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A 350 14C yr discrepancy between bone and tooth dates from the same grave at the Early Neolithic cemetery of Shamanka II, Lake Baikal, southern Siberia: reservoir effects or a misplaced mandible?
(Radiocarbon, 2025-01) Schulting, Rick; Scharlotta, Ian; Lieverse, Angela; Jessup, Erin; Bronk Ramsey, Christopher; Bazaliiskii, Vladimir I; Weber, Andrzej
A 350 14C yr discrepancy was found between dates on postcranial remains and mandibular teeth on what was thought to be the same individual from the Early Neolithic cemetery of Shamanka II, Lake Baikal. Stable nitrogen isotope results suggested a major shift in diet between childhood (when the teeth formed) and adulthood (represented by the postcrania), which could have resulted in different 14C ages through a freshwater reservoir effect. Subsequent additional dating on the mandible and postcranial elements, however, indicated that the mandible actually belonged to a different individual. More subtle reservoir effects can be seen on the sequentially forming teeth and mandible. The practice by prehistoric hunter-gatherers of Lake Baikal of re-opening graves and removing cranial elements has long been known, but this is the first evidence for the inclusion of a mandible from a separate individual, though whether it was intentional or incidental is uncertain. As well as providing new insights into mid-Holocene mortuary practices in the region, our findings raise a cautionary note for the examination of disturbed graves.
A case study of the patient wait experience in an emergency department with therapy dogs
(Patient Experience Journal, 2019) Dell, Colleen; Stempien, James; Broberg, Lindsey; Husband, Alicia; Jurke, Lacey
The quality of patient healthcare is a growing concern in Canada’s hospital emergency departments (ED) due to increasing wait times and associated adverse outcomes. A developing body of literature indicates that therapy dogs can positively impact the patient experience. In 2016, members of our team partnered with the Royal University Hospital (RUH) in Saskatchewan to become the first ED in Canada to integrate a visiting therapy dog to positively impact the patient wait experience. The aim of this preliminary case study was to examine if and how this unique initiative impacted patients’ feelings during their ED wait. A brief questionnaire was completed with one-hundred and twenty-four patients pre and post-therapy dog visit and a research observer documented the encounters. Quantitative and qualitative analysis of the data revealed that visiting with a therapy dog in the ED appeared to improve patients’ feelings. Specifically, patients’ perceived comfort levels increased and their distress levels decreased, and the encounters were considered by patients to be a welcome distraction from the stressful ED environment. Our team, comprised of clinicians, researchers, therapy dog handlers and patient advocates documented the advantages and challenges of implementing the initiative. The outcomes support further study of patients’ wait time experiences in the ED and the utility of a visiting therapy dog.
A comparative study of the long-term aqueous durability of brannerite (Ce0.94Ti2O6–δ) and glass-brannerite (Fe-Al-BG-Ce0.94Ti2O6–δ) composite materials
(Applied Surface Science, 2025-01) Mikhchian, Mehrnaz; Grosvenor, Andrew
The long-term aqueous corrosion behavior of Fe-Al borosilicate glass-brannerite (Fe-Al-BG- Ce0.94Ti2O6–δ) composite material as a potential nuclear wasteform has been investigated to understand how the corrosion behavior of these materials can be compared to current nuclear wasteforms (i.e., borosilicate glass). It was found that the aqueous corrosion behavior of the Fe-Al-BG-Ce0.94Ti2O6–δ composite material resulted from a combined corrosion behavior of the individual Fe-Al-BG and Ce0.94Ti2O6–δ phases when these materials were exposed to deionized water. A combination of surface and bulk analyses has demonstrated that the surface composition and chemistry of Ce0.94Ti2O6–δ and Fe-Al-BG-Ce0.94Ti2O6–δ composite materials were affected by aqueous corrosion, whereas the long-range (i.e., bulk) structure of these materials remained stable over 365 days of exposure to deionized water. This study has shown that the corrosion resistance of Fe-Al-BG-Ce0.94Ti2O6–δ composite material is comparable to Fe-Al-BG, which suggests that this composite material could be further investigated as a potential substitute for borosilicate glass nuclear wasteforms.
A comparison of seasonal flexibility in pectoralis muscle fiber type and enzyme activity in migratory and resident sparrow species
(Journal of Experimental Biology, 2024-02) Lewicki, Louisa M.; Zhang, Marina; Staples, James; Guglielmo, Christopher G.; Ivy, Catherine
The pectoralis muscle in birds is important for flight and thermogenesis. In migratory songbirds this muscle exhibits seasonal flexibility in size, but whether this flexibility reflects changes in muscle fiber type has not been well documented. We investigated how seasonal changes in photoperiod affected pectoralis muscle fiber type and metabolic enzymes, comparing among three closely related sparrow species: two seasonal migrants and one year-round, temperate climate resident. We quantified fast oxidative glycolytic (FOG) and fast glycolytic (FG) fibers histologically, and measured activities of citrate synthase (CS) and lactate dehydrogenase (LDH) in the pectoralis muscle of the three species that were acclimated to long or short periods of daylight. In all species, FOG was the predominant fiber type, but song sparrows had FG fibers regardless of daylight conditions. By contrast, Lincoln's sparrows incorporated FG fibers only under short-daylight conditions, and house sparrows did not significantly express FG fibers, regardless of daylight length. Both migratory species increased LDH activity in short-daylight conditions but did not alter CS activity. In contrast, resident house sparrows did not alter CS or LDH activity with changes in daylight length. Our findings suggest that the presence of FG fibers is important for seasonal flexibility in LDH activity. Additionally, migratory species exhibited seasonal flexibility in muscle fiber type and enzyme activity, presumably to support migratory flight, while the resident species did not exhibit such seasonal flexibility, suggesting that this consistent phenotype is important year-round, despite changing thermogenic requirements.
A Highly Sensitive Chitosan-Based SERS Sensor for the Trace Detection of a Model Cationic Dye
(MDPI, 2024-08-28) Vafakish, Bahareh; Wilson, Lee
The rapid detection of contaminants in water resources is vital for safeguarding the environment, where the use of eco-friendly materials for water monitoring technologies has become increasingly prioritized. In this context, the role of biocomposites in the development of a SERS sensor is reported in this study. Grafted chitosan was employed as a matrix support for Ag nanoparticles (NPs) for the surface-enhanced Raman spectroscopy (SERS). Chitosan (CS) was decorated with thiol and carboxylic acid groups by incorporating S-acetyl mercaptosuccinic anhydride (SAMSA) to yield CS-SAMSA. Then, Ag NPs were immobilized onto the CS-SAMSA (Ag@CS-SAMSA) and characterized by spectral methods (IR, Raman, NIR, solid state 13C NMR with CP-MAS, XPS, and TEM). Ag@CS-SAMSA was evaluated as a substrate for SERS, where methylene blue (MB) was used as a model dye adsorbate. The Ag@CS-SAMSA sensor demonstrated a high sensitivity (with an enhancement factor ca. 108) and reusability over three cycles, with acceptable reproducibility and storage stability. The Raman imaging revealed a large SERS effect, whereas the MB detection varied from 1–100 μM. The limits of detection (LOD) and quantitation (LOQ) of the biocomposite sensor were characterized, revealing properties that rival current state-of-the-art systems. The dye adsorption profiles were studied via SERS by fitting the isotherm results with the Hill model to yield the ΔG°ads for the adsorption process. This research demonstrates a sustainable dual-function biocomposite with tailored adsorption and sensing properties suitable for potential utility in advanced water treatment technology and environmental monitoring applications.
A New Argument for Ethical Evidentialism
(Springer, 2024-08-09) Zamulinski, Brian
This paper contains a new argument for evidentialism as an ethical rather than an epistemic doctrine. The argument relies on new developments in consequentialist thinking. The insights of the proponents of the moral encroachment thesis are used to show that we need higher standards of evidence, and to develop the concept of ethically sufficient evidence. It is demonstrated that prospectivism (subjective consequentialism) supports the contentions that we should not believe without ethically sufficient evidence, that we are permitted to believe when we have it, and that we are obligated to investigate to acquire it. It is argued that we do not have any obligations to believe. The ethical evidentialism argued for here is distinguishable from Clifford’s ethics of belief. Developing the doctrine clarifies some of our moral obligations, makes a positive contribution to prospectivism, and shows that evidentialism is better construed as an ethical doctrine.
A new highly stable multifunctional two-dimensional Si2BN monolayer quantum material with a direct bandgap predicted by density functional theory
(Royal Society of Chemistry [Society Publisher], 2024-07) Djamel, Bezzerga; Chelil, Naouel; Mohammed, Sahnoun; Gusarov, Sergey; Chang, Gap Soo; Naseri, Mosayeb
In this work, we present a novel two-dimensional (2D) Si2BN structure (2D δ-Si2BN) predicted using density functional theory (DFT). The proposed structure exhibits a unique double quasi-planar layer interconnected by covalent bonds, demonstrating lower energy compared to the previously reported planar Si2BN nanosheet. Our calculations, conducted at the HSE06 level of theory, reveal its semiconductor nature with a direct band gap of 1.24 eV at the gamma point. The 2D material exhibits exceptional light absorption in the visible region, prompting an exploration of its potential in photovoltaic applications. Remarkably, our findings indicate a maximum theoretical efficiency of 27.6%, underscoring its promise for renewable energy technologies. Furthermore, employing modern polarization theory, we unveil the ferroelectric properties of the Si2BN monolayer. Notably, a large out-of-plane polarization is observed. It was found that the unstrained 2D δ-Si2BN monolayer demonstrates an impressive out-of-plane spontaneous electric polarization of 28.98 × 10−10 C m−1, a value six times greater than previously referenced Janus materials. This remarkable enhancement in ferroelectric capabilities positions the Si2BN monolayer as a promising candidate for applications in next generation novel information storage, nano-electronic, and optoelectronic devices. These findings not only contribute to the understanding of the structural and electronic properties of the 2D δ-Si2BN monolayer but also highlight its potential for various technological applications, marking a significant advancement in the field of nanomaterials.
Accurate and Efficient Numerical Simulation of Land Models Using SUMMA With SUNDIALS
(Wiley, 2024-11-27) Spiteri, Raymond John; Van Beusekom, Ashley; Klenk, Kyle; Zolfaghari, Reza; Trim, Sean; Knoben, Wouter; Ireson, Andrew; Clark, Martyn
Numerical simulation of land models without error control can be highly inaccurate. We present the incorporation of the Suite of Nonlinear and Differential-Algebraic Equation Solvers (SUNDIALS) package to solve the equations that simulate thermodynamics and hydrologic processes in the Structure for Unifying Multiple Modeling Alternatives (SUMMA) land model. The algorithmic features of SUNDIALS, such as error estimation and adaptive order and step-size control, result in a SUMMA-SUNDIALS model that delivers substantially improved accuracy and relative computational efficiency compared to integration with the previous SUMMA model, which uses the low-order backward Euler method with no rigorous error control. The results are demonstrated through simulations over the North American continent with more than 500,000 spatial elements. Compared to the previous SUMMA model, we find that the simulations produced by the SUMMA-SUNDIALS model are orders of magnitude closer to converged solutions for the same computational cost. Being able to efficiently perform more reliable simulations makes the SUMMA-SUNDIALS model a powerful tool for improving our understanding of the terrestrial component of the Earth System.
Acidic microenvironments in waste rock characterized by neutral drainage: Bacteria-mineral interactions at sulfide surfaces
(MDPI, 2014-03-21) Dockrey, John W.; Lindsay, Matthew B. J.; Mayer, K. Ulrich; Beckie, Roger D.; Norlund, Kelsey L. I.; Warren, Lesley; Southam, Gordon
Microbial populations and microbe-mineral interactions were examined in waste rock characterized by neutral rock drainage (NRD). Samples of three primary sulfide-bearing waste rock types (i.e., marble-hornfels, intrusive, exoskarn) were collected from field-scale experiments at the Antamina Cu–Zn–Mo mine, Peru. Microbial communities within all samples were dominated by neutrophilic thiosulfate oxidizing bacteria. However, acidophilic iron and sulfur oxidizers were present within intrusive waste rock characterized by bulk circumneutral pH drainage. The extensive development of microbially colonized porous Fe(III) (oxy)hydroxide and Fe(III) (oxy)hydroxysulfate precipitates was observed at sulfide-mineral surfaces during examination by field emission-scanning electron microscopy-energy dispersive X-ray spectroscopy (FE-SEM-EDS). Linear combination fitting of bulk extended X-ray absorption fine structure (EXAFS) spectra for these precipitates indicated they were composed of schwertmannite [Fe8O8(OH)6–4.5(SO4)1–1.75], lepidocrocite [γ-FeO(OH)] and K-jarosite [KFe3(OH)6(SO4)2]. The presence of schwertmannite and K-jarosite is indicative of the development of localized acidic microenvironments at sulfide-mineral surfaces. Extensive bacterial colonization of this porous layer and pitting of underlying sulfide-mineral surfaces suggests that acidic microenvironments can play an important role in sulfide-mineral oxidation under bulk circumneutral pH conditions. These findings have important implications for water quality management in NRD settings.
Activity in the pontine reticular nuclei scales with handgrip force in humans
(American Physiological Society, 2024-04-23) Danielson, Tyler L.; Gould, Layla A.; DeFreitas, Jason; MacLennan, Rob; Ekstrand, Chelsea; Borowsky, Ron; Farthing, Jonathan P.; Andrushko, Justin W.
The neural pathways that contribute to force production in humans are currently poorly understood, as the relative roles of the corticospinal tract and brainstem pathways, such as the reticulospinal tract (RST), vary substantially across species. Using functional magnetic resonance imaging (fMRI), we aimed to measure activation in the pontine reticular nuclei (PRN) during different submaximal handgrip contractions to determine the potential role of the PRN in force modulation. Thirteen neurologically intact participants (age: 28 ± 6 yr) performed unilateral handgrip contractions at 25%, 50%, 75% of maximum voluntary contraction during brain scans. We quantified the magnitude of PRN activation from the contralateral and ipsilateral sides during each of the three contraction intensities. A repeated-measures ANOVA demonstrated a significant main effect of force (P = 0.012, η2p = 0.307) for PRN activation, independent of side (i.e., activation increased with force for both contralateral and ipsilateral nuclei). Further analyses of these data involved calculating the linear slope between the magnitude of activation and handgrip force for each region of interest (ROI) at the individual-level. One-sample t tests on the slopes revealed significant group-level scaling for the PRN bilaterally, but only the ipsilateral PRN remained significant after correcting for multiple comparisons. We show evidence of task-dependent activation in the PRN that was positively related to handgrip force. These data build on a growing body of literature that highlights the RST as a functionally relevant motor pathway for force modulation in humans. NEW & NOTEWORTHY In this study, we used a task-based functional magnetic resonance imaging (fMRI) paradigm to show that activity in the pontine reticular nuclei scales linearly with increasing force during a handgrip task. These findings directly support recently proposed hypotheses that the reticulospinal tract may play an important role in modulating force production in humans.
Adapting to Climate Change Through Source Water Protection: Case Studies from Alberta and Saskatchewan, Canada
(Scholarship@Western, 2018) Patrick, Robert J.
The protection of drinking water sources continues to gain momentum in First Nation communities on the Canadian Prairie. Through the identification of potential threats to drinking water sources communities are taking action to mitigate those threats. This article explores the extent to which climate change has been taken into consideration in recent source water protection planning community exercises. In addition, this article describes how source water protection planning has potential to enhance community adaptation strategies to reduce the impacts of climate change on source water and drinking water systems. Results are based on six case studies from Alberta and Saskatchewan.
Adsorption of (Poly)vanadate onto Ferrihydrite and Hematite: An In Situ ATR–FTIR Study
(American Chemical Society (ACS) Publications, 2020-03-25) Vessey, Colton; Schmidt, Michael P.; Abdolahnezhad, Mojtaba; Peak, Derek; Lindsay, Matthew B. J.
Vanadium (V) has been a useful trace metal in describing Earth’s biogeochemical cycling and development of industrial processes; however, V has recently been recognized as a potential contaminant of concern. Although Fe (oxyhydr)oxides are important sinks for aqueous V in soils and sediments, our understanding of adsorption mechanisms is currently limited to mononuclear species (i.e., HxVO4(3–x)–). Here we use in situ attenuated total reflectance – Fourier transform infrared spectroscopy to examine sorption mechanisms and capacity for (poly)vanadate attenuation by ferrihydrite and hematite from pH 3 to 6. Adsorption isotherms illustrate the low affinity of polyvanadate species for ferrihydrite surfaces compared to hematite. Mononuclear V species (i.e., [HxVO4](3−x)− and VO2+) were present at all experimental conditions. At low surface loadings and pH 5 and 6, H2VO4− adsorption onto ferrihydrite and hematite surfaces results from formation of inner sphere complexes. At [V]T above 250 µM, adsorbed polynuclear V species in this study include H2V2O72− and V4O124−. Whereas, HV10O286−, H3V10O285−, and NaHV10O284− are the predominant adsorbed species at pH 3 and 4 and elevated [V]T. Surface polymers were identified on hematite at all experimental pH values, whereas polymeric adsorption onto ferrihydrite was limited to pH 3 and 4. These results suggest that hematite offers a more suitable substrate for polymer complexation compared to ferrihydrite. Our results demonstrate the pH and concentration dependant removal of (poly)vanadate species by Fe(III) (oxyhydr)oxides, which has implications for understanding V mobility, behaviour, and fate in the environment.
Advances in mapping sub-canopy snow depth with unmanned aerial vehicles using structure from motion and lidar techniques
(Copernicus Publications on behalf of the European Geosciences Union, 2019) Harder, Phillip; Pomeroy, John; Helgason, Warren D.
Vegetation has a tremendous influence on snow processes and snowpack dynamics yet remote sensing techniques to resolve the spatial variability of sub-canopy snow depth are lacking. Unmanned Aerial Vehicles (UAV) have had recent widespread application to capture high resolution information on snow processes and are herein applied to the sub-canopy snow depth challenge. Previous demonstrations of snow depth mapping with UAV Structure from Motion (SfM) and airborne lidar have focussed on non-vegetated surfaces or reported large errors in the presence of vegetation. In contrast, UAV-lidar systems have high-density point clouds, measure returns from a wide range of scan angles, and so have a greater likelihood of successfully sensing the sub-canopy snow depth. The effectiveness of UAV-lidar and UAV-SfM in mapping snow depth in both open and forested terrain was tested in a 2019 field campaign in the Canadian Rockies Hydrological Observatory, Alberta and at Canadian Prairie sites near Saskatoon, Saskatchewan, Canada. Only UAV-lidar could successfully measure the sub-canopy snow surface with reliable sub-canopy point coverage, and consistent error metrics (RMSE <0.17m and bias -0.03m to -0.13m). Relative to UAV-lidar, UAV-SfM did not consistently sense the sub-canopy snow surface, the interpolation needed to account for point cloud gaps introduced interpolation artefacts, and error metrics demonstrate relatively large variability (RMSE <0.33m and bias 0.08 m to -0.14m). With the demonstration of sub-canopy snow depth mapping capabilities a number of early applications are presented to showcase the ability of UAV-lidar to effectively quantify the many multiscale snow processes defining snowpack dynamics in mountain and prairie environments.
All 81 crepant resolutions of a finite quotient singularity are hyperpolygon spaces
(AMS: Journal of Algebraic Geometry, 2024) Bellamy, Gwyn; Craw, Alastair; Rayan, Steven; Schedler, Travis; Weiß, Hartmut
Aloe vera mucilage as a sustainable biopolymer flocculant for efficient arsenate anion removal from water
(The Royal Society of Chemistry, 2024-07-24) Venegas-García, Deysi J.; Wilson, Lee; De la Cruz Guzmán , Paola Mayela
In recent years, utilization of biopolymers as natural coagulant–flocculant (CF) systems has become an area of interest, due to their sustainable nature (renewable, biodegradable, and non-toxic) and potential utility as alternative systems to replace synthetic flocculants. Herein, a biopolymer extracted from Aloe vera mucilage (AVM) was investigated for its arsenic(V) removal properties in a CF water treatment process. Structural characterization of AVM was supported by spectroscopy (FTIR, 13C solids NMR & XPS), TGA, rheology, and pHpzc. The arsenic(V) removal process was optimized by employing the Box–Behnken design under three main factors (coagulant, flocculant dosage and initial arsenic(V) concentration), which led to a reduction of the initial arsenic(V) concentration to levels below the Maximum Acceptable Concentration (MAC; 10 μg L−1). The kinetics and thermodynamics of arsenic(V) removal were analyzed with a one-pot in situ method, where the kinetic profiles followed a pseudo-first-order model. The thermodynamic parameters are characteristic of a spontaneous (entropy-driven) and endothermic physisorption removal process. Flocs isolated from the process were analyzed by XPS, where the results reveal that calcium and amide groups of AVM contribute to the arsenic(V) removal mechanism.
Alum addition triggers hypoxia in an engineered pit lake
(MDPI, 2022-02-26) Jessen, Gerdhard L.; Chen, Lin-Xing; Mori, Jiro F.; Colenbrander Nelson, Tara E.; Slater, Gregory F.; Lindsay, Matthew B. J.; Banfield, Jillian F.; Warren, Lesley A.
Here, we examine the geobiological response to a whole-lake alum (aluminum sulfate) treatment (2016) of Base Mine Lake (BML), the first pilot-scale pit lake established in the Alberta oil sands region. The rationale for trialing this management amendment was based on its successful use to reduce internal phosphorus loading to eutrophying lakes. Modest increases in water cap epilimnetic oxygen concentrations, associated with increased Secchi depths and chlorophyll-a concentrations, were co-incident with anoxic waters immediately above the fluid fine tailings (FFT) layer post alum. Decreased water cap nitrate and detectable sulfide concentrations, as well as increased hypolimnetic phospholipid fatty acid abundances, signaled greater anaerobic heterotrophic activity. Shifts in microbial community to groups associated with greater organic carbon degradation (i.e., SAR11-LD12 subclade) and the SRB group Desulfuromonodales emerged post alum and the loss of specialist groups associated with carbon-limited, ammonia-rich restricted niches (i.e., MBAE14) also occurred. Alum treatment resulted in additional oxygen consumption associated with increased autochthonous carbon production, watercap anoxia and sulfide generation, which further exacerbate oxygen consumption associated with on-going FFT mobilized reductants. The results illustrate the importance of understanding the broader biogeochemical implications of adaptive management interventions to avoid unanticipated outcomes that pose greater risks and improve tailings reclamation for oil sands operations and, more broadly, the global mining sector.
An anomalous shallow-marine ichnofacies gradient from the Lower Devonian Talacasto Formation of the Argentine Precordillera
(Palaeogeography, Palaeoclimatology, Palaeoecology, 2025-01) Wenger, Federico D.; Buatois, Luis A.; Mángano, M. Gabriela; Muñoz, Diego F.; Rustán, Juan J.
The Lower Devonian Talacasto Formation in western Argentina records deposition in wave-dominated shallow-marine environments. This unit comprises a large-scale progradational succession, transitioning from black, parallel-laminated mudstone in the lower interval to siltstone and very fine- to medium-grained sandstone in the upper interval. The succession spans environments ranging from the shelf to the upper shoreface. Three trace-fossil assemblages have been identified: (1) Palaeophycus assemblage, including Palaeophycus heberti, P. tubularis, and Helminthopsis isp., corresponding to the shelf; (2) Phycosiphon-Zoophycos assemblage with Zoophycos isp., Phycosiphon incertum, Nereites missouriensis, and Chondrites isp., ranging from the lower offshore to the lower/middle shoreface; and (3) Rosselia assemblage containing Rosselia socialis, Skolithos isp., Arenicolites isp., Palaeophycus tubularis, and escape trace fossils, corresponding to the offshore transition and the lower/middle shoreface. Two ichnofacies have been identified: distal Cruziana and Skolithos Ichnofacies. Unlike the traditional ichnofacies model, the Talacasto Formation shows an onshore expansion of the distal Cruziana Ichnofacies, which is present not only in the lower offshore, but in the upper offshore, offshore transition, and lower shoreface as well. In contrast, the archetypal Cruziana Ichnofacies is not present. This anomalous distribution is attributed to an interplay of ecologic and taphonomic factors combined with the restricted topography of the southern portion of the Precordillera Basin. Low-energy conditions and high food supply for prolonged times allowed for the obliteration of shallow-tier trace fossils by deeper and widely distributed burrows, favoring the onshore expansion of the distal Cruziana Ichnofacies and preventing the preservation of the typical elements of the archetypal Cruziana Ichnofacies. Areas subjected to greater storm influence provided favorable conditions for the development of the Skolithos Ichnofacies.
An ecological quantification of the relationships between water, sanitation and infant, child, and maternal mortality
(Environmental Health, 2012) Cheng, June J.; Schuster Wallace, Corinne; Watt, Susan; Newbold, Bruce; Mente, Andrew
Background: Water and sanitation access are known to be related to newborn, child, and maternal health. Our study attempts to quantify these relationships globally using country-level data: How much does improving access to water and sanitation influence infant, child, and maternal mortality? Methods: Data for 193 countries were abstracted from global databases (World Bank, WHO, and UNICEF). Linear regression was used for the outcomes of under-five mortality rate and infant mortality rate (IMR). These results are presented as events per 1000 live births. Ordinal logistic regression was used to compute odds ratios for the outcome of maternal mortality ratio (MMR). Results: Under-five mortality rate decreased by 1.17 (95%CI 1.08-1.26) deaths per 1000,p< 0.001, for every quartile increase in population water access after adjustments for confounders. There was a similar relationship between quartile increase of sanitation access and under-five mortality rate, with a decrease of 1.66 (95%CI 1.11-1.32) deaths per 1000,p<0.001. Improved water access was also related to IMR, with the IMR decreasing by 1.14 (95%CI 1.05-1.23) deaths per 1000,p< 0.001, with increasing quartile of access to improved water source. The significance of this relationship was retained with quartile improvement in sanitation access, where the decrease in IMR was 1.66 (95%CI 1.11-1.32) deaths per 1000,p< 0.001. The estimated odds ratio that increased quartile of water access was significantly associated with increased quartile of MMR was 0.58 (95%CI 0.39-0.86),p= 0.008. The corresponding odds ratio for sanitation was 0.52 (95%CI 0.32-0.85),p= 0.009, both suggesting that better water and sanitation were associated with decreased MMR. Conclusions: Our analyses suggest that access to water and sanitation independently contribute to child and maternal mortality outcomes. If the world is to seriously address the Millennium Development Goals of reducing child and maternal mortality, then improved water and sanitation accesses are key strategies.
Analytical formulas for geometrical factor and sensitivity for long electrodes
(Wiley, 2024-11-22) Butler, S.L.
In the electrical resistivity method, electrodes are usually modelled as point current sources and point voltage measurements. If the burial depth of the electrode is significant compared with the spacing between electrodes, this point approximation may not be accurate. Common situations employing long electrodes include the use of metal-cased boreholes as electrodes and small-scale, high-resolution environmental, engineering and archaeological surveys where electrode spacings may be very small. In this contribution, I present analytical expressions for the mutual resistance between long electrodes modelled as line current sources. Mutual resistances are then used to calculate geometrical factors. Additionally, I present an expression for the current density and use it to derive an analytical expression for the sensitivity of electrode arrays with long electrodes. The sensitivity is, in turn, used to calculate the mean depth and position which can be used as estimates of depth and position of investigation and as pseudosection plot points. Example calculations using the geometrical factor, sensitivity and mean depth are shown, and comparisons are made with simulations and lab-scale experiments.
An approach to complex texts in multiple documents
(Digital Studies in the Humanities, 2022) Robinson, Peter M. W.
This article describes an approach to the treatment of texts in complex large textual traditions. Editors are interested in the text as it appears line-by-line in each document, and in how the versions of the text differ from document to document. It is useful to define a text as the record of an act of communication, inscribed in a document: thus, the instance of the act of communication we identify as Geoffrey Chaucer’s Canterbury Tales, as it appears in the Hengwrt manuscript. In this view, every text has a dual aspect: it is both the words as they are inscribed in a particular document, and as they constitute an act of communication and its parts. This presents challenges for scholars who wish to record both aspects. In encoding implementations, these two aspects are commonly treated as ‘overlapping hierarchies’. However, the ‘overlapping hierarchy’ model does not deal with cases where text segments are not contiguous in either aspect and cannot overlap cleanly. To meet these cases, the Textual Communities project developed an architecture in which the two aspects are represented as distinct and independent hierarchies (trees), with text segments referenced to nodes on each tree. The linking of text segments to the two trees is managed by a JSON database, accessed through transcription and collation tools presented in a Web interface. Textual Communities does not implement the whole of this architecture in terms of validation, ingestion, and processing. Full exploration and implementation of the architecture here described are challenges for future scholars.

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