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Long-term Basis (long-term + basis)
Selected AbstractsPrescribed Burning to Restore Mixed-Oak Communities in Southern Ohio: Effects on Breeding- Bird PopulationsCONSERVATION BIOLOGY, Issue 5 2001Vanessa L. Artman We studied the effects of repeated burning (1,4 years of annual burning) and recovery (1 year after burning,) on the breeding bird community. Burning resulted in incremental but temporary reductions in the availability of leaf litter, shrubs, and saplings, but it did not affect trees, snags, or understory vegetation cover. Of 30 bird species monitored, 4 were affected negatively and 2 were affected positively by burning. Population densities of Ovenbirds ( Seiurus aurocapillus), Worm-eating Warblers ( Helmitheros vermivorus), and Hooded Warblers ( Wilsonia citrina) declined incrementally in response to repeated burning and did not recover within 1 year after burning, suggesting a lag time in response to the changes in habitat conditions. Densities of Northern Cardinals ( Cardinalis cardinalis) fluctuated among years in the control units, but remained low in the burned units. Densities of American Robins ( Turdus migratorius) and Eastern Wood-Pewees ( Contopus virens) increased in response to burning, but these increases were apparent only after several years of repeated burning. In general, burning resulted in short-term reductions in the suitability of habitat for ground- and low-shrub-nesting birds, but it improved habitat for ground- and aerial-foraging birds. Overall, there were no changes in the composition of the breeding-bird community. Total breeding bird population levels were also unaffected by burning. Our results suggest that prescribed burning applied on a long-term basis or across large spatial scales is likely to have adverse effects on ground- and low-shrub-nesting bird species, but other changes in the composition of the breeding-bird community are likely to be minimal as long as the closed-canopy forest structure is maintained within the context of prescribed burning. Resumen: Se está reintroduciendo fuego artificialmente en los bosque del sur de Ohio para determinar su efectividad para restaurar y mantener comunidades de bosques mixtos de encino ( Quercus spp.). Estudiamos los efectos de quemas repetidas (1,4 años de quema anual,) y de recuperación (1 año después de la quema) sobre la comunidad de aves reproductivas. La quema resultó en reducciones temporales en la disponibilidad de hojarasca, arbustos y renuevos, pero no afectó a los árboles, tocones o la cubierta vegetal del sotobosque. De 30 especies de aves monitoredas, 4 fueron afectadas negativamente por la quema y 2 fueron afectadas positivamente. Las densidades de población de Seiurus aurocapillus, de Helmitheros vermivorus y de Wilsonia citrina declinaron incrementalmente en respuesta a quemas repetidas y no se recuperaron en un año después de la quema, sugiriendo un retraso en el tiempo de respuesta a los cambios en las condiciones del hábitat. Las densidades de Cardinalis cardinalis fluctuaron entre años en las unidades control, pero permanecieron bajas en las unidades quemadas. Las densidades de Turdus migratorius y de Contopus virens aumentaron en respuesta a la quema, pero estos incrementos fueron evidentes sólo hasta varios años después de quemas repetidas. En general, en el corto plazo la quema resultó en reducciones en la calidad del hábitat para aves que anidan sobre el suelo y en arbustos bajos, pero mejoró el hábitat para aves que forrajean en el suelo y el aire. En general, no hubo cambios en la composición de la comunidad de aves reproductivas. Los niveles totales de poblaciones de aves reproductivas tampoco fueron afectados por la quema. Nuestros resultados sugieren la posibilidad de que la quema prescrita aplicada a largo plazo o en escalas espaciales grandes tenga efectos adversos sobre especies de aves que anidan sobre el suelo y en arbustos bajos, pero la posibilidad de cambios en la composición de la comunidad de aves reproductivas es mínima. [source] The paleoecology and archaeology of long-term water storage in a Hohokam reservoir, southwestern Arizona, U.S.A.GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 2 2004James M. Bayman Water storage reservoirs were an important feature of economic organization among ancient societies in the North American Southwest. Analyses of reservoir sediments from a Hohokam archaeological site in the Sonoran Desert yielded taxonomic species of ostracodes (microscopic crustaceans) and pollen grains that are indicative of a past water-rich environment. The discovery that this reservoir was capable of storing water on a long-term basis indicates that archaeological models for the region, which have relied on direct historic analogy, must be reexamined. In contrast to the local ethnographic record, paleoecological data generated by this study imply that the Hohokam could establish permanent desert settlements with water storage reservoirs away from perennial rivers and streams. Moreover, residents of these areas were geographically positioned to facilitate the circulation of marine resources (i.e., salt and shell) from the Gulf of California to territories within and beyond the Hohokam region. © 2004 Wiley Periodicals, Inc. [source] The simulation of heat and water exchange at the land,atmosphere interface for the boreal grassland by the land-surface model SWAPHYDROLOGICAL PROCESSES, Issue 10 2002Yeugeniy M. Gusev Abstract The major goal of this paper is to evaluate the ability of the physically based land surface model SWAP to reproduce heat and water exchange processes that occur in mid-latitude boreal grassland regions characterized by a clear seasonal course of hydrometeorological conditions, deep snow cover, seasonally frozen soil, as well as seasonally mobile and shallow water table depth. A unique set of hydrometeorological data measured over 18 years (1966,83) at the Usadievskiy catchment (grassland) situated in the central part of Valdai Hills (Russia) provides an opportunity to validate the model. To perform such validation in a proper way, SWAP is modified to take into account a shallow water table depth. The new model differs from its previous version mainly in the parameterization of water transfer in a soil column; besides that, it includes soil water,groundwater interaction. A brief description of the new version of SWAP and the results of its validation are presented. Simulations of snow density, snow depth, snow water equivalent, daily snow surface temperature, daily evaporation from snow cover, water yield of snow cover, water table depth, depth of soil freezing and thawing, soil water storage in two layers, daily surface and total runoff from the catchment, and monthly evaporation from the catchment are validated against observations on a long-term basis. The root-mean-square errors (RMSEs) of simulations of soil water storage in the layers of 0,50 cm and 0,100 cm are equal to 16 mm and 24 mm respectively; the relative RMSE of simulated annual total runoff is 16%; the RMSE of daily snow surface temperature is 2·9 °C (the temperature varies from 0 to ,46 °C); the RMSE of maximum snow water equivalent (whose value averaged over 18 years is equal to 147 mm) is 32 mm. Analysis of the results of validation shows that the new version of the model SWAP reproduces the heat and water exchange processes occurring in mid-latitude boreal grassland reasonably well. Copyright © 2002 John Wiley & Sons, Ltd. [source] Guided tissue regeneration combined with a deproteinized bovine bone mineral (Bio-Oss®) in the treatment of intrabony periodontal defects: 6-year results from a randomized-controlled clinical trialJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2010Andreas Stavropoulos Stavropoulos A, Karring T. Guided tissue regeneration combined with a deproteinized bovine bone mineral (Bio-Oss®) in the treatment of intrabony periodontal defects: 6-year results from a randomized-controlled clinical trial. J Clin Periodontol 2010; 37: 200,210. doi: 10.1111/j.1600-051X.2009.01520.x. Abstract Aim: To present the 6-year results of a randomized-controlled clinical trial evaluating guided tissue regeneration (GTR) combined with or without deproteinized bovine bone mineral (DBBM) in intrabony defects. Material & Methods: In each of 45 patients, one defect was treated with GTR combined with DBBM hydrated in saline (DBBM,) or gentamicin sulphate (DBBM+) or with GTR alone. Clinical parameters were recorded pre-surgery, at 1 and 6 years postsurgery. Results: Thirty-six patients/33 teeth were available for the 6-year control. Statistically significant clinical improvements were observed for all treatments. Clinical attachment level (CAL) gain averaged 2.5 mm (DBBM,), 4.1 mm (DBBM+), and 3.0 mm (GTR) at 1 year postsurgery, and remained stable over 5 additional years (2.3, 4.1, and 2.7 mm, respectively). Treatment did not appear to influence residual probing depths (PDs) or CAL gains at 6 years postsurgery, or the extent of PD and CAL change from 1 to 6 years, and did not associate with sites losing CAL during follow-up. No association of grafting with sites showing CAL gain 4 mm at the 1- or 6-year control was observed. Conclusion: The improvements in periodontal conditions obtained after GTR treatment with or without the adjunct use of DBBM can be preserved on a long-term basis. [source] Long-term stability of periodontal conditions achieved following guided tissue regeneration with bioresorbable membranes: case series results after 6,7 yearsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2004Andreas Stavropoulos Abstract Objectives: To evaluate the results of guided tissue regeneration (GTR) treatment of intrabony defects with bioresorbable membranes after 6,7 years, and to disclose factors that may influence the long-term outcome of the treatment. Methods: Twenty-five defects in 19 patients were treated by means of polylactic acid/citric acid ester copolymer bioresorbable membranes. At baseline and after 1 and 6,7 years, the following parameters were recorded: (1) probing pocket depth (PPD), (2) gingival recession (REC), (3) probing attachment level (PAL)=PPD+REC, (4) presence/absence of plaque (PI), (5) presence/absence of bleeding on probing (BOP). Smoking habits and frequency of dental-control visits were also recorded. Significance of differences between categorical variables was evaluated with McNemar's test, and between numerical variables with the t -test for paired observations. Generalized linear models were constructed to evaluate the influence of various factors on PAL gain and PPD changes from 1 to 6,7 years. Association of smoking, frequency of dental controls, oral hygiene, and BOP with sites losing 2 mm in PAL was evaluated with Fisher's exact test. Results: At baseline, a mean PPD of 8.7±1.1 mm and a mean PAL of 9.8±1.5 mm was recorded. Statistically significant clinical improvements were observed at 1 and 6,7 years after GTR treatment. An average residual PPD of 3.8±1.1 mm and a mean PAL gain of 3.8±1.4 mm were observed after 1 year. After 6,7 years the corresponding values were 4.7±1.3 and 3.6±1.4 mm, respectively. There were no statistically significant differences between the 1- and the 6,7-year values. At the 6,7-year control, only 16% of the sites had lost 2 mm (maximum 3 mm), of the PAL gain obtained 1 year after GTR treatment. None of the sites had lost all of the attachment gained 1 year after treatment. Smoking, frequency of dental controls, oral hygiene, and BOP did not seem to influence the change of PPD and PAL gain, or the stability of PAL gain (i.e. losing PAL or not) from 1 to 6,7 years from treatment. Conclusion: Clinical improvements achieved by GTR treatment of intrabony defects by means of bioresorbable membranes can be maintained on a long-term basis. [source] Pesticides and the intoxication of wild animalsJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 2 2007P. BERNY Pesticides are widely used to control agricultural pests. Unfortunately, because of their biological activity, they may have detrimental effects on nontarget species. Acute toxicity, resulting in death, is reported worldwide. Although chronic and indirect effects may be even more hazardous for animal populations on a long-term basis, they are usually evaluated as parts of research programs. The purpose of this paper was to review the wildlife-poisoning surveillance systems and their results regarding the circumstances of exposure of wild animals, the pesticides involved and the species exposed. Most data are retrieved from the British and French pesticide poisoning surveillance systems in wildlife, with some data from other European structures. [source] Long-term evaluation of animal-assisted therapy for institutionalized elderly people: a preliminary resultPSYCHOGERIATRICS, Issue 1 2007Namiko KAWAMURA Abstract Background:, Many researchers theorize that animal-assisted therapy (AAT) will have an effect on people suffering from the symptoms of dementia by evaluating short-term-effects. The purpose of this research was to evaluate the psychological and behavioral effects of AAT on elderly residents of a nursing home on a long-term basis. Methods:, The subjects consisted of 10 residents of a residential nursing home. Researchers first created each participant's goal in an agreement with the nursing home staff. Visits were made twice a month, and on each occasion three or four dogs were taken. The residents were able to freely feed, hold and play with the dogs, with each dog placed on a separate table. Data collection methods included GBS Scale Japanese Version (GBSS-J) and Mental Function Impairment Scale (MENFIS). Data was collected four times during the period 2003,05. The scores were analyzed using SPSS11.5J. Results:, According to GBSS-J, the scores for intellectual function, spontaneity, emotional function and other mental functions decreased during the first 6 months of the study and then increased until the twelfth month. The score for Motor function increased over the 12 months. When comparisons were made item by item, there were significant decreases in impaired orientation in space, and emotional liability during the first 6 months. According to MENFIS, the overall score tended to decrease during the first 6-month period but increased from 6 months to 12 months. There was a tendency for scores to decrease in impaired emotional function, especially impaired suitability of emotional expression and impaired stability of emotional expression over the 12-month period. Conclusions:, After 6 months of participation in AAT, there were improvements in mental functions, though physical functions decreased. It is suggested that after a 6 month period each subject's needs and goals should be re-examined. [source] | ||||||||||