Non-invasive acquisition of fetal ECG from the maternal xyphoid process: a feasibility study in pregnant sheep and a call for open data sets.

OBJECTIVE: The utility of fetal heart rate (FHR) monitoring can only be achieved with an acquisition sampling rate that preserves the underlying physiological information on the millisecond time scale (1000 Hz rather than 4 Hz). For such acquisition, fetal ECG (fECG) is required, rather than the ultrasound to derive FHR. We tested one recently developed algorithm, SAVER, and two widely applied algorithms to extract fECG from a single-channel maternal ECG signal recorded over the xyphoid process rather than the routine abdominal signal. APPROACH: At 126dG, ECG was attached to near-term ewe and fetal shoulders, manubrium and xyphoid processes (n = 12). fECG served as the ground-truth to which the fetal ECG signal extracted from the simultaneously-acquired maternal ECG was compared. All fetuses were in good health during surgery (pH 7.29 ± 0.03, pO2 33.2 ± 8.4, pCO2 56.0 ± 7.8, O2Sat 78.3 ± 7.6, lactate 2.8 ± 0.6, BE -0.3 ± 2.4). MAIN RESULT: In all animals, single lead fECG extraction algorithm could not extract fECG from the maternal ECG signal over the xyphoid process with the F1 less than 50%. SIGNIFICANCE: The applied fECG extraction algorithms might be unsuitable for the maternal ECG signal over the xyphoid process, or the latter does not contain strong enough fECG signal, although the lead is near the mother's abdomen. Fetal sheep model is widely used to mimic various fetal conditions, yet ECG recordings in a public data set form are not available to test the predictive ability of fECG and FHR. We are making this data set openly available to other researchers to foster non-invasive fECG acquisition in this animal model.

Preventing long-lasting fear recovery using bilateral alternating sensory stimulation: A translational study.

Posttraumatic stress disorder (PTSD) is a highly debilitating and prevalent psychological disorder. It is characterized by highly distressing intrusive trauma memories that are partly explained by fear conditioning. Despite efficient therapeutic approaches, a subset of PTSD patients displays spontaneous recurrence of traumatic memories after successful treatment. The development of animal behavioral models mimicking the individual variability in treatment outcome for PTSD patients represent therefore an important challenge as it allows for the identification of predicting factors of resilience or susceptibility to relapse. However, to date, only few animal behavioral models of long-lasting fear recovery have been developed and their predictive validity has not been tested directly. The objectives of this study were twofold. First we aimed to develop a simple animal behavioral model of long-lasting fear recovery based on auditory cued fear conditioning and extinction learning, which recapitulates the heterogeneity of fear responses observed in PTSD patients after successful treatment. Second we aimed at testing the predictive validity of our behavioral model and used to this purpose a translational approach based (i) on the demonstration of the efficiency of Eye Movement Desensitization and Reprocessing (EMDR) therapy to reduce conditioned fear responses in PTSD patients and (ii) on the implementation in our behavioral model of an electrical bilateral alternating stimulation of the eyelid which mimics the core feature of EMDR. Our data indicate that electrical bilateral alternating stimulation of the eyelid during extinction learning alleviates long-lasting fear recovery of conditioned fear responses and dramatically reduces inter-individual variability. These results demonstrate the face and predictive validity of our animal behavioral model and provide an interesting tool to understand the neurobiological underpinnings of long-lasting fear recovery.

Prefrontal neuronal circuits of contextual fear conditioning.

Over the past years, numerous studies have provided a clear understanding of the neuronal circuits and mechanisms involved in the formation, expression and extinction phases of conditioned cued fear memories. Yet, despite a strong clinical interest, a detailed understanding of these memory phases for contextual fear memories is still missing. Besides the well-known role of the hippocampus in encoding contextual fear behavior, growing evidence indicates that specific regions of the medial prefrontal cortex differentially regulate contextual fear acquisition and storage in both animals and humans that ultimately leads to expression of contextual fear memories. In this review, we provide a detailed description of the recent literature on the role of distinct prefrontal subregions in contextual fear behavior and provide a working model of the neuronal circuits involved in the acquisition, expression and generalization of contextual fear memories.

Segmentation and classification of capnograms: application in respiratory variability analysis.

Variability analysis of respiratory waveforms has been shown to provide key insights into respiratory physiology and has been used successfully to predict clinical outcomes. The current standard for quality assessment of the capnogram signal relies on a visual analysis performed by an expert in order to identify waveform artifacts. Automated processing of capnograms is desirable in order to extract clinically useful features over extended periods of time in a patient monitoring environment. However, the proper interpretation of capnogram derived features depends upon the quality of the underlying waveform. In addition, the comparison of capnogram datasets across studies requires a more practical approach than a visual analysis and selection of high-quality breath data. This paper describes a system that automatically extracts breath-by-breath features from capnograms and estimates the quality of individual breaths derived from them. Segmented capnogram breaths were presented to expert annotators, who labeled the individual physiological breaths into normal and multiple abnormal breath types. All abnormal breath types were aggregated into the abnormal class for the purpose of this manuscript, with respiratory variability analysis as the end-application. A database of 11,526 breaths from over 300 patients was created, comprising around 35% abnormal breaths. Several simple classifiers were trained through a stratified repeated ten-fold cross-validation and tested on an unseen portion of the labeled breath database, using a subset of 15 features derived from each breath curve. Decision Tree, K-Nearest Neighbors (KNN) and Naive Bayes classifiers were close in terms of performance (AUC of 90%, 89% and 88% respectively), while using 7, 4 and 5 breath features, respectively. When compared to airflow derived timings, the 95% confidence interval on the mean difference in interbreath intervals was ± 0.18 s. This breath classification system provides a fast and robust pre-processing of continuous respiratory waveforms, thereby ensuring reliable variability analysis of breath-by-breath parameter time series.

Persistence of amygdala gamma oscillations during extinction learning predicts spontaneous fear recovery.

Extinction of auditory fear conditioning induces a temporary inhibition of conditioned fear responses that can spontaneously reappear with the passage of time. Several lines of evidence indicate that extinction learning relies on the recruitment of specific neuronal populations within the basolateral amygdala. In contrast, post-extinction spontaneous fear recovery is thought to result from deficits in the consolidation of extinction memory within prefrontal neuronal circuits. Interestingly, recent data indicates that the strength of gamma oscillations in the basolateral amygdala during auditory fear conditioning correlates with retrieval of conditioned fear responses. In the present manuscript we evaluated the hypothesis that post-extinction spontaneous fear recovery might depend on the maintenance of gamma oscillations within the basolateral amygdala by using single unit and local field potential recordings in behaving mice. Our results indicate that gamma oscillations in the basolateral amygdala were enhanced following fear conditioning, whereas during extinction learning gamma profiles were more heterogeneous despite similar extinction learning rates. Remarkably, variations in the strength of gamma power within the basolateral amygdala between early and late stages of extinction linearly predicted the level of post-extinction spontaneous fear recovery. These data suggest that maintenance of gamma oscillations in the basolateral amygdala during extinction learning is a strong predictive factor of long term spontaneous fear recovery.

Medial prefrontal cortex neuronal circuits in fear behavior.

The medial prefrontal cortex (mPFC) has emerged as a key structure involved in the modulation of fear behavior over the past few decades. Anatomical, functional and electrophysiological studies have begun to shed light on the precise mechanisms by which different prefrontal regions regulate the expression and inhibition of fear behavior. These studies have established a canonical view of mPFC functions during fear behavior with dorsal regions selectively involved in the expression of fear behavior and ventral regions linked to the inhibition of fear behavior. Although numerous reports support this view, recent data have refined this model and suggested that dorsal prefrontal regions might also play an important role in the encoding of fear behavior itself. The recent development of sophisticated approaches such as large scale neuronal recordings, simultaneous multisite recordings of spiking activity and local field potentials (LFPs) along with optogenetic approaches will facilitate the testing of these new hypotheses in the near future. Here we provide an extensive review of the literature on the role of mPFC in fear behavior and propose further directions to dissect the contribution of specific prefrontal neuronal elements and circuits in the regulation of fear behavior.

Risks of non-lethal weapon use: case studies of three French victims of stinger grenades.

The development of non-lethal weapons started in the 1960s. In France, they have been used by the police for about 10 years. We relate the cases of three French women, victims of stinger grenades, non-lethal weapons recently adopted by the French law enforcement to distract and disperse crowds. The three victims presented serious injuries requiring emergency surgical care. One lost her eye. Based on these cases, we discuss the lethal character of these weapons and propose measures to be taken to prevent their dramatic consequences. Although the danger is obviously less than for firearms, stinger grenades are nonetheless potentially lethal and cause serious physical injuries.

Curing of aqueous polymeric film coatings: Importance of the coating level and type of plasticizer.

The aim of this study was to better understand the effects of the curing conditions on the resulting drug release patterns from pellets coated with aqueous polymer dispersions. Diltiazem HCl was used as model drug, ethylcellulose as polymer, triethyl citrate (TEC), dibutyl sebacate (DBS), and distilled acetylated monoglycerides (Myvacet) as plasticizers. Interestingly, the effects of the curing conditions strongly depended on the coating level and the type of plasticizer: in the case of TEC, the drug release rate monotonically decreased with increasing harshness of the curing conditions (time, temperature, and relative humidity), irrespective of the coating level. In contrast, in the case of DBS and Myvacet, this type of relationship was only observed at low coating levels (5%). At intermediate coating levels (around 7.5%), the curing conditions had virtually no effect on drug release. At high coating levels (10%), the release rate initially increased and then decreased with increasing harshness of the curing conditions. This more complex behavior might be attributable to the superposition of two competing phenomena: improved film formation and drug migration into the polymeric membrane. Furthermore, it could be shown that the type of plasticizer had a major effect on drug release in not fully coalesced and equilibrated film coatings, whereas the release profiles were similar for all plasticizers in the case of completely formed and equilibrated film coatings. Importantly, the latter systems were stable for long term even during storage under stress conditions.

Segmentation and landmark identification in infrared images of the human body.

The segmentation and landmark identification in infrared images of the human body are key steps in a computerized processing of large database of thermal images. The segmentation task is especially challenging due to specific characteristics of thermal images. Few papers deal with segmentation techniques for clinical infrared images and available segmentation methods (e.g. for breast or military thermal images) do not perform well on other types of images. This paper presents a few strategies for the automated segmentation and registration of anatomical landmarks on thermal images of arms and hands. The segmentation method is based on mathematical morphological operations and simple rule based processing easily available through prior knowledge about the objects of interest.

Evolution of the surface temperature of pianists' arm muscles using infrared thermography.

Musculoskeletal disorders are very frequent among musicians. Diagnosis is difficult due to the lack of objective tests and the multiplicity of symptoms. Treatment is also problematic and often requires that the musician stop playing. Most of these disorders are inflammatory in nature, and therefore involve temperature changes in the affected regions. Temperature measurements were recorded with an infrared camera. In this paper we present an overview of the temperature measurements made in the arms of 8 pianists during regular piano practice sessions.

Analysis of breast thermography with an artificial neural network.

Thermal imaging has been used for early breast cancer detection and risk prediction since the sixties. Examining thermograms for abnormal hyperthermia and hyper-vascularity patterns related to tumor growth is done by comparing images of contralateral breasts. Analysis can be tedious and challenging if the differences are subtle. The advanced computer technology available today can be utilized to automate the analysis and assist in decision-making. In our study, computer routines were used to perform ROI identification and image segmentation of infrared images recorded from 19 patients. Asymmetry analysis between contralateral breasts was carried out to generate statistics that could be used as input parameters to a backpropagation ANN. A simple 1-1-1 network was trained and employed to predict clinical outcomes based on the difference statistics of mean temperature and standard deviation. Results comparing the ANN output with actual clinical diagnosis are presented. Future work will focus on including more patients and more input parameters in the analysis. Performance of ANN network can be studied to select a set of parameters that would best predict the presence of breast cancer.

Automated image segmentation for breast analysis using infrared images.

In order to realize a fully automated thermogram analysis package for breast cancer detection, it is necessary to identify the region of interest in the thermal image prior to analysis. A nearly fully automated approach is outlined that is able to successfully locate the breast regions in most of the images analyzed. The approach consists of a sequence of Canny edge detectors to determine the body boundaries and to isolate the most likely candidates for the bottom breast boundary. Three different strategies for identifying the bottom breast boundary are investigated: a variation of the Hough transform to identify the curved edges in the image, an algorithm used to detect the longest connected edges that are not part of the body boundary, and a third approach involving the density of detected edges in the breast region. The last two methods show great promise in successfully segmenting the breasts.

Plasticity in the mediodorsal thalamo-prefrontal cortical transmission in behaving mice.

We studied changes in thalamo-prefrontal cortical transmission in behaving mice following both low-frequency stimulation of the mediodorsal thalamus (MD) and during extinction of a conditioned fear response. Electrical stimulation of the MD induces a field potential in the medial prefrontal cortex (mPFC) characterized by two initial negative-positive complexes (N1-P1 and N2-P2) followed by two positive-negative complexes (P2-N3 and P3-N4). The N1-P1 and N2-P2 complexes were identified as resulting from orthodromic and antidromic prefrontal activation, respectively. Because the two complexes were not often easily dissociated, plasticity in the prefrontal synaptic transmission was considered to result from changes in N1-P2 amplitude. Low-frequency thalamic stimulation (1, 200 pulses at 2 Hz) produced either long-term (at least 32 min) depression or potentiation of the N1-P2 amplitude. Mice submitted to fear conditioning (tone-shock association), displayed on the first day of extinction (tone-alone presentations) a strong freezing behavior, which decreased progressively, but was still high the following day. Extinction of conditioned fear was accompanied the first day by a depression of prefrontal transmission, which was converted into potentiation the following day. Potentiation of prefrontal transmission lasted at least 24 h following the second day of the fear extinction procedure. In conclusion, low-frequency thalamic stimulation can produce, in behaving mice, either depression or potentiation of prefrontal synaptic transmission. Decrease in prefrontal synaptic transmission observed during the first day of extinction may reflect processing of the high degree of predictiveness of danger (unconditioned stimulus: US) by the aversive conditioned stimulus (CS). However, the subsequent potentiation of transmission in the mPFC may be related to processing of cognitive information such as the CS will no longer be followed by the US, even if emotional response (freezing) to the CS is still high.

[Migrants in urban Mali. The need to survive surplants the desire to succeed]. / Les migrants en milieu urbain au Mali. L'imperatif de survie prend le pas sur le desir de reussir.

PIP: Preliminary data from a survey of migration in 4 cities of Mali, all located on the Niger river, are the basis for an assessment of the characteristics of migrants to the cities. Mali as a whole is still 80% rural, and urban migration does not absorb the entire natural increase of the countryside. But the arrival and absorption of rural migrants already poses serious problems. The study was conducted in 2 regional metropolises, Mopti and Segou, and 2 small cities, Dire and Ke-Macina. The average rate of growth of the cities, except Ke-Macina, was about 3%/year between 1976-87. The data presented in the article concern men who arrived at age 15 or older and who were aged 15-59 at the survey date. The average age of respondents at their 1st migration was surprisingly high: 26.2 years in Segou, 27.1 in Mopti, 28.7 in Dire, and 27.3 in Macina. Proportions ranging from 39.5% in Macina to 62.2% in Dire migrated directly to their current city. Apart from some migrants who were transferred to the 4 cities in the course of their employment, most of the migrants were poorly educated or illiterate. Around 70% had never had a job that was urban in character. About 1/4 spoke some French. 1/4 had no knowledge of Bambara, the most widely spoken language. None of the cities had secondary sectors in need of unskilled labor. Most migrants arrive with no means of support, but a large proportion can count on the assistance of previously migrated family members, at least for a time. Given the lack of preparation of most migrants, their assimilation into the labor force is difficult. They are absorbed into the least specialized and least well paying jobs. Primary sector jobs in agriculture or fishing retain considerable importance in these smaller cities. Most migrants do not encounter the means of improving their economic situation in the urban environment, and strategies for survival soon replace hopes of advancement.^ieng

[Infant and child mortality in Abidjan (1978-1979)]. / Mortalite infantile et juvenile a Abidjan (1978-1979)

PIP: Results from a national survey of infant and child mortality in the Ivory Coast are presented, with particular reference to the capital, Abidjan. The data are from a multi-round survey undertaken in 1978-1979. The authors challenge the concept of urban mortality and note significant differences in mortality levels among the various types of urban settlement. (summary in ENG, SPA)^ieng

[Urbanization and household size: the case of Abidjan]. / Urbanisation et dimension du menage: le cas d'Abidjan

PIP: The main characteristics of households in the city of Abidjan, Ivory Coast, are examined using data from a survey undertaken in 1978 and 1979. The authors note that there is a high degree of social stratification and that household characteristics and size vary significantly by residential area. It is also found that the extended family exists more frequently among long-term and affluent urban residents, while the nuclear family type is more frequent among recent and poorer urban migrants. (summary in ENG, SPA)^ieng

[The population of Abidjan within its walls: urban dynamics and the development of demographic structures between 1955 and 1978]. / La population d'Abidjan dans ses murs: dynamique urbaine et evolution des structures demographiques entre 1955 et 1978

PIP: The development of the population of Abidjan, capital of the Ivory Coast, is analyzed using data taken primarily from a multi-round survey conducted in 1978-1979. Consideration is given to changes in the age and sex structure of the population over time, nationality, and ethnic group of in-migrants. An attempt is made to categorize the various stages of development the city has gone through and to identify the many different environments and types of settlement within the urban boundaries.^ieng