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Medical Procedure Services (MPS) may represent a solution to the educational gap in procedural training among internal medicine residents and the unmet need for the clinical provision of non-urgent inpatient procedures. However, there is little guidance available to help launch an MPS. Furthermore, procedural outcomes from a newly initiated MPS, including those comparing trainees versus attending physicians, are lacking.To describe the blueprint used in the design, implementation, and ongoing oversight of an MPS and to report its procedural outcomes.Vanderbilt University Medical Center (VUMC), Nashville, Tennessee.The launch of an MPS at a large tertiary academic hospital.6,152 procedural consultations resulting in 5,320 attempted procedures over a four-and-a-half year period.The primary proceduralist was a supervised resident in 58.7% (3124 /5,320) and an attending in 41.3% (2,196/5,320) of procedures. The overall success rate was 91.1% (95% CI: 90.3-91.9%) and the major complication rate was 0.7% (95% CI: 0.5-1.0%). There was no difference in the mean number of attempts required to complete a procedure (1.6 vs 1.5 attempts, p=0.68) and the complication rates between supervised residents and attending proceduralists, respectively (20/3,124 vs 20/2,196, p=0.26).At a tertiary academic medical center, the implementation and maintenance of MPS is feasible, safe, and results in high rates of successful procedures performed by supervised residents. Procedures performed by supervised residents require comparable number of attempts for completion and carry similar risks as those performed alone by attendings.

Introduction A quarter of newly diagnosed bladder cancers are muscle-invasive (MIBC) (45% 5-year disease free survival). 30% patients with apparent non-muscle-invasive cancer (NMIBC) have MIBC on histology following cystectomy (RARC). Tumour associated macrophages (TAMs) polarise into an immunogenic M1 phenotype or immunosuppressive M2 phenotype. This study assesses accuracy and validity of quantifying urinary macrophages for earlier recognition of treatment resistant bladder cancer. Methods Urine-derived cells and tumour and adjacent normal bladder derived cells were collected from 18 RARC patients between May-October 2022. Flow cytometry performed for immune cell profiling (MACSQuant). Results The urinary immune cell profile closely reflected the tumour immune profile. Females had higher CD206+CD163+ M2 phenotype cells in urine and in tumour (p Conclusion The TAM immune cell profile is reflected accurately in urine sampled at RARC: a higher proportion of M2 phenotypic macrophages and lower proportion of M1 macrophages in the tumour and urine is predictive of more aggressive disease. This study highlights the potential application of urinary derived TAM analysis for disease outcome prediction and early consideration of adjuvant immune checkpoint therapy.

Background and aim Organoids are 3D models that retain the architecture and function of the organ from which they are derived. Culture of oesophageal adenocarcinoma organoids from individual’s standard endoscopic biopsies to assess response to therapy could dramatically alter the neo-adjuvant treatment paradigm, giving clarity over who will benefit from preoperative therapy, including novel treatment methodologies. Immune checkpoint blockade (ICB) has been shown to be effective in oesophageal adenocarcinoma. Combining Oncolytic Virotherapy with ICB could enhance the action of ICB alone, through selective infection of tumour cells accompanied by immunogenic cell death, with release of neo-tumour antigens and alteration of the tumour microenvironment. Methods This study uses organoids derived from endoscopic biopsies to assess the viability of an oncolytic herpes simplex virus in the treatment of oesophageal adenocarcinoma. Samples were taken at routine staging endoscopy using standard biopsy forceps. Tissue specimens were dissociated using the Miltenyi tumour dissociation kit before being suspended in Matrigel in Oesophageal adenocarcinoma conditioned media. Media was changed every 48 hours with domes being split every 7–10 days. After >6 passages organoids were incubated with an oncolytic herpes simplex virus lacking ICP 34.5 and 47. Growth was monitored, and green fluorescence protein expression measured using the Incucyte SX5 Live Cell Analysis system. Results Organoids were successfully established and cultured beyond 6 passages for patients with oesophageal adenocarcinoma. Organoids incubated with an oncolytic herpes simplex virus demonstrated significantly reduced growth compared to untreated organoids with increased expression of green fluorescence protein indicating viral infection. Conclusion We have demonstrated a successful methodology to culture Oesophageal adenocarcinoma organoids from endoscopic biopsies. Further work to determine their responses to standard chemotherapy used in the perioperative phase will help to assess their potential for providing bespoke therapy in the future. Oncolytic herpes simplex virus is able to infect and cause lysis of OAC organoids supporting its potential use in driving an increased inflammatory tumour microenvironment which could be combined with immune checkpoint blockade to induce durable responses for patients.

Importance: Understanding of SARS-CoV-2 infection in US children has been limited by the lack of large, multicenter studies with granular data. Objective: To examine the characteristics, changes over time, outcomes, and severity risk factors of children with SARS-CoV-2 within the National COVID Cohort Collaborative (N3C). Design, Setting, and Participants: A prospective cohort study of encounters with end dates before September 24, 2021, was conducted at 56 N3C facilities throughout the US. Participants included children younger than 19 years at initial SARS-CoV-2 testing. Main Outcomes and Measures: Case incidence and severity over time, demographic and comorbidity severity risk factors, vital sign and laboratory trajectories, clinical outcomes, and acute COVID-19 vs multisystem inflammatory syndrome in children (MIS-C), and Delta vs pre-Delta variant differences for children with SARS-CoV-2. Results: A total of 1068410 children were tested for SARS-CoV-2 and 167262 test results (15.6%) were positive (82882 [49.6%] girls; median age, 11.9 [IQR, 6.0-16.1] years). Among the 10245 children (6.1%) who were hospitalized, 1423 (13.9%) met the criteria for severe disease: mechanical ventilation (796 [7.8%]), vasopressor-inotropic support (868 [8.5%]), extracorporeal membrane oxygenation (42 [0.4%]), or death (131 [1.3%]). Male sex (odds ratio [OR], 1.37; 95% CI, 1.21-1.56), Black/African American race (OR, 1.25; 95% CI, 1.06-1.47), obesity (OR, 1.19; 95% CI, 1.01-1.41), and several pediatric complex chronic condition (PCCC) subcategories were associated with higher severity disease. Vital signs and many laboratory test values from the day of admission were predictive of peak disease severity. Variables associated with increased odds for MIS-C vs acute COVID-19 included male sex (OR, 1.59; 95% CI, 1.33-1.90), Black/African American race (OR, 1.44; 95% CI, 1.17-1.77), younger than 12 years (OR, 1.81; 95% CI, 1.51-2.18), obesity (OR, 1.76; 95% CI, 1.40-2.22), and not having a pediatric complex chronic condition (OR, 0.72; 95% CI, 0.65-0.80). The children with MIS-C had a more inflammatory laboratory profile and severe clinical phenotype, with higher rates of invasive ventilation (117 of 707 [16.5%] vs 514 of 8241 [6.2%]; P

ImportanceSARS-CoV-2ObjectiveTo determine the characteristics, changes over time, outcomes, and severity risk factors of SARS-CoV-2 affected children within the National COVID Cohort Collaborative (N3C)DesignProspective cohort study of patient encounters with end dates before May 27th, 2021.Setting45 N3C institutionsParticipantsChildren Main Outcomes and MeasuresCase incidence and severity over time, demographic and comorbidity severity risk factors, vital sign and laboratory trajectories, clinical outcomes, and acute COVID-19 vs MIS-C contrasts for children infected with SARS-CoV-2.Results728,047 children in the N3C were tested for SARS-CoV-2; of these, 91,865 (12.6%) were positive. Among the 5,213 (6%) hospitalized children, 685 (13%) met criteria for severe disease: mechanical ventilation (7%), vasopressor/inotropic support (7%), ECMO (0.6%), or death/discharge to hospice (1.1%). Male gender, African American race, older age, and several pediatric complex chronic condition (PCCC) subcategories were associated with higher clinical severity (p≤0.05). Vital signs (all p≤0.002) and many laboratory tests from the first day of hospitalization were predictive of peak disease severity. Children with severe (vs moderate) disease were more likely to receive antimicrobials (71% vs 32%, pCompared to those with acute COVID-19, children with MIS-C were more likely to be male, Black/African American, 1-to-12-years-old, and less likely to have asthma, diabetes, or a PCCC (p<0.04). MIS-C cases demonstrated a more inflammatory laboratory profile and more severe clinical phenotype with higher rates of invasive ventilation (12% vs 6%) and need for vasoactive-inotropic support (31% vs 6%) compared to acute COVID-19 cases, respectively (pConclusionsIn the largest U.S. SARS-CoV-2-positive pediatric cohort to date, we observed differences in demographics, pre-existing comorbidities, and initial vital sign and laboratory test values between severity subgroups. Taken together, these results suggest that early identification of children likely to progress to severe disease could be achieved using readily available data elements from the day of admission. Further work is needed to translate this knowledge into improved outcomes.

BackgroundThe majority of U.S. reports of COVID-19 clinical characteristics, disease course, and treatments are from single health systems or focused on one domain. Here we report the creation of the National COVID Cohort Collaborative (N3C), a centralized, harmonized, high-granularity electronic health record repository that is the largest, most representative U.S. cohort of COVID-19 cases and controls to date. This multi-center dataset supports robust evidence-based development of predictive and diagnostic tools and informs critical care and policy.Methods and FindingsIn a retrospective cohort study of 1,926,526 patients from 34 medical centers nationwide, we stratified patients using a World Health Organization COVID-19 severity scale and demographics; we then evaluated differences between groups over time using multivariable logistic regression. We established vital signs and laboratory values among COVID-19 patients with different severities, providing the foundation for predictive analytics. The cohort included 174,568 adults with severe acute respiratory syndrome associated with SARS-CoV-2 (PCR >99% or antigen ConclusionsThis is the first description of an ongoing longitudinal observational study of patients seen in diverse clinical settings and geographical regions and is the largest COVID-19 cohort in the United States. Such data are the foundation for ML models that can be the basis for generalizable clinical decision support tools. The N3C Data Enclave is unique in providing transparent, reproducible, easily shared, versioned, and fully auditable data and analytic provenance for national-scale patient-level EHR data. The N3C is built for intensive ML analyses by academic, industry, and citizen scientists internationally. Many observational correlations can inform trial designs and care guidelines for this new disease.

Objectives Renal biopsy is the gold standard for the diagnosis of both native and allograft renal diseases. We studied the impact of tissue procurement at bedside (TPB) omission on the adequacy of renal biopsies. Methods We compared 120 renal biopsies collected during 2015 using TPB with 111 renal biopsies collected during 2016 when TPB was discontinued. Adequacy criteria were applied as follows: by light microscopy, 10 glomeruli and two arteries for allograft biopsies and seven glomeruli for native biopsies. At least one glomerulus was considered adequate for immunofluorescence and electron microscopy in both groups. Results The rate of inadequacies in allograft biopsies increased significantly, from 12.50% to 21.61% (P < .05), when TPB was discontinued. Conclusions Elimination of TPB service had a negative impact on allograft specimen adequacy. Repeat biopsies add cost and delay patient care. Institutions should take this into consideration when considering omission of TPB.

According to Poloma and Pendleton's (J Psychol Theol 19:71-83, 1991) prayer model, there are four prayer types (colloquial, meditative, petitionary, and ritual), all of which have varying associations with mental health. However, few studies have examined what mechanisms explain these associations. The literature demonstrates that disclosing distressing information can improve mental health. Thus, the current study examined self-disclosure as a mediating variable between Poloma and Pendleton's (J Psychol Theol 19:71-83, 1991) prayer types and mental health. It was hypothesized that self-disclosure would mediate the association between prayer types involving meaningful communication with God (colloquial and meditative prayer types) and mental health and would not mediate associations between petitionary and ritual prayer types and mental health. This cross-sectional, online study analyzed data from praying Christian adults (N = 296) to test the hypotheses. As predicted, self-disclosure mediated the positive associations between colloquial and meditative prayer types and mental health. Self-disclosure was not associated with petitionary or ritual prayer and therefore did not mediate the relationships of these prayer types with mental health, as expected. Petitionary prayer had a negative relationship to mental health, while ritual prayer had a positive relationship to mental health. The results indicate that self-disclosure is an important mediator to consider when investigating the associations between private prayer and mental health.

The recent data suggest that there has been a steady increase in the prevalence of autism spectrum disorders (ASD; Centers for Disease Control, 2012). This lifelong disorder has significant implications for families as they face the complexities of supporting their family members with ASD. Fortunately, the research literature suggests that families can benefit from training and access to parent-focused resources. The purpose of this paper is to describe a model used by one university-based autism center to establish systems of support for families of persons with ASD.Keywords: Autism Spectrum Disorders, family support, parent training, parent resourcesAutism spectrum disorders (ASD) are characterized by significant impairments in social and communicative functioning that are pervasive across environmental domains and present across the lifespan (American Psychiatric Association, 2001). Furthermore, individuals with ASD may engage in stereotyped, repetitive behaviors and exhibit a restricted range of interests, limiting parents' and professionals' opportunities to capitalize on typical motivators during daily interaction. Data suggest that the prevalence of ASD is steadily increasing and that millions of people are impacted worldwide. For example, the Centers for Disease Control (2012) recently released data suggesting that the prevalence rates in the United States have risen from 1 in 153 children in 2002 to 1 in 88 in 2012. Competing research teams have espoused theories for this rapid increase, but, to date, the research community has not come to consensus around a single culpable variable (Eagle, 2004; Landrigan, 2010).Among the persons impacted by autism are the families charged with the provision of care for their children with ASD. Researchers have demonstrated that, compared to parents of typically developing children, parents of children with ASD consistently report higher levels of stress, depression, and anxiety (Montes &. Halterman, 2008; Rao &. Beidel, 2009). Parents have suggested that having a child with ASD often results in significant adjustments to family life, including an increased strain on marital relationships, less time to engage in family activities, and having to give up on family outings and vacations (DeGrace, 2004; Hutton & Caron, 2005). These challenges associated with family adjustment are exacerbated by difficulties in accessing childcare or appropriate treatment services and balancing the demands of child care while meeting the expectations of employment (Gray, 1994; Montes &. Halterman, 2008).Fortunately, data suggest that not all families are impacted equally and that some report positive outcomes related to having a child with ASD (Hastings & Taunt, 2002). For example, Beat (2007) reported that 62% of families surveyed indicated that their family grew closer as a result of having a child with ASD. Families also reported that having a family member with ASD helped them become more compassionate, less selfish, and mindful of individual differences. These data paint an optimistic picture for families affected by a diagnosis of autism, and, fortunately, researchers have identified several factors that may contribute to positive family adjustment. Some of these factors include access to social supports (Twoy, Connolly, & Novak, 2007), having a perceived internal locus of control (Dunn, Burbine, Bowers, &. Tuntleff-Dunn, 2001), and parent training (Tonge et al., 2006).The consideration of these factors is critical in building systems of support for families of individuals with ASD. Programs and resources should be directed at fostering relationships between families and facilitating access to community supports, services, and parental training across multiple areas (e.g., navigating mental health and educational systems, intervention, transition). The purpose of this paper is to describe a model used by one university-based autism center to establish systems of support for families of persons with ASD. …

The influence of the marina canals on the lower reaches and mouth area of the Kromme estuary was investigated. Surveys were conducted during 1978 and 1979 in the marina system as well as in the main estuary in the vicinity of the marina. Analyses and comparisons of the biotic communities in the marina and in the main estuary showed a very similar composition, but differences in density were observed for several of the species. The plankton and nekton samples in the estuary and in the marina showed the same seasonal trends in abundance. The abiotic characteristics of the marina canals were also Investigated and special attention was given to water circulation in the system during a tidal cycle. These observations showed that water circulation throughout the entire system was good, indicating efficient flushing and tidal turnover. Temperature, salinity and dissolved 02 values indicated well-mixed and saturated waters. It is concluded that the marina has, in effect, increased the habitat area for plankton, benthic macro-invertebrate fauna and fish and that it does not have an adverse effect on the ecology of the Kromme estuary.

Data from an ecological survey of three sandy beaches in Transkei and from Gulu beach on the eastern Cape coast, South Africa, are presented. Physical parameters such as beach profile, sand particle size, Eh and carbonate content, as well as abundance, composition, biomass and distribution of the macrofauna and meiofauna were investigated. Beaches in Transkei are relatively small and are usually associated with estuarine systems. Substrate at Thompson's beach in northern Transkei was relatively coarse with relatively few macrofaunal species. Further south, beaches have fine to medium substrates and are characterized by a diverse macrofaunal community. Major changes in faunal composition occurred in Transkei and this was most evident for Mpande and Cebe beaches where a subtropical east-coast fauna was replaced by species characteristic of the southern Cape coast. Molluscs also became increasingly important southwards and replaced crustaceans as the most important group. Meiofauna was dominated by nematodes...

Stratification is well developed in Msikaba estuary and has a major influence on the distribution of the zooplankton. The oligohaline zooplankton component does not become well established, while marine zooplankton organisms penetrate relatively far up the estuary in the high salinity bottom waters. The euryhaline component becomes relatively well established near the mouth and it would appear that these organisms maintain their position within the estuary by vertical migration between inflowing bottom and outflowing surface waters. Seasonal means of zooplankton biomass were similar and ranged between 16 mg/m8 of water during winter and 15 mg/m8 during summer.

Systematic reviews can provide up-to-date syntheses of reliable evidence on "what works" to help policymakers, practitioners, and people who use services make well-informed decisions about social and behavioral interventions. However, systematic reviews of social and behavioral interventions do not typically include evidence on resource use and costs, critical dimensions for decision makers to consider when faced with limited resources and constrained budgets. This paper builds on existing recommendations for including evidence for resource use and costs in systematic reviews by illustrating the development and use of an instrument to code resource use and cost data from an existing systematic review on the effects of adolescent depression prevention programs and applying that instrument to 46 studies included in that review. We demonstrate that resource use and cost data are relatively sparsely reported for treatment conditions in reports of included studies and even more so for comparison conditions, although the reporting of the most important cost drivers is reasonably frequent for treatment conditions. To allow for better integration of resource use and cost data into systematic reviews, future studies that aim to inform decision making should report more detail about program resource use and costs required for implementation, perhaps using the template provided in this paper. Copyright © 2012 John Wiley & Sons, Ltd.

The UV absorption spectra of CF(3)CHO, C(2)F(5)CHO, C(3)F(7)CHO, C(4)F(9)CHO, CF(3)CH(2)CHO, and C(6)F(13)CH(2)CHO were recorded over the range 225-400 nm at 249-297 K. C(x)F(2)(x)(+1)CHO and C(x)F(2)(x)(+1)CH(2)CHO have broad absorption features centered at 300-310 and 290-300 nm, respectively. The strength of the absorption increases with the size of the C(x)F(2)(x)(+1) group. There was no discernible (

Background andobjectivesThecalcimimeticcinacalcet reduced therisk of death or cardiovascular (CV) events in older, but not younger, patients with moderate to severe secondary hyperparathyroidism (HPT) who were receiving hemodialysis. To determine whether the lower risk in younger patients might be due to lower baseline CV risk and more frequent use of cointerventions that reduce parathyroid hormone (kidney transplantation, parathyroidectomy, and commercial cinacalcet use), this study examined the effects of cinacalcet in older ($65 years, n=1005) and younger (,65 years, n=2878) patients. Design, setting, participants, & measurements Evaluation of Cinacalcet HCl Therapy to Lower Cardiovascular Events (EVOLVE) was a global, multicenter, randomized placebo-controlled trial in 3883 prevalent patients on hemodialysis, whose outcomes included death, major CV events, and development of severe unremitting HPT. The age subgroup analysis was prespecified. ResultsOlderpatients hadhigher baselineprevalenceof diabetesmellitusandCV comorbidity. Annualizedrates of kidney transplantation and parathyroidectomy were .3-fold higher in younger relative to older patients and were more frequent in patients randomized to placebo. In older patients, the adjusted relative hazard (95% confidence interval) for the primary composite (CV) end point (cinacalcet versus placebo) was 0.70 (0.60 to 0.81); in younger patients, the relative hazard was 0.97 (0.86 to 1.09). Corresponding adjusted relative hazards for mortality were 0.68 (0.51 to 0.81) and 0.99 (0.86 to 1.13). Reduction in the risk of severe unremitting HPT was similar in both groups. Conclusions In the EVOLVE trial, cinacalcet decreased the risk of death and of major CV events in older, but not younger, patients with moderate to severe HPT who were receiving hemodialysis. Effect modification by age may be partly explained by differences in underlying CV risk and differential application of cointerventions that reduce parathyroid hormone. Clin J Am Soc Nephrol 10: ccc–ccc, 2015. doi: 10.2215/CJN.07730814

Significant associations of private prayer with mental health have been found, while mechanisms underlying these associations are largely unknown. This cross-sectional online study (N = 325, age 35.74, SD 18.50, 77.5 % females) used path modeling to test if trust-based beliefs (whether, when, and how prayers are answered) mediated the associations of prayer frequency with the Anxiety, Confusion, and Depression Profile of Mood States-Short Form scales. The association of prayer and depression was fully mediated by trust-based beliefs; associations with anxiety and confusion were partially mediated. Further, the interaction of prayer frequency by stress was associated with anxiety.

Simultaneous, quantitative, narrow-line laser absorption measurements of CN time-histories at 388.444 nm and OH time-histories at 306.687 nm have been made in incident and reflected shock wave experiments using dilute mixtures of nitiric acid (HNO3) and HCN in argon. The thermal decomposition of HNO3 serves as a rapid source of OH upon shock-heating, and the OH subsequently reacts predominantly with the HCN in the test gas mixture. The rate coefficient for the reaction was determined in the temperature range 1120–1960 K via detailed kinetics modeling of the simultaneously acquired CN and OH measurements. These data are in good agreement with lower temperature measurements of the rate of the reverse reaction (−1a) when recent values of the heats of formation of CN and HCN are used. The expression valid for temperatures 500 to 2000 K, effectively represents the experimental measurements. The estimated uncertainty of the expression for k1a is ±30%, based on the experimental uncertainties of the individual rate coefficient studies. Analysis of the decay region of the experimental OH time-histories yielded the total rate coefficient k1 (all product channels) for the reaction of HCN with OH for temperatures ranging from 1490 to 1950 K. These measurements are consistent with a previous theoretical analysis of the three primary addition-isomerization-dissociation processes for the HCN + OH reaction at combustion temperatures when the contribution to k1 from reaction (1a) is included. © 1995 John Wiley & Sons, Inc.

Absorption line shapes in the (0,0) band of the B ← X violet system of CN are measured in shock tube experiments using a rapid-tuning narrow-line ring dye laser. Excimer photolysis at 193 nm and high temperature pyrolysis of C2N2−Ar mixtures are used for CN generation. In experiments using the shock tube as a room temperature (298 K) cell, the rotational quantum number (N″) dependence of the CN-Ar collision broadening coefficient is determined by modeling the recorded line shapes with Voigt profiles. Transitions in the P-branch with lower state rotational quantum numbers of N″ = 4−14 are probed; the expression 2γT=298KCN-Ar[cm−1atm−1] = 0.0560 exp(−0.201 N″) + 0.11 results. Shock tube experiments over the temperature range 1200–4500 K are used to determine the temperature dependence of the collision broadening coefficient, resulting in the expression 2γ CN-Ar [cm −1 atm −1 ] = 2γ T=298K Cn-Ar ( 298 T[K] ) 0.8 valid for temperatures from 298 to 4500 K. Additional measurements confirm the magnitude of the (0,0) band oscillator strength and validate the spectral absorption coefficients calculated with a spectroscopic model of the CN B ← X(0,0) system for a wide range of conditions.

The total rate coefficients for the reactions C N + N O 2 → p r o d u c t s (1) N C O + N O 2 → p r o d u c t s (2)were measured at temperatures between 1000 and 1600 K and pressures near 1.4 atm in a shock tube. Narrow-line laser absorption was utilized to record time histories of CN and NCO radicals in C2N2/NO2/Ar laser photolysis experiments. In the experiment, CN production is nearly instantaneous via photolysis of C2N2; production of NCO radicals follows from the main product channel of reaction (1). A least-squares fit to the results for reaction (1) is given by the expression k 1 = 1.59 × 10 13 exp ⁡ ( 570 / T [ K ] ) c m 3 m o l − 1 s − 1 with corresponding uncertainty factors of f=0.91 and F=1.09 at the low-temperature extreme; f=0.84 and F=1.17 result at the high-temperature extreme. The uncertainty factors give the limiting values of the rate coefficient: kmin=fkbest fit, {itkmax=Fkbest fit. The rate coefficient of reaction (2) was measured as k2=4.5×1012 cm3 mol−1 s−1 (f=0.75, F=1.27) for temperatures near 1250 K. Incorporating the data from the present study with the results from lower-temperature studies gives the following empirical expressions for the total rate coefficients valid for temperatures ranging from 300 to 1600 K: k 1 = 6.16 × 10 15 T [ K ] − 0.752 exp ⁡ ( − 173 / T [ K ] c m 3 m o l − 1 s − 1 k 2 = 3.25 × 10 12 exp ⁡ ( 356 / T [ K ] ) c m 3 m o l − 1 s − 1 .

Time-histories of the CN radical were monitored using a tunable ring dye laser to measure absorption at the P -branch bandhead of the B 2 ∑ + ← X 2 ∑ + (0,0) band of CN in a shock tube. Measurements of CN resulting from the pyrolysis of highly dilute mixtures of C 2 N 2 in Ar were compared with a spectroscopic model, and the location of maximum absorption for the bandhead was determined to be 25743.72 cm -1 (λ = 388.444 nm). A second set of experiments at the maximum absorption frequency was conducted for temperatures between 2700 and 4900 K and pressures between 0.34 and 1.0 atm. These measurements were used to determine an expression for the effective collisional broadening coefficient. Correlation of the data with the spectroscopic model led to a temperature- and pressure-dependent expression for the absorption coefficient. For P = 1 atm, this expression is of the form k v ( T , 1 atm) [cm -1 atm -1 ] = a / T 3 + b / T 2 + c / T , where a = −9.95984 × 10 13 , b = 1.13891 × 10 11 , and c = −1.16132 × 10 7 ; it agrees with the spectroscopic model within 1% for the temperature range 2000 T T T > 3300 K. The detection limit of the CN diagnostic is 0.1% absorption, which corresponds to a CN detection sensitivity of 0.02 ppm at T = 3600 K, P = 1 atm, and a path lenght of 14.3 cm.

The UV absorption spectra of CF(3)CHO, C(2)F(5)CHO, C(3)F(7)CHO, C(4)F(9)CHO, CF(3)CH(2)CHO, and C(6)F(13)CH(2)CHO were recorded over the range 225-400 nm at 249-297 K. C(x)F(2)(x)(+1)CHO and C(x)F(2)(x)(+1)CH(2)CHO have broad absorption features centered at 300-310 and 290-300 nm, respectively. The strength of the absorption increases with the size of the C(x)F(2)(x)(+1) group. There was no discernible (5%) effect of temperature on the UV spectra. Quantum yields for photolysis at 254 and 308 nm were measured. Quantum yields at 254 nm were 0.79 +/- 0.09 (CF(3)CHO), 0.81 +/- 0.09 (C(2)F(5)CHO), 0.63 +/- 0.09 (C(3)F(7)CHO), 0.60 +/- 0.09 (C(4)F(9)CHO), 0.74 +/- 0.08 (CF(3)CH(2)CHO), and 0.55 +/- 0.09 (C(6)F(13)CH(2)CHO). Quantum yields at 308 nm were 0.17 +/- 0.03 (CF(3)CHO), 0.08 +/- 0.02 (C(4)F(9)CHO), and 0.04 +/- 0.01 (CF(3)CH(2)CHO). The quantum yields decrease with increasing size of the C(x)F(2)(x)(+1) group and with increasing wavelength of the photolysis light. The photolysis quantum yield at 308 nm for CF(3)CHO measured here is a factor of at least 8 greater than that reported previously. Photolysis is probably the dominant atmospheric fate of C(x)F(2)(x)(+1)CHO (x = 1-4) and is an important fate of C(x)F(2)(x)(+1)CH(2)CHO (x = 1 and 6). These results have important ramifications concerning the yield of perfluorocarboxylic acids in the atmospheric oxidation of fluorotelomer alcohols.

Nanotechnology is and will be the foundation for exciting new technologies for years to come. Much of nanotechnology's promise is related to the unique properties that materials exhibit on the nanoscale. With such promise come questions concerning the environmental, safety and health (ESH) of the new technologies. As a result, a cross functional team of ESH experts from the chemical and semiconductor industries, with inputs from academic and governmental representatives, reviewed existing ESH and nanotechnology research and developed a list of over 30 research areas where ESH questions were unanswered. From this list, the top five research needs were identified and further explored based on the expertise of the team.

There is no published data regarding the financial impact of training orthopaedic residents in the operating room. No comparisons between orthopaedic faculty and residents in regard to operative time and costs are known. One hundred eleven cases of anterior cruciate ligament reconstruction with or without partial meniscectomy were evaluated from 1996 to 1997. Fifty-three cases met the selection criteria of times, documentation and identification of the surgeon. Twenty-one cases were performed by the orthopaedic attending (RCS) while 32 cases were performed by the senior orthopaedic resident. All procedures had the same faculty member present in the operating room either as the primary surgeon or as an assistant providing supervision and instruction as needed. In a two year period, comparisons were made between the attending and residents for the total anesthesia time and actual operative case time. Attending case time and anesthesia times averaged 94.62 minutes (range 60-125 min) and 128.1 minutes (range 84-185 min) respectively. Resident case and anesthesia times averaged 137.09 minutes (range 95-210 min) and 190.48 minutes (range 145-255 min) respectively. The anesthesia time was significantly less for the attending (p.0001) as was the case time (p.0001). The true costs of training orthopaedic surgery residents in the operating room is not known. The operative time and subsequent cost difference between experienced faculty and orthopaedic residents in certain arthroscopic procedures is not inconsequential. On average, the difference is equivalent to $228.73 per case for anesthesia costs. Based on increased operative times, operating room costs, on average, were increased by $661.85. The significant differences demonstrated between residents and faculty suggest the need to develop strategies and technical training facilities in order to improve orthopaedic residents' surgical skills and efficiency outside of the cost-central operating room.

The ascent to power of a Democratic administration promoting the value of government activism has generated questions about the ability of the federal bureaucracy to execute expanded missions. Bureaucracy is associated in the public mind with inefficiency and wastefulness. This public image, in combination with such factors as low pay and ineffective recruiting, has discouraged the best talent graduating from college each year from seeking employment in the public sector. This paper examines the increasing difficulty the government is having in attracting quality employees and offers recommendations for improvement

Strong tidal currents in the Sundays rive estuary, South Africa, prompted an investigation into the possibility of endemic populations avoiding or utilizing currents in a vertical and lateral plane as a mechanism of maintaining themselves within the estuary. The copepod, Pseudodiaptomus hessei avoided inflowing and outflowing surface currents, but migrated towards the surface at slack water. Acartia longipatella and A. natalensis remained in greater numbers near the bottom on the ebb tide, moving laterally into areas of slowest current velocity. Spatial distribution patterns of the two species of Acartia were maintained by different behavioural responses on the flood tide. A. longipatella was present in slower currents while. A. natalensis was present in greater numbers in faster flowing currents and so moved higher up the estuary than A. longipatella . The large mysid Rhopalophthalamus terranatalis was always present in greater numbers near the bottom, maintaining position through lateral migration, avoiding faster flowing currents on the ebb, but utilizing these faster currents on the flood tide to move up the estuary. Adults of the mysid, Mesopodopsis slabberi utilized both vertical and lateral migration as a means of maintaining position in the estuary.

All epifaunal and shallow-burrowing, intertidal macrofauna on an exposed sandy beach appear to undergo tidal migrations which vary in extent but are all upshore on the incoming tide and downshore on the outgoing tide during day and night. In the crustaceans this is probably endogenous rhythmic behaviour and they show increased activity at night. In the molluscs this movement is not synchronised by an intrinsic mechanism but results from behavioural responses to changing physical conditions. The large wedge clam, Donax serra, shows no tidal migrations but does show a semilunar rhythm of movement from just above mean tide level (MTL) during springs to the low tide level during neap tides.

A natalensis is more tolerant of low salinity and the replacement of A. longipatella by A. natalensis starts in the upper estuary and spreads seawards. Maximum abundance of A. natalensis is attained in water of lower salinity than in the case of A. longipatella. In the Sundays estuary A. natalensis appeared briefly in ihe latter half of the siudy and in the upper and middle estuary only. In the lower esiuary A. longipatella was present during all seasons. This was due to the absence of competition from A. natalensis, high salinity and lower summer Icmperaturcs due to marine influence. A third species of copepod, Pseudodiaptomus hessei functions as a pioneer species, exploiting "new waler" after flooding or strong fresh waier inflow. High abundance may therefore occur during any season and no competition between P. hessei and either species of Acartia was observed.

Breeding adults and larvae of Macropetasma africanus were sampled over a two-year period in Algoa Bay, South Africa. Gonadal macro-and microscopic examination enabled classification of breeding fem...

During the day the sand burrowing mysid Gastrosaccus psammodytes is confined to the intertidal and surf zone. There is a clear pattern of intraspecific zonation with adult males, immatures and juveniles furthest offshore. Females move progressively inshore as the brood develops, with young-bearing females occupying a zone closest inshore. At night G. psammodytes is present in the plankton when part of the population moves into deeper water and away from the area occupied during the day. Zonation appears to be related to the degree of planktonic activity. Loss or mortality of developing embryos is high in G. psammodytes and inshore movement of brooding females is interpreted as a movement away from excessive turbulence and sand movement in the area of breaking waves.

The physical features, macrofauna and meiofauna of four exposed sandy beaches along the southern coast of South Africa were quantitatively investigated. All beaches had medium to fine sands with relatively poor to moderate macrofauna and very rich meiofauna. The results are compared with the present knowledge of the southern African coastline. Sandy beaches types around the southern African coastline are summarized according to geomorphology and wave action and three Zoogeographie provinces are recognized. The macrofauna is dominated by crustaceans, mostly scavengers, on the warmer east coast and by molluscs, mostly filterfeeders, on the temperate south coast. Relationships between diversity and abundance of macrofauna, beach slope and particle size are analysed in detail. Intertidal zonation of macrofauna is described and a zonation scheme based on crustaceans proposed. Relationships between meiofauna composition and particle size are described as well as intertidal distribution patterns of the meiofauna...

A study of the plankton of the estuary system of Richards Bay in South Africa has been carried out by the plankton research group at the Port Elizabeth Museum. This study in conjunction with other ecological studies provide an environmental survey of the site of the Richards Bay Harbour now under construction. 2. Future studies will follow the changes that occur in the harbour and the new estuary being dredged for a nature reserve in the southern half of the bay. 3. Two different plankton communities are involved. In the channel area near the mouth a predominantly neritic marine plankton is found. In the lagoon area further up a true estuarine plankton occurs dominated by the CopepodaPseudodiaptomus andAcartia. 4. While species diversity is significantly higher in the channel area, the biomass of zooplankton is significantly higher in the lake area (up to 344 mg/m3). 5. A preliminary assessment of nett secondary zooplankton production gave a maximum value of 12 mg (dry wt)/m3/day. 6. The pattern of distribution of zooplankton found in this study was found to bear very little relation to the distribution of the physical and chemical parameters conventionally investigated such as salinity, temperature, dissolved oxygen and various nutrients. Tidal exchange appears to be the single most important factor controlling the distribution of zooplankton in Richards Bay. The estuarine zooplankton only survives beyond a point where the rate of tidal replacement is not too great. This boundary and areas of concentration appears to persist irrespective of the other environmental conditions prevailing. Variations in population structure indicate how tidal replacement and vertical migration affect their survival and productivity.

Summary McLachlan, A., Woodridge, T., Schramm, M. & Kuhn, M. 1980. Seasonal abundance, biomass and feeding of shore birds on sandy beaches in the Eastern Cape, South Africa. Ostrich 51:44-52. The numbers of birds on three Eastern Cape sandy beaches were monitored monthly over one year during 1977/78. Dominant among 17 species were the Southern Blackbacked Gull Larus dominicanus, Black Oystercatcher Haematopus moquini, Whitefronted Sandplover Charadrius marginatus and Sanderling Calidris alba. These four species made up 95% of bird numbers and their respective biomass values were 78 652, 7 695, 578 and 3 116 kJ/km shoreline. Total food consumption for these species, calculated on the basis of estimated standard metabolic rates, was 4 159 394, 521 149, 76 768 and 363 053 kJ/km respectively. Food composition and feeding behaviour are also discussed and the total quantity of intertidal macrobenthic animals consumed by birds estimated.

The euryhaline component of the Zooplankton in the Sundays River estuary was sampled monthly at 10 stations from August 1979 to April 1981. In deeper regions surface and near-bottom samples were taken (Stations 1-7) using WP2 nets. Shallow (< 2,0 m) stations were sampled in surface waters only. Water temperature ranged between 14-27 °C. A full salinity gradient was present and salinity stratification was well developed. Acartia longipatella was most abundant during winter and spring (maximum 73 300 m-3) in the lower estuary. The interaction of temperature and salinity as factors regulating temporal and spatial distribution was evident, these factors also interacting in the water column owing to stratification. The pioneer copepod species, seudodiaptomus hessei, attained high abundance following floods or increased river inflow. Three species of mysid shrimps were common in the plankton in summer, each species showing clear zones of maximum distribution. Zooplankton standing stock (dry mass) ranged from < ...

The short-term effect of elevated water temperatures (Δ t = 5–10°C after passing through the cooling circuit of an electricity generating plant) on plankton in a warm temperate estuary. South Africa, was investigated. Phytoplankton entrained on the flood tide was more severely affected than that entrained on the ebb, but chlorination of cooling water was probably a major factor affecting phytoplankton assemblages. Abundance of zooplankton of marine origin was significantly reduced after passing through the cooling circuit. The effect of thermal stress on the curyhalinc zooplankton was not clear, as the origin of the water canal to the generators is located at the extreme seaward limit of spatial distribution of cstuarinc plankton at low tide. Estuarinc species of zooplankton were therefore infrequently sampled and in low numbers only. Other factors which increase mortality are discussed.

Data from an ecological survey of four sandy beaches on the Natal coast of South Africa are presented. Physical parameters such as beach profile, particle size, moisture, Eh and carbonate content, as well as abundance, composition, biomass and distribution of both macrofauna and meiofauna were Investigated. A survey of the surf and swash zone mysids was also made. Natal beaches may be divided into two general types: (i) moderately exposed beaches of medium sand north of Blythdale with diverse meiofauna and typical sand beach macrofauna communities, and (ii) very exposed beaches of coarse sand south of Blythdale with true intertidal macrofauna often absent and a meiofauna dominated by large archiannelids.