Cost-effectiveness of erosion mitigation to meet water clarity targets in the Manawatu-Whanganui Region of New Zealand.

Soil erosion is a significant environmental issue worldwide. It affects water quality, biodiversity, and land productivity. New Zealand government agencies and regional councils work to mitigate soil erosion through policies, management programmes, and funding for soil conservation projects. Information about cost-effectiveness is crucial for planning, targeting, and implementing erosion mitigation to achieve improvements in sediment-related water quality. While there is a good understanding of the costs of erosion mitigation measures, there is a dearth of literature on their cost-effectiveness in reducing sediment loads and improving water quality at the catchment level. In this study, we estimate the cost-effectiveness of erosion mitigation measures in meeting visual water clarity targets. The analysis utilizes the spatially explicit SedNetNZ erosion process and sediment budget modelling in the Manawatu-Whanganui Region and region-specific mitigation costs. The erosion mitigation measures considered in the analysis include afforestation, bush retirement, riparian retirement, space-planted trees, and gully tree planting. We modelled two scenarios with on-farm erosion mitigation implemented across the region from 2021 to 2100, resulting in a 48% and 60% reduction of total sediment load. We estimate the marginal costs to achieve the visual national bottom line for water clarity, as assessed by the length of waterways that meet the clarity targets. We also estimate the marginal costs of improving average water clarity, which can be linked with non-market valuation studies when conducting a cost-benefit analysis. We find that gully tree planting and space-planted trees are the most cost-effective mitigation measures and that riparian retirement is the least cost-effective. Moreover, cost-effectiveness is highly dependent on current land use and the biophysical features of the landscape. Our estimates can be used in cost-benefit analysis to plan and prioritize soil erosion mitigation at the catchment and regional levels.

Orthopedic Surgery and Anesthesiology Surgical Improvement Strategies Project - Phase III Outcomes.

BACKGROUND: Our institution initiated the Orthopedic Surgery and Anesthesiology Surgical Improvement Strategies (OASIS) project in 2017 to improve the quality and efficiency for hip and knee arthroplasties. Phase III of this project aimed to: 1) increase same-day discharge (SDD) of primary total joint arthroplasties (TJAs) to 20%; 2) maintain or improve 30-day readmission rates; and 3) realize cost savings and revenue increases. METHODS: All primary TJAs performed between 2021 and 2022 represented our study cohort, with those in 2019 (prepandemic) establishing the baseline cohort. A multidisciplinary team met weekly to track project tactics and metrics through the entire episode of care from preoperative surgical visit through 30 days postoperatively. RESULTS: The SDD rate increased from 4% at baseline to 37%, with mean lengths of stay (LOS) decreasing from 1.5 to 0.9 days for all primary TJAs. The 30-day readmission rate decreased to 1.2 from 1.3%. Composite changes in surgical volume and cost reductions equaled $5 million. CONCLUSION: Application of a multidisciplinary team with health systems engineering tools and methods allowed SDD to increase from 4 to 37% with a mean LOS <1 day, resulting in a $5 million incremental gain in profit at a major academic medical center. Importantly, patient safety was not compromised as 30-day readmission rates remained stable. LEVEL OF EVIDENCE: III Therapeutic.

Spinal Versus General Anesthesia in Contemporary Revision Total Knee Arthroplasties.

BACKGROUND: Interest in spinal anesthesia utilization in revision total knee arthroplasties (TKAs) is rising. This study investigated the pain control, length of stay (LOS), and complications associated with spinal versus general anesthesia in a single institution series of revision TKAs. METHODS: We identified 3,711 revision TKAs (3,495 patients) from 2001 to 2016 using our institutional total joint registry. There were 66% who had general anesthesia and 34% who had spinal anesthesia. Mean age, sex, and BMI were similar between groups at 67 years, 53% women, and 32, respectively. Data were analyzed using inverse probability of treatment weighted models based on propensity scores that accounted for patient and operative factors. Mean follow-up was 6 years (range, 2 to 17). RESULTS: Patients treated with spinal anesthesia required fewer postoperative oral morphine equivalents (OMEs) (P < .0001) and had lower numeric pain rating scale scores (P < .001). Spinal anesthesia was associated with shorter LOS (4.0 versus 4.6 days; P < .0001), less cases of altered mental status (AMS; Odds Ratio (OR) 2.0, P = .004), less intensive care unit (ICU) admissions (OR 1.6, P = .02), fewer re-revisions (OR 1.7, P < .001), and less reoperations (OR 1.4, P < .001). There was no difference in the incidence of VTE (P = .82), 30-day readmissions (P = .06), or 90-day readmissions (P = .18) between anesthetic techniques. CONCLUSION: We found that spinal anesthesia for revision TKAs was associated with significantly lower pain scores, reduced OME requirements, and decreased LOS. Furthermore, spinal anesthesia was associated with fewer cases of AMS, ICU admissions, and re-revisions even after accounting for numerous patient and operative factors. LEVEL OF EVIDENCE: Level III, Retrospective Comparative Study.

Spinal Versus General Anesthesia in Contemporary Revision Total Hip Arthroplasties.

BACKGROUND: Spinal anesthesia is increasingly used in complex patient populations including revision total hip arthroplasties (THAs). This study aimed to investigate the pain control, length of stay (LOS), and complications associated with spinal versus general anesthesia in a large institutional series of revision THAs. METHODS: We retrospectively identified 4,767 revision THAs (4,533 patients) from 2001 to 2016 using our institutional total joint registry. Of these cases, 86% had general and 14% had spinal anesthesia. Demographics between groups were similar with mean age of 66 years, 52% women, and mean body mass index of 29. Complications including all-cause rerevisions and reoperations were studied. Data were analyzed using an inverse probability of treatment weighted model based on propensity score that accounted for patient and surgical factors. The mean follow-up was 7 years. RESULTS: Patients treated with spinal anesthesia required fewer postoperative oral morphine equivalents (P < .001) and had lower numeric pain rating scale scores (P < .001). Spinal anesthesia had a decreased LOS (4.2 versus 4.8 days; P = .007), fewer cases of altered mental status (odds ratio (OR) 3.1, P = .001), fewer blood transfusions (OR 2.3, P < .001), fewer intensive care unit admissions (OR 2.3, P < .001), fewer rerevisions (OR 1.6, P = .04), and fewer reoperations (OR 1.5, P = .02). CONCLUSION: Spinal anesthesia was associated with lower oral morphine equivalent use and reduced LOS in this large cohort of revision THAs. Furthermore, spinal anesthesia was associated with fewer cases of altered mental status, transfusion, intensive care unit admission, rerevision, and reoperation after accounting for numerous patient and operative factors. LEVEL OF EVIDENCE: Level III, Retrospective Comparative Study.

The role of the IT-state in D76N ß2-microglobulin amyloid assembly: A crucial intermediate or an innocuous bystander?

The D76N variant of human ß2-microglobulin (ß2m) is the causative agent of a hereditary amyloid disease. Interestingly, D76N-associated amyloidosis has a distinctive pathology compared with aggregation of WT-ß2m, which occurs in dialysis-related amyloidosis. A folding intermediate of WT-ß2m, known as the IT-state, which contains a nonnative trans Pro-32, has been shown to be a key precursor of WT-ß2m aggregation in vitro However, how a single amino acid substitution enhances the rate of aggregation of D76N-ß2m and gives rise to a different amyloid disease remained unclear. Using real-time refolding experiments monitored by CD and NMR, we show that the folding mechanisms of WT- and D76N-ß2m are conserved in that both proteins fold slowly via an IT-state that has similar structural properties. Surprisingly, however, direct measurement of the equilibrium population of IT using NMR showed no evidence for an increased population of the IT-state for D76N-ß2m, ruling out previous models suggesting that this could explain its enhanced aggregation propensity. Producing a kinetically trapped analog of IT by deleting the N-terminal six amino acids increases the aggregation rate of WT-ß2m but slows aggregation of D76N-ß2m, supporting the view that although the folding mechanisms of the two proteins are conserved, their aggregation mechanisms differ. The results exclude the IT-state as the origin of the rapid aggregation of D76N-ß2m, suggesting that other nonnative states must cause its high aggregation rate. The results highlight how a single substitution at a solvent-exposed site can affect the mechanism of aggregation and the resulting disease.

The effects of shoulder arthroscopy on ultrasound image quality of the interscalene brachial plexus: a pre-procedure vs post-procedure comparative study.

BACKGROUND: Fluid extravasation from the shoulder compartment and subsequent absorption into adjacent soft tissue is a well-documented phenomenon in arthroscopic shoulder surgery. We aimed to determine if a qualitative difference in ultrasound imaging of the interscalene brachial plexus exists in relation to the timing of performing an interscalene nerve block (preoperative or postoperative). METHODS: This single-center, prospective observational study compared pre- and postoperative interscalene brachial plexus ultrasound images of 29 patients undergoing shoulder arthroscopy using a pretest-posttest methodology where individual patients served as their own controls. Three fellowship-trained regional anesthesiologists evaluated image quality and confidence in performing a block for each ultrasound scan using a five-point Likert scale. The association of image quality with age, gender, BMI, duration of surgery, obstructive sleep apnea, and volume of arthroscopic irrigation fluid were analyzed as secondary outcomes. RESULTS: Aggregate preoperative mean scores in quality of ultrasound visualization were higher than postoperative scores (preoperative 4.5 vs postoperative 3.8; p < .001), as was confidence in performing blockade based upon the imaging (preoperative 4.8 vs postoperative 4.2; p < .001). Larger BMI negatively affected visualization of the brachial plexus in the preoperative period (p < 0.05 for both weight categories). Patients with intermediate-high risk or confirmed obstructive sleep apnea had lower aggregate postoperative mean scores compared to the low-risk group for both ultrasound visualization (3.4 vs 4.0; p < .05) and confidence in block performance (3.8 vs 4.4; p < .05). CONCLUSION: Due to the potential reduction of ultrasound visualization of the interscalene brachial plexus after shoulder arthroscopy, we advocate for a preoperative interscalene nerve block when feasible. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT03657173 ; September 4, 2018).

Orthopedic Surgery and Anesthesiology Surgical Improvement Strategies Project-Phase II Outcomes.

BACKGROUND: Our institution previously initiated a perioperative surgical home initiative to improve quality and efficiency across the hospital arc of care of primary total knee arthroplasty and total hip arthroplasty patients. Phase II of this project aimed to (1) expand the perioperative surgical home to include revision total hip arthroplasties and total knee arthroplasties, hip preservation procedures, and reconstructions after oncologic resections; (2) expand the project to include the preoperative phase; and (3) further refine the perioperative surgical home goals accomplished in phase I. METHODS: Phase II of the Orthopedic Surgery and Anesthesiology Surgical Improvement Strategies project ran from July 2018 to July 2019. The evaluated arc of care spanned from the preoperative surgical consult visit through 90 days postoperative in the expanded population described above. RESULTS: Mean length of stay decreased from 2.2 days to 2.0 days (P < .001), 90-day readmission decreased from 3.0% to 1.6% (P < .001), and Press-Ganey scores increased from 77.1 to 79.2 (97th percentile). Mean and maximum pain scores and opioid consumption remained unchanged (lowest P = .31). Annual surgical volume increased by 10%. Composite changes in surgical volume and cost reductions equaled $5 million. CONCLUSION: Application of previously successful health systems engineering tools and methods in phase I of Orthopedic Surgery and Anesthesiology Surgical Improvement Strategies enabled additional evolution of an orthopedic perioperative surgical home to encompass more diverse and complex patient populations while increasing system-wide quality, safety, and financial outcomes. Improved process and outcomes metrics reflected increased efficiency across the episode of care without untoward effects. LEVEL OF EVIDENCE: III Therapeutic.

Orthopedic Surgery and Anesthesiology Surgical Improvement Strategies Project: Phase I Outcomes.

BACKGROUND: This study aimed to improve institutional value-based patient care processes, provider collaboration, and continuous process improvement mechanisms for primary total hip arthroplasties and total knee arthroplasties through establishment of a perioperative orthopedic surgical home. METHODS: On June 1, 2017, an institutionally sponsored initiative commenced known as the orthopedic surgery and anesthesiology surgical improvement strategy project. A multidisciplinary team consisting of orthopedic surgeons, anesthesiologists, advanced practice providers, nurses, pharmacists, physical therapists, social workers, and hospital administration met regularly to identify areas for improvement in the preoperative, intraoperative, and post-anesthesia care unit, and postoperative phases of care. RESULTS: Mean hospital length of stay decreased from 2.7 to 2.2 days (P < .001), incidence of discharge to a skilled nursing facility decreased from 24% to 17% (P = .008), and the number of patients receiving physical therapy on the day of surgery increased from 10% to 100% (P < .001). Press-Ganey scores increased from 74.9 to 75.8 (94th percentile), while mean and maximum pain scores, opioid consumption, and hospital readmission rates remained unchanged (lowest P = .29). Annual total hip arthroplasty and total knee arthroplasty surgical volume increased by 11.4%. Decreased hospital length of stay and increased surgical volume yielded a combined annual savings of $2.5 million across the 9 involved orthopedic surgeons. CONCLUSION: Through application of perioperative surgical home tools and concepts, key advances included phase of care integration, enhanced data management, decreased length of stay, coordinated perioperative management, increased surgical volume without personnel additions, and more efficient communication and patient care flow across preoperative, intraoperative, and postoperative phases. LEVEL OF EVIDENCE: III Therapeutic.

Quantifying the influence of individual trees on slope stability at landscape scale.

Silvopastoralism in New Zealand's highly erodible hill country is an important form of erosion and sediment control. Yet, there has been little quantitative work to establish the effectiveness of space-planted trees in reducing shallow landslide erosion. We propose a method to provide high-resolution spatially explicit individual tree influence models at landscape scale for the dominant species in pastoral hill country. The combined hydrological and mechanical influence of trees on slopes is inferred through the spatial relationship between trees and landslide erosion. First, we delineate individual tree crowns and classify these into four dominant species classes found in New Zealand's pastoral hill country. This is the first species classification of individual trees at landscape scale in New Zealand using freely accessible data, achieving an overall accuracy of 92.6%. Second, we develop tree influence models for each species class by means of inductive inference. The inferred empirical tree influence models largely agree with the shape and distribution of existing physical root reinforcement models. Of exotic species that were planted for erosion and sediment control, poplars (Populus spp.) and willows (Salix spp.) make up 51% (109,000 trees) in pastoral hill country at a mean density of 3.2 trees/ha. In line with previous studies, poplars and willows have the greatest contribution to slope stability with an average maximum effective distance of 20 m. Yet, native kanuka (Kunzea spp.) is the most abundant woody vegetation species in pastoral hill country within the study area, with an average of 24.1 stems per ha (sph), providing an important soil conservation function. A large proportion (56% or 212.5 km2) of pastoral hill-country in the study area remains untreated. The tree influence models presented in this study can be integrated into landslide susceptibility modelling in silvopastoral landscapes to both quantify the reduction in landslide susceptibility achieved and support targeted erosion and sediment mitigation plans.

The Role of the Private Sector in Supporting Malaria Control in Resource Development Settings.

Industrial operations of the private sector, such as extraction, agriculture, and construction, can bring large numbers of people into new settlement areas and cause environmental change that promotes the transmission of vector-borne diseases. Industry-related workers and communities unduly exposed to infection risk typically lack the knowledge and means to protect themselves. However, there is a strong business rationale for protecting local resident employees through integrated vector control programs, as well as an ethical responsibility to care for these individuals and the affected communities. We discuss the role and challenges of the private sector in developing malaria control programs, which can include extensive collaborations with the public sector that go on to form the basis of national vector control programs or more broadly support local healthcare systems.

Flight activity and glycogen depletion on a low-carbohydrate diet.

Glycogen is a critical store for locomotion. Depleted glycogen stores are associated with increased fatigue during exercise. The reduced effectiveness of low-carbohydrate diets for weight loss over longer time periods may arise because such diets reduce glycogen stores and thereby energy expenditure via physical activity. To explore the effect of a low-carbohydrate diet on activity and glycogen utilisation, we fed adult Drosophila melanogaster a standard or low-carbohydrate diet for 9 days and measured patterns of flight activity and rates of glycogen depletion. We hypothesised that flight activity and rates of glycogen depletion would be reduced on a low-carbohydrate diet. Flight activity was elevated in the low-carbohydrate group but glycogen depletion rates were unchanged. We conclude that increased activity is probably a foraging response to carbohydrate deficiency and speculate that the previously demonstrated metabolic depression that occurs on a low-carbohydrate diet in this species may allow for increased flight activity without increased glycogen depletion.

Ty-6, a major begomovirus resistance gene on chromosome 10, is effective against Tomato yellow leaf curl virus and Tomato mottle virus.

KEY MESSAGE: Ty-6 is a major resistance gene on chromosome 10 of tomato that provides resistance against monopartite and bipartite begomoviruses and complements resistance conferred by the known Ty-3 and ty-5 genes. Resistance to monopartite and bipartite begomoviruses is an important breeding objective for cultivated tomato. Several begomovirus resistance genes have been introgressed from related Solanum species and are available for breeding purposes. In the present study, we mapped an additional locus, Ty-6, to chromosome 10 of tomato. Ty-6 is effective against both monopartite Tomato yellow leaf curl virus (TYLCV) and bipartite Tomato mottle virus (ToMoV). Gene action is incomplete dominance, with an intermediate resistance response when Ty-6 is heterozygous. Analysis of populations segregating for Ty-6 along with Ty-3 or ty-5 indicates that the highest level of resistance against TYLCV is attained when Ty-6 is combined with an additional resistance allele. Our results also demonstrate that ty-5 is ineffective against ToMoV. Although multiple SNPs linked to Ty-6 were identified and can be used for breeding purposes, none of these were consistently polymorphic between Ty-6 and ty-6 breeding lines. Further research is underway to generate resequencing data for several Ty-6 inbred lines for the discovery of additional sequence polymorphisms that can be used for fine mapping and characterizing the Ty-6 locus.

Transport and Redistribution of Radiocesium in Fukushima Fallout through Rivers.

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident released the most significant quantity of radiocesium into the environment since Chernobyl, and detailed measurements over the initial 5 years provide new insights into fluvial redistribution of radiocesium. We found that the high initial activity concentration of 137Cs-bearing suspended sediment in rivers was followed by a steep exponential decline (λ1) which extended to approximately 1 year after the accident, while the rate of initial decline in radiocesium activity concentration in water was an order of magnitude higher than rates measured after Chernobyl. Fluvial transport of 137Cs to the ocean from the Abukuma river totaled 12 TBq between June 2011 and August 2015 and almost all this radiocesium (96.5%) was transported in the particulate form. The primary sources of 137Cs were paddy fields, farmland, and urban areas [plaque-forming unit (PFU)], discharging 85% of the exported 137Cs from 38% of the watershed area. After 1 year, activity concentrations were lower and exhibited a more gradual secondary decline (λ2) which was associated with reduced radiocesium losses from PFU areas, while forest areas continue to represent more stable contaminant stores.

Peripheral electrical stimulation reduces postoperative hypoxemia in patients at risk for obstructive sleep apnea: a randomized-controlled trial.

PURPOSE: Severity of hypoxemic events resulting from obstructive sleep apnea (OSA) is correlated with increased risk of complications and sudden death. We studied the use of a peripheral transcutaneous electrical stimulus (TES) on the magnitude and duration of sleep apnea associated hypoxemia in postoperative patients at high risk for OSA. METHODS: In this randomized, double-blind, controlled, single-centre trial, 106 adult patients undergoing elective surgery who were at medium to high risk for OSA (sleep apnea clinical scores of 18-35) were randomized to either TES (active stimulus group, n = 53) or control (non-stimulus group, n = 53) during their stay in the postanesthesia care unit. Transcutaneous electrical stimuli were delivered at threshold oxygen saturation measurements (SpO2) ≤ 93%. The primary endpoint was the SpO2 area under the curve (AUC) < 90%. Secondary endpoints included the percentage of patients with SpO2 < 90%, duration SpO2 < 90%, lowest SpO2 in the first hour, and adverse events associated with TES. RESULTS: Compared with controls (n = 45), those in the active group (n = 34) showed a decreased SpO2 AUC < 90% (median 0.0 vs 15.2 % sec, respectively; P = 0.009), a smaller percentage of subjects with SpO2 < 90% (47% active vs 71% control; P = 0.03), a shorter duration of SpO2 < 90% (median 0.0 vs 19.1 sec, respectively; P = 0.01), and a higher nadir of SpO2 recorded during the first hour (median 90.5% vs 87.9%, respectively; P = 0.04). Among patients with at least one SpO2 < 93%, there were fewer with SpO2 < 90% in the active group (55% vs 84%, respectively; P = 0.009). No adverse events related to TES were reported. CONCLUSION: In postoperative surgical patients at risk for OSA, peripheral transcutaneous electrical stimulation applied during apneic episodes decreased the duration and magnitude of hypoxemia. TRIAL REGISTRATION: www.ClinicalTrials.gov (NCT02554110); registered 18 September, 2015.

Interspace between Popliteal Artery and posterior Capsule of the Knee (IPACK) Injectate Spread: A Cadaver Study.

OBJECTIVES: Local anesthetic injection into the interspace between the popliteal artery and the posterior capsule of the knee (IPACK) has the potential to provide motor-sparing analgesia to the posterior knee after total knee arthroplasty. The primary objective of this cadaveric study was to evaluate injectate spread to relevant anatomic structures with IPACK injection. METHODS: After receipt of Institutional Review Board Biospecimen Subcommittee approval, IPACK injection was performed on fresh-frozen cadavers. The popliteal fossa in each specimen was dissected and examined for injectate spread. RESULTS: Ten fresh-frozen cadaver knees were included in the study. Injectate was observed to spread in the popliteal fossa at a mean ± SD of 6.1 ± 0.7 cm in the medial-lateral dimension and 10.1 ± 3.2 cm in the proximal-distal dimension. No injectate was noted to be in contact with the proximal segment of the sciatic nerve, but 3 specimens showed injectate spread to the tibial nerve. In 3 specimens, the injectate showed possible contact with the common peroneal nerve. The middle genicular artery was consistently surrounded by injectate. CONCLUSIONS: This cadaver study of IPACK injection demonstrated spread throughout the popliteal fossa without proximal sciatic involvement. However, the potential for injectate to spread to the tibial or common peroneal nerve was demonstrated. Consistent surrounding of the middle genicular artery with injectate suggests a potential mechanism of analgesia for the IPACK block, due to the predictable relationship between articular sensory nerves and this artery. Further study is needed to determine the ideal site of IPACK injection.

Assessing the Temporal Effects of Squash vein yellowing virus Infection on Settling and Feeding Behavior of Bemisia tabaci (MEAM1) (Hemiptera: Aleyrodidae).

Insect vector behavior and biology can be affected by pathogen-induced changes in the physiology and morphology of the host plant. Herein, we examined the temporal effects of Squash vein yellowing virus (family Potyviridae, genus Ipomovirus) infection on the settling, oviposition preference, and feeding behavior of its whitefly vector, Bemisia tabaci (Gennadius) Middle East-Asia Minor 1 (MEAM1), formerly known as B. tabaci biotype B. Settling and oviposition behavioral choice assays were conducted on pairs of infected and mock-inoculated watermelon (Citrullus lanatus (Thunb) Matsum and Nakai) (Cucurbitales: Cucurbitaceae) at 5-6 days post inoculation (DPI) and 10-12 DPI. Electropenetrography, or electrical penetration graph (both abbreviated EPG), was used to assess differences in feeding behaviors of whitefly on mock-inoculated, 5-6 and 10-12 DPI infected watermelon plants. Whiteflies showed no preference in settling or oviposition on the infected and mock-inoculated plants at 5-6 DPI. However, at 10-12 DPI, whiteflies initially settled on infected plants but then preference of settling shifted to mock-inoculated plants after 8 h. Only at 10-12 DPI, females laid significantly more eggs on mock-inoculated plants than infected plants. EPG revealed no differences in whitefly feeding behaviors among mock-inoculated, 5-6 DPI infected and 10-12 DPI infected plants. The results highlighted the need to examine plant disease progression and its effect on vector behavior and performance, which could play a crucial role in Squash vein yellowing virus spread.

Short-duration respirometry underestimates metabolic rate for discontinuous breathers.

Metabolic rate is commonly estimated from rates of gas exchange. An underappreciated factor that can influence estimates is patterns of pulmonary respiration. Amphibians display discontinuous respiratory patterns, often including long apnoeas, in addition to cutaneous gas exchange. The contribution of cutaneous exchange increases at low temperatures when metabolic rate is low. Because of the relatively low permeability of skin, measurements that disproportionately capture cutaneous exchange can produce underestimates of metabolic rate. The permeability of amphibian skin to CO2 is greater than that to O2; therefore, calculating the ratio of whole-animal CO2 emission to O2 uptake (the respiratory exchange ratio, RER) can be used to avoid underestimates of metabolic rate by ensuring that observed values of RER fall within the normal physiological range (∼0.7 to 1). Using data for cane toads, Rhinella marina, we show that short-duration measurements lead to underestimates of metabolic rate and overestimates of RER. At low temperatures, this problem is exacerbated, requiring over 12 h for RER to fall within the normal physiological range. Many published values of metabolic rate in animals that utilise cutaneous exchange may be underestimates.

Clinical implications of de Barsy syndrome.

BACKGROUND: De Barsy syndrome is a rare, autosomal recessive syndrome characterized by cutis laxa, progeroid appearance, ophthalmic opacification, skeletal malformations, growth delays, and intellectual disability. AIMS: The aim of this case series is to identify the anesthetic considerations in the clinical management of patients with de Barsy syndrome. METHODS: A retrospective case review from 1968 to 2016 was performed at a single tertiary medical center to identify patients with de Barsy syndrome who underwent anesthesia for diagnostic and surgical procedures. We collected and analyzed the perioperative records and following data: age, sex, American Society of Anesthesiologists physical status, relevant comorbidities, surgical procedures, anesthesia management, and observed complications. RESULTS: Three patients underwent 64 unique anesthetics for a diverse collection of diagnostic and surgical procedures. An array of anesthetics and techniques were successfully used. Observations of the perioperative period found 7 episodes of intraoperative hyperthermia (>38.3°), a single difficult airway requiring fiberoptic bronchoscopic-guided intubation, and repeatedly difficult intravenous access. CONCLUSION: This expanded case series suggests that providers caring for patients with de Barsy syndrome should be aware of potential challenges with airway management, vascular access, and temperature monitoring.

How clean is your house? A study of house dust mites, allergens and other contents of dust samples collected from households.

Household dust contains an array of constituents, including house dust mites (HDM) and the HDM allergen, Der p 1, which can cause sensitivities such as asthma and eczema. Vacuuming can help alleviate symptoms, yet little is understood about cleaning behaviour in different households. This pilot study investigated the contents of dust from four household types (students; over 65 s; and families with and without pets). This was then related to cleaning behaviours and perceptions of cleanliness. Our investigation found that HDMs and Der p 1 were present in all households and sampling locations, including participants' cars. The median Der p 1 was greatest in the living room, though results varied. Demographic group was a determinant for the number of human and pet hairs present in dust. Surprisingly, vacuuming was the most disliked task overall. This information requires consideration when developing cleaning products and advising individuals with dust-related health issues.

Low-carbohydrate diet induces metabolic depression: a possible mechanism to conserve glycogen.

Long-term studies have found that low-carbohydrate diets are more effective for weight loss than calorie-restricted diets in the short term but equally or only marginally more effective in the long term. Low-carbohydrate diets have been linked to reduced glycogen stores and increased feelings of fatigue. We propose that reduced physical activity in response to lowered glycogen explains the diminishing weight loss advantage of low-carbohydrate compared with low-calorie diets over longer time periods. We explored this possibility by feeding adult Drosophila melanogaster a standard or a low-carbohydrate diet for 9 days and measured changes in metabolic rate, glycogen stores, activity, and body mass. We hypothesized that a low-carbohydrate diet would cause a reduction in glycogen stores, which recover over time, a reduction in physical activity, and an increase in resting metabolic rate. The low-carbohydrate diet reduced glycogen stores, which recovered over time. Activity was unaffected by diet, but metabolic rate was reduced, in the low-carbohydrate group. We conclude that metabolic depression could explain the decreased effectiveness of low-carbohydrate diets over time and recommend further investigation of long-term metabolic effects of dietary interventions and a greater focus on physiological plasticity within the study of human nutrition.