Group living has been proposed to yield benefits that enhance fitness above the level that would be achieved through living as solitary individuals. Dominance hierarchies occur commonly in these social assemblages, and result, by definition, in resources not being evenly distributed between group members. Determinants of rank within a dominance hierarchy can be associated with morphological characteristics, previous experience of the individual, or personality traits such as exploration tendencies. The purpose of this study was to investigate whether greater exploration and positive responses to novel objects in homing pigeons (Columba livia) measured under laboratory conditions were associated with (i) greater initial exploration of the local area around the home loft during spontaneous exploration flights (SEF), (ii) faster and more efficient homing flights when released from further afield, and (iii) whether the traits of greater exploration and more positive responses to novel objects were more likely to be exhibited by the more dominant individuals within the group. There was no relationship between laboratory-based novel object exploration and position within the dominance hierarchy. Pigeons that were neophobic under laboratory conditions did not explore the local area during SEF opportunities. When released from sites further from home, neophobic pigeons took longer routes to home compared to those birds that had not exhibited neophobic traits under laboratory conditions, and had spontaneously explored to a greater extent. The lack of exploration in the neophobic birds is likely to have resulted in the increased costs of homing following release: unfamiliarity with the landscape likely led to the greater distances travelled and less efficient routes taken. Birds that demonstrated a lack of neophobia were not the dominant individuals inside the loft, and thus would have less access to resources such as food and potentially mates. However, a lack of neophobia makes the subordinate position possible, because subordinate birds that incur high travel costs would become calorie restricted and lose condition. Our results address emerging questions linking individual variation in behaviour with energetics and fitness consequences.This article is part of the themed issue 'Physiological determinants of social behaviour in animals'.

Objective: The study aimed to examine the association between socioeconomic factors (SEFs) and oral anticoagulation (OAC) therapy and whether it was influenced by changing guidelines. We hypothesised that inequities in initiation of OAC reduced over time as more detailed and explicit clinical guidelines were issued.

Design: Register-based observational study.

Settings: All Danish patients with an incident hospital diagnosis of atrial fibrillation (AF), aged ≥30 years old and with high risk of stroke from 1 May 1999 to 2 October 2015 were included. Absolute risk differences (RD) (95% CI) were used to measure the association.

Participants: 154 448 patients (mean age 78.2 years, men 47.3%).

Exposure: Education, family income and cohabiting status were the SEFs used as exposure.

Outcome: A prescription of OAC within -30 to +90 days of baseline (incident AF).

Results: During 2002-2007, the crude RD of initiation of OAC for men with high education was 14.9% (12.8 to 16.9). Inequality reduced when new guidelines were published, and in 2013-2016 the crude RD was 5.6% (3.5 to 7.7). After adjusting for age, the RD substantially reduced. The same pattern was seen for cohabiting status, while inequality was smaller and more constant for income.

Conclusion: Patients with low income, low education and living alone were associated with lower chance of being initiated with OAC. For education and cohabiting status, the crude difference reduced around 2011, when more detailed clinical guidelines were implemented in Denmark. Our results indicate that new guidelines might reduce inequality in OAC initiation and that new, high-cost drugs increase inequality.

Keywords: cardiology; social medicine; stroke; thromboembolism.

Visual search is coordinated adaptively by monitoring and predicting the environment. The supplementary eye field (SEF) plays a role in oculomotor control and outcome evaluation. However, it is not clear whether the SEF is involved in adjusting behavioral modes based on preceding feedback. We hypothesized that the SEF drives exploration-exploitation transitions by generating "surprise signals" or rectified prediction errors, which reflect differences between predicted and actual outcomes. To test this hypothesis, we introduced an oculomotor two-target search task in which monkeys were required to find two valid targets among four identical stimuli. After they detected the valid targets, they exploited their knowledge of target locations to obtain a reward by choosing the two valid targets alternately. Behavioral analysis revealed two distinct types of oculomotor search patterns: exploration and exploitation. We found that two types of SEF neurons represented the surprise signals. The error-surprise neurons showed enhanced activity when the monkey received the first error feedback after the target pair change, and this activity was followed by an exploratory oculomotor search pattern. The correct-surprise neurons showed enhanced activity when the monkey received the first correct feedback after an error trial, and this increased activity was followed by an exploitative, fixed-type search pattern. Our findings suggest that error-surprise neurons are involved in the transition from exploitation to exploration and that correct-surprise neurons are involved in the transition from exploration to exploitation.

A fully automated analytical methodology combining salting-out assisted liquid-liquid extraction (SALLE) and capillary electrophoresis (CE) for the analysis of three Tyrosine Kinase Inhibitors (TKIs) in plasma samples is proposed. The automated methodology, called A-SALLE-CE-UV, makes full use of the advantages of both techniques by combining desalting, protein precipitation, automated liquid-liquid extraction, in-line CE stacking and electrophoretic separation of analytes in plasma samples in a fully integrated way. At first, the capillary is used to deliver appropriate micro-volumes of extraction agent solutions (acetonitrile, salt) in the plasma sample. ACN and salting-out agent (NaCl) solutions are added by pressure from outlet vials into the sample vial (inlet) containing human plasma sample spiked with the three tested TKIs. After addition of both ACN and NaCl solutions, mixing is achieved by generating air bubbles leading to a two phases separation and extraction of TKIs in the upper mostly organic phase (ACN). The upper phase containing the TKIs is then injected and analysed by CE-UV. Due to the presence of ACN, the analytes are stacked in-line and successfully separated in the same capillary. The results obtained in terms of limit of detection (LOD), limit of quantification (LOQ), sensitivity enhancement factor (SEF), repeatability and linearity demonstrate the applicability of the proposed method for possible therapeutic drug monitoring (TDM) of TKIs.

To further validate the potential of functional magnetic resonance imaging (fMRI) for localization of the sensorimotor cortex, fMRI was compared with somatosensory evoked fields (SEFs) in eight normal volunteers. A conventional 1.5 T MRI scanner and an MRI-linked 66-channel whole head magnetoencephalography system were used. fMRI activated by unilateral hand squeeze movement indicated the highest activation on the central sulci that were localized by SEFs in all 16 contralateral hemispheres. This indicates that although the fMRI signal activation may originate from a vein running along the central sulcus, fMRI is reliable to detect the central sulcus. The pre-central gyrus also indicated some signal activation on fMRI implying better visualization of spatial distribution of activation. fMRI and SEFs are complementary methods for localizing the central sulcus.

Bioaerosols consisting of biologically originated airborne particles such as microbes, metabolites, toxins and fragments of microorganisms are present ubiquitously in our living environment. The international interests in bioaerosols have rapidly increased due to their many potential health effects. Thus, accurate and fast detection of total bioaerosols in different environments has become an important task for safeguarding against biological threats and broadening the pool of bioaerosol knowledge. To quickly evaluate the total bioaerosols concentration, we developed a localized surface plasmon resonance (LSPR) biosensor based on succinimidyl-ester-functionalized gold nanoislands (SEF-AuNIs) for quantitative bioaerosols detection. The detection limit of our proposed SEF-AuNIs sensors for model bacteria E. coli and B. subtilis can go to 0.5119 cells/ml and 1.69 cells/ml respectively. To demonstrate the capability of this bioaerosols sensing technique, we tested aerosol samples collected from Bern (urban station), Basel (suburban station) and Rigi mountain (rural and high altitude station) in Switzerland, and further investigated the correlation with endotoxin and PM10. The results substantiated that our SEF-AuNIs sensors could be a reliable candidate for total bioaerosols detection and air quality assessment.

We describe a method to apply large-area vibrotactile stimuli, based on a vibrating balloon, on the palms of both hands during evoked response studies. Magnetoencephalographic (MEG) signals were recorded with a whole-scalp neuromagnetometer from six healthy subjects while they held their hands on a balloon which was made to vibrate by delivering tones to it through a loudspeaker and a tube. The 200 Hz stimuli, presented once every 1 or 2 s in separate sessions, elicited prominent and replicable somatosensory evoked fields (SEFs) and also auditory evoked fields (AEFs) due to the concomitant sound. Source modelling allowed reliable differentiation between bilateral activation of the primary somatosensory (SI) cortices (peaks at 46-61 ms after the stimulus onset) and of the supratemporal auditory cortices (peaks at 104-126 ms). These simple vibrotactile stimuli could be useful for rapid and reliable identification of the somatosensory and auditory cortices, for example in presurgical evaluation of children.

Similar expression to FGF (Sef or IL17-RD), is a tumor suppressor and an inhibitor of growth factors as well as of pro-inflammatory cytokine signaling. In this study, we examined the regulation of Sef expression by gonadotropins during ovarian folliculogenesis. In sexually immature mice, in situ hybridization (ISH) localized Sef gene expression to early developing oocytes and granulosa cells (GC) but not to theca cells. Sef was also expressed in mouse ovarian endothelial cells, in the fallopian tube epithelium as well as in adipose tissue venules. SEF protein expression, determined by immunohistochemistry (IHC), correlated well with Sef mRNA expression in GC, while differential expression was noticed in oocytes. High Sef mRNA but undetectable SEF protein levels were observed in the oocytes of primary/secondary follicles, while an inverse correlation was found in the oocytes of preantral and small antral follicles. Sef mRNA expression dropped after pregnant mare's serum gonadotropin (PMSG) administration, peaked at 6-8 h after human chorionic gonadotropin (hCG) treatment, and declined by 12 h after this treatment. ISH and IHC localized the changes to oocytes and mural GC following PMSG treatment, whereas Sef expression increased in mural GC and declined in granulosa-lutein cells upon hCG treatment. The ovarian expression of SEF was confirmed using human samples. ISH localized SEF transcripts to human GC of antral follicles but not to corpora lutea. Furthermore, SEF mRNA was detected in human GC recovered from preovulatory follicles. These results are the first to demonstrate SEF expression in a healthy ovary during folliculogenesis. Hormonal regulation of its expression suggests that SEF may be an important factor involved in intra-ovarian control mechanisms.

The classical NF-κB transcription factor (RelA:p50) and the tumor suppressor Sef axis constitute a negative regulatory loop in which Sef, a target of NF-κB/RelA:p50, fine-tunes NF-κB/RelA:p50 transcriptional-activation in response to inflammatory stimuli trough binding to p50. Similar to the inhibitor IκBα, Sef sequesters NF-κB/RelA:p50 in the cytoplasm of unstimulated cells. Despite its key roles in regulating multiple cellular processes and its potential role as mediator between inflammation and cancer, Sef structural domains required to fulfill its tasks are poorly characterized, and how Sef specificity towards RelA:p50 is achieved is unknown. In-vitro binding assays using bacterially expressed Sef and Co-IP experiments, revealed that in addition to p50, Sef directly interacts with IκBα, and the IKKβ subunit of the IKK complex which mediates RelA:p50 induction by inflammatory stimuli. These interactions are ligand-independent and do not require Sef post-translational modifications. Deletion mutagenesis mapped binding site to IKKβ in a 74- residue segment juxtaposing Sef transmembrane domain, whereas several Sef regions seem to interact with IκBα. Moreover, we identified two new sites which together with the previously identified conserved tyrosine constitute three discontinuous Sef regions each indispensable for Sef binding to RelA:p50 and inhibiting its cytokine induced transcriptional activation. Contrary to IκBα, endogenous Sef is not degraded upon cytokine-stimulation, and its targeting in different cell types markedly enhances cytokine-induced NF-κB nuclear translocation. These results reveal Sef as the first scaffold that brings together the components of NF-κB/RelA:p50 signaling-module. Sef scaffolding function explains the basis for Sef specificity towards inhibiting inflammatory cytokine-induction of NF-κB/RelA:p50.

BACKGROUND

Fire smoke inhalation a recognized etiologic factor of airway injuries. The objective of this study was evaluation of serum high-mobility group box 1 (HMGB1) protein concentration in subjects exposed to fire smoke (SEFS).

METHODS

The study group consisted of 40 consecutive patients admitted to the Toxicology Unit, Lodz, Poland after exposure to fire smoke. Serum HMGB1 concentrations were measured upon admission to hospital and rechecked on the 2nd and on the day of discharge. Patients also underwent routine toxicological diagnostic procedures applied in case of those exposures, such as carboxyhaemoglobin (COHb) levels and urinary thiocyanate concentrations. The same diagnostic tests were performed in 10 healthy volunteers not exposed to smoke of the control group.

RESULTS

The average serum SEFS concentration of HMGB1 protein was not significantly higher on admission in comparison with the respective values recorded on the 2nd day and on the day of discharge. The mean serum level of HMGB1 protein of exposed group was higher than that one in the control group, however the difference was not statistically significant. The highest concentration of HMGB1 protein was noted in serum of 28 subjects exposed to fire smoke reporting at least one symptom and the difference was statistically significant in a comparison with the control group.

CONCLUSIONS

As indicated, an acute exposure to smoke may lead to transient increase of HMGB1 in serum in exposed subjects. Further studies are necessary in order to confirm the importance of this protein in pathogenesis of acute airway injury due to exposure to fire smoke.

In this paper, we present a new curvature-based three-dimensional (3-D) deformable surface model. The model deforms under defined force terms. Internal forces are calculated from local model curvature, using a robust method by a least-squares error (LSE) approximation to the Dupin indicatrix. External forces are calculated by applying a step expansion and restoration filter (SEF) to the image data. A solution for one of the most common problems associated with deformable models, self-cutting, has been proposed in this work. We use a principal axis analysis and reslicing of the deformable model, followed by triangulation of the slices, to remedy self-cutting. We use vertex resampling, multiresolution deformation, and refinement of the mesh grid to improve the quality of the model deformation, which leads to better results. Examples of the model application to different cases (simulation, magnetic resonance imaging (MRI), computerized tomography (CT), and ultrasound images) are presented, showing diversity and flexibility of the model.

OBJECTIVE

The objective of this retrospective study is to analyze whether preoperative functional imaging studies using FDG-PET and MEG enable prediction of postoperative seizure outcomes.

METHODS

Thirty-six patients with intractable temporal lobe epilepsy were studied. Asymmetry index of tCMRgluc (PET-AI) and the equivalent current dipole intensity of first response of SEF (SEF-AI) were determined preoperatively using (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET) and magnetoencephalography (MEG), respectively. Seizure outcomes were evaluated according to the classification proposed by the International League Against Epilepsy (ILAE) at least 24 months after resection of epileptic focuses. Twelve healthy volunteers were included in this study to determine the normal value.

RESULTS

Quantitative analysis revealed mean PET-AI in the patients was 5.4+/-5.2% (significantly different from normal controls); mean SEF-AI was 25.2+/-20.6% (not significantly different). PET-AI was positive (indicative of epileptic focus) in 29 of 36 patients (80.6%), while SEF-AI was positive in 17 of 36 patients (47.2%). Although no significant correlation between PET-AI and SEF-AI was noted (r=0.43), concordant asymmetry in both PET-AI and SEF-AI was significantly associated with better seizure outcome than discordant or paradoxical asymmetry of both factors (p<0.01).

CONCLUSIONS

The results suggest that quantitative analysis of tCMRgluc with SEF may be helpful in characterizing the preoperative epileptogenic condition and predicting postoperative seizure outcome in patients with temporal lobe epilepsy, although a constellation of developmental brain abnormalities and environmental factors that together produce epilepsy need to be further explored.

This study presents a method based on empirical mode decomposition (EMD) and a spatial template-based matching approach to extract sensorimotor oscillatory activities from multi-channel magnetoencephalographic (MEG) measurements during right index finger lifting. The longitudinal gradiometer of the sensor unit which presents most prominent SEF was selected on which each single-trial recording was decomposed into a set of intrinsic mode functions (IMFs). The correlation between each IMF of the selected channel and raw data on other channels were created and represented as a spatial map. The sensorimotor-related IMFs with corresponding correlational spatial map exhibiting large values on primary sensorimotor area (SMI) were selected via spatial-template matching process. Trial-specific alpha and beta bands were determined in sensorimotor-related oscillatory activities using a two-spectrum comparison between the spectra obtained from baseline period (-4 to -3 s) and movement-onset period (-0.5 to 0.5 s). Sensorimotor-related oscillatory activities were filtered within the trial-specific frequency bands to resolve task-related oscillatory activities. Results demonstrated that the optimal phase and amplitude information were preserved not only for alpha suppression (event-related desynchronization) and beta rebound (event-related synchronization) but also for profound analysis of subtle dynamics across trials. The retention of high SNR in the extracted oscillatory activities allow various methods of source estimation that can be applied to study the intricate brain dynamics of motor control mechanisms. The present study enables the possibility of investigating cortical pathophysiology of movement disorder on a trial-by-trial basis which also permits an effective alternative for participants or patients who can not endure lengthy procedures or are incapable of sustaining long experiments.

Burn injury is associated with major metabolic disturbances. Many factors or mediators are responsible for post-burn metabolic changes. The present study was designed to test the role of interstitial edema fluid from burn eschar in regulating amino acid transport into hepatic and muscle tissue. Subeschar tissue fluid (SEF) was collected from just under the full thickness burn area. Amino acid transport, determined as the uptake of [3H]-alpha-aminoisobutyric acid by incubated soleus muscles or liver slices in vitro, was reduced after the addition of subeschar tissue fluid. The suppression was more marked with fluids taken from patients with a large burn area. Significant findings were noted when the total surface burn area was more than 70%. There were significant differences in the SEF suppression effect between survivors and non-survivors, but not between inhalation and non-inhalation victims. The results suggest the presence of one or more factors in subeschar tissue fluid that inhibit both muscle and liver amino acid transport. The data also suggest that the inhibitory factors are most likely produced by the burned tissue. This suppression effect may be beneficial to burn victims in maintaining near-normal vascular osmolarity by way of an increased plasma amino acid level.

This study was designed to determine the relationship between the electroencephalogram (EEG) and clinical signs of depth of anaesthesia during induction of anaesthesia by slow infusion of propofol (18 mg/kg.h).

METHODS

Four groups of 12 patients each were studied (groups I and II: 18-50 years; groups III and IV:>> 70 years). Groups II and IV were given 0.15 mg fentanyl before the infusion of propofol was started. The clinical signs recorded were: (1) loss of eyelash reflex; (2) respiratory insufficiency; (3) tolerance to painful stimuli; and (4) intubation. Cardiovascular reactions were documented. The dosage was calculated from the infusion time (time from start of infusion until specific clinical event). Bipolar electrodes were placed at the C4/P4 positions (10-20 placement system) to record the EEG, which was processed by a personal computer (Narkograph) using fast-fourier transformation. The Narkograph calculates multiparametric EEG stages ranging from A to F (according to Kugler) as well as median frequency and spectral-edge frequency 95% (SEF). Stage A represents alpha rhythm, stage F is equivalent to a burst suppression pattern. For statistical analysis a Student t-test was performed.

RESULTS

The infusion of propofol led to slowly developing anaesthesia with loss of eyelash reflex followed by loss of pain response, respiratory insufficiency, and intubation. In the younger patients the clinical signs coincided with well-differentiable EEG patterns. Above 70 years of age there were problems in distinguishing the EEG patterns, as there are alterations of the EEG with advanced age. The multiparametric EEG stage calculated by the Narkograph showed a better correlation with the clinical signs than median or SEF. Fentanyl shortened the induction time remarkably: less propofol was needed to achieve corresponding clinical signs when fentanyl was added. The EEG patterns typical for a specific clinical condition remained unchanged by fentanyl. Similar clinical situations showed equal EEG stages in all groups. Different clinical situations could be distinguished by significant changes in the EEG. The infusion times for tolerance to pain and respiratory insufficiency were not significantly different, and there were no significant differences between the EEG patterns and propofol doses for these two clinical parameters. Intubation was performed after 18.5 +/- 4.6 min in group I with a propofol dose of 5.6 +/- 1.4 mg/kg. This time was shortened by fentanyl in group II to 10.1 +/- 3.7 min and a propofol dose of 3.0 +/- 1.1 mg/kg.

CONCLUSIONS

Different clinical signs corresponding to different levels of depth of anaesthesia could be differentiated by their EEG parameters. The EEG stage allowed better differentiation of the clinical conditions than the single-parameter EEG derivatives median and SEF. The results of this study show that EEG monitoring provides information about depth of anaesthesia.

OBJECTIVE

This study investigated how participation in leisure-time physical activity (LTPA) and physical fitness (PF) in adolescence (age 12-18) predict self-estimated physical fitness (SEF) in adulthood (age 37-43).

METHODS

A 25-year longitudinal population-based sample was investigated in two assessment points. In 1976 physical fitness was measured by five field tests and self-reported weekly frequency of LTPA was obtained by questionnaire. The sum indices of PF and LTPA were calculated. In 2001 (N=1321) self-estimated fitness was estimated by the questionnaire and calculated the sum of self-estimated fitness index. After this subjects were divided into three categories according to their level of fitness and leisure-time physical activity in adolescence and self-estimated fitness in adulthood (high, average and low).

RESULTS

LTPA and PF in adolescence correlated with SEF in adulthood among both males and females. In regression analyses, the odds ratio (OR) for a low fitness estimation as an adult for those who were very active in adolescence compared to those who were inactive in adolescence was 0.18 for both sexes. Among males the OR for low fitness estimation as an adult was 0.19 and females 0.14 in the highest compared to lowest fitness group in adolescence.

CONCLUSIONS

Results indicated that associations for self-estimated fitness from adolescence to adulthood were stronger in fitness than in leisure-time physical activity. The risk of adult low self-estimated fitness level was significantly lower for subjects who were physically very active or on the high fitness level in adolescence compared to persons on the low activity or low fitness level.

OBJECTIVE

Frequency organization in the human somatosensory cortex was studied.

METHODS

Somatosensory evoked magnetic fields (SEFs) from 12 subjects were measured following vibratory stimulation of the index finger by using a 122 channel whole head SQUID system. Sensory stimuli comprising a 40 ms vibration at frequencies of 50, 100, 200 and 400 Hz were delivered to the volar surface of the tip of the right index finger. Using a single dipole model, the sources of the magnetic fields were estimated and mapped onto magnetic resonance images of each subject. The analysis of variance test (ANOVA) was used for statistics.

RESULTS

Source localization was determined on the main two peaks (M60 and M110) of the SEFs. All of the sources were located in the area 3b of somatosensory cortex (SI). There were no statistically significant differences between the locations of the dipoles evoked by different frequency stimulations.

CONCLUSIONS

These results demonstrate the absence of systematic frequency organization at the hand representation area of the SI cortex. We speculate that high frequency vibration above 100 Hz are coded by the fast-spiking interneurons which synapse with Pacinian pyramidal neurons in SI.

Decision-making and memory are fundamental processes for successful human behaviour. For eye movements, the frontal eye fields (FEF), the supplementary eye fields (SEF), the dorsolateral prefrontal cortex (DLPFC), the ventrolateral frontal cortex and the anterior cingulum are important for these cognitive processes. The online approach of transcranial magnetic stimulation (TMS), i.e., the application of magnetic pulses during planning and performance of saccades, allows interfering specifically with information processing of the stimulated region at a very specific time interval (chronometry of cortical processing). The paper presents studies, which showed the different roles of the FEF and DLPFC in antisaccade control. The critical time interval of DLPFC control seems to be before target onset since TMS significantly increased the percentage of antisaccade errors at that time interval. The FEF seems to be important for the triggering of correct antisaccades. Bilateral stimulation of the DLPFC could demonstrate parallel information-processing transfer in spatial working memory during memory-guided saccades.

The Sucking Efficiency (SEF) is one of the main parameters used to monitor and assess the sucking pattern development in infants. Since Nutritive Sucking (NS) is one of the earliest motor activity performed by infants, its objective monitoring may allow to assess neurological and motor development of newborns. This work proposes a new ecological and low-cost method for SEF monitoring, specifically designed for feeding bottles. The methodology, based on the measure of the hydrostatic pressure exerted by the liquid at the teat base, is presented and experimentally validated at different operative conditions. Results show how the proposed method allows to estimate the minimum volume an infant ingests during a burst of sucks with a relative error within the range of [3-7]% depending on the inclination of the liquid reservoir

Transport of 22Na and 14C-butyrate across the ruminal epithelium of captive reindeer fed a concentrate diet in summer (n=5) and in winter (n=5) and from free-ranging reindeer taken from summer (n=3) and winter pasture (n=5) was measured in vitro in Ussing chambers. Significant amounts of both Na+ and butyrate were transported across the isolated epithelium without any external driving force. The ruminal transport of Na+ and butyrate were interacting, as evidenced by both the observed amiloride-induced reduction of net butyrate-transport and by the positive correlation between net transport of butyrate and Na+. Amiloride also reduced the net transport of Na+ without significantly affecting the short-circuit current, indicating the presence of an apical Na+/H+ exchanger in the ruminal epithelium of reindeer. The captive reindeer increased the dry matter intake of a constant quality concentrate from winter to summer, but this neither affected their ruminal transport capacity nor their ruminal surface enlargement factor (SEF). Free-ranging reindeer increased their ruminal transport capacity for Na+ and butyrate from summer to winter but simultaneously reduced their ruminal SEF. The present data indicate that this food-induced increase in transport capacity was attributed to changes in the nutrient composition of the diet.

Somatosensory evoked magnetic fields (SEFs) to contralateral median and ulnar nerve stimulation were analyzed in 10 patients with multiple sclerosis and in 8 healthy controls. SEFs were recorded with a 24-channel SQUID gradiometer over both hemispheres. Seven patients showed abnormally large-amplitude SEF deflections at 60-80 msec; 5 of them had multiple lesions around lateral ventricles in magnetic resonance imaging. In 2 patients with plaques at the level of 3rd and 4th ventricles and medulla, the 30 msec responses were enlarged. The equivalent sources of 20 msec and 30-80 msec responses were in the primary hand sensorimotor cortex both in patients and in control subjects. The results suggest that early and middle-latency SEFs reflect parallel processing of somatosensory input. Recording of middle-latency evoked responses, electric or magnetic, may give additional information about the somatosensory function in multiple sclerosis.

The ability of opiates to be a complete anesthetic has been assessed in animals. These studies have investigated the serum levels of opiate required to produce a decrease in anesthetic requirement for a concomitantly administered inhalation anesthetic. A linear dose-response relation has been observed between opiate serum level and reduction in anesthetic requirement up to the level of 50% reduction in minimum alveolar anesthetic concentration (MAC). These studies have not demonstrated the production of one MAC anesthesia by the opiates. Recent EEG studies have provided another means of comparing the central nervous system effects of opiates and inhalation anesthetics. The serum levels of several opiates associated with a 50% reduction (IC50 or 50% inhibitory concentration) in maximal spectral edge frequency (SEF) have been reported. The free, unionized serum levels of each opiate at IC50 in humans or 50% MAC reduction in animals are remarkably similar. We calculated brain lipid opiate content at these serum levels using available physiochemical data. The calculated nanogram and molar brain lipid contents of the drugs fell within a 10-fold range while serum levels varied by 5000-fold. This similarity in membrane lipid content in association with EEG and anesthetic effects suggests that opiate "anesthesia" may involve a membrane effect in addition to the well established receptor interaction.

Modelling transversely isotropic materials in finite strain problems is a complex task in biomechanics, and is usually addressed by using finite element (FE) simulations. The standard method developed to account for the quasi-incompressible nature of soft tissues is to decompose the strain energy function (SEF) into volumetric and deviatoric parts. However, this decomposition is only valid for fully incompressible materials, and its use for slightly compressible materials yields an unphysical response during the simulation of hydrostatic tension/compression of a transversely isotropic material. This paper presents the FE implementation as subroutines of a new volumetric model solving this deficiency in two FE codes: Abaqus and FEBio. This model also has the specificity of restoring the compatibility with small strain theory. The stress and elasticity tensors are first derived for a general SEF. This is followed by a successful convergence check using a particular SEF and a suite of single-element tests showing that this new model does not only correct the hydrostatic deficiency but may also affect stresses during shear tests (Poynting effect) and lateral stretches during uniaxial tests (Poisson's effect). These FE subroutines have numerous applications including the modelling of tendons, ligaments, heart tissue, etc. The biomechanics community should be aware of specificities of the standard model, and the new model should be used when accurate FE results are desired in the case of compressible materials.

The multiple pregnancy rate in assisted reproduction treatment cycles depends, fundamentally, on the number of embryos transferred. It is essential that patients and professionals should have good practical guidelines on the best number of embryos to be transferred in each cycle in order to obtain high pregnancy rates with minimal risk of multiple pregnancies. This study analysed the impact made by the Spanish Fertility Society (SEF) guidelines on the number of embryos to be transferred, as regards the policies adopted at clinics in Spain and the resulting financial repercussions. Data were collected from the assisted reproduction treatment register of the SEF and compared over three periods of time: 2002-2003, with no legal regulation and no SEF guidelines; 2004, with only legal regulation; and 2005-2006, with legal regulation and SEF guidelines. The acceptance of SEF guidelines varies according to the IVF technique. The guidelines have led to a reduction in multiple pregnancy rates, especially concerning triplets, in patients' own-egg and with donor-egg cycles. Even without full implantation, these results validate the clinical utility of the SEF guidelines. They constitute a useful tool to reduce the incidence of the principal adverse effect of treatment cycles: multiple pregnancies. The multiple pregnancy rate in assisted reproduction cycles depends fundamentally on the number of embryos transferred. It is essential that patients and professionals should have good practical guidelines on the best number of embryos to be transferred in each cycle in order to obtain high pregnancy rates with minimal risk of multiple pregnancies. The purpose of this study was to analyse the impact made by the Spanish Fertility Society (SEF) guidelines on the number of embryos to be transferred, as regards the policies adopted at clinics in Spain, and the resulting financial repercussions. Data were collected from the assisted reproduction register of the SEF and compared over three periods of time: 2002-2003, when there was no legal regulation and no SEF guidelines; 2004, when there was only legal regulation; and 2005-2006, when there was legal regulation and SEF guidelines. The degree of acceptance of SEF guidelines varies according to the IVF technique employed. The guidelines have led to a reduction in multiple pregnancy rates, especially concerning triplets, using patients' own eggs and with donor eggs. The reduction in the financial cost of deliveries achieved in the years 2005-2006 ranged from 890,187 to 18,593,242 euros, and the incremental cost per percentage point of multiple pregnancy avoided is 2,989,613 euros. In conclusion, even without full implementation, these results validate the clinical utility of the SEF guidelines. They constitute a useful tool to reduce the incidence of the principal adverse effect of assisted reproduction cycles, namely multiple pregnancies.