Stepwise Criterion Research Articles

Adolescent Female Victims of Sexual Violence: Analysis of Loss of Follow-up after Emergency Care and Outpatient Follow-up.

To assess the loss to follow-up after emergency care and during 6-months of outpatient follow-up, and the associated variables, among adolescent sexual violence survivors. This is a retrospective study with review of the medical records of 521 females, aged 10 to 18 years, who received emergency care in a referral service in São Paulo, Brazil. The variables were sociodemographic; personal history; characteristics of abuse, disclosure, and reactions triggered after abuse (physical and mental disorders as well as social changes), psychotropic prescription needs, and moment of abandonment: after emergency care and before completing 6 months of outpatient follow-up. To compare groups of patients lost to follow-up at each time point, we used the Chi-square and Fisher exact tests followed by multiple logistic regression with stepwise criterion for selection of associated variables. We calculated the odds ratio with confidence interval (OR, CI 95%). The level of significance adopted was 5%. A total of 249/521 (47.7%) adolescents discontinued follow-up, 184 (35.3%) after emergency care and 65 (12.4%) before completing outpatient follow-up. The variables of living with a partner (OR = 5.94 [CI 95%; 2.49-14.20]); not having a religion (OR = 2.38 [CI 95%;1.29-4.38)]), having a Catholic religion [OR = 2.11 (CI 95%; 1.17-3.78)]; and not disclosing the abuse [OR = 2.07 (CI 95%; 1.25-3.44)] were associated with loss to follow-up after emergency care. Not needing mental disorder care (OR = 2.72 [CI 95%; 1.36-5.46]) or social support (OR = 2.33 [CI 95%; 1.09-4.99]) were directly associated with loss to outpatient follow-up. Measures to improve adherence to follow-up should be aimed at adolescents who live with a partner and those who do not tell anyone about the violence.

Pregnant women's knowledge of non-pharmacological techniques for pain relief during childbirth.

INTRODUCTIONThe objective of the study was to assess knowledge of pregnant women in the third trimester of pregnancy on non-pharmacological techniques for pain relief during labor and childbirth.METHODSA cross-sectional study was conducted at a tertiary care facility of the University of Campinas, Brazil. The participants were 171 pregnant women, aged 18–35 years with 36 or more weeks of a singleton pregnancy. Participants responded to a questionnaire with data about sociodemographic and obstetric characteristics, knowledge on non-pharmacological techniques for pain relief during childbirth, the source of the information on these techniques, practice of physical activity and occurrence of pain during pregnancy. Parous women responded on the use of non-pharmacological techniques for pain relief during childbirth in previous deliveries. Multiple regression analysis with stepwise criteria of selection of variables was used to identify variables significantly associated with knowledge of non-pharmacological techniques for pain relief during childbirth.RESULTSA total of 165 (96.5%) participants reported knowledge on at least one non-pharmacological technique; 87.1% on the use of a warm shower during labor for pain relief, 80.7% on the use of the birthing ball, and 74.8% on breathing techniques. There were no significant differences between nulliparous and parous women. The main source of information reported was the Internet. Multivariate analysis showed that pregnant women who had pain during pregnancy reported more knowledge on the use of warm showers during labor (OR=2.64; 95% CI: 1.03–6.73).CONCLUSIONSMost women had knowledge of at least one non-pharmacological technique for pain relief during childbirth.

Integration of Sentinel-2 Derived Spectral Indices and In-situ Forest Inventory to Predict Forest Biomass


 Forest biomass estimation is the central part of sustainable forest management to assess carbon stocks and carbon emissions from forest ecosystem. Sentinel-2 is state-of-art sensor with refined spatial and recurrent temporal resolution data. The present study explored the potential of Sentinel-2 derived vegetation indices for above ground biomass prediction using four regression models (linear, exponential, power and logarithmic). Sentinel-2 indices includes Global environmental monitoring index, transformed normalized difference vegetation index, normalized difference water index, normalized difference infrared index and red-edge normalized difference vegetation index. The performances of Sentinel-2 indices were assessed by simple single variable (index) based regression for GEMI, TNDVI, NDII, NDWI and RENDVI versus AGB values. Further, stepwise linear regression was also developed in which used all indices entered into stepwise selection and the best index was selected in the final model. Results showed that linear model of all indices performance best compared to the rest three models and R2 values 0.12, 0.39, 0.46, 0.44 and 0.37 for Global environmental monitoring index, transformed normalized. Vegetation index, normalized difference water index, infrared index and red-edge vegetation index, respectively. Normalized difference water index was considered the best index among five computed indices in simple linear as well as in stepwise linear regression, whereas rest of the indices were removed because they were not significant under the stepwise criteria. Further, the accuracy of normalized difference water index model was determined by root mean square error and final prediction model has 28.27 t/ha error for both simple linear and stepwise linear regression. Therefore, normalized difference water index was selected for biomass mapping and resultant biomass showed up to 339 t/ha in the study area. The resultant biomass map also showed consistency with global datasets which include global forest canopy height and global forest tree cover change maps. The study suggest that Sentinel-2 product has great potential to estimate above ground biomass with accuracy and can be used for large scale mapping in combination with national forest inventory for carbon emission accounting.
 

Differences in Maturity and Anthropometric and Morphological Characteristics among Young Male Basketball and Soccer Players and Non-Players.

Background: An aspect that influences sport performance is maturation status, since, within the same chronological age group, boys who have advanced maturation outperform their late maturing peers in tests of muscular strength, power, and endurance. Therefore, the aims of the present study were: (i) to investigate the differences in biological maturation and anthropometric and morphological characteristics among three groups of Italian adolescents, two of which were sportive (practicing basketball and football) and one non-sportive, and (ii) to identify the anthropometric and morphological predictors that best discriminate these three groups. Methods: Sixty-one basketball and 62 soccer players and 68 non-sportive youths were measured (mean age = 13.0 ± 1.1 y). Anthropometric characteristics were taken and body mass index, cormic index, body composition parameters, and somatotype were derived. An estimation of maturity status was carried out considering the years from peak height velocity (PHV). Two-way 3 × 3 ANOVAs was performed on all anthropometric characteristics to test the differences within sport groups and maturity status groups. Discriminant function analysis (stepwise criteria) was then applied to anthropometric and body composition variables to classify subjects into the three different sport categories. Results: Differences in anthropometric characteristics were detected among the three groups. For somatotype, differences among all of the considered groups were higher for endomorphy (p < 0.001; effect size = 0.13). Biological maturity influences the differences in the anthropometric characteristics and body composition among subjects of the same chronological age during adolescence. The variables that best discriminated the three groups were represented by body composition parameters, body proportions, and body build. Conclusions: This study confirms that boys who practice sport present healthier body composition parameters, with lower level of fat parameters. The assessment of maturity status is a fundamental factor in explaining anthropometric and body composition differences among peers in this period. Its comprehension may assist coaches and technical staff in optimizing competitive efficiency and monitoring the success of training regimes.

Women with premature ovarian failure using hormone therapy do not experience increased levels of depression, anxiety and stress compared to controls.

ObjectiveTo evaluate anxiety, depression and stress of POI women using hormone therapy. MethodsA quantitative cross-sectional study included 61 women diagnosed with POI receiving HT, and 61 women with preserved ovarian function, matched 1:1 for age (control group). Instruments used to evaluate depression, anxiety and stress were Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI) and Lipp's Stress Symptom Inventory (LSSI). The chi-square or Fisher's exact tests, Mann-Whitney test, Spearman's correlation coefficient or logistic regression analysis with stepwise criteria were used for analysis. ResultsThe mean age of POI women and control group was 35.03±7.68 and 34.49±7.55 years old (p = 0.63). POI group and control group had a mean of 0.44±0.92 and 1.28±1.38 children (p = 0,001); the total BDI, BAI and LSSI scores were 15.72±11.68 and 13.66±8.44 (p = 0.64); 17.54±13.16 and 17.25±11.05 (p = 0.90), 19.39±12.08 and 18.93±11.21 (p = 0.945). The majority of women did not have depression or presented mild depression, but approximately one-third had moderate-severe undiagnosed depressive or anxiety symptoms. In POI group, depression was positively correlated with the number of children and anxiety. Anxiety and stress were also positively correlated. It was observed that for each point in the BDI, the risk of stress above 20 increased 19.6%, while for each point in the BAI, the risk of greater stress increased 32.4%. LimitationsThis is a cross-sectional study, which made it impossible to draw cause and effect conclusions ConclusionWomen with POI receiving HT have indexes of depression, anxiety and stress similar to the population of women with preserved ovarian function.

The role of topography, stand and habitat features for management and biodiversity of a prominent forest hotspot of the Mediterranean Basin: Saproxylic beetles as possible indicators

Abstract The maintenance of biodiversity in forestlands has become one of the major concerns of global forestry. Regarding the situation of Italy, the Mediterranean forests belong to the less studied in Europe. There is an urgent need to individuate reliable indicators that help to assess forest features important for their future management and biodiversity. We focused our study on the largest forest hotspot of Southern Italy, the Sila National Park in Calabria, an upland covered by 130,000 ha of forest dominated by Calabrian black pine (Pinus nigra calabrica). We chose to test saproxylic beetle species as possible indicators of biodiversity and management. The main condition was the use of method and species useful also for forest managers. Data on the occurrence of 75 wood-inhabiting beetle species of body size approx. 1 cm and larger have been collected in 2010–2015 at 96 forest sites by multiple methods finally simplified in standardized visual census. For the suitability of individual species for indication, we used a novel hierarchical approach: starting from a model for the whole community. Target species were selected if they occupied more than 20% of the sites and non-obligate saproxylics were eliminated. These species’ responses were compared with that of the whole community and only concordant species were maintained as possible indicators. Species whose presence marked significantly species-rich habitats have evaluated as biodiversity indicators. Finally, conservation value model was used for validation. Two saproxylics met all the stepwise criteria used: Cucujus cinnaberinus and Clinidium canaliculatum. They provide a simple and useful tool for periodic diversity monitoring in nature reserve networks. Choosing easily identifiable species, rapidly detectable in a visual census as biodiversity indicators may greatly facilitate less expensive forest monitoring also by unspecialized forest managers.

Prevalence of household falls in long-lived adults and association with extrinsic factors.

ResumeObjective:to identify the prevalence of falls among older adults and the extrinsic factors associated with them. Method:population-based cross-sectional study with 350 older adults. A household survey was conducted using a questionnaire addressing socio-demographic, clinical, and environmental characteristics. Data were analyzed using Stata Software V.10. Pearson’s chi-square test and logistic regression analysis were used with stepwise criteria for selection of variables in the model, with measures of effect expressed in Prevalence Ratio. For input into the multiple model, the variables with p ≤ 0.20 were considered. All ethical care regarding research on human beings has been observed and respected. Results:the prevalence of falls was 46.9%. The extrinsic factors associated with falls were: stairs, uneven floor and pets in the main entrance, lack of anti-slip loose throw rugs and slippery floor in the kitchen, lack of anti-slip loose throw rugs and objects on the floor in the room, lack of grab bars in the shower, lack of grab bars in the toilet and switch away from the bathroom door (p <0.05). Conclusion:falls are frequent in long-lived adults. The identification of the extrinsic factors associated with the occurrence of this event can help in its prevention.

Double-edged effect? Impact of dual edge proximity on the distribution of ancient woodland indicator plant species in a fragmented habitat

The influence of edge proximity on woodland plants is a well-established research area, yet the influence of dual edge exposure has rarely been investigated. This novel research aims to establish whether proximity to two edges has any additive influence on Ancient Woodland Indicator (AWI) species presence relative to proximity to a single edge. Several AWI species are threatened and thus specific conservation priorities, while Ancient Semi-Natural Woodland (ASNW) itself is often highly fragmented: almost half of remnant patches are less than 5 ha, which increases the potential for dual edge effects. Here, systematic mapping of herbaceous AWI species was conducted in 310 vegetation plots in two formerly-connected ASNW fragments in South-West England. Linear regression modelling revealed that distance to nearest edge and distance to second nearest edge were both univariately positively correlated with AWI species richness. After distance from nearest edge was entered into a multivariate model first, distance from second edge was entered in a second optional step after meeting stepwise criteria. The resultant multivariate model was more significant, and explained more variance, than either variable in isolation, indicating an additive effect of dual edge exposure. Likewise, binary logistic regression modelling showed presence of individual AWI species (Anemone nemorosa, Hyacinthoides non-scripta, Lamiastrum galaeobdolon and Paris quadrifolia) was significantly related not only to distance from the nearest and second nearest edges in isolation, but significantly more strongly by the additive effect of distance from both edges in a single model. We discuss the implications of these findings from community ecology and conservation perspectives.

English

The Amazon rainforest is the world’s largest biome, containing almost 50% of the planet’s known biodiversity and is the biggest source of fresh water, which is approximately one-fifth of the global reserves. However, the sustainable use of this ecosystem is threatened by several factors, and deforestation is the main problem. This study addresses the deforestation of the Brazilian Amazon forest, in particular evaluate the determinants of the deforestation process, using for this purpose, time-series of several socioeconomic factors from 1990 to 2015. The methodology applied included statistical analyzes based on the application of multivariate discriminant analysis with the stepwise criteria. The results showed that in order of importance cattle, roads network, population, logging and crop areas were the determinant variables of the deforestation in the amazon. Key words: Cattle, population, deforestation, Brazilian Amazon.

Hotelling의 T-square 통계량을 이용한 강우유발 사면붕괴 예측

A new technique is presented to detect unstable slope behavior, based on Hotelling`s T2 analysis of pore pressure and water content obtained during flume tests using granitic and gneissic weathered soils. Three sets of pore pressure-water content values were simultaneously obtained during each test, and T2 statistics at the 90.0% and 95.0% confidence levels were calculated based on the correlations between values. The results show that unsuccessful detection of some local failures of the flume slope depended on the sensor position. In the case of global slope failures, anomalous behavior was detected between several hundred and several thousand seconds before the event as T2 statistics exceeded the confidence interval 90%. Hotelling`s T2 analysis provides a single control criterion because it enables correlations between diverse measured values within the same slope; the criterion also includes stepwise criteria for a forecasting and warning system based on confidence levels.

SAR Image Segmentation via Hierarchical Region Merging and Edge Evolving With Generalized Gamma Distribution

This letter proposes a novel segmentation algorithm for synthetic aperture radar (SAR) images based on hierarchical region merging and edge evolving. To cope with the influence of speckle in SAR images, a statistical stepwise criterion, the loss of log-likelihood function (LLF) of image partition, is utilized for region merging. For this merging procedure, precise distributions of image partitions are essential, and we employ the generalized gamma distribution (GΓD) for modeling SAR images. Besides, the traditional region merging methods often suffer from the initial image partition that may lead to coarse segment shapes. It motivates us introducing a novel edge evolving scheme into the segmentation algorithm. It consists of two iterative steps: the evolution of edge pixels with a maximum likelihood (ML) criterion and that with a maximum a posterior (MAP) criterion using a Markov random field (MRF) model. The performance of the proposed algorithm is validated on two actual SAR images from the AIRSAR and EMISAR systems.

Association Between Preoperative Statin Therapy and Postoperative Change in Glomerular Filtration Rate in Endovascular Aortic Surgery

Background Acute kidney injury during endovascular aortic repair can result in a reduction in the postoperative glomerular filtration rate (GFR). The ‘pleiotropic' effects of statins offer a potential mechanism of reducing the postoperative decline in the GFR. We therefore tested the hypothesis that in patients undergoing endovascular aortic repair, the GFR decreases less in patients taking preoperative statins than in those who do not. Methods A cohort investigation of 501 consecutive patients who underwent endovascular aortic repair between June 2005 and March 2007 in an academic tertiary care centre. Multivariable linear regression was used to assess the association between the statin use and the postoperative GFR, after adjusting for the baseline GFR and other confounding covariables selected using a stepwise criterion. Results The statin use was not associated with a change in the postoperative GFR (P=0.94); the difference (95% confidence interval) in the mean postoperative GFR (statins minus no statins) was estimated at 0.1 (−3.1, +3.4) ml min−1 1.73 m−2. A decrease in the GFR of ≥25% (the threshold to diagnose contrast-induced nephropathy) developed in 26 of 192 patients given statins before operation (13.5%) compared with 36 of 296 patients who were not taking statins (12.2%). Conclusions Statin therapy is not associated with a statistically significant change in the mean postoperative GFR in patients undergoing endovascular aortic surgery, nor a reduction in the risk of a GFR decline of >25%.

A new approach to confirming or excluding ventricular pre-excitation on a 12-lead ECG

The purpose of this study was to determine simple features of the standard 12-lead electrocardiogram (ECG) and incorporate them in a stepwise algorithm that would help confirm or exclude the presence of ventricular pre-excitation. We retrospectively analysed multiple variables on pre- and post-ablation ECGs in 238 patients with manifest accessory pathways that had been successfully ablated. A new variable, PR dispersion, was defined as a difference between maximum and minimum PR intervals on a single 12-lead ECG. A logistic regression analysis showed the combination of the following criteria to be powerful in the confirmation of the diagnosis in patients with suspected delta wave: presence of both PR interval < or = 120 ms and PR dispersion > or = 20 ms, absence of initial positive deflection (septal R wave) in lead augmented voltage right arm (aVR), and horizontal QRS transition in lead V1 or before. A stepwise algorithm was developed based on these criteria. Of the total 476 ECGs, seven patients with pre-excitation and one patient with normal ECG were misdiagnosed using the algorithm. Even though the retrospectively determined sensitivity and specificity of the three stepwise criteria were high (97% and 99%, respectively) a prospective study evaluating the algorithm is needed. Using a stepwise approach is a very sensitive and specific technique for excluding or confirming ventricular pre-excitation on a 12-lead ECG.

Localization of Accessory Pathways in the Wolff‐Parkinson‐White Pattern—Physician Versus Computer Interpretation of the Same Algorithm

There are several published algorithms for the prediction of accessory pathway (AP) location in the Wolff-Parkinson-White syndrome from the 12-lead electrocardiogram (ECG). Most depend on stepwise criteria, and minor disagreements between observers over QRS transition point or delta wave axis may lead to different classification of pathway location. We compared the utility of a computerized program in identifying pathway location from the ECG using the algorithm published by Fitzpatrick and coworkers(3) against physician assessment with the same algorithm. Thirty-one 12-lead ECGs with an overt preexcitation pattern were examined by three physicians and AP localized to one of eight anatomical sites using the Fitzpatrick algorithm, with disagreements resolved by consensus. Similarly, pathway location was determined by the Glasgow ECG program with the Fitzpatrick algorithm incorporated into its logic. The agreement between each physician and their consensus was 28/31, 29/31, and 29/31. Similarly, assessment by the Glasgow program produced agreement with the physician consensus in 29/31 cases. Of the 24 patients who underwent radiofrequency ablation, the program localized the pathway to the true or adjacent annular region in 20, compared to 20/24 by physician assessment of the algorithm, producing a similar predictive accuracy to published data. This study has shown that incorporation of the Fitzpatrick algorithm for AP location into a widely used computer program results in the same level of performance as that of experienced physicians and may be useful in clinical practice as an aid to referral for electrophysiological study and ablation.

Sintomas osteomusculares em professores do Ensino Fundamental

Musculoskeletal Symptoms in Elementary School Teachers Objective: To identify the occurrence of musculoskeletal symptoms in elementary school teachers. Method: A questionnaire containing an inventory for general and occupational data and the Nordic questionnaire were utilized. In the statistical analysis, subjects with and without symptoms over the last 12 months were compared for statistical analysis, independent of the symptom region and degree of severity. Univariate and multivariate logistic regression analysis was performed using a significance level of 5%. The stepwise criterion was utilized for the multivariate analysis. The variables were analyzed using the chi-squared test of association or Fisher’s test. Results: The participants’ average age was 40 years; 99.4% were women and 90.4% of them presented musculoskeletal symptoms. The regions most affected were: lower back, chest, neck, shoulders, wrists and hands. The presence of pain was significantly associated with absence of children (p = 0.03) and duration of professional activities shorter than or equal to 15 years (p = 0.03). In the multivariate analysis, the presence of pain in the neck region (odds ratio (OR): 6.2; 95% confidence interval (CI): 1.4–26.7), shoulders (OR: 2.8; 95% CI: 1.1–7.2), chest (OR: 2.5; 95% CI: 1.1–5.5) and wrists and hands (OR: 2.0; 95% CI: 1.0–3.9) presented significant associations with age less than 30 years, age 30–39 years, absence of children and absence of a stable relationship, respectively. Conclusion: Teachers presented high occurrence of musculoskeletal symptoms and this confirms the need for further studies.

Depressão e ansiedade nos cuidadores de mulheres em fase terminal de câncer de mama e ginecológico

PURPOSE: to evaluate the frequency of anxiety and depression in main caretakers of patients with terminal breast or gynecological cancer. METHODS: for this cross-sectional study, 133 informal caretakers of terminally-ill breast and gynecologic cancer patients were included. Patients were hospitalized for palliative care in the Oncology Clinic of the Centro de Atencao Integral a Saude da Mulher (Campinas, Brasil) from August 2002 to May 2004. Seventy-one of the patients had breast cancer and 62 had gynecological malignancies. Hospital Anxiety and Depression Scale (HAD) was applied to these informal caretakers, in order to detect anxiety and depression, and they were also interviewed to provide additional information regarding their age, gender, religion, relation to patient, current occupation, if they cared for other people, whether their routine had changed and whether other people helped them to care for the patient. Logistic regression was used to calculate the odds ratio (OR) and its confidence interval (CI), used to assess the relationship between the diagnoses of anxiety and depression among the informal caretakers. For multiple analyses, the stepwise criterion for variable selection was used. RESULTS: 43% percent of the patients identified their daughters as their main caretaker, and 24%, their husbands. Most of the caretakers were over 35 years old (63%), 68% were female, 59% were unemployed, 47% cared for another person and 84% referred that his/her routine had changed because of caring. Anxiety was detected in 99 caretakers (74.4%) and depression in 71 (53.4%). Anxiety and depression were strongly correlated (odds ratio 5.6; 95% confidence interval 2.2 to 15.9). Bivariate analysis disclosed that the patients' husbands were less affected by depression, but multivariate analysis revealed that only the fact of being male was related to a lower prevalence of anxiety. CONCLUSION: caring for terminally-ill cancer patients led to high prevalence of anxiety and depression. Only men and the patients' husbands were found to have a lower prevalence of anxiety.

Influence of free testosterone on antigen levels of plasminogen activator inhibitor-1 in premonopausal women with central obesity

Women with upper body obesity are at increased risk for cardiovascular disease (CVD). Several studies have demonstrated a reduced fibrinolytic activity in these patients, mainly due to an enhanced activity of plasminogen activator inhibitor-1 (PAI-1). Since an increase of androgenic activity is a feature of central obesity in women, the present study was aimed at evaluating the possibility of a relationship between androgens and PAI-1 (antigen and activity) in 20 premenopausal women, 10 with upper body obesity and 10 controls. In obese women, PAI-1 antigen showed a positive Pearson correlation with free testosterone (FT), insulin, c-peptide, triglycerides (TG), and waist to hip ratio (WHR) ( P < .01), whereas PAI-1 activity correlated positively only with insulin and WHR ( P < .01). In control women, PAI-1 antigen and activity were positively related only to TG ( P < .01). When we applied the multiple regression model with stepwise backward method to our data, both PAI-1 antigen and activity did not maintain any significant association. However, when the data from both the groups were pooled (n = 20), and PAI-1 antigen was considered as the dependent variable, body weight (Sig T = 0.0001), TG (Sig T = 0.0053), FT (Sig T = 0.013), and luteinizing hormone (LH) (Sig T = 0.0474) met the stepwise criteria, suggesting an independent effect of each of these parameters on PAI-1 antigen. On the other hand, when PAI-1 activity was tested as the dependent variable, only body weight maintained a significant relationship with this parameter (Sig T = 0.0006). Therefore, although our findings only represent a preliminary study, they seem to suggest that FT independently influences the circulating levels of PAI-1 antigen. This mechanism may represent a possible link between increased androgenic activity and cardiovascular risk in women with upper body obesity.

Hierarchy in picture segmentation: a stepwise optimization approach

A segmentation algorithm based on sequential optimization which produces a hierarchical decomposition of the picture is presented. The decomposition is data driven with no restriction on segment shapes. It can be viewed as a tree, where the nodes correspond to picture segments and where links between nodes indicate set inclusions. Picture segmentation is first regarded as a problem of piecewise picture approximation, which consists of finding the partition with the minimum approximation error. Then, picture segmentation is presented as an hypothesis-testing process which merges only segments that belong to the same region. A hierarchical decomposition constraint is used in both cases, which results in the same stepwise optimization algorithm. At each iteration, the two most similar segments are merged by optimizing a stepwise criterion. The algorithm is used to segment a remote-sensing picture, and illustrate the hierarchical structure of the picture.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>