bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alteration of salt marsh plant community composition by grazing snow geese
Authors: Smith Thomas J. 
Published: July 2006

A notable omission from wetlands ecology has been the study of the influence of herbivores on vegetation. Reported here are the effects of grazing by snow geese Anser caerulescens altantica on the vegetation of salt marshes along the mid‐Atlantic coast of the United States, Exclosures were used to compare total and species percent cover between grazed and ungrazed areas in three marshes (Salt Flats, South Pond, and Bodie Island) with differing vegetation communities from 1978 to 1980. Spartina alterniflora was reduced by ⅔ in grazed versus ungrazed areas of Salt Flats, S. S. patens was reduced by ½ in grazed portions of South Pond but recovered when grazing ceased. In grazed portions of Bodie Island total plant cover was reduced by 16%. Scirpus robustus and S. patens reacted in opposite ways to grazing pressure with S. robustus increasing and S. patens decreasing, Elocharis was found only in grazed areas of Bodie Island. Echinochloa crusgali appeared in grazed portions of this marsh in 1978 but decreased in abundance during subsequent years. Scirpus americanus was unaffected by grazing, maintaining a nearly constant percent cover in grazed and ungrazed areas at Bodie Island.Differences in responses to grazing are discussed in terms of each species' growth and reproductive strategies as tempered by the physical and biological environment within each marsh.
Digestibility and retension of food components in caged mountain hares Lepus timidus during the winter
Authors: Pehrson Åke 
Published: July 2006

Adult mountain hares in outdoor cages were studied in order to evaluate the consumption and the digestibility of natural winter foods. Food, feces and urine were analysed for nitrogen, phosphorus, calcium, potassium, magnesium and sodium, and food and feces for fiber as well. The metabolism of the different nutrients are presented in this paper.When energy equilibrium was maintained hares assimilated as an average 21.6 g dry matter per kg body weight and day (29.5 g kg0‐75). The fiber fraction showed a low digestibility ranging from 10 to 30% between different food species.At energy equilibrium nitrogen equilibrium was usually also achieved; the hares then digested approximately 0.20–0.25. g nitrogen per kg body weight and day (0.27–0.34 kg ‐0.75). The apparent nitrogen digestibility was low, usually below 40%.The demand for calcium, potassium and magnesium seemed to be well covered via the food. Phosphorus on the other hand was absorbed in small amounts only, which may sometimes have been insufficient. A negative sodium balance occurred when the hares were fed heather or the finest twigs of birch. Due to the low concentrations in the food this could create problems in the supply of sodium.
Effects of forest regeneration on the structure of bird communities in northern Finland
Authors: Hello Pekka 
Published: July 2006

Breeding bird communities in five stages of secondary forest succession were studied in northeastern Finland in 1980–82. Three groups of communities were distinguished: open land, brush phase and forest communities, dominated by Motacilla alba and Oenanthe oenanthe, Phylloscopus trochilus and Anthus trivialis, Phylloscopus trochilus and Fringilla montifringilla, respectively.Pair density, number of species, biomass of adult birds and species diversity increased in the course of succession, none of these, however, monotonously. Average bird weight showed a decreasing trend although the variation was considerable. The degree of specialization in communities (measured by ratios derived from numbers of species, genera and families) increased in the course of succession with the exception that the initial stage had relatively high values. Species nesting and feeding in trees and shrubs increased in numbers during forest regeneration whereas species nesting and feeding on the ground showed the opposite trend. The proportions of hole‐nesting and sedentary species increased with increasing forest age.The initial stages of forest succession in the north are occupied by specialized open habitat species breeding originally on open bogs and shores. These communities thus clearly differ from those predicted from the general theory of succession, which postulates that the pioneer stages of succession are dominated by habitat generalists and that these communities should have relatively low values of community diversity.
Distribution, activity, life‐history and standing crop of Julidae (Diplopoda, Myriapoda) in the Central High Alps (Tyrol, Austria)*
Authors: Meyer Erwin 
Published: July 2006

The research area includes subalpine meadows, alder communities, dwarf‐shrub heaths, lichen heaths and highalpine meadows (1960 m–3090 m a.s.l.). The material consists of 4419 Julidae (31.6% adult) collected by extraction of litter samples (66.4%), in pitfall traps (26.3%) and by handsampling (7.3%). Cylindroiulus meinerti (Verhoeff) only occurred below 2000 m; Leptoiulus saltuvagus (Verhoeff) was mainly found at Alnus viridis sites; Leptoiulus simplex (Verhoeff) had its main distribution in the lichen heath (2200‐2300 m); Ommatoiulus sabulosus (L.) was found most frequently in the subalpine meadow and Leptoiulus alemannicus (Verhoeff) occurred up to 2800 m without any altitudinal concentration.Adults of L. saltuvagus showed only one distinct activity peak in September, those of L. simplex were diplochronous (June/September) and O. sabulosus summer stenochronous (July). L. saltuvagus reached maturity in stage IX (only males), X or XI after four or five Years. In their first year of growth the members of a generation reached the third or fourth stage, in the second year the sixth or seventh, in the third year the eighth or ninth. Females could carry full‐sized eggs in the autumn of the fourth year in the tenth stage or in the fifth year in stage eleven. Apparently eggs may be laid in spring of the fifth or sixth year. Overwintering density of L saltuvagus in alder litter was found to be 215.6 ± 38.7 inds m−2, the mean biomass 1.16 g m−2(max. 1.88 g m−2). Mean annual production during the growth period of 4‐5 months was in the order of 0.85 g m−2 (max. 1.36 g m−2).
Structure and succession of ant assemblages in a north European sand dune area
Authors: Gallé L. 
Published: July 2006

Ant assemblages of a successional dune area (Tvärminne, south Finland) were analysed at three levels: the distribution of species among habitats, the distribution of colonies within habitats and the spatio‐temporal distribution of individuals. The distribution of ant species among habitat patches representing different stages of succession is correlated with the composition of the epigeic fauna, the number and condition of dead twigs on the ground and the vegetation architecture. The composition of ant assemblages seems relatively independent of the plant species composition, and there are uncoordinated successional steps between the vegetation and ant communities.In the early successional stages interference competition is weak and insignificant, as indicated by the random spatial arrangement of colonies, the absence of postcompetitive niche segregation and the low encounter rates of ant workers on the ground and at baits. In the aggressive behavioural hierarchy, Formica cinerea is a submissive species as compared with either Formica sanguinea or Lasius alienus.
Element concentrations in mosses and surface waters of western Canadian mires relative to precipitation chemistry and hydrology
Authors: Maimer Nils , Horton Diana G. , Vitt Dale H. 
Published: July 2006

Concentrations of N, P, S, Na, K, Mg, Ca, Mn, Fe, Cu, Cd, Zn, Pb, Al, and AIA (acid insoluble ash) m mosses (three Sphagnum species and Tomenthypnum nitens, all hummock species) from a variety of mires, both ombrotrophic and minerotrophic, in the coastal western and central parts of Canada are considered in relation to surface water pH and concentrations of Na+, K+, Mg2+, Ca2+, Cl−, and SO42‐ Distinct west‐east concentration gradients were present for most elements in both mosses and water, but there were correlations between surface water and moss concentrations only for Ca and MgOn ombrotrophic sites and sites characterized by poor fen vegetation, wet deposition is the main source of elements in the surface water On rich fen sites, additional Ca and Mg from surrounding soils change the elemental proportions We conclude that hydrochemically the limit between poor and rich fen sites is more decisive than between bog and fen The increase in Ca may give brown mosses a competitive advantage over SphagnumMoss concentrations of Na and Mg are the only ones decreasing inland The constancy or inland increase of moss elemental concentrations may depend on either an increasing atmospheric supply (e g Pb), differences in moss growth rates (especially N, P, and K) or site conditions related to the water regime (e g Fe and Al)
Population fluctuations and habitat selection in the Eurasian red squirrel Sciurus vulgaris
Authors: Andrén Henrik , Lemnell Per‐Arne 
Published: July 2006

The population fluctuations of Eurasian red squirrel Sciurus vulgaris during ten winters showed a strong relation to Norway spruce Picea abres cone crop one year before Neither, Scots pme Pinus sylvestris cone crop nor mean temperature in December and January had an additional significant effect on the fluctuations The one‐year time‐lag between the good spruce cone crop and mcreased red squirrel density suggests that the rich food supply first mcrease the winter survival and then the reproductive successThe highest density‐index of red squirrels was found m old forest dominated by Norway spruce (mean density‐index 34 km−2) This habitat was also occupied in all 10 winters Other habitats with lower densities were occupied in fewer winters The vanation in density‐index was also highest in this habitat indicating that the dispersion of red squirrel individuals in different habitats follow the food supply
Germination ecology of the polycarpic grassland perennials Primula veris and Trollius europaeus
Authors: Milberg Per 
Published: July 2006

The seed germination behaviour of Primula veris and Trollius europaeus, both perennial, polycarpic grassland plants was compared The species have similar‐sized seeds that are dormant at dispersal Seeds buried in soil and exhumed at regular intervals showed that for both species, primary seed dormancy was overcome by cold‐stratification Hence, their germination in the field should occur in spring, following dispersal, or later Seeds of P veris became dormant again in the late spring/early summer, and dormancy was broken again in the second winter Seeds of T europaeus did not exhibit such changes in dormancySeeds of P veris did not germinate in darkness This suggests that P veris can accumulate a persistent seed bank because buried seeds are prevented from germinating Trollius europaeus, on the other hand, germinated equally well in darkness and in light which suggests that seeds might germinate even when they are too deep in the soil for seedlings to emerge Two lines of evidence confirm this difference in seed bank behaviour (1) Primula veris was detected in the persistent seed bank of a grassland site, whereas T europaeus was not (n) After 16 months burial, 85% of the P veris seeds but only 8% of the T europaeus seeds remained viable
Dynamics of the inflammatory reaction
Authors: Schultz‐Haudt Stig D. , Sölna Josrein 
Published: July 2006

Regardless of the type of tissue injury, the resulting inflammatory reaction usually follows a regular pattern composed of two distinct phases. The first phase, which occurs immediately upon injury, involves a temporarily increased permeability of the small vessels, mainly the venules. of the afflicted area. This rapidly wanes, whereafter the second phase of the reaction ensues. This comprises a prolonged increase of capillary permeability along with a progressive emigration of leucocytes for quit some hours. The further course of the reaction is determined by the type of the injurious agent as well as by the general status of health of the tissues and their previous experience with the injurious agent in question.It is generally agreed that the inflammatory reaction is induced and mediated by a number of biologically active substances, called mediators, which become activated or released upon tissue injury. It appears that the liberation of histamine is essential for the first phase of inflammation to take place. The course of the second phase is determined by several mediators, since there is accumulating evidence to the effect that increased capillary permeability and emigration of leucocytes are, at least in part, due to different types of mediator substances.The available evidence suggests that increased proteolytic activity is intimately involved with the progress of the inflammory reaction and is essential for wound healing.
The oxytalan connective tissue fibres in gingival hyperplasia in patients treated with sodium diphenyl‐hydantoin
Authors: Baratieri Antonio 
Published: July 2006

Oxytalan fibres in hyperplastic gingival papillae from 12 young epileptics who had been treated with sodium diphenyl‐hydantoin were studied with modifications of Fullmer and Lillie's (1958) and Löe and Nuki's (1964) staining methods. These fibres were compared with the fibres in clinically normal gin‐givac and in tissue from fibrous epulides.Fibres reacting with peracetic acid‐aldehyde fuchsin (i.e. oxytalan fibres) were present throughout the connective tissue and were especially numerous near the surface epithelium and in areas of inflammatory infiltration. The oxytalan fibres were especially prominent along the junction with epithelium, between the rete pegs and in the deeper connective tissue near bone where they tended to be arranged in large parallel bundles. In cases of fibrous epulis, however, there were very few oxytalan fibres in the connective tissue adjacent to the surface epithelium.It is concluded that the connective tissue performs an important supportive function to the epithelium in gingival hyperplasia, and is of special importance in the genesis of gingival hyperplasia in patients under treatment with sodium diphenyl‐hydantoin.
Influence of horinonal contraceptives on the gingiva of women
Authors: Lindhe Jan , Bjorn Anna‐Lisa 
Published: July 2006

Gestagen hormones commonly used as contraceptive in women, induce a hormonal situation which to some extent simulates pregnancy. The aim of the present investigation was to study the gingival conditions of women before and during 12 months of regular ose of contraceptive preparations. Two kinds of contraceptives were used: Delpregnin® and Gestadydral®. The mesial aspects of the gingiva of 5 maxillary incisors and canines were studied before beginning the experiment and after 2, 6, and 12 montks of hormone therapy. Jntracrevicolar sampling of gingival exudate was performed a.m. Brill (1959).Both the Delpregnin‐group and the Gestadydral‐groiip showed an increase in amount of exudate during the 12 months. At the use of Delpregnin there was a gradual increase in exudation during tke first six months of hormone therapy. In the group using Gestadydral, no increase in amount of exudate could be noted during the first six months, whereas a significant increase of the gingival exudate occurred between the last two examinations.The findings are discussed in view of current knowledge of gestagene hormone action on vascular permeability.
The effect of supervised oral hygiene on the gingiva of children. The effect of sodium fluoride
Authors: Koch Göran , Lindhe Jan 
Published: July 2006

The effect of sodium fluoride on the gingiva of children was investigated by regularly applying sodium fluoride to the teeth and gingiva for three years in two different ways:1. In a dentifrice slurry during daily supervised toothbrushing. The concentration of sodium fluoride was approximately 0.05 %.II. As a mouth rinse with 10 ml of an 0.5 % aqueous solution of sodium fluoride once every second week.The study included two control groups. The first, supervised by a dental nurse, brushed their teeth daily, using a dentifrice free from the fluoride component. The second rinsed their mouths once every second week with distilled water.The total number of children was 471 : 236 in the experimental groups and 235 in the control groups. At the time of the clinical examination, all were 12 14 years of age.The gingival state and the oral hygiene were recorded with the indices proposed by Löe and Silness (1963). and Silness and Löe (1964).The investigation revealed that:Sodium fluoride applied by means of a dentifrice slurry did not affect the gingiva.Sodium fluoride in the concentration of 0.5 % in a mouth rinse proved detrimental to the gingiva.The GI of the “fluoride rinsing group” was 0.75, whereas that of the “distilled water rinsing group” was 0.61.These results are discussed in the light of current knowledge of the effect of fluorine in dental plaques and connective tissues.
A reproducible method of evaluating oral hygiene
Authors: Pilot T. 
Published: July 2006

A reproducible method of evaluating oral hygiene has been developed for use in blind studies. An erythrosin‐containing disclosing solution is applied and black and white photographs taken of the 12 anterior teeth.The method was evaluated by one investigator on a group of 35 experimental subjects. The reproducibility of the results were estimated by scoring from the same photographs after intervals of one month and ten months. In addition, reproducibility was tested by re‐photographing the anterior teeth of the same subjects with variations in the position of the camera. Variations of up to 15 degrees in the vertical and horizontal planes were tested.It was found that errors with this method were small and that it is sufficiently accurate for controlled studies. Also it has shown that focusing with a hand‐held camera, without special equipment to fix the patient/camera relationship, is satisfactory.
Human gingival mast cells
Authors: Shelton L. E. , Hall W. B. 
Published: July 2006

The literature concerning changes in mast cell populations in human gingiva associated with inflammation is contradictory. No reports of the effects of therapy on these populations have been published.This study was designed to determine whether gingival mast cell populations are altered by inflammation and whether these populations change following routine therapy. Twenty systemically healthy patients, age 20 to 40, ten with normal gingiva and ten with periodontitis of similar severity bilaterally, were selected for study. Biopsies of interdental papillae from premolar regions were utilized. In the periodontitis group, one papilla was obtained prior to therapy, the second from the ipsilateral quadrant two weeks after root planing and curettage.Mast cell populations were determined from frozen sections stained with EACNAS‐GBC Hematoxylin (Hall, 1966). Granule estimates were obtained from photographic negatives of frozen sections stained with EACNAS‐GBC alone, using a photoelectric assaying device. Mast cell counts and granule estimates were made separately for beneath col and beneath keratinized tissue. Results show a larger mast cell population and a greater granule estimate under keratinized tissue than beneath the col. Mast cell counts and granule estimates show a decrease during periodontitis and a return to “normal” limits following routine therapy. These results support the concept that mast cell numbers are decreased in the presence of chronic inflammation but return to “normal” levels following resolution of the inflammatory process.
Influence of sex hormones on gingival exudation in gingivitis‐free female dogs
Authors: Lindhe Jan , Attström Rolf , Björn Anna‐Lisa 
Published: July 2006

This investigation was undertaken to study the influence of an increased level of estrogen and progesterone upon gingival exudation in gingivitis‐free female dogs. Four female dogs constituted the experimental material. For three weeks prior to the hormone study all were supplied with a hard diet consisting of raw bovine tracheas. In addition, the teeth were cleaned every second day with rubber cups and pumice. During the experimental period gingival fluid was collected from the buccal areas.The intra‐crevicular method was applied in three quadrants and the extra‐crevicular in one quadrant. A total of seven strips from six teeth were measured in each quadrant. Gingival fluid was sampled five times during the course of this study; once immediately before and once seven days after each of the two hormone periods and twice during the course of hormone administration. During the first hormone period comprising 52 hours, each dog was twice given 1 mg estrogen and 25 mg progesterone. During the second hormone period, which also lasted for 52 hours, the dose of each hormone was doubled. The hormones were injected intramuscularly in the hind leg. The results show that when the intra‐crevicular technique of sampling was used, the administration of estrogen and progesterone induced an increased flow of gingival fluid. The increased gingival exudation was observed in all four dogs and occurred in both of the hormone periods. At the end of the period of sex hormone administration the gingival exudation returned to normal. The present study also showed that no influence of sex hormones on gingival exudation could be demonstrated by the extra‐crevicular sampling method.
Influence of sex hormones on gingival exudation in dogs with chronic gingivitis
Authors: Lindhe Jan , Attström Rolf , Björn Anna‐Lisa 
Published: July 2006

The aim of the present investigation was to determine whether or not repeated administration of estrogen and progesterone induces an increased gingival exudation in dogs.Five female mongrel dogs constituted the experimental material. Six months prior to the start of the hormone experiments and during the experimental period the animals were given a soft gingivitisinducing diet. During the “hormone‐periods” each dog was given 1 mg estrogen every second day, and 25 mg progesterone every day. The hormones were injected intramuscularly in one of the dogs hind legs. The degree of gingival exudation was assessed by the method described by Brill (1959) and Egelberg (1964).The results of the investigation clearly show that, in dogs with a manifest chronic gingivitis, the administration of estrogen and progesterone causes a rise in the amount of exudate obtainable on filter paper strips inserted into the gingival crevice. The termination of the hormone supply resulted in a marked and rapid decrease in exudation. This increase and decrease of the amount of gingival fluid in relation to the increase and decrease of the estrogen and progesterone level indicate that these female sex hormones affect the permeability of the dento‐gingival vessels.
A method for evaluation of small sample, short duration experiments
Authors: Betz Peter K. , Ratcliff Perry A. , Levin Joel R. , Rothman Frederic L. 
Published: July 2006

The purpose of this study was to see if any statistically significant differences could be shown between groups when using small experimental samples in a short duration experiment.Because small samples were employed and because normality and equality of variance assumptions were doubtful, the «Kruskal‐Wallis» Nonparametric «One‐Way» Analysis of Variance by Ranks was performed on the data to test for statistical significance (Siegel 1956). The data suggest that, within the severe limits of this study, any of the alterations from normal caused changes in cementum.The effects of hypophysectomy, adrenocorticotropic hormone and somatotrophic hormone on the thickness of cementum of rat molar roots were investigated, using statistical methods which were able to show some between‐group differences when small samples were used in short experiments. Some of the anticipated changes in cementum with these hormones did not become apparent in the 32 rat molars during the 36 day experiment.