Search

Abstract Ecosystem‐based forest management requires long planning horizons to incorporate forest dynamics — changes resulting from vegetation growth and succession and the periodic resetting of these by natural and anthropogenic disturbances such as fire, wind, insects, and timber harvests. Given these dynamics, ecosystem‐based forest management plans should specify desired conditions such as tree species composition, age class, tree density and structure, size and density of snags and course woody debris, and the size, shape, and juxtaposition of trees, groups of trees, and stands in order to create and sustain habitats for wildlife. The management recommendations for the northern goshawk (Accipiter gentilis) in the southwestern United States (hereafter, recommendations; Reynolds et al. 1992) is a management plan designed to conserve this top predator by accounting for factors thought to limit their populations: vegetation structures, foods, predators, and competitors. The recommendations combined coarse‐ and fine‐filter approaches to develop desired habitats for goshawks and their prey in landscapes whose compositions, structures, and patterns were conditioned on the aut‐ and synecologies of over‐ and understory plant species in forest ecosystems. Management plans that address all stages of a species' life history, the physical and biological factors limiting its populations, the habitats of other members of its ecological community, and the spatial and temporal dynamics of forests it occupies should be robust to failure (Reynolds et al. 2006a, b). The recommendations have been implemented in National Forests in the southwestern United States since 1996 (USDA Forest Service 1996), but their efficacy at conserving goshawk reproduction and survival has yet to be demonstrated. Recently, Beier et al. (2008) conducted a test of the recommendations and concluded that reproduction of goshawks declined as forest structures in their breeding areas became increasingly similar to those described in the recommendations. Here we show that methods they used to determine similarity to the structural conditions described in the recommendations resulted in inappropriate measures of similarity. We also show that their monitoring of goshawk reproduction on the 13 breeding areas used in their study was insufficient, and show how their insufficient monitoring introduced a systematic bias that reduced the precision of their test even if they had correctly measured similarity. We end by suggesting approaches for determining structural similarity to the goshawk recommendations in ponderosa pine and how to achieve adequate sampling for reproduction on breeding areas. © 2012 The Wildlife Society.

We responded to the claim by Greenwald et al. (2005) that the management recommendations for the northern goshawk in the Southwestern United States (MRNG; Reynolds et al. 1992), a food web-based conservation plan that incorporated both northern goshawk (Accipiter gentilis) and multiple prey habitats, may be inadequate to protect goshawks. Greenwald et al. (2005) based this claim on their review of 12 telemetry studies of goshawk habitat selection and 5 nontelemetry studies of the effects of vegetation structure at the home range scale on goshawk nest occupancy and reproduction that appeared after the 1992 publication of the MRNG. Greenwald et al. (2005) summarized their review as showing that 1) goshawks were habitat specialists limited to forests with mature and old-growth structures including large trees, high canopy cover, multiple canopy layering, and abundant woody debris; 2) habitats were not selected on the basis of prey abundance and, therefore, managing for prey habitats diluted goshawk habitats; and 3) selection for openings, edges, and habitat diversity was inconclusive. Our review found that when the studies' respective authors pooled their radiotagged goshawks there were weak to strong selections for old forest structures. However, the studies also documented extensive variation in use of vegetation types and structures by individual goshawks; some avoided openings, edges, young forests, and old forests, whereas others selected for these characteristics. Additionally, by virtue of their wide geographic distribution, the studies showed that the focal populations themselves occurred in a variety of forest types, some with large structural differences. We found no evidence in Greenwald's et al. (2005) review that the MRNG are inadequate to protect goshawks. Rather, the studies reviewed by Greenwald et al. (2005), as well as many studies they missed, supported the MRNG. The suggestion of inadequacy by Greenwald et al. (2005) appeared rooted in misunderstandings of goshawk habitats described in the MRNG, a discounting of the extent of variation in vegetation structural and seral stages used by goshawks, a limited understanding of the extent to which prey limits goshawks, a failure to recognize the dynamic nature of forests, and an incomplete review of the literature. We believe the MRNG are adequate because they maximize the sustainable amount of mature and old forests in goshawk home ranges and specify the kinds and intermixtures of prey habitats within home ranges. Implementation of MRNG should reduce the likelihood that the availability of vegetation structures suited to goshawk nesting and foraging, as well as abundance and availability of prey, will limit goshawk nest occupancy and reproduction. [ABSTRACT FROM AUTHOR]

Unlabelled: This study evaluated the prevalence of upper respiratory symptoms (URS) among patients with symptomatic gastroesophageal reflux disease (GERD). Seventy-four subjects with heartburn completed a URS questionnaire before dual-probe, 24-h esophageal pH monitoring. The URS questionnaire was also completed by 74 normal volunteers without previous or current symptoms of GERD. Esophageal pH monitoring results were classified as normal, distal, or proximal and distal gastroesophageal reflux using standardized criteria. Mean URS scores (+/- SD) were 8.31 +/- 3.98 in the 52 subjects with GERD and 4.57 +/- 3.57 in the 22 subjects with negative pH probe studies, p = 0.02. Subjects with negative pH probe studies and normal volunteers scored similarly on the URS questionnaire. Reflux episodes/24 h correlated with URS scores, r = 0.47, p = 0.0001. Seventy-five percent of subjects with upper reflux, 68% of subjects with lower reflux, 36% of subjects with normal esophageal pH studies, and 9% of normal volunteers reported laryngeal symptoms for at least 5 d/mo. Sixty-nine percent of subjects with upper reflux, 50% of subjects with lower reflux, 31% of subjects with normal pH studies, and 14% of normal volunteers reported nasal symptoms for at least 5 d/mo. URS are frequent among subjects with GERD., Keywords: rhinitis; upper airway; gastroesophageal reflux

BACKGROUND: Cure of patients with esophageal cancer has remained rare over the past four decades. The overall five-year survival rate for squamous cell and adenocarcinoma of the esophagus currently is reported as 12% in whites and 8% in blacks. The five-year survival rate for localized disease at initial staging is only 26% for whites and 13% for blacks. With regional involvement, these rates are 11% and 7%, respectively. METHODS: The author reviews the literature on optimal endoscopic lumen restoration techniques, including dilation, thermal laser and chemical ablation, photodynamic therapy, and stents. Procedures for pain relief and nutritional support are also presented. RESULTS: Lumen restoration to relieve dysphagia and provide the opportunity for sustaining reasonable peroral nutrition is an essential element in the overall management. Nonsurgical lumen restoration procedures have much to offer for dysphagia palliation and are briefly reviewed in this presentation. The major options include ablation of intraluminal tumor mass by thermal laser, photodynamic laser, chemical ablation, peroral dilation, and placement of esophageal stents. Most patients require more than one palliative method to sustain lumen patency during the course of their disease. CONCLUSIONS: Most patients with esophageal cancer will require palliation for the multiple problems that develop during their limited life span. The responsibility of the palliation therapist is to provide the patient with safe and cost-effective treatments that provide the best possible dysphagia relief.

Following the production of digitalis toxicity in dogs as manifested by ventricular tachycardia, the pharmacokinetics of lidocaine treatment of the arrhythmia were determined during pentobarbitone anaesthesia and pentobarbitone-halothane anaesthesia. The elimination rate constants, beta and Ke, and the biological half life T1/2beta were statistically significantly increased during halothane anaesthesia. The volume of distribution was unchanged. The results indicate that the therapeutic loading dose of lidocaine need not be altered during halothane anaesthesia but if a constant infusion is used, the rate of infusion would have to be decreased four fold to avoid toxic plasma levels of lidocaine.

Motility acted as a strong positive selection for nonmucoid Pseudomonas aeruginosa in unshaken cultures. Consistent with this finding, electron microscopic examination of mucoid and nonmucoid revertant strains indicated that the mucoid cells were nonflagellated whereas the nonmucoid revertants were flagellated.

Vitamin supplementation for dialysis patients is still controversial. In our study, we followed longitudinally over a period of a year, 15 patients on chronic hemodialysis who were deprived of vitamin supplementation. Microbiological assays were used to determine the levels of five vitamins of the B group (folate, niacin, B12, B6, and thiamine). Vitamin C was measured chemically. During the observation period when vitamins were not supplemented, a marked drop of many of these vitamins in blood levels were encountered. For vitamins B12 and C, the plasma levels remained within the normal range in all the subjects studied. For the other vitamins, the blood levels were found to be low in a few patients. Our data suggest that vitamin supplementation is probably not needed in most stable hemodialysis patients as it is recommended now, and that perhaps, if supplementation is indicated, less should be given than is presently prescribed. Further research is needed in this area.

Bis-[p-nitrophenyl] phosphate, BNPP, an enzyme inhibitor of the organophosphate class, has been used to inhibit the enzyme, carboxylic ester hydrolase EC 3.1.1.1. Esterases play a major role in the rapid metabolism of propanidid in vivo; in fact, the short duration of action of this intravenous anesthetic agent is due to this rapid hydrolysis. The duration of anesthesia with propanidid alone in healthy mongrel dogs was 10.1 +/- 2.1 (SEM) minutes. When the dogs were pretreated with BNPP, propanidid anesthesia time was prolonged to 38.2 +/- 7.9 (SEM) minutes. Measurements of serum propanidid concentration demonstrated that prolonged high levels of propanidid were associated with the extended anesthesia time. Therefore, BNPP can significantly alter the anesthetic action of propanidid by inhibition of the enzyme system responsible for the rapid hydrolysis of the agent. The experimental model used in the present study provides a means for investigation of effects of certain drugs when their metabolism is impaired.

We investigated the effects of cations on the stability in culture of mucoid strains pf Pseudomonas aeruginosa isolated from patients with cystic fibrosis by studying their effects on the selection of nonmucoid derivatives which arise by spontaneous mutation in cultures of mucoid organisms. Calcium ion concentrations in the range 0.55 to 1.85 mM had no effect on the growth or stability of the mucoid cultures. Higher levels (5.0 mM) inhibited the growth of both mucoid and nonmucoid cells. Likewise, magnesium ion in concentrations of 0.3 to 3.0 mM had no effect. The concentration of iron (either Fe2+ or Fe3+) had a profound effect on the selection of nonmucoid mutants in unshaken cultures of mucoid organisms. In medium containing 0.01 mM iron, nonmucoid mutants rapidly accumulated to a greater than 100-fold-higher frequency than the mucoid forms. Rates of accumulation of nonmucoid derivatives were lower in media containing lower concentrations of iron. The possible role of iron in the selection of nonmucoid cells from a population of mucoid P. aeruginosa is discussed.