Usefulness of ultrasonography and computerized tomography in predicting resectability of pancreatic carcinoma

BACKGROUND: Surgical resection is the only curative treatment of pancreatic carcinoma (PC). An accurate assessment of the extension of PC is mandatory to select appropriate patients to this therapeutic option. This study was aimed at assessing the usefulness of abdominal ultrasonography (US) and computed tomography (CT) to establish tumoral staging and to predict tumor resectability. PATIENTS AND METHODS: Between January 1990 and December 1995, 84 PC patients were submitted to surgical procedures (potentially curative resection in 30%, biliodigestive anastomosis in 51% and exploratory laparotomy in 13%). Preoperative staging was carried out by means of abdominal US and/or CT. Definitive staging was established according to surgical findings, using the TNM classification. RESULTS: Accuracy of preoperative evaluation with regard to tumoral staging was 65%, being underestimated in 29 (35%) patients. This underestimation was mainly due to lesions in stage I. In addition, preoperative staging predicted tumor unresectability with a 50% sensitivity and a 83% specificity. CONCLUSIONS: US and CT have a good specificity in the staging and unresectability prediction of pancreatic cancer. However, their usefulness is limited by their low sensitivity.     

Fusing Visual and Inertial Sensing to Recover Robot Ego‐motion

A method for estimating mobile robot ego‐motion is presented, which relies on tracking contours in real‐time images acquired with a calibrated monocular video system. After fitting an active contour to an object in the image, 3D motion is derived from the affine deformations suffered by the contour in an image sequence. More than one object can be tracked at the same time, yielding some different pose estimations. Then, improvements in pose determination are achieved by fusing all these different estimations. Inertial information is used to obtain better estimates, as it introduces in the tracking algorithm a measure of the real velocity. Inertial information is also used to eliminate some ambiguities arising from the use of a monocular image sequence. As the algorithms developed are intended to be used in real‐time control systems, considerations on computation costs are taken into account. © 2004 Wiley Periodicals, Inc.     

A projectively invariant intersection test for polyhedra

Although intersection relations are projectively invariant, most existing intersection detection tests for arbitrary polyhedra can give different results before and after a nonsingular arbitrary projective transformation of the polyhedra under test. This paper presents a projectively invariant intersection test for general polyhedra whose only numerical part is the computation of 4×4 determinants of homogeneous vertex coordinates. Degeneracies are resolved using a technique of symbolic infinitesimals which also reduces to the computation of 4×4 determinants. This greatly simplifies the implementation of the test in hardware. Moreover, its projective invariance permits applying it at any point in the graphics pipeline. Since no auxiliary geometric entities need to be computed, the presented test can be concisely expressed as a Boolean formula, instead of a procedure. Published online: 15 March 2002 Correspondence to: F. Thomas     

Synthesis of slow‐wave structures based on capacitive‐loaded lines through aggressive space mapping (ASM)

This article is focused on the automated synthesis of slow‐wave structures based on microstrip lines loaded with patch capacitors. Thanks to the presence of the shunt capacitors, the effective capacitance of the line is enhanced, and the phase velocity of the structure can be made significantly smaller than the one of the unloaded line. The target is to achieve the layout of the slow‐wave structure able to provide the required slow‐wave ratio, characteristic (Bloch) impedance and electrical length (i.e., the usual specifications in the design of slow‐wave transmission lines). To this end, a two‐step synthesis method, based on the aggressive space mapping (ASM) algorithm, is proposed for the first time. Through the first ASM algorithm, the circuit schematic providing the target specifications is determined. Then, the second ASM optimizer is used to generate the layout of the structure. To illustrate the potential of the proposed synthesis method, three application examples are successfully reported. The two‐step ASM algorithm is able to provide the layout of the considered structures from the required specifications, without the need of an external aid in the process. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:629–638, 2015.     

Rank Estimation in Missing Data Matrix Problems

A novel technique for missing data matrix rank estimation is presented. It is focused on matrices of trajectories, where every element of the matrix corresponds to an image coordinate from a feature point of a rigid moving object at a given frame; missing data are represented as empty entries. The objective of the proposed approach is to estimate the rank of a missing data matrix in order to fill in empty entries with some matrix completion method, without using or assuming neither the number of objects contained in the scene nor the kind of their motion. The key point of the proposed technique consists in studying the frequency behaviour of the individual trajectories, which are seen as 1D signals. The main assumption is that due to the rigidity of the moving objects, the frequency content of the trajectories will be similar after filling in their missing entries. The proposed rank estimation approach can be used in different computer vision problems, where the rank of a missing data matrix needs to be estimated. Experimental results with synthetic and real data are provided in order to empirically show the good performance of the proposed approach.     

Chromatic parameters and oxidation indices for edible vegetable oils submitted to thermal oxidation

Peroxide values, TBA numbers and chromatic parameters of edible vegetable oils (olive, sunflower, corn oils) thermally oxidised (75°C, 100°C, 180°C) during 5 days were determined. For calculating chromatic parameters the recommended standard CIE methods and several simplified methods were employed. With olive oil a remarkable change in spectral characteristics occurred as the temperature and time of heating were increased. Thermal autoxidation, as assessed by peroxide value and TBA number, was only observed at 75°C (Schaal oven test). In none of the three types of vegetable oil was the dominant wavelength modified during the course of the heating process. Luminosity and hue angle showed slight increases in olive and sunflower oils. Colour saturation underwent a remarkable decrease in olive oil. From a comparison and a correlation study it is concluded that the simplified methods could be applied only for certain chromatic parameters and types of vegetable oil. For a comprehensive study of the diverse chromatic parameters the standard CIE methods should be applied.     

Herd-level and territorial-level factors influencing average herd somatic cell count in France in 2005 and 2006

Mastitis is a multifactorial disease and the most costly dairy production issue. In spite of extensive literature on udder-health risk factors, effects of metabolic diseases, farmers' competencies and livestock farming system on somatic cells count (SCC) are sparsely described. Herd-level or territorial-level factors affecting monthly composite milk weighted mean cow SCC (CMSCC) were analysed with a linear mixed effect model. The average CMSCC was 266,000 cells/ml. Half of the herds had CMSCC >300,000 cells/ml for 2-6 months a year, and 15% of herds for more than 7 months a year. CMSCC was positively associated with the number of cows, having a beef or fattening herd in addition to the dairy herd, the monthly average days in milk, the yearly age at first calving, the yearly proportion of purchased cows and the yearly culling rate. Moreover, a positive association is reported between CMSCC and the monthly proportion of cows probably with subacute ruminal acidosis (fat percentage minus protein percentage ≤0·30%, for Holstein) and negative energy balance (protein to fat ratio ≤0·66, for Holstein), the yearly average calving interval, having at least one dead cow and the mean monthly temperature. The association was negative for a predominant breed other than Holstein, the monthly milk production, the yearly dry-off period length, the monthly first calving cow proportion, having an autumn calving peak, being a Good Breeding Practices member, the monthly number of days with rain, the altitude and the territorial cattle density. CMSCC varied widely among the 11 dairy production areas. In conclusion, this study showed the average CMSCC for the French dairy cows, compared with international results. Moreover, it quantified the contribution of several factors to CMSCC, in particular metabolic diseases and the farm environment.     

Comparison of Various Procedures Employed in the TBA Test of Spanish Edible Vegetable Oils

A comparison of the TBA single extraction procedure in relation to the TBA distillation and TBA heating reflux procedures on Spanish edible vegetable oils was carried out. V/e have emphasized taking up the TBA single extraction procedure to obtain more precise results on the vegetable oils samples. The better correlation (r=0.864) was shown between the single extraction and heating reflux procedures. Mean TBA values obtained by the distillation and heating reflux procedures (heating samples) were higher than those obtained through the single extraction procedure. Samples packed in “tetrabrik” showed TBA values higher than those packed in PVC containers (p<0.01).     

Prevalence of monosymptomatic celiac disease in patients with iron deficiency anemia

A prospective study of the prevalence of monosymptomatic celiac disease presented as ferropenic anemia in patients admitted for study such complication of was carried out. All the patients were evaluated by gastroscopy and biopsy of the distal duodenal segment, regardless of endoscopic appearance. Patients presenting an endoscopic lesion clearly suggestive as the origin of the chronic bleeding were excluded from the study. The prevalence of celiac disease, the only manifestation of which was ferropenic anemia, was 3.3% in this series. What is important to note in this study is the importance of duodenal biopsy in the study of ferropenic anemia, with the aim of avoiding diagnostic delay of a possible monosymptomatic celiac disease as the cause of the anemia.     

Comparative studies of female sex pheromone components and male response of the corn stalk borer Sesamia nonagrioides in three different populations

Studies to determine possible differences in the pheromone communication system of three different populations of the corn stalk borer Sesamia nonagrioides (Lef.) in France, Spain, and Greece were carried out. The two main pheromone components (Z)-11-hexadecenyl acetate (Z11–16:Ac) and (Z)-11-hexadecenol (Z11–16:OH), were detected in all analyses with very small differences in the three populations. Among the minor components, analyzed by GC-MS on concentrated gland extracts from French and Greek origin females, (Z)-11-hexadecenal (Z11–16:Ald) was detected in minor amounts. Wind-tunnel and field studies revealed similar a male response in the three populations to pheromone glands extracts and synthetic pheromone regardless of the female/male origin. The results do not support the assumption of the existence of different pheromone types of the corn stalk borer S. nonagrioides due to geographic isolation.