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Effective cultural competency (CC) training for future health professionals is an important first step towards improving healthcare disparities (HCD). The Accreditation Council for Graduate Medical Education (ACGME) now requires that institutions train residents and faculty members in CC relevant to the patient population they serve.Using Kern's Model, we created and implemented a novel CC curriculum tailored to specific program needs in an emergency medicine residency program.At the end of the curriculum, respondents reported having a better understanding of the importance of CC for their practice (The challenges of CC training demonstrate the need for a standard yet adaptable framework. We have designed, implemented, and evaluated a novel curriculum tailored to the specific needs of our EM residency program. The curriculum improved participants' attitudes, preparedness, and self-reported behaviors regarding CC and HCD. This framework represents an example of a successful model to meet ACGME requirements.

Dilution with low-nutrient Columbia River Water (CRW) has markedly improved Moses Lake quality for 42 years. There were two phases of CRW volume input, which proportionately lowered total phosphorus (TP). Initially, spring-summer inputs averaged 130 × 106 m3 during 1977-1988 reducing average TP from 152 to 65 µg/L in half the lake proximal to the inputs. That input represented 1.5 volumes of that half-lake volume. Inputs doubled through the mid-1990s, and nearly 2.5 times since 2000, decreasing TP to a 18-year average of 24 µg/L. Chlorophyll a (chl) decreased further from 18 µg/L during the early dilution years to about 6 µg/L as TP declined. Cyanobacteria biovolume declined to 57% of total biovolume during 1977-1988 from 98% before dilution. Less (65%) CRW water since 2016 led to higher TP (41 µg/L) and chl (18 µg/L) in 2018, while cyanobacteria averaged 87% of total biovolume. More TP and cyanobacteria in 2018 are attributed to more internal TP loading. Increased N:P ratios have possibly given more advantage to the non-N-fixing cyanobacteria Microcystis, which comprised 82% and 74% of maximum cyanobacteria biovolume in 2017 and 2018. PRACTITIONER POINTS: Lake total phosphorus (TP) was reduced 57% in the 1970s-1980s by adding large volumes of low-nutrient Columbia River water (CRW). Total P was further reduced by 65% since 2000 by more than doubling the earlier CRW input to an average spring-summer concentration of 24 μg/L. Less (65%) CRW during 2017-2018 led to higher lake TP (41 μg/L) and a worse cyanobacteria bloom in 2018. Microcystis, an non-nitrogen fixer, was the dominant cyanobacteria in 2017-2018 likely related to higher N:P ratios.

New World screwworms, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae: Chrysomyinae), are devastating pests of warm-blooded animals that cause significant economic damage to livestock. The successful campaign to eradicate screwworms from continental North America, led by the US Department of Agriculture and using the sterile insect technique, continues to receive research support that has resulted in improved technologies for all aspects of the program. The process and ingredients for mass-rearing screwworms is more efficient and sustainable, and there is now a standardized protocol for developing new strains used in mass rearing. Cryopreservation of screwworm embryos allows strains to be preserved and recovered if necessary and also reduces rearing requirements for backup and research strains. Sterile fly release procedures and equipment have been updated leading to optimized sterile fly release rates. Surveillance for screwworm infestations and outbreaks have incorporated new trap designs, habitat analysis, and molecular genetic techniques that enhance monitoring the progress of the program as well as early detection and response to outbreaks. Genetic analyses of screwworm populations across their current range have increased the understanding of genetic differentiation, which may aide in developing new strains and determining the geographic origin of screwworms causing outbreaks when they occur. The ability to release only sterile males, which has been a goal of the program for over 60 years, has recently been accomplished through the development of transgenic sexing strains. The strains carry a conditional female lethal gene and are comparable to the wild-type strain for several biological parameters that are important for mass production and performance in the field. The strains should improve efficiency of population suppression of the current and future eradication and prevention programs against screwworms. These research advances as well as future considerations are presented.

For patients dependent on parenteral nutrition (PN), selenium must be supplemented intravenously. A nationwide intravenous selenium shortage began in April 2011. The impact of this shortage on PN-dependent infants was evaluated by examining the provision of selenium, development of biochemical deficiency, and costs associated with the shortage.This single-center, retrospective study included PN-dependent infants aged ≤1 year who weighed ≤30 kg, received PN for ≥1 month, and had ≥1 serum selenium measurement. The primary outcome was the incidence of biochemical selenium deficiency. Secondary outcomes included severity of biochemical deficiency, clinical manifestations, costs, and relationship between serum selenium levels and selenium dose.The average selenium dose decreased 2-fold during the shortage (2.1 ± 1.2 µg/kg/d; range, 0.2-4.6 µg/kg/d) versus the nonshortage period (3.8 ± 1 µg/kg/d; range, 2.4-6 µg/kg/d; P.001). A linear relationship between serum selenium concentration and selenium dose was observed (r(2) = 0.42), with a dose of 6 µg/kg/d expected to result in normal serum levels in most cases. Similar proportions of patients developed biochemical deficiency in both groups: shortage period, 59.1%; nonshortage, 66.7%; P = .13. The severity of biochemical deficiency was similar between groups. A significant increase in incremental cost during the shortage was observed.This is the first study examining the impact of the intravenous selenium shortage on PN-dependent infants. Both groups exhibited similarly high incidences of biochemical selenium deficiency, suggesting higher empiric doses may benefit this population. However, ongoing shortages limit the ability to provide supplementation.

BACKGROUND The high value of the specific absorption rate (SAR) of radio-frequency (RF) energy arising from the series of RF refocusing pulses in T2-weighted (T2-w) turbo spin echo (TSE) MRI hampers its clinical application at 7.0 Tesla (7T). T2-w gradient and spin echo (GRASE) uses the speed from gradient refocusing in combination with the chemical-shift/static magnetic field (B0) inhomogeneity insensitivity from spin-echo refocusing to acquire T2-w images with a limited number of refocusing RF pulses, thus reducing SAR. OBJECTIVES To investigate whether low SAR T2-w GRASE could replace T2-w TSE in detecting white matter (WM) disease in MS patients imaged at 7T. METHODS The .7 mm3 isotropic T2-w TSE and T2-w GRASE images with variable echo times (TEs) and echo planar imaging (EPI) factors were obtained on a 7T scanner from postmortem samples of MS brains. These samples were derived from brains of 3 female MS patients. WM lesions (WM-Ls) and normal-appearing WM (NAWM) signal intensity, WM-Ls/NAWM contrast-to-noise ratio (CNR) and MRI/myelin staining sections comparisons were obtained. RESULTS GRASE sequences with EPI factor/TE = 3/50 and 3/75 ms were comparable to the SE technique for measures of CNR in WM-Ls and NAWM and for detection of WM-Ls. In all sequences, however, identification of areas with remyelination, Wallerian degeneration, and gray matter demyelination, as depicted by myelin staining, was not possible. CONCLUSIONS T2-w GRASE images may replace T2-w TSE for clinical use. However, even at 7T, both sequences fail in detecting and characterizing MS disease beyond visible WM-Ls.

The overall purpose of these guidelines is to provide guidance on best clinical practice in the treatment and management of human immunodeficiency virus (HIV)-positive pregnant women in the UK. The scope includes guidance on the use of antiretroviral therapy (ART) both to prevent HIV mother-to-child transmission (MTCT) and for the welfare of the mother herself, guidance on mode of delivery and recommendations in specific patient populations where other factors need to be taken into consideration,such as coinfection with other agents. The guidelines are aimed at clinical professionals directly involved with, and responsible for, the care of pregnant women with HIV infection.

Providing a reliable hot surface ignition system (glow plug, GP) for natural gas-direct injection engines is challenging. This paper presents experimental results of aging all-ceramic Si3N4-based GPs in an engine, continuing previously published results on electric and gas burner rigs. The microstructural modifications of the ceramic heater, leading to degradation and ultimately to failure, are effected by four synergistic mechanisms: electrical, chemical, mechanical, and thermal. GP lifetime in engine follows the general Arrhenius law, with activation energy of 5.2 eV, (vs 9.1 V on burner rig and 13.8 eV on electric rig, as reported previously), suggesting additional factors contributing to GP failure in the engine.

Trace elements (TEs) dosing and monitoring in home parenteral nutrition (PN) patients vary with their underlying conditions.This retrospective observational study evaluated parenteral TE dosing, serum TE concentrations and monitoring, and dose-concentration relationships between TE doses and serum TE concentrations in 26 adult and adolescent home PN patients.There was a total of 40,493 PN days. Average parenteral zinc doses of 9.1 mg/d and 7.6 mg/d resulted in the majority of serum zinc concentrations (90%) within normal range in patients with and without short bowel syndrome (SBS), respectively. Selenium at about 70 mcg/d resulted in about 60% of serum selenium concentrations within normal range, with 38% of values below normal in patients with and without SBS alike. Copper at 1 mg/d resulted in 22.5% of serum copper concentrations above the normal range. The majority of serum manganese (94.6%) and chromium (96%) concentrations were elevated. Serum TE concentrations were infrequently monitored. Significant relationships existed between doses and serum concentrations for zinc (P.0001), manganese (P = .012), and chromium (P.0001) but not for selenium or copper.TE doses in home PN should be individualized and adjusted based on regular monitoring of TE status. In long-term home PN patients, higher zinc and selenium doses may be necessary to maintain their normal serum concentrations. Lower copper doses and restrictions of manganese and chromium supplementation may be needed to avoid their accumulation. Relationships between TE doses and serum TE concentrations vary for each TE and underlying clinical conditions.

In the development of advanced natural gas and hydrogen direct injection combustion engines, a challenge is providing reliable hot-surface (glow plug, GP) ignition systems; most promising are GPs with silicon nitride-based heaters. This paper presents experimental results of accelerated degradation tests of the GPs on natural gas-burning rig, continuing previously published results on GP degradation in air. Degradation, ultimately leading to GP failure, occurs through the synergistic effects of electric field and chemical reactions in the combustion environment. The resulting microstructural modifications of the ceramic heater, studied by SEM/EDS, are a combination of sintering additive ions migration and surface oxidation.

All-ceramic glow plugs (GP) based on sintered-silicon nitride are evaluated as hot surface ignition systems for natural gas and hydrogen direct injection combustion engines. This paper presents experimental results of the accelerated degradation tests of the GPs in air, wherein GP is heated solely by dc electricity. The complex degradation process has been linked mostly to the redistribution of the sintering additives in Si3N4/Yb2O3 system under an influence of dc electric field and temperatures over 1300°C, as experienced by GP in-service. Ytterbium ions migration varies with time, temperature, and voltage. The microstructural damage was studied primarily by SEM microscopy.

Study Objective. To assess the effectiveness, safety, and cost of empiric treatment of febrile neutropenia before and after implementing an algorithm in which voriconazole was substituted for liposomal amphotericin B (L-AmB). Design. Retrospective cohort analysis. Setting. An 850-bed tertiary care hospital, which is also a referral site for patients with acute leukemia. Patients. Fifty-five adult patients who started empiric antifungal therapy for febrile neutropenia between January 1, 2002, and December 31, 2003, encompassing 58 treatment episodes (defined as a hospitalization during which empiric antifungal therapy was administered). Measurements and Main Results. Medical charts, including patients’ pharmacy and laboratory data, were reviewed. Twenty-six and 32 episodes of L-AmB and voriconazole use, respectively, were identified. No significant differences between the L-AmB and voriconazole groups were noted at baseline. Rates of fever resolution (54% vs 59%, p=0.791) and breakthrough invasive fungal infections (11% vs 12%, p>0.999) were similar for the L-AmB and voriconazole episodes. Premature drug discontinuation due to the prescriber’s perceived lack of efficacy occurred most frequently in the voriconazole group (25% vs 8%, p=0.160). Survival was significantly higher in the voriconazole than in the L-AmB group (100% vs 77%, p=0.006). Adverse effects that were significantly more common in the L-AmB group than in the voriconazole group were elevated serum creatinine levels (27% vs 3%, p=0.017) and electrolyte disturbances (19% vs 0%, p=0.014). Adverse effects reported more frequently in the voriconazole group than in the L-AmB group were visual disturbances (9% vs 0%, p=0.245) and elevated hepatic enzyme levels (9% vs 8%, p>0.999). Mean drug expenditures/episode for initial empiric antifungal therapy were lower for voriconazole than for L-AmB ($1593 vs $4144, or $153 vs $380/day). Conclusion. Our institution’s algorithm incorporating voriconazole into the empiric management of febrile neutropenia was associated with effectiveness outcomes comparable to those observed with L-AmB as well as a lower frequency of adverse effects and overall expenditures for antifungal drugs.

Objectives: To evaluate the performance and the utility of using birthweight-adjusted scores of Dubowitz and Ballard methods of estimating gestational age in a Zimbabwean population. Method: The Dubowitz and the Ballard methods of estimating gestational age were administered to 364 African newborn infants with a known last menstrual period (LMP) at Harare Maternity Hospital. Results: Both methods were good predictors of gestational age useful in differentiating term from pre-term infants. Our regression line was Y (LMP gestational age) =23.814+0.301*score for the Dubowitz and Y (LMP gestational age) =24.493+0.420*score for the Ballard method. Addition of birthweight to the regression models improved prediction of gestational age; Y (LMP gestational age) =23.512+0.219*score+0.0015*grams for Dubowitz and Y (LMP gestational age) =24.002+0.292*score+0.0016*grams for Ballard method. Conclusions: We recommend the use of our birthweight-adjusted maturity scales; the Dubowitz for studies of prematurity, and the Ballard for routine clinical practice.

The effectiveness of aluminum (Al) at retaining phosphate was investigated in alum-treated Washington lake sediments. Greater than background concentrations of Al and Al-bound phosphorus (Al-P) were detected in three stratified lakes (Lake Ballinger, Phantom Lake, and Medical Lake) and in three unstratified lakes (Lake Erie, Cambell Lake, and Long Lake). The ratio of added Al to P (Al:Al-P) was approximately 11:1 by weight in all six lakes. Added Al ranged from 6 to 83 g Al m-2 , and adsorbed P subsequently ranged from 0.5 to 7.3 g P m-2. P bound to the added Al was apparently removed from the P cycle, as the layers of increased Al-P due to treatment were buried in the sediment at a depth corre-sponding to the approximate time since treatment.

Summary 1. The proliferation of nuisance periphyton in enriched streams may be dependent on the biomass of the grazing macroinvertebrates present. In the present study, the effectiveness of grazer size and biomass in controlling periphyton and the extent to which grazing effectiveness was affected by enrichment level were determined. 2. Two sets of experiments with two caddisfly grazers were conducted in laboratory channels during spring and summer 1995 and 1996. The first set tested the combined effect of phosphorus enrichment and grazing, while the second set tested the effect of variable grazer biomass on periphyton biomass. 3. Grazing reduced periphyton biomass in excess of 80%, compared to ungrazed controls. Grazers were equally effective in controlling filamentous green algae, Stigeoclonium, diatoms and small colonial greens. Near complete removal of periphyton biomass by grazing occurred at even at the lowest grazer biomass level (750 mg m−−2, i.e. approximately one-third of natural levels). 4. Grazing controlled periphyton biomass more than did enrichment with soluble reactive phosphorus (SRP). 5. Grazing rates in the phosphorus-grazing interaction experiments averaged about 6 mg chl a g invertebrate−−1 day−−1, which was similar to past work in these channels and elsewhere, while rates were about five-fold higher in the variable grazer biomass experiments. 6. Simulating effects of SRP and grazing with a calibrated model suggests that higher SRP levels would be necessary to exceed a nuisance periphyton biomass level if grazers were present. However, if grazer biomass was more than 1500 mg m−−2, a nuisance level would probably not be exceeded at any SRP.

Fluorescent and photolabile nucleotide analogues 1 and 2 were prepared to test an unconventional approach to DNA sequencing that, ideally, would not involve gel electrophoresis. These particular compounds were not incorporated, but modeling studies indicate how further refinements to their structures could facilitate the proposed sequencing scheme. B = adenine, thymine; TP = triphosphate

The Quebec platelet disorder is a serious bleeding disorder associated with proteolysis of alpha-granular proteins, including fibrinogen. We evaluated fibrinogen degradation product (FDP) assays as screening tests for this disorder. Patients with the Quebec platelet disorder (13/13) had elevated serum FDPs (P < 0.01) due to secreted degraded platelet fibrinogen, but normal plasma FDPs and D-dimers. Unrelated controls with bleeding disorders (32/34) had undetectable FDPs, and controls with FDPs due to disseminated intravascular coagulation (DIC) and other illnesses (11/11) had elevated FDPs in all assays (P < 0.01). Immunoblot analyses indicated plasma fibrinogen was normal in the Quebec patients and platelet FDPs were found in their platelet lysates, releasates and serum samples. Their platelet FDPs were not altered by treatment with fibrinolytic inhibitors and were different from the FDPs in DIC and in plasmin-digested fibrinogen. Tests for serum FDPs may provide a simple rapid way to screen for the Quebec platelet disorder.

In this paper, we describe a method for estimating animal population density per unit area from mark, release, recapture (MRR) data. Standard procedures are available for estimating population size from MRR data, but not density per unit area, which is often of more practical value. If data on dispersal movements are available in addition to cap- ture/recapture records, they can be used to estimate the area over which the study population ranges. These area estimates can then be combined with MRR abundances to yield estimates of population density. As a concrete example of how these methods can be applied, we calculated population density estimates for seven MRR data sets for the screwworm, Coch- liomyia hominivorax (Diptera: Calliphoridae), from Costa Rica. As a standard of compar- ison, we also used a different method to calculate estimates of screwworm density for five sets of USDA APHIS Screwworm Eradication Program data from Mexico. Mean densities for both sets of analyses were similar, ranging from 10 to 120 adult flies/km2. General agreement between the Mexican and Costa Rican estimates lends support to the dispersal approach we propose here. Although we have applied these methods to the screwworm as a specific example, they are entirely general and can be applied to virtually any organism for which both MRR records and dispersal data are available.

This study surveyed senior corporate financial executives to determine their views on Eastern European business opportunities. Responses cover a broad range of topics and provide new insight into their perceptions and experiences about key factors that influence investment decisions: expected profitability, risk, resources, and timing. An optimistic view emerged. This is noteworthy in light of the reputation of CFOs for caution, conservatism, and reticence. Their perception of a favorable return-risk ratio may serve as further encouragement for those considering Eastern European ventures. © 1993 John Wiley & Sons, Inc.

Optimal catalysts for the key cyclopropanation step in a synthesis of the title compound were identified by screening libraries of metal complex–ligand combinations; the synthesis was completed, and a derivative of the final product was crystallized to establish its solid state conformation.

The dansylated nucleoside triphosphates 1a and 1b were prepared as a prelude to investigating sequencing of DNA via a scheme that does not involve electrophoresis.

The constrained dye 3 was prepared and shown to have a sharper, red-shifted, and more intense fluorescence emission than the 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY®) dye 2 in which the aryl groups can rotate freely.

SUMMARY 1. A two-season investigation was undertaken to determine the contribution of benthic recruitment to the population development of several species of blue-green algae. 2. Gloevtrichia echinulata populations were shown to be heavily subsidized by benthic recruitment, deriving on average 40% of their planktonic colonies from the benthos. 3. Benthic recruitment of Aphanizomenon flos-aquae, Anabaena flos-aquae and a second Anabaena species contributed less than 2% to planktonic increases, while Microcystis aeruginosa recruitment was negligible. 4. Phosphorus translocation via migrating G. echinulata accounted for most of the phosphorus (P) in the planktonic colonies, and constituted a significant portion of the internal loading of the lake. 5. Estimated P translocation via Aph. flos-aquae was relatively minor, although there was evidence of luxury uptake in the benthos.

SUMMARY. 1 Research was performed in laboratory streams to evaluate periphytic biomass accrual, export, and community composition over a range of limiting nutrient (phosphorus) concentrations with variable velocity, and suspended sediment addition, in comparison to constant velocity and no suspended sediment. In fixed-velocity treatments, velocity increase to 60 cm s−1 significantly enhanced biomass accrual, but further increase resulted in substantial biomass reduction. Average biomass loss rates did not change significantly over a velocity range of 10–80 cm s−1. Diatoms were favoured at relatively high velocities and low phosphorus concentrations, whereas the blue-green Phormidium tended to dominate at higher SRP concentrations and the green Mougeotia seemed to prefer lower velocities. 2 Sudden increases in velocity raised instantaneous loss rates by an order of magnitude or more, but these high rates persisted only briefly. As a result, marked biomass reductions were not apparent a day after the velocity change. Dominance change from filamentous green or blue-green to diatoms immediately after the increase was reversed within 2 days. Loss rate increases due to solids addition were much smaller than those accompanying velocity increase, but simultaneous velocity elevation and solids addition produced instantaneous loss rates approximately double those with velocity increase alone. 3 The experiments demonstrated that an elevation in velocity, above that to which algae were accustomed, led to increased loss rates and temporarily reduced biomass. However, recolonization and growth after biomass reduction were apparently rapid. Substantial export of periphyton following solids addition required erosion of the protective boundary layer accompanied by a velocity increase. These results arc applicable to understanding the response of lotic periphytic algae to elevated, turbid storm discharges and similar runoff or high-flow events. 4 Areal uptake rates of P by algae growing in the laboratory streams increased with soluble reactive phosphorus (SRP) concentration, up to approximately 15 μg I−1 in overlying water. They also increased above 35 cm s −1. Overall, uptake rate seemed to vary inversely with biomass. The ralio of areal uptake rate/biomass was significantly less where mean biomass was 411±6 mg chl a m−2 compared to 223±17 mg chl a m−2. 5 The results suggested that although nutrient uptake is primarily a surface phenomenon, diffusion to interior cells can also determine the responses of attached communities. Both diffusion and uptake rate were stimulated by increasing nutrient concentration and velocity up to certain levels, but became limited by biofilm thickness and scouring.

Conventional laboratory equipment used in seed germination research provides only constant and alternating temperature. The temperature of the soil in the seed bed is hardly ever constant or alternating in the same manner, but fluctuates constantly. In order to simulate the fluctuation of soil temperature that occurs in the field, a soil temperature simulator (STS) was designed, built, and evaluated. Plastic crispers containing soil in which seed are to be planted can be partially submerged in a rectangular tank into which water can be placed to a depth of 10 cm. Temperature of the water can be adjusted by heating and refrigeration systems under the control of a variable input programmer system. Maximum capabilities of the STS are: (i) maximum temperature drop 4 °C/h, (ii) maximum temperature rise 7.5 °C/h, and (iii) maximum temperature gradient within the unit 1.0 °C. The STS is capable of simulating fluctuations in soil temperature within a range of 4 to 40 °C and is particularly suited for the study of seed imbibitional chilling injury. Journal no. J-7253

In vivo experiments were performed to study elution rates of antibiotics combined with Surgical implex bone cement and efficacy in controlling bacterial infections. Cylinders of bone cement were implanted in animals and at the same time the surgical areas were infected with large numbers of bacteria. Gentamicin and Keflin were eluted from the cylinders in sufficient quantities to completely eliminate or markedly reduce the number of bacteria recovered from infected areas. Animals were also treated with an anti-inflammatory drug, hydrocortisone, prior to implantation of cylinders and infection. The antibiotics in the bone cement effectively destroyed the bacteria in these animals with impaired inflammatory responses as compared with control animals.

SUMMARY A model is proposed for measuring the genetic ‘distance’ between two populations having gene frequencies p and p*. The measure of distance is based on a hypothetical selection process as follows: From population Pasubpopulation P* can be selected having gene frequency p*. Let P 0 be the largest subpopulation yielding gene frequency p*, then the relative size of P 0 to P -denoted by θ0(pp*)-is a measure of the ‘closeness’ of populations having gene frequencies p and p*, and 1 - θ0(p, p*) would be a reasonable measure of genetic distance. We show that the calculation of θ0(p, p*) is a special case of the linear programming problem and derive algebraic expressions for θ0(p, p*) in the two-allele case. We discuss some of the implications of the use of this measure of distance and compare it to others which have been proposed. We use linear programming methods to calculate genetic distance for three alleles.

We have studied the concentration and ionic strength dependence of the fiber-reorientation transition in T2L bacteriophage, using sedimentation velocity and quasielastic light scattering diffusion measurements. High-salt and low-phage concentration favor the form with fibers extended. The equilibrium between the two forms is dependent on the phage Concentration. This behavior is unexpected for a reaction that is apparently unimolecular with respect to phage, and attests to the strong increase in excluded volume and other interactions accompanying fiber extension. The fiber-extended form has anomalously high diffusion coefficient and low molecular weight according to the Svedberg equation.

An alum treatment in Long Lake (mean depth, 2 m) in 1980 has been effective at controlling internal loading of phosphorus for four years. The fifth summer after treatment, the lake returned to its pro-treatment state. Lake P content decreased from a summer average of 65 μg/L during 1976–1978 to about 30 μg/L during four years following treatment. In 1985, summer P content was 61 μg/L. Algal abundance, species composition, and transparency have responded proportionately with P. Alum effectiveness apparently declined because the floe layer tended to sink and become dispersed at a deeper level in the sediment, as well as become covered with new, P-rich sediment. Iron-reduction may be the principal mechanism for internal P loading, although the lake is unstratified and anoxia is usually not pronounced.

Alum treatment of a shallow lake, with mean depth 2 m and area 137 ha, curtailed internal loading of P for at least one ear. Mean summer total P and chl a decreased from 76 and 27μg l−1, respectively, in 1978 before treatment. to 29 and 14 μ l−1, while mean summer Sed transparency increased from 1.6 to 2.2 m and blue green algae were no longer dominant. Macrophyte biomass and distribution retuned during the post-alum year, 1980-1981, to previous levels after a 1979 four-month lake level drawdown had reduced biomass by 84 percent The improved transparency, resulting from the decrease in chl a following treatment, could encourage greater biomass of macrophytes in the deeper area of the lake. Recovery of macrophyte biomass to predrawdown levels may restore internal loading of P through enrichment of deep water sediments during winter dieback and decomposition.

The breeding genetic distance measure of a single locus (Carlson & Welch, 1977) is extended to polygenic traits. For two populations with means -x and approximately x, theta(-x, approximately x) is defined as the size of the largest subpopulation with mean approximately x which can be (artificially) selected from a population with mean -x. The distance is defined as 1--theta(-x, approximately x). It is shown that theta(-x, approximately x) can be calculated from truncation selection and formulas (two loci) and tables (three and four loci) are given. Values for theta(-x, approximately x) based on a normal approximation are seen to be adequate for most cases. The measure is applied to a data example (human skin colour) and to a discussion of the idea of 'genetic inertia'.

The effect of combining gentamicin and cephalothin with Surgical Simplex bone cement was tested in vitro. Experiments were designed to determine (1) quantitative elution rates and period of time the antibiotics were eluted and (2) effective bactericidal qualities. Both antibiotics were eluted from polymerized acrylic cement in large quantities within 24--48 hr after coming in contact with fluid and continued to be released in smaller amounts for 21 days to more than 175 days. This varied with the antibiotic, concentration of antibiotic in the cement, surface area of cement, and volume of elution fluid. Quantitative determinations of numbers of bacteria in broth cultures demonstrated that sufficient quantities of antibiotics were released to be bactericidal to microorganisms within 45 min to 20 hr. This was dependent on the type of antibiotic, type of bacteria, concentration of antibiotic in the cement, and time of contact.

The seasonal pcriodicity of periphyton growth in the Duwamish estuary (Washington) is compared with that of phytoplankton and lends support to a previous conclusion that hydrographic conditions determine the timing of phytoplankton blooms despite high conten trations of dissolved nitrogen and phosphorus. Accumulation of periphyton on substrates increased in June and July to around 10 pg Chl a cm-’ week-l and is related to incident light; conversely, phytoplankton blooms were delayed until August and September when hydrographic conditions were optimum for biomass accumulations of from 30-70 pug Chl a/liter. Maximum growth of pcriphytic and planktonic algae occurred at the same location in the estuary, This similarity in spatial distribution is not directly related to hydrographic conditions since the periphyton algae arc sessile and more resistant to washout. The water in this section of the estuary presumably contained a more adequate supply of one or more limiting nutrients than water from adjacent locations.

Summary A prospective randomised double blind study was carried out to compare the use of epidural methadone, morphine and bupivacaine for pain relief after Caesarean section. The results indicate that methadone is the most effective agent with few side effects. Subsequently this method was used routinely for postoperative analgesia in all patients undergoing Caesarean section. A retrospective study of 178 patients having this method of analgesia was carried out and indicated that epidural methadone is an effective and safe method of postoperative pain relief.

Radiation-resistant micrococci isolated from chicken were studied because of their hemolytic properties. Morphology, growth, and physiological characteristics were similar in most ways to the common microcococci. There were some differences in pigmentation, nitrate reduction, hydrolysis of proteins, and salt tolerance. None of these characteristics appeared to be uniquely linked to radiation resistance of micrococci. Present knowledge does not indicate these bacteria to be of public health significance or to pose an organoleptic problem in quality protection.

Electric Utility Diversification and Efficient Capital Markets Over 60% of investor owned electric utilities have experimented with diversification into lines of business other than the traditional generation, transmission, and distribution of electricity. They diversify for a variety of reasons, but a primary goal is to improve their overall financial performance. Existing studies have found that diversified utilities outperform non‐diversified utilities. Measures of performance have included EPS growth, price‐earnings multiples, market‐book ratios and internal rates of return. However, many of these studies do not compare performance on a risk‐adjusted basis nor indicate whether differences are statistically significant. In contrast, this study compares performance using the efficient market hypothesis. Regression results indicate that there is no significant difference in risk between portfolios comprised of diversified utilities and non‐diversified utilities. Furthermore, no significant difference in return was observed. The performance of the two portfolios does not appear to differ in risk or return. These results tend to support the efficient market hypothesis concerning stockholders' inability to gain an advantage from publicly available information. Differences in company performance that are anticipated and already reflected in stock price do not result in differences in returns to stockholders.