65 research outputs found
The use of the eigenvectors of the spectral matrix. Seismic application
The spectral matrix filtering is a technique Chat enables separation of data
obtained front an antenna into a signal part and a noise part . In certain
circumstances it has been use for wave separation . The aim of the process
is to build models of propagation at the antenna level . Using these models
each wave is then estimated by a least-squares method .
When this process is applied to seismic data, the spectral matrix has to he
estimated in a special way . The estimation of models is particularly efficient using a time-domain representation of the eigenvectors of the
spectral matrix .
Two new separation processes are proposed, the matched model and the
tapered model . The scalar product of the two différent waves is a
parameter to be used when estimating the performance of the process .
Application to four différent types of seismic data illustrates the efficiency
of this type of filtering .La matrice spectrale est un outil utilisé pour séparer les signaux reçus sur une antenne en une partie signal et une partie bruit. Dans certains cas elle est utilisée pour séparer les ondes constituant la partie signal. La méthode consiste à estimer des modèles de propagation de ces ondes au niveau de l'antenne; les signaux sont alors obtenus par estimation aux moindres carrés. Appliquée à la sismique, cette méthode nécessite des opérations particulières d'estimation de la matrice spectrale. La détermination des modèles s'avère particulièrement efficace lorsque l'on utilise la représentation des vecteurs propres (de la matrice spectrale) dans le domaine temporel
Health services research into postnatal depression : results from a preliminary cross-cultural study
Background: Little is known about the
availability and uptake of health and
welfare services by women with postnatal
depression in different countries.
Aims: Within the context of a cross-
cultural research study, to develop and
test methods for undertaking quantitative
health services research in postnatal
depression.
Method: Interviews with service
planners and the collation of key health
indicators were used to obtain a profile of
service availability and provision. A service
use questionnaire was developed and
administered to a pilot sample in a number
of European study centres.
Results: Marked differences in service
access and use were observed between
the centres, including postnatal nursing
care and contacts with primary care
services.Rates of use of specialist services
were generally low.Common barriers to
access to care included perceived service
quality and responsiveness. On the basis of
the pilot work, a postnatal depression
version of the Service Receipt Inventory
was revised and finalised.
Conclusions: This preliminary study
demonstrated the methodological
feasibility of describing and quantifying
service use, highlighted the varied and
often limited use of care in this population,
and indicated the need for an improved
understanding of the resource needs and
implications of postnatal depression
Postnatal depression across countries and cultures : a qualitative study
Background: Postnatal depression seems to be a universal condition with
similar rates in different countries. However, anthropologists question the
cross-cultural equivalence of depression,
particularly at a life stage so influenced by
cultural factors.
Aims: To develop a qualitative method to explore whether postnatal depression is universally recognised, attributed and
described and to enquire into people’s
perceptions of remedies and services for
morbid states of unhappiness within the
context of local services.
Method: The study took place in 15 centres in 11 countries and drew on three groups of informants: focus groups with new mothers, interviews with fathers and
grandmothers, and interviews with health
professionals.Textual analysis of these three groups was conducted separately in each centre and emergent themes compared across centres.
Results: All centres described morbid unhappiness after childbirth comparable
to postnatal depression but not all saw this
as an illness remediable by health interventions.
Conclusions: Although the findings of
this study support the universality of a
morbid state of unhappiness following childbirth, they also support concerns
about the cross-cultural equivalence of postnatal depression as an illness requiring the intervention of health professionals;
this has implications for future research
Perceptions of postnatal depression across countries and cultures: from a TransCultural Study of PostNatal Depression (TCS-PND)
Objectives
The qualitative study was conducted within the international
“Transcultural study of postnatal depression (PND)” in 17 centres
located in 13 different countries. The aim was to explore
perceptions of PND by lay and professional key informants,
specifically regarding description of symptoms, awareness of this
pathology and of possible care.
Methods
Broad areas of inquiry and open-ended probes were developed by
the TCS-PND research group during international workshops to
obtain data comparable between countries on perceptions of
PND. A non-random convenience sampling method was used to
recruit postpartum mothers for focus groups, and fathers and
grandmothers for interviews. Influential healthcare planners and
clinicians were interviewed as professional key informants in each
centre. Within sites, transcripts of focus groups and interviews
underwent a process of text analysis in the original language until
exhaustive theme extraction was achieved. Themes (in English)
from all the centres were combined into broader categories and
after consensus discussions these categories were revalidated.
Results and discussion
Qualitative data were supplemented in each centre with sociodemographic
data to address the issues of: (i) whether perceptions
of PND are related to some specific cultural perception of mental
heath and/or of status of parenthood and (ii) how high or low
levels of general care and specificity of health policy relate to
differences in perception of needs for care. Data collected using
the same probes and methodology in different countries and
cultures has enabled a comparative analysis of perceptions of
PND. In addition it has shown that, although not described with
the same words, PND is a well-recognised condition by recent
mothers in all countries in this study. Data on focus groups and
interviews from selected countries are given in the following
abstracts to illustrate some similarities and differences in
perceptions between countries
Brazilian network for the surveillance of maternal potentially life threatening morbidity and maternal near-miss and a multidimensional evaluation of their long term consequences
<p>Abstract</p> <p>Background</p> <p>It has been suggested that the study of women who survive life-threatening complications related to pregnancy (maternal near-miss cases) may represent a practical alternative to surveillance of maternal morbidity/mortality since the number of cases is higher and the woman herself is able to provide information on the difficulties she faced and the long-term repercussions of the event. These repercussions, which may include sexual dysfunction, postpartum depression and posttraumatic stress disorder, may persist for prolonged periods of time, affecting women's quality of life and resulting in adverse effects to them and their babies.</p> <p>Objective</p> <p>The aims of the present study are to create a nationwide network of scientific cooperation to carry out surveillance and estimate the frequency of maternal near-miss cases, to perform a multicenter investigation into the quality of care for women with severe complications of pregnancy, and to carry out a multidimensional evaluation of these women up to six months.</p> <p>Methods/Design</p> <p>This project has two components: a multicenter, cross-sectional study to be implemented in 27 referral obstetric units in different geographical regions of Brazil, and a concurrent cohort study of multidimensional analysis. Over 12 months, investigators will perform prospective surveillance to identify all maternal complications. The population of the cross-sectional component will consist of all women surviving potentially life-threatening conditions (severe maternal complications) or life-threatening conditions (the maternal near miss criteria) and maternal deaths according to the new WHO definition and criteria. Data analysis will be performed in case subgroups according to the moment of occurrence and determining cause. Frequencies of near-miss and other severe maternal morbidity and the association between organ dysfunction and maternal death will be estimated. A proportion of cases identified in the cross-sectional study will comprise the cohort of women for the multidimensional analysis. Various aspects of the lives of women surviving severe maternal complications will be evaluated 3 and 6 months after the event and compared to a group of women who suffered no severe complications in pregnancy. Previously validated questionnaires will be used in the interviews to assess reproductive function, posttraumatic stress, functional capacity, quality of life, sexual function, postpartum depression and infant development.</p
Postpartum psychiatric disorders
Pregnancy is a complex and vulnerable period that presents a number of challenges to women, including the development of postpartum psychiatric disorders (PPDs). These disorders can include postpartum depression and anxiety, which are relatively common, and the rare but more severe postpartum psychosis. In addition, other PPDs can include obsessive–compulsive disorder, post-traumatic stress disorder and eating disorders. The aetiology of PPDs is a complex interaction of psychological, social and biological factors, in addition to genetic and environmental factors. The goals of treating postpartum mental illness are reducing maternal symptoms and supporting maternal–child and family functioning. Women and their families should receive psychoeducation about the illness, including evidence-based discussions about the risks and benefits of each treatment option. Developing effective strategies in global settings that allow the delivery of targeted therapies to women with different clinical phenotypes and severities of PPDs is essential
Carte géologique de l'Algérie à 1/50 000 - Arba
Cartothèque Sciences de la Terre Lyon 1 - http://hola.univ-lyon1.fr/ipac20/ipac.jsp?session=&profile=geol&menu=searchCarte géologique d'Algérie détaillée, Arba, échelle 1/50 000, feuille 42, éditée par le Service géologique d'Algéri
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