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Background: Cervical sponylotic myelopathy (CSM) may present with neck and arm pain. This study investiagtes the change in neck/arm pain post-operatively in CSM. Methods: This ambispective study llocated 402 patients through the Canadian Spine Outcomes and Research Network. Outcome measures were the visual analogue scales for neck and arm pain (VAS-NP and VAS-AP) and the neck disability index (NDI). The thresholds for minimum clinically important differences (MCIDs) for VAS-NP and VAS-AP were determined to be 2.6 and 4.1. Results: VAS-NP improved from mean of 5.6±2.9 to 3.8±2.7 at 12 months (P<0.001). VAS-AP improved from 5.8±2.9 to 3.5±3.0 at 12 months (P<0.001). The MCIDs for VAS-NP and VAS-AP were also reached at 12 months. Based on the NDI, patients were grouped into those with mild pain/no pain (33%) versus moderate/severe pain (67%). At 3 months, a significantly high proportion of patients with moderate/severe pain (45.8%) demonstrated an improvement into mild/no pain, whereas 27.2% with mild/no pain demonstrated worsening into moderate/severe pain (P <0.001). At 12 months, 17.4% with mild/no pain experienced worsening of their NDI (P<0.001). Conclusions: This study suggests that neck and arm pain responds to surgical decompression in patients with CSM and reaches the MCIDs for VAS-AP and VAS-NP at 12 months.
Introduction: Identification of severe bacterial infections (SBI) among infants presenting to the emergency department (ED) for fever without a source (FWS) remains challenging. Controversies persist on the usefulness of blood biomarkers, especially when used for assessing infants 22 to 60 days old. Although C-reactive protein (CRP) and white blood cells count (leucocytes) are commonly prescribed, this practice relies on poor and conflicting evidence. Our objective was to determine the performance of those two markers at identifying SBI. Methods: This is a sub-analysis of an ongoing retrospective cohort study conducted in an academic pediatric ED in Quebec City, that aims to determine whether a lumbar puncture should routinely be performed in the FWS workup of 22 to 60 days old infants. All consecutive charts of eligible febrile infants were reviewed. Premature infants (<37 weeks), as well as infants with chronic diseases, immunodeficiency, previous antimicrobial therapy, in-dwelling catheters, or septic shock were excluded. Among others, data related to final diagnosis and investigations were gathered. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, positive (LR+) and negative (LR-) likelihood ratios were estimated for each blood biomarkers. Results: Out of 1261 charts reviewed, 920 patients were included in this analysis. SBI prevalence was 13.0% (95%CI: 10.9-15.2) among infants of our cohort. The sensitivity, specificity, PPV, NPV, LR+ and LR- of the leucocytes <5000 or≥15000/□L were 43% (95%CI: 34-53%), 80% (95%CI: 77-83%), 25% (95%CI: 21-30%), 90% (95%CI: 88-91%), 2.1 (95%CI: 1.7-2.8), and 0.72 (95%CI: 0.61-0.84), respectively. The sensitivity, specificity, PPV and NPV of CRP >= 25 mg/L were 46% (95%CI: 37-56%), 96% (95%CI: 94-97%), 65% (95%CI: 55-73%), and 91% (95%CI: 89-92%), respectively. ROC curves analysis indicates that a CRP≥25 mg/L offers the best LR+ (10.4; 95%CI: 6.9-15.6) with a corresponding LR- of 0.56 (95%CI: 0.47-0.67). Conclusion: When evaluating febrile infants in the ED, leucocytes appear to have limited added value, while CRP≥25 mg/L significantly increases the pre-test probability of SBI. CRP should be considered for inclusion in the workup of FWS for infants of 22 to 60 days of age.
Introduction: Fever is a common presenting complaint in the emergency department (ED). Febrile infants are at particularly high risk of serious bacterial infection including bacterial meningitis. Unfortunately, recommendations as to when to perform a lumbar puncture in febrile infants older than 21 days remain conflicting. Our study seeks to establish the prevalence of bacterial meningitis in infants 22 to 60 days old and to evaluate the performance of our local fever without a source (FWS) workup protocol at identifying bacterial meningitis. Methods: This analysis represents the results of a retrospective cohort study which took place in an academic pediatric ED in Quebec City. Infants 22 to 60 days old investigated for FWS, were included in the study. Premature infants ( <37 weeks), as well as infants with chronic diseases, immunodeficiency, previous antimicrobial therapy, in-dwelling catheters, or septic shock were excluded. We evaluated the performance of our local FWS workup protocol which includes the Yale Scale, a complete blood count, blood culture, C-reactive protein, urinalysis and urine culture. The protocol recommends a lumbar puncture in all febrile infants <1 month old, and in all infants <3 months old with either leukocytes <5.0 or >15.0 X 10^9cells/L, petechia, or a Yale between 11 and 16. Results: We reviewed 1261 charts from 2012 to 2017, of which 920 met our inclusion criteria. In our cohort, 171 infants were 22 to 30 days old, 369 were 31 to 45 days old, and 380 were 46 to 60 days old. The proportion of infants with cerebrospinal fluid analysis in these 3 groups was 76% (n = 130), 25% (n = 98) and 12% (n = 46) respectively. In the entire cohort, two infants were diagnosed with bacterial meningitis resulting in a prevalence of 0.2% (95%CI: 0-0.5%); viral meningitis had a prevalence of 4.7% (95%CI: 3.3-6.1%). Sensitivity and specificity of the protocol were 100% and 52.8%; positive and negative predictive values were 0.4% and 100%, respectively. All charts were reviewed for 2 weeks following the index visit to screen for missed cases of bacterial meningitis. Conclusion: Systematically performing a lumbar puncture for workup of fever without a source in infants 22 to 60 days old appears unwarranted given the low prevalence of bacterial meningitis in this population. Our FWS workup protocol correctly identified the 2 cases of bacterial meningitis in our cohort. This is an ongoing study and more cases will be recruited to better evaluate the safety and performance of our protocol.
Animal models of early postnatal mother–infant interactions have highlighted the importance of tactile contact for biobehavioral outcomes via the modification of DNA methylation (DNAm). The role of normative variation in contact in early human development has yet to be explored. In an effort to translate the animal work on tactile contact to humans, we applied a naturalistic daily diary strategy to assess the link between maternal contact with infants and epigenetic signatures in children 4–5 years later, with respect to multiple levels of child-level factors, including genetic variation and infant distress. We first investigated DNAm at four candidate genes: the glucocorticoid receptor gene, nuclear receptor subfamily 3, group C, member 1 (NR3C1), μ-opioid receptor M1 (OPRM1) and oxytocin receptor (OXTR; related to the neurobiology of social bonds), and brain-derived neurotrophic factor (BDNF; involved in postnatal plasticity). Although no candidate gene DNAm sites significantly associated with early postnatal contact, when we next examined DNAm across the genome, differentially methylated regions were identified between high and low contact groups. Using a different application of epigenomic information, we also quantified epigenetic age, and report that for infants who received low contact from caregivers, greater infant distress was associated with younger epigenetic age. These results suggested that early postnatal contact has lasting associations with child biology.
Early-onset conduct problems (CP) are a key predictor of adult criminality and poor mental health. While previous studies suggest that both genetic and environmental risks play an important role in the development of early-onset CP, little is known about potential biological processes underlying these associations. In this study, we examined prospective associations between DNA methylation (cord blood at birth) and trajectories of CP (4–13 years), using data drawn from the Avon Longitudinal Study of Parents and Children. Methylomic variation at seven loci across the genome (false discovery rate < 0.05) differentiated children who go on to develop early-onset (n = 174) versus low (n = 86) CP, including sites in the vicinity of the monoglyceride lipase (MGLL) gene (involved in endocannabinoid signaling and pain perception). Subthreshold associations in the vicinity of three candidate genes for CP (monoamine oxidase A [MAOA], brain-derived neurotrophic factor [BDNF], and FK506 binding protein 5 [FKBP5]) were also identified. Within the early-onset CP group, methylation levels of the identified sites did not distinguish children who will go on to persist versus desist in CP behavior over time. Overall, we found that several of the identified sites correlated with prenatal exposures, and none were linked to known genetic methylation quantitative trait loci. Findings contribute to a better understanding of epigenetic patterns associated with early-onset CP.
This study investigated the potential environmental effects of peer victimization and the quality of relationships with parents and friends on diurnal cortisol secretion in mid-adolescence.
This study used the monozygotic (MZ) twin-difference design to control for genetic effects and thus estimate the unique environmental influences on diurnal cortisol. Participants were 136 MZ twin pairs (74 female pairs) for whom cortisol was assessed four times per day over four collection days grouped in a 2-week period in grade 8 (mean age = 14.07 years). Participants also provided self-reports of peer victimization from grade 4 to grade 8 and of the relationship quality with the mother, father and best friend in grade 8.
The expected pattern of diurnal cortisol secretion was observed, with high levels at awakening followed by an increase 30 min later and a progressive decrease subsequently. Controlling for a host of confounders, only within-twin pair differences in peer victimization and a problematic relationship with the mother were significantly linked to twin differences in diurnal cortisol secretion. Specifically, whereas a more problematic mother–child relationship was associated with morning cortisol secretion, peer victimization was linked to cortisol secretion later in the day (diurnal slope).
Controlling for genetic influences and other confounders, stressful relationships with peers and the mother exert unique and time-specific environmental influences on the pattern of diurnal cortisol secretion in mid-adolescence.
Among the solar proxies, κ1 Cet, stands out as potentially having a mass very close to solar and a young age. We report magnetic field measurements and planetary habitability consequences around this star, a proxy of the young Sun when life arose on Earth. Magnetic strength was determined from spectropolarimetric observations and we reconstruct the large-scale surface magnetic field to derive the magnetic environment, stellar winds, and particle flux permeating the interplanetary medium around κ1 Cet. Our results show a closer magnetosphere and mass-loss rate 50 times larger than the current solar wind mass-loss rate when Life arose on Earth, resulting in a larger interaction via space weather disturbances between the stellar wind and a hypothetical young-Earth analogue, potentially affecting the habitability. Interaction of the wind from the young Sun with the planetary ancient magnetic field may have affected the young Earth and its life conditions.
Physical aggression (PA) tends to have its onset in infancy and to increase rapidly in frequency. Very little is known about the genetic and environmental etiology of PA development during early childhood. We investigated the temporal pattern of genetic and environmental etiology of PA during this crucial developmental period.
Participants were 667 twin pairs, including 254 monozygotic and 413 dizygotic pairs, from the ongoing longitudinal Quebec Newborn Twin Study. Maternal reports of PA were obtained from three waves of data at 20, 32 and 50 months. These reports were analysed using a biometric Cholesky decomposition and linear latent growth curve model.
The best-fitting Cholesky model revealed developmentally dynamic effects, mostly genetic attenuation and innovation. The contribution of genetic factors at 20 months substantially decreased over time, while new genetic effects appeared later on. The linear latent growth curve model revealed a significant moderate increase in PA from 20 to 50 months. Two separate sets of uncorrelated genetic factors accounted for the variation in initial level and growth rate. Non-shared and shared environments had no effect on the stability, initial status and growth rate in PA.
Genetic factors underlie PA frequency and stability during early childhood; they are also responsible for initial status and growth rate in PA. The contribution of shared environment is modest, and perhaps limited, as it appears only at 50 months. Future research should investigate the complex nature of these dynamic genetic factors through genetic–environment correlation (rGE) and interaction (G × E) analyses.
Spectropolarimetric observations combined with tomographic imaging techniques have revealed that all pre-main sequence (PMS) stars host multipolar magnetic fields, ranging from strong and globally axisymmetric with ≳kilo-Gauss dipole components, to complex and non-axisymmetric with weak dipole components (≲0.1 kG). Many host dominantly octupolar large-scale fields. We argue that the large-scale magnetic properties of a PMS star are related to its location in the Hertzsprung-Russell diagram. This conference paper is a synopsis of Gregory et al. (2012), updated to include the latest results from magnetic mapping studies of PMS stars.
An approximate late time solution to the dynamics of phase separation for a nonconserved ordering order parameter (ø) coupled to a stable conserved field (c) is presented. In the Halperin Hohenberg(1) classification scheme this model is known as Model C with a symmetric coupling between nonconserved and conserved fields. The different time dependences of long (i.e., domain size lengths ∼ power law in time) and short wavelength (i.e., interfacial lengths ∼ exponential decay in time) fluctuations imply a simple relationship between the two fields. In essence ø controls the growth of the long wavelength fluctuations, and c modifies the interfacial profile. Asymptotically the dynamic structure factor (Sø(k,t)≡<Ø(k,t)Ø*(k,t)>) for the nonconserved field is shown to scale in the form Sø(k,t) = tdnfø(ktn), with n = 1/2. Similarly the structure factor for the conserved field (Sc(k,t)) is shown to obey the scaling law Sc(k,t) = tdn−1fc(ktn), with n = 1/2. Explicit expressions for the scaling functions fc(z) and fø(z) are presented for arbitrary dimension. These predictions can be tested through scattering experiments.
We present a detailed study of the effects of a negative bias applied to the substrate on the electronic properties of a-Si:H films deposited by r.f. glow discharge. Two series of samples deposited at 30 and 100 mTorr respectively have been studied. For each series the negative d.c. bias applied to the substrate was decreased from 0 to −100 V in steps of 25 V. We observe for both series of samples an improvement of the electronic properties of the films as we decrease the substrate bias (increase the ion energy) down to − 50 V. We have found a clear correlation between the negative bias applied to the substrate and the subgap absorption, the valence band tail slope and the electron and hole μτ products.
An unexpected 18R martensite to martensite transformation was obtained in Cu-Zn-Al alloy during the training process for 18R single crystal preparation: this later was induced from a β1 single crystal by application of a constant tensile force at room temperature and by lowering the temperature until β1 -->18R transformation occurs. At this condition, and after several cycles, some plates of a new phase were observed to appear in a sudden way inside the 18R single crystal region. By studying the transformation characteristics as given by elongation temperature curves and trace analysis we conclude that this new phase plates are 2H martensite.
Explosive Crystallization occurs in cw laser annealing on a-Si films deposited on glass substrates at laser scan speeds higher than 30 cm/sec. Optical, structural and electrical properties of the crystallized films at various laser scan speeds confirm the existence of two kinds of explosive growth depending on the state of crystallinity of the starting material.
X-ray Absorption Spectroscopy (XAS) together with x-ray diffraction methods were used in inactive analogues of the French nuclear waste glass to analyze Pd-Te precipitates and the peculiarity of the sites occupied by some structural probe elements such as Mo, Zn, Zr and Si in the glassy part of the material. The influence of the precipitates on the structure of the glassy matrix around these structural probes was investigated by comparing noble metal bearing compositions together with noble metal free glasses.
In noble metal bearing glasses, Pd is associated to Te as (Pd90 Te10) precipitates. Pd K-edge EXAFS shows the presence of Te in the Pd coordination shell and is in accordance with a non-metallic character of the Pd-Te bond. Mo K-edge EXAFS shows that Mo occurs as molybdate groups non connected to the glassy matrix, which may be related to the occasional separation of Mo-rich phases in some compositions. Zr is located in an octahedron with d(Zr-O)=2.08Å 0.01Å whereas Zn is 4-fold coordinated with d(Zn-0)=-1.95 Å± 0.01Å. Beyond this well defined first coordination shell, XAS detects some degree of medium range order which gives insight on the bonding of the site to the polymeric borosilicate network. The interatomic Zn-Si and Zr-Si EXAFS-determined distances agree with a ZnO4 and Si04 tetrahedra sharing corners geometry and Zr-Si octahedra sharing corner with Si04 tetrahedra. A third shell of neighbors around Zr was evidenced in the noble metal bearing glasses and in a four oxide glass, indicating that Zr is an element useful for detecting subtle changes in the local structure of complex borosilicate glasses. Si K XANES shows modifications in the connection between Si04 tetrahedra when noble metals are present. To obtain accurate and precise structural interpretations, a direct comparison between EXAFS data and Molecular Dynamic (M.D.) calculations on simplified nuclear glass comprising six oxides has been performed. MD calculations show that the distribution of the Zr-O distances is harmonic in the k-range accessible with EXAFS in glasses.
This paper proposes a practical approach for developing a new class of compact slow-wave coplanar waveguide (CPW) series/shunt stubs, which offer 40% reduction in size relative to a conventional design. It demonstrates that the technique using interdigitated capacitive loading can provide size and cost reductions, while also providing performance enhancements such as better return loss. The experimental prototypes presented in this paper demonstrate the validity of the design method and the ability to print interdigitated capacitors inside the center conductor of the series/shunt stubs. The principle of achieving such high-quality circuits is detailed and is also confirmed by theoretical and experimental results, which are in reasonable agreement up to at least 70 GHz. The paper also presents a family of novel topologies of slow wave bandpass filters based on the proposed capacitively loaded CPW series/shunt stubs.
The eastern English Channel, the narrow channel of water separating northern
France and southeast England is an area of intense human use of the array of
resources concentrated into its relative small area. The vulnerability of
living resources and their habitats brought together French and British
maritime experts within a common project (called CHARM): to create an atlas
of marine resource habitats in the eastern English Channel so as to provide
planners and decision-makers with the necessary information to help managing
the use of its living and non-living resources. This multidisciplinary and
richly illustrated atlas provides abundant information on the legal
framework and physical environment; benthic invertebrates, fish and their
habitats; fishing activities; and a first attempt at developing a trophic
network model (using ECOPATH software) and a marine conservation planning
exercise (using MARXAN software, at a spatial resolution of 25 km
Although most of the data used were collected elsewhere, some were collected
especially for the project. Similarly, most of the analyses performed on the
data where entirely original for this geographical area. The CHARM atlas has
significantly improved the knowledge about the eastern Channel while
contributing to the recognition that such holistic or multidisciplinary
approaches to exploited marine systems are necessary to efficiently and
durably manage their resources use.
The availability of analytical methods that utilize the very intense and bright X-rays from synchrotron radiation sources has fundamentally changed the way in which geoscientists, environmental scientists and soil scientists study complex environmental samples and decipher the chemical and biological processes that impact the speciation, transport and potential bioavailability of environmental toxins (Brown et al., 2006). Such samples are often mixtures of crystalline and amorphous phases in particle-sizes ranging from cm to nm, adsorbed metal ions and organic molecules, natural organic matter, microbial organisms, algae, plant materials and aqueous solutions. The processes that affect the chemical forms and environmental fate of contaminants in such mixtures range from surface adsorption, desorption, precipitation and dissolution reactions, often involving a combination of hydrolysis, ligand exchange and electron transfer, to biological interactions in which microbial organisms, algae or plants interact with mineral surfaces and environmental contaminants.
Background: The local anaesthetic prilocaine has a low systemic toxicity mainly because of a high absorption in the lung and a large volume of distribution and thus is associated with a lower risk of neurological or cardiac side-effects. However, the major disadvantage is the formation of methaemoglobin by its metabolite o-toluidine. This prospective observational study was performed to identify factors that are associated with increased prilocaine-induced methaemoglobinaemia. Patients and methods: One Hundred and sixty two patients undergoing major knee surgery under general anaesthesia combined with peripheral nerve blocks (femoral nerve block, combined femoral/sciatic nerve block or lumbar plexus block) received a single bolus injection of 300 or 400 mg prilocaine about 30 min before surgery via a catheter. The proper placement was verified using nerve stimulation via a stimulating catheter. Three hours after prilocaine injection, venous blood samples were drawn and methaemoglobin levels were measured by standard photometric technique. Data was subjected to a stepwise multiple regression analysis. Results: The mean methaemoglobin for all patients was 2.7% (range: 0.9–15.4%). A higher dose of prilocaine and younger age were the most important predictive factors for higher methaemoglobin formation. Female sex and to a lesser extent the use of high-concentration/low-volume prilocaine also increased methaemoglobin levels. These four factors of the model explain 36% of the total variance. Other investigated factors, including the patient’s height, weight, body mass index, the site of catheter insertion, the anaesthetist’s judgement concerning the difficulty of catheter placement, duration of catheter placement or an inadvertent puncture of a venous or arterial vessel, had no significant impact on the concentration of methaemoglobin. Conclusion: The use of prilocaine for regional block is safe, since the older patients who might be more susceptible to suffer from clinical symptoms of methaemoglobinaemia usually form less methaemoglobin. However, since prediction of high methaemoglobin levels is difficult, anaesthesiologists performing regional blocks in patients who might be jeopardized by a decreased oxygen transport capacity should avoid high doses of prilocaine.