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Barrier removal is a recognized solution for reversing river fragmentation, but restoring connectivity can have consequences for both desirable and undesirable species, resulting in a connectivity conundrum. Selectively passing desirable taxa while restricting the dispersal of undesirable taxa (selective connectivity) would solve many aspects of the connectivity conundrum. Selective connectivity is a technical challenge of sorting an assortment of things. Multiattribute sorting systems exist in other fields, although none have yet been devised for freely moving organisms within a river. We describe an approach to selective fish passage that integrates ecology and biology with engineering designs modeled after material recycling processes that mirror the stages of fish passage: approach, entry, passage, and fate. A key feature of this concept is the integration of multiple sorting processes each targeting a specific attribute. Leveraging concepts from other sectors to improve river ecosystem function may yield fast, reliable solutions to the connectivity conundrum.

Wartime America underwent rapid transformation; men, women, and children saw their social roles redefined; and economic and racial divisions grew deeper and sharper edged. Theater was the perfect medium to represent home-front tensions and anxieties as they were manifested on the local level: the congenital civilian thrust into the military life as in Strip for Action and This Is the Army; the family pressured by rapid and dynamic social transformations as in Three's a Family, A New Life, and Men to the Sea; couples pressured by the carpe-diem spirit of the wartime romance as in On the Town and Those Endearing Young Charms; adolescents, often tempted into juvenile delinquency with the freedom of looser rules and mores as in Janie and Pick-Up Girl; men and women balancing patriotism and selfishness, as in The Voice of the Turtle and the shocking Tomorrow the World.

A better understanding of how human activities affect biodiversity can be important for effective resource management. We tested how excavation (maintenance) of agricultural drains (ditches) altered fish assemblages. Uncertainty regarding the effects of drain maintenance on fish assemblages has been a source of tension between landowners, drain superintendents, and fishery managers. Fish assemblages in eight southwestern Ontario drains were sampled repeatedly from before to 2 years after drain maintenance using a replicated before–after, control–impact (BACI) design. Relative to reference sites, we found no evidence for short- or long-term decreases in the number of species and total abundance of fishes following drain maintenance, nor any consistent change in assemblage composition, despite clear changes in physical habitat. The fish assemblages in drains were resilient to drain maintenance and did not show changes expected to concern fishery managers. Our findings provide fishery managers with the information needed to manage drain maintenance more effectively under the Fish Protection Program of the Fisheries Act and to develop drain maintenance practices that balance the needs of agriculture with the protection of fish biodiversity.

Partial migration is a widespread phenomenon characterized by migrant and resident forms from the same population. In phenotypically plastic taxa with indeterminate growth, resident and migrant ecophenotypes can differ in size and life history traits in ways expected to maximize fitness in the different habitats they exploit. Studies of partial migration in different taxa have advocated either density-dependence or environmental stochasticity as explanations for partial migration. We used a demographic approach for a virtual Brook Trout population to demonstrate the ecological consequences of partial migration under interacting density dependence and environmental stochasticity. The maintenance of partial migration as a conditional strategy in species/populations where resident and migrant forms exhibit life history asymmetries provides ecological advantages. We show that density-dependent migration is expected to increase population fitness under constant environmental conditions or low environmental variation, but decreases population fitness under high environmental variation. These conditions favor intermediate levels of migration as an advantageous tactic. However, there are threshold rates of return migration below which partial migration is no longer a viable tactic. Our modeling approach also allowed the exploration of the distribution of the population by life stage and habitat in response to the strength of density dependence, costs of migration, and return rates, and demonstrated the importance of the conservation of ecophenotypes in partially migratory populations.

Open agricultural drains (ditches) provide necessary drainage for cropland and may also provide habitat supporting native fish assemblages. We tested whether warm-water drains in southwestern Ontario provide fish habitat similar to that of reference watercourses not subjected to drain maintenance. Features of fish assemblages and habitats were characterized using standardized protocols in 24 pairs of drains and reference watercourses. Drains and reference watercourses did not differ significantly in fish species richness, evenness, abundance, biomass, species composition, life stages, or nine of 13 physical habitat attributes expected to be altered by drain maintenance. These findings do not support concerns that drain maintenance has strong, lasting effects on fish assemblages and physical habitat features. Other landscape-level agricultural impacts may affect both drains and reference watercourses but were not examined in this study. We recommend that drains continue to be recognized as fish habitat under the Canadian Fisheries Act and that drain and fish habitat managers strive for logical, scientifically defensible drain maintenance practices that preserve fish biodiversity and habitat, while considering the needs of agriculture.

This chapter places the musical theater of Stephen Sondheim and his collaborators in two contexts: the late-1960s aesthetic exhaustion of the integrated musical play and the rise of postmodernism as a cultural dominant. Self-referentially unintegrated and self-consciously performative, Sondheim’s musicals move beyond the constraints of the musical play and participate in the postmodern critique of narrative as an aesthetic, epistemological, and ontological structure.Company(1970) andFollies(1971) use a formal critique of narrative to disconnect identity from the structure of the life story.Merrily We Roll Along(1981) employs a backward-moving narrative to problematize a structure-completing, progressive conception of time.Road Show(2008) replaces the exhausted master narrative of the American Dream with multiple temporary and contingent narratives.

Noninvasive tests for the evaluation of chronic venous insufficiency (CVI) include quantitative photoplethysmography (QPG), air plethysmography, and duplex ultrasonography measurement of valve closure time (VCT). These tests have been shown to accurately identify the presence of CVI, define the disease, and locate the involved segments. However, the correlation of noninvasive assessment of CVI with the clinical severity (Society for Vascular Surgery/International Society for Cardiovascular Surgery staging) has not been addressed critically.During an 18-month period, 74 limbs were prospectively evaluated with clinical examination, air plethysmography, QPG and duplex ultrasonography.We studied 52 patients with a mean age of 46 years. There were 14 stage 0 limbs, 14 stage 1, 15 stage 2, and 31 stage 3. We found significant differences (p0.05) between normal limbs and those with CVI only by VCT and QPG. There were also marked trends toward worsening mean values for reflux (VCT, QPG, and venous filling index) and venous hypertension (residual volume fraction) between stages 0 to 1, and 1 to 2; however, there was a large degree of overlap between all groups. No test discriminated stage 2 from 3. Assessment of calf muscle pump function with ejection fraction showed no difference between any groups.The Society for Vascular Surgery/International Society for Cardiovascular Surgery criteria for CVI staging distinguishes ulcerated limbs (stage 3) from those with nonulcerating skin changes (hyperpigmentation, brawny edema, and subcutaneous fibrosis) (stage 2). However, we were not able to distinguish these groups by available noninvasive methods. This may imply that these tests are not accurate enough or that the progression from lipodermatosclerosis to frank ulceration is not accounted for by large-vessel hemodynamic changes, but rather by microcirculatory alterations.

Serial monitoring of vein graft peak systolic flow velocity (PSFV) has been endorsed as a technique for vein graft surveillance with low values (45 cm/sec) considered a marker for impending graft failure. Optimal application of this method requires an understanding of the factors affecting PSFV in normal grafts. A prospective evaluation of 46 consecutive elective infrainguinal vein grafts (6 popliteal/29 tibial/11 pedal) was undertaken to assess the major determinants of PSFV.Factors recorded for each patient included vein graft diameter (VGD), measured outflow resistance (MOR), conduit length, outflow level (popliteal/tibial/pedal), inflow level (femoral/popliteal), systolic blood pressure, cardiac ejection fraction, the presence of a patent plantar arch, and Society for Vascular Surgery/International Society for Cardiovascular Surgery resistance scoring. MOR was measured by occluding graft inflow and infusing saline solution through a proximal graft cannula at 60 cc/min while simultaneously recording the pressure at the distal anastomosis via a separate cannula. MOR was calculated by dividing the resultant pressure by the infusion rate. MORs were expressed in resistance units and were measured before and after the infusion of papaverine (MOR(PAP). PSFVs and VGDs were measured 4 to 6 cm from the distal anastomosis 3 weeks after surgery with duplex scanning (60 degree angle with midstream sample volume).PSFVs ranged from 22 to 148 cm/sec and averaged 83.4 +/- 4.8 cm/sec. Pedal bypass grafts had significantly lower PSFVs (64 +/- 10 vs 89.5 +/- 5 cm/sec, p = 0.02) and significantly higher MOR(PAP)s (0.86 +/- 0.15 vs 0.51 +/- 0.05 resistance units, p = 0.05) than bypasses to the popliteal/tibial level. When subjected to univariate analysis the factors correlating with PSFV were MOR (r = -0.59, p = 0.0001), MOR(PAP) (r = -0.69, p = 0.0001) VGD (r = -0.31, p = 0.06), the Society for Vascular Surgery/International Society for Cardiovascular Surgery score (r = -0.35, p = 0.04), inflow level (r = -0.47, p = 0.002), and outflow level (r = -0.35, p = 0.03). When subjected to multiple regression analysis, only MOR(PAP) (r2 = 0.51, p = 0.001) and VGD (r2 = 0.14, p = 0.001) contributed significantly to the overall model (r2 = 0.65, p = 0.0001) with MOR(PAP)) eliminating the effect of the other variables. The multiple regression model predicts PSFV as follows: PSFV = 176 + VGD(mm) (-11.7) + MOR(PAP)) (-63.4).Clinically successful and hemodynamically normal vein grafts have widely variable, yet predictable flow characteristics that are influenced primarily by outflow resistance and VGD. This wide variability suggests that no single lower threshold value for PSFV is universally applicable indentifying all grafts at risk for failure. Detection of focal areas of flow acceleration within the graft may be more accurate in identifying grafts at risk for failure.

Although Thomas Pynchon has famously avoided the spotlight, he and his work—especially Gravity’s Rainbow —nevertheless cast a large shadow over contemporary American fiction. In a Bloomian anxiety of influence, a subsequent generation of fiction writers—I’m thinking of writers like the late David Foster Wallace, William T. Vollmann, Rick Moody, Bradford Morrow, Mary Caponegro, Michael Chabon, A. M. Homes, Colson Whitehead, and the subject of the collection of essays under review, Richard Powers—has been inspired to write by Pynchon’s great novels but has also sought to find a way out from under their shadow. This anxiety is made more acute by the concomitant sense that the postmodernism exemplified by Pynchon and his fellow experimental writers of the sixties and seventies (Barth, Coover, Sorrentino, Gaddis, Barthelme, Reed, and so on) has reached something of a dead end. That is, postmodernism’s consciousness of language, its iconoclasm, and its questioning of all master narratives, which in the 1960s played an important role in exposing and debunking many long-held social conceits and hypocrisies, by the late 1980s and 1990s had devolved into an all-purpose irony, the rolling of the eye and the nudging in the ribs that mocks any assertion that eschews irony’s game and aspires to sincerity. As Wallace explained in a 1993 interview with Larry McCaffery, “Irony’s useful for debunking illusions, but most of the illusion-debunking in the U.S. has now been done and redone. . . . All we seem to want to do is keep ridiculing the stuff. Postmodern irony and cynicism’s become an end in itself, a measure of hip sophistication and literary savvy. . . . Irony’s gone from liberating to enslaving” (147).

To assess the role of noninvasive tests--quantitative photoplethysmography, air plethysmography, and quantitative duplex scanning, we compared a group of normal (group N, eight limbs) volunteers to patients with severe chronic venous insufficiency who were stratified according to the degree of reflux seen on the current "gold standard," descending phlebography. Group M (10 limbs) had mild (grades 0 to 2) reflux, and group S (10 limbs) had severe (grades 3 to 4) reflux as determined by phlebography. Quantitative photoplethysmography could identify normal from abnormal limbs but could not distinguish the severity of reflux. Air plethysmography was used to calculate venous filling index, ejection fraction, and residual volume fraction. Ejection fraction was the same in all groups. Venous filling index could not significantly distinguish the degree of reflux (group M vs group S) but increased as reflux increased. Residual volume fraction was considerably higher in group S. Quantitative duplex valve closure time was measured in the superficial femoral and popliteal veins, with the values added together in each limb to give a total valve closure time (TVCT). A TVCT value greater than or equal to 4 seconds correlated best with severe phlebographic reflux, with a sensitivity of 90%, a specificity of 94%, and an accuracy of 93%. This value was confirmed as the best test for venous reflux by receiver operating characteristic curve analysis. Thus in the evaluation of patients with severe chronic venous insufficiency who are candidates for phlebography and surgery, quantitative duplex measurement of TVCT gives the best noninvasive assessment of the severity of deep venous reflux.

Femoral vein valvuloplasty (FVV) is the operation of choice for primary valvular incompetence, but this procedure is highly operator dependent for judging the competence of the valve repair during surgery. We have reviewed our experience with FVV, focusing on the utility of angioscopic-guided valve repair and hemodynamic results. Nine limbs in six patients underwent superficial FVV. There were four men and two women; the average age was 49 years (range 32 to 62 years). All limbs were Society for Vascular Surgery/International Society for Cardiovascular Surgery clinical stage III (venous ulcer), and descending phlebography showed grade 4 reflux in six limbs, grade 3 reflux in one limb, and grade 2 reflux in two limbs. In addition to FVV, five limbs underwent subfascial ligation of incompetent perforators and three limbs underwent ligation and stripping of superficial varicosities. Two limbs underwent polytetrafluoroethylene wrapping of the valvuloplasty. The last five valvuloplasties underwent angioscopic evaluation of the repair, and the last two procedures were closed valvuloplasties (without venotomy). Follow-up averaged 20.3 months (range 2 to 51 months). In all patients ulcers healed without recurrence. There were two perioperative deep vein thromboses in the polytetrafluoroethylene wrapped repairs. All superficial femoral veins were patent by duplex scanning at the time of follow-up. Venous refill time measured by light reflection rheography did not improve after surgery. Venous filling index measured by air plethysmography showed near normalization (3.83 +/- 0.82) after angioscopically guided FVV.(ABSTRACT TRUNCATED AT 250 WORDS)

Duplex scanning has recently been used to monitor the patency of infrainguinal vein grafts. Empirically derived criteria that have been used for identifying the failing graft have never accounted for the effect of vein graft diameter or varying outflow resistance, despite the fact that they are major determinants of flow. We prospectively examined the variation in graft peak systolic flow velocity with graft diameter and outflow level in a consecutive series of 68 patients with 72 normally functioning vein grafts returning for routine follow-up. Images were obtained of vein grafts with a duplex scanner throughout their lengths, and the distal peak systolic flow velocity and intraluminal diameters were recorded. There were 15 popliteal, 26 tibial, and 21 inframalleolar grafts. The mean ankle-brachial index of inframalleolar grafts was 1.01 ± 0.04 and did not differ significantly from tibial (0.96 ± 0.03) or popliteal (0.93 ± 0.06) grafts ( p = 0.32). Grafts to the three outflow levels differed significantly in diameter, with inframalleolar grafts measuring 3.95 ± 0.17 mm, tibial grafts 4.78 ± 0.21 mm, and popliteal grafts 5.65 ± 0.38 mm ( p = 0.0001). In a similar manner inframalleolar grafts had significantly lower peak systolic flow velocities (59.1 ± 3.4 cm/sec) than tibial (77.2 ± 5.6 cm/sec) or popliteal (71.0 ± 7.6 cm/sec) grafts ( p = 0.04). Inframalleolar grafts did not demonstrate a significant correlation ( r = −0.21, p = 0.29) between peak systolic flow velocity and graft diameter. Conversely, both tibial ( r = −0.49, p = 0.005) and popliteal ( r = −0.73, p = 0.002) grafts demonstrated significant inverse correlations. Furthermore, linear regression analysis revealed that popliteal and tibial grafts shared a similar and predictable inverse relationship between peak systolic flow velocity and graft diameter. We propose that consideration of peak systolic flow velocity independent of graft diameter is a suboptimal indicator of impending graft failure. Comparison of each peak systolic flow velocity with a diameter-specific range of acceptable values should improve the accuracy of duplex scan surveillance studies. (J Vasc Surg 1992;15:991–9.)

The colonial situation–that is, the relation, especially the power dynamics, between the colonizer and the colonized–plays an important part in much of Pynchon's writing. In the early short story "Mortality and Mercy in Vienna," an Ojibwa Indian, brought like a prize of conquest to Washington, DC, erupts into a traditional homicidal psychosis of his tribe, exposing as empty and powerless the capital-crowd cocktail-party conversation which seeks to define and control him. In V., Foppl's siege party seeks to conjure up the ecstasy of power associated with von Trotha's 1904 genocidal campaign against the Hereros; and British explorer Hugh Godolphin, like Conrad's Marlow, recognizes the connection between the process of mapping and naming unknown spaces and the imperial desire to know and thus control the world. "A Journey into the Mind of Watts" and Vineland both suggest that potentially dissident sections of the United States are metaphorical third-world countries and are brought under control through imperial processes. And, of course, Mason & Dixon focuses on the ways institutionalized ideologies, epistemologies and discourses seek to possess a continent and control its people.

Gravity's Rainbow complicates traditional notions of narrative and self in two interconnecting ways. The text is both a narrative that problematizes the individuated self and a metafiction that problematizes the forms traditionally seen as making narrative a vehicle for communicating meaning. From Pirate Prentice's managing other people's fantasies to Siothrop's disappearance, the text challenges the idea of a coherent, self-responsible individual interacting uniquely with the world. As a metafiction, the text challenges the cause-and-effect assumptions behind narrative sequence and the hermeneutical assumptions behind evaluation and interpretation of narrative discourse. These two challenges are manifested in the narrative of Franz Pokler. The dominant consciousness in the longest chapter in Gravity's Rainbow, Pokier tries to assess his situation by looking back at his years as a scientist in the V-2 rocket program, essentially trying to organize his life story.

Most of the songs in Gravity's Rainbow appear to be based, some closely, some loosely, on already existing songs to which Pynchon has written new lyrics. Appropriate to the nexus of film allusions and images in the text, some of Pynchon's songs are based on music written for the movies. I have identified specific sources for two songs that have not previously been accounted for. Together, the two allusions illustrate the contradictory ways the narrator of Gravity's Rainbow uses film references.

The best way to quantitate venous reflux is still a matter of debate. Duplex-derived valve closure time (VCTs) have been used recently because they can be measured easily. We examined the relationships between VCT and duplex-obtained quantitation of venous volume and between VCT and air plethysmography (APG). Sixty-nine legs in 45 patients with varying clinical degrees of chronic venous insufficiency were studied by duplex scan and APG. VCTs were compared with duplex-derived flow calculations and with APG-derived venous filling index and residual volume fraction. The patient's mean age was 47.5 +/- 13.9 years; the mean duration of their symptoms was 13 +/- 4 years. Twenty percent had a history of deep venous thrombosis, and 29% had undergone venous surgery. No correlation was found between VCT and flow volume or between VCT and flow at peak reflux at any of the anatomic locations studied: saphenofemoral junction, greater saphenous vein, lesser saphenous vein, superficial femoral vein, profunda femoris vein, and popliteal vein. Likewise, no correlation was found between total VCT and APG-derived venous filling index or between total flow volumes and APG-derived residual volume fraction. Total VCT and total flow volumes did, however, have a moderate correlation (r = 0.65; p = 0.0003). Duplex-derived VCTs, although extremely useful in determining the presence of reflux, do not correlate with the magnitude of reflux, and should not be used to quantitate the degree of reflux.

Pinpointing the origins of ideas in a writer's work is an often difficult task with not always relevant results. Nevertheless, much excellent scholarship has been devoted to discovering and explicating possible sources for motifs and episodes in Pynchon's work. Pynchon himself, in both his fiction and the few published remarks he has made about his own work, has indicated some of the most important influences on him, some serious, others pop cultural. In the introduction to Slow Learner, for example, Pynchon admits he "had grown up reading a lot of spy fiction, novels of intrigue." And in apologizing for the "racist, sexist, and proto-Fascist talk" in "Lowlands," he explains, "The best I can say for it now is that, for its time, it is probably authentic enough. John Kennedy's role model James Bond was about to make his name by kicking third-world people around, another extension of the boy's adventure tales a lot of us grew up reading" (11). Pynchon's familiarity with Ian Fleming's James Bond novels may account for how a specific idea in one of them, Moonraker, found its way also into Gravity's Rainbow.

One of the ways Gravity's Rainbow refuses to cooperate in its own interpretation is by refusing to let the reader be confident about what he or she can "know" is "true" in the novel. That is, the reader is repeatedly confused about which events are supposed to be actually occurring in the world of the novel and which are not. The novel combines carefully researched facts about the rocket program, the V-2 blitz of London, and postwar Germany with pynchon's own fictional creations. In addition, the narrator swings wildly from being grittily realistic and intensely serious to being outrageously fantastic and sarcastically parodic. Pynchon often makes it impossible for us to judge the significance of those parts of the novel that fall between these extremes. Yet the amount of seriousness we grant these parts can affect our interpretation of the work as a whole. Among the novel's ambiguities are the mysterious, giant, supernatural beings who appear from time to time to observe the action. These beings, especially the Angel of Ldbeck, have usually been identified as Rilkean Angels. However, a study of the way these beings function in the novel and of other uses of "angel" imagery suggests instead that they are the ultimate manifestation of Them, the novel's ubiquitous controllers. This interpretation implies that the supernatural Other side is not a holistically unified realm free of the divisions and distinctions made and enforced by earthly controllers, as some of the characters claim, but rather the originary system of control that structures the entire life/death system.