AN INVESTIGATION OF RETINEX ALGORITHMS FOR IMAGE ENHANCEMENT

This letter introduces color constancy and Retinex theory for image enhancement.It clas- sifies Retinex algorithms into four categories and provides their principles and implementations in general.The experimental results of Frankle-McCann,MSR (Multi-Scale Retinex) and PNSD (Pro- jected Normalized Steepest Descent) Retinex algorithms are presented and compared.Moreover, variance and average gradient are proposed to evaluate the performance of the different algorithms.

Terminal Effect of Drop Coalescence on Single Drop Mass Transfer Measurements and Its Minimization

For the mass transfer to single drops during the stage of steady buoyancy-driven motion, experimental measurement is complicated with the terminal effect of additional mass transfer during drop formation and coalescence at the drop collector. Analysis reveals that consistent operating conditions and experimental procedure are of critical significance for minimizing the terminal effect of drop coalescence on the accuracy of mass transfer measurements. The novel design of a totally-closed extraction column is proposed for this purpose, which guarantees that the volumetric rate of drop phase injection is exactly equal to that of withdrawal of drops. Tests in two extraction systems demonstrate that the experimental repeatability is improved greatly and the terminal effect of mass transfer during drop coalescence is brought well under control.

Determination of volumetric changes at an underground stone mine： a photogrammetry case study

Photogrammetry, as a tool for monitoring underground mine deformation, is an alternative to traditional point measurement devices, and may be capable of accurate measurements in situations where technolo- gies such as laser scanning are unsuited, undesired, or cost-prohibitive. An underground limestone mine in Ohio is used as a test case for monitoring of structurally unstable pillars. Seven pillars were pho- tographed over in a 63 day period, punctuated by four visits. Using photogrammetry, point clouds of the mine geometry were obtained and triangulation surfaces were generated to determine volumes of change over time. Pillar spaUing in the range of 0.29-4.03 m3 of rock on individual rib faces was detected. Isolated incidents of rock expansion prior to failure, and the isolated failure of a weak shale band were also observed. Much of the pillars remained unchanged during the monitoring period, which is indicative of proper alignment in the triangulated surfaces. The photographs of some ribs were of either too poor quality or had insufficient overlap, and were not included. However, photogrammetry was successfully aonlied to multiole ribs in auantifving the oillar geometrv change over time.

Identity, Traditions and Lack of Environmental Behaviour

Place memories （traditions）, transmitted through art and the stories of a community, are key elements for the construction of individual and collective identity, connected to specific places. In this regard the authors examined how the representation of traditions affects place identity and in what ways the cultural heritage of the town might influence environmental forms of behaviour such as plans and projects. To this end the authors investigated the small town of Pagani in southern Italy, which has many ancient cultural traditions linked to specific locations and their rituals such as the festival of Our Lady of the Hens. Our contribution favours a qualitative approach in examining the data gathered and a participative methodology. The statistical analysis of the vocabulary distribution within 83 texts concerning town and its traditions, written by local citizens （52% male and 48% female） of different ages （range： 18-78） revealed a strong place identity. Narrative interviews （14） with key people were then analysed by means of grounded theory. In the perspective of conservation psychology the authors finally focussed on how feelings of impotence and social distrust influence relations between citizens and their local environment.

Radiographic and clinical analysis of cementless acetabular fixation in total hip arthroplasty

Objective： To investigate the factors affecting the fixation, loosening and therapeutic effect of cementless acetabular prosthesis through following up the patients with total hip arthroplasty clinically and radiographically. Methods： From February 1998 to May 1999, 139 patients （148 hips） underwent total hip arthroplasty with cementless acetabular prosthesis in our department. In this study, the clinical therapeutic effect and the anteroposterior radiographs of the pelvis and anteroposterior and lateral radiographs of the hips of 109 patients （116 hips） made before operation, at 1 week operation and annually 3, 6, and 12 months after thereafter were analyzed retrospectively. The clinical therapeutic effects were evaluated with Harris hip score. Radiographs were used to observe the position of prostheses and the bone changes around the implant, and to measure the wearing speed and direction of the acetabular cup. All evaluations were made by an independent examiner who did not participate in the operation. The patients were followed up for 5-6 years. Results- The mean Harris score was 44 points （ range, 10-70 points ） before operation, but it increased to 92.4 points （ range, 80-100 points） at the latest review after operation, which was significantly higher than that before operation （P 〈 0.05 ）. No acetabular component was revised because of infection or aseptic loosening. And no acetabular component migrated. There was no revision of fixed acetabular component because of pelvic osteolysis secondary to polyethylene wear. The mean linear wear rate was 0.15 mm per year. All the acetabular prostheses were classified as stable on the radiographs. Conclusions ： In terms of fixation, total hip arthroplasty with cementlcss acetabular components was successful. Although there is no aseptic loosening and a low incidence of osteolysis at the latest follow-up evaluation, polyethylene wear cannot be avoided and can lead to expansile osteolysis near the cups. This kind of osteolysis usually had no obvious clinical symptoms but it can be diagnosed early on radiographs. So radiographical follow-up for cementless acetabular components is very important.

Logistic Regression Analysis of Syndrome Essential Factors in Patients with Unstable Angina Pectoris

Objective: To explore the correlation between common syndrome essential factors and the symptoms and signs of unstable angina (UA). Methods: Eight hundred and fifteen patients with UA confirmed by coronary angiography were identified from several centers. Common syndrome essential factors were selected on the basis of expert experience. The correlations between common syndrome essential factors and symptoms and signs of UA were analyzed using binary logistic regression analysis. Results: The common syndrome essential factors in unstable angina were blood stasis, qi stagnation, phlegm turbidity, heat stagnancy, qi deficiency, yin deficiency, and yang deficiency. Symptoms such as chest pain, hypochondriac distention, ecchymosis, dark orbits, dark and purplish tongue, and tongue with ecchymosis and petechiae were significant diagnostic features of "blood stasis". Aversion to cold and cool limbs, weakness in the waist and knees, and clear abundant urine were significant diagnostic features of "yang deficiency". These results were in accordance with the understanding of traditional clinical Chinese medical practice. Conclusion: This clinical study analyzed the correlations between common syndrome essential factors and the symptoms and signs of unstable angina. The results provide the basis for establishing diagnostic criteria for syndrome essential factors.

Comparing techniques for measuring corticosterone in tadpoles

Glucocorticoids play a key role in mediating stress responses in vertebrates. Corticosterone （CORT） is the main glucocorticoid produced in amphibians, birds, and reptiles, and regulates several metabolic functions. The most common methods for quantifying CORT are competitive binding immunoassays： radioimmunoassay （RIA） and enzyme immunoassay （EIA）. RIA has been broadly used since the 1980＇s but it requires radioactivity. Commercial EIA kits permit quantifying hormone levels without radioactivity although the requirement for a larger sample volume may be a strong limitation for measurements involving larval amphibians. Here we used Xenopus laevis tadpoles to compare the performance of three commonly used procedures for determination of CORT： RIA on a chloroform extract of whole-body homogenate, EIA on plasma, and EIA on supematant of whole-body homogenate. We treated tadpoles with exogenous CORT at 0, 25, 50, and 100 nM. RIA could distinguish between 0 and 25 nM, and EIA on plasma between 0 and 50 nM, whereas whole-body homogenate EIA only detected significant differences between 0 and 100 riM. Each procedure presents advantages and disadvantages regarding sensitivity, the use of radioactivity, sample size, handling time, and economic cost. RIA is preferred when studying small-bodied animals from which blood samples cannot be obtained. When CORT level differences are intermediate and blood sampling is possible, EIA on plasma is a good non-radioactive alternative. EIA on whole-body homogenates may be useful to assess qualitative changes in CORT levels when considerable differences are expected. Finally, we discuss our findings in the context of previous studies on CORT in amphibians [Current Zoology 61 （5）： 835-845, 2015].