Triage for conserving populations of threatened species: The case of woodland caribou in Alberta

Prioritization of conservation efforts for threatened and endangered species has tended to focus on factors measuring the risk of extirpation rather than the probability of success and cost. Approaches such as triage are advisable when three main conditions are present: insufficient capacity exists to adequately treat all patients, patients are in a critical state and cannot wait until additional capacity becomes available, and patients differ in their likely outcome and/or the amount of treatment they require. The objective of our study was to document the status of woodland caribou (Rangifer tarandus) herds in Alberta, Canada, with respect to these three conditions and to determine whether a triage approach might be warranted. To do this we modeled three types of recovery effort - protection, habitat restoration, and wolf control - and estimated the opportunity cost of recovery for each herd. We also assessed herds with respect to a suite of factors linked to long-term viability. We found that all but three herds will decline to critical levels (<10 animals) within approximately 30 years if current population trends continue. The opportunity cost of protecting all ranges by excluding new development, in terms of the net present value of petroleum and forestry resources, was estimated to be in excess of 100 billion dollars (assuming no substitution of activity outside of the ranges). A habitat restoration program applied to all ranges would cost several hundred million dollars, and a provincial-scale wolf control program would cost tens of millions of dollars. Recovery costs among herds varied by an order of magnitude. Herds also varied substantially in terms of their potential viability. These findings suggest that woodland caribou in Alberta meet the conditions whereby triage should be considered as an appropriate conservation strategy.     

Two-season study of the influence of regulated deficit irrigation and reflective mulch on individual and total phenolic compounds of nectarines at harvest and during storage

The influence of deficit irrigation (Deficit) and reflective mulch (Reflective) of Caldesi 2000 nectarines on the content of individual phenolic compounds was studied at harvest and during storage for 2, 4, and 6 weeks at 2 °C during two consecutive years (2007 and 2008). Individual phenolic groups in the edible fruit part consisted mainly of proanthocyanidins (200 mg/100 g fw), lower content of phenolic acids (17 mg/100 g fw), and minor content of flavonols (5 mg/100 g fw) and anthocyanins (1.2 mg/100 g fw). Deficit irrigation increased the content of total phenolics, including proanthocyanidins and phenolic acids, reaching similar amounts in both years. Sun-exposed fruit (upper part of canopy) showed higher content than shaded fruit (lower part of canopy). However, Reflective significantly increased the content of total phenolics, particularly phenolic acids and proanthocyanidins, of fruit located in the lower part of the canopy. During storage, Deficit and Reflective did not affect the content of phenolic acids, flavonols, and proanthocyanidins when compared to the content at harvest. Optimizing cultural practices can be a way to increase the phenolic content of nectarines.     

Nature and origin of stone stripes on the Columbia Plateau

Beds of size-sorted stones forming stripes perpendicular to the contour are conspicuous on hillsides of the Columbia Plateau. Stripes occur on terrain ranging from 0° to about 30° in steepness, often beginning among Mima-type mounds on mesa tops and extending downward onto steep, unmounded slopes. Four mechanisms of their origin have been hypothesized: 1) water erosion, 2) solifluction and soil creep, 3) weathering of rock outcrops, and 4) tunneling by pocket gophers. We measured characteristics of five stripes on slopes of differing exposure and steepness. These stripes were 58–124 m long, and widths showed a maximum range of 0.55–3.70 m. Data on physical and biotic characteristics of the stripes suggest that pocket gopher tunneling is a basic mechanism of stripe formation on gentle slopes, and that this mechanism is augmented by outcrop weathering and colluvial dynamics on steeper slopes, with erosion playing a secondary role.     

Producing progeny from endangered birds of prey: treatment of urine-contaminated semen and a novel intramagnal insemination approach.

Wild raptors brought into an ex situ environment often have poor semen quality that is further compromised by urine contamination. Generally, it is believed that in birds, artificial insemination into the cloaca or caudal vagina of females requires large doses of high-quality spermatozoa to maximize fertility. In an effort to define and overcome some of the challenges associated with reproduction in wild raptors, the objectives of this study were to 1) evaluate the frequency, impact, and remediation of urine contamination in fresh ejaculates for the purpose of maintaining sperm motility and viability in vitro, and 2) develop a deep insemination method that allows low numbers of washed sperm to be placed directly into the magnum to increase the probability of producing fertilized eggs. The species evaluated include golden eagle (Aquila chrysoetos), imperial eagle (A. adalberti), Bonelli's eagle (Hiernaetus fasciatus), and peregrine falcon (Falco peregrinus). Semen samples were collected and pooled by species, and a minimum of 25 pooled ejaculates per species were evaluated for urine contamination, pH, sperm viability, and sperm motility; the samples were either unwashed or washed in neutral (pH 7.0) or alkaline (pH 8.0) modified Lake's diluent. Female golden eagles and peregrine falcons were inseminated via transjunctional, intramagnal insemination with washed spermatozoa from urine-contaminated samples. Urine contamination occurred in 36.8 +/- 12.8% (mean +/- SEM) golden eagle, 43.1 +/- 9.1% imperial eagle. 28.7 +/- 16.1% Bonelli's eagle, and 48.2 +/- 17.3% peregrine falcon ejaculates. The pH in urine-contaminated semen samples ranged from 6.48 +/- 0.3 to 6.86 +/- 0.2, and in noncontaminated samples it ranged from from 7.17 +/- 0.1 to 7.56 +/- 0.1. Sperm viability and motility were reduced (P < 0.05) in all species for unwashed vs. washed sperm after 30 min incubation at room temperature. Two peregrine falcon chicks and one golden eagle chick hatched after intramagnal insemination. This study demonstrates that urine contamination, a common and lethal acidifier in manually collected raptor ejaculates, can be circumvented by immediate, gentle seminal washing. Furthermore, these processed sperm, when deposited by transjunctional intramagnal insemination, can produce live young.     

Lasers and laser-tissue interaction.

Light produced by a laser differs from incandescent light in that it is monochromatic, coherent, and intense; and it is these properties that allow lasers to be used as such unique tools in biomedical research and patient care. The effect of a laser beam on tissue is dependent on the optical and mechanical properties of the tissue, and the wavelength, power parameters, and time domains of the laser exposure. Understanding these principles is not only important for the selection of an appropriate laser system for a specific application, but also is essential for that application to be successful.     

Relationships between landcover proportion and indices of landscape spatial pattern

Recent studies have related percolation theory and critical phenomena to the spatial pattern of landscapes. We generated simulated landscapes of forest and non-forest landcover to investigate the relationship between the proportion of forest (P_i) and indices of patch spatial pattern. One set of landscapes was generated by randomly assigning each pixel independently of other pixels, and a second set was generated by randomly assigning rectilinear clumps of pixels. Indices of spatial pattern were calculated and plotted against P_i. The random-clump landscapes were also compared with real agricultural landscapes. The results support the use of percolation models as neutral models in landscape ecology, and the performance of the indices studied with these neutral models can be used to help interpret those indices calculated for real landscapes.     

Comparison of core needle biopsy and fine-needle aspiration of enlarged peripheral lymph nodes for antemortem diagnosis of enzootic bovine lymphosarcoma in cattle

OBJECTIVE: To determine whether antemortem core needle biopsy and fine-needle aspiration of enlarged peripheral lymph nodes could be used to distinguish between inflammation and lymphosarcoma in cattle. DESIGN: Prospective study. ANIMALS: 25 cattle with enlarged peripheral lymph nodes. PROCEDURES: Antemortem biopsies of the selected lymph nodes were performed with an 18-gauge, 12-cm core needle biopsy instrument. Fine-needle aspirates were performed with a 20-gauge, 4-cm needle. Specimens were analyzed by pathologists who were unaware of clinical findings and final necropsy findings, and specimens were categorized as reactive, neoplastic, or nondiagnostic for comparison with necropsy results. RESULTS: Sensitivity and specificity of core needle biopsy ranged from 38% to 67% and from 80% to 25%, respectively. Sensitivity of fine-needle aspiration ranged from 41% to 53%, and specificity was 100%. Predictive values for positive test results ranged from 77% to 89% for core needle biopsy and were 100% for fine-needle aspiration. Predictive values for negative test results were low for both core needle biopsy and fine-needle aspiration. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that core needle biopsy and fine-needle aspiration can aid in the antemortem diagnosis of bovine enzootic lymphosarcoma. Results of fine-needle aspiration of enlarged peripheral lymph nodes were more specific and more predictive for a positive test result than were results of core needle biopsy.