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ABSTRACTJune-Wells M, Simpkins T, Coleman AM, Henley W, Jacobs R, Aarrestad P, Buck G, Stevens C, Benson G. 2017. Seventeen years of grass carp: an examination of vegetation management and collateral impacts in Ball Pond, New Fairfield, Connecticut. Lake Reserve Manage. 33:84–100.Ball Pond is a 32 ha meso-eutrophic lake located in the Marble Valley of Connecticut. The local bedrock geology and watershed influences have resulted in a hardwater system with limited plant community diversity and an assemblage dominated by the nonnative species Myriophyllum spicatum. By 1996, M. spicatumdominated 32% of the waterbody, and residents were concerned their property values would fall as the recreational value of the lake diminished. In an attempt to remedy this issue, 400 grass carp (Ctenopharyngodon idella; ∼30 cm length) were released in 1997 at a rate of 38 per vegetated hectare. As a requirement of the state permit, the plant community, water quality, and the fish community were monitored throughout the initiative (1997–2014) to examine the impact of grass carp at multiple ecological levels of the lentic system. M. spicatumwas significantly reduced in biomass and cover between 1997 and 2014, with no change in plant community richness. Concordant with the decrease in M. spicatum, the cover of Ceratophyllum demersumincreased significantly and became more dominant in the plant community as M. spicatumwas reduced. Our results also suggest there was no change in water quality or fish community density/diversity during the study period; however, fish community richness was reduced. Bluegill (Lepomis macrochirus) density and largemouth bass (Micropterus salmoides) size distribution both increased during this study. We assert that grass carp can be an effective approach to nonnative plant management in a northern meso-eutrophic lake.

ABSTRACTJune-Wells M, Gallagher F, Hart B, Malik V, Bugbee G. 2016. The relative influences of fine and landscape scale factors on the structure of lentic plant assemblages. Lake Reserv Manage. 32:116–131.The process of plant community assembly has long been a topic of debate among ecologists. Aquatic plant assemblages and their structure may be the result of a series of abiotic and biotic filters that include transport (i.e., physical movement of species), water chemistry, sediment chemistry, basin structure, and competitive interactions. The influences of transport and water chemistry have been well investigated, but many questions persist about the interrelationships among water and sediment variables, including their combined influences on the structure of the aquatic plant assemblage. To understand how these abiotic conditions interact, we sampled 750 points in 30 lakes. Using these data, a split canonical correspondence design was used to evaluate the relative influences of regional and fine-scale conditions in structuring the plant assemblage. Additionally, multiple logistic regressions were employed to determine the individual species’ abiotic preferences. The results suggest that the plant assemblage structure is principally determined by the lake-sediment characteristics. Sediment variables explained 28% of the total species-data variance and water chemistry accounted for 9% (total variance explained = 46%; 9% due to intercorrelation of water/sediment characteristics). There were also strong species–environmental relationships; nonnative species showed distinct correlations with sediment pH and lake water conductivity, which may be useful in lake management initiatives such as risk assessment and nonnative species monitoring. Finally, and as expected, the Shannon diversity index was strongly related to depth and light.

Mariculture and recreational zones are expanding rapidly along the coast of Primorsky Krai in the Russian Far East, increasing the pressing need for monitoring of toxin-producing algae and seafood poisoning. One poisoning syndrome, diarrhetic shellfish poisoning has not been reported in this region, but its expansion to other subarctic waters has been observed. To our knowledge, the research here shows the first measures of diarrhetic shellfish toxins (DST) on the east coast of Russia. Mussels contained DST concentrations above the recommended regulatory level of 16 mg/100 g shellfish at almost all sites sampled in the Primorsky Krai region, with maximum concentrations of 56.3 mg/100 g. The primary DST isoform was dinophysistoxin-1 (DTX-1; 94%-100%) but minor amounts of okadaic acid (0%-6%) also were detected. Other lipophilic toxins measured in shellfish were yessotoxin , pectenotoxin-2 (PTX-2), and azaspiracid-2; the last two toxins observed in Russian water for the first time. Phytoplankton samples dominated by Dinophysis acuminata contained DST, indicating that it was likely responsible for shellfish toxicity. Particulate seawater samples with Dinophysis contained 2.1-10.2 ng DTX-1/l and 6.5-101.8 ng PTX-2/l, corresponding to cellular concentrations of 3.1-5.6 pg DTX-1/cell and 9.6-46.7 pg PTX-2/cell. These findings provide a foundation for a Federal Monitoring Program for harmful algal blooms and phycotoxin control in seafood in Russia, and suggest that appropriate methods for both rapid screening and regulation of shellfish toxins should be established to ensure safe harvest in Russia. [ABSTRACT FROM AUTHOR]

AbstractOur analysis of 156 lakes and 5 nonnative aquatic macrophyte species suggest that 4 water chemistry variables can be used to assess the risk associated with species invasion in Connecticut lakes. Our analysis showed that water chemistry and longitude explained a significant amount of the total data variance (33%). Additionally, individual species logistic regressions suggest that these species’ distributions were determined by the specific conductance and pH of the water body. Lakes were then placed into one of the following groups: (1) Cabomba caroliniana/ Myriophyllum heterophyllum(CM), (2) Myriophyllum spicatum/Najas minor/Potamogeton crispus(MNP), (3) Mixed (Mixed), or (4) No Invasive (NI). Multivariate analysis of variance suggests that water chemistry of the groups CM and MNP differed significantly (p < 0.001), and the variables that contributed to this difference were specific conductance (F = 22.16), alkalinity (F = 19.40), and pH (F = 18.61). The Mixed and No Invasive groups were not significantly different. Discriminant function analysis was used as a final analytical tool to determine the risk of NI group lakes developing populations of our nonnative species. The results suggest that the 4 abiotic variables could predict the identity of the CM and MNP groups with a high degree of certainty (i.e., 79 and 71% correct, respectively). When the NI group was included in the discriminant analysis, 34% of these lakes were grouped with CM and 14% with MNP. The remaining 52% of NI lakes had water chemistry parameters capable of supporting all species examined in this study. From these findings, water chemistry risk assessment ranges were developed for these common nonnative species in Connecticut.

AbstractThe aquarium trade has been shown to be a source for introductions of nonnative aquatic macrophyte species. Improvements are needed in identification, labeling, and retailer awareness of banned aquatic plants. In the state of Connecticut, United States, 20 nonnative macrophytes are banned from sale by state statute. At least 13 of these species are already established in the state's lakes, while the remainder are either present in near-shore wetlands or absent but thought to be capable of naturalizing. We documented the sale of banned plants in the Connecticut aquarium trade by visiting 23 retailers in 2008 and 47 retailers in 2010. Plants that resembled Connecticut's banned species were purchased and identified using standard morphological techniques. In 2010, we also employed DNA sequencing to aid in plant identification. We found that nearly 30% of stores sold banned aquatic plants including Cabomba caroliniana, Egeria densa, Myriophyllum aquaticum, and Myriophyllum heterophyllum. Cabomba carolinianarepresented more than half of the banned species being sold; it was found in 17% of the stores in 2008 and 19% of the stores in 2010. Egeria densawas mislabeled 50% of the time as Egeria najasor Anacharis najas; it was sold in 11% of the stores in 2008 and 17% of the stores in 2010. In 2010, Myriophyllumspecimens from 6 stores were unidentifiable using morphological characteristics. Using these techniques, one of the specimens was identified as Myriophyllum heterophyllum. Of the 29 chain stores surveyed, 7% sold banned species compared to 56% of the 27 independent stores.

In September 2004 a large, nearly monospecific diatom bloom of Pseudo‐nitzschia cuspidata off the coast of the state of Washington reached cell concentrations of 6.1 × 106cells L−1and produced maximum particulate domoic acid (pDA), dissolved domoic acid (dDA), and cellular domoic acid concentrations of 43 nmol L−11, 4 nmol L−1, and 63 pg cell−1, respectively. This bloom co‐dominated the phytoplankton assemblage with the euglenoid Eutreptiella sp. in the Juan de Fuca eddy region, a known initiation site for toxigenic Pseudo‐nitzschiablooms. Two isolates of P. cuspidatacollected during separate cruises produced domoic acid (DA) in culture. During the September 2004 survey, 84% of the stations (n = 98) had detectable Pseudo‐nitzschiaand 78% had detectable pDA. There were no significant correlations between either pDA or cellular DA and ambient concentrations of macronutrients; however, when considering only those stations where Pseudo‐nitzschiawas present, pDA was positively correlated with chlorophyll a and negatively correlated with temperature (p ≪ 0.01) at both 1‐ and 5‐m depths. Correlations between cellular DA concentrations and total bacteria or cyanobacteria abundances were not significant. Variable ratios of pDA:dDA in the eddy region suggest that DA release was under cellular regulation by Pseudo‐nitzschia. Stations where dissolved Fe concentrations were limiting (,0.5 nmol L−1) had the highest Pseudo‐nitzschiaabundances and pDA and cellular DA values. These results provide enticing field evidence of the role of Fe limitation in controlling cellular DA levels.

The distribution of dissolved iron(II) [Fe(II)] was studied in surface waters of the western subarctic Pacific during the Subarctic Pacific Iron Experiment for Ecosystem Dynamics Study‐II (SEEDS II) iron enrichment experiment using highly sensitive flow injection‐based luminol chemiluminescence. Vertical profiles of Fe(II) and total dissolved iron were measured outside of the fertilized patch to investigate the chemical speciation of iron in this high‐nitrate low‐chlorophyll (HNLC) region. Ambient total dissolved iron concentrations ranged from 50 pmol L−1to 150 pmol L−1depending on depth and sampling times. Unexpectedly, Fe(II) accounted for up to half of total dissolved iron, with concentrations up to ~50 pmol L−1. Fe(II) concentrations decreased exponentially with depth and were undetectable at depths below 50 m. There was no evidence of increased Fe(II) concentrations associated with the subsurface chlorophyll maximum, indicating that photolysis, rather than biological reduction of Fe(III), was the primary source of Fe(II). Because Fe(II) concentrations in the fertilized patch remained elevated for more than a week after enrichment, Fe(II) oxidation rates at near‐ambient concentrations were measured. Indeed, the temperature‐dependent Fe(II) oxidation rates were significantly slower than predicted by Fe(II) oxidation models and rates measured in ligand‐free seawater. These findings suggest that Fe(II) binding ligands may exist in these HNLC waters, with conditional stability constants on the order of 108‐ 109with respect to Fe2+. The accumulation of Fe(II) during daylight hours did not alleviate iron limitation of eukaryotic phytoplankton in these waters, contrary to expectations from recent iron uptake models.

Although the physiological function of the prion protein remains unknown, in vitro experiments suggest that the protein may bind copper (II) ions and play a role in copper transport or homoeostasis in vivo. The unstructured N-terminal region of the prion protein has been shown to bind up to six copper (II) ions, with each of these ions co-ordinated by a single histidine imidazole and nearby backbone amide nitrogen atoms. Individually, these sites have micromolar affinities, which is weaker than would be expected of a true cuproprotein. In the present study, we show that with subsaturating levels of copper, different forms of co-ordination will occur, which have higher affinity. We have investigated the copper-binding properties of two peptides representing the known copper-binding regions of the prion protein: residues 57–91, which contains four tandem repeats of the octapeptide GGGWGQPH, and residues 91–115. Using equilibrium dialysis and spectroscopic methods, we unambiguously demonstrate that the mode of copper co-ordination in both of these peptides depends on the number of copper ions bound and that, at low copper occupancy, copper ions are co-ordinated with sub-micromolar affinity by multiple histidine imidazole groups. At pH 7.4, three different modes of copper co-ordination are accessible within the octapeptide repeats and two within the peptide comprising residues 91–115. The highest affinity copper (II)-binding modes cause self-association of both peptides, suggesting a role for copper (II) in controlling prion protein self-association in vivo.

It has been shown previously that the unfolded N-terminal domain of the prion protein can bind up to six Cu2+ ions in vitro. This domain contains four tandem repeats of the octapeptide sequence PHGGGWGQ, which, alongside the two histidine residues at positions 96 and 111, contribute to its Cu2+ binding properties. At the maximum metal-ion occupancy each Cu2+ is co-ordinated by a single imidazole and deprotonated backbone amide groups. However two recent studies of peptides representing the octapeptide repeat region of the protein have shown, that at low Cu2+ availability, an alternative mode of co-ordination occurs where the metal ion is bound by multiple histidine imidazole groups. Both modes of binding are readily populated at pH 7.4, while mild acidification to pH 5.5 selects in favour of the low occupancy, multiple imidazole binding mode. We have used NMR to resolve how Cu2+ binds to the full-length prion protein under mildly acidic conditions where multiple histidine co-ordination is dominant. We show that at pH 5.5 the protein binds two Cu2+ ions, and that all six histidine residues of the unfolded N-terminal domain and the N-terminal amine act as ligands. These two sites are of sufficient affinity to be maintained in the presence of millimolar concentrations of competing exogenous histidine. A previously unknown interaction between the N-terminal domain and a site on the C-terminal domain becomes apparent when the protein is loaded with Cu2+. Furthermore, the data reveal that sub-stoichiometric quantities of Cu2+ will cause self-association of the prion protein in vitro, suggesting that Cu2+ may play a role in controlling oligomerization in vivo.

Necrotizing fasciitis is a life-threatening, fulminant disease that is a diagnostic and therapeutic challenge. Presenting with a triad of findings including progressive erythema, severe dermatological edema and severe pain disproportionate to the physical findings, this disease is a surgical emergency. Delayed diagnosis and surgical debridement lead to higher mortality. Early extensive surgical debridement, aggressive antibiotic therapy, invasive monitoring and intensive care management determine the outcome in most cases. In patients who fail to demonstrate clinical improvement, profound sepsis and its sequela – systemic inflammatory response – have frequently been implicated. It is these patients that need to be carefully re-evaluated for hidden’ foci of infection that may be the real cause of the patient's decline. Once detected, these occult foci can be surgically debrided, resulting in dramatic improvement. Two illustrative cases, one with occult endo- and panophthalmitis and the other with an unusual involvement of deeper muscle planes and the nodal basin, demonstrate this point. This consumptive process gathers momentum at an alarming speed, hence, the treatment must be aggressive and prompt.

Extramammary Paget's disease (EMPD) is a rare entity, especially in the perinoscrotal region, and typically presents in elderly white patients as a pruritic white or red patch in the area of distribution of apocrine glands. Typically, it affects a single site. Since its manifestations are insidious and easily misdiagnosed, the appropriate manage-ment is delayed. Management of this problem is complex and effective treatment can not only lower recurrence rates but also pro-vide an optimal reconstructive result.The present report describes three patients with scrotal EMPD. Based on literature search, the etiopathology, diagnosis and management of these lesions is discussed. Reconstructive options, with special emphasis on scrotal lesions, are also discussed.

Adult human bone marrow (ABM) is an important source of hematopoietic stem cells for transplantation in the treatment of malignant and nonmalignant diseases. However, in contrast to the recent progress that has been achieved with umbilical cord blood, methods to expand ABM stem cells for therapeutic applications have been disappointing. In this study, we describe a novel culture method that uses human brain endothelial cells (HUBECs) and that supports the quantitative expansion of the most primitive measurable cell within the adult bone marrow compartment, the nonobese diabetic/severe combined immunodeficient (NOD/SCID) repopulating cell (SRC). Coculture of human ABM CD34+cells with brain endothelial cells for 7 days supported a 5.4-fold increase in CD34+cells, induced more than 95% of the CD34+CD38−subset to enter cell division, and produced progeny that engrafted NOD/SCID mice at significantly higher rates than fresh ABM CD34+cells. Using a limiting dilution analysis, we found the frequency of SRCs within fresh ABM CD34+cells to be 1 in 9.9 × 105cells. Following HUBEC culture, the estimated frequency of SRCs increased to 1 in 2.4 × 105cells. All mice that received transplants of HUBEC-cultured cells showed B-lymphoid and myeloid differentiation, indicating that a primitive hematopoietic cell was preserved during culture. Noncontact HUBEC cultures also maintained SRCs at a level comparable to contact HUBEC cultures, suggesting that cell-to-cell contact was not required. These data demonstrate that human brain endothelial cells possess a unique hematopoietic activity that increases the repopulating capacity of adult human bone marrow.

Adult human bone marrow (ABM) is an important source of hematopoietic stem cells for transplantation in the treatment of malignant and nonmalignant diseases. However, in contrast to the recent progress that has been achieved with umbilical cord blood, methods to expand ABM stem cells for therapeutic applications have been disappointing. In this study, we describe a novel culture method that uses human brain endothelial cells (HUBECs) and that supports the quantitative expansion of the most primitive measurable cell within the adult bone marrow compartment, the nonobese diabetic/severe combined immunodeficient (NOD/SCID) repopulating cell (SRC). Coculture of human ABM CD34+ cells with brain endothelial cells for 7 days supported a 5.4-fold increase in CD34+ cells, induced more than 95% of the CD34+CD38− subset to enter cell division, and produced progeny that engrafted NOD/SCID mice at significantly higher rates than fresh ABM CD34+ cells. Using a limiting dilution analysis, we found the frequency of SRCs within fresh ABM CD34+ cells to be 1 in 9.9 × 105 cells. Following HUBEC culture, the estimated frequency of SRCs increased to 1 in 2.4 × 105cells. All mice that received transplants of HUBEC-cultured cells showed B-lymphoid and myeloid differentiation, indicating that a primitive hematopoietic cell was preserved during culture. Noncontact HUBEC cultures also maintained SRCs at a level comparable to contact HUBEC cultures, suggesting that cell-to-cell contact was not required. These data demonstrate that human brain endothelial cells possess a unique hematopoietic activity that increases the repopulating capacity of adult human bone marrow.

Retroviral gene transfer studies targeting bone marrow CD34+CD38- stem cells have been disappointing because of the rarity of these cells, their G0 cell cycle status, and their low or absent expression of surface retroviral receptors. In this study, we examined whether preincubation of bone marrow CD34+CD38- stem cells with a hematopoietically supportive porcine microvascular endothelial cell line (PMVECs) could impact the cell cycle status and expression of retroviral receptors in pluripotent CD34+CD38- cells and the efficiency of gene transfer into these primitive target cells. PMVEC coculture supplemented with GM-CSF + IL-3 + IL-6 + SCF + Flt-3 ligand induced >93% of the CD34+CD38- population to enter the G1 or G2/S/M phase while increasing this population from 1.4% on day 0 to 6.5% of the total population by day 5. Liquid cultures supplemented with the identical cytokines induced 73% of the CD34+CD38- population into cell cycle but did not maintain cells with the CD34+CD38- phenotype over time. We found no significant increase in the levels of AmphoR or GaLVR mRNA in PMVEC-expanded CD34+CD38- cells after coculture. Despite this, the efficiency of gene transfer using either amphotropic vector (PA317) or GaLV vector (PG13) was significantly greater in PMVEC-expanded CD34+CD38- cells (11.4 ± 5.6 and 10.9 ± 5.2%, respectively) than in either steady state bone marrow CD34+CD38- cells (0.6 ± 1.7 and 0.2 ± 0.6%, respectively; p < 0.01 and p < 0.01) or liquid culture-expanded CD34+CD38- cells (1.4 ± 3.5 and 0.0%, respectively; p < 0.01 and p < 0.01). Since PMVEC coculture induces a high level of cell cycling in human bone marrow CD34+CD38- cells and expands hematopoietic cells capable of in vivo repopulation, this system offers potential advantages for application in clinical gene therapy protocols.

Researchers have recently suggested that rigid fixation of the immature bony skeleton may restrict growth and development. This study assesses the effect on postnatal growth of an in utero tibial osteotomy fixed with a miniplate in fetal sheep. A midshaft osteotomy was performed on fetal sheep tibia (n5) at 95 days' gestation (term 145 days). One tibia was reduced and fixed with a titanium miniplate and screws, while the contralateral hindlimb served as a control. The newborns were vaginally delivered and sacrificed at 2 months of age. The hindlimbs, control and fractured, were harvested, stripped of soft tissue, and the tibia, femur, and distal metatarsal were each measured and weighed. Each tibia also underwent radiographic analysis and histologic examination (after decalcification) using hematoxylin and eosin, Sirius red, and Alcian blue stains.

Although clinical and experimental findings have demonstrated that fetal softtissue wounds heal without scarring, very little is known about the process of fetal bone healing. This study examined fetal long bone healing in utero, both histologically and biochemically, with and without fracture fixation in a fetal sheep model. Our study group consisted of 25 live fetuses from 16 ewes. There were 50 fetal tibias in this group 12 were control, 17 were fixed miniplate fixation, and 21 were nonfixed. A midshaft osteotomy of the tibia, either fixed or nonfixed, was performed on fetal sheep at 95 days' gestation term 145 days in utero. The sheep were then killed at one of five postoperative time intervals weeks 1, 2, 3, 4, and 7, and fetal bone healing was examined. The variables reviewed included gross morphology, histology, radiology, and collagen analysis proportions of types II to I and III to I collagen. Fetal bone healing without fixation was accompanied by a large callus with rapid and abundant cartilage and collagen deposition. Bone healing was characterized by malunion or nonunion at 7 weeks. However, with miniplate and screw fixation, callus formation was minimal primary bone healing occurred by 3 weeks and did not adversely affect long bone growth. Analysis of callus samples revealed a minimal amount of type III collagen, whereas the proportion of type II collagen was variable and proportional to the content of callus cartilage. Plast. Reconstr. Surg. 92 874, 1993.

A number of reconstructive options are possible for the patient afflicted with an intraoral malignancy. The reconstructive technique used depends on the stage of the disease and the extent of the soft- and hard-tissue defects formed following extirpation. If local tissues are not available for reconstruction, the surgeon must look to more distant sites in choosing a reconstructive procedure. Microsurgical transfer of composite tissues has allowed surgeons a high degree of success in effecting immediate one- stage closure of complex three-dimensional wounds.

Midfacial and orbital defects formed following ablative oncologic surgery are difficult problems for the reconstructive surgeon, whose goals are to address the devastating functional and aesthetic consequences of these extirpations and to improve the quality of life for this group of patients. This article discusses the various defects and the best methods of treatment and reconstruction for each.

This is the first series of total penile reconstructions with the free sensate osteocutaneous fibula flap. The main advantages of this flap lie in its intrinsic rigidity, its superior donorsite location, and its long vascular pedicle. The fibula flap provides better bone volume than does the radial forearm flap, which commonly results in a floppy phallus in the absence of bone. Penile prostheses in other flaps have enjoyed limited success. Forearm donorsite complications can be avoided. The donor site in the lower extremity can be readily covered with a sock. The vascular pedicle of the fibula flap is of sufficient length to allow endtoside anastomosis of the flap to the femoral artery. Interpositional vein grafts are unnecessary, and dissection of the inferior epigastric artery system to serve as a donor artery may be avoided. The appearance of the neophallus is excellent. We present only the first four continuous cases of the six we have performed because sufficient followup data are available only for these four. The advantages and disadvantages of fibula and forearm donor sites, the longterm fate of the bony component, the importance of sensation, and the vascularized urethral reconstruction are discussed. High patient satisfaction and the advantages of the technique convince us that the fibula osteocutaneous flap is superior for total penile reconstruction. Plast. Reconstr. Surg.92 1314, 1993.

Stigmatic exudate-eating chironomid flies (Smittia) and pollen-eating halodid beetles are the most common visitors to flowers ofPseudowintera colorata. Plants are self-incompatible. After selfing pollen tubes penetrate the nucellus; chase pollination experiments show that the incompatibility reaction occurs before fertilization. When pollen is applied to stigmas, the exudate dries rapidly and does not usually reappear. A review of anthophytes suggests that their common ancestor around 200 mya was bisexual and pollinated at least in part by nectar-seeking insects, possibly including flies. The angiosperm stigma appears to have evolved from a pollination drop mechanism via an adaxial stigmatic surface.

Tetrabutylammonium salts of the mixed haloindates, [Bu4N][InCl3X], X=Cl, Br, I, interact with aromatic solvents forming liquid inclusion compounds. The aromatic/cation ratio (A/C), a measure of the amount of guest aromatic, has been determined for a variety of simple aromatics. The values range from 2.6 to 0.4, substantially lower than the A/A of similar [Bu4N][Al2R6X] liquid clathrates. The ability of these liquid clathrates to function as catalysis media has been explored. The solubility of (Ph3P)2Rh(CO)Cl and (Ph3P)3RhCl in the various clathrates was determined. It was found that significant leaching of the catalyst into the bulk aromatic solvent occurred, ranging from 13 to 94%. A related liquid clathrate, [Li·12-crown-4][InCl4]·(C6H5CH3)2, had <1% of the dissolved catalyst leached.

Abstract: Background: We sought to determine the competence of medical students and surgery residents in evaluating clinical problems (using both real and simulated patients) in surgical oncology. Methods: Forty-five third-year medical students, 23 first postgraduate year (PGY-1) residents, and seven second postgraduate year (PGY-2) residents were presented with the same four clinical problems (breast evaluation, prostate nodule, colon cancer, and mole evaluation). The two resident groups were presented with two additional patients (breast cancer options and thyroid mass). Results: Mean performance scores for the problems were generally poor (32–72%); most students and residents failed almost all of the problems. Level of training was of some importance; the overall mean scores of the PGY-2 residents were superior to those of the medical students and the PGY-1 residents (p=0.049). However, in many areas of information gathering, diagnosis, and management, training level appeared to have no impact. Numerous important performance deficits were identified in all groups. Conclusion: Medical students and surgery residents are not receiving adequate training in diagnosing and treating important problems in surgical oncology.

We have developed a lyophilized bone morphogenetic protein (BMP) delivery device that can be formulated to control release over 2 to 8 weeks. Bioerodible poly (d,1 lactide-co-glycolide) particles loaded with 90 μg recombinant human BMP-2 were suspended in either carboxymethylcellulose (CMC) or methylcellulose (MC) implants. Plain CMC and MC implants served as controls, as did a nonim-planted group. A total of 40 rabbits was evaluated histologically 2, 4, or 8 weeks after receiving circular full-thickness 15-mm calvarial defects. MC appeared to prevent prolapse of periosteum and dura into the defects and did not elicit bone growth. Addition of BMP improved the result. CMC implants appeared to encourage bone growth even in the absence of BMP. When BMP was added, new bone formed earlier. CMC may influence new bone formation because it is hydrophilic. MC is less hydrophilic and may cause undue inflammation. Either can be combined with BMP to produce unitary devices that are easy to make and use.

The AMAC IIIS electrooptical transducer for flow cytometry facilitates simultaneous measurements of electrical impedance and several optical properties of single cells. Ray-trace analysis demonstrates that its spherical exterior permits light rays to emerge effectively undeviated and thus lowers the required numerical aperture of the collecting lens as compared with a flat surfaced transducer. This feature results in an increased light-gathering ability, an increased depth of focus, minimum spherical and chromatic aberrations, and minimizes the optical volume observed.

Patients with facial palsy present with a multitude of different problems to which individual solutions must be carefully tailored. Although numerous surgical options exist, the results of reconstruction are rarely ideal. This article discusses different surgical procedures for reconstruction of the eye and mouth with special emphasis on the newer technique of microsurgical transfer of muscle tissue for reanimation.

A new technique is described for stabilizing complex vertical fractures of the maxilla. Advantageous use of the comminuted fracture pattern of the maxillary buttresses allows the maxilla to be divided into two parts at the Le Fort I level. with intermaxillary fixation applied, stabilization is achieved by applying miniplate fixation to the nasal side of the hard palate. The maxilla is reduced to the previously stabilized anterior midfacial buttresses with plates and screws. Comminuted segments of defects in the anterior buttresses are replaced with contoured calvarial grafts. This method has the advantage of maintaining transverse palatal width in a rigid fashion without the need for further osteotomies. It has satisfactorily restored preinjury occlusal relationships in six patients, without the need for dental splints. In no instance has hardware extrusion occurred after fixation.

This paper reports on the incorporation of personal computers in the laboratory program at UMIST's Control Systems Centre. Laboratory practice is an integral component of all our control course. The laboratory facilities provide a mechanism for testing and verifying theoretical and design approaches. Incorporating computers in all phases of the laboratory program makes possible the use of current techniques in the analysis and design of realistic control systems. The control systems laboratory at UMIST has been developed with the goal of providing real world analysis and design experience in a laboratory setting. A collection of scale model experiments representing the major categories of industrial control problems has been constructed. These working models are coupled with a standard instrumentation interface and analogue and digital computers to implement control strategies. In all cases, great care has been taken to retain realism and allow the student to concentrate on control issues rather than configuration or programming problems. The primary objective of using personal computers in the control laboratory is to provide an on-line link between the student and the laboratory model. This provides direct 'hands on' experience of digital control ideas, interactive digital control experimentation and use of the computer as a multi-function virtual instrument. In addition, the computer is used off-line to simulate model performance as various control strategies are tried. At this point in time, each laboratory model station has been equipped with a personal computer containing A/D and D/A converters, hard and floppy disk, and a real-time clock. The computers are networked to provide access to printing and file storage facilities. Originally the software packages were written primarily in BASIC, and ran on BBC computers. These versions are however in the process of being replaced by PC-based packages written in C. Both the original BASIC and the C-successors have been developed to provide interactive, real-time control of the model using a choice of digital control algorithms. Using the keyboard as a control panel, the student can observe model performance, vary controller parameters, choose display characteristics and record parametric and graphical data. Future developments will expand the choice of available control algorithms and enhance the off-line analysis and design tools.