Magnetic Moment Formation in Graphene Detected by Scattering of Pure Spin Currents

Hydrogen adatoms are shown to generate magnetic moments inside single layer graphene. Spin transport measurements on graphene spin valves exhibit a dip in the non-local spin signal as a function of applied magnetic field, which is due to scattering (relaxation) of pure spin currents by exchange coupling to the magnetic moments. Furthermore, Hanle spin precession measurements indicate the presence of an exchange field generated by the magnetic moments. The entire experiment including spin transport is performed in an ultrahigh vacuum chamber, and the characteristic signatures of magnetic moment formation appear only after hydrogen adatoms are introduced. Lattice vacancies also demonstrate similar behavior indicating that the magnetic moment formation originates from pz-orbital defects.Comment: accepted to Phys. Rev. Let

Evaluating the quality of Douglas-fir (Pseudotsuga menziessii (Mirb.) Franco) seedlings : a comparison of some current and proposed evaluation methods

The physiological condition of tree seedlings at the time they are planted can have a profound impact on their subsequent field performance. Damaged or low vigor seedlings have a much greater chance of dying in the field, or at best, of growing slowly during their initial establishment period. Several methods of evaluating the physiological quality of seedlings are currently used to try to predict how seedlings will perform after outplanting. The root growth potential (RGP) approach measures the ability of seedlings to initiate and elongate roots when placed in an environment favorable to root growth. The vigor method, or test, monitors the survival and bud burst of potted seedlings in a growthstimulating environment. While both methods reportedly provide a general indication of seedling health or vigor, the effectiveness of these techniques in actually predicting field survival and height growth of Douglas-fir [Pseudotsuqa menziesii (Mirb.) Franca] seedlings has either not been sufficiently documented, or there have been inconsistent results. A primary goal of this research was to evaluate and compare how well these methods predict growth and survival of Douglasfir seedlings. Another goal was to examine two new, more rapid, methods of evaluating seedling quality and determine how effective they are. The first of these, called the PMS method, monitors changes in plant moisture stress (PMS) of potted seedlings during a one-week interval in the growth room. The second method measures the root respiration rate of seedlings to determine if changes in seedling quality are reflected in altered root respiratory activities. Results from these studies indicated that measurements from both the RGP and vigor method were significantly correlated with first- and second-year survival and height growth for two Douglas-fir seed sources planted on a variety of sites. For RGP, the best predictor of field performance was the number of new roots greater than 0.5 cm produced during 28 days in the growth room. For the vigor method, the survival of both stressed and unstressed seedlings after 6 weeks in the growth room were the best predictors. Seedlings from lots that produced more new roots, or had higher growth room survival, also had higher field survival and greater growth. The RGP procedure was the best predictor of seedling terminal height growth, while the vigor method was the best predictor of field survival. When these procedures were used in conjunction, correlations with field performance variables improved slightly, but not enough to justify the time and expense of using both. Measurements of plant moisture stress were found to reliably predict damage to seedlings caused by accidental freezing. In addition, this pressure chamber method predicted reductions in field survival and growth caused from several other types of injury. In contrast, root respiration measurements were not consistently related to growth-room survival or growth and this approach does not appear promising as an effective evaluation procedure

Photoperiodic responses of Douglas-fir (Pseudotsuga Menziesii (Mirb.) Franco) and Ponderosa pine (Pinus ponderosa) seedlings

An important cultural tool in the greenhouse production of tree seedlings in the Pacific Northwest is the control of photoperiod. By artificially lengthening the period of daily exposure to light, it is possible to increase both the magnitude and duration of seedling growth. By shortening the photoperiod, one can induce dormancy and hasten the development of frost hardiness, A variety of supplemental lighting and light blocking techniques are currently used in the production of Douglas-fir and ponderosa pine seedlings. However, there is little information on the relative advantages of alternative lighting and light blocking schemes in terms of biological benefits or production costs. Three experiments were therefore conducted to investigate the effects of a variety of photoperiodic regimes on controlling the growth, dormancy and frost hardiness of seedlings of these two species. The objectives of these experiments were to determine the following: 1) the minimum light intensity, of an eight-hour period of supplemental light, capable of delaying dormancy and increasing the vegetative growth of newly germinated seedlings in the fall; 2) the effects of a variety of nighttime lighting treatments on maintaining seedlings in an actively growing condition in the early spring; and 3) the effects of varying daylengths and varying intensities of light leakage on the development of frost hardiness of seedlings in the late summer and early fall. In all three experiments there were pronounced differences between the responses of Douglas-fir seedlings and those of ponderosa pine seedlings. For Douglas-fir seedlings, an eight-hour period of supplemental lighting delayed dormancy and increased both stem elongation and dry weight when the intensity of the light provided was ten or more foot candles. Intensities of one foot candle or less did not cause any increase in the magnitude or duration of seedling growth. A variety of nighttime lighting regimes, including several intermittent lighting treatments, a two-hour night break, and 16- and 22-hour photoperiods, successfully extended the period of active growth of newly germinated winter-sown seedlings. Finally, shortening the photoperiod in the late summer and early fall substantially increased the frost hardiness of seedlings, but relatively low intensities of light leakage reduced seedling hardiness. For ponderosa pine seedlings, there was no obvious threshold supplemental light intensity above which dormancy was delayed and below which it was induced. Ten foot candles or more resulted in an increase in height growth, but there was no consistent relationship between light intensity and dry weight, bud set or basal diameter. For pine seedlings in the second experiment, growth was greatest for those exposed to only a natural photoperiod. Lastly, shortening the photoperiod in the late summer and early fall resulted in a general decrease in the level of frost hardiness developed in ponderosa pine seedlings. These results suggest that the control of photoperiod can be a highly effective tool for regulating the annual growth cycle of Douglas-fir seedlings, but is relatively ineffective for ponderosa pine seedlings

Microstream capnography during conscious sedation with midazolam for oral surgery: a randomised controlled trial.

Objectives/Aims: There has been no dentistry-specific published data supporting the use of monitoring with capnography for dental sedation. Our aim was to determine if adding capnography to standard monitoring during conscious sedation with midazolam would decrease the incidence of hypoxaemia. Materials and Methods: A randomised controlled trial was conducted in which all patients (ASA I and II) received standard monitoring and capnography, but were randomised to whether staff could view the capnography (intervention) or were blinded to it (control). The primary outcome was the incidence of hypoxaemia (SpO2⩽94%). Results: We enrolled 190 patients, mean age 31 years (range, 14–62 years). There were 93 patients in the capnography group and 97 in the control group. The mean cumulative dose of midazolam titrated was 6.94 mg (s.d., 2.31; range, 3–20 mg). Six (3%) patients, three in each group, required temporary supplemental oxygen. There was no statistically significant difference between the capnography and control groups for the incidence of hypoxaemia: 34.4 vs 39.2% (P=0.4962, OR=0.81, 95% CI: 0.45–1.47). Conclusions: We were unable to confirm an additive role for capnography to prevent hypoxaemia during conscious sedation with midazolam for patients not routinely administered supplemental oxygen

Stem Cell Interventions for Bone Healing: Fractures and Osteoporosis

With the ageing population, musculoskeletal conditions are becoming more inherent. Delayed union is defined as a slower than normal fracture healing response, with no healing after 4 to 6 months; however, union is anticipated given sufficient time. In the context of delayed/non-union, fragility fractures in osteoporotic populations carry significant patient morbidity and socioeconomic costs. Multiple mechanisms hinder fracture healing in osteoporotic patients, imbalanced bone remodelling leads to impaired bone microarchitecture due to reduced osteoblast number and activity and as such, callus formation is diminished. Since stem cells can self-renew and differentiate into various tissue lineages, they are becoming very popular in tissue regeneration in musculoskeletal conditions. In this review we discuss the role of stem cells in physiological fracture healing and their potential therapeutic use following a fracture. We explore the potential of stem cells, the release of chemokines and cytokines to reduce fracture risk in osteoporosis

A rapid turnaround gene panel for severe autoinflammation: Genetic results within 48 hours

There is an important unmet clinical need for fast turnaround next generation sequencing (NGS) to aid genetic diagnosis of patients with acute and sometimes catastrophic inflammatory presentations. This is imperative for patients who require precise and targeted treatment to prevent irreparable organ damage or even death. Acute and severe hyper- inflammation may be caused by primary immunodeficiency (PID) with immune dysregulation, or more typical autoinflammatory diseases in the absence of obvious immunodeficiency. Infectious triggers may be present in either immunodeficiency or autoinflammation. We compiled a list of 25 genes causing monogenetic immunological diseases that are notorious for their acute first presentation with fulminant inflammation and which may be amenable to specific treatment, including hemophagocytic lymphohistiocytosis (HLH); and autoinflammatory diseases that can present with early-onset stroke or other irreversible neurological inflammatory complications. We designed and validated a pipeline that enabled return of clinically actionable results in hours rather than weeks: the Rapid Autoinflammation Panel (RAP). We demonstrated accuracy of this new pipeline, with 100% sensitivity and 100% specificity. Return of results to clinicians was achieved within 48-hours from receiving the patient's blood or saliva sample. This approach demonstrates the potential significant diagnostic impact of NGS in acute medicine to facilitate precision medicine and save "life or limb" in these critical situations

Equatorial adjusment in the Eastern Atlantic

Observations suggest that the annual upwelling event in the Gulf of Guinea is not associated with changes in the local winds. A possible explanation is that a strong upwelling signal, generated by increased westward wind stress in the Western Atlantic as an equatorially trapped Kelvin wave. This explanation is analogous to current theories of El Nino in the Pacific Ocean. (Résumé d'auteur

Blockade of nucleus accumbens 5-HT2A and 5-HT2C receptors prevents the expression of cocaine-induced behavioral and neurochemical sensitization in rats

The serotonin 5-HT2A and 5-HT2C receptors regulate the capacity of acute cocaine to augment behavior and monoamine levels within the nucleus accumbens (NAC), a brain region involved in cocaine’s addictive and psychotogenic properties. In the present study, we tested the hypothesis that NAC 5-HT2A and 5-HT2C receptor activation is involved in the expression of cocaine-induced neuroplasticity following protracted withdrawal from a sensitizing repeated cocaine regimen (days 1 and 7, 15 mg/kg; days 2–6, 30 mg/kg, i.p.). The effects of intra-NAC infusions of the 5-HT2A antagonist R-(+)-α-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenylethyl)]-4-piperidine methanol (MDL 100907; 0, 50, 100, 500 nM) or the 5-HT2C antagonist [6-chloro-5-methyl-1-(6-(2-methylpiridin-3-yloxy)pyridine-3-yl carbamoyl] inodoline dihydrochloride (SB 242084; 0, 50, 100, 500 nM) were first assessed upon the expression of locomotor activity elicited by a 15-mg/kg cocaine challenge injection administered at 3-week withdrawal. A follow-up in vivo microdialysis experiment then compared the effects of the local perfusion of 0, 50, or 100 nM of each antagonist upon cocaine-induced dopamine and glutamate sensitization in the NAC. Although neither MDL 100907 nor SB 242084 altered acute cocaine-induced locomotion, SB 242084 reduced acute cocaine-elevated NAC dopamine and glutamate levels. Intra-NAC perfusion with either compound blocked the expression of cocaine-induced locomotor and glutamate sensitization, but only MDL 100907 pretreatment prevented the expression of cocaine-induced dopamine sensitization. These data provide the first evidence that NAC 5-HT2A and 5-HT2C receptors are critical for the expression of cocaine-induced neuroplasticity following protracted withdrawal, which has relevance for their therapeutic utility in the treatment of addiction