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1.
BMJ Paediatr Open ; 8(1)2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38663937

ABSTRACT

OBJECTIVE: The UK falls behind other European countries in the early detection of developmental dysplasia of the hip (DDH) and screening strategies differ for early detection. Clinical detection of DDH is challenging and recognised to be dependent on examiner experience. No studies exist assessing the number of personnel currently involved in such assessments.Our objective was to review the current screening procedure by studying a cohort of newborn babies in one teaching hospital and assess the number of health professionals involved in neonatal hip assessment and the number of examinations undertaken during one period by each individual. METHODS: This was a retrospective observational study assessing all babies born consecutively over a 14-week period in 2020. Record of each initial baby check was obtained from BadgerNet. Follow-up data on ultrasound or orthopaedic outpatient referrals were obtained from clinical records. RESULTS: 1037 babies were examined by 65 individual examiners representing 9 different healthcare professional groups. The range of examinations conducted per examiner was 1-97 with a median of 5.5 examinations per person. 49% of individuals examined 5 or less babies across the 14 weeks, with 18% only performing 1 examination. Of the six babies (0.48%) treated for DDH, one was picked up on neonatal assessment. CONCLUSION: In a system where so many examiners are involved in neonatal hip assessment, the experience is limited for most examiners. Currently high rates of late presentation of DDH are observed locally, which are in accordance with published national experience. The potential association merits further investigation.


Subject(s)
Neonatal Screening , Humans , Infant, Newborn , Retrospective Studies , Neonatal Screening/methods , Hip Dislocation, Congenital/diagnosis , Hip Dislocation, Congenital/epidemiology , Female , Developmental Dysplasia of the Hip/diagnosis , United Kingdom/epidemiology , Male , Physical Examination/methods , Early Diagnosis
3.
Med J Aust ; 219(3): 105-106, 2023 08 07.
Article in English | MEDLINE | ID: mdl-37414739
4.
BMC Health Serv Res ; 23(1): 616, 2023 Jun 12.
Article in English | MEDLINE | ID: mdl-37308996

ABSTRACT

BACKGROUND: High-frequency hospital users often present with chronic and complex health conditions and are at increased risk of serious morbidity and mortality if they contract COVID-19. Understanding where high-frequency hospital users are sourcing their information, whether they understand what they find, and how they apply the information to prevent the spread of COVID-19 is essential for health authorities to be able to target communication approaches. METHODS: Cross-sectional survey of 200 frequent hospital users (115 with limited English proficiency) informed by the WHO's "Rapid, simple, flexible behavioral insights on COVID-19". Outcome measures were source of, and trust in information, and knowledge of symptoms, preventive strategies, restrictions, and identification of misinformation. RESULTS: The most frequently cited source of information was television (n = 144, 72%) followed by the internet (n = 84, 42%). One in four television users sought their information from overseas news outlets from their country of origin, while for those using the internet, 56% relied on Facebook and other forms of social media including YouTube and WeChat. Overall, 41.2% of those surveyed had inadequate knowledge about symptoms, 35.8% had inadequate knowledge about preventative strategies, 30.2% had inadequate knowledge about government-imposed restrictions, and 69% believed in misinformation. Half of the respondents (50%) trusted all information, and only one in five (20%) were uncertain or untrusting. English-speaking participants were almost three times more likely to have adequate knowledge about symptoms (OR 2.69, 95%CI 1.47;4.91) and imposed restrictions (OR 2.10 95%CI 1.06; 4.19), and 11 times more likely to recognize misinformation (OR 11.52 95%CI 5.39; 24.60) than those with limited English. CONCLUSION: Within this population of high-frequency hospital users with complex and chronic conditions, many were sourcing their information from less trustworthy or locally relevant sources, including social media and overseas news outlets. Despite this, at least half were trusting all the information that they found. Speaking a language other than English was a much greater risk factor for having inadequate knowledge about COVID-19 and believing in misinformation. Health authorities must look for methods to engage diverse communities, and tailor health messaging and education in order to reduce disparities in health outcomes.


Subject(s)
COVID-19 , Humans , Cross-Sectional Studies , Communication , Language , Hospitals
5.
Ann Gastroenterol ; 36(1): 81-86, 2023.
Article in English | MEDLINE | ID: mdl-36593816

ABSTRACT

Background: We present our experience and established management strategy for endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) in diagnosing suspected pancreatic neoplasms at a tertiary referral cancer hospital. Method: Relevant data were extracted from our database for patients who underwent EUS-FNA for suspected pancreatic neoplasms at our institution between 2007 and 2016. Results: Among the 309 patients, the median age was 67 years and 56% were men. The most common presenting symptoms were abdominal pain (37%) and jaundice (29%). Concordance between radiographic diagnosis and final pathology was 89%. The mean lesion size was 34.9 mm on computed tomography and 31.5 mm on EUS. There were 197 patients (64%) with localized disease, of whom 115 (58%) had resectable lesions, 61 (31%) had borderline resectable, and 21 (11%) had unresectable lesions (mean CA 19-9 levels 1705 U/mL, 2490 U/mL, and 479 U/mL, respectively). A median of 3 FNA passes were performed to establish a pathologic diagnosis. Two patients (1%) had postprocedural adverse events. Median overall survival was 47 months in those who underwent surgery after EUS and 12 months in those who did not (P<0.001). Conclusions: A multidisciplinary approach is employed for management of suspected pancreatic neoplasm at our tertiary cancer center. A combination of cross-sectional imaging and EUS-FNA serves as a highly effective duo in establishing a tissue diagnosis and staging with a low adverse event rate. Counterintuitively, CA 19-9 is not necessarily higher with resectable lesions than with unresectable lesions, indicating the limitation of CA 19-9 as a pancreatic tumor marker.

6.
Org Lett ; 25(5): 777-781, 2023 Feb 10.
Article in English | MEDLINE | ID: mdl-36701675

ABSTRACT

Ethyl diazepane carboxylate catalyzes the oxy-Cope rearrangement of 4-hydroxy- and 4-alkoxy-1,5-hexadiene-2-carboxaldehydes via iminium ion activation. The resulting intermediate undergoes an intramolecular Michael reaction to furnish cyclopentane-containing products. The reaction proceeds with a range of substrates, including both cyclic and acyclic substrates, and tolerates substitution on the vinyl substituent. Substrates fused on a cycloalkane framework undergo net ring expansion/cyclopentannulation with a high degree of stereocontrol via chairlike transition states. The reaction extends iminium organocatalysis to the oxy-Cope rearrangement, embedded within a complexity-generating cascade transformation.

7.
Surgeon ; 21(1): 31-39, 2023 Feb.
Article in English | MEDLINE | ID: mdl-35292214

ABSTRACT

BACKGROUND: The management of proximal humerus fractures (PHF) in adolescent has not been agreed upon. We aim to investigate the outcomes of PHF managed conservatively in adolescents. METHODS: All shoulder radiographs performed in patients aged from 10 to 18 years and from 2008 to 2015 were reviewed. The radiological parameters, including anatomical side, Neer and Horwitz displacement grade, angulation and any residual deformities were recorded. Mail questionnaires based on the modified 15-Upper Extremities Functional Index (15-UEFI), with a maximum of 59 points, were sent out. The return of the completed anonymized questionnaire was considered as implied consent. RESULTS: 118 patients with a median age of 12 at the time of fracture were identified. The majority of the fractures were Neer and Horwitz grade I displacement and 3 children had Neer and Horwitz grade III and IV displacement. The median angulation was 25°. The median follow-up length was 26 days. 55 patients had residual angulation and 25 patients had worsened angulation. No non-union was identified. No patients underwent subsequent corrective surgeries. 35 patients responded to the questionnaire. The median 15-UEFI was 59 points. None of the patients have contacted the research or clinical team regarding any concerns. CONCLUSION: The vast majority of non-displaced and minimally displaced PHF in adolescent were managed conservatively in our unit. The functional outcomes for this cohort remain excellent even for those with residual deformities in the follow-up radiographs. Further large prospective multicenter studies on adolescent cohort with significantly displaced PHF are warranted.


Subject(s)
Humeral Fractures , Shoulder Fractures , Child , Humans , Adolescent , Fracture Fixation, Internal , Shoulder , Prospective Studies , Shoulder Fractures/diagnostic imaging , Shoulder Fractures/surgery , Scotland , Humeral Fractures/surgery , Treatment Outcome
8.
Gastroenterology Res ; 15(2): 56-66, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35572476

ABSTRACT

Background: Immune checkpoint inhibitors (ICIs) are increasingly used to treat advanced malignancies. However, they are associated with the development of multiple gastrointestinal immune-related adverse events (GI-irAEs). We aimed to evaluate the types and severity of GI-irAEs associated with ICI therapy, to identify potential risk factors for developing GI-irAEs and to determine the relationship of GI-irAEs development to tumor responsiveness and overall survival. Methods: All patients who received ICIs for advanced malignancies at our center were included. Medical records were reviewed, and data extraction included: baseline demographic characteristics, immunotherapy regimens, development of GI-irAEs, response to treatment, and overall survival. Overall survival was calculated from the date of treatment initiation and estimated by the Kaplan-Meier method. Results: Five hundred sixty-seven patients received ICI therapy for stage IV malignancies. Forty-one (7%) patients experienced at least one GI-irAE. Among those experiencing GI-irAEs, 23 (56%) developed hepatitis, 17 (42%) developed colitis, four (10%) developed pancreatitis, and two (5%) developed gastritis. Patients who developed GI-irAEs experienced a better response to ICI therapy compared to patients who did not develop GI-irAEs (41% vs. 27%, P = 0.003). The 2-year overall survival rate of stage IV cancer patients who developed GI-irAEs was 62% (95% confidence interval (CI): 49 - 79) and 36% for those who did not develop GI-irAEs (95% CI: 32 - 41) (P = 0.002). The median follow-up time of surviving patients was 28 months. Twelve (29%) of the patients receiving dual ICI therapy developed GI-irAEs. Conclusion: Hepatitis, colitis, and pancreatitis were the most commonly encountered GI-irAEs with ICI therapy. Development of these GI-irAEs was associated with superior tumor responsiveness and better overall survival.

9.
Lab Anim ; 56(2): 191-195, 2022 Apr.
Article in English | MEDLINE | ID: mdl-34338061

ABSTRACT

Murine translational models are an important tool to understand pain pathophysiology. One procedure used frequently in murine research is the sciatic nerve block. This study sought to demonstrate the use of ultrasound-guided sciatic nerve block in a cadaveric murine model. A total of 40 injections were performed in 20 Sprague-Dawley male 18-month-old rat cadavers. Necropsy was performed to identify staining of the sciatic nerve. Staining with methylene blue occurred in 40 of 40 ultrasound-guided injections. The extremely accurate nature of this block under ultrasound guidance is favorable for future translational studies in rats undergoing sciatic nerve blocks. This method may represent a significant improvement in current methods.


Subject(s)
Nerve Block , Animals , Humans , Injections , Male , Mice , Nerve Block/methods , Rats , Rats, Sprague-Dawley , Sciatic Nerve/diagnostic imaging , Ultrasonography, Interventional/methods
10.
Bioorg Med Chem Lett ; 52: 128327, 2021 11 15.
Article in English | MEDLINE | ID: mdl-34416378

ABSTRACT

Several derivatives of a series that share a thienoisoquinoline scaffold have demonstrated potent activity against cancer cell lines A549, HeLa, HCT-116, and MDA-MB-231 in the submicromolar concentration range. Structure-activity relationship (SAR) studies on a range of derivatives aided in identifying key pharmacophores in the lead compound. A series of compounds have been identified as the most promising with submicromolar IC50 values against a lung cancer cell line (A549). Microscopy studies of cancer cells treated with the lead compound revealed that it causes mitotic arrest and disrupts microtubules. Further evaluation via an in vitro microtubule polymerization assay and competition studies indicate that the lead compound binds to tubulin via the colchicine site.


Subject(s)
Antineoplastic Agents/pharmacology , Drug Design , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , Molecular Structure , Structure-Activity Relationship
11.
Front Med (Lausanne) ; 8: 647834, 2021.
Article in English | MEDLINE | ID: mdl-33898484

ABSTRACT

Biomaterials intentionally designed to support the expansion, differentiation, and three-dimensional (3D) culture of induced-pluripotent stem cells (iPSCs) may pave the way to cell-based therapies for chronic respiratory diseases. These conditions are endured by millions of people worldwide and represent a significant cause of morbidity and mortality. Currently, there are no effective treatments for the majority of advanced lung diseases and lung transplantation remains the only hope for many chronically ill patients. Key opinion leaders speculate that the novel coronavirus, COVID-19, may lead to long-term lung damage, further exacerbating the need for regenerative therapies. New strategies for regenerative cell-based therapies harness the differentiation capability of human iPSCs for studying pulmonary disease pathogenesis and treatment. Excitingly, biomaterials are a cell culture platform that can be precisely designed to direct stem cell differentiation. Here, we present a closer look at the state-of-the-art of iPSC differentiation for pulmonary engineering, offer evidence supporting the power of biomaterials to improve stem cell differentiation, and discuss our perspective on the potential for tissue-informed biomaterials to transform pulmonary regenerative medicine.

12.
World J Clin Cases ; 9(5): 1048-1057, 2021 Feb 16.
Article in English | MEDLINE | ID: mdl-33644168

ABSTRACT

BACKGROUND: Gastrointestinal bleeding (GIB) is a major concern in patients hospitalized with acute coronary syndrome (ACS) due to the common use of both antiplatelet medications and anticoagulants. Studies evaluating the safety of gastrointestinal endoscopy (GIE) in ACS patients with GIB are limited by their relatively small size, and the focus has generally been on upper GIB and esophago-gastroduod-enoscopy (EGD) only. AIM: To evaluate the safety profile and the hospitalization outcomes of undergoing GIE in patients with ACS and concomitant GIB using the national database for hospitalized patients in the United States. METHODS: The Nationwide Inpatient Sample database was queried to identify patients hospitalized with ACS and GIB during the same admission between 2005 and 2014. The International Classification of Diseases Code, 9th Revision Clinical Modification was utilized for patient identification. Patients were further classified into two groups based on undergoing endoscopic procedures (EGD, small intestinal endoscopy, colonoscopy, or flexible sigmoidoscopy). Both groups were compared regarding demographic information, outcomes, and comorbi-dities. Multivariate analysis was conducted to identify factors associated with mortality and prolonged length of stay. Chi-square test was used to compare categorical variables, while Student's t-test was used to compare continuous variables. All analyses were performed using SAS 9.4 (Cary, NC, United States). RESULTS: A total of 35612318 patients with ACS were identified between January 2005 and December 2014. 269483 (0.75%) of the patients diagnosed with ACS developed concomitant GIB during the same admission. At least one endoscopic procedure was performed in 68% of the patients admitted with both ACS and GIB. Patients who underwent GIE during the index hospitalization with ACS and GIB had lower mortality (3.8%) compared to the group not undergoing endoscopy (8.6 %, P < 0.001). A shorter length of stay (LOS) was observed in patients who underwent GIE (mean 6.59 ± 7.81 d) compared to the group not undergoing endoscopy (mean 7.84 ± 9.73 d, P < 0.001). Multivariate analysis showed that performing GIE was associated with lower mortality (odds ratio: 0.58, P < 0.001) and shorter LOS (-0.36 factor, P < 0.001). CONCLUSION: Performing GIE during the index hospitalization of patients with ACS and GIB was correlated with a better mortality rate and a shorter LOS. Approximately two-thirds of patients with both ACS and GIB undergo GIE during the same hospitalization.

13.
J Eval Clin Pract ; 27(2): 228-235, 2021 Apr.
Article in English | MEDLINE | ID: mdl-32857482

ABSTRACT

RATIONALE, AIMS, AND OBJECTIVES: HealthLinks: Chronic Care is a state-wide public hospital initiative designed to improve care for cohorts at-risk of potentially preventable hospitalizations at no extra cost. MonashWatch (MW) is an hospital outreach service designed to optimize admissions in an at-risk cohort. Telehealth operators make regular phone calls (≥weekly) using the Patient Journey Record System (PaJR). PaJR generates flags based on patient self-report, alerting to a risk of admission or emergency department attendance. 'Total flags' of global health represent concerns about self-reported general health, medication, and wellness. 'Red flags' represent significant disease/symptoms concerns, likely to lead to hospitalization. METHODS: A time series analysis of PaJR phone calls to MW patients with ≥1 acute non-surgical admissions in a 20-day time window (10 days pre-admission and 10 days post-discharge) between 23 December 2016 and 11 October 2017. Pettitt's hypothesis-testing homogeneity measure was deployed to analyse Victorian Admitted Episode/Emergency Minimum Datasets and PaJR data. FINDINGS: A MW cohort of 103 patients (mean age 74 ± 15 years; with 59% males) had 263 admissions was identified. Bed days ranged from <1 to 37.3 (mean 5.8 ± 5.8; median 4.1). The MW cohort had 7.6 calls on average in the 20-day pre- and post-hospital period. Most patients reported significantly increased flags 'pre-hospital' admission: medication issues increased on day 7.0 to 8.5; total flags day 3, worse general health days 2.5 to 1.8; and red flags of disease symptoms increased on day 1. These flags persisted following discharge. DISCUSSION/CONCLUSION: This study identified a 'pre-hospital syndrome' similar to a post-hospital phase aka the well-documented 'post-hospital syndrome'. There is evidence of a 10-day 'pre-hospital' window for interventions to possibly prevent or shorten an acute admission in this MW cohort. Further validation in a larger diverse sample is needed.


Subject(s)
Aftercare , Patient Discharge , Emergency Service, Hospital , Female , Hospitalization , Hospitals , Humans , Male , Retrospective Studies , Self Report , Victoria
14.
J Med Internet Res ; 22(12): e18046, 2020 12 01.
Article in English | MEDLINE | ID: mdl-33258781

ABSTRACT

BACKGROUND: MonashWatch is a telehealth public hospital outreach pilot service as a component of the Government of Victoria's statewide redesign initiative called HealthLinks: Chronic Care. Rather than only paying for hospitalizations, projected funding is released earlier to hospitals to allow them to reduce hospitalization costs. MonashWatch introduced a web-based app, Patient Journey Record System, to assess the risk of the journeys of a cohort of patients identified as frequent admitters. Telecare guides call patients using the Patient Journey Record System to flag potential deterioration. Health coaches (nursing and allied health staff) triage risk and adapt care for individuals. OBJECTIVE: The aim was a pragmatic controlled evaluation of the impact of MonashWatch on the primary outcome of bed days for acute nonsurgical admissions in the intention-to-treat group versus the usual care group. The secondary outcome was hospital admission rates. The net promoter score was used to gauge satisfaction. METHODS: Patients were recruited into an intention-to-treat group, which included active telehealth and declined/lost/died groups, versus a systematically sampled (4:1) usual care group. A rolling sample of 250-300 active telehealth patients was maintained from December 23, 2016 to June 23, 2019. The outcome-mean bed days in intervention versus control-was adjusted using analysis of covariance for age, gender, admission type, and effective days active in MonashWatch. Time-series analysis tested for trends in change patterns. RESULTS: MonashWatch recruited 1373 suitable patients who were allocated into the groups: usual care (n=293) and intention-to-treat (n=1080; active telehealth: 471/1080, 43.6%; declined: 485, 44.9%; lost to follow-up: 178 /1080, 10.7%; died: 8/1080, 0.7%). Admission frequency of intention-to-treat compared to that of the usual care group did not significantly improve (P=.05), with a small number of very frequent admitters in the intention-to-treat group. Age, MonashWatch effective days active, and treatment group independently predicted bed days. The analysis of covariance demonstrated a reduction in bed days of 1.14 (P<.001) in the intention-to-treat group compared with that in the usual care group, with 1236 bed days estimated savings. Both groups demonstrated regression-to-the-mean. The downward trend in improved bed days was significantly greater (P<.001) in the intention-to-treat group (Sen slope -406) than in the usual care group (Sen slope -104). The net promoter score was 95% in the active telehealth group compared with typical hospital scores of 77%. CONCLUSIONS: Clinically and statistically meaningful reductions in acute hospital bed days in the intention-to-treat group when compared to that of the usual care group were demonstrated (P<.001), although admission frequency was unchanged with more short stay admissions in the intention-to-treat group. Nonrandomized control selection was a limitation. Nonetheless, MonashWatch was successful in the context of the HealthLinks: Chronic Care capitation initiative and is expanding.


Subject(s)
Hospitalization/statistics & numerical data , Patient Readmission/statistics & numerical data , Telemedicine/methods , Aged , Australia , Female , Humans , Male
16.
Cureus ; 12(5): e8372, 2020 May 31.
Article in English | MEDLINE | ID: mdl-32626616

ABSTRACT

Small intestinal hemangiomas are uncommon tumors that frequently present with gastrointestinal bleeding (GIB). Diagnosis, detection, and treatment can be challenging and may require surgical intervention. An 81-year-old female presented with melena. Video capsule endoscopy revealed active bleeding in the proximal jejunum and push enteroscopy identified a polypoid nodule with central umbilication. The patient underwent laparoscopic resection and jejunal submucosal hemangioma was detected. Submucosal hemangiomas are a rare cause of GIB. As the most common site of submucosal hemangiomas is the mid-jejunum, they are not easy to detect. Surgical intervention is usually required for a definitive diagnosis and definitive treatment.

17.
Curr Gastroenterol Rep ; 22(9): 46, 2020 Jul 11.
Article in English | MEDLINE | ID: mdl-32654103

ABSTRACT

PURPOSE OF REVIEW: The purpose of this review was to examine the historical roots of endoscopic management of ampullary lesions and explore emerging data on improved techniques, technologies, and outcomes. Of specific interest was answering whether there exists a reasonable body of data to support one resection technique or strategy above others. RECENT FINDINGS: Review of recent literature suggests the continued use of endoscopic ampullectomy is a safe and effective means of curative treatment of ampullary adenomas. Complications are relatively infrequent and complete endoscopic resection is possible in a majority of cases, with proper patient and lesion selection. Greater than 2 decades of experience with endoscopic ampullectomy have shown this to be a viable, well-tolerated, and highly effective means of treating ampullary adenomas. While few concrete guidelines exist to advise endoscopists on the ideal technique for resection, experience, patient selection, and prior planning can greatly influence the technical and clinical success of endoscopic ampullectomy.


Subject(s)
Adenocarcinoma/surgery , Adenoma, Bile Duct/surgery , Ampulla of Vater/surgery , Biliary Tract Surgical Procedures/methods , Common Bile Duct Neoplasms/surgery , Adenocarcinoma/diagnosis , Adenocarcinoma/etiology , Adenocarcinoma/pathology , Adenoma, Bile Duct/diagnosis , Adenoma, Bile Duct/etiology , Adenoma, Bile Duct/pathology , Adenomatous Polyposis Coli/complications , Ampulla of Vater/pathology , Biopsy , Common Bile Duct Neoplasms/diagnosis , Common Bile Duct Neoplasms/etiology , Common Bile Duct Neoplasms/pathology , Duodenoscopy , Humans , Practice Guidelines as Topic , Prosthesis Implantation , Stents
18.
Nat Commun ; 11(1): 2829, 2020 Jun 16.
Article in English | MEDLINE | ID: mdl-32546817

ABSTRACT

Saturn's moon Titan has a methane cycle with clouds, rain, rivers, lakes, and seas; it is the only world known to presently have a volatile cycle akin to Earth's tropospheric water cycle. Anomalously specular radar reflections (ASRR) from Titan's tropical region were observed with the Arecibo Observatory (AO) and Green Bank Telescope (GBT) and interpreted as evidence for liquid surfaces. The Cassini spacecraft discovered lakes/seas on Titan, however, it did not observe lakes/seas at the AO/GBT anomalously specular locations. A satisfactory explanation for the ASRR has been elusive for more than a decade. Here we show that the ASRR originate from one terrain unit, likely paleolakes/paleoseas. Titan observations provide ground-truth in the search for oceans on exoearths and an important lesson is that identifying liquid surfaces by specular reflections requires a stringent definition of specular; we propose a definition for this purpose.

19.
Sci Total Environ ; 710: 136273, 2020 Mar 25.
Article in English | MEDLINE | ID: mdl-31918189

ABSTRACT

The preferential elution of ions from melting snowpacks is a complex problem that has been linked to temporary acidification of water bodies. However, the understanding of these processes in snowpacks around the world, including the polar regions that are experiencing unprecedented warming and melting, remains limited despite being instrumental in supporting climate change adaptation. In this study, data collected from a snowmelt lysimeter and snowpits at meadow and forest-gap sites in a high elevation watershed in Colorado were combined with the PULSE multi-phase snowpack chemistry model to investigate the controls of meltwater chemistry and preferential elution. The snowdepth at the meadow site was 64% of that at the forest-gap site, and the snowmelt rate was greater there (meadow snowpit) due to higher solar irradiance. Cations such as Ca2+ and NH4+ were deposited mostly within the upper layers of both the meadow and forest-gap snowpacks, and acid anions such as NO3- and SO42- were more evenly distributed. The snow ion concentrations were generally greater at the forest-gap snowpit, except for NH4+, which indicates that wind erosion of wet and dry deposited ions from the meadow may have reduced concentrations of residual snow. Furthermore, at the forest-gap site, snow interception and scavenging processes such as sublimation, ventilation, and throughfall led to particular ion enrichment of Ca2+, Mg2+, K+, Cl-, SO42- and NO3-. Model simulations and observations highlight that preferential elution is enhanced by low snowmelt rates, with the model indicating that this is due to lower dilution rates and increased contact time and area between the percolating meltwater and the snow. Results suggest that low snowmelt rates can cause multiple early meltwater ionic pulses for ions subject to lower ion exclusion. Ion exclusion rates at the grain-size level have been estimated for the first time.

20.
Foodborne Pathog Dis ; 16(8): 543-549, 2019 08.
Article in English | MEDLINE | ID: mdl-31045445

ABSTRACT

Objectives: To estimate the proportions of human cases of nine specific microbial diseases in New Zealand that were due to transmission by food and the proportion of the foodborne burden that was due to transmission by some specific foods. Materials and Methods: Subjective probability distributions were elicited from 10 food safety experts using a modified Delphi approach. In addition to uniform weighting of experts' opinions, two techniques were used to measure individual's expertise; self-assessment and performance-based weighting using Cooke's classical method. Aggregate estimates were derived by simulation. Results: Food was estimated to be the primary route of transmission for infections due to Campylobacter spp., Listeria monocytogenes, nontyphoid Salmonella spp., Vibrio parahaemolyticus, and Yersinia enterocolitica. Uncertainties were lowest for organisms where the self-assessed expertise level was highest. Conclusions: Foodborne proportion estimates were more "polarized" than for a similar elicitation in 2005. That is, where food was the primary transmission route the estimated proportion on account of food was higher (62.1-90.6% in the current study for self-assessed expertise weighted estimates, compared to 56.2-89.2% in 2005); where food was not the primary transmission route the estimated proportion because of food was lower (27.6-34.0% in the current study compared to 31.5-39.5% in 2005). These estimates represent an essential resource for determining the burden of foodborne disease in New Zealand.


Subject(s)
Food Microbiology , Foodborne Diseases/epidemiology , Foodborne Diseases/microbiology , Foodborne Diseases/prevention & control , Humans , Listeria monocytogenes/isolation & purification , New Zealand/epidemiology , Salmonella/isolation & purification , Vibrio parahaemolyticus/isolation & purification , Yersinia enterocolitica/isolation & purification
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