Comparison of Spontaneous Pushing and Directed Pushing During the Second Stage of Labor Among Chinese Women Without Epidural Analgesia: Protocol for a Noninferior Feasibility Study

BACKGROUND

Maternal pushing during the second stage of labor could influence labor progress and maternal-neonatal outcomes. Although the image of health care providers directing the laboring women to push during the second stage of labor could be commonly observed globally, this practice is not sufficiently researched and is questioned regarding its effectiveness and outcomes on the mother and baby. Meanwhile, a strategy referred to as "spontaneous pushing," which supports women to push by following their bodily urges, has been evaluated in several trials. However, in China, spontaneous pushing is not common practice. Notwithstanding the evaluation of spontaneous pushing, there is a lack of high-quality evidence to support either strategies of directed pushing or spontaneous pushing.

OBJECTIVE

This study aims to test the feasibility of a future randomized controlled trial to compare the effects of spontaneous pushing and directed pushing during the second stage of labor for maternal and neonatal outcomes in China.

METHODS

A nonrandomized, single-group, noninferiority feasibility study will be conducted in a public hospital in Hebei Province, China. In total, 105 women meeting the selection criteria will be recruited to receive the intervention (spontaneous pushing), while 105 sets of medical notes from women who received routine care (directed pushing) will be identified and reviewed to compare outcomes for both cohorts. A mixed methods approach will be used to assess primary outcomes (feasibility and acceptability) and secondary outcomes (effectiveness).

RESULTS

Data collection took place between May and October 2023. A total of 110 women were invited to participate in the intervention of spontaneous pushing. Midwives' interviews were conducted and will be transcribed for analysis in March 2024. The data analysis is planned to be completed by May 2024.

CONCLUSIONS

This feasibility study will provide important information by conducting a full-scale clinical trial in the future as well as the potential facilitators and barriers of it. A future randomized controlled trial is likely to have considerable policy and funding impacts regarding pushing management during the second stage of labor and improvement in women's childbirth experience.

TRIAL REGISTRATION

Chinese Clinical Trial Register ChiCTR2300071178; https://tinyurl.com/mudtnbft.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/55701.

Content Analysis of #Postpartumbody Images Posted to Instagram

Understanding the imagery on social media targeting postpartum women is an important step in determining the utility of Instagram as a potential avenue for targeting public health messages to this group. This study (1) describes the content of images on Instagram tagged with #postpartumbody and; (2) compares images from ‘Top’ posts (‘trending’ or ‘popular’) with ‘Recent’ posts. 600 images tagged with #postpartumbody (300 ‘Top’ and 300 ‘Recent’) were systematically captured from Instagram and coded using a predefined framework. Images of women were coded for adiposity, muscularity, pose and attire. Chi-square tests were used to compare ‘Top’ and ‘Recent’ posts. Most (n = 409) images were of a woman who generally had low/average adiposity (91%) and little-to-none/some visible muscle definition (93%). Most women (52%) were posing in a non-specific manner, 5% were posing to accentuate a postpartum body feature and 40% were wearing fitness attire. Compared with ‘Recent’, ‘Top’ posts were less likely to be text-focused (p < 0.001), photos of food (p < 0.001) or linked to a product/program (p < 0.001). Women of lower adiposity are more likely to post images of themselves on Instagram tagged with #postpartumbody than women of higher adiposity, which may reflect increased body pride in this group, but could reduce body satisfaction for some viewers. Conveying health information on Instagram may be necessary to interrupt potentially harmful content.

Preferences of Australian healthcare providers regarding education on long-term health after hypertensive disorders of pregnancy: a qualitative study

OBJECTIVES

To explore Australian healthcare providers' (HCPs') preferred content, format and access to education regarding long-term health after hypertensive disorder of pregnancy (HDP), in order to guide the development of education programmes.

DESIGN AND SETTING

A qualitative study using a framework analysis was undertaken. Registered HCP who were practising in Australia and previously completed a survey about long-term health after HDP were invited to participate.

PARTICIPANTS

Twenty HCP were interviewed, including midwives, specialist obstetrician/gynaecologists, general practitioners with a diploma in obstetrics and gynaecology, and cardiologists.

PRIMARY AND SECONDARY OUTCOME MEASURES

Exploration of preferred content, format and distribution of educational material post-HDP.

RESULTS

Twenty HCP were interviewed in April to May 2020. Four main categories were identified. 'Obtaining evidence-based information for own learning' addressing own learning with preference for multi-disciplinary education, preferably endorsed or facilitated by professional organisations. 'Optimising the referral process from hospital to community health services' was about the need for structured long-term follow-up to transition from hospital to community health and align with HDP guidelines. 'Facilitating women's health literacy' addressed the need for evidence-based, print or web-based material to assist risk discussions with women. 'Seizing educational opportunities' addressed the responsibility of all HCP to identify education opportunities to initiate key health discussions with women.

CONCLUSIONS

HCP provided ideas on content, format and access of education regarding long-term health post-HDP within the parameters of the Australian healthcare context. This evidence will guide educational developments for HCP on post-HDP health to ensure they can better care for women and families.

Exploring education preferences of Australian women regarding long-term health after hypertensive disorders of pregnancy: a qualitative perspective

BACKGROUND

Hypertensive disorders of pregnancy (HDP) affect 5-10% of pregnant women. Long-term health issues for these women include 2-3 times the risk of heart attacks, stroke and diabetes, starting within 10 years after pregnancy, making long-term health after HDP of major public health importance. Recent studies suggest this knowledge is not being transferred sufficiently to women and how best to transmit this information is not known. This study explored women's preferred content, format and access to education regarding long-term health after HDP.

METHODS

This was a qualitative study and framework analysis was undertaken. Women with a history of HDP who had participated in a survey on long-term health after HDP were invited to participate in this study. During telephone interviews women were asked about preferences and priorities concerning knowledge acquisition around long-term health after HDP.

RESULTS

Thirteen women were interviewed. They indicated that they wanted more detailed information about long-term and modifiable risk factors. Their preference was to receive risk counselling from their healthcare provider (HCP) early after giving birth along with evidence-based, print or web-based information to take home. All women suggested more structured postnatal follow-up, with automated reminders for key appointments. Automated reminders should detail rationale for follow-up, recommended tests and discussion topics to be addressed at the appointment.

CONCLUSION

Our findings show that most participants wanted information soon after birth with all women wanting information within 12 months post birth, complemented with detailed take-home evidence. Participants indicated preference for structured follow-up via their HCP with automated alerts about the appointment and recommended tests. This evidence can be used to guide the development of education programs for women on health after HDP which may enhance knowledge, preventive health management and more generally improve women's health trajectories.

Assessing Australian women's knowledge and knowledge preferences about long-term health after hypertensive disorders of pregnancy: a survey study

OBJECTIVES

To (1) assess women's current knowledge regarding long-term cardiovascular health after hypertensive disorders of pregnancy (2) elicit women's preferred educational content and format regarding health after hypertensive disorders of pregnancy.

DESIGN AND SETTING

A custom-created online survey exploring Australian women's knowledge about long-term health after hypertensive disorders of pregnancy, distributed through consumer groups and social media.

PARTICIPANTS

266 women with (n=174) or without (n=92) a history of hypertensive disorders of pregnancy. PRIMARY AND SECONDARY OUTCOME MEASURES: (1) Proportion of women identifying long-term health risks after hypertensive disorder of pregnancy using a 10-point risk knowledge score with 0-4 'low', 4.1-7.0 'moderate' and 7.1-10 'high'. (2) Exploration of preferred content, format and distribution of educational material post hypertensive disorder of pregnancy.

RESULTS

Knowledge scores about health after hypertensive disorder of pregnancy were moderate in groups with and without a history of the disorder. Knowledge was highest regarding risk of recurrent hypertensive disorders in a subsequent pregnancy, 'moderate' for chronic hypertension and heart attack, 'moderate' and 'low' regarding risk of heart disease and 'low' for diabetes and renal disease. Only 36% of all participants were aware that risks start within 10 years after the affected pregnancy. The majority of respondents with a history of hypertensive disorder of pregnancy (76%) preferred receiving information about long-term health 0-6 months post partum from a healthcare provider (80%), key organisations (60%), social media (47%) and brochures/flyers (43%).

CONCLUSIONS

Women's knowledge regarding health risks after hypertensive disorder of pregnancy was 'moderate', although with important disease-specific gaps such as increased risk of diabetes. Most women wanted to be informed about their long-term health from a healthcare provider.

Assessing knowledge of healthcare providers concerning cardiovascular risk after hypertensive disorders of pregnancy: an Australian national survey

BACKGROUND

Hypertensive disorders of pregnancy (HDP) affect 5-10% of pregnant women. Women after HDP have 2-3 times increased risk of heart attack, stroke and diabetes, as soon as 5-10 years after pregnancy. Australian healthcare providers' knowledge of cardiovascular disease (CVD) risks for women after HDP is unknown, and this study aimed to explore their current knowledge and practice regarding long-term cardiovascular health after HDP, as a precursor to producing targeted healthcare provider education on health after HDP.

METHODS

A custom-created, face-validated online survey explored knowledge about long-term risks after HDP. Distribution occurred from February to July 2019 via professional colleges, key organisations and social media. The objective was to assess current knowledge and knowledge gaps amongst a group of healthcare providers (HCP) in Australia, regarding long-term cardiovascular health after hypertensive disorders of pregnancy (HDP), specifically gestational hypertension or preeclampsia.

RESULTS

Of 492 respondents, 203 were midwives, 188 obstetricians, 75 general practitioners (GP), and 26 cardiologists. A risk knowledge score was computed with 0-6 considered low, 6.1-8.9 moderate and 9-12 high. Most participants (85%) were aware of increased cardiovascular disease after preeclampsia and gestational hypertension (range 76% midwives to 100% cardiologists). There were significant differences in average knowledge scores regarding health after preeclampsia; high for cardiologists (9.3), moderate for GPs and obstetricians (8.2 and 7.6 respectively) and low for midwives (5.9). Average knowledge scores were somewhat lower for gestational hypertension (9.0 for cardiologists, 7.4 for obstetricians and GPs, 5.1 for midwives). Knowledge was highest regarding risk of chronic hypertension, moderate to high regarding risk of ischaemic heart disease, stroke and recurring HDP, and low for diabetes and peripheral vascular disease. Only 34% were aware that risks start < 10 years after the affected pregnancy.

CONCLUSION(S)

Participants were aware there is increased cardiovascular risk after HDP, although less aware of risks after gestational hypertension and some specific risks including diabetes. Findings will inform the development of targeted education.

Assessing Knowledge Gaps of Women and Healthcare Providers Concerning Cardiovascular Risk After Hypertensive Disorders of Pregnancy-A Scoping Review

Background: A history of a Hypertensive Disorder of Pregnancy (HDP) at least doubles a woman's risk of cardiovascular disease (CVD). The risk increases within 10 years after HDP and continues for life, making long-term health after HDP of major public health importance. Understanding knowledge gaps in health care professionals and women regarding cardiovascular health after HDP is an important component in addressing these risks.

Objectives: The primary aim was to examine what women and healthcare providers (HCP) know about cardiovascular risks after HDP. The secondary aims were to identify enablers and barriers to knowledge and action on knowledge.

Methods: A scoping review was conducted. This was a narrative synthesis, using PRISMA-ScR guidelines, of English-language full text articles that included assessment of knowledge of women, and/or HCP, on long term cardiovascular risk after HDP. The databases Embase, Medline, Scopus, ProQuest, Cochrane, and PsycInfo were searched from 01 January 2005 to 31 May 2019.

Results: Twelve studies were included, six addressing women's knowledge, five addressing HCP knowledge, and one addressing both. The studies included 402 women and 1,215 HCP from seven countries. Regarding women's knowledge, six of seven studies found women had limited or no knowledge about the link between HDP and CVD. Where women were aware of the link, the majority had sourced their own information, rather than obtaining it through their HCP. In five of six studies, HCP also mostly had limited knowledge about HDP-CVD links. Primary enablers for HCP acquisition of knowledge and counseling were the availability and knowledge of guidelines. Where comparisons between HCP groups were made, obstetricians had greater knowledge than family physicians, internal medical specialists, or midwives.

Conclusion: There was a low level of knowledge amongst HCP and women about increased CVD risk after HDP. Where women had higher levels of knowledge, the information was often obtained informally rather than from HCP. There were variations in knowledge of HCP, with obstetricians generally more aware than other professions. Further country and context-specific research on current status of women's and HCP's knowledge is therefore necessary when creating educational strategies to address knowledge gaps after HDP.

Ventral rectopexy with biological mesh for recurrent disorders of the posterior pelvic organ compartment

PURPOSE

Recurrent prolapse of the posterior pelvic organ compartment presents a management challenge, with the best surgical procedure remaining unclear. We present functional outcome and patient satisfaction after laparoscopic and robotic ventral mesh rectopexy (VMR) with biological mesh in patients with recurrence.

METHODS

We analyzed data from 30 patients with recurrent posterior pelvic organ prolapse who underwent VMR with biological mesh from August 2012 to January 2018. Data included patient demographics and intra- and postoperative findings; functional outcome as assessed by Cleveland Clinic Constipation Score (CCCS), Obstructed Defecation Score Longo (ODS), and Cleveland Clinic Incontinence Score (CCIS); and patient satisfaction.

RESULTS

CCCS, CCIS, and ODS were significantly improved at 6-12 months postoperatively and at last follow-up. Patient satisfaction (visual analog scale [VAS] 6.7 [0 to 10]), subjective symptoms (+ 3.4 [scale - 5 to + 5]), and quality of life improvement (+ 3.0 [scale from - 5 to + 5]) were high at last follow-up. The rates of morbidity and major complications were 13% and 3%, respectively. There were no mesh-related complications or deaths. Difference in type of previous surgery (abdominal or transanal/perineal) had no significant effect on results.

CONCLUSIONS

VMR with biological mesh is a safe and effective option for patients with recurrent posterior pelvic organ prolapse. It reduces functional symptoms, has a low complication rate, and promotes patient satisfaction.

Ate1-mediated posttranslational arginylation affects substrate adhesion and cell migration in Dictyostelium discoideum

The highly conserved enzyme arginyl-tRNA-protein transferase (Ate1) mediates arginylation, a posttranslational modification that is only incompletely understood at its molecular level. To investigate whether arginylation affects actin-dependent processes in a simple model organism, Dictyostelium discoideum, we knocked out the gene encoding Ate1 and characterized the phenotype of ate1-null cells. Visualization of actin cytoskeleton dynamics by live-cell microscopy indicated significant changes in comparison to wild-type cells. Ate1-null cells were almost completely lacking focal actin adhesion sites at the substrate-attached surface and were only weakly adhesive. In two-dimensional chemotaxis assays toward folate or cAMP, the motility of ate1-null cells was increased. However, in three-dimensional chemotaxis involving more confined conditions, the motility of ate1-null cells was significantly reduced. Live-cell imaging showed that GFP-tagged Ate1 rapidly relocates to sites of newly formed actin-rich protrusions. By mass spectrometric analysis, we identified four arginylation sites in the most abundant actin isoform of Dictyostelium, in addition to arginylation sites in other actin isoforms and several actin-binding proteins. In vitro polymerization assays with actin purified from ate1-null cells revealed a diminished polymerization capacity in comparison to wild-type actin. Our data indicate that arginylation plays a crucial role in the regulation of cytoskeletal activities.

Filamin A promotes efficient migration and phagocytosis of neutrophil-like HL-60 cells

The primary defense machinery to combat inflammation involves neutrophil granulocytes which in order to execute their functions rely on the efficiency of different cellular mechanisms including adhesion, spreading, migration in different environments, and phagocytosis. These functions require an accurately regulated actin network as well as the activation and adjustment of various signaling pathways. Mammalian filamins (FLNs) comprise three highly homologous large actin-binding proteins that are obvious candidates to control these processes as FLNs have been described to play a role in migration, spreading and adhesion in a variety of different cell types. The present study analyzed the role of filamin A (FLNa) in human neutrophil-like HL-60 cells. We found a strong enrichment of FLNa at the uropod of migrating neutrophils, and show that deficiency of FLNa caused a decrease in speed of migration both in 2D and 3D that is accompanied by a reduced activation of myosin-II. In addition, we show that FLNa plays a role in neutrophil phagocytosis. We also identified a hitherto unknown interaction of FLNa with coronin 1A that is mediated by FLNa repeats 9-18. FLNa deficiency had no or only minor effects on cell adhesion and spreading. In summary, deficiency of FLNa in human neutrophil-like HL-60 cells resulted in a surprisingly subtle phenotype. Our data indicate that FLNa is not essential for the regulation of mechanical properties during migration, but contributes to motility in a modulatory manner probably through its action at the uropod.

Balanced cortical stiffness is important for efficient migration of Dictyostelium cells in confined environments

Dictyostelium discoideum cells resemble in many aspects human leukocytes and serve as a model to study actin cytoskeleton dynamics and cell migration of highly motile cells. Dictyostelium cells deficient in the actin-binding protein filamin (ddFLN) showed a surprisingly subtle change in phenotype with no or only minor effects in single cell motility. These findings were in contrast to the strong actin-crosslinking activities measured for filamin in vitro. In the present study, we set out to revisit the role of ddFLN in cell migration. For this purpose, we examined migration of wild-type, ddFLN-null and ddFLN-overexpressing cells under different conditions. In addition to cyclic-AMP chemotaxis assays using micropipettes, we explored cell migration under more confined conditions: an under-agarose 2D assay and a 3D assay employing a collagen matrix that was adapted from assays for leukocytes. Using 3D migration conditions, cells deficient in ddFLN displayed only a minor impairment of motility, similar to the results obtained for migration in 2D. However, cells overexpressing ddFLN showed a remarkable decrease in the speed of migration in particular in 3D environments. We suggest that these results are in line with an increased stiffening of the cortex due to the crosslinking activity of overexpressed ddFLN. Our conclusion is that the absolute level of ddFLN is critical for efficient migration. Furthermore, our results show that under conditions of increased mechanical stress, Dictyostelium cells, like leukocytes, switch to a bleb-based mode of movement.

Spin-Orbital Excitation Continuum and Anomalous Electron-Phonon Interaction in the Mott Insulator LaTiO_{3}

Raman scattering experiments on stoichiometric, Mott-insulating LaTiO_{3} over a wide range of excitation energies reveal a broad electronic continuum which is featureless in the paramagnetic state, but develops a gap of ~800 cm^{-1} upon cooling below the Néel temperature T_{N}=146 K. In the antiferromagnetic state, the spectral weight below the gap is transferred to well-defined spectral features due to spin and orbital excitations. Low-energy phonons exhibit pronounced Fano anomalies indicative of strong interaction with the electron system for T>T_{N}, but become sharp and symmetric for T<T_{N}. The electronic continuum and the marked renormalization of the phonon lifetime by the onset of magnetic order are highly unusual for Mott insulators and indicate liquidlike correlations between spins and orbitals.

Nicotinic acid effects on insulin sensitivity and hepatic lipid metabolism: an in vivo to in vitro study

Our aim was to characterize the effects and the underlying mechanisms of the lipid-regulating agent Niaspan(®) on both insulin action and triglyceride decrease in 20 nondiabetic, dyslipidemic men with metabolic syndrome receiving Niaspan(®) (2 g/day) or placebo for 8 weeks in a randomized, cross-over study. The effects on plasma lipid profile were characterized at the beginning and the end of each treatment period; insulin sensitivity was assessed using the 2-step euglycemic hyperinsulinemic clamp and VLDL-triglyceride turnover by measuring plasma glycerol enrichment, both at the end of each treatment period. The mechanism of action of nicotinic acid was studied in HuH7 and mouse primary hepatocytes. Lipid profile was improved after Niaspan(®) treatment with a significant-28% decrease in triglyceride levels, a+17% increase in HDL-C concentration and unchanged levels of fasting nonesterified fatty acid. VLDL-tri-glyceride production rate was markedly reduced after Niaspan(®) (-68%). However, the treatment induced hepatic insulin resistance, as assessed by reduced inhibition of endogenous glucose production by insulin (0.7±0.4 vs. 1.0±0.5 mg/kg · min, p<0.05) and decrease in fasting hepatic insulin sensitivity index (4.8±1.8 vs. 3.2±1.6, p<0.05) in the Niaspan(®) condition. Nicotinic acid also reduced insulin action in HuH7 and primary hepatocytes, independently of the activation of hepatic PKCε. This effect was associated with an increase in diacylglycerol and a decrease in tri-glyceride contents that occurred in the absence of modification of DGAT2 expression and activity. Eight weeks of Niaspan(®) treatment in dyslipidemic patients with metabolic syndrome induce hepatic insulin resistance. The mechanism could involve an accumulation of diacylglycerol and an alteration of insulin signaling in hepatocytes.

Differential diagnosis of primary failure of eruption (PFE) with and without evidence of pathogenic mutations in the PTHR1 gene

BACKGROUND

Primary failure of eruption (PFE) may be associated with pathogenic mutations in the PTHR1 gene. It has numerous manifestations and is characterized by severe posterior open bite. However, there are also phenotypically similar types of eruption anomalies not associated with a known pathogenic PTHR1 mutation. The purpose of this study was to evaluate whether a distinction can be made between PTHR1-mutation carriers and noncarriers based on clinical and radiological findings.

PATIENTS AND METHODS

A total of 36 patients with suspected PFE diagnoses were included and analyzed in accordance with specific clinical and radiographic criteria. In addition, all patients underwent Sanger DNA sequencing analysis of all coding sequences (and the immediate flanking intronic sequences) of the PTHR1 gene.

RESULTS

Of these patients, 23 exhibited a heterozygous pathogenic mutation in the PTHR1 gene (PTHR1-mutation carriers), while molecular genetic analysis revealed nosequence alteration in the other 13 patients (non-PTHR1-mutation carriers). Relevant family histories were obtained from 5 patients in the carrier group; hence, this group included a total of 13 familial and 10 simplex cases. The group of noncarriers revealed no relevant family histories. All patients in the carrier group met six of the clinical and radiographic criteria explored in this study: (1) posterior teeth more often affected; (2) eruption disturbance of an anterior tooth in association with additional posterior-teeth involvement; (3) affected teeth resorbing the alveolar bone located coronal to them; (4) involvement of both deciduous and permanent teeth; (5) impaired vertical alveolar-process growth; and (6) severe subsequent finding of posterior open bite. None of the analyzed criteria were, by contrast, met by all patients in the noncarrier group. All patients in the carrier group could be assigned to one of three classifications indicating the extent of eruption disturbance, whereas 4 of the 13 noncarriers presented none of these three patterns. The clinical and radiographic criteria employed in this study would have correctly identified 10 of the 13 PFE patients in the noncarrier group as possessing no detectable PTHR1 mutation.

CONCLUSION

The evaluation of clinical and radiographic characteristics can heighten the specificity of ruling out suspected PTHR1 involvement in PFE patients. A hereditary element of PTHR1-associated PFE is clearly identifiable. More studies with more patients are needed to optimize the sensitivity of this preliminary approach on the differential identification of PTHR1-mutation carriers versus noncarriers by multivariate analysis.

Elemental topological insulator with tunable Fermi level: strained α-Sn on InSb(001)

We report on the epitaxial fabrication and electronic properties of a topological phase in strained α-Sn on InSb. The topological surface state forms in the presence of an unusual band order not based on direct spin-orbit coupling, as shown in density functional and GW slab-layer calculations. Angle-resolved photoemission including spin detection probes experimentally how the topological spin-polarized state emerges from the second bulk valence band. Moreover, we demonstrate the precise control of the Fermi level by dopants.

Instability Phenomena in Film Casting Process

This paper deals with instability phenomena in PET film casting. An experimental investigation makes it possible to confirm the occurrence of draw-resonance above a critical draw ratio, and to show interesting coupling effects between thickness and width fluctuations. A theoretical model is developed on the basis of some important assumptions: constant width, vertical film, isothermal regime and Newtonian behavior. It allows to calculate the response to a sudden increase of the chill roll velocity and to predict the critical draw ratio (DR = 20.3). Other types of perturbations of the roll velocity (sinusoidal oscillation, random fluctuations) are also treated using this model.

Validity of combining heart rate and uniaxial acceleration to measure free-living physical activity energy expenditure in young men

Combining accelerometry (ACC) with heart rate (HR) monitoring is thought to improve activity energy expenditure (AEE) estimations compared with ACC alone to evaluate the validity of ACC and HR used alone or combined. The purpose of this study was to estimate AEE in free-living conditions compared with doubly labeled water (DLW). Ten-day free-living AEE was measured by a DLW protocol in 35 18- to 55-yr-old men (11 lean active; 12 lean sedentary; 12 overweight sedentary) wearing an Actiheart (combining ACC and HR) and a RT3 accelerometer. AEE was estimated using group or individual calibration of the HR/AEE relationship, based on an exercise-tolerance test. In a subset (n = 21), AEE changes (ΔAEE) were measured after 1 mo of detraining (active subjects) or an 8-wk training (sedentary subjects). Actiheart-combined ACC/HR estimates were more accurate than estimates from HR or ACC alone. Accuracy of the Actiheart group-calibrated ACC/HR estimates was modest [intraclass correlation coefficient (ICC) = 0.62], with no bias but high root mean square error (RMSE) and limits of agreement (LOA). The mean bias of the estimates was reduced by one-third, like RMSE and LOA, by individual calibration (ICC = 0.81). Contrasting with group-calibrated estimates, the Actiheart individual-calibrated ACC/HR estimates explained 40% of the variance of the DLW-ΔAEE (ICC = 0.63). This study supports a good level of agreement between the Actiheart ACC/HR estimates and DLW-measured AEE in lean and overweight men with varying fitness levels. Individual calibration of the HR/AEE relationship is necessary for AEE estimations at an individual level rather than at group scale and for ΔAEE evaluation.

WE-E-213CD-03: Inverse-Consistent Symmetric Registration of Inner Colon Surfaces Derived from Prone and Supine CT Colonography

PURPOSE

Robust registration of prone and supine colonie surfaces acquired during CT colonography may lead to faster and more accurate detection of colorectal cancer and polyps. Any directional bias when registering one surface to the other could precipitate incorrect anatomical correspondence and engender reader error. Despite this, non-rigid registration methods are often implemented asymmetrically, which could negatively influence the registration. We aimed to reduce directional bias and so increase robustness by adapting a cylindrical registration algorithm to be both symmetric and inverse-consistent.

METHODS

The registration task can be simplified by mapping both prone and supine colonie surfaces onto regular cylinders. Spatial correspondence can then be established in cylindrical space using the original surfaces' local shape indices. We implemented a symmetric formulation of the popular non-rigid B-spline image registration method in cylindrical space. A symmetric similarity measure computes the sum of squared differences between both cylindrical representations of prone-to-supine and supine-to-prone directions simultaneously. Inverse consistency of the transformation is enforced by adding an appropriately weighted penalty term to the optimisation function.

RESULTS

We selected 8 CT colonography patient cases with marked variation in luminal distension and surface morphology. We randomly allocated 4 of these for tuning an optimal set of registration parameters and 4 for validation. The mean inverse-consistency error was reduced by 32% from 4.8mm to 3.2mm by the new symmetric formulation. The mean registration error improved from 8.2mm to 7.3mm for 330 manually chosen reference points on the 4 validation sets.

CONCLUSIONS

A symmetric formulation of prone and supine surface registration improves the quality of registration. Information from both prone-to-supine and supine-to-prone directions helps enforce convergence towards a more accurate solution due to reduced directional bias. A more robust and accurate registration will facilitate interpretation of CT colonography and has the potential to improve existing computer-aided detection methods. The authors gratefully acknowledge financial support for this work from the NIHR program: “Imaging diagnosis of colorectal cancer: Interventions for efficient and acceptable diagnosis in symptomatic and screening populationsâ€.

Transforming neurorehabilitation of walking following stroke: the promise of non-invasive brain stimulation--a review

PURPOSE

This narrative review discusses the neurophysiology of human motor cortex as it influences gait, and recent advances in the application of non-invasive brain stimulation to the lower limb motor cortex of stroke survivors. Although walking is a high priority following stroke, the efficacy of promising new therapies has yet to warrant their widespread clinical use. For the upper limb, numerous brain stimulation protocols have been described. These protocols, adapted for the leg, are now being used to examine the cortical control of gait. This research discounts the long-held notion that "we walk from our spinal cords".

METHODS

Our review describes this research as it relates to the lower limb, especially the use of non-invasive brain stimulation to enhance neuroplasticity. The review also discusses the possible development of a prognostic algorithm for walking recovery after stroke.

CONCLUSION

This review concludes with the expectation that novel brain stimulation protocols combined with therapy will eventually demonstrate a level of effectiveness sufficient to promote their wide acceptance in neurorehabilitation settings.

Momentum dependence of orbital excitations in Mott-insulating titanates

High-resolution resonant inelastic x-ray scattering has been used to determine the momentum dependence of orbital excitations in Mott-insulating LaTiO(3) and YTiO(3) over a wide range of the Brillouin zone. The data are compared to calculations in the framework of lattice-driven and superexchange-driven orbital ordering models. A superexchange model in which the experimentally observed modes are attributed to two-orbiton excitations yields the best description of the data.