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71.
GPS-free Positioning in Mobile Ad Hoc Networks 总被引:30,自引:0,他引:30
We consider the problem of node positioning in ad hoc networks. We propose a distributed, infrastructure-free positioning algorithm that does not rely on GPS (Global Positioning System). Instead, the algorithm uses the distances between the nodes to build a relative coordinate system in which the node positions are computed in two dimensions. Despite the distance measurement errors and the motion of the nodes, the algorithm provides sufficient location information and accuracy to support basic network functions. Examples of applications where this algorithm can be used include Location Aided Routing [10] and Geodesic Packet Forwarding [2]. Another example are sensor networks, where mobility is less of a problem. The main contribution of this work is to define and compute relative positions of the nodes in an ad hoc network without using GPS. We further explain how the proposed approach can be applied to wide area ad hoc networks. 相似文献
72.
Ersland KM Christoforou A Stansberg C Espeseth T Mattheisen M Mattingsdal M Hardarson GA Hansen T Fernandes CP Giddaluru S Breuer R Strohmaier J Djurovic S Nöthen MM Rietschel M Lundervold AJ Werge T Cichon S Andreassen OA Reinvang I Steen VM Le Hellard S 《PloS one》2012,7(2):e31687
Background
Despite its estimated high heritability, the genetic architecture leading to differences in cognitive performance remains poorly understood. Different cortical regions play important roles in normal cognitive functioning and impairment. Recently, we reported on sets of regionally enriched genes in three different cortical areas (frontomedial, temporal and occipital cortices) of the adult rat brain. It has been suggested that genes preferentially, or specifically, expressed in one region or organ reflect functional specialisation. Employing a gene-based approach to the analysis, we used the regionally enriched cortical genes to mine a genome-wide association study (GWAS) of the Norwegian Cognitive NeuroGenetics (NCNG) sample of healthy adults for association to nine psychometric tests measures. In addition, we explored GWAS data sets for the serious psychiatric disorders schizophrenia (SCZ) (n = 3 samples) and bipolar affective disorder (BP) (n = 3 samples), to which cognitive impairment is linked.Principal Findings
At the single gene level, the temporal cortex enriched gene RAR-related orphan receptor B (RORB) showed the strongest overall association, namely to a test of verbal intelligence (Vocabulary, P = 7.7E-04). We also applied gene set enrichment analysis (GSEA) to test the candidate genes, as gene sets, for enrichment of association signal in the NCNG GWAS and in GWASs of BP and of SCZ. We found that genes differentially expressed in the temporal cortex showed a significant enrichment of association signal in a test measure of non-verbal intelligence (Reasoning) in the NCNG sample.Conclusion
Our gene-based approach suggests that RORB could be involved in verbal intelligence differences, while the genes enriched in the temporal cortex might be important to intellectual functions as measured by a test of reasoning in the healthy population. These findings warrant further replication in independent samples on cognitive traits. 相似文献73.
In vitro antimicrobial activity of propolis and synergism between propolis and antimicrobial drugs 总被引:3,自引:0,他引:3
The aim of this study was to investigate antimicrobial properties of ethanolic extract of 13 propolis (EEP) samples from different regions of Serbia against 39 microorganisms (14 resistant or multiresistant to antibiotics), and to determine synergistic activity between antimicrobials and propolis. Antimicrobial activity of propolis samples was evaluated by agar diffusion and agar dilution method. The synergistic action of propolis with antimicrobial drugs was assayed by the disc diffusion method on agar containing subinhibitory concentrations of propolis. Obtained results indicate that EEP, irrespectively of microbial resistance to antibiotics, showed significant antimicrobial activities against Gram-positive bacteria (MIC 0.078%–1.25% of EEP) and yeasts (0.16%–1.25%), while Gram-negative bacteria were less susceptible (1.25&%ndash;>5%). Enterococcus faecalis was the most resistant Gram-positive bacterium, Salmonella spp. the most resistant Gram-negative bacteria, and Candida albicans the most resistant yeast. EEP showed synergism with selected antibiotics, and displayed ability to enhance the activities of antifungals. The shown antimicrobial potential of propolis alone or in combination with certain antibiotics and antifungals is of potential medical interest. 相似文献
74.
Srdjan Ljubisavljevic Ivana Stojanovic Slobodan Vojinovic Dragan Stojanov Svetlana Stojanovic Gordana Kocic Dejan Savic Tatjana Cvetkovic Dusica Pavlovic 《Cellular and molecular neurobiology》2013,33(6):767-777
Oxidative stress is revealed as the main contributor in the pathophysiology of neuroinflammation. Analyzing plasma and cerebrospinal fluid (CSF) of patients with different clinical phenotypes of neuroinflammation, defined as clinically isolated syndrome (CIS), and those defined as relapsing remitting multiples sclerosis (RRMS), we tested peripheral and CNS oxidative stress intensity in these neuroinflammatory acute attacks. All obtained values changes were assessed regarding clinical and radiological features of CNS inflammation. The obtained results revealed an increase in malondialdehyde levels in plasma and CSF in CIS and RRMS patients compared to control values (p < 0.05). The obtained values were most prevailed in both study group, CIS and RRMS, in patients with severe clinical presentation (p < 0.05). Measured activities of catalase and total superoxide dismutase were higher in CIS and RRMS patients in plasma compared to control values (p < 0.05), parallel with an increased catalase activity and decrease in superoxide dismutase activity in CSF regarding values obtained in control group (p < 0.05). The positive correlations regarding clinical score were obtained for all tested biomarkers (p < 0.01). Although the positive correlations were observed in MDA levels in plasma and CSF, for both study patients, and their radiological findings (p < 0.01), and a negative correlation in plasma SOD activity and CIS patients’ radiological findings (p < 0.01), no other similar correlations were obtained. These findings might be useful in providing the earliest antioxidative treatment in neuroinflammation aimed to preserve total and CNS antioxidative capacity parallel with delaying irreversible, later neurological disabilities. 相似文献
75.
Jack Tadanier Robert Hallas Jerry R. Martin Momir Cirovic Ruth S. Stanaszek 《Carbohydrate research》1981,92(2):191-205
Synthesis of 2-epi-fortimicin B has been accomplished by processes involving solvolyses of both 1-N-benzyloxycarbonyl- and 1-N-acetyl-2-O-(methylsulfonyl)fortimicins B, which occur with participation of the carbonyl oxygen atoms of the 1-N-acyl groups. The results illustrate both the greater effectiveness of acetamido groups in neighboring-group participation relative to benzyloxycarbonylamino groups, and the sensitivity of the nature of the products to the reaction conditions. 相似文献
76.
77.
Biljana Nikolić Mihailo Ristić Srdjan Bojović Zoran Krivošej Vlado Matevski Petar D. Marin 《化学与生物多样性》2015,12(2):295-308
The needle‐terpene profiles of two natural Pinus heldreichii populations from Mts. O?ljak and Gali?ica (Scardo‐Pindic mountain system) were analyzed. Among the 68 detected compounds, 66 were identified. The dominant constituents were germacrene D (28.7%), limonene (27.1%), and α‐pinene (16.2%). β‐Caryophyllene (6.9%), β‐pinene (5.2%), β‐myrcene (2.3%), pimaric acid (2.0%), α‐humulene (1.2%), and seven additional components were found to be present in medium‐to‐high amounts (0.5–10%). Although the general needle‐terpene profile of the population from Gali?ica was similar to those of the populations from Lov?en, Zeletin, Bjelasica, and Zlatibor‐Pe?ter (belonging to the Dinaric Alps), the principle‐component analysis (PCA) of seven terpenes (β‐myrcene, limonene, β‐elemene, β‐caryophyllene, α‐humulene, δ‐cadinene, and germacrene D‐4‐ol) in 121 tree samples suggested a partial divergence in the needle‐terpene profiles between the populations from the Scardo‐Pindic mountain system and the Dinaric Alps. According to previously reported data, the P. heldreichii samples from the Balkan‐Rhodope mountains lack β‐caryophyllene and germacrene D, but contain γ‐muurolene in their terpene profile. Differences in the terpene composition between populations growing in the three above‐mentioned mountain systems were compared and discussed. 相似文献
78.
Dragovic SM Hill T Christianson GJ Kim S Elliott T Scott D Roopenian DC Van Kaer L Joyce S 《Journal of immunology (Baltimore, Md. : 1950)》2011,186(12):6683-6692
Cytoplasmic Ags derived from viruses, cytosolic bacteria, tumors, and allografts are presented to T cells by MHC class I or class II molecules. In the case of class II-restricted Ags, professional APCs acquire them during uptake of dead class II-negative cells and present them via a process called indirect presentation. It is generally assumed that the cytosolic Ag-processing machinery, which supplies peptides for presentation by class I molecules, plays very little role in indirect presentation of class II-restricted cytoplasmic Ags. Remarkably, upon testing this assumption, we found that proteasomes, TAP, and endoplasmic reticulum-associated aminopeptidase associated with Ag processing, but not tapasin, partially destroyed or removed cytoplasmic class II-restricted Ags, such that their inhibition or deficiency led to dramatically increased Th cell responses to allograft (HY) and microbial (Listeria monocytogenes) Ags, both of which are indirectly presented. This effect was neither due to enhanced endoplasmic reticulum-associated degradation nor competition for Ag between class I and class II molecules. From these findings, a novel model emerged in which the cytosolic Ag-processing machinery regulates the quantity of cytoplasmic peptides available for presentation by class II molecules and, hence, modulates Th cell responses. 相似文献
79.
Kersevan K Valencic V Djordjevic S Simunic B 《Cellular & molecular biology letters》2002,7(2):367-369
Muscle responses to tetanic electrical stimulation were detected by the non-invasive tensiomyographic (TMG) measuring method. The main objective of this study was to find out whether the TMG measuring method is suitable for monitoring the unfused tetanus (stimulation frequencies ranging from 1 Hz to the fusion frequency (ff)--the frequency at which tetanus occurs), and whether this monitoring provides any information on skeletal muscles' structural or functional changes. The muscle adaptation process was observed in damped unfused tetanus (DUT). The measured results in the clinical environment as well as on the sports field indicate that DUT is caused by a type II muscle fibres fatigue process. Separate observation of type II muscle fibres enables more efficient treatment and observation of pathological changes, and helps professional athletes and their trainers to better understand the influence of training stimuli on the training process. 相似文献