Effect of sample type and the use of high or low fishmeal diets on bacterial communities in the gastrointestinal tract of Penaeus monodon.

In shrimp aquaculture, manufactured diets that include various supplements and alternative fishmeal ingredients are increasingly being used and their effect on the gastrointestinal (GI) microbiota studied. However, dietary effects on different shrimp GI samples are not known. We investigated how a high (HFM) or low (LFM) fishmeal diet affects bacterial communities from different sample types collected from Penaeus monodon gastrointestinal tract. Bacterial communities of the stomach, intestine tissue and intestine digesta were assessed using 16s rRNA gene sequencing. The feed pellets were also assessed as a potential source of bacteria in the GI tract. Results showed substantial differences in bacterial communities between the two diets as well as between the different sample types. Within the shrimp GI samples, stomach and digesta communities were most impacted by diet, while the community observed in the intestine tissue was less affected. Proteobacteria, Firmicutes and Bacteroidetes were the main phyla observed in shrimp samples, with enrichment of Bacteroidetes and Firmicutes in the LFM fed shrimp. The feed pellets were dominated by Firmicutes and were largely dissimilar to the shrimp samples. Several key taxa were shared however between the feed pellets and shrimp GI samples, particularly in the LFM fed shrimp, indicating the pellets may be a significant source of bacteria observed in shrimp GI samples. In summary, both diet and sample type influenced the bacterial communities characterised from the shrimp GI tract. Thus, it is important to consider the sample type collected from the GI tract when investigating dietary impacts on gut bacterial communities in shrimp. KEY POINTS: • Shrimp gastrointestinal communities are influenced by diet and sample type. • The low fishmeal diet enriched bacteria that aid in polysaccharide metabolism. • Feed pellets can be a source of bacteria-detected gastrointestinal tract of shrimp.

A modular ultra-high vacuum millikelvin scanning tunneling microscope.

We describe the design, construction, and performance of an ultra-high vacuum (UHV) scanning tunneling microscope (STM) capable of imaging at dilution-refrigerator temperatures and equipped with a vector magnet. The primary objective of our design is to achieve a high level of modularity by partitioning the STM system into a set of easily separable, interchangeable components. This naturally segregates the UHV needs of STM instrumentation from the typically non-UHV construction of a dilution refrigerator, facilitating the usage of non-UHV materials while maintaining a fully bakeable UHV chamber that houses the STM. The modular design also permits speedy removal of the microscope head from the rest of the system, allowing for repairs, modifications, and even replacement of the entire microscope head to be made at any time without warming the cryostat or compromising the vacuum. Without using cryogenic filters, we measured an electron temperature of 184 mK on a superconducting Al(100) single crystal.

Bioenergetics of Nutrient Reserves and Metabolism in Spiny Lobster Juveniles Sagmariasus verreauxi: Predicting Nutritional Condition from Hemolymph Biochemistry.

The nutritional condition of cultured Sagmariasus verreauxi juveniles over the molt and during starvation was investigated by studying their metabolism, bioenergetics of nutrient reserves, and hemolymph biochemistry. Juveniles were shown to downregulate standard metabolic rate by as much as 52% within 14 d during starvation. Hepatopancreas (HP) lipid was prioritized as a source of energy, but this reserve represented only between 1% and 13% of the total measured energy reserve and was used quickly during starvation, especially in the immediate postmolt period when as much as 60% was depleted within 3 d. Abdominal muscle (AM) protein represented between 74% and 90% of the total measured energy reserve in juvenile lobsters, and as much as 40% of available AM protein energy was used over 28 d of starvation after the molt. Carbohydrate reserves represented less than 2% of the measured total energy reserve in fed intermolt lobsters and provided negligible energy during starvation. Eighteen hemolymph parameters were measured to identify a nondestructive biomarker of condition that would reflect accurately the state of energy reserves of the lobster. Among these, the hemolymph Brix index was the most accurate and practical method to predict HP lipid and the total energy content of both the HP and the AM in juvenile S. verreauxi. The Brix index was strongly correlated with hemolymph proteins, triglyceride, cholesterol, calcium, and phosphorus concentrations, as well as lipase activity; all were useful in predicting condition. Electrolytes such as chloride, magnesium, and potassium and metabolites such as glucose and lactate were poor indicators of nutritional condition. Uric acid and the "albumin"-to-"globulin" ratio provided complementary information to the Brix index, which may assist in determining nutritional condition of wild juvenile lobsters of unknown intermolt development. This study will greatly assist future ecological studies examining the nutritional condition of juvenile lobsters in the wild, as well as the development of husbandry protocols and feeds for aquaculture.

Efficacy of glycine powder air polishing in comparison with sodium bicarbonate air polishing and ultrasonic scaling - a double-blind clinico-histopathologic study.

BACKGROUND: Subgingival biofilm removal using glycine powder air polishing (GPAP) has antecedently been shown to be safe. The hypothesis that GPAP is efficacious during periodontal maintenance therapy and results in less gingival erosion than sodium bicarbonate air polishing (SBAP) or ultrasonic scaling was assessed. METHODS: Initial periodontal therapy was performed in each of the 22 chronic periodontitis patients having residual 5 mm probing depth in each quadrant and were randomly assigned to one of the following interventions: GPAP (test), SBAP (positive control), ultrasonic scaling (positive control) or no treatment. Clinical parameters were assessed, and gingival biopsies were taken immediately after instrumentation and sent for histological quantification. RESULTS: Significant improvement in plaque and gingival index scores were noted in glycine powder air-polishing and ultrasonic group. GPAP resulted in minor erosion of the gingival epithelium (score 1 & 2), whereas positive control specimens displayed moderate to severe erosions (score 3 & 4). Difference between GPAP and positive control was significant. (P < 0.05). CONCLUSION: GPAP results in clinically significant improvement in plaque and gingival index scores and histologically causes less gingival erosion than SBAP or ultrasonic instrumentation, further supporting the safety of this debridement technique in periodontal maintenance therapy.

Comparison of visual inspection and Papanicolau (PAP) smears for cervical cancer screening in Honduras: should PAP smears be abandoned?

OBJECTIVE: To compare visual inspection with acetic acid (VIA) to Papanicolau (PAP) smears in a community setting in a developing nation. METHODS: Women undergoing cervical cancer screening in Honduras received either VIA and PAP smears (VIA/PAP group) or PAP smears alone (PAP-only group). Local healthcare providers performed PAP screening. A VIA-trained nurse performed VIA exams. All PAP smears were processed in Honduras. PAP smears from the VIA/PAP group were reviewed in the United States. Women with positive VIA or PAP tests were offered colposcopy. We compared the relative accuracy of PAP smears and VIA and the proportions of women completing follow-up colposcopy after positive screening tests. RESULTS: In total, 1709 PAP smears were performed including women from both the VIA/PAP and PAP-only groups. Nine PAP smears were positive (0.5%). Three women completed colposcopy (33%). All three had biopsy-confirmed dysplasia. In the VIA/PAP group (n = 339), 49 VIA exams were abnormal (14%) and two PAP smears were abnormal when read in Honduras (0.6%). When reviewed in the United States, 14 of the 339 PAP smears were abnormal (4%). Forty women (83%) completed follow-up colposcopy after a positive VIA exam. Twenty-three had biopsy-proven dysplasia. All 23 dysplasia cases had negative PAP smear readings in Honduras; four PAP smears were reclassified as positive in the United States. CONCLUSIONS: Although few developing countries can maintain high-quality PAP smear programmes, many governments and charitable organizations support cervical cancer screening programmes that rely on PAP smears. This study underscores the need to promote alternative technologies for cervical cancer screening in low-resource settings.

Pegylation of interferon alfa: structural and pharmacokinetic properties.

The attachment of a polyethylene glycol (PEG) polymer to a protein or peptide is becoming increasingly common within the pharmaceutical industry as a way of altering the activity of the parent molecule. Significant improvements in biological activity with PEG molecules have been seen with several licensed drugs, allowing for product life cycle management, as well as with experimental compounds in development that have pharmaceutical properties making them suitable candidates for pegylation. Among the various disease states that have been targeted for the study of drugs incorporating pegylation technology, the treatment of chronic hepatitis C with interferon-based compounds offers significant potential for clinical impact. Two separate compounds, peginterferon alfa-2a (PEGASYS) and peginterferon alfa-2b (PEG-Intron) are now both approved for use alone and in combination with ribavirin for the treatment of chronic hepatitis C. However, the different PEG moieties attached to the native protein, the site of attachment and the type of bond involved lead to vast differences with respect to the pharmacokinetics (including absorption, biodistribution, metabolism and elimination) and pharmacodynamics of these two compounds. This article discusses the differences that exist between these compounds, which may lead to different clinical profiles for their use in the treatment of patients with hepatitis C.

Simple sequence repeat analysis of a clonally propagated species: a tool for managing a grape germplasm collection.

The USDA germplasm repositories help to preserve the genetic variability of important crop species by collecting and maintaining representative cultivars and related germplasm. Simple sequence repeat markers with high allelic diversity were used to type 41 grapevines from 40 accessions. All vines were either seedless table grape cultivars or cultivars with names similar to table grape cultivars. The proportion of shared alleles was selected as the most appropriate statistical measure of genetic distance for this population. In conjunction with morphological traits, known synonyms were confirmed and a previously unknown synonym was discovered. An alleged synonym in the literature was disproved by the DNA data. The data were consistent with known parentage, where such data were available. Two mislabeled vines in the USDA collection were identified. UPGMA grouped the cultivars loosely into three groups: a group of nine mostly Middle Eastern cultivars, a group of 22 accessions mostly from Russia and Afghanistan that were morphologically similar to 'Thompson Seedless', and a third very loose group of 11 accessions consisting mostly of eastern European wine grape cultivars. The limitations and usefulness of this type of analysis are discussed.

Patients and profits: the relationship between HMO financial performance and quality of care.

This paper matches health plans' financial performance with information on quality ratings as measured by 1997 Health Plan Employer Data and Information Set (HEDIS) 3.0 data. We address three policy questions: (1) Is the quality of care delivered by a plan influenced by the plan's financial performance? (2) Do for-profit plans behave differently than nonprofits do? (3) What other factors are associated with variation in plan performance? We find, first, that more profitable plans achieve higher quality scores in subsequent years. Profits may enable a plan to pursue higher quality of care and invest in better management systems. Second, there is little systematic evidence that for-profit plans have different HEDIS scores than not-for-profits have.

The effect of managed care on the incomes of primary care and specialty physicians.

OBJECTIVE: To determine the effects of managed care growth on the incomes of primary care and specialist physicians. DATA SOURCES: Data on physician income and managed care penetration from the American Medical Association, Socioeconomic Monitoring System (SMS) Surveys for 1985 and 1993. We use secondary data from the Area Resource File and U.S. Census publications to construct geographical socioeconomic control variables, and we examine data from the National Residency Matching Program. STUDY DESIGN: Two-stage least squares regressions are estimated to determine the effect of local managed care penetration on specialty-specific physician incomes, while controlling for factors associated with local variation in supply and demand and accounting for the potential endogeneity of managed care penetration. DATA COLLECTION: The SMS survey is an annual telephone survey conducted by the American Medical Association of approximately one percent of nonfederal, post-residency U.S. physicians. Response rates average 60-70 percent, and analysis is weighted to account for nonresponse bias. PRINCIPAL FINDINGS: The incomes of primary care physicians rose most rapidly in states with higher managed care growth, while the income growth of hospital-based specialists was negatively associated with managed care growth. Incomes of medical subspecialists were not significantly affected by managed care growth over this period. These findings are consistent with trends in postgraduate training choices of new physicians. CONCLUSIONS: Evidence is consistent with a relative increase in the demand for primary care physicians and a decline in the demand for some specialists under managed care. Market adjustments have important implications for health policy and physician workforce planning.

Determinants of managed care penetration.

This paper examines factors associated with differences in managed care penetration across geographic areas. Two alternative measures of managed care penetration are considered: the percentage of revenue physicians received from managed care contracts and market survey data on enrollments in managed care plans. Results are similar for both types of measures. Our analysis suggests that demographics, labor market characteristics and supply side variables including the level of concentration in hospital markets, hospital occupancy rates and the practice organization patterns of physicians are all important determinants of managed care penetration.

The impact of managed care on the physician marketplace.

OBJECTIVE: To examine the impact of managed care on the employment and compensation of primary care and specialty physicians, as measured by changes in income, physician-to-population ratios, and specialty choices. METHODS: The authors used data from the American Medical Association's Socioeconomic Monitoring System survey, a nationally representative 1% random survey of post-residency patient-care physicians, and location data from the AMA Masterfile to evaluate the relationship between the growth in managed care from 1985 to 1993 and (a) inflation-adjusted physician incomes and (b) physician-to-population ratios for primary care physicians and specialists. They also used data from the National Residency Matching Program for 1989 through 1995 to look at trends in available positions and specialty choices. RESULTS: Primary care incomes grew 4.78% annually ($33,526 cumulatively) in states with the highest managed care growth, compared to 1.20% ($7448 cumulatively) in the lowest quartile of managed care growth. The difference in income growth for medical and surgical subspecialists between the highest and lowest quartiles was not statistically significant. The incomes of radiologists, anesthesiologists, and pathologists (RAPs) rose 0.14%, or $1700, in the highest quartile versus 4.14% ($58,558) in the lowest. Subspecialists per capita did not differ by quartile of managed care growth; but RAPs per capita increased fastest in states in the lowest quartile. Between 1989 and 1995, the number of family practice and pediatric residency positions that were filled rose 32%, while the number filled remained stable for medical and surgical subspecialists and the number of RAP positions filled fell 14%. CONCLUSIONS: The growth in managed care has been associated with significant changes in physician incomes and practice locations. Between 1985 and 1993, states with the fastest growth in managed care penetration saw the highest rate of growth in primary care physicians' income and the slowest rate of growth in RAP physicians' income. At the same time, the number of RAP physicians grew most rapidly in those states with the lowest rate of managed care growth. Finally, between 1989 and 1995, there was a dramatic increase in the number of primary care residency positions filled and a marked decrease in the number of RAP residency positions filled across the country.

The provision of primary care: does managed care make a difference?

Drawing on a nationally representative survey of physicians, this paper examines the extent to which physicians split their time between primary care and non-primary care activities and whether managed care makes a difference. We find that managed care does matter: Physicians have been narrowing their scope of practice, and the trend is linked to their involvement with managed care plans. These findings have implications for workforce policy and training, regulation of managed care contracting, and the quality of care.