γδ T Cells Mediate Protection Against Neutrophil-associated Lung Inflammation in Pulmonary Melioidosis.

Pulmonary melioidosis is a severe tropical infection caused by Burkholderia pseudomallei and is associated with high mortality despite early antibiotic treatment. γδ T cells have been increasingly implicated as drivers of the host neutrophil response during bacterial pneumonia, but their role in pulmonary melioidosis is unknown. Here, we report that in patients with melioidosis, a lower peripheral blood γδ T cell concentration is associated with higher mortality even when adjusting for severity of illness. γδ T cells were also enriched in the lung and protected against mortality in a mouse model of pulmonary melioidosis. γδ T cell deficiency in infected mice induced an early recruitment of neutrophils to the lung, independent of bacterial burden. Subsequently, γδ T cell deficiency resulted in increased neutrophil-associated inflammation in the lung as well as impaired bacterial clearance. Additionally, γδ T cells influenced neutrophil function and subset diversity in the lung after infection. Our results indicate that γδ T cells serve a novel protective role in the lung during a severe bacterial pneumonia by regulating excessive neutrophil-associated inflammation.

Who is Represented in the Research on Undergraduate Research Experiences in the Natural Sciences? A Review of Literature.

Positive outcomes from undergraduate research experiences (UREs) have resulted in calls to broaden and diversify participation in research. However, we have little understanding of what demographics are reported and considered in the analyses of student outcomes from UREs. Without this information, it is impossible to assess whether participation in UREs has been diversified and how outcomes may vary by participant identity. Through a comprehensive literature search, we systematically identified 147 peer-reviewed research articles on student participation in UREs in the natural sciences, published between 2014 and 2020. We coded each paper to document which student demographic variables are reported and considered in analyses. The majority (88%) of articles on UREs reported at least one demographic variable and 62% incorporate demographics into their analyses, but demographics beyond gender and race/ethnicity were infrequently considered. Articles on independent research apprenticeships included demographics in their analyses more frequently than studies on course-based undergraduate research experiences (CUREs). Trends in reporting and analyzing demographics did not change from 2014 to 2020. Future efforts to collect these data will help assess whether goals to diversify UREs are being met and inform how to design UREs to meet the needs of diverse student groups.

Prognostic Accuracy of Screening Tools for Clinical Deterioration in Adults With Suspected Sepsis in Northeastern Thailand: A Cohort Validation Study.

Background: We sought to assess the performance of commonly used clinical scoring systems to predict imminent clinical deterioration in patients hospitalized with suspected infection in rural Thailand. Methods: Patients with suspected infection were prospectively enrolled within 24 hours of admission to a referral hospital in northeastern Thailand between 2013 and 2017. In patients not requiring intensive medical interventions, multiple enrollment scores were calculated including the National Early Warning Score (NEWS), the Modified Early Warning Score, Between the Flags, and the quick Sequential Organ Failure Assessment score. Scores were tested for predictive accuracy of clinical deterioration, defined as a new requirement of mechanical ventilation, vasoactive medications, intensive care unit admission, and/or death approximately 1 day after enrollment. The association of each score with clinical deterioration was evaluated by means of logistic regression, and discrimination was assessed by generating area under the receiver operating characteristic curve. Results: Of 4989 enrolled patients, 2680 met criteria for secondary analysis, and 100 of 2680 (4%) experienced clinical deterioration within 1 day after enrollment. NEWS had the highest discrimination for predicting clinical deterioration (area under the receiver operating characteristic curve, 0.78 [95% confidence interval, .74-.83]) compared with the Modified Early Warning Score (0.67 [.63-.73]; P < .001), quick Sequential Organ Failure Assessment (0.65 [.60-.70]; P < .001), and Between the Flags (0.69 [.64-.75]; P < .001). NEWS ≥5 yielded optimal sensitivity and specificity for clinical deterioration prediction. Conclusions: In patients hospitalized with suspected infection in a resource-limited setting in Southeast Asia, NEWS can identify patients at risk of imminent clinical deterioration with greater accuracy than other clinical scoring systems.

Lack of Association of TLR1 and TLR5 Coding Variants with Mortality in a Large Multicenter Cohort of Melioidosis Patients.

Melioidosis, infection caused by Burkholderia pseudomallei, is characterized by robust innate immune responses. We have previously reported associations of TLR1 single nucleotide missense variant rs76600635 with mortality and of TLR5 nonsense variant rs5744168 with both bacteremia and mortality in single-center studies of patients with melioidosis in northeastern Thailand. The objective of this study was to externally validate the associations of rs76600635 and rs5744168 with bacteremia and mortality in a large multicenter cohort of melioidosis patients. We genotyped rs76600635 and rs5744168 in 1,338 melioidosis patients enrolled in a prospective parent cohort study conducted at nine hospitals in northeastern Thailand. The genotype frequencies of rs76600635 did not differ by bacteremia status (P = 0.27) or 28-day mortality (P = 0.84). The genotype frequencies of rs5744168 did not differ by either bacteremia status (P = 0.46) or 28-day mortality (P = 0.10). Assuming a dominant genetic model, there was no association of the rs76600635 variant with bacteremia (adjusted odds ratio [OR], 0.75; 95% CI, 0.54-1.04, P = 0.08) or 28-day mortality (adjusted OR, 0.96; 95% CI, 0.71-1.28, P = 0.77). There was no association of the rs5744168 variant with bacteremia (adjusted OR, 1.24; 95% CI, 0.76-2.03, P = 0.39) or 28-day mortality (adjusted OR, 1.22; 95% CI, 0.83-1.79, P = 0.21). There was also no association of either variant with 1-year mortality. We conclude that in a large multicenter cohort of patients hospitalized with melioidosis in northeastern Thailand, neither TLR1 missense variant rs76600635 nor TLR5 nonsense variant rs5744168 is associated with bacteremia or mortality.

Statin Use and Reduced Risk of Pneumonia in Patients with Melioidosis: A Lung-Specific Statin Association.

Rationale: 3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) use is associated with a lower risk of incident pneumonia and, less robustly, with nonpulmonary infections. Whether statin use is associated with a lower risk of pneumonia than other clinical presentations of infection with the same pathogen is unknown. Objectives: To assess whether preadmission statin use is associated with a lower risk of pneumonia than nonpneumonia presentations among patients hospitalized with Burkholderia pseudomallei infection (melioidosis). Methods: We performed a secondary analysis of a prospective multicenter cohort study of patients hospitalized with culture-confirmed B. pseudomallei infection (melioidosis). We used Poisson regression with robust standard errors to test for an association between statin use and pneumonia. We then performed several sensitivity analyses that addressed healthy user effect and indication bias. Results: Of 1,372 patients with melioidosis enrolled in the parent cohort, 1,121 were analyzed. Nine hundred eighty (87%) of 1,121 were statin nonusers, and 141 (13%) of 1,121 were statin users. Forty-six (33%) of 141 statin users presented with pneumonia compared with 432 (44%) of 980 statin nonusers. Statin use was associated with a lower risk of pneumonia in unadjusted analysis (relative risk, 0.74; 95% confidence interval, 0.58-0.95; P = 0.02) and, after adjustment for demographic variables, comorbidities, environmental exposures, and symptom duration (relative risk, 0.73; 95% confidence interval, 0.57-0.94; P = 0.02). The results of sensitivity analyses, including active comparator analysis and inverse probability of treatment weighting, were consistent with the primary analysis. Conclusions: In hospitalized patients with melioidosis, preadmission statin use was associated with a lower risk of pneumonia than other clinical presentations of melioidosis, suggesting a lung-specific protective effect of statins.

IL-1R2-based biomarker models predict melioidosis mortality independent of clinical data.

Introduction: Melioidosis is an often-fatal tropical infectious disease caused by the Gram-negative bacillus Burkholderia pseudomallei, but few studies have identified promising biomarker candidates to predict outcome. Methods: In 78 prospectively enrolled patients hospitalized with melioidosis, six candidate protein biomarkers, identified from the literature, were measured in plasma at enrollment. A multi-biomarker model was developed using least absolute shrinkage and selection operator (LASSO) regression, and mortality discrimination was compared to a clinical variable model by receiver operating characteristic curve analysis. Mortality prediction was confirmed in an external validation set of 191 prospectively enrolled patients hospitalized with melioidosis. Results: LASSO regression selected IL-1R2 and soluble triggering receptor on myeloid cells 1 (sTREM-1) for inclusion in the candidate biomarker model. The areas under the receiver operating characteristic curve (AUC) for mortality discrimination for the IL-1R2 + sTREM-1 model (AUC 0.81, 95% CI 0.72-0.91) as well as for an IL-1R2-only model (AUC 0.78, 95% CI 0.68-0.88) were higher than for a model based on a modified Sequential Organ Failure Assessment (SOFA) score (AUC 0.69, 95% CI 0.56-0.81, p < 0.01, p = 0.03, respectively). In the external validation set, the IL-1R2 + sTREM-1 model (AUC 0.86, 95% CI 0.81-0.92) had superior 28-day mortality discrimination compared to a modified SOFA model (AUC 0.80, 95% CI 0.74-0.86, p < 0.01) and was similar to a model containing IL-1R2 alone (AUC 0.82, 95% CI 0.76-0.88, p = 0.33). Conclusion: Biomarker models containing IL-1R2 had improved 28-day mortality prediction compared to clinical variable models in melioidosis and may be targets for future, rapid test development.

Enhanced bedside mortality prediction combining point-of-care lactate and the quick Sequential Organ Failure Assessment (qSOFA) score in patients hospitalised with suspected infection in southeast Asia: a cohort study.

BACKGROUND: Simple, bedside prediction of infection-related mortality in low-resource settings is crucial for triage and resource-utilisation decisions. We aimed to evaluate mortality prediction by combining point-of-care venous lactate with the quick Sequential Organ Failure Assessment (qSOFA) score in adult patients admitted to hospital with suspected infection in southeast Asia. METHODS: We performed a cohort study by prospectively enrolling patients aged 18 years or older who had been admitted to hospital within the previous 24 h for suspected infection (with at least three documented systemic manifestations of infection according to the 2012 Surviving Sepsis Campaign) at Sunpasitthiprasong Hospital in Ubon Ratchathani, Thailand (derivation cohort). Venous lactate concentration was determined by a point-of-care device and multiple scores were developed. We then evaluated candidate 28-day mortality prediction models combining qSOFA and the lactate scores. A final model was compared with the qSOFA score, a lactate score, and a modified Sequential Organ Failure Assessment (SOFA) score for mortality discrimination using the area under the receiver operating characteristic curve (AUROC). Mortality discrimination of the qSOFA-lactate score was then verified in an external, prospectively enrolled, multinational cohort in southeast Asia. FINDINGS: Between March 1, 2013, and Jan 26, 2017, 5001 patients were enrolled in the derivation cohort; 4980 had point-of-care lactate data available and were eligible for analysis, and 816 died within 28 days of enrolment. The discrimination for 28-day mortality prediction of a qSOFA-lactate score combining the qSOFA score and a lactate score was superior to that of the qSOFA score alone (AUROC 0·78 [95% CI 0·76-0·80] vs 0·68 [0·67-0·70]; p<0·0001) and similar to a modified SOFA score (0·77 [0·75-0·78]; p=0·088). A lactate score alone had superior discrimination compared with the qSOFA score (AUROC 0·76 [95% CI 0·74-0·78]; p<0·0001). 815 patients were enrolled in the external validation cohort and 792 had point-of-care lactate data and were included in the analysis; the qSOFA-lactate score (AUROC 0·77 [95% CI 0·73-0·82]) showed significantly improved 28-day mortality discrimination compared with the qSOFA score alone (0·69 [0·63-0·74]; p<0·0001). INTERPRETATION: In southeast Asia, rapid, bedside assessments based on point-of-care lactate concentration combined with the qSOFA score can identify patients at risk of sepsis-related mortality with greater accuracy than the qSOFA score alone, and with similar accuracy to a modified SOFA score. FUNDING: National Institutes of Health, Wellcome Trust.

Desmoglein-2 harnesses a PDZ-GEF2/Rap1 signaling axis to control cell spreading and focal adhesions independent of cell-cell adhesion.

Desmosomes have a central role in mediating extracellular adhesion between cells, but they also coordinate other biological processes such as proliferation, differentiation, apoptosis and migration. In particular, several lines of evidence have implicated desmosomal proteins in regulating the actin cytoskeleton and attachment to the extracellular matrix, indicating signaling crosstalk between cell-cell junctions and cell-matrix adhesions. In our study, we found that cells lacking the desmosomal cadherin Desmoglein-2 (Dsg2) displayed a significant increase in spreading area on both fibronectin and collagen, compared to control A431 cells. Intriguingly, this effect was observed in single spreading cells, indicating that Dsg2 can exert its effects on cell spreading independent of cell-cell adhesion. We hypothesized that Dsg2 may mediate cell-matrix adhesion via control of Rap1 GTPase, which is well known as a central regulator of cell spreading dynamics. We show that Rap1 activity is elevated in Dsg2 knockout cells, and that Dsg2 harnesses Rap1 and downstream TGFß signaling to influence both cell spreading and focal adhesion protein phosphorylation. Further analysis implicated the Rap GEF PDZ-GEF2 in mediating Dsg2-dependent cell spreading. These data have identified a novel role for Dsg2 in controlling cell spreading, providing insight into the mechanisms via which cadherins exert non-canonical junction-independent effects.

A 2-Biomarker Model Augments Clinical Prediction of Mortality in Melioidosis.

BACKGROUND: Melioidosis, infection caused by Burkholderia pseudomallei, is a common cause of sepsis with high associated mortality in Southeast Asia. Identification of patients at high likelihood of clinical deterioration is important for guiding decisions about resource allocation and management. We sought to develop a biomarker-based model for 28-day mortality prediction in melioidosis. METHODS: In a derivation set (N = 113) of prospectively enrolled, hospitalized Thai patients with melioidosis, we measured concentrations of interferon-γ, interleukin-1ß, interleukin-6, interleukin-8, interleukin-10, tumor necrosis factor-ɑ, granulocyte-colony stimulating factor, and interleukin-17A. We used least absolute shrinkage and selection operator (LASSO) regression to identify a subset of predictive biomarkers and performed logistic regression and receiver operating characteristic curve analysis to evaluate biomarker-based prediction of 28-day mortality compared with clinical variables. We repeated select analyses in an internal validation set (N = 78) and in a prospectively enrolled external validation set (N = 161) of hospitalized adults with melioidosis. RESULTS: All 8 cytokines were positively associated with 28-day mortality. Of these, interleukin-6 and interleukin-8 were selected by LASSO regression. A model consisting of interleukin-6, interleukin-8, and clinical variables significantly improved 28-day mortality prediction over a model of only clinical variables [AUC (95% confidence interval [CI]): 0.86 (.79-.92) vs 0.78 (.69-.87); P = .01]. In both the internal validation set (0.91 [0.84-0.97]) and the external validation set (0.81 [0.74-0.88]), the combined model including biomarkers significantly improved 28-day mortality prediction over a model limited to clinical variables. CONCLUSIONS: A 2-biomarker model augments clinical prediction of 28-day mortality in melioidosis.

Importance of van der Waals interactions forab initiostudies of topological insulators.

We investigate the lattice and electronic structures of the bulk and surface of the prototypical layered topological insulators Bi2Se3and Bi2Te3usingab initiodensity functional methods, and systematically compare the results of different methods of including van der Waals (vdW) interactions. We show that the methods utilizing semi-empirical energy corrections yield accurate descriptions of these materials, with the most precise results obtained by properly accounting for the long-range tail of the vdW interactions. The bulk lattice constants, distances between quintuple layers and the Dirac velocity of the topological surface states (TSS) are all in excellent agreement with experiment. In Bi2Te3, hexagonal warping of the energy dispersion leads to complex spin textures of the TSS at moderate energies, while in Bi2Se3these states remain almost perfectly helical away from the Dirac point, showing appreciable signs of hexagonal warping at much higher energies, above the minimum of the bulk conduction band. Our results establish a framework for unified and systematic self-consistent first principles calculations of topological insulators in bulk, slab and interface geometries, and provides the necessary first step towardab initiomodeling of topological heterostructures.

Lactoferrin is a dynamic protein in human melioidosis and is a TLR4-dependent driver of TNF-α release in Burkholderia thailandensis infection in vitro.

Melioidosis is an often-severe tropical infection caused by Burkholderia pseudomallei (Bp) with high associated morbidity and mortality. Burkholderia thailandensis (Bt) is a closely related surrogate that does not require BSL-3 conditions for study. Lactoferrin is an iron-binding glycoprotein that can modulate the innate inflammatory response. Here we investigated the impact of lactoferrin on the host immune response in melioidosis. Lactoferrin concentrations were measured in plasma from patients with melioidosis and following ex vivo stimulation of blood from healthy individuals. Bt growth was quantified in liquid media in the presence of purified and recombinant human lactoferrin. Differentiated THP-1 cells and human blood monocytes were infected with Bt in the presence of purified and recombinant human lactoferrin, and bacterial intracellular replication and cytokine responses (tumor necrosis factor-α (TNF-α), interleukin-1ß and interferon-γ) were measured. In a cohort of 49 melioidosis patients, non-survivors to 28 days had significantly higher plasma lactoferrin concentrations compared to survivors (median (interquartile range (IQR)): 326 ng/ml (230-748) vs 144 ng/ml (99-277), p<0.001). In blood stimulated with heat-killed Bp, plasma lactoferrin concentration significantly increased compared to unstimulated blood (median (IQR): 424 ng/ml (349-479) vs 130 ng/ml (91-214), respectively; p<0.001). Neither purified nor recombinant human lactoferrin impaired growth of Bt in media. Lactoferrin significantly increased TNF-α production by differentiated THP-1 cells and blood monocytes after Bt infection. This phenotype was largely abrogated when Toll-like receptor 4 (TLR4) was blocked with a monoclonal antibody. In sum, lactoferrin is produced by blood cells after exposure to Bp and lactoferrin concentrations are higher in 28-day survivors in melioidosis. Lactoferrin induces proinflammatory cytokine production after Bt infection that may be TLR4 dependent.

sTREM-1 predicts mortality in hospitalized patients with infection in a tropical, middle-income country.

BACKGROUND: Few studies of biomarkers as predictors of outcome in infection have been performed in tropical, low- and middle-income countries where the burden of sepsis is highest. We evaluated whether selected biomarkers could predict 28-day mortality in infected patients in rural Thailand. METHODS: Four thousand nine hundred eighty-nine adult patients admitted with suspected infection to a referral hospital in northeast Thailand were prospectively enrolled within 24 h of admission. In a secondary analysis of 760 patients, interleukin-8 (IL-8), soluble tumor necrosis factor receptor 1 (sTNFR-1), angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), and soluble triggering receptor expressed by myeloid cells 1 (sTREM-1) were measured in the plasma. Association with 28-day mortality was evaluated using regression; a parsimonious biomarker model was selected using the least absolute shrinkage and selection operator (LASSO) method. Discrimination of mortality was assessed by receiver operating characteristic curve analysis and verified by multiple methods. RESULTS: IL-8, sTNFR-1, Ang-2, and sTREM-1 concentrations were strongly associated with death. LASSO identified a three-biomarker model of sTREM-1, Ang-2, and IL-8, but sTREM-1 alone provided comparable mortality discrimination (p = 0.07). sTREM-1 alone was comparable to a model of clinical variables (area under receiver operating characteristic curve [AUC] 0.81, 95% confidence interval [CI] 0.77-0.85 vs AUC 0.79, 95% CI 0.74-0.84; p = 0.43). The combination of sTREM-1 and clinical variables yielded greater mortality discrimination than clinical variables alone (AUC 0.83, 95% CI 0.79-0.87; p = 0.004). CONCLUSIONS: sTREM-1 predicts mortality from infection in a tropical, middle-income country comparably to a model derived from clinical variables and, when combined with clinical variables, can further augment mortality prediction. TRIAL REGISTRATION: The Ubon-sepsis study was registered on ClinicalTrials.gov ( NCT02217592 ), 2014.

Exonic sequencing identifies TLR1 genetic variation associated with mortality in Thais with melioidosis.

Melioidosis, an infectious disease caused by the bacterium Burkholderia pseudomallei, is a common cause of sepsis in Southeast Asia. We investigated whether novel TLR1 coding variants are associated with outcome in Thai patients with melioidosis. We performed exonic sequencing on a discovery set of patients with extreme phenotypes (mild vs. severe) of bacteremic melioidosis. We analysed the association of missense variants in TLR1 with severe melioidosis in a by-gene analysis. We then genotyped key variants and tested the association with death in two additional sets of melioidosis patients. Using a by-gene analysis, TLR1 was associated with severe bacteremic melioidosis (P = 0.016). One of the eight TLR1 variants identified, rs76600635, a common variant in East Asians, was associated with in-hospital mortality in a replication set of melioidosis patients (adjusted odds ratio 1.71, 95% CI 1.01-2.88, P = 0.04.) In a validation set of patients, the point estimate of effect of the association of rs76600635 with 28-day mortality was similar but not statistically significant (adjusted odds ratio 1.81, 95% CI 0.96-3.44, P = 0.07). Restricting the validation set analysis to patients recruited in a comparable fashion to the discovery and replication sets, rs76600635 was significantly associated with 28-day mortality (adjusted odds ratio 3.88, 95% CI 1.43-10.56, P = 0.01). Exonic sequencing identifies TLR1 as a gene associated with a severe phenotype of bacteremic melioidosis. The TLR1 variant rs76600635, common in East Asian populations, may be associated with poor outcomes from melioidosis. This variant has not been previously associated with outcomes in sepsis and requires further study.

Spin density wave instability in a ferromagnet.

Due to its cooperative nature, magnetic ordering involves a complex interplay between spin, charge, and lattice degrees of freedom, which can lead to strong competition between magnetic states. Binary Fe3Ga4 is one such material that exhibits competing orders having a ferromagnetic (FM) ground state, an antiferromagnetic (AFM) behavior at intermediate temperatures, and a conspicuous re-entrance of the FM state at high temperature. Through a combination of neutron diffraction experiments and simulations, we have discovered that the AFM state is an incommensurate spin-density wave (ISDW) ordering generated by nesting in the spin polarized Fermi surface. These two magnetic states, FM and ISDW, are seldom observed in the same material without application of a polarizing magnetic field. To date, this unusual mechanism has never been observed and its elemental origins could have far reaching implications in many other magnetic systems that contain strong competition between these types of magnetic order. Furthermore, the competition between magnetic states results in a susceptibility to external perturbations allowing the magnetic transitions in Fe3Ga4 to be controlled via temperature, magnetic field, disorder, and pressure. Thus, Fe3Ga4 has potential for application in novel magnetic memory devices, such as the magnetic components of tunneling magnetoresistance spintronics devices.

Nontrivial Berry phase in magnetic BaMnSb2 semimetal.

The subject of topological materials has attracted immense attention in condensed-matter physics because they host new quantum states of matter containing Dirac, Majorana, or Weyl fermions. Although Majorana fermions can only exist on the surface of topological superconductors, Dirac and Weyl fermions can be realized in both 2D and 3D materials. The latter are semimetals with Dirac/Weyl cones either not tilted (type I) or tilted (type II). Although both Dirac and Weyl fermions have massless nature with the nontrivial Berry phase, the formation of Weyl fermions in 3D semimetals require either time-reversal or inversion symmetry breaking to lift degeneracy at Dirac points. Here we demonstrate experimentally that canted antiferromagnetic BaMnSb2 is a 3D Weyl semimetal with a 2D electronic structure. The Shubnikov-de Hass oscillations of the magnetoresistance give nearly zero effective mass with high mobility and the nontrivial Berry phase. The ordered magnetic arrangement (ferromagnetic ordering in the ab plane and antiferromagnetic ordering along the c axis below 286 K) breaks the time-reversal symmetry, thus offering us an ideal platform to study magnetic Weyl fermions in a centrosymmetric material.

Conduct, Oversight, and Ethical Considerations of Clinical Trials in Companion Animals with Cancer: Report of a Workshop on Best Practice Recommendations.

Development of effective and safe treatments for companion animals with cancer requires the collaboration of numerous animal health professionals and the full engagement of animal owners. Establishing 'Best Practice Recommendations' for clinical trials in veterinary oncology represents an important step toward meeting the goal of rigorous clinical trial design and conduct that is required to establish valid evidence. Likewise, optimizing patient welfare and owner education and advocacy is crucial to meet the unique ethical obligations to both owners and animals enrolled in these clinical trials and to ensure trust in the team conducting the research. To date, 'Best Practice Recommendations' for clinical trial conduct have not been reported for veterinary oncology. This document summarizes the consensus of a workshop held in November, 2014 to identify relevant ethical principles and to ensure responsible conduct of clinical research in companion animals with cancer. It is intended as a working document that will be updated as advances in science and ethical considerations require. To the extent possible, existing guidelines for the conduct and oversight of clinical trials in humans have been adapted for veterinary trials to avoid duplicative effort and to facilitate integration of clinical trials such that translational research with benefits for both companion animals and humans are encouraged.

Effects of Temperature on In Vitro Short-Term Storage of Sterlet Sturgeon (Acipenser Ruthenus) Ova.

Artificial propagation of sturgeons is becoming increasingly important for recovery efforts as well as for commercial production. Sterlet Acipenser ruthenus is a common Eurasian sturgeon with a small body size and one of the fastest reproductive cycles among the sturgeons. The practical question being addressed in this study was how long fertilization of ovulated eggs can be delayed without substantially reducing the hatching rate, and an ancillary question is under what' temperature conditions do eggs retain good quality. Broodstock were injected with homogenized carp pituitary extract (CPE); ovulated eggs from three females were allocated to various treatment groups for temperature storage (control, 7°C, 11°C, 15°C and 19°C) until fertilized. Storage times at the regulated temperatures prior to fertilization were for 2.5, 5.0, 7.5 and 10.0 h. After the selected storage times in ovarian fluid, eggs were fertilized and transferred to incubation cages and then they were counted. Three replicates were allocated to each storage period and temperature. Hatched larvae were counted at 7-day post-fertilization. We found that sterlet eggs do not need to be fertilized immediately after collection. Reasonably good quality was retained for several hours if temperature conditions are fairly cool and stable. Eggs retained good quality when stored at 7°C and 11°C for up to 10 h with 54.1 ± 2.9 to 69.9 ± 7.9% hatching success, but egg quality was significantly reduced after 5-h storage at 19°C (p < 0.01) and 7.5-h storage at 15°C (p < 0.05) compared to cooler temperatures. Uniform temperatures between 7°C and 11°C can be considered as appropriate for storage of eggs in ovarian fluid for up to 10 h. This information can have practical application to routine hatchery practice for acipenserids, as well as for certain research protocols.

Impact of contextualized pediatric resuscitation training on pediatric healthcare providers in Botswana.

BACKGROUND: Worldwide, 6.6 million children die each year, partly due to a failure to recognize and treat acutely ill children. Programs that improve provider recognition and treatment initiation may improve child survival. OBJECTIVES: Describe provider characteristics and hospital resources during a contextualized pediatric resuscitation training program in Botswana and determine if training impacts provider knowledge retention. DESIGN/METHODS: The American Heart Association's Pediatric Emergency Assessment Recognition and Stabilization (PEARS) course was contextualized to Botswana resources and practice guidelines in this observational study. A cohort of facility-based nurses (FBN) was assessed prior to and 1-month following training. Survey tools assessed provider characteristics, cognitive knowledge and confidence and hospital pediatric resources. Data analysis utilized Fisher's exact, Chi-square, Wilcoxon rank-sum and linear regression where appropriate. RESULTS: 61 healthcare providers (89% FBNs, 11% physicians) successfully completed PEARS training. Referral facilities had more pediatric specific equipment and high-flow oxygen. Median frequency of pediatric resuscitation was higher in referral compared to district level FBN's (5 [3,10] vs. 2 [1,3] p=0.007). While 50% of FBN's had previous resuscitation training, none was pediatric specific. Median provider confidence improved significantly after training (3.8/5 vs. 4.7/5, p<0.001), as did knowledge of correct management of acute pneumonia and diarrhea (44% vs. 100%, p<0.001, 6% vs. 67%, p<0.001, respectively). CONCLUSION: FBN's in Botswana report frequent resuscitation of ill children but low baseline training. Provider knowledge for recognition and initial treatment of respiratory distress and shock is low. Contextualized training significantly increased FBN provider confidence and knowledge retention 1-month after training.

Coupled-cluster representation of Green function employing modified spectral resolutions of similarity transformed Hamiltonians.

In this paper we discuss a new formalism for producing an analytic coupled-cluster (CC) Green's function for an N-electron system by shifting the poles of similarity transformed Hamiltonians represented in N - 1 and N + 1 electron Hilbert spaces. Simple criteria are derived for the states in N - 1 and N + 1 electron spaces that are then corrected in the spectral resolution of the corresponding matrix representations of the similarity transformed Hamiltonian. The accurate description of excited state processes within a Green's function formalism would be of significant importance to a number of scientific communities ranging from physics and chemistry to engineering and the biological sciences. This is because the Green's function methodology provides a direct path for not only calculating properties whose underlying origins come from coupled many-body interactions but also provides a straightforward path for calculating electron transport, response, and correlation functions that allows for a direct link with experiment. As a special case of this general formulation, we discuss the application of this technique for Green's function defined by the CC with singles and doubles representation of the ground-state wave function.

Prenatal, perinatal, and neonatal risk factors for specific language impairment: a prospective pregnancy cohort study.

PURPOSE: Although genetic factors are known to play a causal role in specific language impairment (SLI), environmental factors may also be important. This study examined whether there are prenatal, perinatal, and neonatal factors that are associated with childhood SLI. METHOD: Participants were members of the Raine Study, a prospective cohort investigation of pregnant women and their offspring. Parent report indicated that 26 children had received a clinical diagnosis of SLI. Data from antenatal and birth medical records were compared between the children with SLI and typically developing comparison children (N = 1,799). RESULTS: There were no statistically significant differences between the SLI and comparison groups in the individual prenatal, perinatal, and neonatal factors examined. Aggregate risk scores were calculated for each period on the basis of factors known to be associated with neurodevelopmental disorder. There were no group differences in aggregate risk scores in the prenatal and perinatal periods. However, significantly more children in the SLI group (50%) compared with the comparison group (27.6%) experienced 2 or more risk factors during the neonatal period. CONCLUSION: The vast majority of prenatal, perinatal, and neonatal complications do not play a clear causal role in childhood SLI. However, poor neonatal health may signify increased risk for SLI.