Critical properties of the Kitaev-Heisenberg model

We study critical properties of the Kitaev-Heisenberg model on the honeycomb lattice at finite temperatures which might describe the physics of the quasi two-dimensional compounds, Na$_2$IrO$_3$ and Li$_2$IrO$_3$. The model undergoes two phase transitions as a function of temperature. At low temperature, thermal fluctuations induce magnetic long-range order by order-by-disorder mechanism. Magnetically ordered state with the spontaneously broken $Z_6$ symmetry persists up to a certain critical temperature. We find that there is an intermediate phase between the low-temperature ordered phase and the high-temperature disordered phase. The finite-sized scaling analysis suggests that the intermediate phase is a critical Kosterlitz-Thouless phase with continuously variable exponents. We argue that the intermediate phase has been actually observed above the low-temperature magnetically ordered phase in Na$_2$IrO$_3$, and likely in Li$_2$IrO$_3$.Comment: 5 pages, 6 figure

Incidence of and risk factors for perineal trauma: A prospective observational study

Background: Our aim was to describe the range of perineal trauma in women with a singleton vaginal birth and estimate the effect of maternal and obstetric characteristics on the incidence of perineal tears. Methods: We conducted a prospective observational study on all women with a planned singleton vaginal delivery between May and September 2006 in one obstetric unit, three freestanding midwifery-led units and home settings in South East England. Data on maternal and obstetric characteristics were collected prospectively and analysed using univariable and multivariable logistic regression. The outcome measures were incidence of perineal trauma, type of perineal trauma and whether it was sutured or not. Results: The proportion of women with an intact perineum at delivery was 9.6% (125/1,302) in nulliparae, and 31.2% (453/1,452) in multiparae, with a higher incidence in the community (freestanding midwifery-led units and home settings). Multivariable analysis showed multiparity (OR 0.52; 95% CI: 0.30-0.90) was associated with reduced odds of obstetric anal sphincter injuries (OASIS), whilst forceps (OR 4.43; 95% CI: 2.02-9.71), longer duration of second stage of labour (OR 1.49; 95% CI: 1.13-1.98), and heavier birthweight (OR 1.001; 95% CI: 1.001-1.001), were associated with increased odds. Adjusted ORs for spontaneous perineal truama were: multiparity (OR 0.42; 95% CI: 0.32-0.56); hospital delivery (OR 1.48; 95% CI: 1.01-2.17); forceps delivery (OR 2.61; 95% CI: 1.22-5.56); longer duration of second stage labour (OR 1.45; 95% CI: 1.28-1.63); and heavier birthweight (OR 1.001; 95% CI: 1.000-1.001). Conclusions: This large prospective study found no evidence for an association between many factors related to midwifery practice such as use of a birthing pool, digital perineal stretching in the second stage, hands off delivery technique, or maternal birth position with incidence of OASIS or spontaneous perineal trauma. We also found a low overall incidence of OASIS, and fewer second degree tears were sutured in the community than in the hospital settings. This study confirms previous findings of overall high incidence of perineal trauma following vaginal delivery, and a strong association between forceps delivery and perineal trauma. © 2013 Smith et al; licensee BioMed Central Ltd

Regional scale mapping of grassland mowing frequency with Sentinel-2 time series

Grassland use intensity is a topic of growing interest worldwide, as grasslands are integral in supporting biodiversity, food production, and regulating of the global carbon cycle. Data available for characterizing grasslands management are largely descriptive and collected from laborious field campaigns or questionnaires. The recent launch of the Sentinel-2 earth monitoring constellation provides new possibilities for high temporal and spatial resolution remote sensing data covering large areas. This study aims to evaluate the potential of a time series of Sentinel-2 data for mapping of mowing frequency in the region of Canton Aargau, Switzerland. We tested two cloud masking processes and three spatial mapping units (pixels, parcel polygons and shrunken parcel polygons), and investigated how missing data influence the ability to accurately detect and map grassland management activity. We found that more than 40% of the study area was mown before 15 June, while the remaining part was either mown later, or was not mown at all. The highest accuracy for detection of mowing events was achieved using additional clouds masking and size reduction of parcels, which allowed correct detection of 77% of mowing events. Additionally, we found that using only standard cloud masking leads to significant overestimation of mowing events, and that the detection based on sparse time series does not fully correspond to key events in the grass growth season

Pulmonary artery acceleration time accuracy for systolic pulmonary artery pressure estimation in critically ill patients

Background: Estimation of pulmonary pressures is of key importance in acute cardiovascular and respiratory failure. Pulmonary artery acceleration time (PAAT) has emerged as reliable parameter for the estimation of systolic pulmonary artery pressure (sPAP) in cardiological population with preserved right ventricular function. We sought to find whether PAAT correlates with sPAP in critically ill patients with and without right ventricular (RV) systolic dysfunction.Methods: Observational study. We measured sPAP using continuous-wave Doppler analysis of tricuspid regurgitation velocity peak method and we assessed the validity of PAAT in estimating sPAP in patients admitted to adult intensive care unit (ICU) for acute cardiovascular and respiratory failure.Results: We enrolled 236 patients admitted to cardiothoracic ICU for cardiovascular and respiratory failure (respectively: 129, 54.7% and 107, 45.3%). 114 (48.3%) had preserved RV systolic function (defined as TAPSE >= 17 mm), whilst 122 (51.7%) had RV systolic impairment (defined as TAPSE < 17 mm). A weak inverse correlation between PAAT and sPAP (rho-0.189, p 0.0035) was observed in overall population, which was confirmed in those with preserved RV systolic PAAT and sPAP (rho-0.361, p 0.0001). In patients with impaired RV systolic function no statistically significant correlation between PAAT and sPAP was demonstrated (p 0.2737). Adjusting PAAT values for log(10), heart rate and RV ejection time did not modify the abovementioned correlations.Conclusions: PAAT measurement to derive sPAP is not reliable in cardiothoracic critically ill patients, particularly in the coexistence of RV systolic impairment

Legacies, socio-economic and biophysical processes and drivers : the case of future forest cover expansion in the Polish Carpathians and Swiss Alps

Mountain forest areas are key for providing a wide range of ecosystem services and are hot spots for land use change processes, in particular, increase in forest cover at the expense of mountain pastures and meadows. Mountain forest systems in eastern and western Europe have likely similar future socio-economic situations but significantly different socio-economic history. Using a scenario-based land use modelling approach (Dyna-CLUE framework) we model three scenarios (trend, liberalisation and self-sufficiency) of future land use in the Polish Carpathians and the Swiss Alps, focussing on forest cover change. We find that forest cover increase can be expected to continue in European mountainous regions under all likely scenarios, limited only by relatively strict policy interventions. Biophysical factors, rather than socio-eco- nomic ones, are key for defining the suitability for, and therefore likely locations of future forest cover, but land use legacy plays a very important role in the spatial pat- terns of future forest cover, particularly in eastern Europe

Complementary Therapies for Significant Dysfunction from Tinnitus: Treatment Review and Potential for Integrative Medicine

Tinnitus is a prevalent and costly chronic condition; no universally effective treatment exists. Only 20% of patients who report tinnitus actually seek treatment, and when treated, most patients commonly receive sound-based and educational (SBE) therapy. Additional treatment options are necessary, however, for nonauditory aspects of tinnitus (e.g., anxiety, depression, and significant interference with daily life) and when SBE therapy is inefficacious or inappropriate. This paper provides a comprehensive review of (1) conventional tinnitus treatments and (2) promising complementary therapies that have demonstrated some benefit for severe dysfunction from tinnitus. While there has been no systematic study of the benefits of an Integrative Medicine approach for severe tinnitus, the current paper reviews emerging evidence suggesting that synergistic combinations of complementary therapies provided within a whole-person framework may augment SBE therapy and empower patients to exert control over their tinnitus symptoms without the use of medications, expensive devices, or extended programs