Adoption of virtual reality technology in higher education: An evaluation of five teaching semesters in a purpose-designed laboratory.

Virtual and augmented (VAR) technology is in the early stages of being adopted as a teaching platform in higher education. The technology can facilitate immersive learning in environments that are not usually physically accessible to students via 3D models and interactive 360° videos. To date, adoption rates of VAR technology for teaching have not been well described across a higher education institution. Further, there is an absence of information on the optimal VAR laboratory designs and cost per student. In this study, a purpose designed virtual reality laboratory was formed in 2017 at The University of Sydney, housing 26 Oculus Rift headset units. An evaluation was conducted on the design, costs, rates of teaching adoption and student experiences over five teaching periods (2.5 years). Over this period, 4833 students were taught in the laboratory across 7952 student visits. The laboratory was used most by the Faculty of Engineering (53%), followed by the Faculty of Arts & Social Science (23.8%) and Faculty of Science (23.2%). For engineering, the units of study using the laboratory represented only 1.4% of annual faculty subjects offered. This confirms that adoption was in the initial stage of innovation diffusion. The laboratory saw a 250% increase in student numbers over the period of evaluation and 71.5% of students surveyed (n = 295) reported enhanced learning outcomes. The cost per visit was only AU$ 19.50. These findings give confidence to higher education institutions that the right VAR technology infrastructure is a sound educational investment for the future. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10639-021-10653-6.

Salt- and pH-Dependent Viscosity of SDS/LAPB Solutions: Experiments and a Semiempirical Thermodynamic Model.

We present novel data on the composition-, pH-, and salt-dependent zero shear viscosity of the commercially important mixture of anionic sodium dodecyl sulfate (SDS) and zwitterionic lauramidopropyl betaine (LAPB). We show via proton NMR experiments that the notionally zwitterionic LAPB exhibits a large pKa shift in the presence of SDS and can become partially cationic at formulation-relevant pH ranges of 4.5-6.0-that is, the binary system is effectively a ternary system. This has a pronounced effect on the viscosity of the system at low pH, especially if the fraction of LAPB is high. We use theoretical arguments to motivate a semiempirical but practical approach to model the viscosity of the mixtures using thermodynamic parameters such as the excess chemical potentials or activity coefficients of the surfactants. We demonstrate this using an augmented regular solution theory-based mixed micelle thermodynamic model and develop robust regression models using Bayesian approaches. We also show how the pKa shift from NMR experiments can be used to parameterize the thermodynamic model. This framework should be extensible to other arbitrary surfactant mixtures in the future and hence will be of broad interest for the development of surfactant formulations for household, personal care, and other applications.

Labour Management in Trial of Labour After Cesarean Delivery (TOLAC): A Gap Analysis and Quality Improvement Initiative.

OBJECTIVE: This quality improvement (QI) initiative was designed to identify gaps between evidence-based or hospital recommendations for trial of labour after cesarean delivery (TOLAC) labour management and clinical practice. METHODS: Viable, singleton pregnancies from January 1, 2016, to December 31, 2018, undergoing TOLAC were extracted from the electronic medical record. Sixty randomly selected charts were reviewed for (1) consent, (2) induction methods, (3) oxytocin use, (4) continuous fetal monitoring, (5) admission indication, (6) examination regularity, (7) duration of dystocia before decision to perform cesarean delivery (CD), and (8) maternal complications. RESULTS: The institutional vaginal birth after cesarean rate was 71%. Documented consent to TOLAC on admission was present in 50% of cases. Oxytocin augmentation was used in 38% of cases, and the median maximum dose was 4 mU/min (interquartile range [IQR] 3-7.5 mU/min). Delays in initiating oxytocin were identified in 47% of those patients. Decisions to deliver by cesarean were made after a median time of 5 hours and 40 minutes (IQR 3 hours and 30 minutes to 6 hours and 35 minutes) of failure to progress despite adequate contractions. After this decision, median time to delivery was 1 hour and 11 minutes (IQR 57 minutes to 2 hours and 16 minutes). Complications included postpartum hemorrhage (5%) and chorioamnionitis (6.7%). Surgical injury occurred in 10% of intrapartum CD. Peripartum complications were associated with delay in oxytocin implementation (χ2 (1) = 9.80; P < 0.001) in secondary analysis. CONCLUSION: Areas for QI were identified in (1) consent, (2) duration of dystocia before decision to proceed with CD and delay to CD, and (3) peripartum complications. We recognize the potential use of this as a tool to identify areas for QI and prospective study.

Directive clinique no 414 : Prise en charge des grossesses de localisation indéterminée et des grossesses ectopiques tubaires et non tubaires.

OBJECTIF: Fournir un algorithme fondé sur des données probantes pour orienter le diagnostic et la prise en charge de la grossesse de localisation indéterminée et de la grossesse ectopique tubaire ou non tubaire. POPULATION CIBLE: Toutes les patientes en âge de procréer. BéNéFICES, RISQUES ET COûTS: La mise en œuvre de la présente directive a pour objectif de bénéficier aux patientes ayant obtenu un résultat positif pour la sous-unité bêta de la gonadotrophine chorionique et de fournir aux médecins un algorithme normalisé pour l'expectative et le traitement pharmacologique ou chirurgical en cas de grossesse de localisation indéterminée et de grossesse ectopique tubaire ou non tubaire. DONNéES PROBANTES: Les termes de recherche suivants ont été entrés dans les bases de données PubMed-Medline et Cochrane en 2018 : cesarean section, chorionic gonadotropin, beta subunit, human/blood, fallopian tubes/surgery, female, fertility, humans, infertility, laparoscopy, methotrexate, methotrexate/administration & dosage, methotrexate/therapeutic use, pregnancy (abdominal, angular, cervix, cornual, ectopic, ectopic/diagnosis, ectopic/diagnostic imaging, ectopic/drug therapy, ectopic/epidemiology, ectopic/mortality, ectopic/surgery, heterotopic, interstitial, isthmo-cervical, ovarian, tubal, unknown location), recurrence, risk factors, salpingectomy, salpingostomy, tubal pregnancy, ultrasonography, doppler ultrasonography et prenatal. Les articles retenus sont des essais cliniques randomisés, des méta-analyses, des revues systématiques, des études observationnelles et des études de cas. Des publications supplémentaires ont été sélectionnées à partir des notices bibliographiques de ces articles. Seuls les articles en anglais ont été examinés. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la solidité des recommandations en utilisant la méthodologie GRADE (Grading of Recommendations Assessment, Development and Evaluation). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et faibles). PUBLIC VISé: Obstétriciens-gynécologues, médecins de famille, urgentologues, sages-femmes, infirmières autorisées, infirmières praticiennes, étudiants en médecine, résidents et moniteurs cliniques. DÉCLARATIONS SOMMAIRES (CLASSEMENT GRADE ENTRE PARENTHèSES): RECOMMANDATIONS (CLASSEMENT GRADE ENTRE PARENTHèSES).

Guideline No. 414: Management of Pregnancy of Unknown Location and Tubal and Nontubal Ectopic Pregnancies.

OBJECTIVE: To provide an evidence-based algorithm to guide the diagnosis and management of pregnancy of unknown location and tubal and nontubal ectopic pregnancy. TARGET POPULATION: All patients of reproductive age. BENEFITS, HARMS, AND COSTS: The implementation of this guideline aims to benefit patients with positive ß-human chorionic gonadotropin results and provide physicians with a standard algorithm for expectant, medical, and surgical treatment of pregnancy of unknown location and tubal pregnancy and nontubal ectopic pregnancies. EVIDENCE: The following search terms were entered into PubMed/Medline and Cochrane in 2018: cesarean section, chorionic gonadotropin, beta subunit, human/blood, fallopian tubes/surgery, female, fertility, humans, infertility, laparoscopy, methotrexate, methotrexate/administration & dosage, methotrexate/therapeutic use, pregnancy (abdominal, angular, cervix, cornual, ectopic, ectopic/diagnosis, ectopic/diagnostic imaging, ectopic/drug therapy, ectopic/epidemiology, ectopic/mortality, ectopic/surgery, heterotopic, interstitial, isthmo-cervical, ovarian, tubal, unknown location), recurrence, risk factors, salpingectomy, salpingostomy, tubal pregnancy, ultrasonography, doppler ultrasonography, and prenatal. Articles included were randomized controlled trials, meta-analyses, systematic reviews, observational studies, and case reports. Additional publications were identified from the bibliographies of these articles. Only English-language articles were reviewed. VALIDATION METHODS: The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations). INTENDED AUDIENCE: Obstetrician-gynaecologists, family physicians, emergency physicians, midwives, registered nurses, nurse practitioners, medical students, and residents and fellows. SUMMARY STATEMENTS (GRADE RATINGS IN PARENTHESES): RECOMMENDATIONS (GRADE RATINGS IN PARENTHESES).

Enthalpy and Entropy of Scission in Wormlike Micelles.

The free scission energy is the thermodynamic parameter that governs the contour length of wormlike micelles (WLMs). It is the contour length and the propensity to coil and entangle that determine the viscoelastic properties of this commercially important substance class. The free scission energy Δ Fsc and the associated change in enthalpy Δ Hsc and entropy Δ Ssc on scission have been determined for a mixed anionic/zwitterionic surfactant system (sodium laureth sulfate and cocamidopropyl betaine) at various salt concentrations (3-5 wt % NaCl). Both enthalpy Δ Hsc and entropy Δ Ssc changes decrease linearly with increasing NaCl concentration. At NaCl concentrations above 4 wt %, Δ Ssc even adopts negative values. The term TΔ Ssc decreases more rapidly than Δ Hsc around room temperature and causes the observed elongation of WLMs upon addition of NaCl. It is suggested that Δ Ssc is initially positive due to fewer bound counterions per surfactant molecule at end caps compared to the intact, cylindrical parts before scission, leading to a net release of ions upon scission. Negative values of Δ Ssc are attributed to hydrophobic hydration occurring at the end caps at high salt concentrations. 23Na NMR measurements indicate the presence of immobilized ions, supporting a previously proposed ion-cloud model based on neutron scattering results.

Locally produced hydrogen sulphide detecting water quality test kits increase household level monitoring in rural Tanzania.

In developing countries, rural water sources have the highest levels of faecal contamination but are the least monitored. Affordable field-based water quality tests are needed. The presence of faecal indicator bacteria can be determined with hydrogen sulphide (H2S) detecting tests, that are inexpensive and simple to make locally. In rural Tanzania, a non-governmental organisation (NGO) designed, produced and evaluated a new H2S water quality test kit. The H2S test results correlated with log10 Escherichia coli densities from conventional water quality tests. The production cost was US$ 1.10 and the test retailed for US$ 1.37. In total, 433 tests were sold through local pharmacies and NGOs. Additionally, 165 WaSH education meetings, reaching 3,408 community members, were conducted with the H2S test demonstrated in over half the meetings. Pre- and post-surveys of 294 meeting participants saw an increased reporting of household level water treatment by 24%. The H2S test was widely accepted, with 94% of those surveyed willing to buy the test in the future. International and national guidelines for drinking water monitoring need to be amended to include locally produced H2S water quality tests. This will enable households to monitor their own water sources and make informed choices about water safety and treatment.

Biomechanical Performance of Medial Row Suture Placement Relative to the Musculotendinous Junction in Transosseous Equivalent Suture Bridge Double-Row Rotator Cuff Repair.

PURPOSE: To compare the biomechanical performance of medial row suture placement relative to the musculotendinous junction (MTJ) in a cadaveric transosseous equivalent suture bridge (TOE-SB) double-row (DR) rotator cuff repair (RCR) model. METHODS: A TOE-SB DR technique was used to reattach experimentally created supraspinatus tendon tears in 9 pairs of human cadaveric shoulders. The medial row sutures were passed either near the MTJ (MTJ group) or 10 mm lateral to the MTJ (rotator cuff tendon [RCT] group). After the supraspinatus repair, the specimens underwent cyclic loading and load to failure tests. The localized displacement of the markers affixed to the tendon surface was measured with an optical tracking system. RESULTS: The MTJ group showed a significantly higher (P = .03) medial row failure (5/9; 3 during cyclic testing and 2 during load to failure testing) compared with the RCT group (0/9). The mean number of cycles completed during cyclic testing was lower in the MTJ group (77) compared with the RCT group (100; P = .07) because 3 specimens failed in the MTJ group during cyclic loading. There were no significant differences between the 2 study groups with respect to biomechanical properties during the load to failure testing. CONCLUSIONS: In a cadaveric TOE-SB DR RCR model, medial row sutures through the MTJ results in a significantly higher rate of medial row failure. CLINICAL RELEVANCE: In rotator cuff tears with tendon tissue loss, passage of medial row sutures through the MTJ should be avoided in a TOE-SB RCR technique because of the risk of medial row failure.

Ultraviolet-Fluorescent Tattoo Facilitates Accurate Identification of Biopsy Sites.

BACKGROUND: Cutaneous biopsy sites are often difficult to discern or are frequently misidentified when patients present for the treatment of skin cancers. This frustrating situation can lead to delays in treatment and wrong site surgeries. Current methods aiming to prevent this situation are not perfect. OBJECTIVE: This study seeks to determine the efficacy of ultraviolet-fluorescent tattoos in facilitating the correct identification of suspected nonmelanoma skin cancer biopsy sites. METHODS: In this prospective cohort, 51 shave biopsy sites were tattooed with ultraviolet-fluorescent ink in a series of 31 patients suspected of having a cutaneous malignancy. At the time of follow-up, the ability of the patient and the physician to identify the correct site with and without ultraviolet illumination of the tattoo was recorded. Visibility of the tattoo was graded before and after treatment. RESULTS: Patients could not positively identify their biopsy site in 35% of cases. In 7% of cases, physicians could not confidently identify the site without the aid of ultraviolet illumination. In conjunction with tattoo illumination, physicians confidently identified the site in 100% of the cases. No adverse events occurred. CONCLUSION: Ultraviolet-fluorescent tattoos offer a safe and reliable means of accurately marking cutaneous biopsy sites.

Conservative Management of Cervical Ectopic Pregnancy.

OBJECTIVE: To evaluate the safety and effectiveness of conservative management for cervical ectopic pregnancies. METHODS: We conducted a retrospective review of all cases of cervical ectopic pregnancy diagnosed at our tertiary care academic centre between January 2002 and July 2014. The diagnosis of cervical ectopic pregnancy was made using transvaginal ultrasound according to published criteria. Management decisions were made by individual clinicians. RESULTS: Cervical ectopic pregnancy was diagnosed in 27 women with a median age of 34 years. Two thirds of them were nulliparous, and 44% (12/27) reported infertility. The mean gestational age at diagnosis was seven weeks. The median serum human chorionic gonadotropin level was 11 300 IU/L (range 610 to 163 700). Fetal cardiac activity was present in 19 pregnancies (70%). Vaginal bleeding was the most common presentation, occurring in 23 cases (85%). Three women presented with acute life-threatening hemorrhage. All cases were successfully managed conservatively, allowing uterine preservation. Systemic methotrexate (single or multi-dose protocol) was the mainstay of therapy. Other minimally invasive interventions included ultrasound-guided injection of potassium chloride into the pregnancy, uterine artery embolization, vaginal ligation of cervical branches of the uterine arteries, and dilatation and curettage, with or without dilute vasopressin cervical infiltration and Foley catheter tamponade. CONCLUSION: Systemic methotrexate alone or in combination with other minimally invasive techniques can be effective conservative treatment for cervical pregnancies. A fertility-sparing approach is the optimal treatment for this patient population, which has high rates of infertility and nulliparity. We present a management algorithm based on our results to aid in standardizing the management of cervical ectopic pregnancies.

Objectif : Évaluer l'innocuité et l'efficacité de la prise en charge conservatrice des grossesses ectopiques cervicales. Méthodes : Nous avons mené une analyse rétrospective de tous les cas de grossesse ectopique cervicale diagnostiqués au sein de notre centre universitaire tertiaire entre janvier 2002 et juillet 2014. Le diagnostic de grossesse ectopique cervicale a été établi par échographie transvaginale, conformément aux critères publiés. Les décisions quant à la prise en charge ont été prises par les cliniciens concernés. Résultats : Une grossesse ectopique cervicale a été diagnostiquée chez 27 femmes (âge médian : 34 ans). Les deux tiers d'entre elles étaient nullipares et 44 % (12/27) ont signalé une infertilité. L'âge gestationnel moyen au moment du diagnostic était de sept semaines. Le taux sérique médian de gonadotrophine chorionique humaine était de 11 300 UI/l (plage : de 610 à 163 700). Une activité cardiaque fœtale était présente dans 19 grossesses (70 %). Les saignements vaginaux constituaient la présentation la plus courante; de tels saignements étaient présents dans 23 cas (85 %). Trois femmes ont connu une hémorragie aiguë constituant un danger de mort. Tous les cas ont fait l'objet d'une prise en charge conservatrice réussie qui a permis la préservation de l'utérus. Le méthotrexate administré par voie générale (protocole à dose unique ou à doses multiples) constituait l'élément principal du traitement. Parmi les autres interventions à effraction minimale, on trouvait l'injection (orientée par échographie) de chlorure de potassium dans la grossesse, l'embolisation des artères utérines, la ligature vaginale des rameaux cervicaux des artères utérines et la dilatation-curetage (avec ou sans infiltration cervicale de vasopressine diluée et tamponnement par sonde de Foley). Conclusion : Le recours à du méthotrexate administré par voie générale, seul ou en combinaison avec d'autres techniques à effraction minimale, peut constituer un traitement conservateur efficace en présence d'une grossesse cervicale. Une approche permettant de préserver la fécondité constitue le traitement optimal pour cette population de patientes, laquelle compte des taux élevés d'infertilité et de nulliparité. Nous présentons un algorithme de prise en charge fondé sur nos résultats dans le but de contribuer à la standardisation de la prise en charge des grossesses ectopiques cervicales.

Your garden hose: a potential health risk due to Legionella spp. growth facilitated by free-living amoebae.

Common garden hoses may generate aerosols of inhalable size (≤10 µm) during use. If humans inhale aerosols containing Legionella bacteria, Legionnaires' disease or Pontiac fever may result. Clinical cases of these illnesses have been linked to garden hose use. The hose environment is ideal for the growth and interaction of Legionella and free-living amoebae (FLA) due to biofilm formation, elevated temperatures, and stagnation of water. However, the microbial densities and hose conditions necessary to quantify the human health risks have not been reported. Here we present data on FLA and Legionella spp. detected in water and biofilm from two types of garden hoses over 18 months. By culturing and qPCR, two genera of FLA were introduced via the drinking water supply and reached mean densities of 2.5 log10 amoebae·mL(-1) in garden hose water. Legionella spp. densities (likely including pathogenic L. pneumophila) were significantly higher in one type of hose (3.8 log10 cells·mL(-1), p < 0.0001). A positive correlation existed between Vermamoebae vermiformis densities and Legionella spp. densities (r = 0.83, p < 0.028). The densities of Legionella spp. identified in the hoses were similar to those reported during legionellosis outbreaks in other situations. Therefore, we conclude that there is a health risk to susceptible users from the inhalation of garden hose aerosols.

Arginine Acts as both Co-solvent and Catalyst in Regioselective Eutectic-Mediated Dimerization of Levulinic Acid.

Invited for this issue's cover are Procter & Gamble's Corporate Analytical and Engineering Groups, along with the group of Professor Jovica Badjic and colleagues. The image, by Jennifer F. Neal, depicts the process of chemically upgrading the renewable, biomass-derived levulinic acid by simplying mixing it with l-arginine. The Research Article itself is available at 10.1002/cssc.202400503.

Arginine Acts as both Co-Solvent and Catalyst in Regioselective Eutectic-Mediated Dimerization of Levulinic Acid.

A simple, solvent-free arginine-catalyzed aldol dimerization of levulinic acid was achieved via the simultaneous formation of a eutectic mixture. Dimers of levulinic acid are valued as biomass-derived fine chemical precursors, with potential to upgrade to bio-jet fuels or N-containing functional chemicals. Typically, these dimers are produced as isomeric mixtures using high temperatures and a variety of solid inorganic catalysts or mineral acids. In this study, an organocatalytic and regioselective dimerization was achieved at 22 % conversion on either a bench or kilogram scale using mild temperatures and only L-arginine as both a co-solvent and catalyst. The intricate H-bonding network comprising the eutectic solvent was harnessed to produce only one product, minimizing side reactivity and preserving the reactants for recycling.

A spatial framework for improved sanitation to support coral reef conservation.

Coral reefs are one of the most valuable yet threatened ecosystems in the world. Improving human wastewater treatment could reduce land-based impacts on coral reefs. However, information on the quantity and spatial distribution of human wastewater pollution is lacking. Here, we develop a spatial model linking residential human wastewater pollution (nitrogen and phosphorus/year) and conservation sectors [coral reefs] to better understand the relative differences in the distribution and efficacy of different sanitation services and their potential implications for conservation monitoring and management. We apply our model to Fiji, where ongoing initiatives and investments in wastewater treatment for human health could be leveraged to cost-effectively improve coral reef condition. We estimate that wastewater treatment plants account for nearly 80% of human wastewater nutrients released into surface waters. Wasterwater nutrient pollution is widespread, affecting 95% of reefs, but is concentrated across a few watersheds. Our spatially explicit approach can be used to better understand potential benefits and trade-offs between sanitation service improvements and coral reef health, helping to bridge the sanitation and conservation sectors as well as inform and prioritize on the ground action.

Unearthing who and Y at Harewood Cemetery and inference of George Washington's Y-chromosomal haplotype.

An excavation conducted at Harewood Cemetery to identify the unmarked grave of Samuel Washington resulted in the discovery of burials presumably belonging to George Washington's paternal grandnephews and their mother, Lucy Payne. To confirm their identities this study examined Y-chromosomal, mitochondrial, and autosomal DNA from the burials and a living Washington descendant. The burial's Y-STR profile was compared to FamilyTreeDNA's database, which resulted in a one-step difference from the living descendant and an exact match to another Washington. A more complete Y-STR and Y-SNP profile from the descendant was inferred to be the Washington Y profile. Kinship comparisons performed in relation to the descendant, who is a 4th and 5th degree relative of the putative individuals, resulted in >37,000 overlapping autosomal SNPs and strong statistical support with likelihood ratios exceeding one billion. This study highlights the benefits of a multi-marker approach for kinship prediction and DNA-assisted identification of historical remains.

An assessment of latrine front-end characteristics and associated surface E. coli indicated faecal contamination in rural Fiji.

In Fiji, 90% of the population has access to basic sanitation; however, there are still persistent health risks from endemic faecal-oral diseases such as typhoid fever. There is a need to assess the contribution of existing sanitation facilities in the faecal pathogen transmission pathway. This study was conducted as part of a larger planetary health study across 29 rural communities within five river catchments. This specific research aimed to characterise latrine front-ends, both infrastructure and usage behaviour, and to assess the faecal contamination levels on various frequently contacted latrine surfaces in rural Fiji. A sanitation survey, along with observation and latrine swab sampling, was conducted in households over three phases: baseline (n = 311) (Aug-Dec 2019), endline (n = 262) (Jun-Sep 2022) and an in-depth front-end study (n = 12) (Oct-Nov 2022). Of 311 households, almost all had pedestal-type latrines, predominately cistern-flush (83%), followed by pour-flush (13%), and then hole-type (pit) latrines (4%). Washable latrine floors had significantly higher E. coli densities (6.7 × 102 CFU/25 cm2) compared to non-washable floors (1.3 × 102 CFU/25 cm2) (p = 0.05), despite washable floors indicating improved latrines. The in-depth front-end analysis found that moist latrine surfaces had significantly elevated E. coli densities (1.2 × 103 CFU/25 cm2) compared to the dry ones (14.3 CFU/25 cm2) (p < 0.001), highlighting the importance of maintaining dry latrine surfaces. Latrine floors and mid-walls were the most frequently contaminated surfaces, emphasising the need to clean and disinfect these surfaces. Only 46% of the households reported always using soap for handwashing after defecation, exacerbating the risk of transmitting faecal pathogens. This study highlights that latrine cleanliness and hygiene are as crucial as latrine infrastructures for the effective disruption of faecal pathogens transmission during latrine use.

A review of latrine front-end characteristics associated with microbial infection risk; reveals a lack of pathogen density data.

Unsafe sanitation accounts for an estimated 898,000 global deaths annually. The faecal pathogen transmission pathway is complex with several possible routes. Latrine front-end characteristics and usage behaviours are one key transmission pathway for microbial pathogens, however, there has not yet been a synthesis of the available research. This review aims to compare the microbial infection risks with latrine front-end components including any quantified microbial densities within the household latrines. This review was conducted with no restriction on the geographical location of the research. Of 118 studies reviewed, only ten (8%) have quantified the microbial density inside the household latrines compared to 109 (92%) measuring the infection risks. The reported risks were most frequent for specific bacterial (n = 34), and helminths infections (n = 32) compared to diarrhoea (n = 23), combined (n = 15), protozoan (n = 4), and viral (n = 4) infections. The infections risk decreased for using latrines lying at a higher position on the sanitation ladder (for example flush latrines) compared to those lying lower (for example pit latrines). The trend was similar for using floor materials that were easier to clean and less favourable for pathogen survival inside the latrines (for example, concrete as opposed to earth). Faecal coliforms were reported highest on the surface of the squat pan (743 CFU/cm2) of pour-flush latrines and helminths on earth floors of pit latrines (1.5 eggs and larvae per gram of soil). Irrespective of latrine type and its position on the sanitation ladder, a dirty latrine, evidenced by a visible lack of cleanliness, significantly increased the risk for all infections. This study recommends that effective microbial infection risk reduction in latrines can be gained efficiently by ensuring washable surfaces and consistent cleaning practices. Future studies should include more rigorous measurements of microbial densities in various latrine types incorporating the different front-end components and usage behaviours.

Evaluating the Usefulness of Human DNA Quantification to Predict DNA Profiling Success of Historical Bone Samples.

This study assessed the usefulness of DNA quantification to predict the success of historical samples when analyzing SNPs, mtDNA, and STR targets. Thirty burials from six historical contexts were utilized, ranging in age from 80 to 800 years postmortem. Samples underwent library preparation and hybridization capture with two bait panels (FORCE and mitogenome), and STR typing (autosomal STR and Y-STR). All 30 samples generated small (~80 bp) autosomal DNA target qPCR results, despite mean mappable fragments ranging from 55-125 bp. The qPCR results were positively correlated with DNA profiling success. Samples with human DNA inputs as low as 100 pg resulted in ≥80% FORCE SNPs at 10X coverage. All 30 samples resulted in mitogenome coverage ≥100X despite low human DNA input (as low as 1 pg). With PowerPlex Fusion, ≥30 pg human DNA input resulted in >40% of auSTR loci. At least 59% of Y-STR loci were recovered with Y-target qPCR-based inputs of ≥24 pg. The results also indicate that human DNA quantity is a better predictor of success than the ratio of human to exogenous DNA. Accurate quantification with qPCR is feasible for historical bone samples, allowing for the screening of extracts to predict the success of DNA profiling.