Detection and Quantification of Snow Algae with an Airborne Imaging Spectrometer

We describe spectral reflectance measurements of snow containing the snow alga Chlamydomonas nivalis and a model to retrieve snow algal concentrations from airborne imaging spectrometer data. Because cells of C. nivalis absorb at specific wavelengths in regions indicative of carotenoids (astaxanthin esters, lutein, β-carotene) and chlorophylls a and b, the spectral signature of snow containing C. nivalis is distinct from that of snow without algae. The spectral reflectance of snow containing C. nivalis is separable from that of snow without algae due to carotenoid absorption in the wavelength range from 0.4 to 0.58 μm and chlorophyll a and b absorption in the wavelength range from 0.6 to 0.7 μm. The integral of the scaled chlorophyll a and b absorption feature (I_0.68) varies with algal concentration (C_a). Using the relationship C_a = 81019.2 I_0.68 + 845.2, we inverted Airborne Visible Infrared Imaging Spectrometer reflectance data collected in the Tioga Pass region of the Sierra Nevada in California to determine algal concentration. For the 5.5-km² region imaged, the mean algal concentration was 1,306 cells ml⁻¹, the standard deviation was 1,740 cells ml⁻¹, and the coefficient of variation was 1.33. The retrieved spatial distribution was consistent with observations made in the field. From the spatial estimates of algal concentration, we calculated a total imaged algal biomass of 16.55 kg for the 0.495-km² snow-covered area, which gave an areal biomass concentration of 0.033 g/m².     

Effect of Resistive Load on the Inspiratory Work and Power of Breathing during Exertion

The resistive work of breathing against an external load during inspiration (WR_I) was measured at the mouth, during sub-maximal exercise in healthy participants. This measure (which excludes the elastic work component) allows the relationship between resistive work and power, ventilation and exercise modality to be explored. A total of 45 adult participants with healthy lung function took part in a series of exercise protocols, in which the relationship between WR_I, power of breathing, PR_I and minute ventilation, were assessed during rest, while treadmill walking or ergometer cycling, over a range of exercise intensities (up to 150 Watts) and ventilation rates (up to 48 L min⁻¹) with applied constant resistive loads of 0.75 and 1.5 kPa.L.sec⁻¹. Resting WR_I was 0.12 JL⁻¹ and PR_I was 0.9 W. At each resistive load, independent of the breathing pattern or exercise mode, the WR_I increased in a linear fashion at 20 mJ per litre of , while PR_I increased exponentially. With increasing resistive load the work and power at any given increased exponentially. Calculation of the power to work ratio during loaded breathing suggests that loads above 1.5 kPa.L.sec⁻¹ make the work of resistive breathing become inhibitive at even a moderate (>30 L sec⁻¹). The relationship between work done and power generated while breathing against resistive loads is independent of the exercise mode (cycling or walking) and that ventilation is limited by the work required to breathe, rather than an inability to maintain or generate power.     

Arginine methylation in subunits of mammalian pre-mRNA cleavage factor I

Mammalian cleavage factor I (CF I_m) is composed of two polypeptides of 25 kDa and either a 59 or 68 kDa subunit (CF I_m25, CF I_m59, CF I_m68). It is part of the cleavage and polyadenylation complex responsible for processing the 3′ ends of messenger RNA precursors. To investigate post-translational modifications in factors of the 3′ processing complex, we systematically searched for enzymes that modify arginines by the addition of methyl groups. Protein arginine methyltransferases (PRMTs) are such enzymes that transfer methyl groups from S-adenosyl methionine to arginine residues within polypeptide chains resulting in mono- or dimethylated arginines. We found that CF I_m68 and the nuclear poly(A) binding protein 1 (PABPN1) were methylated by HeLa cell extracts in vitro. By fractionation of these extracts followed by mass spectral analysis, we could demonstrate that the catalytic subunit PRMT5, together with its cofactor WD45, could symmetrically dimethylate CF I_m68, whereas pICln, the third polypeptide of the complex, was stimulatory. As sites of methylation in CF I_m68 we could exclusively identify arginines in a GGRGRGRF or “GAR” motif that is conserved in vertebrates. Further in vitro assays revealed a second methyltransferase, PRMT1, which modifies CF I_m68 by asymmetric dimethylation of the GAR motif and also weakly methylates the C-termini of both CF I_m59 and CF I_m68. The results suggest that native—as compared with recombinant—protein substrates may contain additional determinants for methylation by specific PRMTs. A possible involvement of CF I_m methylation in the context of RNA export is discussed.     

Exposure to a combination of heat and hyperoxia during cycling at submaximal intensity does not alter thermoregulatory responses

In this study, we tested the hypothesis that breathing hyperoxic air (F_inO₂ = 0.40) while exercising in a hot environment exerts negative effects on the total tissue level of haemoglobin concentration (tHb); core (T_core) and skin (T_skin) temperatures; muscle activity; heart rate; blood concentration of lactate; pH; partial pressure of oxygen (P_aO₂) and carbon dioxide; arterial oxygen saturation (S_aO₂); and perceptual responses. Ten well-trained male athletes cycled at submaximal intensity at 21°C or 33°C in randomized order: first for 20 min while breathing normal air (F_inO₂ = 0.21) and then 10 min with F_inO₂ = 0.40 (HOX). At both temperatures, S_aO₂ and P_aO₂, but not tHb, were increased by HOX. Tskin and perception of exertion and thermal discomfort were higher at 33°C than 21°C (p < 0.01), but independent of F_inO₂. T_core and muscle activity were the same under all conditions (p > 0.07). Blood lactate and heart rate were higher at 33°C than 21°C. In conclusion, during 30 min of submaximal cycling at 21°C or 33°C, T_core, T_skin and T_body, tHb, muscle activity and ratings of perceived exertion and thermal discomfort were the same under normoxic and hyperoxic conditions. Accordingly, breathing hyperoxic air (F_inO₂ = 0.40) did not affect thermoregulation under these conditions.     

Oxygen Transport in Acute Pulmonary Oedema and in Acute Exacerbations of Chronic Bronchitis

When breathing air, the average arterial oxygen tension in eight patients with acute pulmonary oedema was significantly higher than in eight other patients suffering from an acute exacerbation of chronic bronchitis, but the mixed venous oxygen tension was very similar in both groups. This largely arose from the smaller arteriovenous difference of oxygen content in the bronchitic cases, presumably due to their higher cardiac output, associated with raised arterial CO₂ tensions. Oxygen therapy (60-90% for pulmonary oedema, 30% for the bronchitics) raised the mixed venous oxygen tensions to a similar level in both groups. We suggest that the major need for oxygen therapy lies in patients who maintain their oxygen consumption but show a reduction in mixed venous tension when breathing air. Although partial correction of arterial hypoxaemia is adequate in chronic bronchitis—in which the cardiac output is maintained—high concentrations of oxygen are necessary in pulmonary oedema, in which the cardiac output is low.     

Air Breathing and Gill Ventilation Frequencies in Juvenile Tarpon, Megalops atlanticus: Responses to Changes in Dissolved Oxygen, Temperature, Hydrogen Sulfide, and PH

This study quantified the air-breathing frequency (ABf in breaths h^–1) and gill ventilation frequency (Vf in ventilations min^–1) of tarpon Megalops atlanticusas a function of PO₂, temperature, pH, and sulphide concentration. Ten tarpon held at normoxia at 22–33°C without access to atmospheric oxygen survived for eight days, and seven survived for 14 days (at which point the experiment was terminated) suggesting that the species is a facultative, rather than an obligate, air breather. At temperatures of 29°C and below ABf was highest and Vf was lowest at low oxygen partial pressures. Tarpon appear to switch from aquatic respiration to air breathing at PO₂levels of roughly 40 torr. The gills were the primary organ for oxygen uptake in normoxia, and the air-breathing organ the primary mechanism for oxygen uptake in hypoxia. At 33°C, both ABf and Vf were elevated but highly variable, regardless of PO₂. There were no mortalities in tarpon exposed to total H₂S concentrations of 0–232µM (0–150.9µM H₂S); however, high sulfide concentrations resulted in very high ABf and Vf near zero. Vf was reduced when pH was acidic. We conclude that air breathing provides an effective means of coping with the environmental conditions that characterize the eutrophic ponds and sloughs that juvenile tarpon typically inhabit.     

Resonance Raman Studies of Co—O2 and O—O Stretching Vibrations in Oxy-Cobalt Hemes

Strong evidence suggests that the stretching vibration of the bound oxygen can be perturbed by an accidentally degenerate porphyrin ring mode, resulting in two split frequencies. In the Co(II)(TpivPP) (pyridine) ¹⁸O₂ complex, we demonstrate that the ν(¹⁸O—¹⁸O) mode, after being shifted from its ν(¹⁶O—¹⁶O) value at 1,156 cm^-1, undergoes a resonance interaction with the 1,080 cm^-1 porphyrin mode, giving rise to two lines at 1,067 and 1,089 cm^-1. In the O₂ complex of Co(II) mesoporphyrin IX-substituted sperm whale myoglobin, we observed a dramatic intensity increase at 1,132 cm^-1 upon ¹⁶O₂ → ¹⁸O₂ substitution, which is due to the reappearance of the 1,132-cm^-1 porphyrin mode after the removal of resonance conditions. A decrease in O₂ binding affinity, caused by the proximal base tension, corresponds to an increase in the Co—O₂ stretching frequency. The ν(Co—O₂) at 527 cm^-1 for the low affinity Co(II)(TpivPP)(1,2-Me₂Im) O₂ complex is 11 cm^-1 higher than the 516-cm^-1 value for the high affinity complex (with N-MeIm replacing 1,2-Me₂Im). However, in the corresponding iron complexes the reverse behavior is observed, i.e., the ν(Fe—O₂) decreases for the (1,2-Me₂Im) complex. There is a 24-cm^-1 difference in the Co—O₂ stretching frequencies between Co(II)(TpivPP)(N-MeIm)O₂ (at 516 cm^-1) and oxy meso CoMb (at 540 cm^-1), suggesting a protein induced distortion of the Co—O—O linkage. However, the values for ν(Fe—O₂) are nearly identical between Fe(II)(TpivPP)(N-MeIm)O₂ (at 571 cm^-1) and oxy Mb (at 573 cm^-1), indicating that O₂ binds to myoglobin in the same manner as in the sterically unhindered “picket fence” complex. Evidence is presented that suggests the presence of two dioxygen stretching frequencies due to two different conformers in each of the N-MeIm and 1,2-Me₂Im complex of oxy Co(II)(TpivPP).     

Comparison of avalanche survival patterns in Canada and Switzerland

Background

Current recommendations for rescue and resuscitation of people buried in avalanches are based on Swiss avalanche survival data. We analyzed Canadian survival patterns and compared them with those from Switzerland.

Methods

We extracted relevant data for survivors and nonsurvivors of complete avalanche burials from Oct. 1, 1980, to Sept. 30, 2005, from Canadian and Swiss databases. We calculated survival curves for Canada with and without trauma-related deaths as well as for different outdoor activities and snow climates. We compared these curves with the Swiss survival curve.

Results

A total of 301 people in the Canadian database and 946 in the Swiss database met the inclusion criteria. The overall proportion of people who survived did not differ significantly between the two countries (46.2% [139/301] v. 46.9% [444/946]; p = 0.87). Significant differences were observed between the overall survival curves for the two countries (p = 0.001): compared with the Swiss curve, the Canadian curve showed a quicker drop at the early stages of burial and poorer survival associated with prolonged burial. The probability of survival fell quicker with trauma-related deaths and in denser snow climates. Poorer survival probabilities in the Canadian sample were offset by significantly quicker extrication (median duration of burial 18 minutes v. 35 minutes in the Swiss sample; p < 0.001).

Interpretation

Observed differences in avalanche survival curves between the Canadian and Swiss samples were associated with the prevalence of trauma and differences in snow climate. Although avoidance of avalanches remains paramount for survival, the earlier onset of asphyxia, especially in maritime snow climates, emphasizes the importance of prompt extrication, ideally within 10 minutes. Protective devices against trauma and better clinical skills in organized rescue may further improve survival.A valanches make winter outdoor travel in mountainous terrain a hazardous activity. A total of 881 people died from avalanches in open terrain in Europe and North America over the six winters from 2003/04 to 2008/09.¹ The survival pattern of complete avalanche burials (coverage of the person’s head and chest, impairing breathing) in open terrain in Europe has been depicted in the avalanche survival curve,^2,3 which displays probability of survival as a function of burial time. The curve exhibits a characteristic shape, with four distinct phases. The probability of survival remains above 91% during the first 18 minutes of burial (“survival phase”). This phase is followed by a precipitous drop to 34% between 19 and 35 minutes because of asphyxiation of most people (“asphyxia phase”). Between 35 and 90 minutes, the survival curve levels out (“latent phase”) because of the survival of people with patent airways.⁴ Thereafter, survival drops again as those buried eventually succumb to lethal hypothermia complicated by progressive hypoxia and hypercapnia.⁵This avalanche survival model forms the foundation for current international recommendations for rescue and resuscitation^3,4 as well as the rationale for safety and rescue devices.⁶ However, the existing survival curve was calculated solely from Swiss data. Therefore, the universal validity of the survival curve and recommendations derived from it remains unknown.We analyzed survival curves for Canada and compared them with the survival curve in Switzerland. A better understanding of the factors affecting survival during an avalanche burial will provide important background for improvements in rescue, resuscitation and avalanche safety measures in Canada and elsewhere.     

Snow melt stimulates ecosystem respiration in Arctic ecosystems

Cold seasons in Arctic ecosystems are increasingly important to the annual carbon balance of these vulnerable ecosystems. Arctic winters are largely harsh and inaccessible leading historic data gaps during that time. Until recently, cold seasons have been assumed to have negligible impacts on the annual carbon balance but as data coverage increases and the Arctic warms, the cold season has been shown to account for over half of annual methane (CH₄) emissions and can offset summer photosynthetic carbon dioxide (CO₂) uptake. Freeze–thaw cycle dynamics play a critical role in controlling cold season CO₂ and CH₄ loss, but the relationship has not been extensively studied. Here, we analyze freeze–thaw processes through in situ CO₂ and CH₄ fluxes in conjunction with soil cores for physical structure and porewater samples for redox biogeochemistry. We find a movement of water toward freezing fronts in soil cores, leaving air spaces in soils, which allows for rapid infiltration of oxygen‐rich snow melt in spring as shown by oxidized iron in porewater. The snow melt period coincides with rising ecosystem respiration and can offset up to 41% of the summer CO₂ uptake. Our study highlights this important seasonal process and shows spring greenhouse gas emissions are largely due to production from respiration instead of only bursts of stored gases. Further warming is projected to result in increases of snowpack and deeper thaws, which could increase this ecosystem respiration dominate snow melt period causing larger greenhouse gas losses during spring.     

Determinants of Beat-to-Beat Variability of Repolarization Duration in the Canine Ventricular Myocyte: A Computational Analysis

Beat-to-beat variability of repolarization duration (BVR) is an intrinsic characteristic of cardiac function and a better marker of proarrhythmia than repolarization prolongation alone. The ionic mechanisms underlying baseline BVR in physiological conditions, its rate dependence, and the factors contributing to increased BVR in pathologies remain incompletely understood. Here, we employed computer modeling to provide novel insights into the subcellular mechanisms of BVR under physiological conditions and during simulated drug-induced repolarization prolongation, mimicking long-QT syndromes type 1, 2, and 3. We developed stochastic implementations of 13 major ionic currents and fluxes in a model of canine ventricular-myocyte electrophysiology. Combined stochastic gating of these components resulted in short- and long-term variability, consistent with experimental data from isolated canine ventricular myocytes. The model indicated that the magnitude of stochastic fluctuations is rate dependent due to the rate dependence of action-potential (AP) duration (APD). This process (the “active” component) and the intrinsic nonlinear relationship between membrane current and APD (“intrinsic component”) contribute to the rate dependence of BVR. We identified a major role in physiological BVR for stochastic gating of the persistent Na⁺ current (I_Na) and rapidly activating delayed-rectifier K⁺ current (I_Kr). Inhibition of I_Kr or augmentation of I_Na significantly increased BVR, whereas subsequent β-adrenergic receptor stimulation reduced it, similar to experimental findings in isolated myocytes. In contrast, β-adrenergic stimulation increased BVR in simulated long-QT syndrome type 1. In addition to stochastic channel gating, AP morphology, APD, and beat-to-beat variations in Ca²⁺ were found to modulate single-cell BVR. Cell-to-cell coupling decreased BVR and this was more pronounced when a model cell with increased BVR was coupled to a model cell with normal BVR. In conclusion, our results provide new insights into the ionic mechanisms underlying BVR and suggest that BVR reflects multiple potentially proarrhythmic parameters, including increased ion-channel stochasticity, prolonged APD, and abnormal Ca²⁺ handling.     

Bimodal oxygen uptake in juveniles and adults amphibious fish,Channa (= Ophiocephalus) marulius

Oxygen uptake of Channa marulius was studied under water with and without access to air. There was a significant increase in the oxygen uptake through the gills when access to air was prevented. However, this value (0.863 ± 0.058 mlO₂/indiv./h) was quite low in comparison to the total bimodal oxygen uptake (2.04 ± 0.14 mlO₂/indiv./h) in juveniles. In adult fish the oxygen uptake per unit time increased appreciably (4.673 ± 0.404 mlO₂/indiv./h). In juveniles as well as in adults the air breathing dominated over aquatic breathing. This fish showed a definite circadian rhythm in the bimodal oxygen uptake during different hours of the day.This work was performed in the Ichthyology Laboratory, P. G. Dept. of Zoology, Bhagalpur University, and was supported by a research grant from Bhagalpur University     

Effect of Controlled Oxygen Therapy on Arterial Blood Gases in Acute Respiratory Failure

Seven patients in acute exacerbation of chronic respiratory failure were given 24·5% and later 28% oxygen through Ventimasks. The mean increases in arterial PO₂ were 11 and 21 mm. Hg while breathing 24·5% and 28% oxygen respectively compared with control values while breathing air. Associated increases in arterial PCO₂ were 4 and 8 mm. Hg, respectively. In five of the patients these increases in inspired oxygen concentration resulted in useful increases in tissue oxygen supply without significant deterioration in ventilation, but in two patients arterial PCO₂ rose excessively and artificial ventilation was required.     

Complete Atrial-Specific Knockout of Sodium-Calcium Exchange Eliminates Sinoatrial Node Pacemaker Activity

The origin of sinoatrial node (SAN) pacemaker activity in the heart is controversial. The leading candidates are diastolic depolarization by “funny” current (I_f) through HCN4 channels (the “Membrane Clock“ hypothesis), depolarization by cardiac Na-Ca exchange (NCX1) in response to intracellular Ca cycling (the "Calcium Clock" hypothesis), and a combination of the two (“Coupled Clock”). To address this controversy, we used Cre/loxP technology to generate atrial-specific NCX1 KO mice. NCX1 protein was undetectable in KO atrial tissue, including the SAN. Surface ECG and intracardiac electrograms showed no atrial depolarization and a slow junctional escape rhythm in KO that responded appropriately to β-adrenergic and muscarinic stimulation. Although KO atria were quiescent they could be stimulated by external pacing suggesting that electrical coupling between cells remained intact. Despite normal electrophysiological properties of I_f in isolated patch clamped KO SAN cells, pacemaker activity was absent. Recurring Ca sparks were present in all KO SAN cells, suggesting that Ca cycling persists but is uncoupled from the sarcolemma. We conclude that NCX1 is required for normal pacemaker activity in murine SAN.     

Energetics of Sodium Transport in Frog Skin : II. The effects of electrical potential on oxygen consumption

Studies were made of the dependence of the rate of oxygen consumption, J_r, on the electrical potential difference, Δψ, across the frog skin. After the abolition of sodium transport by ouabain the basal oxygen consumption was independent of Δψ. In fresh skins J_r was a linear function of Δψ over a range of at least ±70 mv. Treatment with aldosterone stimulated the short-circuit current, I_o, and the associated rate of oxygen consumption, J_ro, and increased their stability; linearity was then demonstrable over a range of ±160 mv. Brief perturbations of Δψ (±30–200 mv) did not alter subsequent values of I_o. Perturbations for 10 min or more produced a "memory" effect both with and without aldosterone: accelerating sodium transport by negative clamping lowered the subsequent value of I_o; positive clamping induced the opposite effect. Changes in J_ro were more readily detectable in the presence of aldosterone; these were in the same direction as the changes in I_o. The linearity of J_r in Δψ indicates the validity of analysis in terms of linear nonequilibrium thermodynamics—brief perturbations of Δψ appear to produce no significant effect on either the phenomenological coefficients or the free energy of the metabolic driving reaction. Hence it is possible to evaluate this free energy.     

Are We Biologically Safe with Snow Precipitation? A Case Study in Beijing

In this study, the bacterial and fungal abundances, diversities, conductance levels as well as total organic carbon (TOC) were investigated in the snow samples collected from five different snow occurrences in Beijing between January and March, 2010. The collected snow samples were melted and cultured at three different temperatures (4, 26 and 37°C). The culturable bacterial concentrations were manually counted and the resulting colony forming units (CFUs) at 26°C were further studied using V3 region of 16 S rRNA gene-targeted polymerase chain reaction -denaturing gradient gel electrophoresis (PCR-DGGE). The clone library was constructed after the liquid culturing of snow samples at 26°C. And microscopic method was employed to investigate the fungal diversity in the samples. In addition, outdoor air samples were also collected using mixed cellulose ester (MCE) filters and compared with snow samples with respect to described characteristics. The results revealed that snow samples had bacterial concentrations as much as 16000 CFU/ml for those cultured at 26°C, and the conductance levels ranged from 5.6×10⁻⁶ to 2.4×10⁻⁵ S. PCR-DGGE, sequencing and microscopic analysis revealed remarkable bacterial and fungal diversity differences between the snow samples and the outdoor air samples. In addition, DGGE banding profiles for the snow samples collected were also shown distinctly different from one another. Absent from the outdoor air, certain human, plant, and insect fungal pathogens were found in the snow samples. By calculation, culturable bacteria accounted for an average of 3.38% (±1.96%) of TOC for the snow samples, and 0.01% for that of outdoor air samples. The results here suggest that snow precipitations are important sources of fungal pathogens and ice nucleators, thus could affect local climate, human health and agriculture security.     

The emergence of endothermy in the black-footed and Laysan albatrosses

Eggs with pip-holes of the black-footed (Diomedea nigripes) and Laysan (Diomedea immutabilis) albatrosses were exposed to various air temperatures in the range 20–35°C in order to detect signs of incipient endothermy in late embryos. No evidence of endothermy was found. In contrast, the O₂ consumption of most hatchlings increased in response to cooling, the O₂ consumption at an air temperature of 25° C exceeding that between 34 and 35°C by 40%. In a minority of hatchlings this response was not seen. It was suggested that endothermy may develop at some time during the 24 h after hatching.Abbreviations bm body mass - C _total total thermal conductance of tissues and plumage - f respiratory frequency - FE_{O 2} fractional concentration of oxygen in air leaving chamber - FI_{O 2} fractional concentration of oxygen in air entering chamber - T _a an temperature - T _b deep-body temperature - V air-flow rate - VO₂ oxygen consumption     

Ethylene Production and Respiratory Behavior of the rin Tomato Mutant

Little or no change in ethylene or CO₂ production occurred in rin tomato mutant fruits monitored for up to 120 days after harvest. Of the abnormally ripening tomatoes investigated, including “Never ripe” (Nr Y a h, Nr c l₂ r), “Evergreen” (gf r) and “Green Flesh” (gf), only rin did not show a typical climacteric and ethylene rise.     

Effects of Slow Deep Breathing at High Altitude on Oxygen Saturation,Pulmonary and Systemic Hemodynamics

Slow deep breathing improves blood oxygenation (Sp_O2) and affects hemodynamics in hypoxic patients. We investigated the ventilatory and hemodynamic effects of slow deep breathing in normal subjects at high altitude. We collected data in healthy lowlanders staying either at 4559 m for 2–3 days (Study A; N = 39) or at 5400 m for 12–16 days (Study B; N = 28). Study variables, including Sp_O2 and systemic and pulmonary arterial pressure, were assessed before, during and after 15 minutes of breathing at 6 breaths/min. At the end of slow breathing, an increase in Sp_O2 (Study A: from 80.2±7.7% to 89.5±8.2%; Study B: from 81.0±4.2% to 88.6±4.5; both p<0.001) and significant reductions in systemic and pulmonary arterial pressure occurred. This was associated with increased tidal volume and no changes in minute ventilation or pulmonary CO diffusion. Slow deep breathing improves ventilation efficiency for oxygen as shown by blood oxygenation increase, and it reduces systemic and pulmonary blood pressure at high altitude but does not change pulmonary gas diffusion.     

Vigorous Dynamics Underlie a Stable Population of the Endangered Snow Leopard Panthera uncia in Tost Mountains,South Gobi,Mongolia

Population monitoring programmes and estimation of vital rates are key to understanding the mechanisms of population growth, decline or stability, and are important for effective conservation action. We report, for the first time, the population trends and vital rates of the endangered snow leopard based on camera trapping over four years in the Tost Mountains, South Gobi, Mongolia. We used robust design multi-season mark-recapture analysis to estimate the trends in abundance, sex ratio, survival probability and the probability of temporary emigration and immigration for adult and young snow leopards. The snow leopard population remained constant over most of the study period, with no apparent growth (λ = 1.08+−0.25). Comparison of model results with the “known population” of radio-collared snow leopards suggested high accuracy in our estimates. Although seemingly stable, vigorous underlying dynamics were evident in this population, with the adult sex ratio shifting from being male-biased to female-biased (1.67 to 0.38 males per female) during the study. Adult survival probability was 0.82 (SE+−0.08) and that of young was 0.83 (SE+−0.15) and 0.77 (SE +−0.2) respectively, before and after the age of 2 years. Young snow leopards showed a high probability of temporary emigration and immigration (0.6, SE +−0.19 and 0.68, SE +−0.32 before and after the age of 2 years) though not the adults (0.02 SE+−0.07). While the current female-bias in the population and the number of cubs born each year seemingly render the study population safe, the vigorous dynamics suggests that the situation can change quickly. The reduction in the proportion of male snow leopards may be indicative of continuing anthropogenic pressures. Our work reiterates the importance of monitoring both the abundance and population dynamics of species for effective conservation.     

The Effect of Framing and Normative Messages in Building Support for Climate Policies

Deep cuts in greenhouse gas emissions are required to mitigate climate change. However, there is low willingness amongst the public to prioritise climate policies for reducing emissions. Here we show that the extent to which Australians are prepared to reduce their country''s CO₂ emissions is greater when the costs to future national income are framed as a “foregone-gain”—incomes rise in the future but not by as much as in the absence of emission cuts—rather than as a “loss”—incomes decrease relative to the baseline expected future levels (Studies 1 & 2). The provision of a normative message identifying Australia as one of the world''s largest CO₂ emitters did not increase the amount by which individuals were prepared to reduce emissions (Study 1), whereas a normative message revealing the emission policy preferences of other Australians did (Study 2). The results suggest that framing the costs of reducing emissions as a smaller increase in future income and communicating normative information about others'' emission policy preferences are effective methods for leveraging public support for emission cuts.