Remote sensing of seasonal light use efficiency in temperate bog ecosystems.

Despite storing approximately half of the atmosphere's carbon, estimates of fluxes between wetlands and atmosphere under current and future climates are associated with large uncertainties, and it remains a challenge to determine human impacts on the net greenhouse gas balance of wetlands at the global scale. In this study we demonstrate that the relationship between photochemical reflectance index, derived from high spectral and temporal multi-angular observations, and vegetation light use efficiency was strong (r2 = 0.64 and 0.58 at the hotspot and darkspot, respectively), and can be utilized to estimate carbon fluxes from remote at temperate bog ecosystems. These results improve our understanding of the interactions between vegetation physiology and spectral characteristics to understand seasonal magnitudes and variations in light use efficiency, opening new perspectives on the potential of this technique over extensive areas with different landcover.

Electroelastic hyperfine tuning of phosphorus donors in silicon.

We demonstrate an electroelastic control of the hyperfine interaction between nuclear and electronic spins opening an alternative way to address and couple spin-based qubits. The hyperfine interaction is measured by electrically detected magnetic resonance in phosphorus-doped silicon epitaxial layers employing a hybrid structure consisting of a silicon-germanium virtual substrate and a piezoelectric actuator. By applying a voltage to the actuator, the hyperfine interaction is changed by up to 0.9 MHz, which would be enough to shift the phosphorus donor electron spin out of resonance by more than one linewidth in isotopically purified 28Si.

The laryngeal tube: a new adjunct for airway management.

INTRODUCTION: A prototype of the laryngeal tube was tested for simple and reliable use for ventilation in a mannequin. One possible use of this tube will be the management of the difficult airway. In spite of blind insertion, an inadvertent tracheal positioning should not occur due to the form of the tube. A pharyngeal cuff provides a proximal seal of the airway, while an esophageal cuff seals the airway distally and prevents aspiration of gastric contents. A ventral opening between both cuffs is used for ventilation. OBJECTIVE: To examine the reliability of the laryngeal tube for airway management in a mannequin. METHODS: Fifty physicians and nurses were included in this study and inserted the laryngeal tube blindly during ten consecutive attempts in an advanced life support mannequin. All participants used the laryngeal tube for the first time. RESULTS: During 500 insertions of the tube, correct placement and sufficient ventilation were achieved 478 times in the first attempt (95.6%); 18 times (3.6%), inflating the proximal balloon with an additional 50 mL of air led to sufficient ventilation. In four attempts (0.8%), sufficient ventilation was still not possible due to the tube's not being placed deep enough (according to the printed ring marks on the tube). In each case, the tube was placed correctly in the following attempt. Neither a tracheal intubation nor ventilation of the stomach could be observed. The average time for positioning the laryngeal tube was 27.15 seconds for all 500 attempts (average time of the 50 participants for the tenth attempt: 23.85 seconds). CONCLUSION: The laryngeal tube may be a fast, reliable, and easy device for airway management. Further research is necessary.

Inverse intubation: an important alternative for intubation in the streets.

One of the highest priorities for prehospital emergency personnel is airway management. Several rescuer positions for intubation on the ground have been published. Only recently, the inverse intubation method as an additional approach for intubation in the out-of-hospital setting has received further attention. Using four case reports, situations in which inverse intubation may be an important tool for successful airway management are discussed. Other uses of the method are listed.

A randomized comparison of rescuer positions for intubation on the ground.

OBJECTIVE: To examine the ease of endotracheal intubation on the ground for various rescuer positions. METHODS: Six female and 18 male emergency medical technicians were asked to intubate a Laerdal Megacode Trainer placed on the ground. Rescuers assumed the following positions in random order: prone, sitting, kneeling at the mannequin's head, and straddling the chest. The authors measured times 1) for changing from mask ventilation to assuming intubation position and 2) from touching the laryngoscope to putting it down. Incidences of esophageal tube placement and clicks (possible tooth damage) were noted. The rescuers rated their satisfaction with each position on a six-point scale (1 = very good, 6 = insufficient). Total intubation times of the other three positions were compared with that for prone by rank order test for paired observations. Handling, esophageal positions, and clicks of the other three positions were compared with those for prone by sign test for paired observations. A Bonferroni correction (factor 12) was applied. RESULTS: Mean total intubation times (in seconds) were 11.8 +/- 3.3 for prone, 13.9 +/- 4.7 for sitting, 11.4 +/- 4.5 for kneeling, and 16.2 +/- 5.8 for straddling. The difference between straddling and prone was statistically significant (p < 0.005). For handling, the results were for prone 3.0 +/- 1.4, for sitting 3.1 +/- 1.1, for kneeling 2.2 +/- 0.6, and for straddling 2.8 +/- 1.4. Esophageal positions occurred for prone 1, for sitting 1, for kneeling 2, and for straddling 3. Clicks were counted for prone 2, for sitting 1, for kneeling 1, and for straddling 0. CONCLUSIONS: All tested positions provide satisfactory conditions for intubation on the ground. The straddling position requires statistically, but not clinically, significantly more time for intubation than does prone and may be an important backup position if access from behind the patient's head is impossible.

Nonemergency visits to a pediatric emergency department.

We examined six factors that may help to explain why parents take their children to hospital emergency departments: arrival time; travel time; who decided the patient should go; did the patient have a physician; did the parent attempt physician contact, and where the parent would have preferred to have gone for treatment. Results indicate that 47% of the nonemergency visits occurred during the time when physicians maintain office hours. Most visits were made by patients living less than 15 minutes away from the hospital. Physicians decided that the patient should go to the emergency department 18% of the time. Patients with a private physician accounted for 80% of the visits. Most parents did not try to contact a physician prior to the visit. Indeed, 46% of the parents preferred to take their children to the emergency department rather than to a physician's office. Finally, 74% of the parents who attempted some contact with a member of the health care system were referred to the emergengy department for care.