Cumulative effects of roads and logging on landscape structure in the San Juan Mountains,Colorado (USA)

In the southern Rocky Mountains of temperate North America, the effects of Euro-American activities on disturbance regimes and landscape patterns have been less ubiquitous and less straightforward in high-elevation landscapes than in low-elevation landscapes. Despite apparently little change in the natural disturbance regime, there is increasing concern that forest management activities related mainly to timber harvest and to the extensive network of roads constructed to support timber harvest, fire control, and recreation since the late 1800s have altered disturbance regimes and landscape structure. We investigated the magnitude of change in landscape structure resulting from roads and logging since the onset of timber harvest activities in 1950. We found limited evidence for significant impacts in our study area when all lands within the landscape were considered. The relatively minor changes we observed reflected the vast buffering capacity of the large proportion of lands managed for purposes other than timber (e.g., wilderness). Significant changes in landscape structure and fragmentation of mature forest were, however, evident on lands designated as suitable timberlands. Roughly half of the mature coniferous forest was converted to young stands; mean patch size and core area declined by 40% and 25%, respectively, and contrast-weighted edge density increased 2- to 3-fold. Overall, roads had a greater impact on landscape structure than logging in our study area. Indeed, the 3-fold increase in road density between 1950–1993 accounted for most of the changes in landscape configuration associated with mean patch size, edge density, and core area. The extent of area evaluated and the period over which change was evaluated had a large impact on the magnitude of change detected and our conclusions regarding the ecological significance of those changes. Specifically, the cumulative impact on landscape structure was negligible over a 10-year period, but was notable over a 40-year period. In addition, the magnitude of change in landscape structure between 1950–1993 varied as a function of landscape extent. At the scale of the 228000 ha landscape, change in landscape structure was trivial, suggesting that the landscape was capable of fully incorporating the disturbances with minimal impact. However, at intermediate scales of 1000–10000 ha landscapes, change in landscape structure was quite evident, suggesting that there may be an optimal range of scales for detecting changes in landscape structure within the study area.     

Potential Utilization of Green Tide-Forming Macroalgae from Patos Lagoon,Rio Grande-RS,Brazil

ABSTRACT

This study was conducted to evaluate the biochemical and nutritional characteristics of naturally occurring estuarine macroalgae in the Patos Lagoon (Rio Grande, Brazil). The study of these macroalgae, dominated by Ulva and Cladophora species, contributes to current research on the potential utilization of green tide-forming algae. Although high levels of carotenoids (378 ± 0.02 µg g^?1) and antioxidant activity (75.0% for DPPH) were found in the naturally occurring macroalgae, these macroalgae cannot be used in the food industry due to the presence of toxic levels of arsenic (exceeding the thresholds of both French and Brazilian legislation for food). Regarding the potential of the studied macroalgae as a biofuel source, the low lipid and very high carbohydrate contents suggest a possible use in the fermentation of ethanol, butanol, or methane.     

Responses of day-neutral,June-bearing and everbearing strawberry cultiv ars to gibberellic acid and phthalimide treatments

Field grown day-neutral, June-bearing and everbearing strawberry cultivars responded similarly to GA₃ in most cases. GA₃ stimulated daughter-plant production in ‘Hecker’ (DN) and suppressed it in ‘Guardian’ (June). Fifty mg l^?1 GA₃ increased initial runner production of all cultivars, while both 50 and 100 mg l^?1 GA₃ increased fruit yield the year following treatment. In greenhouse studies, GA₃ initially increased leaf number, petiole length and runner production, but the effects diminished with time. Phthalimide at 1000 mg l^?1 was most effective in increasing leaf number.     

Ultrasonographic examination of injuries to the achilles tendon in dogs and cats.

The value of ultrasonography in the diagnosis of lesions of the Achilles tendon was Investigated in 42 dogs and seven cats. A standardised four-part ultrasonographic examination was established. Linear transducers with a frequency of more than 7.5 MHz were used. Ultrasonography allowed identification and differentiation of total ruptures and the differentiation of partial ruptures into deep or superficial ruptures, or those comprising muscular tears. The healing process could be monitored and imaged using this technique. Suture material was readily visible in surgically treated cases. Displacement of the superficial digital flexor tendon could be identified. In such cases, the tendon tissue was seen either medially or laterally to the calcaneus. The healing process of the Achilles tendon could also be documented using ultrasonography. However, it was not possible to determine the age of the injury and the exact end of the healing process. Ultrasonography therefore proved to be an excellent diagnostic method for imaging lesions of the Achilles tendon and associated injuries in dogs and cats. After physical examination, the technique should be the next logical step in the evaluation of a suspected injury to the Achilles tendon.     

Lomustine and prednisone as a first-line treatment for dogs with multicentric lymphoma: 17 cases (2004-2005)

OBJECTIVE: To assess response rate, median duration of response, adverse effects, and prognostic factors associated with concurrent administration of lomustine and prednisone as a first-line treatment for dogs with multicentric lymphoma. DESIGN: Retrospective case series. ANIMALS: 17 dogs. PROCEDURES: Medical records were reviewed. Information obtained included signalment, physical examination findings, results of diagnostic testing, stage and substage, initial lomustine and prednisone dosages, and total number of lomustine doses administered. RESULTS: Lomustine was administered at a median starting dosage of 67 mg/m(2), PO, every 21 days until 5 doses were given or disease progression was observed. Prednisone was administered at a median starting dosage of 1.8 mg/kg/d (0.82 mg/lb/d), PO, with dosage tapered during the first month of treatment. Six dogs had a complete response, and 3 had a partial response. Mean and median durations of response were 48.8 and 39.5 days, respectively. Median survival time was 111.2 days. In multivariate analyses, female sex and higher total lomustine dose were significantly associated with a longer disease-free inter-val. Neutropenia was the dose-limiting factor, with 4 dogs developing clinically important neutropenia 1 week after administration of a dose of lomustine. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that concurrent treatment with lomustine and prednisone was well tolerated in dogs with multicentric lymphoma, but findings did not support the use of this combination for first-line treatment of affected dogs.     

Decreased systolic function and inadequate hypertrophy in large and small breed dogs with chronic mitral valve insufficiency

BACKGROUND: Systolic dysfunction associated with chronic mitral valve insufficiency (CMVI) has been demonstrated in experimental animal models and large breed (LB) dogs but has been reported as an uncommon finding in small breed (SB) dogs with naturally occurring disease. It has been suggested the myocardial failure could be, in part, because of an insufficient increase in left ventricular mass. HYPOTHESIS: To test if SB and LB dogs with CMVI and moderate heart failure have systolic dysfunction and if they have adequate eccentric hypertrophy. ANIMALS: Data from 38 SB and 18 LB dogs affected with CMVI were compared retrospectively with results from 2 groups of normal dogs (17 SB and 32 LB). METHODS: Systolic function was investigated echocardiographically by using percentage fractional shortening (FS), the ratio between observed and expected end-systolic diameter (ESD/ESDe), and end-systolic volume index (ESVI). Left ventricular hypertrophy was estimated by using the ratio between the thickness of the left ventricular free wall and the radius in diastole (h/R). RESULTS: Both affected SB and LB dogs had a significantly increased FS and ESVI (FS% SB 45.6 + 8.04 versus 40.06 + 8.9, P < .05; FS% LB 33.64 + 8.61 versus 27.3 + 7.3 P < .05; ESVI SB 30.0 +/- 2.3 mL/m2 versus 21.18 +/- 13.9 mL/m2, P < .05; ESVI LB 83.22 +/- 43.84 mL/m2 versus 36.43 +/- 13.30 mL/m2 versus P < .001). The h/R in affected animals was decreased (0.53 +/- 0.11 versus 0.41 +/- 0.12, P < .05 SB; 0.47 +/- 0.11 versus 0.38 +/- 0.09, P < .05, LB). CONCLUSIONS AND CLINICAL IMPORTANCE: Data from this study indicate that dogs with moderate heart failure caused by CMVI have systolic dysfunction. Inadequate hypertrophy of the left ventricle may be, in part, responsible for this finding.     

Genotypic versus phenotypic identification of staphylococcal species of canine origin with special reference to Staphylococcus schleiferi subsp. coagulans

A comparative study was performed to examine the respective accuracy of 16S rDNA sequencing and of the commercial biochemical assay ID32 STAPH (bioMérieux, Marcy l'Etoile, France) in the identification of 232 staphylococcal samples representing 20 species and subspecies isolated from 367 dogs. Notable differences in species distribution were observed by comparing genotypic and phenotypic data. Partial sequencing of 16S rDNA resulted in an unambiguous identification of 226 (97.4%) of the isolates, whereas the phenotypic approach resulted in a correct diagnosis of 162 (69.8%) of the isolates. Statistical agreement between genotypic and phenotypic identification of staphylococci was substantial (Kappa coefficient of 0.6-0.8) for Staphylococcus aureus, S. hominis, S. warneri, S. cohnii subsp. urealyticus, and S. simulans, and "almost perfect" (Kappa coefficient of 0.8-1) for S. intermedius, S. epidermidis, S. equorum, S. haemolyticus, S. sciuri, and S. kloosi. No agreement above that expected by chance (Kappa coefficient=0) was observed for S. schleiferi subsp. coagulans, which was either confounded with S. intermedius and S. capitis, or categorized as unacceptable by the biochemical assay. Given the growing importance of this pathogen in veterinary medicine and its frequent misidentification with related staphylococci, a PCR-RFLP approach producing a S. schleiferi-specific restriction profile was developed. This fast and reliable assay represents a valuable tool in assisting in the monitoring of this pathogen.     

Infection of sandflies by a cat naturally infected with Leishmania infantum

Despite the recent reports of feline leishmaniosis from Southern Europe, cats are still regarded as unusual Leishmania hosts. A cat found chronically infected with Leishmania was submitted to xenodiagnosis. After being sedated, the animal was exposed to the bite of 100 laboratory-reared Phlebotomus perniciosus in a fine net cage for 90 min. Four out of 19 blood-fed sandflies (21%) showed motile promastigotes at the dissection. Parasites cultured from cat's lymph node and an infected fly were identical at PCR-RFLP genotyping and identified as Leishmania infantum MON-1, the main zymodeme responsible for human and canine leishmaniosis in Southern Europe. This is the first evidence of transmissibility of feline parasites to a proven vector, suggesting that cats may represent an additional domestic reservoir for L. infantum.     

Soil function assessment in high-mountain environments: Testing the SEPP tool in a ski resort in the Italian Alps

Soil function assessment (SFA) plays an important role in evaluating the impact of management practices, land-use changes and construction work. The Soil Evaluation for Planning Procedures (SEPP) tool is one of the few existing SFA tools that allow automated SFA. It was originally developed to address land-use planning issues, which traditionally play a minor role in high-mountain areas. Hence, the SEPP tool has not yet been applied to such environments. In this study, we tested the SEPP performance on high-mountain soils previously altered by construction work and land-use changes. Specifically, we evaluated soil data from 16 ski runs and 16 paired control sites in the Italian Alps, aiming to reflect land-use-driven differences in soil properties in the SFA results. The study revealed options to adapt SEPP assessment methods if high-mountain soils with special characteristics (e.g. shallowness or high coarse fragment content) are investigated. The main adaptation options are the consideration of further soil parameters and the adjustment of thresholds of function fulfilment levels. However, the assessment results of the current SEPP version already reflect the most relevant impacts of ski run construction on the soils in the study area: fulfilment of some of the soil functions was impaired and that of others improved, while most remained at a comparable level. We conclude that SFA with the SEPP tool provides valuable support for the evaluation of construction projects and land-use change in high-mountain environments. However, the significance of SFA can be improved by considering the intrinsic properties of high-mountain soils.