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Bax inhibitor 1 (BI-1) was originally discovered as an inhibitor of Bax-induced apoptosis; this review highlights the fundamental importance of BI-1 in a wider context, including in tissue homeostasis and as a regulator of cellular stress. BI-1 has been shown to interact with a broad range of partners to inhibit many facets of apoptosis, such as reactive oxygen species production, cytosolic acidification and calcium levels as well as endoplasmic reticulum stress signalling pathways. BI-1's anti-apoptotic action initially enables the cell to adapt to stress, although if the stress is prolonged or severe the actions of BI-1 may promote apoptosis. This almost universal anti-apoptotic capacity has been shown to be manipulated during infection with enteropathogenic and enterohaemorrhagic Escherichia coli inhibiting host cell death through direct interaction between their effector NleH and BI-1. In addition, BI-1 activity is important in a large number of cancers, promoting metastasis by modulating actin dynamics, a process dependent upon the BI-1 C-terminus and BI-1:actin interaction. Manipulation of BI-1 therefore has the potential for significant therapeutic benefit in a wide range of human diseases.

When ultrasonography is used to investigate deep-vein thrombosis, serial testing is recommended for those who test negative initially. Serial testing is inconvenient for patients and costly. We aimed to assess whether the calculation of pretest probability of deep-vein thrombosis, with a simple clinical model, could be used to improve the management of patients who present with suspected deep-vein thrombosis. Consecutive outpatients with suspected deep-vein thrombosis had their pretest probability calculated with a clinical model. They then underwent compression ultrasound imaging of proximal veins of the legs. Patients at low pretest probability underwent a single ultrasound test. A negative ultrasound excluded the diagnosis of deep-vein thrombosis whereas a positive ultrasound was confirmed by venography. Patients at moderate pretest probability with a positive ultrasound were treated for deep-vein thrombosis whereas patients with an initial negative ultrasound underwent a single follow-up ultrasound 1 week later. Patients at high pretest probability with a positive ultrasound were treated whereas those with negative ultrasound underwent venography. All patients were followed up for 3 months for thromboembolic complications. 95 (16 ·'0%) of all 593 patients had deep-vein thrombosis; 3%, 17%, and 75% of the patients with low, moderate, and high pretest probability, respectively, had deep-vein thrombosis. Ten of 329 patients with low pretest probability had the diagnosis confirmed, nine at initial testing and one at follow-up. 32 of 193 patients with moderate pretest probability had deep-vein thrombosis, three diagnosed by the serial (1 week) test, and two during follow-up. 53 of 71 patients with high pretest probability had deep-vein thrombosis (49 by the initial ultrasound and four by venography). Only three (0 ·6%) of all 501 (95% Cl 0 ·1–1 ·8) patients diagnosed as not having deep-vein thrombosis had events during the 3-month follow-up. Overall only 33 (5 ·6%) of 593 patients required venography and serial testing was limited to 166 (28%) of 593 patients. Management of patients with suspected deep-vein thrombosis based on clinical probability and ultrasound of the proximal deep veins is safe and feasible. Our strategy reduced the need for serial ultrasound testing and reduced the rate of false-negative or false-positive ultrasound studies.

Forest fragmentation, the disruption in the continuity of forest habitat, is hypothesized to be a major cause of population decline for some species of forest birds because fragmentation reduces nesting (reproductive) success. Nest predation and parasitism by cowbirds increased with forest fragmentation in nine midwestern (United States) landscapes that varied from 6 to 95 percent forest cover within a 10-kilometer radius of the study areas. Observed reproductive rates were low enough for some species in the most fragmented landscapes to suggest that their populations are sinks that depend for perpetuation on immigration from reproductive source populations in landscapes with more extensive forest cover. Conservation strategies should consider preservation and restoration of large, unfragmented \"core\" areas in each region

1. We report that interspecific territoriality is a common spacing mechanism among closely related bird species distributed along a primary successional gradient in the meander belt of an Amazonian whitewater river. 2. In the first phase of the research, we mapped the territories of more than 330 bird species in large census plots encompassing the complete successional gradient. We found species pairs in over 20 genera that showed contiguous but non-overlapping territories, such that early stages of the successional gradient were occupied by one member of the pair, and later stages by the other. Other species pairs showed additional types of spatial relationships, including partially overlapping and completely overlapping territories. 3. Using reciprocal heterospecific playback experiments, we tested for the existence of aggressive interactions between the members of species pairs (usually congeners) showing all three types of spatial relationship. Among 12 species pairs showing contiguous, non-overlapping territories, 10 showed evidence of interspecific aggression (approach to the plaback speaker). In eight of these 10 cases, the responses were markedly asymmetric. Target individuals of one species approached the speaker, whereas individuals of the other species remained in place or moved away. The heavier species was consistently the aggressor. 4. In six species pairs showing partial territorial overlap along the successional gradient, only one species displayed statistically significant interspecific aggressiveness, although some individuals in all six pairs approached or avoided the speaker. 5. In species pairs distributed with completely overlapping territories, we found interspecific aggression in only one of five genera tested. 6. We suggest that spatial segregation of congeneric bird species on habitat gradients (presumably including elevational gradients), is commonly underpinned by interspecific territoriality mediated through directed, asymmetrical interspecific aggression. Aggressive asymmetry suggests a despotic model of habitat occupancy, in which the larger species occupies the more productive end of habitat gradients, and the smaller species occupies less productive habitats. 7. The pronounced successional gradients characteristic of Amazonia may explain much of the increased species richness, especially within genera, of Amazonian bird communities.

Historical and biogeographic contexts can play important, yet sometimes overlooked, roles in determining structure of local communities. In particular, few examinations of historical influences on patterns of species richness and relative abundances in tropical communities have been conducted. In part, that gap in our knowledge has been caused by a paucity of data on tropical communities, even for relatively well-studied taxa such as birds. In the Neotropics, only two sites, a 97-ha plot in lowland Peru and a 100-ha plot in French Guiana, have been inventoried on a spatial scale sufficient to estimate population densities for a majority of resident bird species. Results from those studies revealed extremely similar species richness, community biomass, and patterns of relative abundance. A third site in lowland Panama was originally censused in 1968-1969 and has often been compared with many other tropical and temperate sites. Results from Panama suggested an exceptionally different community structure from that observed at the Amazonian sites. Informative comparisons among sites have been hampered, however, by differences in sampling protocols. The Panama site was sampled on a much smaller spatial scale (2 ha) than the two Amazonian sites. To improve comparisons, we censused a 104-ha area (the Limbo plot) encompassing the original 2-ha Panama study area and used several census methods, including those used at the Amazonian sites. As expected, spatial scale had a strong effect on estimates of species richness. We detected 252 species on the Limbo plot, compared with 161 detected on the original 2-ha area. Estimates of total individual birds per 100 ha were similar, but estimates from the original study were based on densities measured for one-third fewer species than we measured on our larger study area. Of the 53 species for which both Panama studies estimated population densities, a significant number of estimates were higher in the original study. Thus, the small spatial scale of the original study apparently led to inflated density estimates. The primary cause of disparities appeared to result from undersampling in the smaller plot of many species with patchy distributions and large territory sizes. Compared with Amazonian communities, the Panama community had far fewer rare species. Although 33% of species in Amazonian sites had densities of ≤1 pair/100 ha, only 17% were equally rare in Panama. Furthermore, eight species in Panama were, by tropical standards, \"superabundant,\" attaining densities as high as 212 breeding individuals/100 ha; the most abundant species in Amazonia barely reached one-third of that number. In total, those eight species accounted for 36% of all individuals at Limbo. The median abundance at Limbo was 7 pairs/100 ha, vs. 2.5 pairs/100 ha in Amazonia. Consequently, the total number of birds on the Limbo study area was nearly twice that found in Amazonia, despite species richness being only three-fourths as great. We conclude, first, that spatial scale has indeed had an important effect on the characterization of the Panama bird community. The intrinsically patchy distributions of most forest-dwelling bird species raise the need for large-scale censuses. Second, the Panama community, compared with the two Amazonian sites, has a fundamentally different organization; it hosts nearly twice as many individual birds and is distinctly less dominated by rarity. Similar patterns of community structure appear to be present within tree and mammal communities as well. Therefore, results from the Amazonian studies cannot be generalized to all lowland Neotropical communities. We attribute differences in community structure primarily to differing biogeographic histories. The lower species richness and the greater number of total birds present in Panama appear to derive, at least in part, from two important factors: an area effect linked to the location of Panama on a narrow isthmus, and the repeated history of disturbance on multiple temporal scales in Panama.

We evaluated the effects of perforation, or the creation of small gaps, within a mature, deciduous forest in southern Illinois (U.S.A.) on abundances of breeding birds. Openings of 0.02-0.4 ha were created by group and single-tree selection logging within a 2000-ha tract of forest. We used point counts to compare abundances of birds in uncut forest with those in similar adjacent forest compartments that were recently cut (1-5 years previously) and less recently cut (10-15 years earlier). Most species of forest birds were not significantly less common in logged tracts. Only Red-eyed Vireos (Vireo olivaceus) and Ovenbirds (Seiurus aurocapillus) were significantly more numerous in uncut forest, but the vireo responded negatively to cuts at sites on ridges only, not in ravines, whereas Ovenbird populations differed substantially among years. Blue Jays (Cyanocitta cristata), important nest predators, were significantly more abundant in cut than uncut forest, but brood parasitic Brown-headed Cowbirds (Molothrus ater) showed no consistent differences. Populations of gap-dependent species such as Hooded Warbler (Wilsonia citrina), Indigo Bunting (Passerina cyanea), Whiteeyed Vireo (Vireo griseus), and Carolina Wren (Thryothorus ludovicianus) were dramatically larger in recently cut forest, with populations of most species reaching a peak 2-3 years after cutting. Between 5 and 10 years after cutting, nearly all gap-dependent species had returned to population levels comparable to those in uncut forest. Species dependent upon larger gaps, such as Yellow-breasted Chat (Icteria virens), Blue-winged Warbler (Vermivora pinus), and Prairie Warbler (Dendroica discolor), were absent. We conclude that the first cutting cycle in selective logging had only a minor effect on the forest bird community composition and created a short-lived availability of habitat for gap species. In the southern Illinois landscape, selective logging appeared to add little to the existing effects of forest fragmentation. Effects of perforation may differ in more continuously forested landscapes, however, and may be influenced by total basal area of timber removed and by the length of the inter-cut interval.

We compared the nesting success of a disturbance-dependent species, the Indigo Bunting (Passerina cyanea), on different kinds of habitat edges in five sites (225 total nests) in southern Illinois from 1989 to 1993. Nest predation rates along agricultural and abrupt, permanent edges (e.g., wildlife openings, camp-grounds) were nearly twice as high as rates along more gradual edges where plant succession was allowed to occur (e.g., treefalls, streamsides, gaps created by selective logging). Levels of brood parasitism by Brown-headed Cowbirds (Molothrus ater) varied significantly among sites and years, but not among edge types. Clutch sizes, however, were significantly smaller at agricultural edges where nest predation rates were also high, which suggests either decreased food availability or a population dominated by younger and/or lower-quality (poor condition) birds. The results of this study illustrate the need to reevaluate management practices (e.g., wildlife openings) that are designed to promote populations of disturbance-dependent wildlife.

We studied the nesting success of an individually marked population of Kentucky Warblers (Oporornis formosus), a species that nests in disturbed and undisturbed forests, in a heterogeneous, managed forest site in the Shawnee National Forest in southern Illinois from 1992 to 1995. We examined the effects of forest stand type (clearcuts of various ages, tree plantations, and older forest) and distance from habitat edges on rates of nest predation and brood parasitism by Brown-headed Cowbirds (Molothrus ater). Brood parasitism levels gradually decreased from 60% to 3% (n = 250 nests) over a distance of 2 km from an agricultural edge proximal to a known cowbird foraging site (a pig feedlot), but they did not vary with distance from any other kinds of edges or with forest stand type. Rates of nest predation (n = 278 nests) did not vary with distance from any edges, but they were significantly lower in older forest than within even-aged clearcuts, a tree plantation, and in successional vegetation adjacent to a residential facility. These results suggest that, even in fragmented landscapes with high overall levels of parasitism and nest predation, management practices within and immediately adjacent to forest tracts can affect the nesting success of some species, but not necessarily as a simple function of distance from edge. For the Kentucky Warbler, our results suggest that a management strategy that avoids even-age silviculture and leaves core stands of older forest far from cowbird feeding areas can increase nesting success to levels similar to those measured in more forested landscapes.

To help fill the gap in detailed knowledge of avian community structure in tropical forests, we undertook a census of a 97-ha plot of floodplain forest in Amazonian Peru. The plot was censused over a 3-mo period spanning the 1982 breeding season. The cooperative venture entailed @?12 person-months of effort. Conventional spot-mapping was the principal method used, but several additional methods were required to estimate the numbers of non-territorial and group-living species: direct counts of the members of mixed flocks, saturation mist-netting of the entire plot, opportunistic visual registrations at fruiting trees, determination of the average size of parrot flocks, color banding of colonial icterids, etc. Two hundred forty-five resident species were found to hold territories on the plot, or to occupy all or part of it. Seventy-four additional species were detected as occasional-to-frequent visitors, wanderers from other habitats, or as migrants from both hemispheres. By superimposing territory maps or the areas of occupancy of individual species, we determined that point (alpha) diversities exceeded 160 species in portions of the plot. About 1910 individual birds nested in 100 ha of this floodplain forest, making up a biomass conservatively estimated at 190 kg/km^2. The total number of breeding birds was equivalent to that in many temperate forests, but the biomass was about five times as great. Predominantly terrestrial granivores contributed the largest component of the biomass (39%), followed by largely arboreal frugivores (22%). Considering only insectivores, the biomass (34 kg/km^2) is somewhat less than that in the forest at Hubbard Brook, New Hampshire (40 kg/km^2), although it is greater (55 kg/km^2) if one includes omnivores. The number of insectivores was considerably less than at Hubbard Brook, due to their 60% larger average body size (32 vs. 20 g). Even though a large majority of the species were patchily distributed, the 97-ha plot was found to include 99% of the bird species that regularly occupy mature floodplain forest at Cocha Cashu. The most abundant species occupied territories of 4-5 ha, and 84 species (26%) had population densities of @<1 pair per square kilometre. Of these, 33 (10% of the total community) were judged to be constitutively rare (i.e., having low population densities everywhere), rather than being merely locally rare. Many of these are predicted to be vulnerable to forest fragmentation and disturbance. Comparison of these results with those from other tropical forests proved difficult due to a lack of standardized methodology.

Most forest birds include arthropods in their diet, sometimes specializing on arthropods that consume plant foliage. Experimental tests of whether bird predation on arthropods can reduce plant damage, however, are few and restricted to relatively low-diversity systems. Here, we describe an experimental test in a diverse tropical forest of whether birds indirectly defend foliage from arthropod herbivores. We also compare how the indirect effects of bird predation vary with different levels of foliage productivity in the canopy vs. the understory. For three Neotropical tree species, we observed that birds decreased local arthropod densities on canopy branches and reduced consequent damage to leaves. In contrast, we observed no evidence of bird-arthropod limitation on conspecific saplings in the less productive understory of the same forest. Our results support theory that predicts trophic cascades where productivity is high and suggest that birds play an important role in Neotropical communities by means of their indirect defense of some canopy tree species.