This manuscript mainly explores the characteristics of turbulence quantities in the wake of tall building clusters of different array size ($N$) and building spacing ($W_S$) arranged in an aligned and regular grid in the flow direction. Velocity fields are measured in a wind tunnel using three-dimensional laser Doppler anemometry. Results show a delayed recovery of $u_{rms}$ and $v_{rms}$ (defined as the root-mean-square of the streamwise and lateral velocities, respectively) in the wake flow compared with the mean flow. Based on the turbulent fluctuations, the extents of the near-, transition- and far-wake regions in Mishra et al. (Boundary-Layer Meteorol., vol. 189, 2023, pp. 1–25) are revisited. In the near wake, we observe a significant reduction in $u_{rms}$ and $v_{rms}$ in the wake of a $4\times 4$ cluster compared with that of a single building. In the transition region, the turbulence intensity magnitudes within the cluster reduce to below their free-stream counterpart; this reduction is associated with the slowly varying nature of the normalised wake deficit in the streamwise direction. The recovery of the root mean square in the far-wake region is observed for $x \geq 2.5W_A$ (where $W_A$ is the width of the cluster), with the mutual interaction of the wakes formed behind the individual buildings reducing with an increase in $W_S$, resulting in a faster recovery of the turbulent fluctuations. Finally, wavelet analysis suggests the existence of multi-scale vortex-shedding frequencies downwind of tall building clusters.

International humanitarian law (IHL) provides the normative foundation for efforts to address the issue of missing persons during and after armed conflict. Whilst IHL does not engage with how parties to an armed conflict may go about restoring peace, there has been speculation that resolving the missing issue, by bringing answers to families about the fate and whereabouts of their missing relatives, can potentially play a role in building peace. This article represents an effort to compile existing evidence in academic and practice literature that supports an understanding of how addressing the missing issue relates to peacebuilding. In so doing, the article seeks to lay out a research agenda to understand how addressing the issue of the missing can serve to advance peacebuilding, and proposes avenues for further research.

In December 2018, an outbreak of Salmonella Enteritidis infections was identified in Canada by whole-genome sequencing (WGS). An investigation was initiated to identify the source of the illnesses, which proved challenging and complex. Microbiological hypothesis generation methods included comparisons of Salmonella isolate sequence data to historical domestic outbreaks and international repositories. Epidemiological hypothesis generation methods included routine case interviews, open-ended centralized re-interviewing, thematic analysis of open-ended interview data, collection of purchase records, a grocery store site visit, analytic comparison to healthy control groups, and case–case analyses. Food safety hypothesis testing methods included food sample collection and analysis, and traceback investigations. Overall, 83 cases were identified across seven provinces, with onset dates from 6 November 2018 to 7 May 2019. Case ages ranged from 1 to 88 years; 60% (50/83) were female; 39% (22/56) were hospitalized; and three deaths were reported. Brand X profiteroles and eclairs imported from Thailand were identified as the source of the outbreak, and eggs from an unregistered facility were hypothesized as the likely cause of contamination. This study aims to describe the outbreak investigation and highlight the multiple hypothesis generation methods that were employed to identify the source.

An investigation into an outbreak of Salmonella Newport infections in Canada was initiated in July 2020. Cases were identified across several provinces through whole-genome sequencing (WGS). Exposure data were gathered through case interviews. Traceback investigations were conducted using receipts, invoices, import documentation, and menus. A total of 515 cases were identified in seven provinces, related by 0–6 whole-genome multi-locus sequence typing (wgMLST) allele differences. The median age of cases was 40 (range 1–100), 54% were female, 19% were hospitalized, and three deaths were reported. Forty-eight location-specific case sub-clusters were identified in restaurants, grocery stores, and congregate living facilities. Of the 414 cases with exposure information available, 71% (295) had reported eating onions the week prior to becoming ill, and 80% of those cases who reported eating onions, reported red onion specifically. The traceback investigation identified red onions from Grower A in California, USA, as the likely source of the outbreak, and the first of many food recall warnings was issued on 30 July 2020. Salmonella was not detected in any tested food or environmental samples. This paper summarizes the collaborative efforts undertaken to investigate and control the largest Salmonella outbreak in Canada in over 20 years.

Settler-colonial futurity and colonial onto-epistemology are embedded across mainstream Australian public education institutions and schooling. While Country is central to Indigenous being, knowledges and pedagogy, Australian public and school education and curricula regularly fail to engage with Country and place in its historical, political, institutional, more-than-human, and relational dimensions. This paper investigates how colonial discourse and narratives permeate public and schooling education resources about mining and the Australian gold rush, including those presented in local Victorian gold rush museums. These support an influential story of Australia’s past/present that erases First Nations1 custodial relations with Country, strengthens settler-colonial futurity and celebrates and legitimises its colonising and extractive relations between people, Country, and ecologies. The paper presents an argument for attending to critical, relational geopolitics in education and environmental education to destabilise and shift these ways of understanding. It considers opportunities and challenges presented by Australian curricula in terms of their capacity to develop geopolitical understandings of past/present/future social and ecological in/justice, and to support new political understandings and sense of connection and belonging with Country.

This article investigates memory practices in connection with retrospective Facebook groups created for remembering specific aspects of the past. It focuses on how members of these groups experience and deal with how Facebook's interface and algorithms enable, shape, and interfere with memory practices. From this point of departure, the article discusses and nuances the idea that a ‘connective turn’ has brought with it an ontological shift in memory culture (Hoskins 2017a) and a ‘greying’ of memories (Hoskins and Halstead 2021). Theoretically, the article draws on Deborah Lupton's (2020) concept of ‘data selves’, which offers an account of how people interact with data and technology. This concept does not view data practices as immaterial but rather as material, corporeal, and affective, thus prompting an understanding of memory practices as hybrid processes where offline and online practices intersect (Gajjala 2019; Merrill forthcoming/2024). In this qualitative study, nine members of retrospective Facebook groups were chosen to participate in semi-structured interviews. The analysis explains the importance of viewing contemporary memory practices as hybrid, showing a greying effect within the affordances of Facebook that shapes both which memories are shared and how memories are shared. In addition, the analysis nuances the idea of an ontological shift in memory culture and the greying of memories by investigating how the interviewees’ deal and struggle with the affordances of the platform in their memory practices.

We present a new explicit formula for the determinant that contains superexponentially fewer terms than the usual Leibniz formula. As an immediate corollary of our formula, we show that the tensor rank of the $n \times n$ determinant tensor is no larger than the $n$-th Bell number, which is much smaller than the previously best-known upper bounds when $n \geq 4$. Over fields of non-zero characteristic we obtain even tighter upper bounds, and we also slightly improve the known lower bounds. In particular, we show that the $4 \times 4$ determinant over ${\mathbb{F}}_2$ has tensor rank exactly equal to $12$. Our results also improve upon the best-known upper bound for the Waring rank of the determinant when $n \geq 17$, and lead to a new family of axis-aligned polytopes that tile ${\mathbb{R}}^n$.

Background: Patients without urinary tract infection (UTI) symptoms but with a positive urine culture are considered to have asymptomatic bacteriuria (ASB). This often represents colonization and treatment is not recommended or clinically beneficial. Treatment of ASB can promote antimicrobial resistance and increased rates of Clostriodies difficile infections. Many cases of ASB are incorrectly assigned as CAUTIs due to over-culturing practices. We hypothesized that a urine culture algorithm, embedded within a best practice alert (BPA) in the electronic medical record (EMR), would reduce urine culturing practices for ASB. Methods: From Feb 2022 through May 2023, a multidisciplinary team implemented an Inpatient Urine Culturing Stewardship Guideline. A BPA fired when a provider placed a urinalysis with reflex to culture (UACC) or urine culture (UC) order for patients who met criteria (Image 1). The BPA directed providers to remove the order, select the appropriate pathway from the guideline, or provide a rationale for placing the order. The intervention was piloted on three intensive care units and two progressive care units, containing both medical and surgical patients. Monthly ordering practices, CAUTI rates, and gram-negative rod (GNR) bacteremia rates from a 13-month pre-intervention baseline period were compared to a 16-month intervention period. Over the same time periods, we also assessed changes in ordering practices for comparison units which did not implement the intervention. Pre-and-post intervention cohorts were analyzed using median two sample tests and Exact Poison Method, as appropriate. Results: On intervention units there was a 41.0% reduction in the median number of UACC and UC orders per 1000 patient days from 16.31 during the baseline period to 9.62 in the intervention period (p=0.0036). Pan cultures per 1000 patient days in which one of the orders was a UACC or UC fell by 42.2% from a median of 10.20 per 1000 patient days to 5.90 (p=0.0008). The comparison units saw no significant reductions in UACC and UC orders (p=0.21) or pan cultures (p=1.0). On the intervention units, the CAUTI rate for the baseline period was 1.31 per 1000 catheter days versus 0.79 in the intervention period (IRR = 1.65; p=0.44). GNR bacteremias remained stable on the intervention units between the baseline and intervention periods (p=0.82). Conclusion: This multidisciplinary intervention, leveraging EMR clinical decision support, reduced urine and pan culturing practices while demonstrating a trend towards a reduced CAUTI rate. The prevalence of GNR bacteremias remained consistent with baseline levels, suggesting the intervention did not cause harm.

Background: Measuring and reporting antibiotic use are essential to antimicrobial stewardship activities. The most common metric to assess facility-level use is days of antibiotic therapy per 1000 days of care (DOT/1000 DOC). This metric may be difficult to calculate, not be readily comparable, or not provide actionable data to individual prescribers, particularly those that work in post-acute and long-term care (PALTC) settings. Here we use data from a centralized dispensing pharmacy to develop antibiotic use metrics suitable for offering individualized feedback to prescribers working in PALTC settings. Methods: We obtained medication dispensing data and resident census data for 13 PALTC settings within the same network. After omitting non-pharmacologic items and limiting the data to medications dispensed from 1/2020 – 12/2022, we determined the following metrics by month: days of antibiotic therapy (DOT), number of medications prescribed, number of antibiotic courses prescribed (antibiotic starts), and the number of individual residents issued a prescription for any medication (unique residents). These metrics were assessed for each facility (2020 – 2022) and for prescribers responsible for > 1% of prescriptions within that facility (2022 only). Prescriber-level unique residents was the number of residents issued a prescription by the given provider. We obtained facility-level census data to calculate antibiotic DOT/1000 resident days of care (DOC) as a standard to which we compared novel metrics. Results: During the 3-year study period, 1718 prescribers at 13 PALTC settings wrote for 672256 medications, including 31087 antibiotic courses. At the facility level, the correlation between monthly antibiotic starts (courses)/unique residents and antibiotic DOT/1000 DOC was 0.83 (p < 0 .0001). The correlation between monthly antibiotic DOT/unique residents and antibiotic DOT/1000 DOC was 0.98 (p < 0 .0001). Trends in monthly values of both novel metrics and DOT/1000 DOC were consistent across the examined period (Figure 1). For individual prescribers, both novel metrics permit assessment and comparison of antibiotic prescription rates over time (Figure 2). Conclusions: Pharmacy dispensing data can be used to determine antibiotic DOT/unique residents and antibiotic starts/unique residents at the facility level and for individual providers. The novel metric antibiotic DOT/unique residents demonstrated strong correlation with antibiotic DOT/1000 DOC at the facility level. In addition to supporting tracking and reporting of antibiotic use among PALTC settings, these new metrics permit visualization of the antibiotic prescribing rates of individuals prescribers, as well as peer comparison, which in turn can lead to actionable feedback that helps improve antibiotic use in the care of PALTC.

Background: Infectious Diseases Society of America guidelines recommend antibiotic prescribing for urinary tract infections (UTIs) when there is a positive culture and signs and symptoms of infection. Despite these guidelines, prescribing for asymptomatic bacteriuria remains prevalent. We conducted a chart review of UTI outpatient encounters to determine the prevalence of antibiotic prescribing as well as patient and provider factors associated with inappropriate prescribing for UTIs. Methods: Patients who were seen at any Department of Veterans Affairs (VA) outpatient clinic with a positive urine culture from 1/1/2019-12/31/2022 were evaluated for inclusion. Exclusion criteria were pregnancy, neutropenia, neurogenic bladder, spinal cord injury/disorder, chronic kidney disease stage III and above, and those undergoing urologic surgical procedures within 7 days. Inappropriate prescribing was defined as an antibiotic prescription given for UTI treatment when no signs or symptoms of infection were recorded during the patient encounter. Chi-square, Fisher’s exact and t-tests were used to evaluate the association between patient and provider characteristics and antibiotic prescribing. Results: Among 341 visits, most patients were male (70%), White (40%), older (mean age of 65.8 ± 15.9 years) and treated at an urban facility (57%). Antibiotics were prescribed for 67% (229/341) of visits. Of the 229 antibiotic courses prescribed, 119 (52%) were appropriate; issued to patients with > = 1 sign or symptom consistent with a urinary tract infection. The most common symptom recorded was dysuria, followed by frequency, urgency, and hematuria (Figure 1). The remaining 110 (48%) antibiotic prescriptions were inappropriate; given to patients without documented UTI-related signs or symptoms. The proportion of inappropriate prescribing was higher among advanced practice practitioners (39/56; 69%) compared to physicians (68/113; 60%; P < 0 .0001). Prescribing of an antibiotic did not differ by gender (p-value=0.3779), race (p-value=0.3972), age (p-value=0.7461) or urban versus rural geography (p-value=0.3647). Discussion: In outpatient clinics, nearly half of antibiotics prescribed to patients with a positive urine culture occurred in the absence of documented of signs or symptoms of a UTI. These results suggest that interventions to improve antibiotic use for UTI-related concerns in the outpatient setting should address UTI-related signs and symptoms as well as asymptomatic bacteriuria. Advanced practice practitioners were more likely to prescribe without documentation of relevant signs or symptoms than physicians. Improving meaningful documentation about the presence or absence of signs and symptoms of a UTI may help reduce inappropriate antibiotic prescriptions in the outpatient setting.

Disclosure: Robin Jump: Research support to my institution from Merck and Pfizer; Advisory boards for Pfizer

Background: Optimizing antimicrobial use (AU) among post-acute and long-term care (PALTC) residents is fundamental to reducing the morbidity and mortality associated with multidrug-resistant organism (MDROs), as well as unintended social consequences related to infection prevention. Data on AU in PALTC settings remains limited. The U.S. Department of Veteran Affairs (VA) provides PALTC to over 23,000 residents at 134 community living centers (CLCs) across the United States annually. Here, we describe AU in VA CLCs, assessing both class and length of therapy. Methods: Monthly AU between January 1, 2015 and December 31, 2019 was extracted from the VA Corporate Data Warehouse across 134 VA CLCs. Antimicrobials and administration routes were based on the National Healthcare Safety Network AU Option protocol for hospitals. Rates of AU were measured as the days of therapy (DOT) per 1,000 resident-days. An antimicrobial course was defined as the same drug and route administered to the same resident with a gap of ≤ three days between administrations. Course duration was measured in days. AU Rates were measured as the days of therapy (DOT) per 1,000 resident-days. Results: The most common class of antimicrobial course administered during the study period was beta-lactam/beta-lactamase inhibitor combinations (15%) followed by fluroquinolones (14%), extended-spectrum cephalosporins (12%) and glycopeptides (11%; Figure 1). Neuraminidase inhibitors had the longest median (IQR) course duration (10 (IQR 8) days), followed by tetracyclines (8 (IQR 8) days), and then folate pathway inhibitors, nitrofurans and 1st/2nd generation cephalosporins (7 (IQR 7) days). Overall, 60% of antimicrobial courses were administered orally, with fluroquinolones the most frequently administered orally (20%). From 2015 – 2019, the annual rate of total antimicrobial use across VA CLCs decreased slightly from 213.6 to 202.5 DOT/1,000 resident-days. During the 5-year study period, fluroquinolone use decreased from 27.47 to 13.36 DOTs/1,000 resident-days. First and 2nd generation cephalosporin use remained relatively stable, but 3rd or greater generation cephalosporin use increased from 14.70 to 19.21 DOTs/1,000 resident-days (Figure 2). Conclusion: The marked decrease in the use of fluoroquinolones at VA CLCs from 2015-2019 is similar to patterns observed for VA hospitals and for non-VA PALTC facilities. The overall use of antibacterial agents at VA CLCs decreased slightly during the study period, but other broad-spectrum agents such as 3rd or greater generation cephalosporins increased over the same period. The strategies used to decrease fluroquinolone use may have application for other antibiotic classes, both in VA and non-VA PALTC settings.

Disclosure: Robin Jump: Research support to my institution from Merck and Pfizer; Advisory boards for Pfizer

Background: In rural areas, antimicrobial stewardship programs often have limited access to infectious disease (ID) expertise. Videoconference Antimicrobial Stewardship Teams (VASTs) pair rural Veterans Affairs (VA) medical centers with an ID expert to discuss treatment of patients with concerns for infection. In a pilot study, VASTs were effective at improving antimicrobial use. Here, we evaluated 12-month operating costs for staffing for 3 VASTs. Methods: We used the following data to describe 12 months of clinical encounters for 3 VASTs operating from January 2022 – March 2023: the number of VAST sessions completed and clinical encounters; Current Procedural Terminology (CPT) codes associated with clinical encounters; session attendees (by role) and the time spent (percent effort) on VAST-related activities. The annual operating cost was based on the annual salaries and percent effort of VAST attendees. We used these characteristics combined with private-sector and Medicare reimbursements to evaluate the cost of implementation and number of clinical encounters needed to offset those costs (breakeven) for each site. Results: Three VASTs recorded 229 clinical encounters during 117 sessions (Table 1). Based on CPT codes, the approximate revenue per patient was $516.46. Site A, the only site to break even, had the most sessions and clinical encounters as well as the lowest operating costs. For Site B, a slight increase in the clinical encounters, which might be achieved by 3 additional VAST sessions, would help achieve breakeven. For Site C, increasing the number of clinical encounters to 3-4 per session would have helped their VAST break even without requiring a decrease in operating costs. Conclusions: The frequency of VAST sessions, volume of clinical encounters, and low operating costs all contributed the VAST at Site A achieving a financial break-even point within 12 months. Consideration of the potential number of clinical encounters and sessions will help other VASTs achieve financial sustainment, independent of cost-savings related to potential decreases in expenditures for antibiotics and antibiotic-related adverse events. These results also provide insight into possible adoption and diffusion of VAST-like programs in the Medicare hospital setting.