Low Index Values Research Articles

Organic Matter and Generation Potential of Paleozoic Deposits in the Tal’bei Block of the Chernyshev Ridge (Timan–Pechora Petroleum Province)

Abstract—The study area is located within the Chernyshev Ridge, a fold–thrust structure, which is a promising area for oil and gas exploration in the Timan–Pechora province. Petroleum source rocks of Paleozoic (from Upper Ordovician to lower Carboniferous) deposits stripped by the Vorgamusyurskaya-1 well in the Tal’bei block of the Chernyshev Ridge were studied by lithological, petrographic, organic-petrology, and organic-geochemistry methods. Most of the section is characterized by low values of Corg (<0.5%), genetic potential (S1 + S2 < 0.5 mg HC/g rock), and hydrogen index (HI < 100 mg HC/g Corg). Petroleum source rocks with elevated values of Corg (up to 0.9%), S1 + S2 (up to 2.1 mg HC/g rock), and HI (up to 277 mg HC/g Corg) were identified at different stratigraphic levels of the section: Upper Devonian (D3tm–sr), upper Silurian (S2gj), and Upper Ordovician (O3mt). The maceral composition of organic matter (OM) and the distribution of hydrocarbons in the saturated fraction of bitumens indicate that petroleum source rocks include only marine OM (type II kerogen). The degree of catagenesis of OM was estimated based on the bituminite reflectance (RVeq), Rock-Eval pyrolysis (Tmax), and conodont color alteration index (CAI). The available RVeq (0.63–0.84%), Tmax (430–443 °C), and CAI (1.5–2.0) data indicate that the entire Paleozoic well section is in the oil window (MC1–MC3). The new data refined the catagenetic zoning of the sedimentary section, according to which the OM reached the following gradations: MC1 in the lower Carboniferous and Famennian deposits, MC2 in the interval from the Frasnian to the upper part of the lower Silurian, and MC3 in the lower part of the lower Silurian and in the Upper Ordovician. The results of the study of petroleum source rocks and the type and maturity of OM will be the basis for basin modeling, which will increase the reliability of reconstructions of oil and gas formation at the Chernyshev Ridge.

Use of Moringa oleifera leaves (sole or combined with concentrate) in rabbit feeding: Effects on performance, carcass characteristics and meat quality attributes

Sixty Chinchilla rabbits (28 days old) were divided into three equal groups (n = 20). Rabbits in MOL0 (control) were fed pellets containing 700 g cowpea hay/kg pellet as forage source, whereas rabbits in MOL700 and MOL950 were fed pellets containing 700 and 950 g moringa leaves/kg feed pellets, respectively. Average daily gain and feed conversion ratio was comparable in MOL700 and MOL0, however, it was higher in MOL950. Among the carcass traits, dressing percent was higher while, chilling loss was lower in MOL700 treatment. The Longissimus thoracis muscle of rabbits fed moringa leaves containing pellets (MOL700 and MOL950) had lower saturated fatty acid content, higher C18:3n-3 and total n-3 fatty acids along with lower thrombogenic index value. Hence, incorporating moringa leaves at 70% level is beneficial in terms of improved growth performance and functional attributes of meat than diet- containing sole moringa leaves.

Genetic diversity and population structure of barley landraces from Southern Ethiopia's Gumer district: Utilization for breeding and conservation.

Barley is the fifth most important food crop in Ethiopia. The genetic relationship and population structure studies of barley are limited to gene bank collections. Therefore, this study fills a gap by investigating the selection, consumption, economic value, genetic diversity, and population structure of farm-collected barley from the Gumer district of the Gurage Zone, which has received little attention. The information on the use of barley in the study area was collected using semi-structured interviews and questionnaires. 124 households of 11 kebeles, the smallest community unit, were interviewed. Barley landraces collected were compared with those collected from Japan, the United States (USA), and other Ethiopian locations. Illumina iSelect (50K genotyping platform) was used to identify single nucleotide polymorphisms (SNP) (20,367). Thirty landraces were found in Gumer. Burdaenadenber had the highest on-farm Shannon index estimate (2.0), followed by Aselecha (1.97) and Enjefo (1.95). Aselecha and Fetazer had the highest (44%) and the lowest (29%) richness values, respectively. High and low Simpson index values were found in Aselecha (84%) and Wulbaragenateretero (79%), respectively. The neighbor-joining tree revealed that Gumer landraces formed a separate subcluster with a common ancestral node; a sister subcluster contained barley landraces from Japan. According to the population structure analysis, barley landraces from Gumer differed from Japan and the United States. The principal component analysis revealed that US barley was the most distant group from Gumer barley. The markers' allele frequencies ranged from 0.10 to 0.50, with an average value of 0.28. The mean values of Nei's gene diversity (0.38) and the polymorphic information content (0.30) indicated the presence of high genetic diversity in the samples. The clustering of accessions was not based on geographic origin. Significant genetic diversity calls for additional research and analysis of local barley diversity because the selection and use of barley in Ethiopia would have been affected by the preference of ethnic groups.

Heavy metal pollution in surface sediments and human health assessment in southern Al-Khobar coast, Saudi Arabia

Surface sediment samples from twenty-nine stations in south Al-Khobar coastline, Arabian Gulf, have been examined to assess the heavy metal contamination and impact on human health through dermal contact. The content in Cu, Zn, Cd, Pb, Fe, Mn, Co, Hg and Ni, was evaluated. Pollution index, modified degree of contamination, and pollution load index agreed to exclude heavy metal pollution. Differently, soil pollution index and Nemerow integrated pollution index pointed out moderate and heavy pollution grade for Hg and Cu, respectively. The human health assessment, according to the low values of the hazard index ˂ 1.0 for both adults and children, excluded any significant impact on the human body. The chronic daily intake and the total lifetime cancer risk also were consistent in excluding any risk to human health. Similarly, the carcinogenic risks for Pb and Cd, and the total cancer risk ˂1 × 10−6, did not imply significant health hazards.

Acidic soil tolerance of sugarcane and <i>Erianthus</i> root assessed by cell membrane stability

Sugarcane (Saccharum spp.) growth and yield decrease in acidic soil (low pH and high Al content) conditions owing to impaired nutrient and water absorption. An efficient method to evaluate acid tolerance needs to be developed to utilize Erianthus arundinaceus to improve acid tolerance in sugarcane. Herein, we performed a root electrolyte leakage assay to quantitatively evaluate and compare the acid tolerance of the roots of sugarcane cultivar NiF8 and E. arundinaceus accession JW630 under various treatments of acid solutions in laboratory. Additionally, cellular damage of root was observed anatomically and their growth in acidic soil was verified by pot cultivation. To detect the interspecific difference in injury index of root by measuring electrolyte leakage, the following method was found suitable: initial washing for 15 min, acid stress treatment with 3% Al2(SO4)3 solution for 2 h, and leaking electrolyte from the damaged cells in ultrapure water for 2–4 h. The index was aligned with the relative growth rate (RGR) under acidic soil (pH 5.0), as E. arundinaceus with a lower index value exhibited a higher RGR. Callose, indicative of cellular damage, was deposited both after exposure to short-term and long-term acid stress in the exodermis of sugarcane, which showed higher injury index and lower RGR than those of E. arundinaceus, whereas callose deposition was not observed in E. arundinaceus even after acid stress treatments. Our results strongly suggest that the injury index measurements can be used to quantitatively evaluate differences in acid tolerance between sugarcane and Erianthus roots.

A Novel Composed Index to Evaluate the Right Ventricle Free-Wall Adaptation Against Ventricular Wall Stress in Acute Pulmonary Embolism.

Pulmonary embolism severity index and simplified pulmonary embolism severity index have been utilized in initial risk evaluation in patients with acute pulmonary embolism. However, these models do not include any imaging measure of right ventricle function. In this study, we proposed a novel index and aimed to evaluate the clinical impact. Our study population comprised retrospectively evaluated 502 patients with acute pulmonary embolism managed with different treatment modalities. Echocardiographic and computed tomographic pulmonary angiography evaluations were performed at admission to the emergency room within maximally 30 minutes. The formula of our index was as follows: (right ventricle diameter × systolic pulmonary arterial pressure-echo)/(right ventricle free-wall diameter × tricuspid annular plane systolic excursion). This index value showed significant correlations to clinical and hemodynamic severity measures. Only pulmonary embolism severity index, but not our index value, independently predicted in-hospital mortality. However, an index value higher than 17.8 predicted the long-term mortality with a sensitivity of 70% and specificity of 40% (areas under the curve = 0.652, 95% CI, 0.557-0.747, P =.001). According to the adjusted variable plot, the risk of long-term mortality increased until an index level of 30 but remained unchanged thereafter. The cumulative hazard curve also showed a higher mortality with high-index value versus low-index value. Our index composed from measures of computed tomographic pulmonary angiography and transthoracic echocardiography may provide important insights regarding the adaptation status of right ventricle against pressure/wall stress in acute pulmonary embolism, and a higher value seems to be associated with severity of the clinical and hemodynamic status and long-term mortality but not with in-hospital mortality. However, the pulmonary embolism severity index remained as the only independent predictor for in-hospital mortality.

Cost and Marketing Channels of Khmer Craftsmen's Brown Palm Sugar Production in Chau Lang, Vietnam

The current investigation was carried out both quantitative and qualitative methods in Chau Lang of the Tri Ton district where it is known that 65% of the village's families are Khmer. With the aid of in-person interviews using a pre-tested questionnaire, a semi-structured interview schedule, and an open discussion method, primary data were gathered for the study from 250 sampling observations from various stakeholders, including 105 farmers and 145 intermediaries in various channels. The findings showed that the average cost of production for one kilogram of palm sugar was 5,302 VND. There are three main channels in the marketing chain: Farmers, Middlemen, Wholesalers, Retailers, and Consumers in Channel 1, Farmers, Wholesalers, Retailers and Consumers in Channel 2, and Farmers, Retails, and Consumers in Channel 3. Channel 3 has the greatest marketing efficiency, at 19.52%, followed by Channels 2 and 1, at 18.36% and 15.76%, respectively. Additionally, Channels 1 and 2 have lower monopoly index values than Channel 3, suggesting trader dominance in the marketing of palm sugar products. It also demonstrates how little influence artisans have on the product price. An enterprise that aids artisans in selling palm sugar, Chau Lang village, must grow. In order to encourage the Khmer to continue working in the village as they have done for generations, it is important to find how to help these households and boost the income from palm sugar production. Keywords: Brown Palm Sugar, Production Cost, Marketing Channel, Craftsmen.

Phytoplankton-Zooplankton Community Structure in Coal Mining Subsidence Lake.

Land subsidence from coal mining has shaped new artificial aquatic ecosystems, these subsidence lakes are known for their restricted ecological system, water pollution, and extreme habitat conditions. However, knowledge concerning the community structure of plankton in these types of water bodies is still limited. Therefore, both phytoplankton and zooplankton communities' abundance, distribution, and diversity, as well as relations of these communities to physicochemical water quality variables were analyzed, alongside the interaction between phytoplankton and zooplankton groups. The results indicate zooplankton abundance was 842.375 to 186,355.0 ind./L. Biomass ranged from 0.3408 to 10.0842 mg/L. Phytoplankton abundance varied between 0.541 × 106 cell/L and 52.340 × 106 cell/L while phytoplankton wet biomass ranged from 0.5123 to 5.6532 mg/L. Pearson correlation analysis revealed that both the zooplankton and phytoplankton total densities were significantly correlated with nutrients (TN, TP, PO43-) and CODcr; zooplankton abundance was significantly correlated with phytoplankton abundance. According to the biodiversity index of Shannon-Wiener, both phytoplankton and zooplankton revealed less biodiversity in the subsidence water region than in the Huihe river system and Xiangshun canal, with values ranging from 0.20 to 2.60 for phytoplankton and 1.18 to 2.45 for zooplankton; however, the phytoplankton community showed lower biodiversity index values compared to the zooplankton community. Overall, the knowledge gleaned from the study of plankton community structure and diversity represents a valuable approach for the evaluation of the ecological conditions within the subsidence lakes, which has significant repercussions for the management and protection of aquatic environments in mining areas.

Diversity and Distribution of Phaeophyta Macroalgae in Pedalen Coastal Waters, Kebumen

Pedalen Beach, Kebumen, has a type of water substrate consists of sand, coral fragments, and coral overgrown with macroalgae. This study aims to determine the species diversity and distribution pattern of Phaeophyta found in that waters. This research is to explore and utilize macroalgae as a sustainable alginate resource. This study uses a survey method, employing the line transect method randomly. The research variables were species diversity and the distribution pattern of Phaeophyta. The main parameters were the number of species and individuals of each species. Supporting parameters include current velocity, nitrate content, brightness, depth, tide, salinity, temperature, and pH. The data were analyzed using the Shannon-Wiener diversity index (H’) to determine the level of species diversity and the Morisita distribution index (Id) to describe the distribution pattern of macroalgae species. We found five Phaeophyta species consisting of Padina australis, Dictyota dichotoma, Turbinaria ornata, Sargassum crassifolium, and S. polycystum. The diversity of Phaeophyta is classified as low diversity index value (H’) with distribution patterns of uniform macroalgae species. The results of the measurement of physical and chemical factors of the waters showed that the condition of the Pedalen Beach waters was quite good for the growth of Phaeophyta.
 
 Keywords: alginate, macroalgae species, Phaeophyta, water substrate

Drying of non-chemically prepared nanofibrillated cellulose from lime residue: Effects of drying methods on fiber morphology, physicochemical properties and redispersibility

The effects of drying methods, i.e., hot air oven and spray drying, defibrillation step and use of maltodextrin as a drying aid on microstructure as well as water redispersibility of dried nanofibrillated cellulose (NFC) were investigated; NFC-to-maltodextrin ratios were varied at 1:0, 1:1, 1:1.5 or 1:2. Spray-dried NFCs possessed lower crystallinity index (CI) values than oven-dried NFC. Higher added maltodextrin content resulted in lowered CI values due to an increase in the amorphous fraction within the samples. Freshly prepared NFC suspension exhibited gel-like behavior, while suspensions prepared by redispersing any dried NFC in water lost such a behavior. High pressure (100 MPa) applied during microfluidization defibrillation is postulated to cause the degradation of pectin, leading to the loss of its capability to serve as Van der Walls interactions and hydrogen bonding formation inhibitor. Although maltodextrin could somehow help form a dispersed fibrillar structure upon water reconstitution, the extents of such a structure in all cases were still not adequate to regain the gel-like behavior.

Prefrontally modulated vagal neuroimmunomodulation is associated with telomere length.

Accumulated senescent cells are proposed to be one of the main drivers of age-related pathology such as dementia and cancer through disruption of tissue structure and function. We recently proposed the Neuro-Immuno-Senescence Integrative Model (NISIM), which relates prefrontally modulated vagal tone and subsequent balance between vagal and sympathetic input to the spleen to inflammatory responses leading to generation of reactive oxygen species and oxidative telomere damage. In this study, we assess inflammation as a mediator in the relationship between prefrontally modulated vagal tone and leukocyte telomere length (LTL). We also assess the relationship between a recently proposed index of vagal neuroimmunomodulation (vagal tone/inflammation ratio; NIM index) and telomere length. This study uses participant data from a large nationally representative longitudinal study since 1974 with a total of 45,000 Norwegian residents so far. A sub-sample of 131 participants from which ultrashort recordings (30 s) of vagal tone, c reactive protein, and LTL could be obtained were included in the study. Relationships were analyzed with Pearson's correlations and hierarchical multiple linear regression using either vagal tone and CRP or the NIM index to predict telomere length. Vagal tone was a significant positive predictor of telomere length but this was not mediated by c reactive protein, even after controlling for confounders. The NIM index was a significant positive predictor of telomere length, also when controlling for confounders. In a follow-up analysis simultaneously comparing telomere length between groups with high and low values of vagal tone, and between groups with high and low NIM index values, telomere length was only significantly different between NIM index groups. This is the first study suggesting that prefrontally modulated vagal neuroimmunomodulation is associated with telomere length thus supporting the NISIM. Results indicate that the NIM index is a more sensitive indicator of vagal neuroimmunomodulation than vagal tone and CRP in isolation.

Digitalization Index: Case for Banking System

Economy digitalization has become a trend during the pandemic. The banking sector was also one of the first to face the need to accelerate digitalization. This work is devoted to developing a digitalization index for both the banking sector and an individual bank based on a set of indicators calculated according to data from the World Bank and data from commercial banks. At a macro level, the study concluded that the pandemic has accelerated the digitalization of the banking sector in all the monitored countries; however, a significant increase was observed in countries with lower index values in the pre-pandemic period. At the micro-level, the study showed that digital banks had benefited from digitalization more during the pandemic, unlike classical banks.

Clinical study of ganshuang granule combined with tenofovir in the treatment of chronic hepatitis B complicated with nonalcoholic fatty liver disease.

Objective: This study aims to investigate the clinical efficacy of Ganshuang granules combined with tenofovir, an antiviral drug, in the treatment of chronic hepatitis B complicated with nonalcoholic fatty liver disease. Methods: A total of 92 patients with chronic hepatitis B combined with non-alcoholic fatty liver who were treated in our Hospital from January 2020 to December 2021 were included as the research objects. According to the method of random number table, the patients were divided into the control group (n = 42) and the treatment group (n = 50). The control group was treated with silibinin meglumine tablets and tenofovir, while the treatment group was treated with Ganshuang granules combined with silybin meglumine tablets and tenofovir. Before and after treatment, liver function index, liver hardness measurement (LSM), controlled attenuation parameter (CAP), HBV-DNA serum load and body mass index (BMI) were observed. Results: Compared with the baseline, ALT, AST and GGT were significantly improved in both groups after treatment (p < 0.05), while TBIL indexes were not significantly different before and after treatment (p > 0.05). Patients in the treatment group had significantly lower ALT and AST index values than the control group at 12 and 24weeks of treatment (p < 0.05). At 12 and 24weeks of treatment, the fat attenuation parameters of the two groups were significantly decreased compared with those before treatment, and the difference was statistically significant (p < 0.05). The fat attenuation parameters in the treatment group were significantly lower than those in the control group at 12 and 24weeks after treatment (p < 0.05). Conclusion: The effect of Ganshuang granule combined with antiviral drugs in the treatment of chronic hepatitis B complicated with non-alcoholic fatty liver is significantly better than that of antiviral drugs alone, which is worthy of clinical recommendation. Systematic Review Registration: https://register.clinicaltrials.gov, identifier NCT05523648.

Green Nanoemulsion Water/Ethanol/Transcutol/LabM-Based Treatment of Pharmaceutical Antibiotic Erythromycin-Contaminated Aqueous Bulk Solution.

Contaminated wastewater released from hospital, domestic, and industrial sources is a major challenge to aquatic animals and human health. In this study, we addressed removal of erythromycin (ERN) from contaminated water employing water/ethanol/Transcutol/Labrafil M 1944 CS (LabM) green nanoemulsions as a nanocarrier system. ERN is a major antibiotic contaminant harming aquatic and human lives. Green nanoemulsions were prepared and evaluated for size, size distribution (measuring polydispersity index), stability, zeta potential, refractive index, and viscosity. Transmission electron microscopy (TEM) was used to visualize morphological behavior. The treated-water was analyzed for ERN by the spectroscopy, scanning electron microscopy-energy-dispersive X-ray analysis mode (SEM-EDX), and inductively coupled plasma-optical emission spectroscopy (ICP-OES) techniques. We studied factors (composition, size, viscosity, and time of exposure) affecting removal efficiency (%RE). The obtained green nanoemulsions (ENE1-ENE5) were stable and clear (<180 nm). ENE5 had the smallest size (58 nm), a low polydispersity index value (0.19), optimal viscosity (∼121.7 cP), and a high negative zeta potential value (-25.4 mV). A high %RE value (98.8%) was achieved with a reduced size, a high water amount, a low Capryol 90 content, and optimal viscosity as evidenced by the obtained results. Moreover, contact time had insignificant effect on %RE. UV-vis spectroscopy, SEM-EDX, and ICP-OES confirmed the absence of ERN from the treated water. Conclusively, ERN can easily be removed from polluted water employing green nanoemulsions prepared from the optimized excipients, and evaluated characteristics.

Social Structure and Temporal Distribution of Tursiops truncatus in the Gulf of Taranto (Central Mediterranean Sea)

This study aims to provide information on the site fidelity, residency patterns and the social structures of bottlenose dolphins occurring in the Gulf of Taranto in order to supply effective indications supporting the future management and conservation measures of the species. Out of 141 photo-identified individuals about 76% were re-sighted from 2 up to 31 times. The site fidelity analysis of photo-identified individuals highlighted the occurrence of 20 seasonal residents, 62 visitors and 59 transient individuals that were included in a local population in which emigration and reimmigration events occurred, as suggested by the residency-pattern analysis. The association pattern, performed using SOCPROG 2.9, highlighted a relatively low mean value of the overall half-weight association index (0.11 ± 0.04). However, the test for the null hypothesis of ‘random association’ was rejected and the temporal analysis made with SLAR suggested the presence of both extremely fluid and stable associations between individuals, describing a fission fusion social structure with a certain degree of social organization. Moreover, the cluster and social network analysis showed two geographically and socially segregated units. Thus, more investigations are needed and the development of a specific conservation plan for bottlenose dolphins in the whole area is required.

Definition of starch components in foods by first-order kinetics to better understand their physical basis

Starch-based foods frequently contain different starch digestible fractions, with distinct digestion rates and locations in human upper gastrointestinal tract. Understanding the physical basis for these starch components is critical for developing foods with low glycemic index (GI) values. Conducting first-order kinetics analysis has been able to extract information on starch digestion properties, with solid physical basis. However, there is currently no clear procedure in terms of defining different starch fractions by first-order kinetics analysis. This review proposes that starch-based foods can be categorized as structurally homogenous or heterogenous starch systems by fitting their starch digestograms to the first-order kinetics model, which are characterized by a single set or multiple sets of digestion rate constants and the fractions remaining undigested at long times during in vitro digestion. In line with starch hierarchical structures, it helps understand the structural origins for different starch components in foods, which can ultimately help the development of functional foods with low GI. Procedure to identify the starch fractions in starch-based foods to better understand their physical basis. SF is single fraction. RDF represents rapidly digestible starch fraction, while SDF represents slowly digestible starch fraction. • Starch-based foods often contain multiple starch fractions. • These foods can be defined as structurally homogeneous or heterogenous foods. • This definition helps the understanding of physical basis for starch digestibility.

VEGFA165‐induced persistent impairment of the retinal endothelial cells' barrier only transiently depends on the growth factor's action

AbstractRetinal endothelial cells (REC) form a stable barrier persistently disrupted by exposure to 1.2 nM VEGFA165 at least for up to 9 days. Such impairment – associated with persistently low cell index values assessed as a measure of permeability and low expression or loss of plasma membrane presence of tight‐junction protein claudin‐1 – can be completely prevented by binding VEGFA or by preventing VEGFA‐driven signal transduction. When added to REC exposed to VEGFA165 for 1 day, VEGF‐binding proteins or inhibitors of VEGF receptor 2 completely but only transiently revert these disturbances induced by the growth factor not improved by addition of a second portion of the VEGFA antagonist. This inhibition is – if ever – only partially successful after addition of the inhibitors to cells exposed to VEGFA for 3 or 6 days. VEGFA concentrations in the supernatant of VEGFA‐exposed cells decline from 0.6 nM 2 days after addition to 0.1 nM after 9 days which is below the threshold necessary to induce a barrier disturbance. Free VEGFA is also not present in the supernatant of cells exposed to the growth factor and its antagonists, and other permeability‐inducing cytokines, i.e. TNFalpha, IL‐6 or IL‐8, are also not secreted during exposure to VEGFA165 for 9 days. Taken together, disturbances of para‐ and transcellular flow can be prevented or reverted by blocking VEGFA‐driven signal transduction only early during exposure, because persistent changes no longer depend on the growth factor's action.

Dry and Wet Changes and Vegetation Time-Delay Responses in Western China

Due to global warming and other climate changes, it is increasingly important to study the response of regional environmental changes and dynamic changes in vegetation to climate change. Based on meteorological data from the last 60 years, this paper calculates the humidity index of western China under a wide range of long time series in different regions and explores the cross-correlation effect between series by offering a comparison with NDVI data, to analyze the cross-correlation between wet and dry changes and changes in vegetation in western China on a spatial scale. The results show that the spatial distribution of the interdecadal humidity index is different between different regions in western China. For example, the semi-arid and the semi-humid zones of the Weihe River region exhibit significant changes, while the Xinjiang and Qinghai–Tibet regions show a trend of constant wetness, on the whole, and the Sichuan and Yunnan–Guizhou regions are relatively humid and the distribution of wetness and dryness is relatively stable. The distribution of high and low values of the humidity index is very obvious and consistent with that of the distribution of desert bare land and precipitation in western China. In common with the distribution in the humidity index, the maximum correlation number between the NDVI and the humidity index in the whole western region is also significantly different in spatial distribution. There is a positive correlation between the NDVI and the humidity index in 99% of the study area. However, the delay in response time of the NDVI to changes in the humidity index in each region is inconsistent. For example, changes in the NDVI lag changes in the humidity index in the Menggan region by generally either 2 months or 5 months, while in the Sichuan region the delay in response time is generally 3 months. The variation and trend in dry and wet areas are closely related to the geographical location, climate zone, and topographic terrain, which may be the reason for the differences in the distribution of vegetation types and the response time to dry and wet changes. There is significant interaction between the humidity index and the vegetation type or precipitation distribution in western China. The positive correlation between the NDVI and the humidity index means that the positive effect is more sensitive, and the response of grassland is the most sensitive in the ecosystem.

Spatiotemporal dynamics of ecological security in a typical conservation region of southern China based on catastrophe theory and GIS.

Ecological security assessment can effectively reflect the ecological status of a region and reveal its level of sustainable development. In this paper, an ecological security-oriented evaluation system was constructed, and the ecological security level of the Dongjiangyuan region from 2000 to 2020 was evaluated based on catastrophe theory and GIS. The results were as follows: (1) As shown in the land use and cover maps, by 2020, the forestland area had decreased the most, and the artificial surface area had increased the most. (2) The ecological security index of the Dongjiangyuan region showed a low trend in the artificial surface area and its surrounding areas. The quite low values of the ecological security index in 2000 and 2010 were improved in 2020 due to the increase in ecological services capacity. The increased vegetation cover from 2000 to 2020 promoted the improved ecological service capacity. (3) The rapid urbanization process in the Dongjiangyuan region resulted in a lower ecological sensitivity index value. Notably, the ecological sensitivity index of the study area had a slightly decreasing trend. (4) The spatial autocorrelation showed that the proportion of hot and cold spots from 2000 to 2020 decreased by 2.96% and 6.91%, respectively. This study can provide a scientific basis and decision-making guidance for ecological management in the Dongjiangyuan region in the future.

A Switched Capacitor-Based 13-Level Inverter With Reduced Switch Count

In this article, a 13-level switched capacitor multilevel inverters (SC-MLI) based single-phase inverter is proposed in which desired levels of output ac voltage are realized with reduced number of switch counts. The proposed inverter requires 12 switches, three diodes, one input dc source, and three capacitors. The requirement of less number of switches reduces the requirement of gate drivers, which enhances power density of converter. The second challenge in SC-MLI is to maintain self-voltage balancing across the capacitors. The self-voltage balancing capability becomes poor at low values of modulation index. The capacitors connected in proposed SC-MLI are capable to maintain the self-voltage balancing without requiring auxiliary circuits or complex control strategies. The operation of capacitors is self-balanced at all regions of modulation index values. The comparison of the proposed SC-MLI is carried out with state-of-art SC-MLIs discussed in the literature using the parameters like peak inverse voltage and total standing voltage. The switches connected in the proposed 13-level SC-MLI undergoes less voltage stress as compared to the SC-MLI configurations discussed in the literature. The proposed SC-MLI is highly competent to achieve good power quality and is capable to ensure voltage balancing of capacitors even at low values of modulation index. The validation of the proposed inverter topology is carried out using a laboratory prototype. The efficiency of the converter claimed using the simulation results is observed to be 96.2% while the efficiency evaluated using the experimental results is 94.1% at 500 W.