Vectorizing the spatial structure of high-harmonic radiation from gas.

Strong field laser physics has primarily been concerned with controlling beams in time while keeping their spatial profiles invariant. In the case of high harmonic generation, the harmonic beam is the result of the coherent superposition of atomic dipole emissions. Therefore, fundamental beams can be tailored in space, and their spatial characteristics will be imparted onto the harmonics. Here we produce high harmonics using a space-varying polarized fundamental laser beam, which we refer to as a vector beam. By exploiting the natural evolution of a vector beam as it propagates, we convert the fundamental beam into high harmonic radiation at its focus where the polarization is primarily linear. This evolution results in circularly polarized high harmonics in the far field. Such beams will be important for ultrafast probing of magnetic materials.

Adaptive Compressive Tomography with No a priori Information.

Quantum state tomography is both a crucial component in the field of quantum information and computation and a formidable task that requires an incogitable number of measurement configurations as the system dimension grows. We propose and experimentally carry out an intuitive adaptive compressive tomography scheme, inspired by the traditional compressed-sensing protocol in signal recovery, that tremendously reduces the number of configurations needed to uniquely reconstruct any given quantum state without any additional a priori assumption whatsoever (such as rank information, purity, etc.) about the state, apart from its dimension.

A closed-form unsupervised geometry-aware dimensionality reduction method in the Riemannian Manifold of SPD matrices.

Riemannian geometry has been found accurate and robust for classifying multidimensional data, for instance, in brain-computer interfaces based on electroencephalography. Given a number of data points on the manifold of symmetric positive-definite matrices, it is often of interest to embed these points in a manifold of smaller dimension. This is necessary for large dimensions in order to preserve accuracy and useful in general to speed up computations. Geometry-aware methods try to accomplish this task while respecting as much as possible the geometry of the original data points. We provide a closed-form solution for this problem in a fully unsupervised setting. Through the analysis of three brain-computer interface data bases we show that our method allows substantial dimensionality reduction without affecting the classification accuracy.

Status Report--Retracing the history of the early development of national chronic disease surveillance in Canada and the major role of the Laboratory Centre for Disease Control (LCDC) from 1972 to 2000.

TITRE: Rapport d'étape - Historique des débuts de la surveillance nationale des maladies chroniques au Canada et rôle majeur du Laboratoire de lutte contre la maladie (LLCM) de 1972 à 2000. INTRODUCTION: La surveillance de la santé consiste en l'utilisation systématique et continue de données sur la santé recueillies régulièrement en vue d'orienter les mesures de santé publique en temps opportun. Ce document décrit la création et l'essor des systèmes nationaux de surveillance au Canada et les répercussions de ces systèmes sur la prévention des maladies chroniques et des blessures. En 2008, les auteurs ont commencé à retracer l'historique des débuts de la surveillance nationale des maladies chroniques au Canada, en commençant à 1960, et ils ont poursuivi leur examen jusqu'en 2000. Une publication de 1967 a retracé l'historique de la création du Laboratoire d'hygiène de 1921 à 1967. Notre étude fait suite à cette publication et décrit l'historique de l'établissement de la surveillance nationale des maladies chroniques au Canada, à la fois avant et après la création du Laboratoire de lutte contre la maladie (LCDC).

Infections with Philometra sp. associated with mortalities in wild-hatched captive-raised striped bass, Morone saxatilis (Walbaum).

The striped bass, Morone saxatilis (Walbaum), once represented an important resource for fisheries in the St Lawrence River (Quebec, Canada). A restoration programme, involving captive propagation, was implemented with the objective of restocking the population, which had disappeared in the late 1960s. An unusually high rate of mortality was observed during the winter of 2006 in captive-raised fingerlings that were originally collected from the Miramichi River (New Brunswick, Canada) the previous summer. Post-mortem examinations revealed extensive granulomatous and hyperplastic peritonitis associated with numerous nematodes of the genus Philometra. Given the severity of the lesions, high intensity of infection by Philometra sp. was presumed to be the primary factor in the unusual mortalities reported that winter. Observations suggest that this nematode, which was acquired in the wild, cannot establish itself in a captive environment, most likely because of the absence of the obligate intermediate host. Examination of archived specimens of striped bass showed that this parasite was probably present in the St Lawrence River population prior to its extirpation. Consequently, the introduction of infected fish into this ecosystem should not be a concern. Nevertheless, infection-related mortalities of fingerlings might affect dynamics of wild striped bass populations.

[Damage control laparotomy for haemorragic abdominal trauma. A retrospective multicentric study about 109 cases]. / La laparotomie écourtée dans les traumatismes abdominaux hémorragiques. Etude multicentrique rétrospective sur 109 cas.

AIM OF THE STUDY: Damage control laparotomy is a new approach to the more severe abdominal traumas. It stems from a better understanding of the physiopathology of the haemorragic shock. PATIENTS AND METHODS: A national retrospective study from 27 centers about 109 trauma patients who underwent a damage control procedure between January 1990 and December 2001, is analysed. Surgical procedures included 97 hepatic packing, 10 abdominal packing, 4 exclusive skin closure, 1 open laparotomy technique and 3 digestive stapplings. RESULTS: The mortality rate is 42%. Eleven abdominal compartment syndromes have occurred with 7 decompressive laparomy (4 deaths). CONCLUSION: This study is based on the largest series of damage control laparotomy published in France. Results in terms of mortality and morbidity are similar to those of published studies from the USA.

Quality assurance for screening mammography: an international comparison.

STUDY OBJECTIVE: In 1998, the International Breast Cancer Screening Network (IBSN) sponsored an assessment of quality assurance policies and practices to define their scope for population-based screening mammography programmes across IBSN countries. DESIGN: Analysis of data from a survey designed to assess multiple elements of screening programme quality assurance, including organisation of quality assurance activities, mechanisms for site visits and accreditation, requirements for quality control and data systems, and inclusion of treatment, follow up, and programme evaluation in screening mammography quality assurance activities. PARTICIPANTS AND SETTING: IBSN representatives in 23 countries completed a comprehensive questionnaire between May and December 1998. MAIN RESULTS: Completed questionnaires were obtained from all 23 countries. Responses indicated that countries vary in their approaches to implementing quality assurance, although all monitor components of structure, process, and outcome. Nearly all have in place laws, surveillance mechanisms, or standards for quality assurance. In all countries, quality assurance activities extend beyond the screening mammography examination. CONCLUSIONS: The assessment has enhanced understanding of the organisation of screening mammography programmes across countries, as well as the comparability of screening mammography data. All countries have established mechanisms for assuring the quality of screening mammography in population-based programmes, although these mechanisms vary across countries.

Performance of screening mammography in organized programs in Canada in 1996. The Database Management Subcommittee to the National Committee for the Canadian Breast Cancer Screening Initiative.

BACKGROUND: The results of randomized trials show that breast cancer screening by mammography reduces breast cancer mortality by up to 40% in women aged 50-69 years. Because of these results, by 1998, 22 countries, including Canada, had established population-based organized screening programs. This paper presents the results of screening mammography in 1996 for 7 provincially organized breast cancer screening programs in Canada. METHODS: Analyses of interim performance indicators for screening mammography have been calculated from data submitted to the Canadian Breast Cancer Screening database. The data set consisted of data from 7 provincial programs and was limited to mammographic screens for women aged 50-69 years (n = 203,303). Screening outcomes and performance indicators were calculated for abnormalities detected by screening mammography only. RESULTS: The abnormal recall rate was 9.5% for first screens and 4.6% for subsequent screens, and the cancer detection rate per 1000 women screened was 6.9 for first screens and 3.8 for subsequent screens. The positive predictive value (i.e., the proportion of women who tested positive by mammography who were found to have breast cancer on screen-initiated diagnostic work-up) increased from 7.2% at the first screen to 8.2% at subsequent screens. Estimated participation rates within organized programs varied from 10.6% to 54.2%, depending on the province. INTERPRETATION: For 1996, organized breast cancer screening programs met or exceeded many of the interim measures used in international programs. It is possible to translate the benefits of breast cancer screening by mammography, as demonstrated in randomized trials, into population-based community programs. Screening mammography through organized programs should increase to allow more comprehensive monitoring in Canada.

[Liver transplantation with a graft taken from a heart transplant patient who was brain-dead]. / Transplantation hépatique avec un greffon prélevé chez un greffé cardiaque en état de mort cérébrale.

The shortage of organ donors has led to progressive softening of selection criteria for organ donation. We report on hepatic transplantation in a 55-year-old woman with primary biliary cirrhosis, whose donor was a 50-year-old heart transplant recipient who became brain stem dead, due to cerebral bleeding 8 months after transplantation. An orthotopic liver transplantation was performed. The postoperative course was uneventful and the recipient was alive and had normal liver function after a 42-month follow-up. Analysis of the literature included ethical consideration, potential hepatotoxic effects of immunosuppressive drugs and modification of the graft immunogenicity. It confirms that transplanted patients should not be a priori excluded from organ donation.

Breast cancer screening in 21 countries: delivery of services, notification of results and outcomes ascertainment.

Following clinical trial evidence of mammography screening's efficacy and effectiveness, data are needed from organized population-based programmes to determine whether screening in these programmes results in breast cancer mortality reductions comparable to those demonstrated in controlled settings. The International Breast Cancer Screening Network (IBSN) conducted two international programme assessments: in 1990 among nine countries and in 1995 among 22 countries, obtaining information on the organization and process for screening within breast cancer screening programmes. This manuscript describes procedures for recruitment, service delivery, interpretation and communication of results, case ascertainment, and quality assurance. Practices in more established programmes are compared with pilot programmes. Each IBSN country defined a unique programme of population-based breast cancer screening. Some programmes were sub-national rather than national in scope, while others were in pilot stages of development. Screening took place in dedicated centres in established programmes and in both dedicated and general radiology centres in pilot programmes. Although most countries used personal invitation systems to recruit women to screening, other recruitment mechanisms were used. Most countries used two-view mammography in their screening programmes. About half had implemented independent double reading of mammograms, considering it a key component of high-quality mammography screening. In conclusion, diversity exists in the organization and delivery of screening mammography internationally. Quality assurance activities are a priority and are being evaluated in the IBSN.

Molecular cloning and characterization of the cDNA encoding the rat liver gamma-butyrobetaine hydroxylase.

Carnitine biosynthesis from lysine and methionine involves five enzymatic reactions. gamma-butyrobetaine hydroxylase (BBH; EC 1.14. 11.1) is the last enzyme of this pathway. It catalyzes the reaction of hydroxylation of gamma-butyrobetaine to carnitine. The cDNA encoding this enzyme has been isolated and characterized. The cDNA contained an open reading frame of 1161 bp encoding a protein of 387 amino acids with a deduced molecular weight of 44.5 kDa. The sequence of the cDNA showed an important homology with the human cDNA recently isolated. Northern analysis showed gamma-butyrobetaine hydroxylase expression in the liver and in some extend in the testis and the epididymis. During this study, it also appeared that BBH mRNA expression was undetectable by Northern analysis during the perinatal period. During the development of the rat, the amount of BBH mRNA appeared after the weaning of the young rat and reached a maximal expression at the adult stage.

[Surgical treatment of acute cholecystitis. A retrospective study of a series of 192 patients operated on over a period of 3 years]. / Traitement chirurgical de la cholécystite aiguë. Etude rétrospective portant sur une série de 192 patients opérés en 3 ans.

Emergency conditions make laparoscopic treatment of acute cholecystitis challenging. The aim of this study is to retrospectively analyse our experience of cholecystectomy for acute cholecystitis performed between January 1995 and December 1997. In order to be included, patients had to present (i) symptoms of acute cholecystitis correlated with laboratory blood tests and ultrasonographic studies (ii) evidence of acute inflammation during the operation and (iii) histological confirmation of acute or subacute inflammation of the excised gallbladder. 192 patients were treated: 62 were totally managed laparoscopically (group CCN), 33 managed laparoscopically but required conversion to open cholecystectomy (group CCC) and 97 were managed conventionally by laparotomy (group CL). Mean age was significantly different between the three groups, (CCN: 55.6 +/- 15 years, CCC: 64.2 +/- 13 years, CL: 66.5 +/- 17 years), as was ASA score (CCN: ASA 3 and ASA 4: 16%, CCC: ASA 3 and ASA 4: 48%, CL: ASA 3 and ASA 4: 46%), and initial infectious signs (temp. > or = 38 degrees C: CCN: 35%, CCC: 39%, CL: 63%). Mean operative delay was significantly higher in the converted group [8.7 +/- 13 days (CCC) vs 4.5 +/- 8 days (CCN) and 5.4 +/- 8 days (CL)]. There were two (1%) bile duct injuries, one in the CCC group, the other in the CL group. Operative mortality was 2% (CCC: 0%, CCN: 0%, CL: 4%) and operative morbidity was 40% (CCN: 21%, CCC: 24%, CL: 57%). The mean postoperative hospital stay was shorter in the CCN group (6.5 +/- 3.5 days) and CCC group (9.6 +/- 4.4 days) vs the mean stay in the CL group (14.7 +/- 11.6 days). Appears to be beneficial for selected patients with low surgical risk to conclude laparoscopic cholecystectomy. It has yet to be shown whether this benefit can be extended to patients with a high surgical risk.

[Long-term outcome of a false lumen after surgical correction of type A acute aortic dissection]. / Evolution, à long terme, du chenal externe après cure chirurgicale des dissections aortiques aiguës de type A.

The long-term outcome (64.3 +/- 45 months) of 44 patients operated for acute dissection of at least the ascending aorta was assessed by regular clinical examination and annual CT scan. The diameter of the aorta at different levels was measured at each CT scan for all patients. Initially, 7 patients (16%) had acute dissection limited to the ascending aorta; none had a false lumen after surgery. No signs of aneurysmal dilatation were observed during follow-up of these patients. In the 37 other cases (84%) dissection of the aorta extended beyond the innominate artery; the false lumen remained patent distal to the prosthetic tube replacing the ascending aorta in 34 patients (92%). The false lumen was partially thrombosed in 8% of patients, leading to distal emboli in 1 patient. Moderate increases (less than 15 mm) in diameter of the false lumen were observed in 32% of patients; more severe dilatation (over 20 mm) was observed in 12% of patients. The management of dilatation of the false lumen is not standard; it depends mainly on the rate of progression and the clinical consequences. It is hoped that extension of the initial repair to the aortic arch, when the intimal tear is situated in this zone, will reduce the short and long-term progression of the false lumen.

Contrast sensitivity with soft contact lenses compensated for spherical aberration in high ametropia.

BACKGROUND: In optical systems, it is usual to compensate for longitudinal spherical aberration. In order to increase image quality, lens surfaces can be made aspheric to bring all object light rays into focus at the image plane. Theoretically, soft contact lenses with high power and spherical surfaces show significant amounts of spherical aberration. The use of spherical aberration-free soft contact lenses could therefore improve retinal image quality in the case of high ametropia. However, because of ocular aberration, accommodation effects, pupil dynamics, contact lens flexure, and positioning, the computation of the spherical aberration induced when a contact lens is placed on the eye is complicated. METHODS: In this study, the spatial contrast sensitivity (CS) of 61 high ametropes wearing soft contact lenses with, and without, in-air spherical aberration compensation is measured. RESULTS: A slightly better overall performance was found with the standard lenses. There was no significant influence by the type of ametropia, age, and gender. If individual results are considered, clinically significant differences between the two lens groups are observed in approximately 30% of the cases. CONCLUSIONS: It seems that correcting in-air soft contact lens spherical aberration systematically is of no clinical interest. However, selective manipulation of spherical aberration could, in high power soft contact lenses, significantly improve CS in individuals.

Suppression of the osmoinduced proline response of rapeseed leaf discs by polyamines.

Rapeseed leaf discs (RLD) subjected to upshock osmotic stress accumulate proline (Pro). Di- and polyamines (PA) supplied to the external medium suppressed Pro accumulation. These effects were dependent not only on diamine and PA concentrations but also on their cationic charge. The suppression of Pro accumulation required that diamine and PA be taken up and further accumulated in the leaf tissues. Glycine betaine (GB) also inhibited Pro accumulation, with the effects of GB and PA being additive. Experiments to elucidate the mechanism(s) responsible for the inhibitory effect of spermine (Spm) indicated that it could be simulated with methionine sulfoximine (MSO), a potent inhibitor of glutamine synthetase. The inhibitory effects of Spm and MSO were both alleviated by supplying glutamine to the RLD. In addition, Spm as well as MSO increased glutamate content, indicating that these compounds could inhibit the conversion of glutamate to proline. A comparison of the changes in chlorophyll and protein content of RLD osmotreated with or without added Spm indicates that this PA behaves as an antisenescent compound, preventing chlorophyll breakdown and proteolysis and hence the conversion of amino acids to Pro. Since the PA concentrations used in this work were much higher than the endogenous concentrations in RLD, the significance of PA under osmotic stress remains unclear. This study shows, however, that PA can suppress Pro accumulation.

[Primary treatment of left coronary artery diseases by percutaneous implantation of stents]. / Traitement en première intention des lésions du tronc commun de la coronaire gauche par implantation percutanée d'une endoprothèse.

Left main coronary artery (LM) stenting has only been reported in bail-out situations or absolute contraindications so surgery. The authors report the immediate and midterm results of primary Palmaz-Schatz stent implantation in two young patients without contraindication to surgery. The first patient, 58 year-old, was admitted for unstable angina in October 1994. Coronary angiography showed an isolated severe ostial lesion of the LM. After conferring with the surgical team which remained on stand-by, angioplasty and stent implantation were performed with excellent results, no complications and no restenosis on angiographic controls at 3 and 12 months. The patient remained asymptomatic 24 months later. The second patient, 38 year-old, was admitted in June 1995 for unstable angina, and coronary angiography showed a severe isolated stenosis in the middle of a long and wide LM. Primary coronary stenting was also performed with excellent results, no complication and no restenosis on angiographic controls at 4 and 8 months. This patient was still asymptomatic 16 months after stenting. These excellent immediate and medium-term results are encouraging and suggest that this form of treatment might be extended to patients with an isolated whether primary LM stent implantation could become a suitable alternative to surgery in the future.

Infrared pupillometry in presbyopes fitted with soft contact lenses.

The influence of pupil size, lens centration, and translation on multifocal contact lens performance suggests that these parameters should be accounted for in the optical design of presbyopic contact lenses. The purpose of the present article is to complete the existing experimental data with clinical measurements of pupil diameter and lens position relative to the pupil in a group of presbyopes, with controlled target luminance, stimulus distance, gaze angle, and convergence. The experiments involve an infrared video-pupillometer and ring-marked contact lenses. Results on pupil aperture show that the effect of changing target distance is comparable in magnitude to that of varying luminance within the photopic range. The measured data on lens position confirm that soft contact lenses are generally decentered from the pupillary axis, usually in inferior temporal direction, and that their average translation between primary and downward gaze is very small. It is also found that the average relative position between lens and pupil centers is slightly modified by changes of luminance in far vision. All these results provide characteristic values which are helpful for the optical modelling of presbyopic contact lenses.

[Mucinous ductal ectasia of the pancreas]. / Ectasie canalaire mucineuse du pancréas.

We report a new case of mucinous ductal extasia of the pancreas observed in a 64-year-old man with a history of chronic exocrine failure. Diagnosis was obtained by CT, duodenal endoscopy and retrograde cholangio-pancreatography. Risk of malignant degeneration and increased CA 19-9 led to duodenopancreatectomy. Histology confirmed the diagnosis but revealed no malignant lesion. After a 3-year follow-up, the patient is in excellent health. Based on this observation and a review of the literature, we present the characteristic features of mucinous ductal ectasia of the pancreas.

Executive summary.

The Canadian health system is at a crossroads. Significant health services restructuring is occurring across the country. This restructuring process provides a unique opportunity for Public Health and others to reorient the system away from illness to a focus on health--the health of individuals and communities. The purpose of this paper is to motivate and equip Public Health workers to take leadership in the restructuring, to outline key responses and strategies for Public Health associations, to raise public awareness about restructuring, and to challenge decision makers to integrate the Public Health perspective into the restructured health system. This Issue Paper describes the unique contributions Public Health has to offer health services restructuring, outlines the Public Health response to specific restructuring issues, and identifies some successful strategies for influencing change. Two key messages are explored in the paper: 1. Restructuring will be successful if it is based on an investment in health. The health of the public can be maintained and improved through changes to the institutional sector and support for health promotion, disease prevention and health protection services. 2. Public Health must be a full partner in the restructuring of health services. The Public Health perspective includes a broad understanding of the issues that are relevant to the health of individuals and communities. The skills and knowledge base offered through Public Health provide balance and equity in decision making, by ensuring full and representative involvement of community workers and the public. The uniqueness of Public Health is manifested in three distinct ways: its approach within an organized system of practice; its historical contribution; and its purposeful combination of perspectives, skills and knowledge. In partnership with communities, other health professionals and other health-determining sectors, Public Health works to protect, maintain and improve the health of Canadians. While other sectors undertake some of the functions outlined below, what makes Public Health unique is that these contributions are offered collectively through an organized system of practitioners to create a synergistic effect. Eight contributions of Public Health are identified in this paper. Specifically Public Health: Focuses on individuals and communities in a societal and global context. Builds capacity in individuals and communities to improve health. Facilitates community mobilization through community participation. Embraces promotion, prevention, protection. Influences the orientation of the health system toward health outcomes. Provides disease surveillance and control. Builds partnerships among sectors at the local level. Advocates for the health of the public. In addition to describing these contributions, the Issue Paper addresses the major trends in health services restructuring by providing an overview of the issues and outlining the Public Health response. While there is no one single model of restructuring occurring in the provinces and territories, many common themes exist. This paper highlights four categories of restructuring issues: I. Making a Difference in Health II. Skills and Knowledge Base III. Allocation of Financial Resources IV. Governance and Management.(ABSTRACT TRUNCATED AT 400 WORDS)

Thoracic versus lumbar administration of fentanyl using patient-controlled epidural after thoracotomy.

BACKGROUND AND OBJECTIVES: Epidural fentanyl injection can provide analgesia following thoracotomy, but where to insert the catheter is a matter of debate. The study compares the effects of thoracic and lumbar patient-controlled epidural fentanyl on analgesia, fentanyl requirements, and plasma levels after thoracotomy. METHODS: Thirty patients were randomized into two groups to receive either thoracic or lumbar patient-controlled epidural fentanyl for postoperative analgesia. Postoperative pain (10 cm, visual analog scale [VAS]) and fentanyl requirements were assessed every 4 hours for 24 hours and at 12-hour intervals for the next day. Fentanyl plasma levels were measured at 8 and 16 hours after surgery. Results were expressed as mean +/- 1 SD and analyzed using Student's t-test, ANOVA, and chi-square analysis at P < .05. RESULTS: Twenty-nine patients completed the study (14 in the lumbar and 15 in the thoracic group). The VAS scores and fentanyl requirements were not significantly different at any time interval in the thoracic group as compared to the lumbar group. VAS scores at 0 hours (4.6) and 4 hours (4.6) in the lumbar group were higher than VAS scores at 12 hours (2.8; P = .04), 16 hours (2.5; P = .02), and 20 hours (2.2; P = .01) in the same group. No significant difference was found between the fentanyl plasma levels of the two groups after 8 hours (lumbar, 0.26 +/- 0.37 ng/mL; thoracic, 0.22 +/- 0.20 ng/mL) or 16 hours (lumbar, 0.36 +/- 0.17 ng/mL; thoracic, 0.44 +/- 0.32 ng/mL). CONCLUSIONS: The authors concluded that there is little if any advantage of thoracic over lumbar patient-controlled epidural fentanyl administration in patients after thoracotomy with respect to analgesia, fentanyl requirements, and plasma levels.