Impact of calibration algorithms on hypoglycaemia detection in newborn infants using continuous glucose monitors

invited, 6-pagesNeonatal hypoglycaemia is a common condition that can cause seizures and serious brain injury in infants. It is diagnosed by blood glucose (BG) measurements, often taken several hours apart. Continuous glucose monitoring (CGM) devices can potentially improve hypoglycaemia detection, while reducing the number of BG measurements. Calibration algorithms convert the sensor signal into the CGM output. Thus, these algorithms can have a direct impact on measures used to quantify excursions from normal glycaemic levels. The aim of this study was to quantify the effects of calibration sensor error and non-linear filtering of CGM data on measures of hypoglycaemia (defined as BG < 2.6mmol/L) in neonates. CGM data was recalibrated using an algorithm that explicitly recognised the high accuracy of BG measurements available in this study. Median filtering was also implemented either before or after recalibration. Results for the entire cohort show an increase in the total number of hypoglycaemic events (161 to 193), duration of hypoglycaemia (2.2 to 2.6% of total data), and hypoglycaemic index (4.9 to 7.1µmol/L) after recalibration. With the addition of filtering, the number of hypoglycaemic events was reduced (193 to 131), with little or no change to the other metrics. These results show how reference sensor error and thus calibration algorithms play a significant role in quantifying hypoglycaemia. In particular, metrics such as counting the number of hypoglycaemic events were particularly sensitive to recalibration and filtering effects. While this conclusion might be expected, its potential impact is quantified here, in this case for at-risk neonates for whom hypoglycaemia carries potential long-term negative outcomes

Superluminal optical pulse propagation in nonlinear coherent media

The propagation of light-pulse with negative group-velocity in a nonlinear medium is studied theoretically. We show that the necessary conditions for these effects to be observable are realized in a three-level $\Lambda$-system interacting with a linearly polarized laser beam in the presence of a static magnetic field. In low power regime, when all other nonlinear processes are negligible, the light-induced Zeeman coherence cancels the resonant absorption of the medium almost completely, but preserves the dispersion anomalous and very high. As a result, a superluminal light pulse propagation can be observed in the sense that the peak of the transmitted pulse exits the medium before the peak of the incident pulse enters. There is no violation of causality and energy conservation. Moreover, the superluminal effects are prominently manifested in the reshaping of pulse, which is caused by the intensity-dependent pulse velocity. Unlike the shock wave formation in a nonlinear medium with normal dispersion, here, the self-steepening of the pulse trailing edge takes place due to the fact that the more intense parts of the pulse travel slower. The predicted effect can be easily observed in the well known schemes employed for studying of nonlinear magneto-optical rotation. The upper bound of sample length is found from the criterion that the pulse self-steepening and group-advance time are observable without pulse distortion caused by the group-velocity dispersion.Comment: 16 pages, 7 figure

The Kagome Antiferromagnet with Defects: Satisfaction, Frustration, and Spin Folding in a Random Spin System

It is shown that site disorder induces noncoplanar states, competing with the thermal selection of coplanar states, in the nearest neighbor, classical kagome Heisenberg antiferromagnet (AFM). For weak disorder, it is found that the ground state energy is the sum of energies of separately satisfied triangles of spins. This implies that disorder does not induce conventional spin glass behavior. A transformation is presented, mapping ground state spin configurations onto a folded triangular sheet (a new kind of ``spin origami'') which has conformations similar to those of tethered membranes.Comment: REVTEX, 11 pages + 3 pictures upon reques

Ergogenic and psychological effects of synchronous music during circuit-type exercise

This is the post print version of the article. The official published version can be obtained from the link below.Objectives: Motivational music when synchronized with movement has been found to improve performance in anaerobic and aerobic endurance tasks, although gender differences pertaining to the potential benefits of such music have seldom been investigated. The present study addresses the psychological and ergogenic effects of synchronous music during circuit-type exercise. Design: A mixed-model design was employed in which there was a within-subjects factor (two experimental conditions and a control) and a between-subjects factor (gender). Methods: Participants (N ¼ 26) performed six circuit-type exercises under each of three synchronous conditions: motivational music, motivationally-neutral (oudeterous) music, and a metronome control. Dependent measures comprised anaerobic endurance, which was assessed using the number of repetitions performed prior to the failure to maintain synchronicity, and post-task affect, which was assessed using Hardy and Rejeski’s (1989) Feeling Scale. Mixed-model 3 (Condition) X 2 (Gender) ANOVAs, ANCOVAs, and MANOVA were used to analyze the data. Results: Synchronous music did not elicit significant (p < .05) ergogenic or psychological effects in isolation; rather, significant (p < .05) Condition X Gender interaction effects emerged for both total repetitions and mean affect scores. Women and men showed differential affective responses to synchronous music and men responded more positively than women to metronomic regulation of their movements. Women derived the greatest overall benefit from both music conditions. Conclusions: Men may place greater emphasis on the metronomic regulation of movement than the remaining, extra-rhythmical, musical qualities. Men and women appear to exhibit differential responses in terms of affective responses to synchronous music

A Knob for Changing Light Propagation from Subluminal to Superluminal

We show how the application of a coupling field connecting the two lower metastable states of a lambda-system can produce a variety of new results on the propagation of a weak electromagnetic pulse. In principle the light propagation can be changed from subluminal to superluminal. The negative group index results from the regions of anomalous dispersion and gain in susceptibility.Comment: 6 pages,5 figures, typed in RevTeX, accepted in Phys. Rev.

Effects of Fluctuating Temperatures on Isowean Pigs

This study quantifies responses of isowean pigs (10 to 12 days of age, PIC breed) to potential in-transit temperature fluctuations for 54 h, followed by a 14-day growth period under thermoneutrality. The 54-h temperature regimens included a constant air temperature of 26.7°C (as control) and three cyclic air temperatures of 26.7 ± 2.8°C, 26.7 ± 5.6°C and 26.7 ± 8.3°C, all using woodshavings bedding atop rigid board insulation. The pigs received an average dosage of 0.91 kg/pig water replacement supply during the 54-h treatment period, and ad-libitum feeding and watering during the growth period. Pigs in all three treatments and the control had similar growth performance, physiological, and energetic responses during both treatment and growth periods. At the end of the treatment period, the pigs had elevated concentrations of hematocrit, plasma protein, blood urea nitrogen, sodium and chloride, but declined concentration of glucose (P \u3c 0.05). Potassium and bicarbonate levels remained relatively constant (P \u3e 0.05). Concentrations of the blood constituents returned to normal during the growth period. The results suggest that the isowean pigs respond well to air temperature fluctuations of up to ±8.3°C around the thermoneutral condition of 26.7°C air temperature coupled with woodshavings bedding

Doping Dependence of the Magnetic Resonance Peak in YBa_2 Cu_3 O_{6+x}

We report inelastic neutron scattering experiments on the doping dependence of the energy and spectral weight of the sharp magnetic resonance peak in YBa_2 Cu_3 O_{6+x}. These measurements also shed light on the relationship between the magnetic excitations in the normal and superconducting states.Comment: (mostly corrections to figures and minor change to caption in Fig.5) 5 figures. It will be published in the proceedings of M2S-HTSC-V. It needs the elsevier style file (not included) to convert to postscrip

Effects of Post-weaning Nutritional Conditions on Isowean Pigs

This study quantifies the responses of isowean pigs to post-weaning nutritional conditions as may be encountered during extended shipment. PIC breeding stock pigs at 8 to 12 days of age (3.5 to 4.0 kg body weight) were subjected to four nutritional regimens for 72 h. The pigs were then raised with ad libitum feeding for 14 days. Thermoneutral environments were used throughout the experiment. Pigs deprived of feed and water (i.e., Fast) had higher body weight loss (of 0.61 kg/pig or 17% of their initial body weight) as compared with pigs provided with feed and water supplement (0.39 kg/pig or 11% of their initial body weight) or water supplement only (0.43 kg/pig or 11.5% IBW) (P \u3c 0.05). All the treatments led to significant rise in blood urea nitrogen but fall in blood glucose (P \u3c 0.05). However, the glucose levels were much higher than the generally considered hypoglycemic level (75 mg/dL). All pigs showed a similar degree of dehydration, as evidenced by elevated hematocrit and blood electrolyte concentrations (P \u3c 0.05). The physiological responses returned to normal during the 14-day growth period and were similar for all the pigs. The results suggest that isowean pigs (PIC genetic line) responded well to post-weaning nutritional conditions typically encountered during extended shipments. Supply of bacteria-resistant water supplement such as Aqua-Jel seemed beneficial in reducing stress and may be considered for extended commercial shipment. However, in-transit supply of feed added little benefit to the pigs and thus may be omitted. This omission has special implications for international shipments because certain countries prohibit inclusion of feed in shipment. The energetics data of this study may be used to design and operate ventilation systems in transportation and production facilities for the isowean pigs

Nature of the Electronic Excitations near the Brillouin Zone Boundary of Bi2_2Sr2_2CaCu2_2O8+δ_{8+\delta}

Based on angle resolved photoemission spectra measured on different systems at different dopings, momenta and photon energies, we show that the anomalously large spectral linewidth in the $(\pi,0)$ region of optimal doped and underdoped Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ has significant contributions from the bilayer splitting, and that the scattering rate in this region is considerably smaller than previously estimated. This new picture of the electronic excitation near $(\pi,0)$ puts additional experimental constraints on various microscopic theories and data analysis.Comment: 5 pages, 4 figure