Widespread Production of Polyunsaturated Aldehydes by Benthic Diatoms of the North Pacific Ocean's Salish Sea.

Diatoms are key primary producers across marine, freshwater, and terrestrial ecosystems. They are responsible for photosynthesis and secondary production that, in part, support complex food webs. Diatoms can produce phytochemicals that have transtrophic ecological effects which increase their competitive fitness. Polyunsaturated aldehydes (PUAs) are one class of diatom-derived phytochemicals that are known to have allelopathic and anti-herbivory properties. The anti-herbivory capability of PUAs results from their negative effect on grazer fecundity. Since their discovery, research has focused on their production by pelagic marine diatoms, and their effects on copepod egg production, hatching success, and juvenile survival and development. Few investigations have explored PUA production by the prolific suite of benthic marine diatoms, despite their importance to coastal trophic systems. In this study, we tested eight species of benthic diatoms for the production of the bioactive PUAs 2,4-heptadienal, 2,4-octadienal, and 2,4-decadienal. Benthic diatom species were isolated from the Salish Sea, an inland sea within the North Pacific ecosystem. All species were found to be producers of at least two PUAs in detectable concentrations, with five species producing all three PUAs in quantifiable concentrations. Our results indicate that production of PUAs from Salish Sea benthic diatoms may be widespread, and thus these compounds may contribute to benthic coastal food web dynamics through heretofore unrecognized pathways. Future studies should expand the geographic scope of investigations into benthic diatom PUA production and explore the effects of benthic diatoms on benthic consumer fecundity.

Posterior mesh inguinal hernia repairs: a propensity score matched analysis of laparoscopic and robotic versus open approaches.

PURPOSE: International guidelines suggest the use of lapro-endoscopic technique for primary unilateral inguinal hernia (IHR) because of lower postoperative pain and reduction in chronic pain. It is unclear if the primary benefit is due to the minimally invasive approach, the posterior mesh position or both. Further research evaluating posterior mesh placement using open preperitoneal techniques is recommended. A potential benefit of open preperitoneal repair is the avoidance of general anesthesia, as these repairs can be performed under local anesthesia. This study compares clinical and patient-reported outcomes after unilateral laparo-endoscopic, robotic, and open posterior mesh IHRs. METHODS: We performed a propensity score matched analysis of patients undergoing IHR between 2012 and 2021 in the Abdominal Core Health Quality Collaborative registry. 10,409 patients underwent a unilateral IHR via a posterior approach. Hernia repairs were performed via minimally invasive surgery (MIS) which includes laparoscopic and robotic transabdominal preperitoneal (TAPP), laparoscopic totally extraperitoneal (TEP), or open transrectus preperitoneal/open preperitoneal (TREPP/OPP) approaches. Propensity score matching (PSM) utilizing nearest neighbor matching accounted for differences in baseline characteristics and possible confounding variables between groups. We matched 816 patients in the MIS cohort with 816 patients in the TREPP/OPP group. Outcomes included patient reported quality of life, hernia recurrence, and postoperative opioid use. RESULTS: Improvement was seen after TREPP/OPP as compared to MIS IHR in EuraHS at 30 days (Median(IQR) 7.0 (2.0-16.64) vs 10 (2.0-24.0); OR 0.69 [0.55-0.85]; p = 0.001) and 6 months (1.0 (0.0-4.0) vs 2.0 (0.0-4.0); OR 0.63 [0.46-85]; p = 0.002), patient-reported opioid use at 30-day follow-up (18% vs 45% OR 0.26 [0.19-0.35]; p < 0.001), and rates of surgical site occurrences (0.8% vs 4.9% OR 0.16 [0.06-0.35]; p < 0.001). There were no differences in EuraHS scores and recurrences at 1 year. CONCLUSIONS: This study demonstrates a potential benefit of open posterior mesh placement over MIS repair in short-term quality of life and seroma formation with equivalent rates of hernia recurrence. Further study is needed to better understand these differences and determine the reproducibility of these findings outside of high-volume specialty centers.

Importance of communication of CT indication for imaging yield in patients with gastrointestinal bleed.

PURPOSE: The indications for requesting a diagnostic test are important for the selection and timing of imaging protocols. We sought to evaluate the diagnostic yield and impact on patient disposition when evaluating computed tomography (CT) of the abdomen and pelvis in adult patients presenting with gastrointestinal bleeding (GIB) to the Emergency Department (ED). METHODS: This study was an observational cohort study of consecutive adult ED patients with ICD10 codes related to GIB between 5/5/2018 and 6/1/2020. CT reports were reviewed for indications, exam type and findings. Reports were classified as positive (active bleeding, recent bleeding or suspected etiology for GIB), negative or other significant findings. Methodological guidelines for reporting observational studies were followed (STROBE). RESULTS: Among 943 patients with GIB during the study period, 33% (n = 312) had an abdominopelvic CT ordered. Most CTs included contrast, 64.1% (n = 200) used a single portal venous phase and 28.9% (n = 90) were multi-phase. CT identified active bleeding in 4.2% (n = 13/312) and intraluminal blood in 2.9% (n = 9/312) patients. Patients that had GIB indications on the CT order (n = 142) were more likely to receive a multiphase study compared to those without GIB indication (n = 94) (43.0% vs. 8.5%, difference 34.5%, 95% CI 23.7% to 43.7%, p < 0.0001). Patients that received multiphase studies were more likely to have a source of GIB identified compared to single-phase (18.9% vs 1.5%, OR 15.3, 95% CI 4.4 to 53.7, p < 0.0001). In 40.3% (n = 117/290) of patients without bleeding, an intra-abdominal cause for their symptoms was identified. Those with GIB or with an identified cause were more likely to be admitted. CONCLUSIONS: One-third of patients evaluated in the ED with GIB had a CT ordered. Active GIB was detected more often when multiphase exams were performed. Multiphase exams are done more often if GIB is listed in the CT indication. When a CT is positive, patients are more likely to be admitted or observed. Accurate indications are critical to optimize exam performance.

Surf smelt accelerate usage of endogenous energy reserves under climate change.

Surf smelt (Hypomesus pretiosus) are ecologically critical forage fish in the North Pacific ecosystem. As obligate beach spawners, surf smelt embryos are exposed to wide-ranging marine and terrestrial environmental conditions. Despite this fact, very few studies have assessed surf smelt tolerance to climate stressors. The purpose of this study was to examine the interactive effects of climate co-stressors ocean warming and acidification on the energy demands of embryonic and larval surf smelt. Surf smelt embryos and larvae were collected from spawning beaches and placed into treatment basins under three temperature treatments (13°C, 15°C, and 18°C) and two pCO2 treatments (i.e. ocean acidification) of approximately 900 and 1900 µatm. Increased temperature significantly decreased yolk size in surf smelt embryos and larvae. Embryo yolk sacs in high temperature treatments were on average 7.3% smaller than embryo yolk sacs from ambient temperature water. Larval yolk and oil globules mirrored this trend. Larval yolk sacs in the high temperature treatment were 45.8% smaller and oil globules 31.9% smaller compared to larvae in ambient temperature. There was also a significant positive effect of acidification on embryo yolk size, indicating embryos used less maternally-provisioned energy under acidification scenarios. There was no significant effect of either temperature or acidification on embryo heartrates. These results indicate that near-future climate change scenarios may impact the energy demands of developing surf smelt, leading to potential effects on surf smelt fitness and contributing to variability in adult recruitment.

Are perioperative outcomes in cancer-related ventral incisional hernia repair worse than in the general population? An Abdominal Core Health Quality Collaborative (ACHQC) database study.

PURPOSE: Patients with a history of cancer-related abdominal surgery undergoing incisional hernia repair (IHR) are highly heterogenous and increasingly prevalent. We explored whether cancer surgery should be considered an independent risk factor for worse IHR perioperative outcomes. METHODS: Patients undergoing IHR between 2018 and 2020 were identified within the Abdominal Core Health Quality Collaborative (ACHQC). Regression models were used to assess associations between cancer operation history and 30 d surgical site occurrences-exclusive of infection (SSO-EIs), surgical site infections (SSIs), reoperations, time to recurrence, and quality of life (QoL) scores. Cancer cohort subgroup analysis was performed for operative approach and mesh location. RESULTS: 8019 patients who underwent IHR were identified in the ACHQC, 1321 of which had a history of cancer operation. Cancer cohort patients were more likely to be older, males with a higher ASA status and lower BMI, and have longer and wider hernias (p < 0.001). After adjusting for confounding, the cancer cohort was less likely to experience SSO-EIs (OR 0.74, 95% CI 0.59-0.94 p = 0.0092) and showed lower odds of SSIs, reoperations, and recurrence (SSI OR 0.7, 95% CI 0.47-1.05, p = 0.0542; reoperation OR 0.66, 95% CI 0.37-1.17, p = 0.1002; recurrence OR 0.8, 95% CI 0.63-1.02, p = 0.08). There was no difference in postoperative QoL scores between cohorts. There were also no differences in perioperative or QoL outcomes within the cancer cohort based on operative approach or mesh location. CONCLUSION: These data show no evidence that history of cancer operation predisposes patients to worse incisional hernia repair perioperative or quality of life outcomes.

Acceptability and barriers to adopting physical therapy and rehabilitation as standard of care in hernia disease: a prospective national survey of providers and preliminary data.

PURPOSE: Physical therapy (PT) and rehabilitation are widely utilized in a variety of disease processes to improve function, return to activities of daily living (ADLs), and promote overall recovery. However, hernia repair has struggled to adopt this practice despite operations occurring in one of the most dynamic parts of the body - the abdominal core. This study sought to understand perspectives and perceived barriers regarding the incorporation of PT and rehabilitation in hernia care. METHODS: A standardized rehabilitation protocol was developed by the Abdominal Core Health Quality Collaborative (ACHQC), a national quality improvement initiative specific to hernia disease, and launched in 2019. Empiric data from the ACHQC was then obtained to describe preliminary utilization. A prospective electronic survey was then deployed to all surgeons participating in the ACHQC to aid in interpreting the identified trends. The survey included questions regarding the current use of PT in their practice, as well as further opinions on the functionality, benefit, and barriers to its use. RESULTS: We identified 1,544 patients who were listed as receiving some form of postoperative rehabilitation, of which 992 (64.2%) had a primary diagnosis of ventral hernia and 552 (35.8%) had an inguinal hernia. Among patients who had a ventral hernia, 863 (87.0%) received self-directed rehabilitation exercises compared to 488 (88.4%) of inguinal hernia patients. The subsequent survey exploring these trends was completed by 46 ACHQC surgeons (10.2%). More than half (52%) reported using PT for hernia patients, primarily in abdominal wall reconstruction cases (92%). Of those who did not report using PT, 50% cited unknown clinical benefit and another 27% cited unknown PT resources. PT utilization was typically concentrated to the postoperative period (58%), while 42% reported also using it preoperatively. Despite 72% of respondents citing a perceived benefit of PT in hernia patients, overall use of PT was primarily reported as 'occasional' by 42%, with another 27% reporting 'rarely.' Perceived benefits of PT included increased core strength, stability, mobility, patient satisfaction, education, independence, earlier return to work and ADLs, overall improved recovery, and decreased risk of postoperative issues. Reported barriers to implementing PT in practice or adapting the ACHQC Rehabilitation Protocol included lack of education, lack of evidence of clinical benefit, and difficulties operationalizing the protocol. CONCLUSION: A national survey of hernia surgeons demonstrated willingness to adopt PT and rehabilitation protocols in their clinical practices and noted a high perceived benefit to patients. However, lack of education and evidence regarding the protocol may represent important barriers to overcome in widely disseminating these resources to patients. These gaps can be addressed through dedicated educational venues and additional studies establishing PT and rehabilitation as critical future adjuncts for the recovery of hernia repair patients.

Surgical management of infected abdominal wall mesh: an analysis using the American Hernia Society Quality Collaborative.

INTRODUCTION: Several management strategies exist for the treatment of infected abdominal mesh. Using the American Hernia Society Quality Collaborative, we examined management patterns and 30-day outcomes of infected mesh removal with concomitant incisional hernia repair. METHODS: All patients undergoing incisional hernia repair with removal of infected mesh were identified. A complete repair (CR) was defined as fascial closure with mesh; a partial repair (PR) was defined as fascial closure without mesh or no fascial closure with mesh. A two-tailed p value less than or equal to 0.05 was considered statistically significant. RESULTS: A total of 282 patients were identified: 136 patients in CR group and 146 patients in PR group. Patients had similar comorbidities but differed in wound class (class IV: 55% CR vs 83% SR, p < 0.001) and incidence of associated concomitant colorectal procedures (5% CR vs 18% SR, p = 0.015). Sublay placement was used primarily in CR (94%) compared to PR (52% inlay, 48% sublay). When comparing CR to PR, length of stay (median 6, p = 0.69), complications (40% vs 44%, p = 0.44), surgical site infections (16% vs 21%, p = 0.27), surgical site occurrence (30% vs 35%, p = 0.45), and readmission within 30 days (9% vs. 13%) were not statistically different. CONCLUSIONS: Analysis of data from a multicenter hernia registry comparing CR and PR during infected mesh removal and concurrent incisional hernia repair has not identified higher rates of short-term complications between groups in the presence of infection.

Is there an advantage to laparoscopy over open repair of primary umbilical hernias in obese patients? An analysis of the Americas Hernia Society Quality Collaborative (AHSQC).

PURPOSE: The most common techniques used to repair umbilical hernias are open and laparoscopic. As the obesity epidemic in the United States is growing, it is essential to understand how this morbidity affects umbilical hernia repairs. This study compares laparoscopic versus open umbilical hernia repairs in obese patients. METHODS: All patients with body mass index (BMI) ≥ 30 kg/m2 who underwent elective, open or laparoscopic repair of a primary umbilical hernia with mesh were identified from the Americas Hernia Society Quality Collaborative (AHSQC). A retrospective review of the prospectively collected data was conducted. Outcomes of interest included surgical site infections (SSI), surgical site occurrences requiring procedural intervention (SSOPI), hernia-related quality-of-life survey (HerQles), and long-term recurrence. A logistic regression model was used to generate propensity scores. RESULTS: Of 1507 patients who met the inclusion criteria, 322 were laparoscopic, and 1185 were open cases. The laparoscopic group had higher mean BMI (37 ± 6 vs. 35 ± 5 kg/m2 , P < 0.001 ) and mean hernia width (3 cm ± 1 vs. 2 cm ± 2, P < 0.001). Using a propensity score model, we controlled for several clinically relevant covariates. Propensity score adjustment showed no differences in the 30-day HerQles score (OR 0.93, 95% CI 0.58-1.49), SSI (OR 1.57, 95% CI 0.52-4.77), SSOPI (OR 2.85, 95% CI 0.84-9.62) or hernia recurrence (hazard ratio 0.86, 95% CI 0.50-1.49). CONCLUSION: In obese patients with primary umbilical hernias, there is likely no benefit to laparoscopy over open umbilical hernia repair with mesh with regard to wound morbidity. Although, the long-term recurrence also showed no difference between these two approaches, overall follow up was lacking.

Is concomitant cholecystectomy safe during abdominal wall reconstruction? An AHSQC analysis.

PURPOSE: Unlike routine ventral hernia repair, abdominal wall reconstruction (AWR) can results in large pieces of mesh and extensive manipulation of the intra-abdominal contents, rendering subsequent laparoscopic cholecystectomy challenging. This study addresses the additional wound morbidity of concomitant cholecystectomy. METHODS: The Americas Hernia Society Quality Collaborative (AHSQC) was retrospectively reviewed and logistic regression modeling was used to control for multiple covariates. Patients that underwent open AWR with cholecystectomy were compared to a similar group of patients undergoing uncomplicated, open, clean, AWR alone. RESULTS: 130 patients undergoing concomitant cholecystectomy were compared to a control group of 6440 patients. The addition of a cholecystectomy did not cause a significant change in wound morbidity (SSI: p = 0.16; SSOPI: p = 0.65). CONCLUSIONS: This study noted that a concomitant cholecystectomy does not increase the wound morbidity as compared to an uncomplicated, clean, AWR. This provides support for consideration of routine cholecystectomy in patients with cholelithiasis undergoing AWR.

Elastography in the evaluation of liver allograft.

Elastography is an established technique in the evaluation of chronic liver diseases. While there is a large clinical experience and data available regarding the performance of elastography in native liver, elastography experience with liver grafts is limited and still growing. Both ultrasound-based elastography techniques and MR Elastography (MRE) are useful in the assessment of liver fibrosis in liver transplants. Technical modifications for performing elastography will be required for optimum evaluation of the graft. In general, caution needs to be exercised regarding the use of elastography immediately following transplantation as post-operative changes, perioperative conditions/complications, inflammation, and rejection can cause increased stiffness in the graft. In the follow-up, detection of increased stiffness with elastography is useful for predicting development of fibrosis in the graft. Adjunctive MRI or ultrasound with Doppler also provides comprehensive evaluation of anatomy, vascular anastomosis and patency, biliary tree, and stiffness for fibrosis. In this review, we provide a brief overview of elastography techniques available followed by the literature review of elastography in the evaluation of grafts and illustration with clinical examples.

The design of a line velocity interferometer for any reflector for inertial confinement experiments on the Z-machine.

A line VISAR (Velocity Interferometer System for Any Reflector) has been designed and commissioned at the Sandia National Laboratory's Z-machine. The instrument consists of an F/2 collection system, beam transport, and an interferometer table that contains two Mach-Zehnder type interferometers and an eight channel Gated Optical Imaging (GOI) system. The VISAR probe laser operates at the 532 nm wavelength, and the GOI bandpass is 540-600 nm. The output of each interferometer is passed to an optical streak camera with four selectable sweep speeds. The system is designed with three interchangeable optics modules to select a full field of view of 1 mm, 2 mm, or 4 mm. The optical beam transport system connects the target image plane to the interferometers and the gated optical imagers. The target is integrated into a sacrificial final optics assembly that is integral to the transport beamline.

Intraperitoneal versus retromuscular mesh placement for open incisional hernias: an analysis of the Americas Hernia Society Quality Collaborative.

BACKGROUND: Incisional hernia repair with mesh improves long-term outcomes, but the ideal mesh position remains unclear. This study compared intraperitoneal versus retromuscular or preperitoneal sublay (RPS) mesh positions for open incisional hernia repairs. METHODS: All patients who had elective open incisional hernia repairs were identified retrospectively in the Americas Hernia Society Quality Collaborative database. The primary outcome was the rate of 30-day surgical-site infection (SSI). Other outcomes of interest included 30-day surgical-site occurrences requiring procedural intervention (SSOPI), hernia-related quality-of-life survey (HerQLes) scores and long-term recurrence. A logistic model was used to generate propensity scores for mesh position using several clinically relevant co-variables. Regression models adjusting for propensity score and baseline characteristics were developed to assess the effect of mesh placement. RESULTS: A total of 4211 patients were included in the study population: 587 had intraperitoneal mesh and 3624 had RPS mesh. Analysis with propensity score adjustment provided no evidence for differences in SSOPI (odds ratio (OR) 0·79, 95 per cent c.i. 0·49 to 1·26) and SSI (OR 0·91, 0·50 to 1·67) rates or HerQLes scores at 30 days (OR 1·20, 0·79 to 1·82), or recurrence rates (hazard ratio 1·28, 0·90 to 1·82). CONCLUSION: Mesh position had no effect on short- or long-term outcomes, including SSOPI and SSI rates, HerQLes scores and long-term recurrence rates.

ANTECEDENTES: La reparación de una eventración con malla mejora los resultados a largo plazo, pero sigue sin estar definida cuál es la posición ideal de colocación de la malla. Este estudio comparó los resultados de la reparación abierta de una eventración con malla en posición intraperitoneal versus retromuscular o preperitoneal (retromuscular or preperitoneal sublay, RPS). MÉTODOS: Se identificaron de forma retrospectiva todos los pacientes a los que se reparó una eventración por via abierta en el Americas Hernia Society Quality Collaborative. La variable principal fue la tasa de infección de la herida quirúrgica (surgical site infections, SSI) a los 30 días. Se analizaron también las incidencias acaecidas en la herida que hubieran precisado algún tratamiento (surgical site occurrences requiring procedural intervention, SSOPI) dentro de los 30 días postintervención, los resultados de una encuesta de calidad de vida relacionada con la hernia (HerQles) y la recidiva a largo plazo. Se utilizó un modelo logístico con diferentes covariables clínicas relevantes para generar puntajes de propensión con respecto a la posición de malla. Para analizar el efecto de la posición de la malla, se desarrollaron diferentes modelos de regresión ajustados por las características basales y el puntaje de propensión. RESULTADOS: Se incluyeron en el estudio 4.211 pacientes, 587 con malla intraperitoneal y 3.624 con malla RPS. El análisis con ajuste por puntaje de propensión no mostró diferencias en SSOPI (razón de oportunidades, odds ratio, OR 0,624, i.c. del 95% 0,364-1,07), SSI (OR 0,927, i.c. del 95% 0,475-1,81), puntuación HerQles a 30 días (OR 1,19, i.c. del 95% 0,79-1,8) o en el índice de recidivas (OR 1,28, i.c. del 95% 0,897-1,82). CONCLUSIÓN: La posición de la colocación de la malla no tuvo efecto en los resultados a corto o largo plazo, incluidas las tasas de SSOPI y SSI, las puntuaciones de HerQles y la tasa de recidiva a largo plazo.

Hernia recurrence inventory: inguinal hernia recurrence can be accurately assessed using patient-reported outcomes.

PURPOSE: Relying solely on in-person encounters to assess long-term outcomes of hernia repair leads to substantial loss of information and patients lost-to-follow-up, hindering research and quality improvement initiatives. We aimed to determine if inguinal hernia recurrences could be assessed using the Ventral Hernia Recurrence Inventory (VHRI), a previously existing patient-reported outcome (PRO) tool that can be administered through the telephone and has already been validated for diagnosing ventral hernia recurrence. METHODS: A prospective, multicentric comparative study was conducted. Adult patients from two centers (United States and Brazil) at least 1 year after open or minimally invasive inguinal hernia repair were asked to answer the questions of the VHRI in relation to their prior repair. A physical exam was then performed by a blinded surgeon. Testing characteristics and diagnostic performance of the PRO were calculated. Patients with suspected recurrences were preferentially recruited. RESULTS: 128 patients were enrolled after 175 repairs. All patients answered the VHRI and were further examined, where a recurrence was present in 32% of the repairs. Self-reported bulge and patient perception of a recurrence were highly sensitive (84-94%) and specific (93-94%) for the diagnosis of an inguinal hernia recurrence. Test performance was similar in the American and Brazilian populations despite several baseline differences in demographic and clinical characteristics. CONCLUSION: The VHRI can be used to assess long-term inguinal hernia recurrence and should be reestablished as the Hernia Recurrence Inventory (HRI). Its implementation in registries, quality improvement efforts, and research could contribute to improving long-term follow-up rates in hernia patients.

Primary uncomplicated midline ventral hernias: factors that influence and guide the surgical approach.

BACKGROUND: Considering recently published high-level evidence on the management of primary midline ventral hernias, we set out to review current practices and reevaluate the literature surrounding this topic. METHODS: The Americas Hernia Society Quality Collaborative (AHSQC) was used to abstract all uncomplicated primary midline ventral hernias. The primary outcomes of interest were surgical approaches, including the use of mesh, the type and position of mesh, and the use of minimally invasive surgery (MIS). RESULTS: A total of 7030 met inclusion criteria; mean age of 52 ± 14, 71% male, with a median hernia width of 2 [1, 2]. A total 69% underwent mesh repair, while 31% underwent suture repair. The most commonly used mesh was permanent synthetic (98%), placed in either the intraperitoneal (46%) or preperitoneal (42%) spaces. The majority of repairs were performed through an open approach (72%). When mesh was used through an open approach (58%), the majority were patches (70%) placed in the preperitoneal space (50%). Through an MIS approach (95%), the majority were flat meshes (53%) placed in the intraperitoneal space (58%). CONCLUSION: Recent high-level literature recommends the use of mesh repair (flat mesh) in all patients with hernia width ≥ 1 cm. This evidence is limited to the use of flat mesh through an open approach. While AHSQC surgeons do offer mesh repair in the majority of cases, this is most commonly using a mesh patch, and is selective towards larger hernias and obese patients. Further research is required to evaluate the safety of mesh patches, and a mesh repair should be offered to a young non-obese healthy patient, as they benefit similarly from the use of mesh.

Direct and indirect effects of elevated CO2 are revealed through shifts in phytoplankton, copepod development, and fatty acid accumulation.

Change in the nutritional quality of phytoplankton is a key mechanism through which ocean acidification can affect the function of marine ecosystems. Copepods play an important role transferring energy from phytoplankton to higher trophic levels, including fatty acids (FA)-essential macronutrients synthesized by primary producers that can limit zooplankton and fisheries production. We investigated the direct effects of pCO2 on phytoplankton and copepods in the laboratory, as well as the trophic transfer of effects of pCO2 on food quality. The marine cryptophyte Rhodomonas salina was cultured at 400, 800, and 1200 µatm pCO2 and fed to adult Acartia hudsonica acclimated to the same pCO2 levels. We examined changes in phytoplankton growth rate, cell size, carbon content, and FA content, and copepod FA content, grazing, respiration, egg production, hatching, and naupliar development. This single-factor experiment was repeated at 12°C and at 17°C. At 17°C, the FA content of R. salina responded non-linearly to elevated pCO2 with the greatest FA content at intermediate levels, which was mirrored in A. hudsonica; however, differences in ingestion rate indicate that copepods accumulated FA less efficiently at elevated pCO2. A. hudsonica nauplii developed faster at elevated pCO2 at 12°C in the absence of strong food quality effects, but not at 17°C when food quality varied among treatments. Our results demonstrate that changes to the nutritional quality of phytoplankton are not directly translated to their grazers, and that studies that include trophic links are key to unraveling how ocean acidification will drive changes in marine food webs.

Transcriptional Regulation of icaADBC by both IcaR and TcaR in Staphylococcus epidermidis.

S. epidermidis is a primary cause of biofilm-mediated infections in humans due to adherence to foreign bodies. A major staphylococcal biofilm accumulation molecule is polysaccharide intracellular adhesin (PIA), which is synthesized by enzymes encoded by the icaADBC operon. Expression of PIA is highly variable among clinical isolates, suggesting that PIA expression levels are selected in certain niches of the host. However, the mechanisms that govern enhanced icaADBC transcription and PIA synthesis in these isolates are not known. We hypothesized that enhanced PIA synthesis in these isolates was due to function of IcaR and/or TcaR. Thus, two S. epidermidis isolates (1457 and CSF41498) with different icaADBC transcription and PIA expression levels were studied. Constitutive expression of both icaR and tcaR demonstrated that both repressors are functional and can completely repress icaADBC transcription in both 1457 and CSF41498. However, it was found that IcaR was the primary repressor for CSF41498 and TcaR was the primary repressor for 1457. Further analysis demonstrated that icaR transcription was repressed in 1457 in comparison to CSF41498, suggesting that TcaR functions as a repressor only in the absence of IcaR. Indeed, DNase I footprinting suggests IcaR and TcaR may bind to the same site within the icaR-icaA intergenic region. Lastly, we found mutants expressing variable amounts of PIA could rapidly be selected from both 1457 and CSF41498. Collectively, we propose that strains producing enhanced PIA synthesis are selected within certain niches of the host through several genetic mechanisms that function to repress icaR transcription, thus increasing PIA synthesis.IMPORTANCEStaphylococcus epidermidis is a commensal bacterium that resides on our skin. As a commensal, it protects humans from bacterial pathogens through a variety of mechanisms. However, it is also a significant cause of biofilm infections due to its ability to bind to plastic. Polysaccharide intercellular adhesin is a significant component of biofilm, and we propose that the expression of this polysaccharide is beneficial in certain host niches, such as providing extra strength when the bacterium is colonizing the lumen of a catheter, and detrimental in others, such as colonization of the skin surface. We show here that fine-tuning of icaADBC transcription, and thus PIA synthesis, is mediated via two transcriptional repressors, IcaR and TcaR.

Outcomes of transversus abdominis release in non-elective incisional hernia repair: a retrospective review of the Americas Hernia Society Quality Collaborative (AHSQC).

PURPOSE: Elective repair of large incisional hernias using posterior component separation with transversus abdominis release (TAR) has acceptable wound morbidity and long-term recurrence rates. The outcomes of using this reconstructive technique in the non-elective setting remains unknown. We aim to report 30-day outcomes of TAR in non-elective settings. METHODS: All patients undergoing open TAR in non-elective settings were identified within the Americas Hernia Society Quality Collaborative (AHSQC). A retrospective review was conducted and outcomes of interest were 30-day Surgical Site Infections (SSI), Surgical Site Occurrences (SSO), SSOs requiring procedural intervention (SSOPI), medical complications, and unplanned readmissions and reoperations. RESULTS: Fifty-nine patients met inclusion criteria. Mean BMI was 36.6 ± 8.9 kg/m2 and mean hernia width was 14.4 ± 7.2 cm. Forty (67.8%) were recurrent hernias. Pain (88%) and bowel obstruction (79.7%) were the most frequent indications for surgery. Surgical field was classified as clean in 69.5% of cases, with an 88% use of permanent synthetic mesh and fascial closure achieved in 93.2% of cases. There were 15 (25.4%) total wound events, 8 (13.6%) were SSIs. There were 8 (13.6%) SSOPIs, 6 of which were wound opening, 1 wound debridement, and 1 percutaneous drainage. At least one wound or medical complication was reported for 37% of the patients. There were no mortalities. CONCLUSION: Not surprisingly, TAR in the non-elective setting is associated with increased wound morbidity requiring procedural interventions and reoperations compared to what has previously been reported for elective cases. The long-term consequences of this wound morbidity with regard to hernia recurrence are as of yet unknown.

Variability in the time to initiation of CPR in continuously monitored pediatric ICUs.

AIM: To study the influence of patient characteristics and unit ergonomics and human factors on the time to initiation of CPR. METHODS: A single center study of children, 0 to 21 years old, admitted to an ICU who experienced cardiopulmonary arrest (CPA) requiring >1 min of chest compressions. Time of CPA was determined by analysis of continuous ECG, plethysmography, arterial blood pressure, and end-tidal CO2 (EtCO2) waveforms. Initiation of CPR was identified by the onset of cyclic artifact in the ECG waveform. Patient characteristics and unit ergonomics and human factors were examined including CPA cause, identification on the High-Risk Checklist (HRC), existing monitoring, ICU type, time of day, nursing shift change, and outcome. RESULTS: The median time from CPA to initiation of CPR was 50.5 s (IQR 26.5 to 127.5) in 36 CPAs. Forty-seven percent of patients experienced time from CPA to initiation of CPR of >1 min. There was no difference in CPA cause, ICU type, time of day, or nursing shift change. CONCLUSION: Nearly half of pediatric patients who experienced CPA in an ICU setting did not meet AHA guidelines for early initiation of CPR. This is an opportunity to study the recognition phase of CPA using continuous monitoring data with the aim of improving the understanding of and factors contributing to delays in initiation of CPR.

Pollination context alters female advantage in gynodioecious Silene vulgaris.

Gynodioecy, the co-occurrence of females and hermaphrodites, is arguably the most common angiosperm gender polymorphism in many florae. Females' ability to invade and persist among hermaphrodites depends, in part, on pollinators providing adequate pollination to females. We directly measured diurnal and nocturnal pollinators' contributions to female and hermaphrodite seed production in artificial populations of gynodioecious Silene vulgaris by experimentally restricting pollinator access. We found that female relative seed production in this system depended strongly on pollination context: females produced more than twice as many seeds as hermaphrodites in the context of abundant, nectar-collecting moths. Conversely, females showed no seed production advantage in the context of pollen-collecting syrphid flies and bees due to acutely hermaphrodite-biased visitation. We infer that variation in pollinator type, behaviour and abundance may be important for achieving the female relative fitness thresholds necessary for the maintenance of gynodioecy. Generally, our study illustrates how pollinator-mediated mechanisms may influence the evolution of breeding systems and associated suites of floral traits. Segments of a pollinator community may facilitate gynodioecy by selecting for plant characteristics that increase the attractiveness of both sexes to pollinators, such as nectar rewards. Conversely, discriminating visitors in search of pollen may restrict gynodioecy in associated plant lineages by reducing male steriles' fitness below threshold levels.

Publisher's Note: JLab Measurements of the

This corrects the article DOI: 10.1103/PhysRevLett.119.162501.