Investigating Europa's Habitability with the Europa Clipper.

The habitability of Europa is a property within a system, which is driven by a multitude of physical and chemical processes and is defined by many interdependent parameters, so that its full characterization requires collaborative investigation. To explore Europa as an integrated system to yield a complete picture of its habitability, the Europa Clipper mission has three primary science objectives: (1) characterize the ice shell and ocean including their heterogeneity, properties, and the nature of surface-ice-ocean exchange; (2) characterize Europa's composition including any non-ice materials on the surface and in the atmosphere, and any carbon-containing compounds; and (3) characterize Europa's geology including surface features and localities of high science interest. The mission will also address several cross-cutting science topics including the search for any current or recent activity in the form of thermal anomalies and plumes, performing geodetic and radiation measurements, and assessing high-resolution, co-located observations at select sites to provide reconnaissance for a potential future landed mission. Synthesizing the mission's science measurements, as well as incorporating remote observations by Earth-based observatories, the James Webb Space Telescope, and other space-based resources, to constrain Europa's habitability, is a complex task and is guided by the mission's Habitability Assessment Board (HAB).

Direct observations of melting, freezing, and ocean circulation in an ice shelf basal crevasse.

Ocean conditions near the grounding zones of Antarctica's ice shelves play a key role in controlling the outflow and mass balance of the ice sheet. However, ocean observations in these regions are largely absent. Here, we present a detailed spatial survey collected with an underwater vehicle in a basal crevasse located in the ocean cavity at the Ross Ice Shelf grounding zone. The observations depict fine-scale variability in ocean forcing that drives asymmetric melting along the lower crevasse sidewalls and freezing in the upper reaches of the crevasse. Freshwater release from melting at depth and salt rejection from freezing above drives an overturning circulation. This vertical circulation pattern overlays a dominant throughflow jet, which funnels water parallel to the coastline, orthogonal to the direction of tidal currents. Importantly, these data reveal that basal crevasses influence ocean circulation and mixing at ice shelf grounding zones to an extent previously unknown.

Exploring the Interior of Europa with the Europa Clipper.

The Galileo mission to Jupiter revealed that Europa is an ocean world. The Galileo magnetometer experiment in particular provided strong evidence for a salty subsurface ocean beneath the ice shell, likely in contact with the rocky core. Within the ice shell and ocean, a number of tectonic and geodynamic processes may operate today or have operated at some point in the past, including solid ice convection, diapirism, subsumption, and interstitial lake formation. The science objectives of the Europa Clipper mission include the characterization of Europa's interior; confirmation of the presence of a subsurface ocean; identification of constraints on the depth to this ocean, and on its salinity and thickness; and determination of processes of material exchange between the surface, ice shell, and ocean. Three broad categories of investigation are planned to interrogate different aspects of the subsurface structure and properties of the ice shell and ocean: magnetic induction, subsurface radar sounding, and tidal deformation. These investigations are supplemented by several auxiliary measurements. Alone, each of these investigations will reveal unique information. Together, the synergy between these investigations will expose the secrets of the Europan interior in unprecedented detail, an essential step in evaluating the habitability of this ocean world.

Suppressed basal melting in the eastern Thwaites Glacier grounding zone.

Thwaites Glacier is one of the fastest-changing ice-ocean systems in Antarctica1-3. Much of the ice sheet within the catchment of Thwaites Glacier is grounded below sea level on bedrock that deepens inland4, making it susceptible to rapid and irreversible ice loss that could raise the global sea level by more than half a metre2,3,5. The rate and extent of ice loss, and whether it proceeds irreversibly, are set by the ocean conditions and basal melting within the grounding-zone region where Thwaites Glacier first goes afloat3,6, both of which are largely unknown. Here we show-using observations from a hot-water-drilled access hole-that the grounding zone of Thwaites Eastern Ice Shelf (TEIS) is characterized by a warm and highly stable water column with temperatures substantially higher than the in situ freezing point. Despite these warm conditions, low current speeds and strong density stratification in the ice-ocean boundary layer actively restrict the vertical mixing of heat towards the ice base7,8, resulting in strongly suppressed basal melting. Our results demonstrate that the canonical model of ice-shelf basal melting used to generate sea-level projections cannot reproduce observed melt rates beneath this critically important glacier, and that rapid and possibly unstable grounding-line retreat may be associated with relatively modest basal melt rates.

The Bioburden and Ionic Composition of Hypersaline Lake Ices: Novel Habitats on Earth and Their Astrobiological Implications.

We present thermophysical, biological, and chemical observations of ice and brine samples from five compositionally diverse hypersaline lakes in British Columbia's interior plateau. Possessing a spectrum of magnesium, sodium, sulfate, carbonate, and chloride salts, these low-temperature high-salinity lakes are analogs for planetary ice-brine environments, including the ice shells of Europa and Enceladus and ice-brine systems on Mars. As such, understanding the thermodynamics and biogeochemistry of these systems can provide insights into the evolution, habitability, and detectability of high-priority astrobiology targets. We show that biomass is typically concentrated in a layer near the base of the ice cover, but that chemical and biological impurities are present throughout the ice. Coupling bioburden, ionic concentration, and seasonal temperature measurements, we demonstrate that impurity entrainment in the ice is directly correlated to ice formation rate and parent fluid composition. We highlight unique phenomena, including brine supercooling, salt hydrate precipitation, and internal brine layers in the ice cover, important processes to be considered for planetary ice-brine environments. These systems can be leveraged to constrain the distribution, longevity, and habitability of low-temperature solar system brines-relevant to interpreting spacecraft data and planning future missions in the lens of both planetary exploration and planetary protection.

Enveloped Virus Inactivation on Personal Protective Equipment by Exposure to Ozone.

Ozone is a highly oxidizing gas easily generated from atmospheric oxygen with inexpensive equipment and is commonly used for the disinfection of municipal water, foods, and surfaces. We report tests of the ability of ozone to inactivate enveloped respiratory viruses (influenza A virus and respiratory syncytial virus), chosen as more easily handled surrogates for SARS-CoV-2, on N95 respirators and other personal protective equipment (PPE) commonly used in hospitals. At 20 ppm, an ozone concentration easily achieved by standard commercial equipment, the viruses were inactivated with high efficiency as long as the relative humidity was above a threshold value of approximately 50%. In the absence of humidity control, disinfection is more variable and requires considerably longer exposure under relatively dry conditions. This report extends the observations of a previous publication (http://doi.org/10.1080/01919510902747969) to hospital-relevant materials and provides additional details about the relationship of humidity to the antiviral activity of ozone. Home CPAP disinfection devices using ozone can provide effective results for individuals. Ozone did not appear to degrade any of the materials tested except for elastic bands if strained during treatment (such as by the pressure exerted by stapled attachment to N95 respirators). The filtration efficiency of N95 respirator material was not compromised. Overall, we recommend exposures of at least 40 minutes to 20 ppm ozone and >70% relative humidity at ambient temperatures (21-24°C) for 4-log (99.99%) reduction of viral infectivity on a variety of PPE, including gowns, face shields, and respirators. Shorter exposure times are likely to be effective under these conditions, but at the risk of some variability for different materials. Higher ozone concentrations and higher humidity levels promoted faster inactivation of viruses. Our work suggests that ozone exposure can be a widely accessible method for disinfecting PPE, permitting safer re-use for healthcare workers and patients alike in times of shortage.

Acute Responses of Functional Electrical Stimulation Cycling on the Ventilation-to-CO2 Production Ratio and Substrate Utilization After Spinal Cord Injury.

BACKGROUND: Ventilation-to-carbon dioxide ratio is comparable with peak oxygen uptake in the prognosis of cardiovascular disorders. Currently, there are no established indices to determine the submaximal effects of functional electrical stimulation on cardiovascular performance in persons with spinal cord injury. OBJECTIVE: To determine the effects of an acute bout of functional electrical stimulation-lower extremity cycling on ventilation, carbon dioxide production, ventilation-to-carbon dioxide ratio, and substrate utilization in people with motor complete spinal cord injury. DESIGN: Observational cross-sectional design. SETTING: Clinical laboratory setting. PARTICIPANTS: Ten individuals with motor complete spinal cord injury. METHODS: Participants were allowed to cycle until fatigue. The effects of functional electrical stimulation on ventilation, carbon dioxide production, ventilation-to-carbon dioxide ratio, and substrate utilization were measured with a portable metabolic cart (COSMED K4b2). Body composition was determined with bioelectrical impedance. RESULTS: Resting and warm-up ventilation were 8.15 ± 3.5 L/min and 8.15 ± 2.8 L/min, respectively. Functional electrical stimulation increased ventilation significantly (14.5 ± 6.4 L/min), which remained significantly elevated (13.3 ± 4.3 L/min) during the recovery period. During resting and warm-up phases, the ventilation-to-carbon dioxide ratios were 41 ± 4.8 and 38 ± 5.4, respectively. Functional electrical stimulation decreased the ventilation-to-carbon dioxide ratio significantly to 31.5 ± 4, which remained significantly reduced during the recovery period (34.4 ± 3). Functional electrical stimulation relied primarily on carbohydrate utilization (188 ± 160 g/day to 574 ± 324 g/day; P = .001) with no changes in fat utilization (77.5 ± 28 g/day to 93.5 ± 133.6 g/day; P = .7) from resting to exercise periods. Significant relationships were noted between carbohydrate utilization during functional electrical stimulation and carbon dioxide (r = 0.98; P = .00010) production. The percentage whole body fat-free mass was negatively related to the exercise ventilation-to-carbon ratio (r = -0.66; P = .045). CONCLUSIONS: An acute bout of functional electrical stimulation resulted in a significant drop in the ventilation-to-carbon ratio, accompanied with a reliance on carbohydrate utilization and a diminished capacity to utilize fat as a substrate. Fat-free mass may be associated with a decrease in ventilation to carbon dioxide ratio and an increase in carbohydrate utilization in persons with spinal cord injury.

Initiating statistical process control to improve quality outcomes in colorectal surgery.

BACKGROUND: Unexpected variations in postoperative length of stay (LOS) negatively impact resources and patient outcomes. Statistical process control (SPC) measures performance, evaluates productivity, and modifies processes for optimal performance. The goal of this study was to initiate SPC to identify LOS outliers and evaluate its feasibility to improve outcomes in colorectal surgery. METHODS: Review of a prospective database identified colorectal procedures performed by a single surgeon. Patients were grouped into elective and emergent categories and then stratified by laparoscopic and open approaches. All followed a standardized enhanced recovery protocol. SPC was applied to identify outliers and evaluate causes within each group. RESULTS: A total of 1294 cases were analyzed--83% elective (n = 1074) and 17% emergent (n = 220). Emergent cases were 70.5% open and 29.5% laparoscopic; elective cases were 36.8% open and 63.2% laparoscopic. All groups had a wide range in LOS. LOS outliers ranged from 8.6% (elective laparoscopic) to 10.8% (emergent laparoscopic). Evaluation of outliers demonstrated patient characteristics of higher ASA scores, longer operating times, ICU requirement, and temporary nursing at discharge. Outliers had higher postoperative complication rates in elective open (57.1 vs. 20.0%) and elective lap groups (77.6 vs. 26.1%). Outliers also had higher readmission rates for emergent open (11.4 vs. 5.4%), emergent lap (14.3 vs. 9.2%), and elective lap (32.8 vs. 6.9%). Elective open outliers did not follow trends of longer LOS or higher reoperation rates. CONCLUSIONS: SPC is feasible and promising for improving colorectal surgery outcomes. SPC identified patient and process characteristics associated with increased LOS. SPC may allow real-time outlier identification, during quality improvement efforts, and reevaluation of outcomes after introducing process change. SPC has clinical implications for improving patient outcomes and resource utilization.

Process control to measure process improvement in colorectal surgery: modifications to an established enhanced recovery pathway.

BACKGROUND: After more than a decade of improvement, our enhanced recovery pathway had patients who had undergone laparoscopic colectomy going home a mean 3.7 days postoperatively. We wondered if adding a transverse abdominus plane block and intravenous acetaminophen to an established pathway would improve outcomes and resource use. OBJECTIVE: The aim of this study was to evaluate the impact of modification of an enhanced recovery pathway on patient outcomes. DESIGN: This was a case-matched study. METHODS: After the addition of transverse abdominus plane blocks and acetaminophen to the enhanced recovery pathway 12 months ago, review of a prospective database was performed. Patients were matched by procedure type, age, and sex. SETTINGS: This study was performed at a tertiary referral center. PATIENTS: Patients undergoing elective major laparoscopic colorectal surgery from 2010 to 2012 were included. MAIN OUTCOME MEASURES: The primary outcome measures were hospital length of stay, readmission rate, postoperative complications, and the cost of the hospital episode before and after the amendment of our enhanced recovery pathway. RESULTS: Two hundred eight elective major laparoscopic cases were evaluated. Both groups were similar in demographics and comorbidities. Length of stay was significantly shorter once transverse abdominus plane blocks and acetaminophen were introduced (p < 0.01), dropping from 3.7 to 2.6 days. There were significantly more complications in the prechange group (p = 0.02), but no significant differences in readmissions or mortality. Direct costs were similar, but there was a $500 increase in total margin per case (p = 0.004) with the pathway changes. With the use of statistical process control to examine the effect on outliers, there was significantly less variation in the mean length of stay (2.29 vs 1.90 days, p < 0.01) after the addition of transverse abdominus plane blocks and intravenous acetaminophen. LIMITATIONS: The single-surgeon, single-institution design was a limitation of this study. CONCLUSIONS: The addition of a transverse abdominus plane block and acetaminophen significantly reduced length of stay more than that seen with a previously established pathway. Statistical process control demonstrated that our pathway changes significantly reduced the spread of outliers around our mean length of stay.

Prone jackknife position is not necessary to achieve a cylindrical abdominoperineal resection: demonstration of the lithotomy position.

This video demonstrates a laparoscopic abdominal perineal resection for a fixed 4.8-cm mass involving the posterior and left rectal walls and left puborectalis, 2 cm from the anal verge (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A127). We detail the steps of the procedure, all completed in lithotomy, including lateral-to-medial dissection; identification and protection of the left ureter and presacral nerves; division of the inferior mesenteric artery; medial-to-lateral dissection, with meeting the previous dissection plane; total mesorectal excision and pelvic dissection; perineal dissection and layered closure; and abdominal inspection and colostomy creation. Total operative time was 181 minutes. The specimen total mesorectal excision was complete with a negative circumferential radial margin (greater than 1 cm). Final pathology was T3N2M0.

Comparative effectiveness of laparoscopic versus robot-assisted colorectal resection.

BACKGROUND: During the past 20 years, laparoscopy has revolutionized colorectal surgery. With proven benefits in patient outcomes and healthcare utilization, laparoscopic colorectal surgery has steadily increased in use. Robotic surgery, a new addition to colorectal surgery, has been suggested to facilitate and overcome limitations of laparoscopic surgery. Our objective was to compare the outcomes of robot-assisted laparoscopic resection (RALR) to laparoscopic resections (LAP) in colorectal surgery. METHODS: A national inpatient database was evaluated for colorectal resections performed over a 30-month period. Cases were divided into traditional LAP and RALR resection groups. Cost of robot acquisition and servicing were not measured. Main outcome measures were hospital length of stay (LOS), operative time, complications, and costs between groups. RESULTS: A total of 17,265 LAP and 744 RARL procedures were identified. The RALR cases had significantly higher total cost ($5,272 increase, p < 0.001) and direct cost ($4,432 increase, p < 0.001), significantly longer operating time (39 min, p < 0.001), and were more likely to develop postoperative bleeding (odds ratio 1.6; p = 0.014) than traditional laparoscopic patients. LOS, complications, and discharge disposition were comparable. Similar findings were noted for both laparoscopic colonic and rectal surgery. CONCLUSIONS: RALR had significantly higher costs and operative time than traditional LAP without a measurable benefit.

Tolerance values of benthic macroinvertebrates for stream biomonitoring: assessment of assumptions underlying scoring systems worldwide.

Tolerance values (TVs) based on benthic macroinvertebrates are one of the most widely used tools for monitoring the biological impacts of water pollution, particularly in streams and rivers. We compiled TVs of benthic macroinvertebrates from 29 regions around the world to test 11 basic assumptions about pollution tolerance, that: (1) Arthropoda are < tolerant than non-Arthropoda; (2) Insecta < non-Insecta; (3) non-Oligochaeta < Oligochaeta; (4) other macroinvertebrates < Oligochaeta + Chironomidae; (5) other macroinvertebrate taxa < Isopoda + Gastropoda + Hirudinea; (6) Ephemeroptera + Plecoptera + Trichoptera (EPT) < Odonata + Coleoptera + Heteroptera (OCH); (7) EPT < non-EPT insects; (8) Diptera < Insecta; (9) Bivalvia < Gastropoda; (10) Baetidae < other Ephemeroptera; and (11) Hydropsychidae < other Trichoptera. We found that the first eight of these 11 assumptions were supported despite regional variability. In addition, we examined the effect of Best Professional Judgment (BPJ) and non-independence of TVs among countries by performing all analyses using subsets of the original dataset. These subsets included a group based on those systems using TVs that were derived from techniques other than BPJ, and groups based on methods used for TV assignment. The results obtained from these subsets and the entire dataset are similar. We also made seven a priori hypotheses about the regional similarity of TVs based on geography. Only one of these was supported. Development of TVs and the reporting of how they are assigned need to be more rigorous and be better described.

Optimizing cost and short-term outcomes for elderly patients in laparoscopic colonic surgery.

BACKGROUND: Elderly patients often are regarded as high-risk for major abdominal surgery because of a lack of functional reserve and associated medical comorbidities. The goal of this study was to compare the cost of care and short-term outcomes of elderly and nonelderly patients undergoing laparoscopic colectomy. Our hypothesis was that elderly patients managed with laparoscopic colorectal surgery and an enhanced recovery protocol (ERP) can realize the same benefits of lower hospital length of stay (LOS) without increasing hospital costs or readmission rates. METHODS: Review of a prospective database identified all patients that underwent an elective laparoscopic colectomy from 2009 to 2012. Patients were stratified into elderly (≥70 years old) and nonelderly (<70 years old) cohorts. The main outcome measures were discharge disposition, hospital costs, hospital LOS, and 30-day readmission rates between the laparoscopic and open groups. RESULTS: A total of 302 nonelderly (66%) and 153 elderly (34%) patients were included in the analysis. The elderly cohort had significantly higher comorbidities than the nonelderly group. There were no mortalities. Operative variables (procedure time, blood loss, and intraoperative complications) were similar. At discharge, significantly more elderly patients required temporary nursing or home care. There were no significant differences in short-term outcomes of LOS, 30-day readmission rates, or costs for the episode of care between the two groups. CONCLUSIONS: Combining laparoscopic colectomy with an ERP is cost-effective and results in similar short-term outcomes for the elderly and nonelderly patients. Despite higher comorbidities, elderly patients realized the same benefits of shorter LOS with similar hospital costs and readmission rates.

Economic and ecological costs and benefits of streamflow augmentation using recycled water in a California coastal stream.

Streamflow augmentation has the potential to become an important application of recycled water in water scarce areas. We assessed the economic and ecological merits of a recycled water project that opted for an inland release of tertiary-treated recycled water in a small stream and wetland compared to an ocean outfall discharge. Costs for the status-quo scenario of discharging secondary-treated effluent to the ocean were compared to those of the implemented scenario of inland streamflow augmentation using recycled water. The benefits of the inland-discharge scenario were greater than the increase in associated costs by US$1.8M, with recreational value and scenic amenity generating the greatest value. We also compared physical habitat quality, water quality, and benthic macroinvertebrate community upstream and downstream of the recycled water discharge to estimate the effect of streamflow augmentation on the ecosystem. The physical-habitat quality was higher downstream of the discharge, although streamflow came in unnatural diurnal pulses. Water quality remained relatively unchanged with respect to dissolved oxygen, pH, and ammonia-nitrogen, although temperatures were elevated. Benthic macroinvertebrates were present in higher abundances, although the diversity was relatively low. A federally listed species, the California red-legged frog (Rana draytonii), was present. Our results may support decision-making for wastewater treatment alternatives and recycled water applications in Mediterranean climates.

Evaluation of inflammatory markers as predictors of hospital stay and unplanned readmission after colorectal surgery.

UNLABELLED: Hospital length of stay (LOS) and readmissions continue to be expensive and unexpected events following colorectal surgery (CRS) whether patients follow enhanced recovery pathways or traditional care. Predictors of these adverse events could facilitate identification and optimization of CRS patients. THE AIM OF THE STUDY: To examine the impact of white blood cell count (WBC) and C-reactive protein (CRP) levels as predictors of delayed recovery or hospital readmission following CRS. MATERIAL AND METHODS: Patients undergoing laparoscopic or open abdominal colorectal surgery by a single surgeon were managed using standardized enhanced recovery pathways. Those with postoperative day 2 CRP and white blood cell values were evaluated. Outcomes included 30-day hospital readmission rates and postoperative length of hospital stay. RESULTS: CRP values were available for 193 patients (86 Male, mean age 58.6 years). Ninety-nine patients had surgery for colon cancer, 23 for Crohn's disease, 19 for ulcerative colitis, 31 for diverticulitis and 18 for other reasons. Twenty patients (10.4%) were readmitted to the hospital within 30 days of surgery. POD2 CRP accurately predicted short length of hospital stay (p< 0.01). Average CRP was 6.3 in the LOS of < 3 days or less, and 11.7 in patients with LOS >4 days. The mean CRP of the readmission and non-readmission groups was 11.8 and 9.9, respectively (p=0.29). The average POD 2 WBC of the readmission and non-readmission groups was 10.6 and 9 respectively (p=0.01). CONCLUSION: A low POD2 CRP level was correlated with a shorter LOS, but it did not predict readmission. Conversely, POD2 WBC, and the difference in WBC from baseline were associated with readmission. These markers may be useful indicators to predict suitability of early discharge in an ERP. Further evaluation in prospective trials is warranted.

Extraction site location and incisional hernias after laparoscopic colorectal surgery: should we be avoiding the midline?

BACKGROUND: Laparoscopic colorectal procedures require specimen extraction. It is unclear whether extraction site affects the incidence of incisional hernia (IH). METHODS: Patients undergoing laparoscopic colectomy over a 6-year period were identified. Outcomes were compared between patients to evaluate the incidence of hernia. RESULTS: Among 480 laparoscopic colorectal procedures, extraction sites were midline (n = 305), muscle splitting (n = 128), Pfannenstiel (n = 26), and ostomy (n = 21). Average follow-up was 3.5 years. Age, gender, diagnosis, extraction incision length, and hospital stay were similar. The mean body mass index for all patients was 28 kg/m(2) and for those with IHs was 31 kg/m(2) (P = .008). The overall IH rate was 7%. Midline IHs accounted for 84% of all hernias, occurring in 8.9% of midline extractions (P < .05 vs nonmidline extractions). Hernia rates for muscle-splitting, Pfannenstiel, and ostomy site extractions were 2.3%, 3.8%, and 4.8%, respectively. CONCLUSIONS: Although midline hernia rates were lower than traditionally reported with open surgery, midline extraction sites have a higher chance of IH than nonmidline sites.

Discharge within 24 to 72 hours of colorectal surgery is associated with low readmission rates when using Enhanced Recovery Pathways.

BACKGROUND: Enhanced Recovery Pathways (ERPs) have demonstrated reduced hospital length of stay and improved outcomes after colorectal surgery. Concerns exist about increases in readmission rates. Laparoscopic colorectal surgery with an ERP can permit earlier discharge without compromising safety or increasing readmission rates. STUDY DESIGN: A review of a prospective database was performed for major elective colorectal procedures by a single surgeon. All patients followed a standardized ERP and discharge criteria. Patients were categorized by approach and day of discharge (DoD) of ≤ 1, ≤ 2, ≤ 3, ≤ 7, and >7 days. Main outcomes measures were length of stay and 30-day readmission rates in each group. RESULTS: Eight hundred and six cases (609 laparoscopic, 197 open) were identified during a 64-month period. Mean age was similar for the laparoscopic (59.1 years) and open (58.3 years) groups. Mean overall DoD was at 5 days (± 4.8 days); by approach, the mean laparoscopic DoD was at 3.9 days and open DoD was at 8.4 days. Twenty-nine percent were discharged within 48 hours (38% laparoscopic and 8% open) and 50% were discharged within 72 hours (62% laparoscopic and 19% open). Only 8.9% of all patients (n = 72) were readmitted (7.2% laparoscopic, 14.2% open). The cumulative readmission rate for laparoscopic patients in early DoD groups postoperative days 1, 2, and 3 were 0.2%, 1.6%, and 3.4%, respectively. CONCLUSIONS: Combining laparoscopy with an ERP optimizes patient care in colorectal surgery. The combination permits early discharge; 38% were discharged within 2 days and 62% within 3 days of surgery, with low readmission rates. These results support that early DoD is possible without compromising patient safety or increasing readmission rates. This might be a marker for low readmission rate, and suggests that readmission rate alone might not be an adequate marker of quality.

Simulation and its role in training.

Despite its short history, surgical simulation has been successfully introduced into surgical residency programs in an effort to augment training. A wide range of simulator types and levels of complexity have proven an effective teaching method for surgical trainees. They have been used for training in areas such as general surgery, urology, gynecology, and ophthalmology among others. Coincident with the introduction of simulators is the need for objective evaluation of skills learned on them, which has led to the development and validation of multiple evaluation tools. This article evaluates the drivers for simulation, types of simulators, training, and evaluation of them especially as it pertains to laparoscopic colorectal surgery.

Integrating hospital administrative data to improve health care efficiency and outcomes: "the socrates story".

Evaluation of health care outcomes has become increasingly important as we strive to improve quality and efficiency while controlling cost. Many groups feel that analysis of large datasets will be useful in optimizing resource utilization; however, the ideal blend of clinical and administrative data points has not been developed. Hospitals and health care systems have several tools to measure cost and resource utilization, but the data are often housed in disparate systems that are not integrated and do not permit multisystem analysis. Systems Outcomes and Clinical Resources AdministraTive Efficiency Software (SOCRATES) is a novel data merging, warehousing, analysis, and reporting technology, which brings together disparate hospital administrative systems generating automated or customizable risk-adjusted reports. Used in combination with standardized enhanced care pathways, SOCRATES offers a mechanism to improve the quality and efficiency of care, with the ability to measure real-time changes in outcomes.

Copolymers of 2-(9H-carbazol-9-yl)ethyl 2-methylacrylate and 4-[5-(4-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]phenyl 2-methylacrylate: correlating hole drift mobility and electronic structure calculations with electroluminescence.

Methacrylate monomers functionalized with pendant carbazole and oxadiazole moieties were copolymerized into random copolymers with varying carbazole/oxadiazole ratios. Specifically, the monomers of 2-(9H-carbazol-9-yl)ethyl 2-methylacrylate (CE) and 4-[5-(4-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]phenyl 2-methylacrylate (tBPOP) were copolymerized in various ratios, and the inherent hole drift mobilities were assessed through time-of-flight techniques. At a field strength of 345 kV/cm, the homopolymer PCE exhibited a hole mobility of 5.9 x 10(-7) cm(2)/V.s, which was approximately twice the value of the technologically important poly(9-vinylcarbazole), which exhibited a value of 2.8 x 10(-7) cm(2)/V.s. The range of hole mobilities in the copolymers varied from 2.4 x 10(-8) cm(2)/V.s for copolymers containing 50 mol % of the carbazole-containing monomer residue to 3.0 x 10(-7) cm(2)/V.s for copolymers that incorporated 88 mol % of the residue. Density functional theory (B3LYP/6-21G*) and optical absorption derived highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies of CE were -5.39 and -1.94 eV, respectively, while the corresponding oxadiazole monomer (tBPOP) had a HOMO energy of -5.99 eV and a LUMO energy of -2.23 eV. The mean luminous efficiency of coumarin 6 doped single-layer devices constructed from the poly(CE-co-tBPOP) copolymers indicated a relatively flat efficiency of ca. 0.25 cd/A over a wide carbazole mole fraction content of 0.30-0.70.