Forest biomass plays a crucial role in the global carbon cycle as a significant contributor derived from both soil and trees. This study focuses on investigating tree carbon stock (TCS) and ...estimating aboveground biomass (AGB) based on elevation within the Srivilliputhur Wildlife Sanctuary forest, while also exploring the various factors that influence their contribution. Utilizing a non-destructive approach for carbon estimation, we found that the total tree biomass in this region ranged from 220.9 Mg/ha (in Z6) to 720.6 Mg/ha (Z2), while tree carbon stock ranged from 103.8 to 338.7 Mg/ha. While Kruskal–Wallis tests did not reveal a significant relationship (
p
= 0.09) between TCS and elevation, linear regression showed a weak correlation (
R
2
= 0.002,
p
< 0.05) with elevation. To delve deeper into the factors influencing TCS and biomass distribution, we employed a random forest (RF) machine learning algorithm, demonstrating that stand structural attributes, such as basal area (BA), diameter at breast height (DBH), and density, held a more prominent role than climatic variables, including temperature, precipitation, and slope. Generalized linear models (GLM) were also utilized, confirming that BA, mean DBH, and elevation significantly influenced AGB (
p
≤ 0.001), with species richness, precipitation, and temperature having lower significance (
p
≤ 0.01) comparatively. Overall, the RF model exhibited superior performance (
R
2
= 0.92, RMSE = 0.12) in terms of root mean square error (RMSE) compared to GLM (
R
2
= 0.88, RMSE = 0.35). These findings shed light on the intricate dynamics of biomass distribution and the importance of both stand structural and climatic factors in shaping forest ecosystems.
Global biodiversity has already been altered by the climatic changes in various means like species migration, changes in habitat distribution, seasonality changes in phenology etc. In order to ...implement sustainable conservation or adaptation strategy, it is necessary to understand the impacts of climate change on both ecosystem and species level. Here we present an assessment on current and future habitat suitability distribution of Myristica dactyloides Gaertn. (MD), a medicinally and ecologically important tree species by using a maximum entropy (MaxEnt) species distribution model. The future predictions were done for the year 2050 and 2070 using the bioclimatic variables having 1km spatial resolution from two different models of fifth phase of the coupled model intercomparison project (CMIP5). This study was carried out in the Kolli hill, Eastern Ghats of India. The AUC values confirmed the accuracy of model prediction based on 22 occurrence points. Environmental variables’ contributions were evaluated using jackknife test. The more influencing variables will be annual temperature, annual precipitation and precipitation of wettest month. Finally, this study found that there will be a significant reduction in the habitat suitability distribution of Myristica dactyloides in the year 2050 and 2070 in the study area. Hence with the performance of the model, this study found that MaxEnt could be an effective tool for species rehabilitation and biodiversity conservation planning in the light of climate change.
A newly designed DC-AC three phase bidirectional converter (DATBC) with an encapsulated DC-DC converter (EDC) for the energy storage system (ESD) is analysed and investigated in this research paper. ...By using encapsulated or embedded or hidden DC-DC converter a stable and constant DC bus is developed between the encapsulated DC-DC converter and DC-AC three phase bidirectional converter. The proposed converter is entirely different from the traditional dual-stage DC-AC converter, because it takes less than 20% of power used for the DC-AC conversion process. So, this reduced power consumption increases efficiency to a considerable value. A new control technique for zero sequence has been adopted components are inserted in the modulating signal based on carrier pulse width modulation (CPWM). Working principle, implementation and characteristics of the DC-AC three phase bidirectional converter are analysed. Effectiveness and feasibility of the developed converter are examined with a proto-type model.
•Six fire frequency classes were obtained in the study area, between 1999 and 2013.•Fire return interval is increased to 9.28years from 3.3year (1989–2002).•Tree diversity decreased with increasing ...fire frequencies.•Low fire frequencies promote seedling density.•Stem size between 1 and 20cm dbh showed much variation across the fire classes.
This study was aimed to understand the effect of repeated fire on tropical dry deciduous forest in Mudumalai Tiger Reserve (MTR), Western Ghats. Tropical dry deciduous forests are prone to forest fire owing to high fuel load and long dry season. Fire frequency map of the study area was prepared for 15years from 1999 to 2013 using annual burn maps. Study area was stratified as B1 to B6 (one to six times burned) and compared to control (B0 – unburned during 1999–2013). Three plots were randomly laid in each stratum and seedlings; saplings and trees present in each plot were recorded. Species diversity indices showed increase in dominance and decrease in diversity with increasing fire frequency. Results showed that overall stem density (>1cm DBH) ranged from 576 (SD 112.69) (B1) to 236 (SD 20) individual ha−1 (B6). The basal area ranged from 36.8 (SD 2.19) m2ha−1 (B0) to 12.12 (SD 2.69) m2ha−1 (B5). Fire promoted seedling density from B0 to B2 and after that it started decreasing whereas sapling density was poor in all classes and recorded least in B6. Stem density of trees did not vary much up to B3 and started decreasing after that. Number of species decreased linearly with increasing fire frequency. In the analysis of dominant species, Tectona grandis showed a very significant mean difference in seedling, sapling and tree population whereas Terminalia cranulata did not show significant difference in mean densities of seedling, sapling or trees. It is found that fire with long interval can promote seedlings density but species diversity decreases with increasing fire frequency.
Successful adaptation to the environment requires an accurate response to external threats by recalling specific memories. Memory formation and recall require engram cell activity and synaptic ...strengthening among activated neuronal ensembles. However, elucidation of the underlying neural substrates of associative fear memory has remained limited without a direct interrogation of extinction-induced changes of specific synapses that encode a specific auditory fear memory. Using dual-eGRASP (enhanced green fluorescent protein reconstitution across synaptic partners), we found that synapses among activated neuronal ensembles or activated synaptic ensembles showed a significantly larger spine morphology at auditory cortex (AC)-to-lateral amygdala (LA) projections after auditory fear conditioning in mice. Fear extinction reversed these enhanced synaptic ensemble spines, whereas re-conditioning with the same tone and shock restored the spine size of the synaptic ensemble. We suggest that synaptic ensembles encode and represent different fear memory states.
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•Fear conditioning enhances spine morphology of activated synaptic ensemble in AC-LA•Fear extinction reduces fear-conditioning-induced enhancement of activated spines•Re-conditioning restores fear-extinction-induced reduction of activated spines•Spine morphology of activated synaptic ensembles correlates with fear memory state
Choi et al. show spine morphology dynamics of the AC-LA circuit during fear conditioning, extinction, and re-conditioning. Using input-specific and activity-dependent spine labeling, they demonstrate that activated spines are enhanced by fear conditioning and subsequently decreased by extinction, which is restored by re-conditioning.
•Low overpotential detection.•Obtained lower detection limits.•Good recovery rates.
A simple, biocompatible and an enzyme-free sensing platform was developed for detection of paraoxon. The surface of ...a glassy carbon electrode was modified with an electrodeposition of stearic acid/nanosilver composite at −0.7 V for 40 s. The paraoxon undergoes electro-reduction at −550 mV on the modified electrode, and the limits of detection (LOD) was calculated as 0.1 nM (S/N = 3) using differential pulse voltammetry which is lower than that of the existing materials reported. The high stability observed with the modified electrode for prolonging period indicated that the sensitivity of the electrode remains active for several runs of the analysis. The developed analytical strategy was implemented for onion and paddy grain samples and good recovery rates were observed. Also, it was applied for analyzing the purity of the commercial paraoxon sample. The reliability of the developed strategy was confirmed by comparing the results of electrochemical approach with that of HPLC technique.
This framework attempts to introduce a new Distributed denial-of-service (DDoS) attack detection and mitigation model. It is comprised of two stages, namely DDoS attack detection and mitigation. The ...first stage consists of three important phases like feature extraction, optimal feature selection, and classification. In order to optimally select the features of obtained feature sets, a new improved algorithm is implanted named Improved Update oriented Rider Optimization Algorithm (IU-ROA), which is the modification of the Rider Optimization Algorithm (ROA) algorithm. The optimal features are subjected to classification using the Deep Convolutional Neural Network (CNN) model, in which the presence of network attacks can be detected. The second stage is the mitigation of the attacker node. For this, a bait detection mechanism is launched, which provides the effective mitigation of malicious nodes having Distributed Denial-of-Service (DDoS) attacks. The experimentation is done on the KDD cup 99 dataset and the experimental analysis proves that the proposed model generates a better result which is 90.06% in mitigation analysis and the overall performance analysis of the proposed model on DDoS Attack Detection is 96% better than conventional methods.
In this article a low profile asymmetrical slotted Ultra-Wide Band (UWB) antenna is proposed for Wireless Body Area Networks (WBANs) applications. The antenna was fabricated using Printed Circuit ...Boards (PCBs). An improved radiation pattern was obtained with an optimized patch shape of the antenna that broadens the bandwidth and lowers the antenna’s profile. The proposed antenna is simulated in HFSS and CST Simulator, and the proposed antenna is fabricated on FR4 substrate with the reduced ground plane. In frequency ranges from 2.50 to 10.97 GHz simulation as well as measured results show that the reflection coefficient (
S
11
) of the antenna is below − 10 dB and increased impedance bandwidth of 126%. The proposed antenna has desired radiation pattern and gain for wearable application. The wearable performance of proposed antenna on chest, leg, and the arms of the human body is analyzed with Specific Absorption Rate (SAR). The maximum value of the SAR is 0.785 W/Kg which is less than threshold value of 1.6 W/kg. The time-domain behavior of proposed antenna is investigated with the time domain parameters such as Group delay, Fidelity factor and Mean realized gain. The time domain results are evident for the proposed antenna is capable of pulse signal transmission and reception.
Ursolic acid (UA), a pentacyclic triterpenoid carboxylic acid, is the major component of many plants including apples, basil, cranberries, peppermint, rosemary, oregano and prunes and has been ...reported to possess antioxidant and anti-tumor properties. These properties of UA have been attributed to its ability to suppress NF-κB (nuclear factor kappa B) activation. Since NF-κB, in co-ordination with NF-AT (nuclear factor of activated T cells) and AP-1(activator protein-1), is known to regulate inflammatory genes, we hypothesized that UA might exhibit potent anti-inflammatory effects.
The anti-inflammatory effects of UA were assessed in activated T cells, B cells and macrophages. Effects of UA on ERK, JNK, NF-κB, AP-1 and NF-AT were studied to elucidate its mechanism of action. In vivo efficacy of UA was studied using mouse model of graft-versus-host disease. UA inhibited activation, proliferation and cytokine secretion in T cells, B cells and macrophages. UA inhibited mitogen-induced up-regulation of activation markers and co-stimulatory molecules in T and B cells. It inhibited mitogen-induced phosphorylation of ERK and JNK and suppressed the activation of immunoregulatory transcription factors NF-κB, NF-AT and AP-1 in lymphocytes. Treatment of cells with UA prior to allogenic transplantation significantly delayed induction of acute graft-versus-host disease in mice and also significantly reduced the serum levels of pro-inflammatory cytokines IL-6 and IFN-γ. UA treatment inhibited T cell activation even when added post-mitogenic stimulation demonstrating its therapeutic utility as an anti-inflammatory agent.
The present study describes the detailed mechanism of anti-inflammatory activity of UA. Further, UA may find application in the treatment of inflammatory disorders.
•Nanocrystalline Te-rich Bi2Te3 thin film is prepared by e−−beam deposition at 300 K.•Vacuum annealing lead to intergrown Te-rich layers between the quintuples.•Disordered planar structures are ...mostly concentrated on the crystallite surface.•Seebeck coefficient becomes maximum (~ 97 μV/K) for the film annealed at 200 °C.•Te-rich Bi2Te3 with S2σ ~29 × 10−4 W/K2m is good for thermoelectric applications.
Tellurium-rich Bi2Te3 thin films are deposited by electron−beam evaporation technique at 300 K. These as-deposited thin films are further annealed at 100 °C, 200 °C and 300 °C for 1 h at a pressure of 3 × 10−4 Pa. X-ray diffraction (XRD) patterns of as-deposited films distinctly show Te phase along with Bi2Te3. Peak intensity ratio suggests the polycrystalline nature of as-deposited Bi2Te3 films. On vacuum annealing Te-rich Bi2Te3 films exhibit improved crystallinity with a c-axis preferred orientation. In addition, structural features related to Te and Bi2Te3 composition change with Te fraction diminishing on annealing at 300 °C. From Raman spectral studies, the presence of distinct Te-rich regions, predominantly within the interlayers of Bi2Te3, are discerned. Te becomes structurally integrated within the quintuples of Bi2Te3 lattice as intergrown layers. Disordered planar structures, mostly concentrated on crystallite surfaces result from Te accumulations as evidenced in high-resolution transmission electron microscopy lattice images and energy dispersive X-ray spectroscopy mapping. These are consistent with the observations from XRD and Raman studies further confirming Te-rich Bi2Te3 characteristics. Electrical properties of Te-rich Bi2Te3 thin films exhibit n-type semiconductor behaviour. Seebeck coefficient for as-deposited film is ~ 32 μV/K, which increases to ~ 97 μV/K on 200 °C annealing. Resistivity increases from 1.39 × 10−4 Ωcm to 18.76 × 10−4 Ωcm and power factor changes from 7.4×10−4W/K2m to 27.17×10−4W/K2m going through a maximum at 200 °C upon systematic annealing. Te-rich Bi2Te3 thin films annealed at 200 °C exhibit high power factor (∼29×10−4W/K2m) for a wide range of temperature gradients ( ΔT from 30 °C to 165 °C).
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