Improved estimation of human cortical activity and connectivity with the multimodal integration of neuroelectric and hemodynamic data

In the last decade, the possibility to noninvasively estimate cortical activity and connectivity has been highlighted by the application of the techniques known as high resolution EEG. These techniques include a subject's multi-compartment head model (scalp, skull, dura mater, cortex) constructed from individual magnetic resonance images, multi-dipole source model, and regularized linear inverse source estimates of cortical current density. More recently, it has proved as the use of information from the hemodynamic responses of the cortical areas as revealed by block-designed (strength of activated voxels) fMRI improves dramatically the estimates of cortical activity and connectivity. Here, we present some applications of such estimation in two set of high resolution EEG and fMRI data, related to the motor (finger tapping) and cognitive (Stroop) tasks. We observed that the proposed technology was able to unveil the direction of the information flow between the cortical regions of interest.

Estrous cycle characterisation and artificial insemination using frozen–thawed spermatozoa in the bottlenose dolphin (Tursiops truncatus)

The reproductive endocrinology of the bottlenose dolphin,Tursiops truncatus,was characterized to facilitate the development of artificial insemination using cryopreserved spermatozoa. Specific objectives were: (i) to determine the excretory dynamics of urinary luteinizing hormone (LH) and ovarian steroid metabolites during the estrous cycle; (ii) to evaluate the effect of an exogenously administered synthetic progesterone analog (altrenogest) on reproductive hormone excretion; (iii) to correlate follicular growth and ovulation (as determined by transabdominal ultrasound) to urinary LH and ovarian steroid metabolites; (iv) examine thein vivofertilisation capacity of cryopreserved semen, and (v) to develop an intrauterine insemination technique. Based on urinary endocrine monitoring of natural estrous cycles (2 consecutive cycles) and nine post altrenogest cycles in ten females, estrous cycles were found to be 36 days long and comprised of an 8 day and 19 day follicular and luteal phase, respectively. Peak estrogen conjugates (EC; 5.4 ± 3.8 ng/mg creatinine (Cr)) occurred 8 h prior to the LH surge (70.9 ± 115.7 ng/mg Cr). The time of ovulation, as determined by ultrasonography, occurred 32.1 ± 8.9 h and 24.3 ± 7.0 h after the onset of the LH surge and LH peak, respectively. Mean preovulatory follicular diameter and circumference were 2.1 ± 0.5 cm and 6.5 ± 1.5 cm, respectively. Of the 27 estrous synchronisation attempts, 13 resulted in an ovulatory cycle, with ovulation occurring 21 days post-altrenogest treatment. Intrauterine (4 of 5) and intracornual (1 of 3) inseminations conducted across eight estrous cycles resulted in five pregnancies (63%), one pregnancy resulted from the use of liquid stored semen, whereas four were achieved using cryopreserved semen. These data provide new information on female bottlenose dolphin reproductive physiology, and demonstrate that the combination of endocrine monitoring and serial ultrasonography contributed to successful AI using liquid-stored and cryopreserved semen.

Estimation of the cortical functional connectivity with the multimodal integration of high-resolution EEG and fMRI data by directed transfer function

Nowadays, several types of brain imaging device are available to provide images of the functional activity of the cerebral cortex based on hemodynamic, metabolic, or electromagnetic measurements. However, static images of brain regions activated during particular tasks do not convey the information of how these regions communicate with each other. In this study, advanced methods for the estimation of cortical connectivity from combined high-resolution electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) data are presented. These methods include a subject's multicompartment head model (scalp, skull, dura mater, cortex) constructed from individual magnetic resonance images, multidipole source model, and regularized linear inverse source estimates of cortical current density. Determination of the priors in the resolution of the linear inverse problem was performed with the use of information from the hemodynamic responses of the cortical areas as revealed by block-designed (strength of activated voxels) fMRI. We estimate functional cortical connectivity by computing the directed transfer function (DTF) on the estimated cortical current density waveforms in regions of interest (ROIs) on the modeled cortical mantle. The proposed method was able to unveil the direction of the information flow between the cortical regions of interest, as it is directional in nature. Furthermore, this method allows to detect changes in the time course of information flow between cortical regions in different frequency bands. The reliability of these techniques was further demonstrated by elaboration of high-resolution EEG and fMRI signals collected during visually triggered finger movements in four healthy subjects. Connectivity patterns estimated for this task reveal an involvement of right parietal and bilateral premotor and prefrontal cortical areas. This cortical region involvement resembles that revealed in previous studies where visually triggered finger movements were analyzed with the use of separate EEG or fMRI measurements.

Theoretical and finite-element investigation of the mechanical response of spinodal structures

In recent years there have been major advances in our understanding of the mechanisms of phase separation in polymer and copolymer blends, to the extent that good control of phase-separated morphology is a real possibility. Many groups are studying the computational simulation of polymer phase separation. In the light of this, we are exploring methods which will give insight into the mechanical response of multiphase polymers. We present preliminary results from a process which allows the production of a two-dimensional finite-element mesh from the contouring of simulated composition data. We examine the stretching of two-phase structures obtained from a simulation of linear Cahn-Hilliard spinodal phase separation. In the simulations, we assume one phase to be hard, and the other soft, such that the shear modulus ratio G is large (>or= 10(3)). We indicate the effect of varying composition on the material modulus and on the distribution of strains through the stretched material. We also examine in some detail the symmetric structures obtained at 50% composition, in which both phases are at a percolation threshold. Inspired by simulation results for the deformation of these structures, we construct a "scaling" theory, which reproduces the main features of the deformation. Of particular interest is the emergence of a lengthscale, below which the deformation is non-affine. This length is proportional to G(1/4), and hence is still quite small for all reasonable values of this ratio. The same theory predicts that the effective composite modulus scales also as G(1/4), , which is supported by the simulations.

Mindful messages: surfing for spirituality

As it becomes clearer that spiritual concerns are very much part of the work of palliative care nurses, it is interesting to note the many ways in which patients express their needs and the different approaches adopted by carers in addressing them. This site, although not specific to palliative care, reflects many concerns familiar to those working with people whose illness may focus their thoughts on death or dying either at diagnosis, or as a longer-term source of distress.

Interpretations and variations of ISO 9000 in acute health care. International Organization for Standardization

OBJECTIVE

This paper aims to address two questions related to the implementation of the ISO 9000 Quality Management System standard in the acute health care sector: which countries have developed specific nationwide guidelines/interpretations? and what variances exist between the different interpretations of the ISO 9002 standard?

DESIGN

The study was carried out via an assessment of the available guideline documents for the use of ISO 9000 in the acute health care sector. The interpretation of each document was examined for common elements and deviations from the commonly agreed terms.

SETTING

Worldwide in the acute health care sector (excluding that of laboratories).

STUDY PARTICIPANTS

Eighty-two international ISO members and/or quality health care organizations.

RESULTS

The results showed variation in the interpretations of the ISO 9000 standard. In total, 16 of the clauses/subclauses note distinct variations, between one or more of the documents, which could alter the perception of the system.

CONCLUSION

From examination of the six identified guideline documents, the claim that ISO 9000 introduces quality systems which are comparable from one country to another is unfounded in the acute health care sector.

Male cancers: the great taboo

Linked as they are with taboos on age, sex and continence, it is perhaps no surprise that male cancers have not received the same exposure as, for instance, breast cancer. This is also the case on the Internet, which is often criticized for its male dominance. However, a growing number of efforts are being made to redress this balance.

Three words three shapes: A clinical test of memory

Three Words - Three Shapes was designed as an easy "bedside" test for elderly patients that assesses verbal and nonverbal memory within the same modality. In the present study, it was administered to patients with probable Alzheimer's disease (PRAD), a control group of non-demented older subjects (NC) and a group of patients with Korsakoff's amnesia (KA). Incidental recall and several other measures of learning, retention and recognition differentiated control from PRAD and KA subjects. PRAD and KA subjects' performance was similar, but there were some material-specific interactions. This test is relatively easy and some of the derived measures could prove useful in staging amnesia progression beyond the earliest stages of PRAD when more difficult tests yield floor effects.

Fatigue: online resources and advice

This site is a joint development by the Oncology Nursing Society and the Fatigue Coalition. Like many US sites, the content is also available in Spanish in order to reach the widest possible audience. The site allows the user to explore fatigue in detail, and includes information that patients may use to improve their ability to cope with this cancer symptom. For the professional, the site raises the challenge of considering fatigue in a new light; not just as an inevitable part of cancer, its treatment and progression but rather as a problem that needs to be addressed in a holistic fashion in much the same way as pain is.

Breast cancer: net gains for patients

Dominated by the pink ribbon logo now so clearly linked with breast cancer, this site offers a range of material and highlights the support services offered by this charity to the 1 in 11 women in the UK who develop the disease in any one year.

Paediatric palliative care comes of age

With its colourful layout and detailed explanations this site aims to raise the profile of children’s palliative care, which has emerged as a speciality in the last decade. Although some elements of this site remain under construction, if this area of nursing interests you then it is one for your hotlist.