26 research outputs found
Determination of physiological responses on hyacinth (Hyacinthus orientalis) plant exposed to different salt concentrations
Plant growth is restricted by many environmental factors. Soil salinity is considered as an important agricultural problem for dry and semi-dry fields in many regions around the world. It is known that salinity is an important stress factor restricting water and nutrient intake of plants. In this study, the physiological responses of hyacinth (Hyacinthus orientalis) exposed to different salt concentrations (0, 50, 100, 200 and 400 mM) were investigated. The stomata status, osmotic potential, proline content, chlorophyll and caretonoid contents and protein variances were examined in the plants exposed to salt. The physiological responses of the hyacinth varied depending on the salt concentration. Stress was kept under control at concentrations of 50, 100 and 200 mM; however, bulbs were decayed and necrosis was formed on the leaves at concentration of 400 mM. This study on hyacinth will help us to learn about tolerance mechanisms raised by plants with bulb against salt stress. It was seen in this study that the stomata size decreased when the salt concentration was increased and the chlorophyll and caretonoid contents also decreased. A significant decrease was seen in proline content and it increased at 400 mM and some protein bands which existed in control group disappeared in electrophoresis study.Key words: Salt, stress, hyacinth
The effects of different warm stratification periods on the seed germination of some Rosa taxa
In this study, the effects of different warm stratification periods on the seed germination of some Rosa species such as Rosa heckellana ssp. vanheurckiana, Rosa canina, Rosa pulverelanta and Rosa dumalis naturally grown in the Van region were investigated. In 2007, seeds of these species were kept at 25°C warm stratification for 10, 11 and 12 weeks, and then transferred to 5°C for cold stratification till the initiation of germination. Germination response to treatments of R. heckellana ssp. vanheurckiana seeds was different compared to the other species. The seeds of R. heckellana ssp. vanheurckiana germinated in a short time (when they kept in warm stratification followed by cold stratification between 1 - 3 weeks). The seeds of the other species required 5 months of cold stratification after warm stratification to overcome seed dormancy. The overall germination percentage were 18.80% in R. canina, 13.80% in R. pulverelanta and 13.53% in R. dumalis at 25°C of warm stratification followed by 5°C cold stratification. We determined that for these three taxa, the most appropriate method of stratification was 11 week warm stratification followed by cold stratification
Limits on Dark Matter Effective Field Theory Parameters with CRESST-II
CRESST is a direct dark matter search experiment, aiming for an observation
of nuclear recoils induced by the interaction of dark matter particles with
cryogenic scintillating calcium tungstate crystals. Instead of confining
ourselves to standard spin-independent and spin-dependent searches, we
re-analyze data from CRESST-II using a more general effective field theory
(EFT) framework. On many of the EFT coupling constants, improved exclusion
limits in the low-mass region (< 3-4 GeV) are presented.Comment: 7 pages, 9 figure
First results from the CRESST-III low-mass dark matter program
The CRESST experiment is a direct dark matter search which aims to measure
interactions of potential dark matter particles in an earth-bound detector.
With the current stage, CRESST-III, we focus on a low energy threshold for
increased sensitivity towards light dark matter particles. In this manuscript
we describe the analysis of one detector operated in the first run of
CRESST-III (05/2016-02/2018) achieving a nuclear recoil threshold of 30.1eV.
This result was obtained with a 23.6g CaWO crystal operated as a cryogenic
scintillating calorimeter in the CRESST setup at the Laboratori Nazionali del
Gran Sasso (LNGS). Both the primary phonon/heat signal and the simultaneously
emitted scintillation light, which is absorbed in a separate
silicon-on-sapphire light absorber, are measured with highly sensitive
transition edge sensors operated at ~15mK. The unique combination of these
sensors with the light element oxygen present in our target yields sensitivity
to dark matter particle masses as low as 160MeV/c.Comment: 9 pages, 9 figure
A Low Nuclear Recoil Energy Threshold for Dark Matter Search with CRESST-III Detectors
The CRESST-III experiment (Cryogenic Rare Events Search with Superconducting Thermometers), located at the underground facility Laboratori Nazionali del Gran Sasso in Italy, uses scintillating CaWO₄ crystals as cryogenic calorimeters to search for direct dark matter interactions in detectors. A large part of the parameter space for spin-independent scattering off nuclei remains untested for dark matter particles with masses below a few GeV/c², despite many naturally motivated theoretical models for light dark matter particles. The CRESST-III detectors are designed to achieve the performance required to probe the low-mass region of the parameter space with a sensitivity never reached before. In this paper, new results on the performance and an overview of the CRESST-III detectors will be presented, emphasizing the results about the low-energy threshold for nuclear recoil of CRESST-III Phase 1 which started collecting data in August 2016. Keywords: Cryogenic detectors; Dark matter; Rare-event searche
Evaluation of gingival crevicular fluid adrenomedullin and human neutrophil peptide 1-3 levels of patients with different periodontal diseases
PubMed ID: 20151808Background: Antimicrobial peptides participating in the innate host response are important contributors for maintaining the balance between health and disease. The aim of the present study is to investigate the levels of gingival crevicular fluid (GCF) adrenomedullin and human neutrophil peptides 1 through 3 (HNP1-3) in patients with different periodontal diseases. Methods: A total of 77 subjects, including 20 patients with chronic periodontitis, 18 patients with generalized aggressive periodontitis, 20 patients with gingivitis, and 19 healthy subjects, were included in the present study. The probing depth, clinical attachment level, plaque index, and papilla bleeding index were assessed in all study subjects. GCF samples were analyzed for evaluating adrenomedullin and HNP1-3 levels by enzyme-linked immunosorbent assay. Results: The present study demonstrated that the periodontitis groups had a significantly higher total amount of GCF adrenomedullin compared to the gingivitis and healthy control groups after adjusting for age and gender (P 0.05). Conclusions: Our results suggest a defensive role for adrenomedullin during the host response in periodontal disease. Additionally, the lack of the HNP1-3 antimicrobial peptide might point to the deficiency of one of the protective mechanisms for periodontal tissues
Evaluation of the relationship between smoking during pregnancy and subgingival microbiota
PubMed ID: 15642061Background: Numerous studies have shown that smoking negatively affects periodontal health. Hormonal changes, which occur during pregnancy have also been reported to have adverse effects on the periodontal tissues or indirectly through alterations in the subgingival bacterial flora. At present, no knowledge exists concerning possible effects of smoking on the composition of subgingival plaque in pregnancy. The purpose of the present study was to evaluate the effects of smoking during pregnancy on the subgingival plaque bacteria most commonly associated with periodontal disease. Methods: A total number of 181 women were examined within 72 h post-partum. Smoking status was recorded by means of a self-reported questionnaire and the study population was divided into three groups; non-smokers, light smokers, and heavy smokers. In each woman, two subgingival plaque samples were obtained from mesio-or disto-buccal aspect of randomly selected one molar and one incisor tooth by sterile paperpoints. Clinical periodontal recordings comprising presence of dental plaque, bleeding on probing (BOP), and probing pocket depth (PPD) were performed at six sites per each tooth at all teeth. Plaque samples were analysed by checkerboard DNA-DNA hybridization with respect to 12 bacterial species. In all analyses, the individual subject was the computational unit. Thus, mean values for all clinical parameters were calculated and bacterial scores from each individual sample were averaged. Statistical methods included ?2 test, Kruskal-Wallis test and Mann-Whitney U-test. Results: Mean ages were similar in the study groups. Plaque, BOP and PPD recordings were lower in the heavy-smoker group, but the differences were not statistically significant (p > 0.05). The detection rates and bacterial loads of the specific subgingival bacteria exhibited no significant differences between the groups. No correlation could be found between smoking status and detection rates and bacterial loads of various bacterial species. Conclusion: The present findings suggest that smoking during pregnancy does not have a significant effect on the composition of subgingival plaque bacteria. © Blackwell Munksgaard, 2004
Periodontal infections and pre-term low birth weight: A case-control study
PubMed ID: 15691348Objective: Pre-term delivery of low-birth-weight infants [pre-term low birth weight (PLBW)] remains a significant public health issue and a major cause of neonatal death and long-term health problems. There is a growing consensus that infections remote from fetal-placental unit may influence PLBW infants. Recent studies have suggested that maternal periodontal disease may be an independent risk factor for PLBW. The purpose of the present study was to evaluate the possible link between periodontal infections and PLBW by means of clinical and microbiological data in post-partum women with low socioeconomic level. Methods: Clinical periodontal recordings comprising dental plaque, bleeding on probing, probing pocket depth and gingival recession were performed (six sites/tooth) in a total number of 181 women (53 cases and 128 controls) within 3 days post-partum. Subgingival plaque samples from mesio-or disto-buccal aspect of randomly selected one first molar and one incisor tooth have been obtained by paperpoints and were analysed by checkerboard DNA-DNA hybridization with respect to 12 bacterial species. In all analyses, the individual subject was the computational unit. Thus, mean values for all clinical parameters were calculated and bacterial scores from each individual sample were averaged. Statistical methods included Student's t-test, Fisher's exact test/?2 test, and multiple logistic regression analysis. Results: The cases have gained significantly less weight during the pregnancy than did the controls (p < 0.05). There were no statistically significant differences between the cases and controls with regard to the dental and periodontal parameters and the values of clinical periodontal recordings were found to be very similar (p > 0.05). Mean and median scores (bacterial loads) of Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, Actinobacillus actinomycetemcomitans, and Streptococcus intermedius in the subgingival plaque sampling sites were significantly higher in the controls than in the cases (p < 0.05). The occurrence rates of P. intermedia, Fusobacterium nucleatum, Peptostreptococcus micros, Campylobacter rectus, Eikenella corrodens, Selenomonas noxia and S. intermedius were higher in the cases compared with the controls, but the differences were not statistically significant (p > 0.05). According to the model created by the multiple logistic regression analysis, P. micros and C. rectus were found to significantly increase the risk of PLBW (p < 0.01 and p < 0.05 respectively), while P. nigrescens and A. actinomycetemcomitans decreased this risk (p < 0.01). Conclusion: The present findings indicated that when subgingival bacteria were evaluated together, P. micros and C. rectus may have a role in increasing the risk for PLBW, although no single bacteria exhibited any relation with the risk of PLBW. Further studies are required to better clarify the possible relationship between periodontal diseases and PLBW. Copyright © Blackwell Munksgaard 2005