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141.
Automated segmentation of blood vessels in retinal images can help ophthalmologists screen larger populations for vessel abnormalities. However, automated vessel extraction is difficult due to the fact that the width of retinal vessels can vary from very large to very small, and that the local contrast of vessels is unstable. Further, the small vessels are overwhelmed by Gaussian-like noises. Therefore the accurate segmentation and width estimation of small vessels are very challenging. In this paper, we propose a simple and efficient multiscale vessel extraction scheme by multiplying the responses of matched filters at three scales. Since the vessel structures will have relatively strong responses to the matched filters at different scales but the background noises will not, scale production could further enhance vessels while suppressing noise. After appropriate selection of scale parameters and appropriate normalization of filter responses, the filter responses are then extracted and fused in the scale production domain. The experimental results demonstrate that the proposed method works well for accurately segmenting vessels with good width estimation.  相似文献   
142.
Supply chain security is a major concern for logistics managers who have responsibility for inbound and outbound shipments to and from both domestic and international locations. We propose here that logistics decisions concerning security in the supply chain will be made more effectively when made in concert with decisions in related supply chain processes, especially supplier and carrier selection. Indeed, managers may minimize cost, transit time, and security risk by integrating decision processes internally, as well as with their carrier's and supplier's operations. Thus, we account for both intra‐firm collaboration between logistics and purchasing managers, as well as inter‐firm collaboration among buyers, suppliers, and carriers in a supply chain. In this paper, we propose a decision process that features a set of security rules and a multi‐objective optimization model to accomplish this aim. We then provide an illustration to demonstrate the potential usefulness of these concepts in practice.  相似文献   
143.
Approximately 75% of the PAF present in saliva is recovered on extraction of whole saliva (0.8 vol) with chloroform/methanol/water (2∶2∶1 v/v/v). PAF levels, determined by our recently developed radioimmunoassay, in saliva extracts ranged from 0.5–21 ng/mL with 59% between 2–6 ng/mL. These figures, for apparently healthy subjects, are higher than previously reported levels obtained by platelet assays. The validity of our radioimmunoassay results was checked by isolating and quantitating the PAF fraction from whole saliva. In addition, when we examined our saliva samples by platelet aggregation, low levels of PAF, comparable with the values found in the literature, were detected. Investigations revealed the presence of a substance(s) which inhibited PAF-induced platelet aggregation but which did not affect the radioimmunoassay.  相似文献   
144.
Yeast display is a powerful tool for increasing the affinity and thermal stability of scFv antibodies through directed evolution. Mammalian calmodulin (CaM) is a highly conserved signaling protein that undergoes structural changes upon Ca(2+) binding. In an attempt to generate conformation-specific antibodies for proteomic applications, a selection against CaM was undertaken. Flow cytometry-based screening strategies to isolate easily scFv recognizing CaM in either the Ca(2+)-bound (Ca(2+)-CaM) or Ca(2+)-free (apo-CaM) states are presented. Both full-length scFv and single-domain VH only clones were isolated. One scFv clone having very high affinity (K(d) = 0.8 nM) and specificity (>1000-fold) for Ca(2+)-CaM was obtained from de novo selections. Subsequent directed evolution allowed the development of antibodies with higher affinity (K(d) = 1 nM) and specificity (>300-fold) for apo-CaM from a parental single-domain clone with both a modest affinity and specificity for that particular isoform. CaM-binding activity was unexpectedly lost upon conversion of both conformation-specific clones into soluble fragments. However, these results demonstrate that conformation-specific antibodies can be quickly and easily isolated by directed evolution using the yeast display platform.  相似文献   
145.
Hot band annealing is known to be a prerequisite for good magnetic properties irrespective of manufacturing methods in grain‐oriented Fe‐3 wt.% Si electrical steels. In this study, the effects of hot band annealing on magnetic properties were investigated in 3% grain‐oriented electrical steels of low soluble AI contents and one‐stage cold rolling. Microstructure and precipitate distribution were compared with hot band annealing conditions. Secondary recrystallization behaviour with hot band annealing condition was also discussed.  相似文献   
146.
Few studies have examined the relationship between life events, suicide attempts, and personality disorders (PDs), in spite of the strong associations between PDs and suicidal behavior, and the poor coping strategies often exhibited by these individuals. The authors examined whether participants with PDs who attempted suicide during the first 3 years of a prospective, longitudinal study were more likely to experience specific life events in the month during and preceding the suicide attempt. Of 489 participants with PDs, 61 attempted suicide during the 3-year, follow-up interval. Results indicated that negative life events, particularly those pertaining to love-marriage or crime-legal matters, were significant predictors of suicide attempts, even after controlling for baseline diagnoses of borderline PD, major depressive disorders, substance use disorders, and a history of childhood sexual abuse. Therefore, certain types of negative life events are unique risk factors for imminent suicide attempts among individuals with PDs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
147.
The impact of HIV-related parental death on 414 adolescents was examined over a period of 6 years. The adjustment of bereaved adolescents was compared over 4 time periods relative to parental death and was also compared with the adjustment of nonbereaved adolescents. Bereaved adolescents had significantly more emotional distress, negative life events, and contact with the criminal justice system than nonbereaved youths; these behaviors did not remain significantly higher after parental death. Depressive symptoms and passive problem solving increased soon after parental death, as compared with nonbereaved adolescents. One year subsequent to parental death, depression and passive problem solving were similar to the levels of nonbereaved peers. Only sexual risk behaviors increased following parental death. These results suggest the importance of early family intervention soon after parental HIV diagnosis, prior to parental death, and sustained over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
148.
Visual search has been studied extensively, yet little is known about how its constituent processes affect subsequent emotional evaluation of searched-for and searched-through items. In 3 experiments, the authors asked observers to locate a colored pattern or tinted face in an array of other patterns or faces. Shortly thereafter, either the target or a distractor was rated on an emotional scale (patterns, cheerfulness; faces, trustworthiness). In general, distractors were rated more negatively than targets. Moreover, distractors presented near the target during search were rated significantly more negatively than those presented far from the target. Target-distractor proximity affected distractor ratings following both simple-feature and difficult-conjunction search, even when items appeared at different locations during evaluation than during search and when faces previously tinted during search were presented in grayscale at evaluation. An attentional inhibition account is offered to explain these effects of attention on emotional evaluation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
149.
Attention and working memory limitations set strict limits on visual representations, yet researchers have little appreciation of how these limits constrain the acquisition of information in ongoing visually guided behavior. Subjects performed a brick sorting task in a virtual environment. A change was made to 1 of the features of the brick being held on about 10% of trials. Rates of change detection for feature changes were generally low and depended on the pick-up and put-down relevance of the feature to the sorting task. Subjects' sorting decision suggests that changes may be missed because of a failure to update the changed feature. The authors also explore how hand and eye behavior are coordinated for strategic acquisition and storage of visual information throughout the task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
150.
Molybdenum dichalcogenides are semiconductors with layered type structure, which can act as efficient electrodes in the realization of photoelectrochemical solar cells. The main advantage of this molybdenum diselenide (MoSe2) semiconductor is the prevention of electrolyte corrosion because of the phototransitions involving non-bonding d-d orbital of the Mo atoms. Polycrystalline molybdenum diselenide thin films are prepared by pulsed electrodeposition on conducting glass and titanium substrates in galvanostatic mode from an ammoniacal solution of H2MoO4 and SeO2. The growth kinetics of the film was studied and the deposition parameters such as electrolyte bath concentration, bath temperature, time of deposition, deposition current, pH of the electrolyte and duty cycle of the current are optimized. X-ray diffraction analysis of the as deposited and annealed films showed the presence of highly textured MoSe2 films with polycrystalline nature. EDAX spectrum of the surface composition confirms the nearly stoichiometric MoSe2 nature of the film. Surface morphology studies by scanning electron microscope (SEM) shows that the films are pinhole free and of device quality nature. The optical absorption spectra show an indirect band gap value of 1.16 eV. Conductivity measurements were carried out at different temperatures and electrical constants such as activation energy, trapped energy state and barrier height were calculated.  相似文献   
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