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1.
Warneckea populations from “sand-forest” or “sand-thicket” habitats in Tembe Elephant Park, South Africa, and Licuati Forest Reserve in adjacent southern Mozambique were previously thought to be a small-leaved form of W. sousae, which typically includes larger-leaved plants ranging from central Mozambique northward to Tanzania. We examine this hypothesis using molecular and morphological evidence. Maximum-likelihood phylogenetic analysis of combined nrDNA ETS and ITS sequence data failed to resolve W. sousae and the Maputaland populations as an exclusively monophyletic group. Instead, the Kenyan endemic W. mouririifolia was strongly supported as the sister species of W. sousae, and the Maputaland plants were resolved in a separate, strongly supported clade together with populations of an as-yet undetermined Warneckea species from northern Mozambique. A hypothesis of exclusive monophyly for the plants from Tembe and Licuati had moderate support in separate ETS and ITS1 analyses (bootstrap proportions of 88% and 81%, respectively). Statistically significant differences in leaf dimensions and internode length were found between the Maputaland plants and typical W. sousae. We conclude that the populations from Tembe and Licuati represent a distinct species, which we describe as W. parvifolia. The species differs from W. sousae in having shorter internodes (mostly 5–25 mm not 10–60 mm long), smaller leaves (mostly 14–32 × 8–19 mm not 40–76 × 22–52 mm), shorter petioles (mostly 1–1.5 mm not 1.5–6 mm long), smaller flowers (hypanthium 1 × 1.5–1.75 mm not 1.5–2 × 2 mm; calyx lobes 0.5 mm not 0.75 mm long; staminal filaments 3–4 mm not 5 mm long; style 4–5 mm not 9 mm long), and globose fruit (not obovoid). An IUCN conservation status of Endangered (EN) B1a, b(ii, iii) is indicated for W. parvifolia, due to its limited distribution and projected declines in its habitat quality and area of occupancy.  相似文献   

2.
《Small Ruminant Research》2007,72(1-3):194-199
The morphometrics of mandible and teeth of mixed-breed goats on rangeland were analyzed to investigate the association between the oral apparatus and diet type. Canonical relationship between sets of mandible measurements (7) and main plants ingested (17) indicated that, overall, oral characteristics tended to modify ingestive behavior (canonical correlation = 0.81). In general, incisor length had a greater effect (absolute value of standardized coefficient: AVSC = 0.56) on ingestion of Nolina cespitifera than did other mandible variables. Incisor width influenced the ingestion of Parthenium incanum (AVSC = 0.47) and Flourensia cernua (AVSC = 0.43). Distance between the bases of the last most lateral incisors (I4 or corners) was associated with the ingestion of Atriplex canescens (AVSC = 0.54) and Florensia cernua (AVSC = 0.69). Incisor breath was important for the consumption of Larrea tridentata (AVSC = 0.68) and Cowania plicata (AVSC = 0.50). The ingestion of Agave lechuguilla (AVSC = 0.51) and Sphaeralcea angustifolia (AVSC = 0.43) were influenced principally by muzzle width. Distance between first molars was the variable most closely associated to the ingestion of Buchloe dactyloides (AVSC = 0.51) and Croton dioicus (AVSC = 0.62). Mandible length had a greater effect on the ingestion of F. cernua and Atriplex canescens than did other oral traits. Variation in the oral apparatus did not affect percentage of grasses, forbs and shrubs of goat diets. Fecal nitrogen, fecal phosphorous and number of species consumed were not related to oral traits. These results suggest that different dimensions in the oral apparatus of grazing goats lead to divergent selection of range plants, without altering the quality of their diet.  相似文献   

3.
Chrysoperla agilis Henry et al. is one of the five cryptic species of the carnea group found in Europe. Identification of these species is mainly based on the distinct mating signals produced by both females and males prior to copulation, although there are also morphological traits that can be used to distinguish among different cryptic species. Ecological and physiological cryptic species-specific differences may affect their potential as important biological agents in certain agroecosystems. To understand the effects of temperature on the life-history traits of C. agilis preimaginal development, adult longevity and reproduction were studied at seven temperatures. Temperature affected the development, survival and reproduction of C. agilis. Developmental time ranged from approximately 62 days at 15 °C to 15 days at 30 °C. Survival percentages ranged from 42% at 15 °C to 76% at 27 °C. One linear and five nonlinear models (Briere I, II, Logan 6, Lactin and Taylor) used to model preimaginal development were tested to describe the relationship between temperature and developmental rate. Logan 6 model fitted the data of egg to adult development best according to the criteria adopted for the model evaluation. The predicted lower developmental threshold temperatures were 11.4 °C and 11.8 °C (linear model), whereas the predicted upper threshold temperatures (Logan 6 model) were 36.6 and 36.9 °C for females and males, respectively. Adult life span, preoviposition period and lifetime cumulative oviposition were significantly affected by temperature. The effect of rearing temperature on the demographic parameters is well summarized with the estimated values of the intrinsic rate of increase (rm) which ranged from 0.0269 at 15 °C to 0.0890 at 32 °C and the highest value recorded at 27 °C (0.1530). These results could be useful in mass rearing C. agilis and predicting its population dynamics in the field.  相似文献   

4.
ObjectiveTo study a possible influence of betel chewing on the composition of the oral microflora in plaque and saliva and on oral health parameters as well as a possible betel effect on oral bacteria in vitro.Material and methodsThirty-two adults (16 betel chewers and 16 non-betel-chewing controls) of the Karen Hill tribe in Thailand were investigated. Saliva samples and 2 pooled supragingival plaque samples were taken from each individual for microbial analysis with culture and 4 subgingival samples for analysis with the DNA–DNA hybridization method against 12 periodontitis associated bacterial species. Caries (DMFS), plaque (PlI%) and bleeding on probing (% BoP) was registered as well as number of sites with >5 mm probing pocket depth (PPD). Water extract of the betel (areca chatechu) nut was tested for its antimicrobial effect in vitro against 10 oral bacterial species with the agar diffusion method.ResultsAn antimicrobial effect of betel nut water extract was found on the oral microorganisms in vitro. The levels of mutans streptococci and lactobacilli in saliva were low or absent in both chewers and controls. The prevalence of the periodontitis associated bacteria was >90%. Betel chewers had significantly lower levels of some bacteria in subgingival plaque (Prevotella intermedia p < 0.001) than non-chewers. This study population was low in missing teeth (mean 0.7 and 0.3), caries decay (DS 2.1 vs 1.6), and number of deep pockets (mean 1.9 vs 1.3). Great variation in oral hygiene (PlI and BoP) between the subjects was seen.ConclusionsAn antimicrobial effect of the betel nut was found in vitro and with a possible effect also in vivo however it did not seem to influence clinical parameters such as plaque index, caries prevalence (DMFS), bleeding on probing and number of deep pockets.  相似文献   

5.
《Small Ruminant Research》2010,91(1-3):114-119
Grazing livestock frequently ingest toxic plants, occasionally with fatal results. Behavioral adjustments by livestock may reduce toxin intake; for example they can develop food aversions which may protect animals from over-ingestion of toxic plants. The purpose of this study was to evaluate three plants with different mechanisms of toxicity for their efficacy in conditioning a taste aversion: (1) a seleniferous plant, Xylorhiza glabriuscula, (2) an indolizidine alkaloid-containing plant, Astragalus lentiginosus, and (3) a diterpene acid-containing plant, Gutierrezia sarothrae. For each plant species, 15 sheep were divided into 3 treatment groups and periodically tested for consumption of a novel food, whole corn: (1) controls – given 200 g of ground alfalfa hay by oral gavage, (2) averted – given lithium chloride (LiCl) at 175 mg/kg BW via oral gavage, and (3) given the specific target plant by oral gavage. X. glabriuscula was given at a dose equivalent to 3 mg Se/kg BW; A. lentiginosus was given at a dose equivalent to 3 mg/kg of the toxic alkaloid, swainsonine; freshly thawed G. sarothrae was dosed at 5 g/kg body weight (BW). Both LiCl and Xylorhiza conditioned an aversion to corn, with sheep eating 1.6 and 0.6% of offered corn during the final test; controls were not averted, eating 93% of the corn (P < 0.01). Sheep were partially averted by Xylorhiza after a single dose, and the aversion was complete after the second dose. Sheep were not averted by A. lentiginosus or G. sarothrae. Of the three toxic plants used in this study, only Xylorhiza conditioned a taste aversion. These results likely reflect differing mechanisms of action of the plant toxin(s) on brain and gut structures important for forming conditioned taste aversions. These results suggest that conditioned aversions to Se-containing plants may help to deter consumption of such plants by grazing ruminants on rangelands.  相似文献   

6.
Frugivorous animals play a major role in dispersing tropical, and to a lesser extent, temperate tree species. In order to attract potential seed dispersers, plants generally offer a reward of fleshy fruit pulp. Criteria for fruit choice by avian frugivores are influenced by a number of non-nutritive (e.g. fruit size and colour) factors; and nutritional composition of the fruit. There is a paucity of nutritional composition and other fruit trait data of indigenous South African fruit. This information is necessary in order to determine which frugivores are likely to ingest which fruits and consequently act as potential seed dispersal agents. This information would provide us with an understanding of the inter-relationships between indigenous fruit and frugivores in South Africa. Consequently nutritional composition was investigated in various indigenous fruit species that avian frugivores feed on. Fruits were collected from 38 indigenous tree species found in KwaZulu-Natal Afromontane and coastal forests. Pulp was freeze-dried to constant mass and then analysed for sugar, lipid and protein content; and for water content determination. Fruit width in this study ranged from 4 mm (Searsia rehmanniana and Trema orientalis) to 40 mm (Annona senegalensis, Ficus sur and Xylotheca kraussiana). Of the fruits examined in this study 29% were black and 43% were red when ripe. Most (84%) fruit species analysed for sugar content were hexose dominant with 50% being fructose and 34% being glucose dominant. Only 16% of the fruit species analysed were sucrose dominant. Fruits in this study were generally observed to be high (mean: 68.1 ± 3.3%; n = 30) in water content; and low in protein and lipid content respectively (mean: 8.2 ± 0.5%; 9.3 ± 2.2%; n = 30) indicating that these fruit species could be considered as nutrient-dilute. Future studies need to determine the nutritional composition of the remaining indigenous South African fruit in order to develop a comprehensive database as well as examining non-nutritive factors.  相似文献   

7.
The importance of the spatial organisation of individuals in explaining species coexistence within a community is widely recognised. However, few analyses of spatial structure have been performed on tropical agroforests.The main objective of this study was to highlight the links between spatial organisation of shade trees on the one hand, and shade tree species richness and cacao yield on the other, using data from 29 cacao agroforests in Costa Rica.A method of spatial statistics, Ripley's K-function, was used to analyse the spatial organisation of shade and cacao trees in the study plots. For each stand, the X and Y coordinates of ≥2.5-m-tall trees were recorded. In each plot we also assessed shade tree species richness and cacao yield (with total number of pods = number of pods damaged by frosty pod rot + number of healthy pods).Three types of stands were identified: the first was characterised by significant clustering of shade trees, the highest shade tree species richness (S = 6), and the highest number of damaged pods (139 pods ha?1 year?1). The second type was characterised by random spatial organisation of shade trees. The third type showed a trend towards regular organisation. Species richness of shade trees did not differ significantly between the last two types (S = 4 for both), nor did the number of damaged pods (56 pods ha?1 year?1 and 67 pods ha?1 year?1 respectively).Although the trends were not statistically significant for all the variables in our data set, the clustered spatial structure appears to favour a synergy between environmental (tree species richness), and provisioning (cacao production) services.  相似文献   

8.
EPA, DHA, cholesterol and phospholipid content were determined in the Trachinus draco, Trigla lyra and (wild and cultured) Pagrus pagrus muscles.The EPA and DHA levels – as determined by GC-GC/MS – in the cultured P. pagrus muscles (233.20 ± 16.3 and 399.39 ± 31.1 mg/100 g of the wet tissue respectively) were found to be significantly higher compared to the ones in the wild P. pagrus, T. draco and T. lyra (26.31 ± 2.26, 158.24 ± 10.92 mg/100 g, 28.65 ± 1.68, 155.97 ± 2.63 mg/100 g 35.66 ± 0.66 and 102.52 ± 1.71 mg/100 g of the wet muscles respectively). The amounts of cholesterol (determined by GC on a capillary column) and phospholipids in the cultured P. pagrus muscles were significantly higher (149.3 mg/100 g and 0.80 g/100 g of the wet tissue respectively) compared to the ones in the wild P. pagrus (8.73 mg/100 g and 0.40 g/100 g), T. draco (41.72 mg/100 g and 0.59 g/100 g) and T. lyra muscles (38.63 mg/100 g and 0.40 g/100 g of the wet tissue respectively).The highest DHA/EPA and ω-3/ω-6 ratios were 6.00 and 5.93 in wild P. pagrus and T. draco muscles respectively, while the lowest in cultured P. pagrus (1.71 and 1.48 respectively).  相似文献   

9.
The essential oil of Ajuga pseudoiva, collected from Tunisia, was analyzed using gas chromatography–mass spectroscopy. Thirty-two compounds accounting for 95.76% of the total oil were identified. Sesquiterpenes were found to be the most abundant components of A. pseudoiva oil. And they were mainly represented by viridiflorol (30.17%), germacrene B (9.26%) (α, β and γ)-eudesmol (8.11%) and aromadendrene (7.45%). The essential oil of A. pseudoiva showed radical scavengers activity (IC50 = 0.72 mg/mL) and displayed lipid peroxidation inhibitory activity (IC50 = 0.6 mg/mL). A. pseudoiva essential oil was also found to exhibit a dose-dependent ACE inhibitory activity with an IC50 value of 65.5 μg/mL. Moreover, the antimicrobial activity of the essential oil was tested against 17 species of microorganisms, and the results obtained showed significant antibacterial activity against the Gram-positive and Gram-negative bacteria, with inhibition zones and minimal inhibitory concentration values of 14–32 mm and 84–137 μg/mL and 6–21 mm and 105–336 μg/mL, respectively. Higher activity was also found against several fungal strains.  相似文献   

10.
Dysosma versipellis (Berberidaceae) is an endangered and endemic species in China. To provide scientific foundation for formulating conservation strategies, we sampled six extant populations of this species and assessed the levels and patterns of genetic diversity using ISSR markers (11 primers). Of 144 bands detected 57.64% were polymorphic, but on average only 20.72% were polymorphic within populations. Our results revealed a low level of intraspecific genetic diversity (at population level: Hpop = 0.082, HB = 0.177, SI = 0.1194; at species level: Hpop = 0.207, HB = 0.378, SI = 0.3069). A high level of genetic differentiations among populations was detected based on Nei's genetic diversity analysis (60%), AMOVA analysis (65%), and Bayesian analysis (53%). The low levels of heterozygosity and high genetic differentiation observed in D. versipellis may be the consequence of low rate of natural recruitment, clonal growth, gene drift, and habitat fragmentation. Based on this, we suggest that in situ conservation be an important and practical measure for maintaining the genetic diversity of this species. Ex situ conservation should sample from different populations across the distribution range of the species to conserve high genetic diversity.  相似文献   

11.
Species composition and distribution of ciliates were investigated in the rumen contents of 25 domestic cattle (Bos taurus taurus L.) living in Kastamonu, Turkey. Forty-seven species and 37 morphotypes representing 15 genera were identified. Of them, a new species of Ostracodinium was recognized and described as Ostracodinium anatolicum n. sp. This new species has two caudal lobes. The dorsal lobe is small and rounded and the ventral lobe is triangular shaped and bent toward the dorsal side like a thick hook. Furthermore, the anterior end of the macronucleus (1/5 of the length) is bent toward the left like a hook. The density of rumen ciliates in cattle was 96.8 ± 43.3 × 104 cells mL−1 and the mean number of ciliate species per host was 14.2 ± 4.4. Entodinium longinucleatum, E. nanellum, E. simulans and Isotricha prostoma were the most abundant species, each with a prevalence of 88%. Entodinium chatterjeei, E. bifidum m. monospinosum, Hsiungia triciliata, Oligoisotricha bubali, Ostracodinium dogieli, O. mammosum and O. munham are new host records for cattle from Turkey.  相似文献   

12.
《Small Ruminant Research》2010,94(2-3):180-185
The aim of this study was to determine if the presence or absence of a corpus luteum (CL) during estrous synchronization in ewes can affect the ovarian follicular population and the serum oestradiol concentrations. The estrous cycles of 197 Sanjabi ewes were synchronized using a 12-day treatment with intravaginal progestagen sponges (Chronogest®). Estrus was detected in 144 ewes, 27–39 h after sponge removal. Blood samples were taken daily from day 2 and continued for 19 days and analyzed for serum oestradiol concentration. Nine ewes were slaughtered on each experimental day (days 1–16 after estrus) for ovary collection. The ovaries per ewe were classified as those without, or with one or two CL's, for each slaughter day. Visible follicles on the surface of the ovaries were classified, based on their diameter, into (i) very small (<2 mm), (ii) small (2–3.4 mm), (iii) medium (3.5–5 mm) and (iv) large (>5 mm) categories, and the respective numbers recorded. Results indicated, the number of ovarian follicles to decrease (P < 0.01) from days 1 to 5 of the cycle and showed a significant increase on day 7. Numbers were high again on day 11 and decreased (P < 0.01) on day 16 of the estrous cycle. The serum oestradiol concentrations were significantly higher (P < 0.001) in the double than in the single ovulating animals (one or two CL's, respectively) on days 2–0. However serum levels were also significantly higher (P < 0.001) in single, than twin ovulating animals on days 4–5 and 12–16 of the estrous cycle. There were no significant differences in the total number of very small follicles between animals without and those with two CL's. The number of small, medium and large follicles in ewes, with or without a CL on the ovary was significantly higher (P < 0.01) than ewes with two ovulations at certain stages of the estrous cycle. The present study provides evidence of differences in the follicular ovarian population in ovaries without CL's and double ovulations. The existence of an intraovarian effect of the CL numbers on follicular population is demonstrated.  相似文献   

13.
《Aquatic Botany》2007,86(1):30-36
Shoots of the Mediterranean seagrass Posidonia oceanica (L.) Delile can be overgrown with a thick encrustation of the bryozoan Calpensia nobilis (Esper) (Chelostomida) particularly under high hydrodynamic conditions. We compared shoots with and without this encrustation and assessed whether it affected shoot morphology and production, and incidence of polychaete borers. The borers collected were represented by three species of polychaete Eunicidae (Lysidice ninetta, Lysidice collaris and Nematonereis unicornis). Shoots affected by overgrowth of C. nobilis showed a significantly lower borer frequency (17% versus 49%), lower values of both yearly biomass of the rhizome (mean 6.3 mg/year in shoot with C. nobilis versus 8.3 mg/year in shoot without) and biomass/elongation (B/E) ratio, and lower mean sheath thickness (0.25 mm versus 0.30 mm), while the mean width of the leaves was slightly higher (1.0 mm versus 0.7 mm). Significant Spearman coefficient's values were estimated between carbonate mass of C. nobilis and rhizome length, muff length and rhizome length, and maximum thickness of the muff and rhizome length. Plant and bryozoan morphometrics allowed to estimate between 5 and 10 years the colonization age of C. nobilis on the living shoots studied.  相似文献   

14.
The influence of temperature on the diurnal activity of five species of aphidophagous lady beetles (Coleoptera: Coccinellidae) was investigated between 0700 and 1900 h in chili (Capsicum annuum L.) agroecosystems and neighboring vegetation (goose grass, Eleusine indica L.). The lady beetle species observed were Menochilus sexmaculatus Fabricius, Coelophora inaequalis F., Coccinella transversalis F., Harmonia octomaculata F. and Coelophora bissellata Mulsant. More lady beetles (of all species) were found during cooler periods (at 0700, 0900, 1100, and 1900 h). The diurnal pattern of lady beetle adult was temperature dependent. On chili plants, numbers were higher at temperatures between 22 to 30 °C (at 0700, 0900, 1100 and 1900 h) and numbers decreased when temperatures were above 30 °C. When temperature was above 30 °C under the chili plant canopy, numbers were higher in neighboring goose grass, where temperatures were cooler (< 30 °C). Numbers of all species were negative correlated between chili plant and goose grass.  相似文献   

15.
The present study describes the distribution of taste buds and teeth in the oropharyngeal cavity of 13 species of adult (18–60 mm SL) Starksiini fishes inhabiting subtidal waters of the Neotropical region. Four types of taste buds described previously in other fish groups were observed within the oropharyngeal cavity, of which type I, situated on prominent protruding papillae, is the most common. The number of taste buds in this cavity varies considerably, ranging from ca. 202 in Starksia lepicoelia to ca. 770 in S. sluiteri. In all the studied species, taste buds are more numerous on the posterior (160–396) than on the anterior (42–294) part of the oropharyngeal cavity. The presence of different numbers of taste buds in different Starksiini species of the same standard length suggests that numbers of taste buds are not directly correlated with size and may be species‐specific. Teeth are found on the premaxilla, dentary, vomer, palatine (in some species) and the upper and lower pharyngeal jaws (third pharyngobranchials and fifth ceratobranchials, respectively); the form and number of teeth and taste buds on each of these sites differs among the various species of Starksiini and between them and closely related species of the labrisomid tribes Labrisomini, Mnierpini, and Paraclinini. The results thus suggest potential systematic value in certain features of the oropharyngeal cavity for blenniiform fishes. It is also shown that benthic‐feeding omnivorous fishes have higher densities of taste buds than piscivorous fishes. A possible correlation among numbers of taste buds, their positions in the oropharyngeal cavity, and other parameters is discussed. J. Morphol., 2012. © 2012 Wiley Periodicals, Inc.  相似文献   

16.
Henneguya jocu n. sp. (Myxosporea, Myxobolidae) is described from the gill lamellae of the marine teleost fish Lutjanus jocu, with a focus on ultrastructural and molecular features. This myxosporean forms subspherical cysts up to ∼260 μm × 130 μm long, and develops asynchronously. Mature myxospores ellipsoidal with a bifurcated caudal process. Myxospore length 10.9 ± 0.4 μm (n = 50); width, 8.2 ± 0.3 μm (n = 50); and thickness, 2.9 ± 0.5 μm (n = 50). Two equal caudal processes, 34.1 ± 1.0 μm long (n = 50); and total myxospore length, 45.2 ± 1.0 μm (n = 50). Two symmetric valves surround two ellipsoidal polar capsules, 5.0 ± 0.3 × 1.4 ± 0.2 μm (n = 20), each containing an isofilar polar filament forming 4–5 coils along the inner wall of these structures, as well as a binucleated sporoplasm presenting a spherical vacuole and several globular sporoplasmosomes. Both the morphological data and molecular analysis of the SSU rDNA gene identify this parasite as a new species of the genus Henneguya. Maximum Likelihood and Maximum Parsimony analyses further indicate that the parasite clusters within others marine Myxobolidae species, forming a group alongside other Henneguya species described from marine hosts.  相似文献   

17.
An efficient and promising protocol for in vitro propagation of Zingiber officinale Rosco using sprouting buds was established. Sprouting buds were sterilized and cultured onto MS medium supplemented with different growth regulators. Augmentation of MS-medium with 4.5 mg/l BAP recorded the highest percentage of shootlets multiplication. Shootlets were highly rooted on half strength of B5 medium supplemented with 1.0 mg/l NAA. The maximum percentage of acclimatization, hardening and rhizomes production of in vitro derived plants in greenhouse was 80–100%.  相似文献   

18.
The carob moth, Ectomyelois ceratoniae (Lepidoptera: Pyralidae), is the most important pest of pomegranate orchards (in terms of economic damage) within Iran, and hence, several control procedures, including biological methods of control, have been attempted as a means of controlling populations of this insect. This research was carried out in order to study the biology of Apanteles myeloenta (Hymenoptera: Braconidae), a larval parasitoid of the carob moth. Laboratory studies were conducted to determine larval developmental time, adult longevity, sex ratio, parasite progeny production, and host stage preference of A. myeloenta. At 25 ± 1 °C, immature developmental time (egg to pupa; mean ± SE) was 28.33 ± 0.85 days and 27.46 ± 0.37 days for male and females, respectively. Adult females survived on average 17.5 ± 0.14, 11.7 ± 0.22, 3.4 ± 0.18, and 2.8 ± 0.12 days at 25 C when provided with honey and water, honey only, water only or no food source, respectively. The sex ratio (females to males) of A. myeloenta was 1:3.5 from hosts parasitized in the first instar, 1:3 for second instars and 1:2 for third instar carob moth larvae. Female A. myeloenta typically preferred to parasitize second instar over third or first instar. The oviposition activity peaked on the 7th and 8th days following emergence, when provided with honey, and 10% sucrose solution, respectively.  相似文献   

19.
ProjectTo measure the levels of heavy metals (Hg, Sn) in the dental pulp and blood samples of patients with long-term amalgam restorations.Procedure12 amalgam restored and 12 non-restored, sound teeth were chosen and access cavity preparation to the pulp chamber was made. The contents were transferred and dissolved in 5 mL of concentrated nitric acid followed by placement in an oven at 180 °C for tissue digestion. After cooling the tubes each digested sample was transferred to an atomic absorption system to measure the levels of heavy metals. The blood samples of five patients in each group were randomly analyzed to determine the levels of these heavy metals in the blood and if there were a correlation between these levels in blood and pulp. Data were analyzed by t-test at a P < 0.05 level of significance.ResultsNo significant difference was seen between the levels of Hg and Sn in pulp tissues (P > 0.05); however, the blood analysis showed higher level of Hg amalgam group (P = 0.009). The analysis between the pulp and blood samples showed positive correlations for both Hg and Sn elements in dental pulp and the blood (P = 1.000) (P = 0.900).ConclusionsThe long-term presence of dental amalgam (at least 5 years) did not result in any remarkable changes in the levels of mercury and tin in the pulp tissue; however, there were increases in the level of mercury in the blood circulation even five years following the placement of the restoration.  相似文献   

20.
Chrysoperla genanigra Freitas is a common green lacewing associated with melon pests in the Northeastern Brazil. All life stages of this recently described species were studied under a range of constant temperature conditions (17, 21, 25, 29, 33, 35 and 37 °C), a photoperiod of 12 h:12 h (L:D) and 70 ± 10% relative humidity. Adults of C. genanigra were fed on a diet consisting of a 1:1 (v/v) mixture of brewer’s yeast and honey, while larvae were provided with eggs of Sitotroga cerealella (Olivier) ad libitum. The duration of preimaginal development of the species was inversely proportional to temperature and ranged from approximately 63 days at 17 °C to 15 days at 35 °C. The percentage of adult emergence varied from 6.7% at 17 °C to 76.7% at 25 °C, although no larvae were able to complete development at 37 °C. The lower thermal threshold for total preimaginal development was approximately 10.8 °C and the thermal requirement was 336.7 degree-days. Egg production, along with the longevity of both males and females, were significantly affected by temperature. It is concluded that the best temperature for rearing C. genanigra is 25 °C, with the lowest preimaginal mortality and the highest egg production (992.7 eggs/female).  相似文献   

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