction but due to their limited extent, explain just 12 and 15% of the observed variability respectively. Cryoconite, concentrated in large holes or fluvial deposits, is the darkest surface type but accounts for <1% of the area and has minimal impact. We propose that the ongoing emergence and dispersal of distributed impurities, amplified by enhanced ablation and biological activity, will drive future expansion of Greenland's dark zone.

Potential Activity of Subglacial Microbiota Transported to Anoxic River Delta Sediments.

The Watson River drains a portion of the SW Greenland ice sheet, transporting microbial communities from subglacial environments to a delta at the head of Søndre Strømfjord. This study investigates the potential activity and community shifts of glacial microbiota deposited and buried under layers of sediments within the river delta. A long-term (12-month) incubation experiment was established using Watson River delta sediment under anaerobic conditions, with and without CO2/H2 enrichment. Within CO2/H2-amended incubations, sulphate depletion and a shift in the microbial community to a 52% predominance of Desulfosporosinus meridiei by day 371 provides evidence for sulphate reduction. We found evidence of methanogenesis in CO2/H2-amended incubations within the first 5 months, with production rates of ~4 pmol g-1 d-1, which was likely performed by methanogenic Methanomicrobiales- and Methanosarcinales-related organisms. Later, a reduction in methane was observed to be paired with the depletion of sulphate, and we hypothesise that sulphate reduction out competed hydrogenotrophic methanogenesis. The structure and diversity of the original CO2/H2-amended incubation communities changed dramatically with a major shift in predominant community members and a decline in diversity and cell abundance. These results highlight the need for further investigations into the fate of subglacial microbiota within downstream environments.

Nitrate addition has minimal short-term impacts on greenland ice sheet supraglacial prokaryotes.

Tropospheric nitrate levels are predicted to increase throughout the 21st century, with potential effects on terrestrial ecosystems, including the Greenland ice sheet (GrIS). This study considers the impacts of elevated nitrate concentrations on the abundance and composition of dominant bulk and active prokaryotic communities sampled from in situ nitrate fertilization plots on the GrIS surface. Nitrate concentrations were successfully elevated within sediment-filled meltwater pools, known as cryoconite holes; however, nitrate additions applied to surface ice did not persist. Estimated bulk and active cryoconite community cell abundance was unaltered by nitrate additions when compared to control holes using a quantitative PCR approach, and nitrate was found to have a minimal affect on the dominant 16S rRNA gene-based community composition. Together, these results indicate that sampled cryoconite communities were not nitrate limited at the time of sampling. Instead, temporal changes in biomass and community composition were more pronounced. As these in situ incubations were short (6 weeks), and the community composition across GrIS surface ice is highly variable, we suggest that further efforts should be considered to investigate the potential long-term impacts of increased nitrate across the GrIS.

Meltwater export of prokaryotic cells from the Greenland ice sheet.

Microorganisms are flushed from the Greenland Ice Sheet (GrIS) where they may contribute towards the nutrient cycling and community compositions of downstream ecosystems. We investigate meltwater microbial assemblages as they exit the GrIS from a large outlet glacier, and as they enter a downstream river delta during the record melt year of 2012. Prokaryotic abundance, flux and community composition was studied, and factors affecting community structures were statistically considered. The mean concentration of cells exiting the ice sheet was 8.30 × 104 cells mL-1 and we estimate that ∼1.02 × 1021 cells were transported to the downstream fjord in 2012, equivalent to 30.95 Mg of carbon. Prokaryotic microbial assemblages were dominated by Proteobacteria, Bacteroidetes, and Actinobacteria. Cell concentrations and community compositions were stable throughout the sample period, and were statistically similar at both sample sites. Based on our observations, we argue that the subglacial environment is the primary source of the river-transported microbiota, and that cell export from the GrIS is dependent on discharge. We hypothesise that the release of subglacial microbiota to downstream ecosystems will increase as freshwater flux from the GrIS rises in a warming world.