Sets on the boundary of a complementary component of a continuum in the plane have been of interest since the early 1920s. Curry and Mayer defined the buried points of a plane continuum to be the points in the continuum which were not on the boundary of any complementary component. Motivated by their investigations of Julia sets, they asked what happens if the set of buried points of a plane continuum is totally disconnected and nonempty. Curry, Mayer, and Tymchatyn showed that in that case the continuum is Suslinian, i.e., it does not contain an uncountable collection of nondegenerate pairwise disjoint subcontinua. In an answer to a question of Curry et al., van Mill and Tuncali constructed a plane continuum whose buried point set was totally disconnected, nonempty, and one-dimensional at each point of a countably infinite set. In this paper, we show that the van Mill–Tuncali example was the best possible in the sense that whenever the buried set is totally disconnected, it is one-dimensional at each of at most countably many points. As a corollary, we find that the buried set cannot be almost zero-dimensional unless it is zero-dimensional. We also construct locally connected van Mill–Tuncali type examples.

He may have died tragically young, but Binyavanga Wainaina’s brilliance lives on. His caustic skewering of white journalism – ‘How to write about Africa’ – was first published in Granta in 2005 (Wainaina 2005). It remains a vital anti-guide to sweeping generalizations and cheap condescension. By comparison, writing about African universities should be easy. After all, aren’t most of us already insiders within, if not institutionalized by, higher education? There lies the rub. Academography, to use Eli Thorkelson’s pithy neologism, is much harder than it looks.

Background: During the COVID-19 pandemic, rates of central line bloodstream infections (CLABSI) increased nationally. Studies pre-pandemic showed improved CLABSI rates with implementation of a standardized vascular access team (VAT).[PL1] [PL2] [mi3] Varying VAT resources and coverage existed in our 10 acute care facilities (ACF) prior to and during the pandemic. VAT scope also varied in 1) process for line selection during initial placement, 2) ability to place a peripherally inserted central catheter (PICC), midline or ultrasound-guided peripheral IV in patients with difficult vascular access, 3) ownership of daily assessment of central line (CL) necessity, and 4) routine CL dressing changes. We aimed to define and implement the ideal VAT structure and evaluate the impact on CLABSI standardized infection ratios (SIR) and rates prior to and during the pandemic. Methods: A multidisciplinary workgroup including representatives from nursing, infection prevention, and vascular access was formed to understand the current state of VAT responsibilities across all ACFs. The group identified key responsibilities a VAT should conduct to aid in CLABSI prevention. Complete VAT coverage[mi4] was defined as the ability to conduct the identified responsibilities daily. We compared the SIR and CLABSI rates between hospitals who had complete VAT (CVAT) coverage to hospitals with incomplete VAT (IVAT) coverage. Given this work occurred during the pandemic, we further stratified our analysis based on a time frame prior to the pandemic (1/2015 – 12/2019) and intra-pandemic (1/2020 - 12/2022). Results: The multidisciplinary team identified 6 key components of complete VAT coverage: Assessment for appropriate line selection prior to insertion, ability to insert PICC and midlines, daily CL and midline care and maintenance assessments, daily assessment of necessity for CL, and weekly dressing changes for CL and midlines[NA5] . A cross walk of VAT scope (Figure 1) was performed in October 2022 which revealed two facilities (A and E) which met CVAT criteria. Pre-pandemic, while IVAT CLABSI rates and SIR were higher than in CVAT units, the difference was not statistically significant. During the pandemic, however, CLABSI rates and SIR were 40-50% higher in IVAT compared to CVAT facilities (Incident Rate Ratio 1.5, 95% CI 1.1-2.0 and SIR Relative Ratio 1.4, 95% CI1.1-1.9 respectively) (Table 1). Conclusions: CLABSI rates were lower in facilities with complete VAT coverage prior to and during the COVID-19 pandemic suggesting a highly functioning VAT can aid in preventing CLABSIs, especially when a healthcare system is stressed and resources are limited.

The Arabian leopard Panthera pardus nimr is categorized as Critically Endangered, with < 200 individuals estimated to remain in the wild. Historically the species ranged over an extensive area of western Saudi Arabia but, with no confirmed sightings since 2014, investigating potential continued presence and distribution is of critical conservation importance. We present the results of a comprehensive survey designed to detect any remaining Arabian leopard populations in Saudi Arabia. We conducted 14 surveys, deploying 586 camera-trap stations at 13 sites, totalling 82,075 trap-nights. Questionnaire surveys were conducted with 843 members of local communities across the Arabian leopard's historical range to assess the presence of leopards, other predators and prey species. Predator scats were collected ad hoc by field teams and we used mitochondrial DNA analysis to identify the originating species. We obtained 62,948 independent photographs of animals and people, but none were of Arabian leopards. Other carnivores appeared widespread and domestic animals were numerous, but wild prey were comparatively scarce. Three questionnaire respondents reported sightings of leopards within the previous year, but targeted camera-trap surveys in these areas did not yield evidence of leopards. Of the 143 scats sent for analysis, no DNA was conclusively identified as that of the leopard. From this extensive study, we conclude there are probably no surviving, sustainable populations of Arabian leopards in Saudi Arabia. Individual leopards might be present but were not confirmed. Any future Arabian leopard conservation in Saudi Arabia will probably require reintroduction of captive-bred leopards.

Why are Nigeria’s universities launching a growing number of open access journals while simultaneously expecting their academic staff to publish ‘internationally’? And what impact do these expectations have on Nigerian journals? Drawing on interviews with editors and publishers, we describe the emergence of a hyperlocal ‘credibility economy’ within the Nigerian academy. The great majority of Nigerian scholarly journals are excluded from Scopus and Web of Science, the two main global citation indexes. Stigmatized by geography, Nigerian journals are ignored, rendered invisible, classed as poor quality or condemned as ‘predatory’. Historicizing these trends, we illustrate our argument with four case studies: two science and technology journals hosted by universities and two independent publishers, one with expertise in African studies, the other in information studies. In each case, we explore the motivations, commitments and strategies of editors and publishers. Their stories exemplify the impact of colonial histories, global discourses and bibliometric infrastructures on African research publishing cultures. The histories, logics and fragilities of this regional research ecosystem reveal how Africa’s scholars and publishers are getting by – but only just – amid the metricized judgements of the global research economy.

A chloroacetamide herbicide by application timing factorial experiment was conducted in 2017 and 2018 in Mississippi to investigate chloroacetamide use in a dicamba-based Palmer amaranth management program in cotton production. Herbicides used were S-metolachlor or acetochlor, and application timings were preemergence, preemergence followed by (fb) early postemergence, preemergence fb late postemergence, early postemergence alone, late postemergence alone, and early postemergence fb late postemergence. Dicamba was included in all preemergence applications, and dicamba plus glyphosate was included with all postemergence applications. Differences in cotton and weed response due to chloroacetamide type were minimal, and cotton injury at 14 d after late postemergence application was less than 10% for all application timings. Late-season weed control was reduced up to 30% and 53% if chloroacetamide application occurred preemergence or late postemergence only, respectively. Late-season weed densities were minimized if multiple applications were used instead of a single application. Cotton height was reduced by up to 23% if a single application was made late postemergence relative to other application timings. Chloroacetamide application at any timing except preemergence alone minimized late-season weed biomass. Yield was maximized by any treatment involving multiple applications or early postemergence alone, whereas applications preemergence or late postemergence alone resulted in up to 56% and 27% yield losses, respectively. While no yield loss was reported by delaying the first of sequential applications until early postemergence, forgoing a preemergence application is not advisable given the multiple factors that may delay timely postemergence applications such as inclement weather.

Microstructures, including crystallographic fabric, within the margin of streaming ice can exert strong control on flow dynamics. To characterize a natural setting, we retrieved three cores, two of which reached bed, from the flank of Jarvis Glacier, eastern Alaska Range, Alaska. The core sites lie ~1 km downstream of the source, with abundant water present in the extracted cores and at the base of the glacier. All cores exhibit dipping layers, a combination of debris bands and bubble-free domains. Grain sizes coarsen on average approaching the lateral margin. Crystallographic orientations are more clustered and with c-axes closer to horizontal nearer the lateral margin. The measured fabric is sufficiently weak to induce little mechanical anisotropy, but the data suggest that despite the challenging conditions of warm ice, abundant water and a short flow distance, many aspects of the microstructure, including measurable crystallographic fabric, evolved in systematic ways.

Wind-driven snow redistribution can increase the spatial heterogeneity of snow accumulation on ice caps and ice sheets, and may prove crucial for the initiation and survival of glaciers in areas of marginal glaciation. We present a snowdrift model (Snow_Blow), which extends and improves the model of Purves, Mackaness and Sugden (1999, Journal of Quaternary Science 14, 313–321). The model calculates spatial variations in relative snow accumulation that result from variations in topography, using a digital elevation model (DEM) and wind direction as inputs. Improvements include snow redistribution using a flux routing algorithm, DEM resolution independence and the addition of a slope curvature component. This paper tests Snow_Blow in Antarctica (a modern environment) and reveals its potential for application in palaeoenvironmental settings, where input meteorological data are unavailable and difficult to estimate. Specifically, Snow_Blow is applied to the Ellsworth Mountains in West Antarctica where ablation is considered to be predominantly related to wind erosion processes. We find that Snow_Blow is able to replicate well the existing distribution of accumulating snow and snow erosion as recorded in and around Blue Ice Areas. Lastly, a variety of model parameters are tested, including depositional distance and erosion vs wind speed, to provide the most likely input parameters for palaeoenvironmental reconstructions.