Search

Real-Time Locating Systems (RTLS) have become an important supporting technology in manufacturing due to safety, logistical and managerial concerns. RTLS is a very wide term covering many different specific technologies. To increase the potential for implementation and better anticipate the costs associated, four different RTLS technologies have been evaluated according use case characteristics, maintenance costs, communication requirements. Data server capabilities, scalability, and integrability. The ability to analyze and determine such criteria are vital to support the selection of a specific technology (or mix of technologies) within manufacturing. The paper offers researchers and managers a reference comparison of the total costs surrounding the ownership of Ultra-wide band (UWB), Bluetooth Low Energy, Ultrasonic, and Optical RTLS technologies.

Two-dimensional (2D) beam profiling is an emerging technique used to characterize the beam homogeneity in dental light-curing units (LCUs). This project developed a method to combine multiple 2D beam profiles that had been measured along the beam path to create a 3D profile of the beam. This allowed a quantitative investigation of beam divergence and homogeneity at different distances from the source. To illustrate the use of this technique, four representative dental LCUs were measured. In addition, the selected dental LCUs demonstrated the effects of LCU design, particularly that of fiber optic light guides, on beam quality. The results show the value of a program that can recombine multiple beam profile images made at different distances from the source to create a 3D beam profile of a light beam.

Difficulties in social communication are part of the phenotypic overlap between autism spectrum disorders (ASD) and schizophrenia. Both conditions follow, however, distinct developmental patterns. Symptoms of ASD typically occur during early childhood, whereas most symptoms characteristic of schizophrenia do not appear before early adulthood. We investigated whether overlap in common genetic influences between these clinical conditions and impairments in social communication depends on the developmental stage of the assessed trait. Social communication difficulties were measured in typically-developing youth (Avon Longitudinal Study of Parents and Children, N⩽5553, longitudinal assessments at 8, 11, 14 and 17 years) using the Social Communication Disorder Checklist. Data on clinical ASD (PGC-ASD: 5305 cases, 5305 pseudo-controls; iPSYCH-ASD: 7783 cases, 11 359 controls) and schizophrenia (PGC-SCZ2: 34 241 cases, 45 604 controls, 1235 trios) were either obtained through the Psychiatric Genomics Consortium (PGC) or the Danish iPSYCH project. Overlap in genetic influences between ASD and social communication difficulties during development decreased with age, both in the PGC-ASD and the iPSYCH-ASD sample. Genetic overlap between schizophrenia and social communication difficulties, by contrast, persisted across age, as observed within two independent PGC-SCZ2 subsamples, and showed an increase in magnitude for traits assessed during later adolescence. ASD- and schizophrenia-related polygenic effects were unrelated to each other and changes in trait-disorder links reflect the heterogeneity of genetic factors influencing social communication difficulties during childhood versus later adolescence. Thus, both clinical ASD and schizophrenia share some genetic influences with impairments in social communication, but reveal distinct developmental profiles in their genetic links, consistent with the onset of clinical symptoms.

This investigation utilizes surface plasmon resonance (SPR) spectroscopy to detect and quantify human epidermal growth factor receptor 2 (HER-2), an oncogene product that is over-expressed in some aggressive forms of breast cancer. Specifically, the HER-2 trans-membrane protein p185 and its extra cellular fragment p105 are analytes targeted in this work by using a gold-based biosensor slide on which an anti-HER-2 antibody has been immobilized by attachment to Protein G that is fixed to the gold film. A detection limit of ≥11 ng/mL for p185 resulted when trastuzumab was used as the anti-HER-2 antibody on the biosensor slide. Experiments with semi-purified p105 revealed that it binds weakly and reversibly to trastuzumab, therefore complicating its detection and quantification. Results of studies that reacted a 13-amino-acid peptide (PP13) from the HER-2 kinase domain with its specific antibody were critically different than p185 and p105 studies. Spectral analysis of the reflectivity at constant bulk buffer refractive index revealed a progressive negative SPR shift over time. A negative shift suggests that a loss of protein mass from the anti-PP13 antibody–Protein G biosensor is occurring. Several possibilities that may explain these negative SPR shifts are discussed.

Neuroticism is a personality trait of fundamental importance for psychological well-being and public health. It is strongly associated with major depressive disorder (MDD) and several other psychiatric conditions. Although neuroticism is heritable, attempts to identify the alleles involved in previous studies have been limited by relatively small sample sizes. Here we report a combined meta-analysis of genome-wide association study (GWAS) of neuroticism that includes 91 370 participants from the UK Biobank cohort, 6659 participants from the Generation Scotland: Scottish Family Health Study (GS:SFHS) and 8687 participants from a QIMR (Queensland Institute of Medical Research) Berghofer Medical Research Institute (QIMR) cohort. All participants were assessed using the same neuroticism instrument, the Eysenck Personality Questionnaire-Revised (EPQ-R-S) Short Form’s Neuroticism scale. We found a single-nucleotide polymorphism-based heritability estimate for neuroticism of ∼15% (s.e.=0.7%). Meta-analysis identified nine novel loci associated with neuroticism. The strongest evidence for association was at a locus on chromosome 8 (P=1.5 × 10−15) spanning 4 Mb and containing at least 36 genes. Other associated loci included interesting candidate genes on chromosome 1 (GRIK3 (glutamate receptor ionotropic kainate 3)), chromosome 4 (KLHL2 (Kelch-like protein 2)), chromosome 17 (CRHR1 (corticotropin-releasing hormone receptor 1) and MAPT (microtubule-associated protein Tau)) and on chromosome 18 (CELF4 (CUGBP elav-like family member 4)). We found no evidence for genetic differences in the common allelic architecture of neuroticism by sex. By comparing our findings with those of the Psychiatric Genetics Consortia, we identified a strong genetic correlation between neuroticism and MDD and a less strong but significant genetic correlation with schizophrenia, although not with bipolar disorder. Polygenic risk scores derived from the primary UK Biobank sample captured ∼1% of the variance in neuroticism in the GS:SFHS and QIMR samples, although most of the genome-wide significant alleles identified within a UK Biobank-only GWAS of neuroticism were not independently replicated within these cohorts. The identification of nine novel neuroticism-associated loci will drive forward future work on the neurobiology of neuroticism and related phenotypes.

AbstractSeabird mortality in longline fishing has been implicated in the decline of many populations around the world. The population of the Black-browed Albatross breeding in the Falkland Islands has been estimated to have declined by 87500 pairs between 1995 and 2000. The observed mortality in the Patagonian Toothfish longline fishery in Falkland Islands waters in 2001–02 was 29 seabirds, including 27 Black-browed Albatrosses, giving an estimated total mortality of 134 (95% confidence limits 80–188) birds, including 126 (75–177) Black-browed Albatrosses. This suggests that this fishery in Falkland Islands waters is currently not contributing substantially to observed declines in the local populations. Nevertheless, mortality could be further reduced by night setting and an increase in line weighting, especially during the breeding season of the Black-browed Albatross.

Ovipositing female Nantucket pine tip moth, Rhyacionia frustrana, prefer loblolly pine, Pinus taedaL., to slash pine, Pinus elliottiiEngelm. except during the first spring following planting of seedlings. Host discrimination by R. frustranaincreases as seedlings develop, suggesting that changes in the chemical composition of seedlings may mediate the moth's host preferences. Volatile compounds from slash and loblolly pine seedlings were collected using solid-phase microextraction (SPME) during the first year following planting. Four collection periods coincided with adult emergence and oviposition during each of four annual generations of R. frustranain the Georgia Coastal Plain. Infestation of slash pine peaked during the second tip moth generation and was similar to the loblolly pine infestation level. By the fourth tip moth generation, slash pine infestation levels had declined and diverged considerably from those of loblolly pine. Significant differences in relative quantities of β-pinene, α-phellandrene, limonene, β-phellandrene, bornyl acetate, β-caryophyllene, and an unidentified sesquiterpene occurred between slash and loblolly pine during the fourth generation. However, no strong correlation was observed between any individual compound and host damage that could readily explain the temporal changes in R. frustranahost preference. Gas chromatographic–electroantennographic detection (GC–EAD) analyses of standards identified 19 different seedling- associated compounds that elicited antennal responses from R. frustranafemales, indicating that a blend of terpenoids may mediate host discrimination.

Seabird mortality in longline fishing has been implicated in the decline of many populations around the world. The population of the Black-browed Albatross breeding in the Falkland Islands has been estimated to have declined by 87 500 pairs between 1995 and 2000. The observed mortality in Patagonian Toothfish longline fishery in Falkland Islands waters in 2001–02 was 29 seabirds, including 27 Black-browed Albatrosses, giving an estimated total mortality of 134 (95% confidence limits 80–188) birds, including 126 (75–177) Black-browed Albatrosses. This suggests that this fishery in Falkland Islands waters is currently not contributing substantially to observed declines in the local populations. Nevertheless, mortality could be further reduced by night setting and an increase in line weighting, especially during the breeding season of the Black-browed Albatross.

A multilayered biosensor was constructed and found to detect trinitrotoluene (TNT) in ppb concentrations in air both prior to and after detonation of TNT without use of a liquid phosphate buffered saline (PBS) superstrate. The biosensor surface was fabricated from a monoclonal antibody for TNT covalently bound to an 11,11′-dithio-bis(succinimidoylundecanoate) (DSU) self-assembled monolayer immobilized on a thin gold film bonded to a BK7 glass slide. The binding between the immobilized antibody and TNT antigen was detected using surface plasmon resonance spectroscopy (SPRS). Biosensor specificity for TNT was demonstrated with chemical homologues as well as against an unrelated explosive, RDX.

Y-tube olfactometer bioassays and combined gas chromatography–electroantennographic detector (GC-EAD) analyses were performed to investigate the specific odors utilized as host location cues by the bark beetle parasitoid, Roptrocerus xylophagorum, originating from the southeastern United States. R. xylophagorumparasitizes several economically important holarctic bark beetle species and females oviposit preferentially on late larval stages. Both female and male parasitoids were tested with volatiles derived from host infestations of either Dendroctonus frontalis, the southern pine beetle, or Ips grandicollis, the southern pine engraver. Tested volatiles were steam distillates from the bark of loblolly pine, Pinus taeda, infested with larvae of the respective bark beetle species. Combined gas chromatography–mass spectrometry (GC-MS) was employed for identification and quantification of the compounds in the steam distillates. To confirm the EAD activity of identified compounds, GC-EAD analyses were repeated with a synthetic blend composed predominantly of compounds in the crude extracts that had revealed apparent electrophysiological activity. In Y-olfactometer bioassays, female parasitoids were attracted to both of the above-mentioned distillates. Male parasitoids were tested with one of the distillates but failed to respond. In GC-EAD analyses, the sexes displayed similar relative sensitivities to the components of the blends. Males exhibited generally higher amplitudes of response to the tested compounds than females. Monoterpene hydrocarbons associated with the constitutive resin of the host tree did not elicit significant EAD responses. Compounds known to be associated specifically with the host–tree complex, such as certain oxygenated monoterpenes, generated the greatest EAD responses. Female parasitoids were attracted by a synthetic blend composed of several of the EAD active oxygenated monoterpenes.

The X1A soft X‐ray undulator beamline at the NSLS has been rebuilt to serve two microscopy stations operating simultaneously. Separate spherical‐grating monochromators provide the resolving power required for XANES spectroscopy at the C, N and O absorption edges. The exit slits are fixed and define the coherent source for the experiments. The optical design and the operational performance are described.

COPI, a protein complex consisting of coatomer and the small GTPase ARF1, is an integral component of some intracellular transport carriers. The association of COPI with secretory membranes has been implicated in the maintenance of Golgi integrity and the normal functioning of intracellular transport in eukaryotes. The regulator of G protein signaling, RGS4, interacted with the COPI subunit beta'-COP in a yeast two-hybrid screen. Both recombinant RGS4 and RGS2 bound purified recombinant beta'-COP in vitro. Endogenous cytosolic RGS4 from NG108 cells and RGS2 from HEK293T cells cofractionated with the COPI complex by gel filtration. Binding of beta'-COP to RGS4 occurred through two dilysine motifs in RGS4, similar to those contained in some aminoglycoside antibiotics that are known to bind coatomer. RGS4 inhibited COPI binding to Golgi membranes independently of its GTPase-accelerating activity on G(ialpha). In RGS4-transfected LLC-PK1 cells, the amount of COPI in the Golgi region was considerably reduced compared with that in wild-type cells, but there was no detectable difference in the amount of either Golgi-associated ARF1 or the integral Golgi membrane protein giantin, indicating that Golgi integrity was preserved. In addition, RGS4 expression inhibited trafficking of aquaporin 1 to the plasma membrane in LLC-PK1 cells and impaired secretion of placental alkaline phosphatase from HEK293T cells. The inhibitory effect of RGS4 in these assays was independent of GTPase-accelerating activity but correlated with its ability to bind COPI. Thus, these data support the hypothesis that these RGS proteins sequester coatomer in the cytoplasm and inhibit its recruitment onto Golgi membranes, which may in turn modulate Golgi-plasma membrane or intra-Golgi transport.

Summary:  Objective. Cardiopulmonary bypass with profound hypothermia and circulatory arrest has seen a resurgence as an adjunct technique in neurological surgery. We report our experience with this technique in treating seven complex vertebro-basilar aneurysms.  Methods. Skull base approaches were used in all cases, providing excellent exposure and minimizing brain retraction. There were six basilar artery aneurysms and one giant fusiform vertebro-basilar artery aneurysm. All aneurysms but one had an apparent neck, which could be clipped. The fusiform vertebro-basilar artery aneurysm was trapped, partially resected, and the circulation was re-established with a saphenous vein graft from the cervical internal carotid artery to the mid-basilar artery.  Results. Five patients had an excellent outcome and two had a good outcome at one year or at latest follow up. Two of the patients showed improvement of neurological deficits which were present before the surgical intervention.  Conclusion. Applying very strict selection criteria in this small series of patients with posterior circulation aneurysms, excellent or good results were achieved using the profound hypothermic circulatory arrest technique.

Abstract: Objective. To determine the accuracy of MRI in the assessment of the radiographically occult scaphoid fracture. Design. This prospective study compared the sensitivity and specificity of MRI for detection of radiographically occult scaphoid fractures with bone scintigraphy (BS), the currently accepted imaging modality of choice. Consecutive patients with clinical signs of a scaphoid injury but no evidence of fracture on plain radiographs at presentation and after 7–10 days were evaluated by MRI and BS. All images were reported in masked fashion and the sensitivities and specificities of the imaging modalities determined. All patients with a scaphoid fracture demonstrated by MRI or BS were followed for at least a year after injury. Patients. Forty-three subjects (aged 12–74 years) had both MRI and BS carried out on average 19 days from the injury date. Results and conclusions. Six patients (14%) had scaphoid waist fractures. There were other bony injuries in a further six. In 40 patients there was agreement between the BS and MRI findings. In three cases there was discrepancy between the imaging modalities; in all three MRI was found to be the more sensitive and specific. MRI could become the investigation of choice for this injury.

Studies were performed to isolate and identify semiochemicals that mediate location of host-infested trees by parasitoids of the southern pine beetle (SPB), Dendroctonus frontalis. Bark or bolts removed from pines infested with SPB broods attracted significant numbers of the hymenopterous parasitoids Spathius pallidusand Roptrocerus xylophagorumto sticky traps placed in an active SPB infestation. Traps baited with the water distillate of SPB brood-infested bark also attracted both species of parasitoids. In contrast, a synthetic bait composed of 18 compounds identified from the headspace volatiles of attractive bark failed to trap parasitoids. The oxygenated and hydrocarbon components of the bark distillate were partitioned by silica gel liquid chromatography, and the resulting two fractions were tested in the field. Parasitoid attraction was greatest when both fractions were released from traps simultaneously. The hydrocarbon fraction, which failed to attract parasitoids, enhanced the weak attractiveness of the oxygenated fraction. Hence, it appears that no single compound is responsible for mediating SPB parasitoid host-tree location and that both oxygenated and hydrocarbon semiochemicals are involved in this process.

The late fall planting season for rye in the southeastern USA is typically characterized by an extreme range of temperature conditions. The potential for selection of diploid and tetraploid rye (Secale cerealeL.) populations possessing superior seedling growth characters over a broad range of temperatures was assessed by examining the effect of genetic background on various seeding growth characters at three temperatures (12, 20, 28°C). Diploid populations, and their colchicine‐derived tetraploid counterparts from five genetic backgrounds (‘Elbon’, ‘Explorer’, ‘Florida Black’, ‘Gator’, ‘Wrens Abruzzi’) were compared. The seedling characters included shoot and primary root growth day−1, root cross‐sectional area at the meristematic region, and primary root bluntness ratio (distance from the plane of maximum root diameter at the meristematic region to the root tip divided by the maximum root diameter at the meristematic region). Highly significant ploidy level (PL), genetic background (GB), and temperature (T) main effects were obtained for both shoot and primary root growth day−1. A highly significant T✕GB✕PL interaction was found for shoot growth day−1, but this effect was not significant for root growth day−1. The T ✕ PL interaction was significant for primary root growth day−1at the 0.05 level. Highly significant ploidy level (PL) and temperature (T) main effects were obtained for root cross‐sectional area. A highly significant ploidy level (PL) main effect was found for the bluntness ratio. The lower ratios obtained for the tetraploid populations indicated that the tetraploid root tips were blunter than those of diploids, which may be a factor in soil penetration and root proliferation. The results indicated that substantial genetic variation for seedling growth characters was present among genetic backgrounds as well as within populations at both ploidy levels over a wide temperature range. It was concluded that selection for diploid as well as tetraploid rye populations possessing superior seedling growth characters over a broad range of temperatures would be successful.

Thirty-five pancreatograms were selected from 62 which were obtained during endoscopic cannulation of the papilla of Vater with retrograde injection of radiopaque medium. Pancreatograms were selected on the basis of the quality of the study and on the absence of any clinically demonstrable pancreatic disease. Measurements were made of the main pancreatic duct (MPD) in the head, body, and tail, as well as the length of the duct. Althought there is a wide range of normal, practical reference figures for the diameters of the main duct in the head, body, and tail are 3, 2, and 1 mm, respectively. The length averages 15.4 cm. No correlation was found between the measurements and the body surface area, age, or sex of the patient. Comparisons are made with other autopsy and endoscopic studies, and attention is focused on the salient anatomic features, including normal points of narrowing of the duct, the accessory pancreatic duct (APD), and the main pancreatic duct branches (MPDB).

Emission from thin films of poly[Ru(vbpy)3](PF6)2 (vbpy = 4-methyl-4‘-vinyl-2,2‘-bipyridine) prepared by reductive electropolymerization on ITO (Sn:In2O3) is dominated by time-dependent effects and dramatically reduced excited state lifetimes compared to related monomers. The origins of these effects have been investigated by photophysical measurements on a series of copolymeric films containing mixtures of the Zn^II, Ru^II, and Os^II forms of poly[M(vbpy)3](PF6)2. In copolymeric Ru^II and Os^II films, facile energy transfer occurs from Ru^II to Os^II. Dilution of Ru^II by Zn^II in copoly-χ[Ru(vbpy)3](PF6)2,(1 − χ)[Zn(vbpy)3](PF6)2 (χ = mole fraction of Ru^II) mixtures is accompanied by an increase in emission energy and average excited state lifetime. These results point to a quenching mechanism in poly[Ru(vbpy)3](PF6)2 arising from facile energy transfer to low-energy, short-lived “trap sites”. The trap sites may be created by electronic coupling between special pairs of adjacent complexes present in small amounts. The decrease in excited state lifetime at the trap sites is predicted qualitatively by the energy gap law for nonradiative decay.

This study determined whether HLA-DR was incorporated into human immunodeficiency virus type 1 produced in vivo or by primary cultured cells. HLA-DR was associated with virions from primary isolates, macrophage cultures, and blood plasma. These results represent the first demonstration of major histocompatibility complex molecules associated with an in vivo source of virus.

This study examines the application of population statistics to laboratory-derived toxicological data for the purpose of developing a predictive model that assesses the population consequences of pollutant and environmentally-induced stress. Life tables are used to calculate age-specific survivorship, fecundity, intrinsic rate of population increase (r), and reproductive value (Va), for populations ofMysidopsis bahia chronically exposed, in separate tests, to mercury and nickel. The population statistics, r, and Va, and pollutant dose are defined quantitatively, and the critical value (r = 0) for the intrinsic rate of population increase is compared with traditional toxicological measures of acute and chronic toxicity.

The requirement of field pea (Pisum sativum) for seed inoculation with Rhizobium and for lime pelleting of inoculated seed was investigated in field experiments in the south-west of Western Australia, especially at locations where inoculated field pea had been grown 2 years previously. At most sites with previous pea cropping, the nodulation, total dry matter and nitrogen, and grain yield of pea were not improved by seed inoculation or lime pelleting. At these sites soil populations of R. leguminosarum by. viciae at sowing were >103/g soil. Responses to inoculation were measured at sites where the soil was very acidic [pH(CaCl2) <4.5], or mildly acidic (to pH 4.9) and of light texture (>90% sand + gravel), or where pea had not grown previously. There were fewer rhizobia at sowing at these locations. Lime pelleting was not generally required to maximise field pea growth or yield, but yield was affected by the inoculant Rhizobium strain.

The members of a recently identified protein family termed regulators of G-protein signaling (RGS) act as GTPase-activating proteins for certain Galpha subunits in vitro, but their physiological effects in cells are uncertain in the face of similar biochemical activity and overlapping patterns of tissue expression. Consistent with its activity in in vitro GTPase-activating protein assays, RGS4 interacts efficiently with endogenous proteins of the Gi and Gq subclasses of Galpha subunits but not with G12alpha or Gsalpha. Unlike other RGS proteins such as RGS9, RGS-GAIP, and Sst2p, which have been reported to be largely membrane-associated, a majority of cellular RGS4 is found as a soluble protein in the cytoplasm. However, the expression of a GTPase-deficient Gialpha subunit (Gialpha2-Q204L) resulted in the translocation of both wild type RGS4 and a non-Gialpha-binding mutant (L159F) to the plasma membrane. These data suggest that RGS4 may be recruited to the plasma membrane indirectly by G-protein activation and that multiple RGS proteins within a given cell might be differentially localized to determine a physiologic response to a G-protein-linked stimulus.

Millimeter-wave mixers using Josephson point contacts are described, which exhibit a conversion loss L/sub c/ = 9.5 dB and a noise temperature T ~ 223 K for lambda >or= 0.95 mm. Their potentials and limitations in noise, bandwidth, drive power, and stability for receiver applications are discussed.

Elevated expression of the receptor for epidermal growth factor (EGF) is a characteristic of several malignancies including those of the breast, bladder, prostate, lung, and neuroglia. To therapeutically target the cytotoxic action of diphtheria toxin to EGF receptor-expressing tumor cells, we have constructed a hybrid gene in which the sequences for the binding domain of diphtheria toxin have been replaced by those for human EGF. The resulting fusion toxins, DAB486EGF and DAB389EGF, bind specifically to the EGF receptor and inhibit protein synthesis in a variety of EGF receptor expressing human tumor cell lines with an IC50 as low as 0.1 pM. Comparisons of DAB486EGF and DAB389EGF showed that DAB389EGF was consistently 10- to 100-fold more cytotoxic than DAB486EGF. Like diphtheria toxin, the cytotoxic action of DAB389EGF results from ADP-ribosylation of elongation factor-2 and is sensitive to the action of chloroquine. Studies of the kinetics of cellular intoxication showed that a 15-min exposure of EGF receptor-expressing A431 cells to DAB389EGF results in complete protein synthesis inhibition within 4 h. Furthermore, inhibition of protein synthesis results in elimination of human tumor cell colonies. These findings show that DAB389EGF is a potential therapeutic agent for a wide variety of EGF receptor-expressing solid tumors.

The rate equation method is used to determine the large displacement static and dynamic response of viscoelastic shells of revolution. Among the results presented are those for which the effects of changes in the dimension of lineal elements through the thickness of the shell have been included. This effect has been incorporated within the confines of a structural theory, and full nonlinear shell equations are used to perform the analyses. Both the accuracy and economy of the rate equation method applied to problems of this nature are demonstrated through comparisons of solutions obtained by other methods.

Aortoduodenal fistula has been reported as a complication in up to 4% of aortic aneurysm repairs, presenting as gastrointestinal bleeding of varying severity. Mortality of patients not operated on approaches 100%, and preoperative diagnosis is extremely difficult. In this report five cases are described in which the diagnosis was established endoscopically, and the literature regarding the pathophysiology and natural history of this entity is reviewed.

A total of 137 polyps were removed during 106 colonoscopies on 100 patients. In one patient there was significant colonic bleeding. Another patient was hospitalized with the delayed onset of abdominal pain in the general area of the polypectomy. This complication has not been reported previously and was presumed to be serositis due to a transmural burn. Average age of the patients was 57 years. Most were men. Twenty-four procedures were multiple polypectomies. Most polyps were in the sigmoid or descending colon. At microscopy 116 polyps showed a variety of pathologic types, including one invasive and nine superficial carcinomas. Several small polyps disclosed superficial cancer. Nine patients had histories of colon cancer of “malignant polyp.” Presenting features included bleeding or polyp(s) found at routine sigmoidoscopy or barium enema. The accuracy of barium enema in detecting polyps was 76%.