Miracle-dz/UniFAR-FTUs huggingface dataset:
IMAGERIE ACOUSTIQUE EN MILIEUX RÉVERBÉRANTS

Le travail de recherche mene lors de cette these propose d'ameliorer la comprehension et l'utilisation de champs d'ondes complexes issus de la propagation en milieux reverberants. Dans de tels milieux, la reverberation donne lieu a une repartition spatiale de l'intensite liee a la position de la source. Ce phenomene, appele retro-diffusion coherente, est etudie dans des cavites simples afin de disposer de modeles analytiques permettant de predire les resultats experimentaux de surintensite a la source. Les symetries spatiales jouent aussi un role dans la repartition de l'intensite, role qui est etudie selon la meme approche. La reverberation, aussi complexe soit-elle, contient des informations qui peuvent permettre d'imager le milieu de propagation. Ce principe est utilise pour l'elastographie, l'imagerie de l'elasticite des tissus mous. La problematique et les methodes d'elastographie sont alors presentees puis appliquees a la determination de delais electromecaniques dans des muscles squelettiques. Les methodes d'extraction de l'information contenue dans un champ complexe d'ondes elastiques sont ensuite developpees. Basee sur le retournement temporel et la correlation de bruit, une elastographie passive tirant profit du bruit physiologique est proposee. La faisabilite de cette methode est demontree a travers des mesures d'elasticite dans des gels et les premiers resultats in-vivo sont presentes. Finalement, une optimisation des methodes d'imagerie passive est developpee a partir de donnees sismiques. Le principe de ce filtre inverse passif consiste a mieux prendre en compte une repartition spatiale generalement inhomogene des sources de bruit.
Differential ontogenesis of presynaptic and postsynaptic GABAB inhibition in rat somatosensory cortex.

1. The postnatal maturation of gamma-aminobutyric acid (GABA)B receptor-mediated presynaptic inhibition was studied in brain slices of rat somatosensory cortex maintained in vitro. Patchclamp techniques were used to record whole-cell inhibitory post-synaptic currents from layer II-III neurons in animals from postnatal days (P) 7-24. Monosynaptic inhibitory postsynaptic currents (IPSCs) were evoked after N-methyl-D-aspartate (NMDA) and non-NMDA type glutamate receptors had been blocked by D-amino-phosphonovaleric acid (D-AP5, 20 microM) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 10 microM), respectively. These IPSCs were solely mediated by postsynaptic GABAA receptors because they were abolished by bicuculline (10 microM), reversed polarity near the chloride equilibrium potential, and were recorded with electrodes that contained Cs+ to block postsynaptic GABAB responses. 2. When pairs of stimuli separated by intervals of 0.1-10 s were used to evoke IPSCs, the second response was depressed, an effect that was maximal at 300 ms. Evoked IPSCs were also depressed by baclofen (10 microM). The paired pulse depression (PPD) of monosynaptic IPSCs was decreased or eliminated by 2-OH-saclofen (200 microM). These findings indicate that PPD of monosynaptic IPSCs was due to presynaptic GABAB receptor-mediated inhibition of GABA release. 3. There were no significant differences in the amounts of PPD in neurons from different age groups (P7-10, P12-17, P22-24) at any interstimulus interval tested (0.1-10 s). (ABSTRACT TRUNCATED AT 250 WORDS)
Paced breathing in roller-ski skating: effects on metabolic rate and poling forces.

PURPOSE This study aimed (1) to determine whether paced breathing (synchronization of the expiration phase with poling time) would reduce the metabolic rate and dictate a lower rate of perceived exertion (RPE) than does spontaneous breathing and (2) to analyze the effects of paced breathing on poling forces and stride-mechanics organization during roller-ski skating exercises. METHODS Thirteen well-trained cross-country skiers performed 8 submaximal roller-skiing exercises on a motorized driven treadmill with 4 modes of skiing (2 skating techniques, V2 and V2A, at 2 exercise intensities) by using 2 patterns of breathing (unconscious vs conscious). Poling forces and stride-mechanics organization were measured with a transducer mounted in ski poles. Oxygen uptake (VO2) was continuously collected. After each bout of exercise RPE was assessed by the subject. RESULTS No difference was observed for VO2 between spontaneous and paced breathing conditions, although RPE was lower with paced breathing (P < .05). Upper-limb cycle time and recovery time were significantly (P < .05) increased by paced breathing during V2A regardless of the exercise intensity, but no changes for poling time were observed. A slight trend of increased peak force with paced breathing was observed (P = .055). CONCLUSION The lack of a marked effect of paced breathing on VO2 and some biomechanical variables could be explained by the extensive experience of our subjects in cross-country skiing.
Euthyroid sick syndrome in head injury patients compared with Glasgow Coma and Outcome Scales.

BACKGROUND Evaluation of the role of euthyroid sick syndrome and pituitary gland hormonal changes and the prognosis of patient mortality after severe brain injury. METHODS The research was conducted on 65 patients with isolated severe brain injury. Blood samples were obtained as soon as possible after the injury and on the 1st, 2nd, 3rd, 5th and 7th day after the injury. Blood concentrations of T(3), rT(3), T(4), FT(4), TSH, and PRL were estimated. The patients' state of health was evaluated in the sixth hour after the injury, using Glasgow Coma Scale, and after 180 days, using the Glasgow Outcome Scale. Multidirectional correlation was sought between the concentrations of the estimated hormones and the score obtained in the Glasgow Coma Scale and Glasgow Outcome Scale. RESULTS Cluster analysis showed that concentrations of the hormones in the patients who died are grouped in different clusters from those in the patients who survived. This proves that hormonal patterns are different in these groups. Statistically significant lower T(3) concentrations were observed on the 3rd day in comparison with the 0 day. Cumulative proportion surviving was lower for the OP group in comparison with the NOP group and amounted to 0.57. CONCLUSIONS In all patients covered by the research euthyroid sick syndrome was diagnosed. T(3) concentration on the 3rd day after the injury together with the evaluation in Glasgow Coma Scale allows for more precise prognosis.
ATTENTIONAL BIAS TEMPORAL DYNAMICS PREDICT POSTTRAUMATIC STRESS SYMPTOMS: A PROSPECTIVE–LONGITUDINAL STUDY AMONG SOLDIERS

Attentional bias (AB) to threat is thought to play a key role in the development and maintenance of posttraumatic stress symptomatology (PTS). Empirical evidence though is inconsistent. Some studies report associations between AB towards, threat and PTS; other studies report associations between AB away from threat and PTS; yet other studies fail to find any association. We propose that prospective–longitudinal study of AB as a dynamic process, expressed from moment to moment in time, may help to understand these mixed findings and the role of AB in PTS.
Quantification of Fat Content and Fatty Acid Composition Using Magnetic Resonance Imaging

In obesity and several other disease scenarios, the measurement of fat accumulation in various organs and tissues has become a sought-after technique in clinical diagnostics and research. Especially, quantitative and non-invasive techniques which also provide images of accumulated fat throughout the body would be valuable. In the typical hospital, magnetic resonance imaging (MRI) is the only technique available which has the potential for these types of measurements and out of techniques suggested, Water/Fat Imaging is particularly promising. Water/Fat Imaging is based on the separation of water and fat, the two main contributors to the MRI signal, with the use of the frequency separation between their signals. The field has inspired a wide range of research and is by now well established, especially for investigations of fatty liver. However, in this and several other applications there is a continued need for method development. The fat concentrations in skeletal muscle are expected to be very low. Thus, for this application, there is an increased demand for measurement precision. The results presented in this thesis indicate that fat concentrations below 1 % are possible to measure using Water/Fat Imaging. In addition, precision may be increased using a higher flip angle if a pure fat reference is used for quantification, without compromising quantification accuracy. (Papers I and II) Water/Fat Imaging has become an appreciated technique for abdominal applications in which breath-hold is necessary for acceptable image quality. The use of a bipolar acquisition scheme may be used to reduce the total scan time, but is associated with issues which are detrimental to fat quantification. Using a built-in correction approach, it is demonstrated that accurate and noise efficient fat quantification is possible using a bipolar acquisition. (Paper III) The basic ideas of Water/Fat Imaging may be extended to not only quantify the fat concentration, but also the fatty acid composition. In this thesis, a reconstruction algorithm is suggested and its accuracy is demonstrated in a wide range of fat concentrations and fatty acid compositions. In addition, a number of potential sources of bias are investigated. Out of these, accurate modeling of the individual T2 values of fat and water is especially important in fat/water mixtures, whereas some T1 weighting may be allowed with small impact on quantification accuracy. (Papers IV and V)
Unveiling the nature of the highly absorbed X-ray source SAX J1748.2-2808 with XMM-Newton

We report on the results of an EPIC XMM-Newton observation of the faint source SAX J1748.2-2808 and the surrounding field. This source was discovered during the BeppoSAX Galactic center survey performed in 1997–1998. A spatial analysis resulted in the detection of 31 sources within the EPIC field of view. SAX J1748.2-2808 is clearly resolved into 2 sources in EPIC images with the brighter contributing almost 80% of the 2–10 keV flux. Spectral fits to this main source are consistent with an absorbed power-law with a photon index of $1.4\pm 0.5$ and absorption equivalent to $14 ^{+6} _{-4}\times 10^{22}$ cm -2 together with an iron line at $6.6 ^{+0.2} _{-0.2}$ keV with an equivalent width of $780 ^{+620}_{-380}$ eV. The significantly better statistics of the XMM-Newton observation, compared with BeppoSAX, allows to exclude a thermal nature for the X-ray emission. A comparison with other observations of SAXJ1748.2-2808 does not reveal any evidence for spectral or intensity long-term variability. Based on these properties we propose that the source is a low-luminosity high-mass X-ray binary located in the Galactic center region.
Thermally Induced Phase Changes, Lateral Heterogeneity of the Mantle, Continental Roots, and Deep Slab Anomalies

Pressure-induced solid-solid phase changes are responsible for most of the increase of density and seismic velocity with depth in the upper mantle. Lateral variations in temperature cause a similar effect; abrupt changes of density and seismic velocity due to phase changes are superposed on smaller changes associated with thermal expansion. Temperature-induced isobaric phase changes are as important in explaining various recent geophysical data as are the more familar pressure-induced phase changes. In cold slabs the equilibrium mineral assemblage contains high-density, high-velocity phases which are not stable in hotter mantle. In particular, the ilmenite form of MgSiO_3 and the γ-spinel form of Mg_2SiO_4 have broad stability fields in cold mantle which increase the density and velocity of deep slabs to values in excess of those which have been used in geoid and seismic travel time modeling. Recent arguments for slab penetration into the lower-mantle and whole mantle convection are based on thermal models of the slab which ignore the large density and seismic velocity anomalies associated with temperature-induced phase changes. When these effects are taken into account, the geoid and seismic anomalies associated with subducted slabs are consistent with slab confinement to the upper mantle and layered models of mantle convection. The seismicity cutoff and evidence for slab thickening at 670 km also favor this style of convection. Mantle seismic velocities between 200 and 400 km depth in tectonic and young oceanic regions are lower than in shield regions, and this is due to the presence of a melt phase and lower-velocity, high-temperature phase assemblages. Deep, > 200 km, long-lived continental roots, differing in chemistry from “normal” mantle, are not required when isobaric phase changes are taken into account. High-velocity subshield mantle is closer to normal subsolidus mantle than is suboceanic mantle which is affected by the presence of high-temperature phase assemblages. The whole mantle convection, thick continental root, and deep slab penetration hypotheses are not supported by seismic and geoid data when isobaric phase changes are included in the analysis. Phase changes are more effective in changing density and seismic velocity than are lateral variations in temperature and composition. The lack of correlation of the geoid with ridges, shields, heat flow, and upper mantle velocity variations suggests a low geoid sensitivity to the upper mantle, consistent with layered convection.
Synemin May Function to Directly Link Muscle Cell Intermediate Filaments to Both Myofibrillar Z-lines and Costameres*

Synemin is a large intermediate filament (IF) protein that has been identified in all types of muscle cells in association with desmin- and/or vimentin-containing IFs. Our previous studies (Bellin, R. M., Sernett, S. W., Becker, B., Ip, W., Huiatt, T. W., and Robson, R. M. (1999) J. Biol. Chem. 274, 29493–29499) demonstrated that synemin forms heteropolymeric IFs with major IF proteins and contains a binding site for the myofibrillar Z-line protein α-actinin. By utilizing blot overlay assays, we show herein that synemin also interacts with the costameric protein vinculin. Furthermore, extensive assays utilizing the Gal4 yeast two-hybrid system demonstrate interactions of synemin with desmin and vimentin and additionally define more precisely the protein subdomains involved in the synemin/α-actinin and synemin/vinculin interactions. The C-terminal ∼300-amino acid region of synemin binds to the N-terminal head and central rod domains of α-actinin and the ∼150-amino acid C-terminal tail of vinculin. Overall, these interactions indicate that synemin may anchor IFs to myofibrillar Z-lines via interactions with α-actinin and to costameres at the sarcolemma via interactions with vinculin and/or α-actinin. These linkages would enable the IFs to directly link all cellular myofibrils and to anchor the peripheral layer of myofibrils to the costameres.
A multi-level analysis of cultural experience and gender influences on causal attributions to perceived performance in mathematics.

BACKGROUND Causal attributions to academic performance are among the most important factors that influence the student's subsequent achievement behaviour. AIM The effects of student's gender and cultural experience (region) on the ratings of previously identified causal attribution factors were investigated. SAMPLE The participants were 341 high school students from the urban (N = 144) and the rural (N = 197) regions of Kenya. There were 205 male and 136 female students. METHODS Causal comparative research design was used and data collected using the Causal Attribution Scale (CAS). The Hierarchical linear model (HLM) technique was used to test the hypotheses. RESULTS There were significant gender and cultural experience variations in the mean ratings of the attribution factors. Instructional Strategy was highly rated for perceived success, and lack of Ability for perceived failure. Effort was of least importance in making attribution to either perceived success or failure. CONCLUSIONS The findings do not concur with research findings from Western and Asian countries where Effort is considered important in making attributions for either perceived success or failure. The findings, however, agree with research findings from Asian and other non-Caucasian societies where success is attributed to external factors (e.g., task difficulty) and failure to internal factors (e.g., ability). These findings have some implications for cross-cultural research in causal attribution as it relates to academic performance. While certain causal attributions studied in 'Western' and Asian cultures differ in terms of perceived success and failure, the current study indicates that other causal attributions are important and used differently by students from Kenya.
Poorly performing point-of-care tests for chlamydia: what can be done?

van Dommelen et al 1 ( see page 355 )convincingly show the problems associated with some Chlamydia trachomatis point-of-care (POC) tests that have concerned many of us for some time.2 They have looked at three commercially available Conformitee Europeene (CE)-marked kits and compared the results with the current ‘gold standard’, a nucleic acid amplification test (NAAT). Testing was carried out in what might be regarded as optimal conditions by healthcare professionals and even so the authors describe ‘alarmingly poor performance’, particularly in terms of sensitivity and positive predictive value. The results obtained would have led to infections being missed and to those with false-positive results being treated unnecessarily. With growing awareness of the development of antimicrobial …
Potentiation of Myelosuppression from Cancer Chemotherapy and Thiazide Diuretics

Fourteen patients with metastatic breast cancer and concomitant essential hypertension received treatment with combination chemotherapy (cyclophosphamide, methotrexate, and 5-fluorouracil) and thiazide diuretics. Significant augmentation of granulocytopenia during thiazide-chemotherapy combination, as compared with chemotherapy without thiazides, was observed in all patients. The most consistent changes in the neutrophil count were observed during the period of maximal myelosuppression from the antitumor drugs. An interaction between the thiazide diuretic and one or more of the cytotoxic agents is a possible explanation for the findings. The implications of this phenomenon are discussed.
Liquid chromatographic–electrospray mass spectrometric determination of 1-methyl-4-phenylpyridine (MPP+) in discrete regions of murine brain

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is widely used as a neurotoxin in several models of Parkinson’s disease in mice. MPTP is metabolized to 1-methyl-4-phenylpyridinium (MPP+), which is a mitochondrial toxicant of central dopamine (DA) neurons. There are species, strain, and age differences in sensitivity to MPTP. Simultaneous measurement of the MPTP active metabolite MPP+ and dopamine (DA) in the brain would be helpful in mechanistic studies of this neurotoxin. The objective of this study was to develop a liquid chromatography–mass spectrometry (LC/MS) method for analysis of MPTP and MPP+ in brain tissue and correlate these in the same sample with changes in DA measured via HPLC coupled with electrochemical detection. Twenty-five C57BL/6J7 8-week old female mice were used in the study. Mice were given a single subcutaneous injection of MPTP (20 mg/kg) and were sacrificed 1, 2, 4, or 8 h later. Zero time control mice received an injection of 0.9% normal saline (10 ml/kg) and were killed 1 h later. Brains were rapidly harvested and quickly frozen, and microdissected brain regions were placed in 0.1 M phosphate-citric acid buffer containing 20% methanol (pH 2.5). A new LC/MS method was successfully developed that utilized selected reaction monitoring (SRM) of MPP+ m/z 170→127, 170→128, and 170→154 fragmentation for quantitation and area ratios (m/z 127)/(m/z 128) and (m/z 154)/(128) for identity confirmation. A similar SRM strategy from m/z 174 was unable to detect any significant levels of MPTP down to 0.4 ppb. According to this method, MPP+ was detected in the nucleus accumbens (NA) and the striatum (ST), with the levels in the NA being 3-times higher than those in the ST. The advantage of this approach is that the tissue buffer used in this procedure allowed concurrent measurement of striatal DA, thus enabling direct correlation between accumulation of tissue MPP+ and depletion of DA concentrations in discrete regions of the brain.
Structural Origins of the Insulin-mimetic Activity of Bis(acetylacetonato)oxovanadium(IV)*

We have investigated the interaction of bis(acetylacetonato)oxovanadium(IV) (VO(acac)2) with bovine serum albumin (BSA) by EPR and angle-selected electron nuclear double resonance, correlating results with assays of glucose uptake by 3T3-L1 adipocytes. EPR spectra of VO(acac)2 showed no broadening in the presence of BSA; however, electron nuclear double resonance titrations of VO(acac)2 in the presence of BSA were indicative of adduct formation of VO(acac)2 with albumin of 1:1 stoichiometry. The influence of VO(acac)2 on uptake of 2-deoxy-d-[1-14C]glucose by serum-starved 3T3-L1 adipocytes was measured in the presence and absence of BSA. Glucose uptake was stimulated 9-fold in the presence of 0.5 mm VO(acac)2, 17-fold in the presence of 0.5 mm VO(acac)2 plus 1 mm BSA, and 22-fold in the presence of 100 nm insulin. BSA had no influence on glucose uptake, on the action of insulin, or on glucose uptake in the presence of VOSO4. The maximum insulin-mimetic effect of VO(acac)2 was observed at VO(acac)2:BSA ratios less than or equal to 1.0. Similar results were obtained also with bis(maltolato)oxovanadium(IV). These results suggest that the enhanced insulin-mimetic action of organic chelates of VO2+ may be dependent on adduct formation with BSA and possibly other serum transport proteins.
A Reliability and Validity Study of the Cornell Scale among Elderly Inpatients, Using Various Clinical Criteria

Background: The validity of the Cornell Scale for Depression in Dementia is seldom studied in institutions. Method: Two reliability studies, with 103 and 32 patients, and a validity study with 231 patients in nursing homes and in hospital were performed. They were assessed by the Cornell Scale, Clinical Dementia Rating scale and Self-Maintenance scale. A psychiatrist ‘blind’ to the Cornell assessment diagnosed depression according to the ICD-10, DSM-IV-TR and the Provisional Criteria for Depression in Alzheimer’s Disease (PCD-dAD). Results: Cronbach’s α values were 0.81 and 0.95, and the mean ĸ for the Cornell items were 0.91 and 0.57, respectively. In the validity study, 164 subjects had dementia; 105 (45.5%) had depression according to the ICD-10, 68 (29.9%) according to the DSM-IV-TR and 88 (53.3%) of the demented patients had depression according to the PCD-dAD. In the receiver operating characteristic analysis, the DSM-IV-TR criteria produced the highest area under the curve, i.e. 0.81 (95% CI: 0.75–0.87). A range of cutoff points for a depressive disorder was found for the various clinical criteria. Conclusion: The Cornell Scale is reliable and a range of cutoff points should be used for various clinical criteria of depression.