Search

Extracorporeal membrane oxygenation is increasingly being used to support patients with hypoxemic respiratory failure and cardiogenic shock. During the COVID‐19 pandemic, consensus guidance recommended extracorporeal life support for patients with COVID‐19‐related cardiopulmonary disease refractory to optimal conventional therapy, prompting a substantial expansion in the use of this support modality. Extracorporeal membrane oxygenation was particularly integral to the bridging of COVID‐19 patients to heart or lung transplantation. Limited human and physical resources precluded widespread utilization of mechanical support during the COVID‐19 pandemic, necessitating careful patient selection and optimal management by expert healthcare teams for judicious extracorporeal membrane oxygenation use. This review outlines the evidence supporting the use of extracorporeal life support in COVID‐19, describes the practice and outcomes of extracorporeal membrane oxygenation for COVID‐19‐related respiratory failure and cardiogenic shock, and proposes lessons learned for the implementation of extracorporeal membrane oxygenation as a bridge to transplantation in future public health emergencies. [ABSTRACT FROM AUTHOR]

Animals sense chemical cues such as nutritious and noxious stimuli through the chemosensory system and adapt their behavior, physiology, and developmental schedule to the environment. In the Drosophila central nervous system, chemosensory interneurons that produce neuropeptides called Hugin (Hug) peptides receive signals from gustatory receptor neurons and regulate feeding behavior. Because Hug neurons project their axons to the higher brain region within the protocerebrum where dendrites of multiple neurons producing developmentally important neuropeptides are extended, it has been postulated that Hug neurons regulate development through the neuroendocrine system. In this study, we show that Hug neurons interact with a subset of protocerebrum neurons that produce prothoracicotropic hormone (PTTH) and regulate the onset of metamorphosis and systemic growth. Loss of the hug gene and silencing of Hug neurons caused a delay in larval‐to‐prepupal transition and an increase in final body size. Furthermore, deletion of Hug receptor‐encoding genes also caused developmental delay and body size increase, and the phenotype was restored by expressing Hug receptors in PTTH‐producing neurons. These results indicate that Hug neurons regulate developmental timing and body size via PTTH‐producing neurons. This study provides a basis for understanding how chemosensation is converted into neuroendocrine signaling to control insect growth and development. [ABSTRACT FROM AUTHOR]

Background: Absent "organic" disease, dyspeptic symptoms may arise from abnormal gastric sensation, accommodation, motility or emptying (GE). Extensive gastric sensorimotor evaluation is rarely undertaken because testing is prolonged, invasive, poorly tolerated or unavailable. Aims: To investigate whether gastric antral motor function, evaluated with scintigraphy, predicts GE. To explore whether motor testing with symptom recording predicts day‐to‐day symptoms in patients with dyspepsia. Methods: GE was determined using a scintigraphic solid‐meal protocol (296 kcal, 35% fat). Antral motility was estimated from 10 min of scintigraphic time‐activity curves acquired 40 min after meal consumption. An antral motility index (MI) was derived from contraction amplitude and frequency. Intra‐gastric distribution of the meal on scintograms at 1 h (IGD1) was determined. Meal‐induced symptoms were evaluated by questionnaire. Patients completed the Gastroparesis Cardinal Symptom Index Daily Diary (GCSI‐DD) for 14 days. Results: Twelve healthy participants and 23 prospectively recruited patients completed the study. Nine patients had delayed, and 2 had rapid, GE. In univariate analysis MI explained 42% of GE half‐time. In multivariate analysis MI and GE half‐time explained 25% of the variance in meal‐induced symptoms. While scintigraphic evaluation of gastric motor function with symptom recording explained 80% of the variance in the GCSI‐DD, meal‐induced symptoms were the only significant predictor. However, among patients with delayed GE, MI, GE half‐time, IGD1, and meal‐induced symptoms all significantly predicted GCSI‐DD. Conclusions: Antral motility predicts GE. In exploratory analyses, only meal‐induced symptoms predicted daily symptoms among patients with dyspepsia. However, motor function also predicted symptoms in patients with delayed GE. [ABSTRACT FROM AUTHOR]

In Australia, acute inpatient units within public mental health services have become the last resort for mental health care. This research explored barriers and facilitators to safe, person‐centred, recovery‐oriented mental health care in these settings. It utilised participant observations conducted by mental health nurses in acute inpatient units. These units were located in three distinct facilities, each serving different areas: a large metropolitan suburban area in a State capital, a mid‐sized regional city, and a small city with a large rural catchment area. Our findings highlighted that, in the three inpatient settings, nurses tended to avoid common areas they shared with consumers, except for brief, task‐related visits. The prioritisation of administrative tasks seemed to arise in a situation where nurses lacked awareness of alternative practices and activities. Consumers spent prolonged periods of the day sitting in communal areas, where the main distraction was watching television. Boredom was a common issue across these environments. The nursing team structure in the inpatient units provided a mechanism for promoting a sense of psychological safety for staff and were a key element in how safety culture was sustained. [ABSTRACT FROM AUTHOR]

An updated position paper on critical care pharmacy services recommends the development of new clinical programs. However, proposed pragmatic strategies for critical care pharmacy practice advancement are lacking. The purpose of this position paper is to develop consensus recommendations aimed at direct patient care activities for the advancement of critical care pharmacy practice. A 24‐member task force of critical care pharmacists, physicians, and nurses participated in a Recommendation Development Phase and Consensus‐building Phase (using a Delphi method) to produce the final critical care practice advancement recommendations. Proposed recommendations of pragmatic medication management opportunities with an advanced scope of practice involving pharmacist prescriptive authority for initiating, modifying, or discontinuing drug therapy and medication monitoring were developed. Task force participants anonymously voted on each proposed recommendation using a five‐point Likert scale (1 = strongly agree, 2 = agree, 3 = neutral, 4 = disagree, and 5 = strongly disagree). Recommendations failing to achieve consensus (≥70% agreement on "strongly agree"/"agree" votes) were revised for subsequent voting. Task force response rates during the first and second voting rounds were 71% (n = 17) and 79% (n = 19), respectively. A total of 57 (93.4%) of the 61 proposed practice advancement recommendations achieved consensus of which 88.5% (n = 54) met consensus after the first round. Consensus recommendations involved the critical care pharmacist initiating (n = 15), modifying (n = 22), or discontinuing (n = 9) drug therapy, and ordering relevant laboratory values or tests to optimize drug therapy (n = 11). One recommendation failing consensus was not revised for additional voting given the impracticality of achieving agreement. Fifty‐seven of the proposed 61 recommendation statements (93%) achieved the consensus threshold after two rounds of voting by an interprofessional expert panel. These recommendations provide a conceptual framework for promoting novel critical care pharmacist prescriptive authority over specific aspects of direct patient care. Implementation challenges and barriers, further described in this paper, must be explored at the institutional level for acceptance. [ABSTRACT FROM AUTHOR]

Heart and lung transplant recipients require care provided by clinicians from multiple different specialties, each contributing unique expertise and perspective. The period the patient spends in the intensive care unit is one of the most critical times in the perioperative trajectory. Various organizational models of intensive care exist, including those led by intensivists, surgeons, transplant cardiologists, and pulmonologists. Coordinating timely efficient intensive care is an essential and logistically difficult goal. The present work product of the American Society of Transplantation's Thoracic and Critical Care Community of Practice, Critical Care Task Force outlines operational guidelines and principles that may be applied in different organizational models to optimize the delivery of intensive care for the cardiothoracic organ recipient. [ABSTRACT FROM AUTHOR]

Objective: Airborne spread of the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) remains a significant risk for healthcare workers. Understanding transmission of SARS‐CoV‐2 in the hospital could help minimize nosocomial infection. The objective of this pilot study was to measure aerosolization of SARS‐CoV‐2 in the hospital rooms of COVID‐19 patients. Methods: Two air samplers (Inspirotec) were placed 1 and 4 m away from adults with SARS‐CoV‐2 infection hospitalized at an urban, academic tertiary care center from June to October 2020. Airborne SARS‐CoV‐2 concentration was measured by quantitative reverse transcription polymerase chain reaction and analyzed by clinical parameters and patient demographics. Results: Thirteen patients with COVID‐19 (eight females [61.5%], median age: 57 years old, range 25–82) presented with shortness of breath (100%), cough (38.5%) and fever (15.4%). Respiratory therapy during air sampling varied: mechanical ventilation via endotracheal tube (n = 3), high flow nasal cannula (n = 4), nasal cannula (n = 4), respiratory helmet (n = 1), and room air (n = 1). SARS‐CoV‐2 RNA was identified in rooms of three out of three intubated patients compared with one out of 10 of the non‐intubated patients (p =.014). Airborne SARS‐CoV‐2 tended to decrease with distance (1 vs. 4 m) in rooms of intubated patients. Conclusions: Hospital rooms of intubated patients had higher levels of aerosolized SARS‐CoV‐2, consistent with increased aerosolization of virus in patients with severe disease or treatment with positive pressure ventilation through an endotracheal tube. While preliminary, these data have safety implications for health care workers and design of protective measures in the hospital. Level of Evidence: 2 [ABSTRACT FROM AUTHOR]

Background: Gastrointestinal (GI) motility disorders affect millions of people worldwide, yet they remain poorly treated in part due to insufficient knowledge of the molecular networks controlling GI motility. Interstitial cells of Cajal (ICC) are critical GI pacemaker cells, and abnormalities in ICC are implicated in GI motility disorders. Two cell surface proteins, KIT and ANO1, are used for identifying ICC. However, difficulties accessing human tissue and the low frequency of ICC in GI tissues have meant human ICC are insufficiently characterized. Here, a range of characterization assays including single‐cell RNA sequencing (scRNA‐seq) was performed using KIT+CD45−CD11B− primary human gastric ICC to better understand networks controlling human ICC biology. Methods: Excess sleeve gastrectomy tissues were dissected; ICC were analyzed by immunofluorescence, fluorescence‐activated cell sorting (FACSorting), real‐time PCR, mass spectrometry, and scRNA‐seq. Key Results: Immunofluorescence identified ANO1+/KIT+ cells throughout the gastric muscle. Compared to the FACSorted negative cells, PCR showed the KIT+CD45−CD11B− ICC were enriched 28‐fold in ANO1 expression (p < 0.01). scRNA‐seq analysis of the KIT−CD45+CD11B+ and KIT+CD45−CD11B− ICC revealed separate clusters of immune cells and ICC (respectively); cells in the ICC cluster expressed critical GI motility genes (eg, CAV1 and PRKG1). The scRNA‐seq data for these two cell clusters predicted protein interaction networks consistent with immune cell and ICC biology, respectively. Conclusions & Inferences: The single‐cell transcriptome of purified KIT+CD45−CD11B− human gastric ICC presented here provides new molecular insights and hypotheses into evolving models of GI motility. This knowledge will provide an improved framework to investigate targeted therapies for GI motility disorders. [ABSTRACT FROM AUTHOR]

Critical care, heart disease, lung disease Keywords: critical care; heart disease; lung disease EN critical care heart disease lung disease 1 3 3 04/13/23 20230401 NES 230401 The ability to promptly recognize and manage complications following cardiac surgery is closely associated with operative mortality,[1] and there has been increasing interest in the impact of intensive care unit (ICU) staffing models on post-operative care.[[2], [4]] Thoracic transplant recipients have particularly complex peri-operative care needs necessitating a multidisciplinary approach, yet there is limited information on existing ICU structure and staffing models for these patients in current practice. In total, 17 (60.7%) respondents were critical care board certified, and 6 (50%) anesthesiologists were dual trained in critical care and cardiac anesthesia. [Extracted from the article]

Life‐history studies are often conducted in a laboratory environment where it is easy to assay individual animals. However, factors such as temperature, photoperiod, and nutrition vary greatly between laboratory and field environments, making it difficult to compare results. Consequently, there is a need to study individual life histories in the field, but this is currently difficult in systems such as Daphnia where it is not possible to mark and track individual animals. Here, we present a proof of principle study showing that field cages are a reliable method for collecting individual‐level life‐history data in Daphnia magna. As a first step, we compared the life history of paired animals reared outside and inside cages to test the hypothesis that cages allow free flow of algal food resources. We then used a seminatural mesocosm setting to compare the performance of individual field cages versus glass jars refilled with mesocosm water each day. We found that cages did not inhibit food flow and that differences in life histories between three clones detected in the jar assays were also detectable using the much less labor‐intensive field cages. We conclude that field cages are a feasible approach for collecting individual‐level life‐history data in systems such as Daphnia where individual animals cannot be marked and tracked. [ABSTRACT FROM AUTHOR]

Facultative, heritable endosymbionts are found at intermediate prevalence within most insect species, playing frequent roles in their hosts' defence against environmental pressures. Focusing on Hamiltonella defensa, a common bacterial endosymbiont of aphids, we tested the hypothesis that such pressures impose seasonal balancing selection, shaping a widespread infection polymorphism. In our studied pea aphid (Acyrthosiphon pisum) population, Hamiltonella frequencies ranged from 23.2% to 68.1% across a six‐month longitudinal survey. Rapid spikes and declines were often consistent across fields, and we estimated that selection coefficients for Hamiltonella‐infected aphids changed sign within this field season. Prior laboratory research suggested antiparasitoid defence as the major Hamiltonella benefit, and costs under parasitoid absence. While a prior field study suggested these forces can sometimes act as counter‐weights in a regime of seasonal balancing selection, our present survey showed no significant relationship between parasitoid wasps and Hamiltonella prevalence. Field cage experiments provided some explanation: parasitoids drove modest ~10% boosts to Hamiltonella frequencies that would be hard to detect under less controlled conditions. They also showed that Hamiltonella was not always costly under parasitoid exclusion, contradicting another prediction. Instead, our longitudinal survey – and two overwintering studies – showed temperature to be the strongest predictor of Hamiltonella prevalence. Matching some prior lab discoveries, this suggested that thermally sensitive costs and benefits, unrelated to parasitism, can shape Hamiltonella dynamics. These results add to a growing body of evidence for rapid, seasonal adaptation in multivoltine organisms, suggesting that such adaptation can be mediated through the diverse impacts of heritable bacterial endosymbionts. [ABSTRACT FROM AUTHOR]

Rewilding or wilding is a popularised means for enhancing the conservation value of marginal land. In the British uplands, it will involve a reduction, or complete removal, of livestock grazing (sheep), based on the belief that grazing has reduced plant species diversity, the 'Wet Desert' hypothesis. The hope is that if livestock is removed, diversity will recover. If true, we hypothesise that the species extirpated/reduced by grazing and then recover on its removal would more nutritious compared to those that persisted. We test this hypothesis at Moor House National Nature Reserve (North‐Pennines), where seven sets of paired plots were established between 1953 and 1967 to compare ungrazed/sheep‐grazed vegetation. Within these plot‐pairs, we compared leaf properties of seven focal species that occurred only, or were present in much greater abundance, in the absence of grazing to those of 10 common species that were common in both grazed and ungrazed vegetation. Each sample was analysed for macro‐nutrients, micro‐nutrients, digestibility, palatability and decomposability. We ranked the species with respect to 22 variables based on effect size derived from Generalised Linear Modelling (GLM) and compared species using a Principal Components Analysis. We also assessed changes in abundance of the focal species through time using GLMs. Our results support the 'Wet Desert' hypothesis, that is, that long‐term sheep grazing has selectively removed/reduced species like our focal ones and on recovery, they were more nutritious (macro‐nutrients, some micro‐nutrients) palatable, digestible and decomposable than common species. Measured changes in abundance of the focal species suggest that their recovery will take 10–20 years in blanket bog and 60 years in high‐altitude grasslands. Collectively, these results suggest that sheep grazing has brought about biotic homogenization, and its removal in (re)wilding schemes will reverse this process eventually! The 'white woolly maggots' have eaten at least part of the heart out of the highlands/uplands, and it will take some time for recovery. [ABSTRACT FROM AUTHOR]

Warming and thawing in the Arctic are promoting biogeochemical processing and hydrologic transport in carbon‐rich permafrost and soils that transfer carbon to surface waters or the atmosphere. Hydrologic and biogeochemical impacts of thawing are challenging to predict with sparse information on arctic soil hydraulic and thermal properties. We developed empirical and statistical models of soil properties for three main strata in the shallow, seasonally thawed soils above permafrost in a study area of ~7,500 km2 in Alaska. The models show that soil vertical stratification and hydraulic properties are predictable based on vegetation cover and slope. We also show that the distinct hydraulic and thermal properties of each soil stratum can be predicted solely from bulk density. These findings fill the gap for a sparsely mapped region of the Arctic and enable regional interpolation of soil properties critical for determining future hydrologic responses and the fate of carbon in thawing permafrost. Plain Language Summary: Arctic permafrost holds about as much carbon as currently present in the atmosphere. Rapid warming in the Arctic has raised concerns that this stored carbon could thaw and get released into the atmosphere, which would substantially amplify global warming. The rate of this carbon release to the atmosphere depends on the rate of environmental processes such as microbial respiration and heat and groundwater flow. The soil properties controlling these processes are currently unknown across most of the Arctic, making predictions of the processes highly uncertain at larger scales. This study uses hundreds of measurements of soil properties across an area of land larger than Delaware to show that soil properties in the foothills of the Brooks Range in northern Alaska are predictable if the landscape slope, dominant vegetation type, and local topography are known. This study provides a base for calculating transport processes related to soil carbon in the Arctic. Key Points: Thermal and hydraulic properties of 265 permafrost soil samples from across the Arctic foothills of Alaska were measuredDifferent soil strata (acrotelm, catotelm, and mineral soil) have consistent properties and thickness over hundreds of kilometersThe soil properties are strongly related to vegetation and surface slope and can be independently predicted from soil bulk density [ABSTRACT FROM AUTHOR]

Monoclonal antibodies (mAbs) are biopharmaceuticals produced by mammalian cell lines in bioreactors at a variety of scales. Cell engineering, media optimization, process monitoring, and control strategies for in vitro production have become crucial subjects to meet increasing demand for these high value pharmaceuticals. Raman Spectroscopy has gained great attention in the pharmaceutical industry for process monitoring and control to maintain quality assurance. For the first time, this article demonstrated the possibility of subclass independent quantitative mAb prediction by Raman spectroscopy in real time. The developed model estimated the concentrations of different mAb isotypes with average prediction errors of 0.2 (g/L) over the course of cell culture. In situ Raman spectroscopy combined with chemometric methods showed to be a useful predictive tool for monitoring of real time mAb concentrations in a permeate stream without sample removal. Raman spectroscopy can, therefore, be considered as a reliable process analytical technology tool for process monitor, control, and intensification of downstream continuous manufacturing. The presented results provide useful information for pharmaceutical industries to choose the most appropriate spectroscopic technology for their continuous processes. [ABSTRACT FROM AUTHOR]

Aims: Some patients with upper gastrointestinal symptoms have rapid gastric emptying (GE). We aimed to compare patients with normal and rapid GE and to identify phenotypes among patients with rapid GE. Methods: Among 2798 patients who underwent GE scintigraphy, we compared patients with normal and rapid GE and separately, patients with rapid GE at 1 hour (GE1), 2 hours (GE2), or both (GE12). Results: In 2798 patients, GE was normal (74%), delayed (18%), or rapid (8%). Among 211 patients with rapid GE, patterns were rapid GE1 (48%), 2 hours (17%), or 1 and 2 hours (35%); 42 (20%) had diseases that explain rapid GE. A combination of upper and lower gastrointestinal symptoms (54%) was more common that isolated upper (17%) or lower (28%) gastrointestinal symptoms (P <.001). Constipation was more prevalent in patients with rapid GE 2 (72%) than rapid GE 1 (47%) or rapid GE12 hours (67%) (P <.05). Among 179 diabetes mellitus (DM) patients, 15% had rapid GE, which was not associated with the DM phenotype. By multivariable analysis, insulin therapy (odds ratio [OR], 0.36; 95% confidence interval [CI], 0.15‐0.88), and weight loss (OR, 0.10; 95% CI, 0.01‐0.78) were associated with a lower risk of rapid than normal GE in DM. Conclusions: Eight percent of patients undergoing scintigraphy had rapid GE, which is most frequently associated with upper and lower gastrointestinal symptoms; constipation is common. Insulin therapy and weight loss were associated with a lower risk of rapid than normal GE in DM patients. [ABSTRACT FROM AUTHOR]

Background and Purpose: SISCOM and STATISCOM were clinically proved to be effective for ictal/inter-ictal single-photon emission computed tomography (SPECT) analysis coregistered with magnetic resonance imaging (MRI) for seizure localization. Recently, a software package also became available for this analysis. This study aimed to investigate and compare the performance of these analysis methods for seizure localization.Methods: A total of 378 patients who underwent 99m Tc-ethyl cysteinate dimer (ECD) SPECT scans were retrospectively reviewed and 28 remained after applying exclusion criteria. Their SPECT and MRI images were analyzed with SISCOM (with z-score of 1.5 and 2), STATISCOM, and MIMneuro, resulting in a total of 112 image data sets. Two experienced radiologists participated in the blind review process using a custom tool and they can mark up to two hyper- and/or hypoperfusion regions. Their review results were analyzed using the Jackknife Free Response Receiver-Operating Characteristics (JAFROC) test and the JAFROC figure-of-merit (FoM) was reported for each method. The interobserver agreement was also assessed using Cohen's kappa test.Results: Based on the readers' two choices, averaged FoM was 85.7%, 83.9%, 66.1%, and 51.8% for STATISCOM, MIMneuro, SISCOM (z-score = 2), and SISCOM (z-score = 1.5), respectively. The average confidence rating was 2.5, 2.3, 1.6, and 1.1 for STATISCOM, MIMneuro, SISCOM (z-score = 2), and SISCOM (z-score = 1.5), respectively. For interobserver agreement, kappa was .742 for STATISCOM, .816 for MIMneuro, .517 for SISCOM (z-score = 2), and .441 for SISCOM (z-score = 1.5; all P < .001).Conclusion: Our study demonstrated that STATISCOM showed the best performance for seizure localization, which was closely followed by MIMneuro. In addition, MIMneuro was not inferior to SISCOM with either z-score. [ABSTRACT FROM AUTHOR]

The external drivers and internal controls of groundwater flow in the thawed "active layer" above permafrost are poorly constrained because they are dynamic and spatially variable. Understanding these controls is critical because groundwater can supply solutes such as dissolved organic matter to surface water bodies. We calculated steady‐state three‐dimensional suprapermafrost groundwater flow through the active layer using measurements of aquifer geometry, saturated thickness, and hydraulic properties collected from two major landscape types over time within a first‐order Arctic watershed. The depth position and thickness of the saturated zone is the dominant control of groundwater flow variability between sites and during different times of year. The effect of water table depth on groundwater flow dwarfs the effect of thaw depth. In landscapes with low land‐surface slopes (2–4%), a combination of higher water tables and thicker, permeable peat deposits cause relatively constant groundwater flows between the early and late thawed seasons. Landscapes with larger land‐surface slopes (4–10%) have both deeper water tables and thinner peat deposits; here the commonly observed permeability decrease with depth is more pronounced than in flatter areas, and groundwater flows decrease significantly between early and late summer as the water table drops. Groundwater flows are also affected by microtopographic features that retain groundwater that could otherwise be released as the active layer deepens. The dominant sources of groundwater, and thus dissolved organic matter, are likely wet, flatter regions with thick organic layers. This finding informs fluid flow and solute transport dynamics for the present and future Arctic. Plain Language Summary: Groundwater flow in permafrost watersheds is potentially a key component of global carbon budgets because permafrost soil stores vast amounts of carbon that could be mobilized due to a warming climate and the corresponding increase in soil thaw. In addition to carrying carbon, groundwater can supply important nutrients and solutes to surface waters. However, we do not yet understand the factors that control groundwater flow in soils above permafrost because saturation changes rapidly and continuously, and soil hydraulic properties are largely unknown. We created measurement‐informed calculations of groundwater flow from areas of permafrost with different characteristics and found that soil types, which vary based on the slope of the land surface, are the most important control. Near‐surface soils were identical in hillslopes and valleys, whereas deeper soils in hillslopes allowed for less groundwater flow than in valleys. In early summer, when only the near‐surface soils were thawed, groundwater flows in the hillslopes and valley were similar. In late summer, when the deeper soil was thawed, groundwater flow in the valley remained high, but flow in the hillslope was negligible. Our observations also showed that small mounds on the land surface caused groundwater to be trapped behind underground ice dams. Key Points: Detailed measurements of hydraulic head, hydraulic conductivity, and saturated thicknesses in active layers were made over time and spaceThree main soil layers consistently comprise the stratigraphy of the active layer across the studied Arctic watershedGroundwater flow depends most on the depth of the water table and the subsurface stratigraphy, which varies based on landscape type [ABSTRACT FROM AUTHOR]

Endothermic animals do not always have a single adaptive internal temperature; some species exhibit plastic homeostasis, adaptively allowing body temperature to drop when thermoregulatory costs are high. Like large‐bodied endotherms, some animal societies exhibit collective thermal homeostasis. We tested for plasticity of thermoregulation in the self‐assembled temporary nests (bivouacs) of army ants. We measured core bivouac temperatures under a range of environmental conditions and at different colony developmental (larval vs pupal brood) stages. Contrary to previous assertions, bivouacs were not perfect thermoregulators in all developmental stages. Instead, bivouacs functioned as superorganismal facultative endotherms, using a combination of site choice and context‐dependent metabolic heating to adjust core temperatures across an elevational cline in ambient temperature. When ambient temperature was low, the magnitude of metabolic heating was dependent on colony developmental stage: pupal bivouacs were warmer than larval bivouacs. At cooler high elevations, bivouacs functioned like some endothermic animals that intermittently lower their body temperatures to conserve energy. Bivouacs potentially conserved energy by investing less metabolic heating in larval brood because the high costs of impaired worker development may require more stringent thermoregulation of pupae. Our data also suggest that site choice played an important role in bivouac cooling under high ambient temperatures at low elevations. Climate warming may expand upper elevational range limits of Eciton burchellii parvispinum, while reducing the availability of cool and moist bivouac sites at lower elevations, potentially leading to future low‐elevation range contraction. [ABSTRACT FROM AUTHOR]

Abstract: Groundwater flow regimes in the seasonally thawed soils in areas of continuous permafrost are relatively unknown despite their potential role in delivering water, carbon, and nutrients to streams. Using numerical groundwater flow models informed by observations from a headwater catchment in arctic Alaska, United States, we identify several mechanisms that result in substantial surface‐subsurface water exchanges across the land surface during downslope transport and create a primary control on dissolved organic carbon loading to streams and rivers. The models indicate that surface water flowing downslope has a substantial groundwater component due to rapid surface‐subsurface exchanges across a range of hydrologic states, from unsaturated to flooded. Field‐based measurements corroborate the high groundwater contributions, and river dissolved organic carbon concentrations are similar to that of groundwater across large discharge ranges. The persistence of these groundwater contributions in arctic watersheds will influence carbon export to rivers as thaw depth increases in a warmer climate. [ABSTRACT FROM AUTHOR]

Abstract: Animal‐associated microbiomes are often comprised of structured, multispecies communities, with particular microbes showing trends of co‐occurrence or exclusion. Such structure suggests variable community stability, or variable costs and benefits—possibilities with implications for symbiont‐driven host adaptation. In this study, we performed systematic screening for maternally transmitted, facultative endosymbionts of the pea aphid, Acyrthosiphon pisum. Sampling across six locales, with up to 5 years of collection in each, netted significant and consistent trends of community structure. Co‐infections between Serratia symbiotica and Rickettsiella viridis were more common than expected, while Rickettsia and X‐type symbionts colonized aphids with Hamiltonella defensa more often than expected. Spiroplasma co‐infected with other endosymbionts quite rarely, showing tendencies to colonize as a single species monoculture. Field estimates of maternal transmission rates help to explain our findings: while Serratia and Rickettsiella improved each other's transmission, Spiroplasma reduced transmission rates of co‐infecting endosymbionts. In summary, our findings show that North American pea aphids harbour recurring combinations of facultative endosymbionts. Common symbiont partners play distinct roles in pea aphid biology, suggesting the creation of “generalist” aphids receiving symbiont‐based defence against multiple ecological stressors. Multimodal selection, at the host level, may thus partially explain our results. But more conclusively, our findings show that within‐host microbe interactions, and their resulting impacts on transmission rates, are an important determinant of community structure. Widespread distributions of heritable symbionts across plants and invertebrates hint at the far‐reaching implications for these findings, and our work further shows the benefits of symbiosis research within a natural context. [ABSTRACT FROM AUTHOR]

Ectotherms frequently thermoregulate behaviorally to improve physiological processes such as digestion and growth, but basking and other thermoregulatory activities can also increase predation risk. Organismal and environmental characteristics can, in some species, influence predation risk associated with thermoregulation and thereby relax or tighten constraints on thermoregulatory behavior, physiological performance, and, ultimately, life history traits. Providing one of the first such investigations in turtles, we examine whether behavior and thermal environment modulate a thermoregulation-predation risk trade-off in juvenile gopher tortoises ( Gopherus polyphemus). Young gopher tortoises experience very high predation pressure, and their declining species faces many challenges, including human-induced increased shading of its environment. We hypothesized that in response to simulated predator approach, basking hatchling and juvenile tortoises would: (i) hide inside burrows; (ii) hide for shorter durations in cooler burrows presumably due to greater constraints on physiological performance; and (iii) spend greater time at the surface following disturbance in cool environments because individuals would need to bask more to maintain preferred body temperatures. Basking tortoises always hid inside burrows when approached and exhibited very long flight initiation distances ( [ABSTRACT FROM AUTHOR]

Purpose The purpose of this study was to perform a pilot evaluation of an integrated molecular breast imaging/ultrasound ( MBI/ US) system designed to enable, in real-time, the registration of US to MBI and diagnostic evaluation of breast lesions detected on MBI. Methods The MBI/ US system was constructed by modifying an existing dual-head cadmium zinc telluride ( CZT)-based MBI gamma camera. The upper MBI detector head was replaced with a mesh panel, which allowed an ultrasound probe to access the breast. An optical tracking system was used to monitor the location of the ultrasound transducer, referenced to the MBI detector. The lesion depth at which ultrasound was targeted was estimated from analysis of previously acquired dual-head MBI datasets. A software tool was developed to project the US field of view onto the current MBI image. Correlation of lesion location between both modalities with real-time MBI/ US scanning was confirmed in a breast phantom model and assessed in 12 patients with a breast lesion detected on MBI. Results Combined MBI/ US scanning allowed for registration of lesions detected on US and MBI as validated in phantom experiments. In patient studies, successful registration was achieved in 8 of 12 (67%) patients, with complete registration achieved in seven and partial registration achieved in one patient. In 4 of 12 (37%) patients, lesion registration was not achieved, partially attributed to uncertainty in lesion depth estimates from MBI. Conclusion The MBI/ US system enabled successful registration of US to MBI in over half of patients studied in this pilot evaluation. Future studies are needed to determine if real-time, registered US imaging of MBI-detected lesions may obviate the need to proceed to more expensive procedures such as contrast-enhanced breast MRI for diagnostic workup or biopsy of MBI findings. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 72‐year‐old woman with a history of left‐sided invasive mammary carcinoma and detection of multifocal breast malignancy. Topics discussed a negative Positron-emission tomography (PET) scan with F‐18 FDG; mentions the molecular breast imaging (MBI) study, tomosynthesis that revealed three irregular spiculated masses in lower inner left breast and a subtle focal asymmetry in the superior breast; and mentions the utility of db‐PET in detecting occult disease.

This paper provides spatial estimates of potentially available biomass for bioenergy in Australia in 2010, 2030 and 2050 (under clearly stated assumptions) for the following biomass sources: crop stubble, native grasses, pulpwood and residues (created either during forest harvesting or wood processing) from plantations and native forests, bagasse, organic municipal solid waste and new short-rotation tree crops. For each biomass type, we estimated annual potential availability at the finest scale possible with readily accessible data, and then aggregated to make estimates for each of 60 Statistical Divisions (administrative areas) across Australia. The potentially available lignocellulosic biomass is estimated at approximately 80 Mt per year, with the major contributors of crop stubble (27.7 Mt per year), grasses (19.7 Mt per year) and forest plantations (10.9 Mt per year). Over the next 20-40 years, total potentially available biomass could increase to 100-115 Mt per year, with new plantings of short-rotation trees being the major source of the increase (14.7 Mt per year by 2030 and 29.3 Mt per year by 2050). We exclude oilseeds, algae and 'regrowth', that is woody vegetation naturally regenerating on previously cleared land, which may be important in several regions of Australia ( Australian Forestry 77, 2014, 1; Global Change Biology Bioenergy 7, 2015, 497). We briefly discuss some of the challenges to providing a reliable and sustainable supply of the large amounts of biomass required to build a bioenergy industry of significant scale. More detailed regional analyses, including of the costs of delivered biomass, logistics and economics of harvest, transport and storage, competing markets for biomass and a full assessment of the sustainability of production are needed to underpin investment in specific conversion facilities (e.g. Opportunities for forest bioenergy: An assessment of the environmental and economic opportunities and constraints associated with bioenergy production from biomass resources in two prospective regions of Australia, 2011a). [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to compare the system performance characteristics and lesion detection capability of two molecular breast imaging (MBI) systems: a multicrystal sodium iodide (NaI)-based single-head system and a cadmium zinc telluride (CZT)-based dual-head system at low administered doses (150–300 MBq) of Tc-99m sestamibi. Methods: System performance characteristics including count sensitivity, uniformity, energy resolution, and spatial resolution were measured using standard NEMA methods, or a modified version thereof in cases where the standard NEMA protocol could not be applied. A contrast-detail phantom with 48 lesions at varying depths from the collimator surface was used to assess lesion contrast-to-noise-ratio (CNR) using background count densities comparable to those observed in patient studies performed with administered doses of 150 MBq Tc-99m sestamibi. Lesions with CNR >3 were deemed to be detectable. Thirty patients undergoing MBI examinations with administered doses of 150–300 MBq were scanned for an additional view on the pixelated NaI system. CNR was calculated for lesions observed on patient images. Background count densities of patient images were measured and compared between the two systems. Results: Over the central field of view, integral and differential uniformity were 6.1% and 4.2%, respectively, for the pixelated NaI system, and 3.8% and 2.7%, respectively, for the CZT system. Count sensitivity was 10.8 kcts/min/MBq for the NaI system and 32.9 kcts/min/MBq for the CZT system. Energy resolution was 13.5% on the pixelated NaI system and 4.5% on the CZT system. Spatial resolution (full-width at half-maximum) for the pixelated NaI detector was 4.2 mm at a distance of 1.2 cm from the collimator and 5.2 mm at 3.1 cm. Spatial resolution of a single CZT detector was 2.9 mm at a distance of 1.2 cm from the collimator and 4.7 mm at 3.1 cm. Effective spatial resolution obtained with dual-head CZT was below 4.7 mm throughout a simulated breast thickness of 6 cm. From contrast-detail phantom images of lesions at distances of 1.5–4.5 cm from the collimator face, the CZT system detected 124 of 144 (86%) of lesions compared to 97 of 144 (67%) with the NaI system. In patient studies, from comparison of the same view with both systems, a total of 7 breast lesions were identified on CZT system in seven patients, and 4 of 7 (57%) were detected on NaI system. Patient image background count densities on the CZT system were on average 3.4 times higher than those on the NaI system. Conclusions: The CZT system demonstrated better uniformity, count sensitivity, spatial resolution, energy resolution, and lesion detection in phantom and patient studies compared to the NaI system. At administered doses of 150–300 MBq Tc-99m sestamibi, patient results obtained with CZT systems may not be directly translatable to NaI systems. [ABSTRACT FROM AUTHOR]

Aim An Australian study of older, community-dwelling women found that 80% would rather be dead than experience loss of independence and nursing home admission after a bad hip fracture. We re-examined this issue using a conjoint analysis approach. Methods We asked older hospital patients with a history of falls, fracture or osteoporosis to imagine they had a hip fracture resulting in significant residual disability. Subjects were asked to rank in order of preference an orthogonal array of nine out of 36 potential outcome scenarios reporting risk of falls, life expectancy, discharge home with support or to a nursing home and family agreement or disagreement with discharge location. Results Of 192 patients satisfying inclusion criteria, 183 agreed to participate and 97 completed the study. Those who failed to complete the study were older and had lower Mini- Mental State Examination scores than those who completed the study. For the group as a whole, averaged importance scores were: discharge residence 31.3%, length of life 27%, fall risk 26.4% and family preference 15.5%. On average, subjects would be willing to sacrifice approximately 9 months of life in order to return home rather than go to a nursing home. Conclusions In the present study, older people at high risk for fracture judged that after a bad hip fracture their main priority would be to remain at home. Geriatr Gerontol Int 2015; 15: 1165-1170. [ABSTRACT FROM AUTHOR]

The airline industry has a strong interest in developing sustainable aviation fuels, in order to reduce their exposure to increasing oil prices and cost liability for greenhouse gas emissions. The feasibility and cost of producing sustainable biomass-based jet fuels at a sufficient scale to materially address these issues is an enormous challenge. This paper builds directly on the biophysical study by H.T. Murphy, D.A. O'Connell, R.J. Raison, A.C. Warden, T.H. Booth, A. Herr, A.L. Braid, D.F. Crawford, J.A. Hayward, T. Javonovic, J.G. McIvor, M.H. O'Connor, M.L. Poole, D. Prestwidge, N. Raisbeck-Brown & L. Rye, In review, which examined a 25 year scale-up strategy to produce 5% of projected jet fuel demand in Australia in 2020 (470 mL) in the Fitzroy region of Queensland, Australia. The strategy was based on the use of a mixed ligno-cellulosic biomass feedstock and assumed, for the sake of exploring and quantifying the scenario, a simplified two-step conversion process - conversion of biomass to crude bio-oil within the region, and upgrade to jet fuel at a central Brisbane facility. This paper provides details on the costs of production in this scenario, focusing on two different strategies for biomass utilization, and two types of novel small-medium scale conversion technologies. The cost analyses have taken into account technology learning curves, different economies of scale and key cost sensitivities. The cost of biomass-based jet fuels is estimated to be between 0.70 and 1.90 $ L−1 when the efficiency of conversion of biomass to biocrude and subsequently to aviation fuel is varied by ±10% of published values, with an average value of 1.10 $ L−1. This is within the range of the projected 2035 conventional jet fuel price of 1.50 $ L−1. Therefore, biomass-based jet fuel has the potential to contribute to supply of Australia's jet fuel needs in the future. [ABSTRACT FROM AUTHOR]

The microbiome can significantly impact host phenotypes and serve as an additional source of heritable genetic variation. While patterns across eukaryotes are consistent with a role for symbiotic microbes in host macroevolution, few studies have examined symbiont-driven host evolution or the ecological implications of a dynamic microbiome across temporal, spatial or ecological scales. The pea aphid, Acyrthosiphon pisum, and its eight heritable bacterial endosymbionts have served as a model for studies on symbiosis and its potential contributions to host ecology and evolution. But we know little about the natural dynamics or ecological impacts of the heritable microbiome of this cosmopolitan insect pest. Here we report seasonal shifts in the frequencies of heritable defensive bacteria from natural pea aphid populations across two host races and geographic regions. Microbiome dynamics were consistent with symbiont responses to host-level selection and findings from one population suggested symbiont-driven adaptation to seasonally changing parasitoid pressures. Conversely, symbiont levels were negatively correlated with enemy-driven mortality when measured across host races, suggesting important ecological impacts of host race microbiome divergence. Rapid drops in symbiont frequencies following seasonal peaks suggest microbiome instability in several populations, with potentially large costs of 'superinfection' under certain environmental conditions. In summary, the realization of several laboratory-derived, a priori expectations suggests important natural impacts of defensive symbionts in host-enemy eco-evolutionary feedbacks. Yet negative findings and unanticipated correlations suggest complexities within this system may limit or obscure symbiont-driven contemporary evolution, a finding of broad significance given the widespread nature of defensive microbes across plants and animals. [ABSTRACT FROM AUTHOR]

Current USFDA and EMA guidance for drug transporter interactions is dependent on IC50 measurements as these are utilized in determining whether a clinical interaction study is warranted. It is therefore important not only to standardize transport inhibition assay systems but also to develop uniform statistical criteria with associated probability statements for generation of robust IC50 values, which can be easily adopted across the industry. The current work provides a quantitative examination of critical factors affecting the quality of IC50 fits for P-gp inhibition through simulations of perfect data with randomly added error as commonly observed in the large data set collected by the P-gp IC50 initiative. The types of errors simulated were (1) variability in replicate measures of transport activity; (2) transformations of error-contaminated transport activity data prior to IC50 fitting (such as performed when determining an IC50 for inhibition of P-gp based on efflux ratio); and (3) the lack of well defined 'no inhibition' and 'complete inhibition' plateaus. The effect of the algorithm used in fitting the inhibition curve (e.g., two or three parameter fits) was also investigated. These simulations provide strong quantitative support for the recommendations provided in Bentz et al. () for the determination of IC50 values for P-gp and demonstrate the adverse effect of data transformation prior to fitting. Furthermore, the simulations validate uniform statistical criteria for robust IC50 fits in general, which can be easily implemented across the industry. A calibration of the t-statistic is provided through calculation of confidence intervals associated with the t-statistic. [ABSTRACT FROM AUTHOR]

ABSTRACT Human embryonic stem cells (hESCs) can be differentiated into multiple cell types with great therapeutic potential. However, optimizing the often multi-week cultures to obtain sufficient differentiated cell yields has been in part limited by the high variability of even parallel hESC differentiation cultures. We describe the isolation and features of a subline of CA1 hESCs (CA1S) that display a very high 25% cloning efficiency while retaining many properties of the parental hESCs, including being karyotypically normal and their ability to generate teratomas containing all three germ layers. Although more detailed analysis revealed that CA1S cells have a 3.8 Mb genomic duplication on chromosome 20, they remain highly useful. In particular, CA1S cells are readily expanded at high yields in culture and possess greatly reduced well-to-well variation even when seeded at 100 cells/well. Thus, 108 CA1S cells can be generated within one week from 106 cells to seed 106 wells. We determined that CA1S cells have the capacity to follow established in vitro differentiation protocols to pancreatic progenitors and subsequent hormone-positive cell types and used CA1S cells to explore definitive endoderm induction in a high performance screen ( Z-factor = 0.97). This system revealed that CA1S cells do not require WNT3A to efficiently form definitive endoderm, a finding that was confirmed with H1 hESCs, although H1 cells did show modest benefits of high WNT3A doses. Proliferative index measurements of CA1S cells were shown to rapidly reflect their differentiation status in a high throughput system. Though results obtained with CA1S cells will need to be confirmed using conventional hESC lines, these cells should ease the development of optimized hESC growth and differentiation protocols. In particular, they should limit the more arduous secondary screens using hESCs to a smaller number of variables and doses. Biotechnol. Bioeng. 2013;110: 2706-2716. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Approaches to imaging the breast with nuclear medicine and/or molecular imaging methods have been under investigation since the late 1980s when a technique called scintimammography was first introduced. This review charts the progress of nuclear imaging of the breast over the last 20 years, covering the development of newer techniques such as breast specific gamma imaging, molecular breast imaging, and positron emission mammography. Key issues critical to the adoption of these technologies in the clinical environment are discussed, including the current status of clinical studies, the efforts at reducing the radiation dose from procedures associated with these technologies, and the relevant radiopharmaceuticals that are available or under development. The necessary steps required to move these technologies from bench to bedside are also discussed. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the effect of short-term high fat feeding on the inflammatory response in polymicrobial sepsis. Male C57BL/6 mice at 6 weeks of age were randomized to a high-fat diet (HFD) (60% kcal fat) or control diet (CD) (16% kcal fat) for 3 weeks. After 3 weeks of feeding, sepsis was induced by cecal ligation and puncture (CLP) and animals were monitored for survival. In a separate experiment, after 3 weeks of feeding mice underwent CLP and were sacrificed at various time points thereafter. Tissue was collected for biochemical studies. Mice fed a HFD gained more weight and had a greater fat mass compared to CD-fed mice. Mice on a HFD had a lower probability of survival and more severe lung injury compared with CD-fed mice following sepsis. Myeloperoxidase (MPO) activity, an indicator of neutrophil infiltration, was increased in the lung and liver after CLP in HFD-fed mice compared with CD (P < 0.05). The plasma cytokines tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 were increased in both groups after CLP, however, TNF-α and IL-6 levels were lower in HFD mice at 3 h after CLP compared with CD and consistent with lung, but not liver, messenger RNA (mRNA) expression. Leptin levels were higher in HFD-fed mice at 18 h after sepsis compared to baseline levels (P < 0.05). Polymicrobial sepsis increased hepatic nuclear factor-κB (NF-κB) activation in HFD-fed mice after CLP vs. CD-fed mice. Short duration high fat feeding increases mortality and organ injury following polymicrobial sepsis. These effects correspond to changes in NF-κB. [ABSTRACT FROM AUTHOR]

Symbiotic bacteria often help their hosts acquire nutrients from their diet, showing trends of co-evolution and independent acquisition by hosts from the same trophic levels. While these trends hint at important roles for biotic factors, the effects of the abiotic environment on symbiotic community composition remain comparably understudied. In this investigation, we examined the influence of abiotic and biotic factors on the gut bacterial communities of fish from different taxa, trophic levels and habitats. Phylogenetic and statistical analyses of 25 16S rRNA libraries revealed that salinity, trophic level and possibly host phylogeny shape the composition of fish gut bacteria. When analysed alongside bacterial communities from other environments, fish gut communities typically clustered with gut communities from mammals and insects. Similar consideration of individual phylotypes (vs. communities) revealed evolutionary ties between fish gut microbes and symbionts of animals, as many of the bacteria from the guts of herbivorous fish were closely related to those from mammals. Our results indicate that fish harbour more specialized gut communities than previously recognized. They also highlight a trend of convergent acquisition of similar bacterial communities by fish and mammals, raising the possibility that fish were the first to evolve symbioses resembling those found among extant gut fermenting mammals. [ABSTRACT FROM AUTHOR]

Purpose: Molecular breast imaging (MBI) is a nuclear medicine technology that uses dual-head cadmium zinc telluride (CZT) gamma cameras to image functional uptake of a radiotracer, Tc-99m sestamibi, in the breast. An important factor in adoption of MBI in the screening setting is reduction of the necessary administered dose of Tc-99m sestamibi from the typically used dose of 740 MBq to approximately 148 MBq, such that MBI's whole-body effective dose is comparable to that of screening mammography. Methods that increase MBI count sensitivity may allow a proportional reduction in the necessary administered dose. Our objective was to evaluate the impact of two count sensitivity improvement methods on image quality by evaluating count sensitivity, spatial resolution, and lesion contrast in phantom simulations. Methods: Two dual-head CZT-based MBI systems were studied: LumaGem and Discovery NM 750b. Two count sensitivity improvement methods were implemented: registered collimators optimized for dedicated breast imaging and widened energy acceptance window optimized for use with CZT. System sensitivity, spatial resolution, and tumor contrast-to-noise ratio (CNR) were measured comparing standard collimation and energy window setting [126-154 keV (+10%, -10%)] with optimal collimation and a wide energy window [110-154 keV (+10%, -21%)]. Results: Compared to the standard collimator designs and energy windows for these two systems, use of registered optimized collimation and wide energy window increased system sensitivity by a factor of 2.8-3.6. Spatial resolution decreased slightly for both systems with new collimation. At 3 cm from the collimator face, LumaGem's spatial resolution was 4.8 and 5.6 mm with standard and optimized collimation; Discovery NM 750b's spatial resolution was 4.4 and 4.6 mm with standard and optimized collimation, respectively. For both systems, at tumor depths of 1 and 3 cm, use of optimized collimation and wide energy window significantly improved CNR compared to standard settings for tumors 8.0 and 9.2 mm in diameter. At the closer depth of 1 cm, optimized collimation and wide energy window also significantly improved CNR for 5.9 mm tumors on Discovery NM 750b. Conclusions: Registered optimized collimation and wide energy window yield a substantial gain in count sensitivity and measurable gain in CNR, with some loss in spatial resolution compared to the standard collimator designs and energy windows used on these two systems. At low-count densities calculated to represent doses of 148 MBq, this tradeoff results in adequate count density and lesion contrast for detection of lesions ≥8 mm in the middle of a typical breast (3 cm deep) and lesions ≥6 mm close to the collimator (1 cm deep). [ABSTRACT FROM AUTHOR]

We provide a quantitative assessment of the prospects for current and future biomass feedstocks for bioenergy in Australia, and associated estimates of the greenhouse gas ( GHG) mitigation resulting from their use for production of biofuels or bioelectricity. National statistics were used to estimate current annual production from agricultural and forest production systems. Crop residues were estimated from grain production and harvest index. Wood production statistics and spatial modelling of forest growth were used to estimate quantities of pulpwood, in-forest residues, and wood processing residues. Possible new production systems for oil from algae and the oil-seed tree Pongamia pinnata, and of lignocellulosic biomass production from short-rotation coppiced eucalypt crops were also examined. The following constraints were applied to biomass production and use: avoiding clearing of native vegetation; minimizing impacts on domestic food security; retaining a portion of agricultural and forest residues to protect soil; and minimizing the impact on local processing industries by diverting only the export fraction of grains or pulpwood to bioenergy. We estimated that it would be physically possible to produce 9.6 GL yr−1 of first generation ethanol from current production systems, replacing 6.5 GL yr−1 of gasoline or 34% of current gasoline usage. Current production systems for waste oil, tallow and canola seed could produce 0.9 GL yr−1 of biodiesel, or 4% of current diesel usage. Cellulosic biomass from current agricultural and forestry production systems (including biomass from hardwood plantations maturing by 2030) could produce 9.5 GL yr−1 of ethanol, replacing 6.4 GL yr−1 of gasoline, or ca. 34% of current consumption. The same lignocellulosic sources could instead provide 35 TWh yr−1, or ca. 15% of current electricity production. New production systems using algae and P. pinnata could produce ca. 3.96 and 0.9 GL biodiesel yr−1, respectively. In combination, they could replace 4.2 GL yr−1 of fossil diesel, or 23% of current usage. Short-rotation coppiced eucalypt crops could provide 4.3 GL yr−1 of ethanol (2.9 GL yr−1 replacement, or 15% of current gasoline use) or 20.2 TWh yr−1 of electricity (9% of current generation). In total, first and second generation fuels from current and new production systems could mitigate 26 Mt CO2-e, which is 38% of road transport emissions and 5% of the national emissions. Second generation fuels from current and new production systems could mitigate 13 Mt CO2-e, which is 19% of road transport emissions and 2.4% of the national emissions lignocellulose from current and new production systems could mitigate 48 Mt CO2-e, which is 28% of electricity emissions and 9% of the national emissions. There are challenging sustainability issues to consider in the production of large amounts of feedstock for bioenergy in Australia. Bioenergy production can have either positive or negative impacts. Although only the export fraction of grains and sugar was used to estimate first generation biofuels so that domestic food security was not affected, it would have an impact on food supply elsewhere. Environmental impacts on soil, water and biodiversity can be significant because of the large land base involved, and the likely use of intensive harvest regimes. These require careful management. Social impacts could be significant if there were to be large-scale change in land use or management. In addition, although the economic considerations of feedstock production were not covered in this article, they will be the ultimate drivers of industry development. They are uncertain and are highly dependent on government policies (e.g. the price on carbon, GHG mitigation and renewable energy targets, mandates for renewable fuels), the price of fossil oil, and the scale of the industry. [ABSTRACT FROM AUTHOR]

Medical Education 2011: 45: 1251-1261 Objectives Professional status and working arrangements can inhibit doctors from acknowledging and seeking care for their own ill health. Research identifies that a culture of immunity to illness within the medical profession takes root during training. What happens when trainee doctors become unwell during their formative period of education and training? What support do they receive and how do they perceive that the experience of ill health affects their training trajectory? These research questions were developed by a multidisciplinary team of researchers and health professionals, who adopted a qualitative approach to investigate the experiences of personal illness among trainees in their Foundation Programme (FP) years. Methods Semi-structured interviews were conducted with eight FP trainees from the Severn Deanery in southwest England who had experienced significant illness. Interpretative phenomenological analysis was used to conduct and analyse the interviews, resulting in a comprehensive list of master themes. This paper reports an interpretative analysis of the themes of Support, Illness Experience, Crossing the Line, Medical Culture, Stigma and Disclosure. Results Ineffective communication within the medical education and employment system underpins many of the difficulties encountered by trainees who are unwell. Coping style plays a key role in predicting how trainees experience support during and after their illness, although this may be influenced by their particular diagnoses. The barriers to disclosure of their illnesses are discussed within the context of mobilising and maintaining support. Concern about the impact of missing training as a result of ill health appears to be significant in the transmitting of an ethos of invulnerability within the medical culture. Conclusions Suggestions to improve support procedures for trainees who are unwell include the provision of greater flexibility within the rotation system along with independent pastoral support. Promoting the importance of disclosing significant illness as early as possible might go some way towards challenging the culture of invulnerability to illness that prevails among doctors. [ABSTRACT FROM AUTHOR]

The A-minor interaction, formed between single-stranded adenosines and the minor groove of a receptor helix, is among the most common motifs found in rRNA. Among the A-minors found in 16S rRNA are a set of interactions between adenosines at positions 1433, 1434 and 1468 in helix 44 (h44) and their receptors in the nucleotide 320-340 region of helix 13 (h13). These interactions have been implicated in the maintenance of translational accuracy, because base substitutions at the adjacent C1469 increase miscoding errors. We have tested their functional significance through mutagenesis of h13 and h44. Mutations at the h44 A residues, or the A-minor receptors in h13, increase a variety of translational errors and a subset of the mutants show decreased association between 30S and 50S ribosomal subunits. These results are consistent with the involvement of h13-h44 interactions in the alignment and packing of these helices in the 30S subunit and the importance of this helical alignment for tRNA selection and subunit-subunit interaction. [ABSTRACT FROM AUTHOR]

Summary 1. Life histories evolve as a response to multiple agents of selection, such as age-specific mortality, resource availability or environmental fluctuations. Predators can affect life-history evolution directly, by increasing the mortality of prey, and indirectly, by modifying prey density and resources available to the survivors. Increasing survivor densities can intensify intraspecific competition and cause evolutionary changes in their selectivity, also affecting nutrient acquisition. 2. Here, we show that different life-history traits in guppies ( Poecilia reticulata) are correlated with differences in resource consumption and prey selectivity. We examined differences in wild-caught guppy diet among stream types with high (HP) and low predation (LP) pressure and how they are related to benthic invertebrate biomass. Fish and invertebrate samples were collected from two HP and two LP reaches of two distinct study rivers in Trinidad. 3. Our results reveal a strong association between life history and diet. Guppies from HP environments mature earlier and have higher fecundity and reproductive allotment than those from LP environments. Prior work revealed that their population densities are lower and that they grow faster than their LP counterparts. Here, we show that these life-history differences are repeated and that HP guppies feed primarily on invertebrates. In contrast, guppies from LP sites feed primarily on detritus and algae, which are a poorer quality food. LP guppies fed on invertebrates according to their availability, while HP guppies were selective towards those invertebrates with the lower carbon/nitrogen body ratio and thus with higher nutritional value. 4. Our study suggests that as predators shape the life histories of their prey and alter prey population densities, they can also indirectly shape their prey's foraging and diet selectivity. This is, to our knowledge, the first report on how intraspecific differences in life-history traits are correlated with prey selectivity, where prey stoichiometry is included. Although there are clear limitations of association data, our study suggests that the patterns of resource use and life history evolve in concert with one another. However, further research is needed to investigate the possible causal links between risk of predation, the indirect effects of predators on guppy population density, the evolution of life-history traits and nutrient acquisition. [ABSTRACT FROM AUTHOR]