Integrated global assessment of the natural forest carbon potential

Forests are a substantial terrestrial carbon sink, but anthropogenic changes in land use and climate have considerably reduced the scale of this system1. Remote-sensing estimates to quantify carbon losses from global forests2-5 are characterized by considerable uncertainty and we lack a comprehensive ground-sourced evaluation to benchmark these estimates. Here we combine several ground-sourced6 and satellite-derived approaches2,7,8 to evaluate the scale of the global forest carbon potential outside agricultural and urban lands. Despite regional variation, the predictions demonstrated remarkable consistency at a global scale, with only a 12% difference between the ground-sourced and satellite-derived estimates. At present, global forest carbon storage is markedly under the natural potential, with a total deficit of 226 Gt (model range = 151-363 Gt) in areas with low human footprint. Most (61%, 139 Gt C) of this potential is in areas with existing forests, in which ecosystem protection can allow forests to recover to maturity. The remaining 39% (87 Gt C) of potential lies in regions in which forests have been removed or fragmented. Although forests cannot be a substitute for emissions reductions, our results support the idea2,3,9 that the conservation, restoration and sustainable management of diverse forests offer valuable contributions to meeting global climate and biodiversity targets.

The global biogeography of tree leaf form and habit

Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17-34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cycling.

Native diversity buffers against severity of non-native tree invasions

Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species1,2. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies3,4. Here, leveraging global tree databases5-7, we explore how the phylogenetic and functional diversity of native tree communities, human pressure and the environment influence the establishment of non-native tree species and the subsequent invasion severity. We find that anthropogenic factors are key to predicting whether a location is invaded, but that invasion severity is underpinned by native diversity, with higher diversity predicting lower invasion severity. Temperature and precipitation emerge as strong predictors of invasion strategy, with non-native species invading successfully when they are similar to the native community in cold or dry extremes. Yet, despite the influence of these ecological forces in determining invasion strategy, we find evidence that these patterns can be obscured by human activity, with lower ecological signal in areas with higher proximity to shipping ports. Our global perspective of non-native tree invasion highlights that human drivers influence non-native tree presence, and that native phylogenetic and functional diversity have a critical role in the establishment and spread of subsequent invasions.

Co-limitation towards lower latitudes shapes global forest diversity gradients

The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers.

Modelling potentially suitable lac cultivation zones of Butea monosperma to promote livelihood security in rural India

The present paper highlights the importance of lac cultivation through Butea monosperma. We have modelled the suitable habitat of major lac host B. monosperma using MAXENT for the current and future climatic scenarios (RCPs 2.6, 4.5, 6.0 and 8.5). The study suggested the dominance of suitable habitats of B. monosperma in central-eastern to eastern and southern parts of the country. Temperature seasonality (Bio_4) was the most significant bioclimatic variable in regulating the distribution of B. monosperma followed by elevation and annual precipitation (Bio_13). The projection for the year 2050 suggested the habitat shift towards the eastern and southern parts. The study indicated the major habitat of B. monosperma continued to exist in the Chotanagpur plateau in eastern India. The model predicted approximately a 9–13% decrease in the overall potential habitat of B. monosperma by 2050, and the distribution of species would be nearly extinct from the northern and western parts. Presently, only the 5% lac host trees are being utilised for lac cultivation, and the study suggested that conservation and promotion of B. monosperma on projected suitable habitats and even by utilising 25% of resources, the lac production may jump manifold catering to global demand, rural economy and employment and shall contribute towards ‘Self Reliant India’.

The dark cloud with a silver lining: Assessing the impact of the SARS COVID-19 pandemic on the global environment

The Severe Acute Respiratory Syndrome-Coronavirus Disease 2019 (COVID-19) pandemic caused by a novel coronavirus known as SARS-CoV-2 has caused tremendous suffering and huge economic losses. We hypothesized that extreme measures of partial-to-total shutdown might have influenced the quality of the global environment because of decreased emissions of atmospheric pollutants. We tested this hypothesis using satellite imagery, climatic datasets (temperature, and absolute humidity), and COVID-19 cases available in the public domain. While the majority of the cases were recorded from Western countries, where mortality rates were strongly positively correlated with age, the number of cases in tropical regions was relatively lower than European and North American regions, possibly attributed to faster human-to-human transmission. There was a substantial reduction in the level of nitrogen dioxide (NO₂: 0.00002 mol m^-2), a low reduction in CO (<0.03 mol m^-2), and a low-to-moderate reduction in Aerosol Optical Depth (AOD: ~0.1-0.2) in the major hotspots of COVID-19 outbreak during February-March 2020, which may be attributed to the mass lockdowns. Our study projects an increasing coverage of high COVID-19 hazard at absolute humidity levels ranging from 4 to 9 g m^-3 across a large part of the globe during April-July 2020 due to a high prospective meteorological suitability for COVID-19 spread. Our findings suggest that there is ample scope for restoring the global environment from the ill-effects of anthropogenic activities through temporary shutdown measures.

Wrinkled titanium nitride nanocomposite for robust bendable electrodes

Electrical contacts and interconnections are critical components for all electronic devices. Bendable electrodes with enhanced electro-mechanical properties are highly desirable to develop innovative wearable electronic devices. Herein we report on a fabrication method for robust bendable coatings based on titanium nitride (TiN) thin films and silver nanowires (Ag NWs). TiN and TiN-AgNWs nanocomposites were deposited on polyethylene terephthalate (PET) substrates using a plasma enhanced pulsed laser deposition (PLD) technique. The resulting TiN coatings exhibit excellent adhesion to PET and their sheet resistance can be tuned using a dual frequency PLD process and further decreased by incorporating Ag NWs into the TiN layers. Sample sheet resistance was decreased down to values as low as [Formula: see text] corresponding to the formation of TiN-AgNWs nanocomposites. The electro-mechanical robustness of TiN based coatings were evaluated by four-probe resistance measurements in situ under cyclic bending tests. We show that the TiNAgNWs nanocomposites surpass both ITO and Ag NWs coatings in terms of mechanical robustness and electrical conductivity respectively. These nanocomposites withstand high strain fatigue loading up to ϵ = 2.6%, keeping R _S below 5 Ω/□. The data demonstrates that the incorporation of Ag NWs in TiN coatings improve the mechanical robustness, limiting the crack growth and propagation, with low optical transmittance decrease (≈11%). These results indicate that Ag NWs based nanocomposites are attractive materials for flexible electronic devices.

Intubation in the Intensive Care Unit: C-MAC video laryngoscope versus Macintosh laryngoscope

PURPOSE

Various modifications of the Macintosh blade and direct laryngoscopy have been incorporated into practice to improve the intubation success rate and avoid complications while ensuring patient safety. This study evaluates the usefulness of two different direct laryngoscopy methods used by operators with various level of experience in the Intensive Care Unit.

MATERIAL AND METHODS

In a single centre prospective study, C-MAC and Macintosh laryngoscopes were compared in terms of laryngoscopy and intubation outcomes such as glottic visualization, number of intubation attempts, intubation success and satisfaction score.

RESULTS

During the one-year study period, 263 patients were evaluated and data of 218 patients were analyzed. The rate of successful first attempt intubation was higher in the video laryngoscope group (VL) (84% vs 57%; P<0.001). A significantly greater number of patients in the Macintosh laryngoscopy group had difficult visualization of the glottis in terms of the modified Cormack and Lehane classification and Percentage of Glottic Opening scale.

CONCLUSION

The use of video laryngoscope for intubation in ICU settings results in better visualization of the glottis and a higher incidence of successful intubation attempts.

The analgesic and acute anti-inflammatory effect of the ethanolic extract of the leaves of Paederia foetida (EEPF) on experimental animal models

Objective:To study the analgesic and acute anti-inflammatory effect of the ethanolic extract of the leaves of Paederia foetida (EEPF) on experimental animal models. Materials and Methods: Fresh leaves were collected, air-dried, powdered, and percolated in 95% ethanol. Acute toxicity test was done according to OECD guidelines. Healthy albino rats (150-200 gm) of either sex were taken and divided into five groups with six animals in each group for central analgesic activity by tail flick method. Peripheral analgesic activity by 1% glacial acetic acid induced writhing test by taking albino mice (20-30 gm) of either sex which were divided into three groups with six animals in each. EEPF was used in a dose of 500 mg/kg bodyweight subcutaneously for tail-flick method and orally for writhing test. In tail-flick method the basal reaction time was taken and a cut-off period of 10 sec was observed. Reaction time were recorded at predrug, 15, 30, 60, 90, 120, 150 and 180 minutes after administration of drug . The standard drug used for central analgesic activity was pethidine 5 mg/kg bw, naloxone 1mg/kg as antagonist and naloxone 1mg/kg bw with 500mg/kg bw of EEPF to study the central mechanism of action. The standard drug used for peripheral analgesic activity was aspirin 100mg/kg bw orally. A control group was maintained in all the models. For anti-inflammatory study, three groups of animals of either sex (n = 6), weighing 150-200g of the species Rattus norvegicus were taken for the study. Group A was taken as control (Normal salie, 10 mL/kg body weight), Group B as test group (EEPF 500 mg/kg body weight), and Group C as standard (Aspirin 100 mg/kg body weight). The animals were studied for acute inflammation by Carrageenan-induced rat paw edema. Statistical analysis  was done by one-way analysis of variance followed by multiple comparison tests.Results: EEPF significantly increased the reaction time in tail-flick method (p<0.05) whereas the combination of naloxone and EEPF decreased the reaction time indicating that naloxone inhibits the analgesic effect of EEPF. In 1% glacial acetic acid induced writhing EEPF reduced writhing significantly In acute inflammation, there was significant inhibition of paw edema in Groups B, C in comparison with Group A (P < 0.05). Conclusion:The ethanolic extract of Paederia foetida has significant analgesic and anti-inflammatory activity. DOI: http://dx.doi.org/10.3329/bjms.v11i3.11723 Bangladesh Journal of Medical Science Vol. 11 No. 03 July’12

Efficacy of Heatsynch protocol for induction of estrus, synchronization of ovulation and timed artificial insemination in yaks (Poephagus grunniens L.)

The objective of this study was to test the efficacy of induction of estrus, synchronization of ovulation and timed artificial insemination in anestrous yaks using the Heatsynch protocol. In Experiment 1, 10 anestrous yaks were administered an analogue of gonadotropin releasing hormone (GnRH) followed by prostaglandin (PG)F2alpha 7 days later and then estradiol cyponate (ECP) 24 h after that. Ovulation was detected by rectal palpation at 2h intervals beginning at the initial signs of estrus. Blood samples were collected at 2h intervals beginning at the time of ECP injection up to 2h after the occurrence of ovulation for the determination of LH and progesterone. All the animals responded to the Heatsynch protocol with expression of estrus and synchronization of ovulation. The mean time interval from the ECP injection to ovulation was 59.4+/-2.62 h (range 50-72 h). The interval from the LH peak to ovulation was 30.2+/-2.3 h. The high degree of synchrony in ovulation could be attributed to the synchrony in the timing of LH peaks. In Experiment 2, 10 anestrous yaks were treated with the Heatsynch protocol (as in Experiment 1) and TAI was performed at 48 and 60 h after the ECP treatment. Concurrently, 16 cycling yaks were inseminated approximately 12 h after detection of spontaneous estrus. Pregnancy rates were similar in both groups, 40% for TAI and 43.75% for yaks inseminated following spontaneous estrus (p>0.05). From this study, two conclusions can be drawn. First, the Heatsynch protocol can be successfully used to induce and synchronize estrus in anestrous yaks and, second, ovulation following the Heatsynch protocol is synchronized adequately to permit the use of fixed time AI in this species.

Coinfection of Japanese encephalitis with neurocysticercosis: an imaging study

BACKGROUND AND PURPOSE

Coinfection of neurocysticercosis (NCC) and Japanese encephalitis (JE) has been advocated as more than a chance occurrence resulting in poor outcome. We undertook this study to determine whether the association of the 2 infections is more than a chance occurrence, to define the imaging characteristics of coinfections, and to explore the synergistic effect of NCC in JE.

MATERIALS AND METHODS

Sixty-two patients with JE were studied by MR imaging and CT. CT was done in 53 and MR imaging in 53 patients. The diagnosis of JE was established by CSF JE virus immunoglobulin M capture (MAC) enzyme-linked immunosorbent assay (ELISA). NCC was diagnosed from imaging. A control group of 385 patients was evaluated by imaging for prevalence of NCC in the general population.

RESULTS

A significantly high association of NCC with JE (19.3%) was observed in comparison with prevalence of NCC in control subjects (1.04%; P = .0003). JE lesions in coinfection were significantly asymmetric with lateralization to the side of the brain having the maximum NCC or a cyst with edema. The JE lesions in coinfections were more florid, with a significantly higher proportion of abnormal CT scans and more abnormal MR imaging. Coinfections were significantly more common in children. Significantly lower CSF MAC-ELISA units in patients with coinfection reflected low CSF IgM levels, suggesting altered immune status.

CONCLUSION

In our series, there was a strong association between JE and NCC, and, thus, this coinfection was more than a chance occurrence.

Temporal lobe involvement in Japanese encephalitis: problems in differential diagnosis

BACKGROUND AND PURPOSE

On MR imaging and CT, Japanese encephalitis (JE) shows lesions in the thalami, substantia nigra, basal ganglia, cerebral cortex, cerebellum, brain stem, and white matter, whereas temporal lobe involvement is characteristically seen in Herpes simplex encephalitis (HSE). Temporal lobe involvement in JE may cause problems in differentiating it from HSE. We undertook this study to show the temporal lobe involvement pattern in JE and highlight differentiating features from temporal lobe involvement in HSE.

METHODS

Sixty-two patients with JE underwent CT or MR imaging or both. MR imaging was done in 53 and CT in 53. The diagnosis of JE was confirmed by cerebrospinal fluid (CSF) IgM enzyme-linked immunosorbent assay.

RESULTS

Eleven (17.7%) patients showed temporal lobe involvement with abnormal MR imaging in all. All the patients showed hippocampal involvement. Two patients showed extension of lesions into the amygdala and uncus with insular involvement in 1. The rest of the temporal lobe was spared. All patients had thalamic and substantia nigra involvement with basal ganglia involvement in 7. Six of 9 CT scans were abnormal and the temporal lesions were seen in 2.

CONCLUSIONS

The temporal lobe involvement pattern is fairly characteristic and mostly involves the hippocampus, usually sparing the rest of the temporal lobe. This and the concurrent involvement of the thalami, substantia nigra (SN), and basal ganglia allow differentiation from HSE. However, if the temporal lobe involvement is more severe, laboratory tests may be the only way to differentiate it from HSE, and it may be prudent to start antiviral therapy in the interim period.

Macular function and morphology after peeling of idiopathic epiretinal membrane with and without the assistance of indocyanine green

AIM

To investigate macular function and morphology after surgical removal of idiopathic epiretinal membrane (IEM) with and without assistance of indocyanine green (ICG).

METHODS

A retrospective study as a consecutive case series, of 39 patients with IEM. 39 patients, 23 female, 16 male, mean age 67 years, underwent standard three port pars plana vitrectomy with removal of epiretinal membrane. Two groups of patients were consecutively operated: in 20 patients ICG 0.1% in glucose 5% was used to stain the epiretinal membrane. 19 patients underwent the identical procedure but without use of ICG. Postoperative follow up was 1-92 months (mean 15.5 months). Functional outcome was assessed with subjective improvement, best corrected visual acuity (BCVA), Amsler grid test, 10 degrees and 30 degrees automated perimetry (Heidelberg visual field analyser) (HFA), and Goldmann kinetic perimetry. Macular morphology was assessed with stereoscopic biomicroscopy and optical coherence tomography (OCT). The main outcome measures were macular function as determined by BCVA, presence of visual field defects, and metamorphopsia as determined by Amsler grid test, macular morphology as determined by slit lamp biomicroscopy, and OCT.

RESULTS

BCVA improved in 28 patients, remained unchanged in eight patients, and decreased in three patients. Improvement of BCVA was statistically significant in both groups (p = 0.003). Mean BCVA in patients operated with ICG improved from 0.33 preoperatively to 0.53 postoperatively. Mean BCVA in patients operated without ICG improved from 0.32 preoperatively to 0.54 postoperatively. Reduction of macular oedema as measured by OCT was statistically significant in both groups (p<0.01). There was no statistically significant difference in postoperative BCVA, macular oedema as measured by OCT, postoperative Amsler grid test, and subjective improvement between the two groups. The incidence of residual or recurrent epiretinal membrane was greater in the group operated without ICG (p = 0.014). Visual field defects were detected in one patient operated with ICG and in three patients operated without ICG.

CONCLUSIONS

Removal of epiretinal tissue with or without assistance of ICG improved visual function and reduced macular oedema in most patients. Adverse effects clearly attributable to the use of ICG were not observed but further investigation is warranted.