Kernel-based methods for change detection in remote sensing images

Nowadays, the joint exploitation of images acquired daily by remote sensing instruments and of images available from archives allows a detailed monitoring of the transitions occurring at the surface of the Earth. These modifications of the land cover generate spectral discrepancies that can be detected via the analysis of remote sensing images. Independently from the origin of the images and of type of surface change, a correct processing of such data implies the adoption of flexible, robust and possibly nonlinear method, to correctly account for the complex statistical relationships characterizing the pixels of the images. This Thesis deals with the development and the application of advanced statistical methods for multi-temporal optical remote sensing image processing tasks. Three different families of machine learning models have been explored and fundamental solutions for change detection problems are provided. In the first part, change detection with user supervision has been considered. In a first application, a nonlinear classifier has been applied with the intent of precisely delineating flooded regions from a pair of images. In a second case study, the spatial context of each pixel has been injected into another nonlinear classifier to obtain a precise mapping of new urban structures. In both cases, the user provides the classifier with examples of what he believes has changed or not. In the second part, a completely automatic and unsupervised method for precise binary detection of changes has been proposed. The technique allows a very accurate mapping without any user intervention, resulting particularly useful when readiness and reaction times of the system are a crucial constraint. In the third, the problem of statistical distributions shifting between acquisitions is studied. Two approaches to transform the couple of bi-temporal images and reduce their differences unrelated to changes in land cover are studied. The methods align the distributions of the images, so that the pixel-wise comparison could be carried out with higher accuracy. Furthermore, the second method can deal with images from different sensors, no matter the dimensionality of the data nor the spectral information content. This opens the doors to possible solutions for a crucial problem in the field: detecting changes when the images have been acquired by two different sensors.

Treatment of advanced ovarian cancer with surgery, chemotherapy, and consolidation of response by whole-abdominal radiotherapy.

Between April 1981 and June 1985, 195 patients with ovarian cancer, International Federation of Gynecology and Obstetrics (FIGO) Stages IIB, IIC, III, and IV, entered a trial that consisted of surgery and chemotherapy with cisplatin (P) and melphalan (PAM) with or without hexamethylmelamine (HexaPAMP or PAMP regimens) every 4 weeks for 6 cycles. Because the intent was to study the outcome by treatment after evaluation of first-line chemotherapy, patients were evaluable only if the response was assessed by a second-look operation or if measurable disease progression was documented. One hundred fifty-eight patients (81%) were evaluable for response. Forty-five (28%) achieved pathologically confirmed complete remissions (pCR), and 24 of these patients received whole-abdominal radiation (WAR) for consolidation of response. Five patients with complete remission after WAR relapsed, as did nine of the 21 with complete remission who had not undergone WAR. The 3-year time to progression percentage (TTP +/- SE) from second-look operation was 70% +/- 7% for all patients who achieved pCR, 83% +/- 8% for those who received WAR, and 49% +/- 15% for those who did not receive WAR (this was not a randomized comparison). The 3-year TTP percentage for the 49 partial responders was 21% +/- 6%, identical for the 19 who had WAR and the 30 who had no radiation therapy. Additional or alternative methods for consolidation of pCR are needed since patients continue to relapse despite optimal initial response to therapy.

Colorectal cancer and thoracic surgeons: close encounters of the third kind.

Resection of lung metastases from colorectal cancer (CRC) is increasingly performed with a curative intent. This strategy was made possible in the 1990s by the development of new chemotherapeutic approaches, improved surgical techniques and better imaging modalities. However, evidence-based data showing clinical benefits of lung metastasectomy in this setting are nonexistent, and there are no prospective randomized trials to support the routine performance of these procedures for stage IV CRC. Current evidence suggests that resection of pulmonary metastases in combination with new cytotoxic agents, such as oxaliplatin, irinotecan and bevacizumab, may result in prolonged survival for many, and cure for a small minority of CRC patients who experienced tumor spread beyond the limits of the abdomen. This review focuses on the results of surgical management of CRC patients with lung metastases: we report the outcome of published series according to the presence or the absence of liver metastasis (and hepatic resection) prior to lung resection.

Développement de l'irrigation et évolution des régimes fonciers dans la région de Gaya (Niger)

Since the mid 90's, international actors as well as governmental actors have raised their interest into the development of irrigation's potential that is still largely unexploited in Niger. It seems all the more interesting as it could answer the needs of a fast growing population (3.3% per year). However, if everyone agrees on the need to development this system, the current implementation triggers questions on the process itself and its side effects. National and international policies on this matter were build upon an historical process through colonial, post-colonial and then the late 1980's neoliberal structures, leading to a business model that reveals a discrepancy between the state logic and the farming one. This business model asks for a high capacity of mobilization of resources unachievable for many, especially when they want to address small-scale irrigation (area purchase land. When there are only few areas available for selling, the. purchasing processes are undermining the farmers with insecure rights. If the withdrawal of lands is supposed to be smoothened by social measures, such as replacement of the land and primary offers to purchase the land, those measures are often not attractive. The proposed land of replacement is frequently too far away located or lesser fertile to be of any use and the economic capacity of purchasing is too little, eventually leading the farmers to leave their terroirs. Those in charge of the application of the Rural Code have succeeding in answering the need of written secured land tenure, but have difficulty to meet the challenge of doing the same to secure rights for farmers with loans or lease agreements. The small-scale irrigation could bring an answer for their financial needs to buy the land, but it would require mobilizing resources to invest or an easier access to supportive projects. The economic benefice from small-scale irrigation is now widely recognized, but we have to take also into account the risks of marginalization of part of the small farmers. For a more widely spread exploitation of small-scale irrigation, the mechanism of land regulation as well as the process to access the financial and technical support of projects must be revised in order to reach more small farmers. Développement de l'irrigation et évolution des régimes fonciers dans la région de Gaya (Niger) - Le secteur de l'irrigation a bénéficié d'un regain d'intérêt de la part des acteurs internationaux du développement et de l'Etat nigérien depuis le milieu des années 1990. Cet intérêt est à la hauteur du potentiel en terres irrigables (300Ό00 ha environ) du pays, largement sous-exploité alors que les besoins alimentaires sont grandissants, la population augmentant de 3.3% par an. Si le diagnostic est correct, les stratégies mises en oeuvre en matière d'irrigation posent question. Les interventions, aussi bien publiques qu'internationales, reposent sur un modèle entrepreneurial qui parachève une longue trajectoire historique. Initiée par l'Etat colonial, poursuivie par l'Etat post-colonial et transformé par les politiques néolibérales des années 1980, elle se caractérise par un hiatus constant entre logiques étatiques et logiques paysannes. En matière de petite irrigation privée (surfaces < 1-2 ha, technologies à faible coût), ce modèle présuppose une mobilisation de ressources (économiques, sociales, éducationnelles et foncières) inégalement réparties au sein de la population rurale. Cette recherche s'est intéressée à expliciter les liens qui existent entre le développement de la petite irrigation privée et l'évolution des régimes fonciers. Les trois questionnements qui ont guidé l'analyse empirique portent sur la sécurisation foncière, les dynamiques de marchandisation de la terre et l'accès à la terre pour tous les producteurs. Le Département de Gaya dispose d'un potentiel très important en ressources hydriques, facilement mobilisables. Les productions maraîchères et fruitières ont connu un essor très important à partir des années 1980. Initialement pratiquées par les cultivateurs, elles ont progressivement attiré l'attention d'acteurs externes au monde rural (fonctionnaires, commerçants), du fait de leur haute valeur ajoutée. La Banque mondiale a fortement soutenu cette dynamique à travers un projet à vocation entrepreneuriale, qui s'est pourtant révélé hors de portée de la majorité des petits paysans et a principalement bénéficié à ces acteurs extra-ruraux ainsi qu'à certaines élites locales. Au plan foncier, il a en particulier exclu tous les emprunteurs des terres, qui ne sont pas à même de produire des documents écrits confirmant leurs droits sur la terre. Ce projet, et plus largement l'intérêt que les acteurs extra-ruraux portent à la petite irrigation, ont contribué à alimenter la marchandisation de la terre. Sans ancrage familial dans les terroirs villageois, ces acteurs sont obligés d'acheter la terre pour faire de l'irrigation. Leur demande vient s'inscrire dans un contexte général où la pression démographique et le morcellement successif des capitaux fonciers familiaux ont progressivement individualisé la relation entre les producteurs et la terre, au point d'affaiblir ou de faire tomber les interdits coutumiers en matière de vente. Dans les espaces disposant de faibles réserves foncières, les ventes se font principalement au détriment des acteurs qui, comme les emprunteurs, disposent de droits fonciers peu stables et sécurisés. Si le retrait de la terre est socialement encadré (terre en remplacement, possibilité d'acheter la terre qui va être vendue), il pose également des contraintes agronomiques (sols de moindre qualité) et économiques (nécessité de disposer des liquidités pour racheter la terre) qui peuvent, en dernier ratio, obligent les acteurs concernés à quitter les terroirs. Les instances du Code rural, qui ont su apporter des réponses satisfaisantes à la demande de sécurisation foncière par l'établissement de documents écrits, rencontrent aujourd'hui de grandes difficultés à en faire de même pour les droits de prêt. Dans ce contexte, l'irrigation peut apporter les sommes nécessaires à l'achat des terres. Encore faut-il que ces emprunteurs disposent des ressources financières propres pour la développer ou qu'ils puissent y avoir accès grâce à l'appui d'un projet. Si l'intérêt économique de la petite irrigation privée est indiscutable, les risques de marginalisation d'une partie de producteurs ruraux qu'elle peut produire sont bien réels. Pour en faire une activité accessible au plus grand nombre, il faut revoir les mécanismes de régulation foncière, ainsi que les montages techniques et financiers qui supportent le développement de ce secteur d'activité très prometteur.

Updated survival data of the phase iii clinical trial of novottf-100a versus best standard chemotherapy for recurrent glioblastoma

NovoTTF-100A (TTF) is a portable device delivering low-intensity, intermediate-frequency, alternating electric fields using noninvasive, disposable scalp electrodes. TTF interferes with tumor cell division, and it has been approved by the US Food and Drug Administration (FDA) for the treatment of recurrent glioblastoma (rGBM) based on data from a phase III trial. This presentation describes the updated survival data 2 years after completing recruitment. Adults with rGBM (KPS ≥ 70) were randomized (stratified by surgery and center) to either continuous TTF (20-24 h/day, 7 days/week) or efficacious chemotherapy based on best physician choice (BPC). The primary endpoint was overall survival (OS), and secondary endpoints were PFS6, 1-year survival, and QOL. Patients were randomized (28 US and European centers) to either TTF alone (n ¼ 120) or BPC (n ¼ 117). Patient characteristics were balanced, median age was 54 years (range, 23-80 years), and median KPS was 80 (range, 50-100). One quarter of the patients had debulking surgery, and over half of the patients were at their second or later recurrence. OS in the intent-to-treat (ITT) population was equivalent in TTF versus BPC patients (median OS, 6.6vs. 6.0 months; n ¼ 237; p ¼ 0.26; HR ¼ 0.86). With a median follow-up of 33.6 months, long-term survival in the TTF group was higher than that in the BPC group at 2, 3, and 4 years of follow-up (9.3% vs. 6.6%; 8.4% vs. 1.4%; 8.4% vs. 0.0%, respectively). Analysis of patients who received at least one treatment course demonstrated a survival benefit for TTF patients compared to BPC patients (median OS, 7.8 vs. 6.0 months; n ¼ 93 vs. n ¼ 117; p ¼ 0.012; HR ¼ 0.69). In this group, 1-year survival was 28% vs. 20%, and PFS6 was 26.2% vs. 15.2% (p ¼ 0.034). TTF, a noninvasive, novel cancer treatment modality shows significant therapeutic efficacy with promising long-term survival results. The impact of TTF was more pronounced when comparing only patients who received the minimal treatment course. A large-scale phase III trial in newly diagnosed GBM is ongoing.

Procalcitonin for reduced antibiotic exposure in ventilator-associated pneumonia: a randomised study.

In patients with ventilator-associated pneumonia (VAP), guidelines recommend antibiotic therapy adjustment according to microbiology results after 72 h. Circulating procalcitonin levels may provide evidence that facilitates the reduction of antibiotic therapy. In a multicentre, randomised, controlled trial, 101 patients with VAP were assigned to an antibiotic discontinuation strategy according to guidelines (control group) or to serum procalcitonin concentrations (procalcitonin group) with an antibiotic regimen selected by the treating physician. The primary end-point was antibiotic-free days alive assessed 28 days after VAP onset and analysed on an intent-to-treat basis. Procalcitonin determination significantly increased the number of antibiotic free-days alive 28 days after VAP onset (13 (2-21) days versus 9.5 (1.5-17) days). This translated into a reduction in the overall duration of antibiotic therapy of 27% in the procalcitonin group (p = 0.038). After adjustment for age, microbiology and centre effect, the rate of antibiotic discontinuation on day 28 remained higher in the procalcitonin group compared with patients treated according to guidelines (hazard rate 1.6, 95% CI 1.02-2.71). The number of mechanical ventilation-free days alive, intensive care unit-free days alive, length of hospital stay and mortality rate on day 28 for the two groups were similar. Serum procalcitonin reduces antibiotic therapy exposure in patients with ventilator associated pneumonia.

On Consumer Decision Strategies: New Approaches for Studying and Aiding Preferential Choices

This dissertation focuses on the strategies consumers use when making purchase decisions. It is organized in two main parts, one centering on descriptive and the other on applied decision making research. In the first part, a new process tracing tool called InterActive Process Tracing (IAPT) is pre- sented, which I developed to investigate the nature of consumers' decision strategies. This tool is a combination of several process tracing techniques, namely Active Information Search, Mouselab, and retrospective verbal protocol. To validate IAPT, two experiments on mobile phone purchase de- cisions were conducted where participants first repeatedly chose a mobile phone and then were asked to formalize their decision strategy so that it could be used to make choices for them. The choices made by the identified strategies correctly predicted the observed choices in 73% (Experiment 1) and 67% (Experiment 2) of the cases. Moreover, in Experiment 2, Mouselab and eye tracking were directly compared with respect to their impact on information search and strategy description. Only minor differences were found between these two methods. I conclude that IAPT is a useful research tool to identify choice strategies, and that using eye tracking technology did not increase its validity beyond that gained with Mouselab. In the second part, a prototype of a decision aid is introduced that was developed building in particular on the knowledge about consumers' decision strategies gained in Part I. This decision aid, which is called the InterActive Choice Aid (IACA), systematically assists consumers in their purchase decisions. To evaluate the prototype regarding its perceived utility, an experiment was conducted where IACA was compared to two other prototypes that were based on real-world consumer decision aids. All three prototypes differed in the number and type of tools they provided to facilitate the process of choosing, ranging from low (Amazon) to medium (Sunrise/dpreview) to high functionality (IACA). Overall, participants slightly preferred the prototype of medium functionality and this prototype was also rated best on the dimensions of understandability and ease of use. IACA was rated best regarding the two dimensions of ease of elimination and ease of comparison of alternatives. Moreover, participants choices were more in line with the normatively oriented weighted additive strategy when they used IACA than when they used the medium functionality prototype. The low functionality prototype was the least preferred overall. It is concluded that consumers can and will benefit from highly functional decision aids like IACA, but only when these systems are easy to understand and to use.

Survival after lung metastasectomy in colorectal cancer patients with previously resected liver metastases.

BACKGROUND: Resection of hepatic metastases is indicated in selected stage IV colorectal cancer (CRC) patients. A minority will eventually develop pulmonary metastases and may undergo lung surgery with curative intent. The aims of the present study were to assess clinical outcome and identify parameters predicting survival after pulmonary metastasectomy in patients who underwent prior resection of hepatic CRC metastases.¦METHODS: We performed a retrospective analysis of 27 consecutive patients (median age 62 years; range: 33-75 years) who underwent resection of pulmonary metastases after previous hepatic metastasectomy from CRC in two institutions from 1996 to 2009. All patients underwent complete resection (R0) for both colorectal and hepatic metastases.¦RESULTS: Median follow-up was 32 months (range: 3-69 months) after resection of lung metastases and 65 months (range: 19-146 months) after resection of primary CRC. Three- and 5-year overall survival rates after lung surgery were 56 and 39%, respectively, and median survival was 46 months (95% CI 35-57). Median disease-free survival after pulmonary metastasectomy was 13 months (95% CI 5-21). At the time of last follow-up, seven patients (26%) had no evidence of recurrent disease and 6 of these 7 patients presented initially with a single lung metastasis.¦CONCLUSIONS: Resection of lung metastases from CRC patients may result in prolonged survival, even after previous hepatic metastasectomy. Yet, prolonged disease-free survival remains the exception, and seems to occur only in patients with a single lung lesion.

Unwanted sexual experiences among adolescents: shedding light on the gray zone between consensual and non-consensual sex.

This study aimed at exploring adolescents' perceptions of unwanted sexual experiences (USE) in order to set up definitions, categories, and boundaries on the continuum between consensual and non-consensual sex. METHODS: We conducted a qualitative thematic analysis of four focus group discussions gathering a total of 29 male and female adolescents aged 16-20 years. RESULTS: Analysis of participants' discourse revealed three main characteristics that define USE, namely, regret, as most situations discussed were said to be acceptable or not in terms of whether there were regrets after the fact; misperception of sexual intent; and lack of communication between partners. CONCLUSIONS: Our findings revealed that health professionals should be aware of the subtle aspects identifying USE when screening for situations that can have adverse psychological consequences. Where prevention is concerned, it appears important to address these aspects of USE in sex education classes.

Abcès du sein: privilégier la ponction-aspiration échoguidée [Ultrasonography-guided drainage should be considered as the first-line approach for breast abscesses treatment].

The abscesses of the breast are puerperal or non puerperal. The Staphylococcus aureus is the most common germ. The diagnosis is based on clinical criterias and confirmed by the ultrasonography. The percutaneous ultrasonography-guided drainage must be proposed in first intent to treat. Surgical treatment is still valid with a relapsing or chronic abscess, or after the non operative processes have failed.

Work values as predictors of entrepreneurial career intentions: A longitudinal analysis of gender effects

Purpose - Work values are an important characteristic to understand gender differences in career intentions, but how gender affects the relationship between values and career intentions is not well established. The purpose of this paper is to investigate whether gender moderates the effects of work values on level and change of entrepreneurial intentions (EI). Design/methodology/approach - In total, 218 German university students were sampled regarding work values and with EI assessed three times over the course of 12 months. Data were analysed with latent growth modelling. Findings - Self-enhancement and openness to change values predicted higher levels and conservation values lower levels of EI. Gender moderated the effects of enhancement and conservation values on change in EI. Research limitations/implications - The authors relied on self-reported measures and the sample was restricted to university students. Future research needs to verify to what extent these results generalize to other samples and different career fields, such as science or nursing. Practical implications - The results imply that men and women are interested in an entrepreneurial career based on the same work values but that values have different effects for men and women regarding individual changes in EI. The results suggest that the prototypical work values of a career domain seem important regarding increasing the career intent for the gender that is underrepresented in that domain. Originality/value - The results enhance understanding of how gender affects the relation of work values and a specific career intention, such as entrepreneurship.

Eating and weight related cognitions in people with Schizophrenia: a case control study

ABSTRACT: BACKGROUND: Patients with antipsychotic-induced weight gain (WG) regularly report on unsuccessful dietary trials, which suggests strong biological weight gain drive that is extremely hard to overcome with thoughts, such that behaviour doesn't change despite some intent to change. The purpose of the present study was to assess cognitions specifically related to restrained eating in severely overweight patients with schizophrenia treated with antipsychotic drugs. METHODS: Forty outpatients with schizophrenia and 40 controls without psychiatric disability were included. Both groups were composed of one subgroup severely overweight (defined as a BMI > 28), and a comparison sample (BMI<28). The revised version of the Mizes Anorectic cognitive questionnaire (MAC-R) was used in this cross-sectional case-control study. RESULTS: Gender was significantly related to eating disorders cognition, women scoring higher than men. Patients with schizophrenia in general scored higher on the MAC-R total scale and on the MAC-R subscale 2, the latter score representing rigid weight regulation and fear of weight gain. When comparing the two groups of subjects with BMI < 28, it appeared that patients with schizophrenia also scored higher on MAC-R total scale, the subscales 2 and 3, the latter subscale 3, indicating altered self control and self-esteem. CONCLUSION: As is the case in weight gain of subjects without schizophrenia, the present results suggest that the cognitive distortions, as assessed by the MAC-R, may play an important role in weight gain also in patients with schizophrenia, and in weight gain associated with antipsychotic pharmacotherapy. Particular attention to these processes may help to improve the management of antipsychotic drugs induced weight gain

Optimal public rationing and price response.

We study optimal public health care rationing and private sector price responses. Consumers differ in their wealth and illness severity (defined as treatment cost). Due to a limited budget, some consumers must be rationed. Rationed consumers may purchase from a monopolistic private market. We consider two information regimes. In the first, the public supplier rations consumers according to their wealth information (means testing). In equilibrium, the public supplier must ration both rich and poor consumers. Rationing some poor consumers implements price reduction in the private market. In the second information regime, the public supplier rations consumers according to consumers' wealth and cost information. In equilibrium, consumers are allocated the good if and only if their costs are below a threshold (cost effectiveness). Rationing based on cost results in higher equilibrium consumer surplus than rationing based on wealth.

Risk factors for survival after lung metastasectomy in colorectal cancer patients: a systematic review and meta-analysis.

BACKGROUND: Resection of lung metastases (LM) from colorectal cancer (CRC) is increasingly performed with a curative intent. It is currently not possible to identify those CRC patients who may benefit the most from this surgical strategy. The aim of this study was to perform a systematic review of risk factors for survival after lung metastasectomy for CRC. METHODS: We performed a meta-analysis of series published between 2000 and 2011, which focused on surgical management of LM from CRC and included more than 40 patients each. Pooled hazard ratios (HR) were calculated by using random effects model for parameters considered as potential prognostic factors. RESULTS: Twenty-five studies including a total of 2925 patients were considered in this analysis. Four parameters were associated with poor survival: (1) a short disease-free interval between primary tumor resection and development of LM (HR 1.59, 95 % confidence interval [CI] 1.27-1.98); (2) multiple LM (HR 2.04, 95 % CI 1.72-2.41); (3) positive hilar and/or mediastinal lymph nodes (HR 1.65, 95 % CI 1.35-2.02); and (4) elevated prethoracotomy carcinoembryonic antigen (HR 1.91, 95 % CI 1.57-2.32). By comparison, a history of resected liver metastases (HR 1.22, 95 % CI 0.91-1.64) did not achieve statistical significance. CONCLUSIONS: Clinical variables associated with prolonged survival after surgery for LM in CRC patients include prolonged disease-free interval between primary tumor and metastatic spread, normal prethoracotomy carcinoembryonic antigen, absence of thoracic node involvement, and a single pulmonary lesion.