Novel artificial intelligence assisted Landsat-8 imagery analysis for mango orchard detection and area mapping.

The mango fruit plays a crucial role in providing essential nutrients to the human body and Pakistani mangoes are highly coveted worldwide. The escalating demand for agricultural products necessitates enhanced methods for monitoring and managing agricultural resources. Traditional field surveys are labour-intensive and time-consuming whereas remote sensing offers a comprehensive and efficient alternative. The field of remote sensing has witnessed substantial growth over time with satellite technology proving instrumental in monitoring crops on a large scale throughout their growth stages. In this study, we utilize novel data collected from a mango farm employing Landsat-8 satellite imagery and machine learning to detect mango orchards. We collected a total of 2,150 mango tree samples from a farm over six months in the province of Punjab, Pakistan. Then, we analyzed each sample using seven multispectral bands. The Landsat-8 framework provides high-resolution land surface imagery for detecting mango orchards. This research relies on independent data, offering an advantage for training more advanced machine learning models and yielding reliable findings with high accuracy. Our proposed optimized CART approach outperformed existing methods, achieving a remarkable 99% accuracy score while the k-Fold validation score also reached 99%. This research paves the way for advancements in agricultural remote sensing, offering potential benefits for crop management yield estimation and the broader field of precision agriculture.

Current research hotspots and frontier trends on carbon budget of coastal wetlands: A bibliometric analysis.

Coastal wetlands are the main distribution of blue carbon in coastal zones and well known for their high carbon sequestration capacity. Investigating the variation of carbon budget is crucial for understanding the functionality of coastal wetlands and effectively addressing climate change. In this study, a bibliometric analysis of 4,509 articles was conducted to reveal research progress, hot issues, and emerging trends in the coastal wetland carbon budget field. The number of publications and citations in this field increased exponentially from 1991 to 2022. The leading subject category was Environmental Sciences with 1,844 articles (40.9%). At present, studies have been focused on blue carbon, the effects of climate change and man-made disturbances on carbon cycle, and the restoration of coastal wetlands. Based on the hotspots and trends in this field, the future researches should include (1) exploring the functional mechanisms of various factors affecting carbon cycle and establishing a methodological system for the estimation of blue carbon in coastal wetlands; (2) researching restoration techniques of coastal wetland and constructing wetland restoration evaluation index system; and (3) formulating enforceable carbon trading policy and strengthening international cooperation.

Characteristics and mechanisms of phosphine production in sulfur-based constructed wetlands.

Phosphine (PH3) is an important contributor to the phosphorus cycle and is widespread in various environments. However, there are few studies on PH3 in constructed wetlands (CWs). In this study, lab-scale CWs and batch experiments were conducted to explore the characteristics and mechanisms of PH3 production in sulfur-based CWs. The results showed that the PH3 release flux of sulfur-based CWs varied from 0.86±0.04 ng·m-2·h-1 to 1.88±0.09 ng·m-2·h-1. The dissolved PH3 was the main PH3 form in CWs and varied from 2.73 µg·L-1 to 4.08 µg·L-1. The matrix-bound PH3 was a staging reservoir for PH3 and increased with substrate depth. In addition, the sulfur-based substrates had a significant improvement on PH3 production. Elemental sulfur is more conducive to PH3 production than pyrite. Moreover, there was a significant positive correlation between PH3 production, the dsrB gene, and nicotinamide adenine dinucleotide (NADH). NADH might catalyze the phosphate reduction process. And the final stage of the dissimilatory sulfate reduction pathway driven by the dsrB gene might also provide energy for phosphate reduction. The migration and transformation of PH3 increased the available P (Resin-P and NaHCO3-P) from 35 % to 56 % in sulfur-based CW, and the P adsorption capacity was improved by 12 %. The higher proportion of available P increased the plant uptake rate of P by 17 %. This study improves the understanding of the phosphorus cycle in sulfur-based CW and provides new insight into the long-term stable operation of CWs.

Autophagy related genes mediated mitophagy in yeast, mammals and higher plants.

Autophagy is classified into macro-autophagy and micro-autophagy. Two major types of autophagy in the complex eukaryotic organism are microautophagy and macroautophagy. During microautophagy, cytoplasmic components that need to be degraded are taken up by lysosomes in animals and by vacuole in yeast and plants via the invagination of tonoplast. While macroautophagy is initiated after the formation of a cup-shaped membrane structure, a phagophore develops at cargo that grows in size and is sealed by double-membrane vesicles to form autophagosome; a generalized mechanism for degradation of the organelle. Autophagic removal of damaged mitochondria is a conserved cellular process to maintain a healthy mitochondrion called Mitophagy. In plants and animals, mitophagy has crucial roles in stress responses, senescence, development, and programmed cell death. Mitophagy appears in mammals, fungi, and plants but many genes that controlled mitophagy are absent from plants. Numerous studies have been conducted by using ATG mutants for the identification of functional roles of Autophagy Related Genes (ATG) required during the autophagy process at various steps like; auto phagosome formation, ATG protein recruitment, etc. The role of more than 25 ATG genes in mitophagy has been discussed in this review paper. The main parameters, reviewed and summarized in this review paper, are the name of species, common name, function, domain, deletion, induction, and localization of these autophagy-related genes in the cell. This review will facilitate the students, researchers, and academics for their further research insights.

New insights for simultaneous nutrient removal enhancement and greenhouse gas emissions reduction of constructed wetland by optimizing its redox environment through manganese oxide addition.

Manganese oxide (MnOx) is receiving increased interest in the nutrient removal of constructed wetlands (CWs); however, its service effectiveness for simultaneous greenhouse gas (GHG) emissions reduction is still vague. In this study, three vertical flow CWs, i.e., volcanics (CCW), manganese sand uniformly mixing with volcanics (Mn-CW) and MnOx doped volcanics (MnV-CW), were constructed to investigate the underlying mechanisms of MnOx on nutrient removal enhancement and greenhouse gas (GHG) emissions reduction. The results showed that the MnOx doped volcanics optimized the oxidation-reduction potential surrounding the substrate (-164.0 ∼ +141.1 mv), and resulted in the lowest GHG emissions (CO2-equivalent) from MnV-CW, 16.8-36.5 % lower than that of Mn-CW and CCW. This was mainly ascribed to mitigation of N2O produced during the NO3--N reduction process, according to results of 15N stable isotope labeling. Analysis of the microbial community structure revealed that due to the optimized redox conditions through chemical doping of MnOx on volcanics, the abundance of microbe involved in denitrification and Mn-oxidizing process in the MnV-CW was significantly increased at genus level, which led to a higher Mn cycling efficiency between biogenic MnOx and Mn2+, and enhanced denitrification efficiency and N2O emission reduction. This study would help to understand and provide a preferable reference for future applications for manganese-based CW.

Neuropsychiatric Disorders: Bridging the Gap Between Neurology and Psychiatry.

Given the ongoing difficulties faced by clinicians and researchers in dealing with neuropsychiatric illnesses, it is becoming more and more evident that there is a need to go beyond traditional disciplinary boundaries. This research consolidates existing material, examining changes in history, the fundamental neurobiological aspects, and the shared clinical manifestations between neurology and psychiatry. This inquiry examines the historical development of neuropsychiatry, focusing on the relationship between early understandings of mental illness and the later division of neurology and psychiatry. The focus is on recent advancements in comprehending the common neurobiological pathways and genetic factors that highlight the merging of these fields. The research highlights the complexities of clinical presentations in neuropsychiatric illnesses by analyzing the overlapping cognitive, affective, and behavioral symptoms. The text critiques the diagnostic issues in traditional frameworks, emphasizing the limitations in differentiating between neurological and psychiatric origins. This has ramifications for achieving correct diagnosis and arranging appropriate treatment. The paper explores developing multidisciplinary care approaches, highlighting successful collaborations between neurologists and psychiatrists. This study examines the difficulties in carrying out a plan and the process of identifying obstacles to combining different elements. It also highlights the urgent need for improved instruction and learning for smooth cooperation. The paper examines the therapeutic implications by investigating pharmacological therapies focusing on shared pathways. It also discusses the difficulties involved in managing neurological and psychiatric diseases that occur together. The study also explores non-pharmacological therapies, such as psychotherapy and rehabilitation methods, as part of a comprehensive treatment approach. Anticipating the future, the report identifies areas where the study could be improved and forecasts the influence of technological improvements on the subject. Suggestions are put out to encourage additional exploration, cooperation, and originality to narrow the divide between neurology and psychiatry, ultimately augmenting our comprehension and treatment of neuropsychiatric illnesses. This real-time synthesis adds to the ongoing discussion, providing valuable insights that align with the ever-changing field of contemporary neuropsychiatric research and therapy.

Is constructed wetlands carbon source or carbon sink? Case analysis based on life cycle carbon emission accounting.

Constructed wetlands (CWs) are widely used to polish the effluent of wastewater treatment plants and micro-polluted river or lake water. However, the impact of large-scale applications of CWs on carbon emissions is unclear. In this study, the carbon footprints of two full-scale hybrid CWs were determined based on life cycle assessment (LCA). Results showed that the carbon emission of CW ranged from 0.10 to 0.14 kg CO2-eq/m3, and was significantly correlated with the influent chemical oxygen demand loads and electricity consumption. However, CW would approach carbon neutrality during the service period when taking plant carbon sequestration into consideration. Compared with other advanced wastewater treatment technologies, CWs showed significant low-carbon emission and cost-effective benefits. This study clarified the role of CWs in the carbon cycle and would provide guidance for the construction and management of CWs.

Seasonality, epidemiology and phylogeny of Theileria ovis with a note on hematological and biochemical changes in asymptomatic infected goats from Pakistan.

Caprine theileriosis, caused by Theileria ovis is a serious production issue, especially in the areas that depend on goats and sheep for milk, meat, and other economic benefits. Pakistan has a large goat population, but few reports have been documented from this country regarding PCR-based detection of T. ovis. The molecular prevalence of T. ovis, on a seasonal basis, in various goat breeds enrolled from Muzaffar Garh district of Punjab in Pakistan was determined from October 2018 to September 2019. In this study, 1084 goat blood samples were screened for the detection of T. ovis DNA through PCR-based amplification of 18S rRNA gene. Out of 1084 goats, 12 (1.11%) were infected with T. ovis. The parasite prevalence varied with the sampling seasons (Chi square test, P = 0.008), and the parasite prevalence was highest in goat blood samples collected in summer (2.39%) followed by winter (1.88%). DNA sequencing and BLAST analysis confirmed the presence of T. ovis, and the amplified isolates from the 18S rRNA gene of T. ovis were found to be highly conserved during phylogenetic analysis. Young goats (Fischer exact test, P = 0.022) were found more infected with T. ovis during the winter season. Infected goats had elevated white blood cell counts (Two-sample t-test, P = 0.04), blood urea nitrogen to Creatinine ratio (Two-sample t-test, P = 0.02) and decreased serum Creatinine (Two-sample t-test, P = 0.001) as compared to T. ovis negative goats. We report a relatively low molecular prevalence of T. ovis in goats from the Muzaffar Garh district. However, it is recommended that control measures to eradicate T. ovis infection in goats in this area should be taken.

Microplastics: unraveling the signaling pathways involved in reproductive health.

Microplastics (MPs) are biologically active environmental pollutants having significant impact on the ecosystem and human health. MPs have been reported to increase oxidative stress, resulting in tissue damage, developmental abnormalities, metabolic disorders, epigenetic changes, abnormal reproduction, and reduced gamete quality. At present, most of the existing literature has focused on the effects of MPs on the reproduction of various aquatic organisms; however, the effects of MPs on mammalian reproduction specifically humans are least studied except a few ones fragmentally discussing the effects of MPs on gametogenesis in human. This review discusses effects of MPs on male and female reproduction with a focus on different metabolic pathways involved in compromised gamete quality, gamete toxicity, apoptosis, and DNA damage.

Genome-wide identification and expression profiling of two-component system (TCS) genes in Brassica oleracea in response to shade stress.

The Two-component system (TCS) consists of Histidine kinases (HKs), Phosphotransfers (HPs), and response regulator (RR) proteins. It has an important role in signal transduction to respond to a wide variety of abiotic stresses and hence in plant development. Brassica oleracea (cabbage) is a leafy vegetable, which is used for food and medicinal purposes. Although this system was identified in several plants, it had not been identified in Brassica oleracea yet. This genome-wide study identified 80 BoTCS genes consisting of 21 HKs, 8 HPs, 39 RRs, and 12 PRRs. This classification was done based on conserved domains and motif structure. Phylogenetic relationships of BoTCS genes with Arabidopsis thaliana, Oryza sativa, Glycine max, and Cicer arietinum showed conservation in TCS genes. Gene structure analysis revealed that each subfamily had conserved introns and exons. Both tandem and segmental duplication led to the expansion of this gene family. Almost all of the HPs and RRs were expanded through segmental duplication. Chromosomal analysis showed that BoTCS genes were dispersed across all nine chromosomes. The promoter regions of these genes were found to contain a variety of cis-regulatory elements. The 3D structure prediction of proteins also confirmed the conservation of structure within subfamilies. MicroRNAs (miRNAs) involved in the regulation of BoTCSs were also predicted and their regulatory roles were also evaluated. Moreover, BoTCSs were docked with abscisic acid to evaluate their binding. RNA-seq-based expression analysis and validation by qRT-PCR showed significant variation of expression for BoPHYs, BoERS1.1, BoERS2.1, BoERS2.2, BoRR10.2, and BoRR7.1 suggesting their importance in stress response. These genes showing unique expression can be further used in manipulating the plant's genome to make the plant more resistant the environmental stresses which will ultimately help in the increase of plant's yield. More specifically, these genes have altered expression in shade stress which clearly indicates their importance in biological functions. These findings are important for future functional characterization of TCS genes in generating stress-responsive cultivars.

Genomic Determinants of Pathogenicity and Antimicrobial Resistance of Nosocomial Acinetobacter baumannii Clinical Isolates of Hospitalized Patients (2019-2021) from a Sentinel Hospital in Hangzhou, China.

Purpose: Acinetobacter baumannii (A. baumannii or AB) is one of the most opportunistic, nosocomial pathogens threatening public healthcare across countries. A. baumannii has become a primary growing concern due to its exceptional ability to acquire antimicrobial resistance (AMR) to multiple antimicrobial agents which is increasingly reported and more prevalent every year. Therefore, there is an urgent need to evaluate the AMR knowledge of A. baumannii for effective clinical treatment of nosocomial infections. This study aimed to investigate the clinical distribution AMR phenotypes and genotypes, and genomic characteristics of A. baumannii isolates recovered from hospitalized patients of different clinical departments of a sentinel hospital to improve clinical practices. Methods: A total of 123 clinical isolates were recovered from hospitalized patients of different clinical departments during 2019-2021 to analyze AMR patterns, and further subjected to whole-genome sequencing (WGS) investigations. Multi-locus sequence typing (MLST), as well as the presence of antimicrobial-resistant genes (ARGs), virulence factor genes (VFGs) and insertion sequences (ISs) were also investigated from WGS data. Results: The results highlighted that A. baumannii clinical isolates had shown a high AMR rate, particularly from the intensive care unit (ICU), towards routinely used antimicrobials, ie, ß-lactams and fluoroquinolones. ST2 was the most prevalent ST in the clinical isolates, it was strongly associated to the resistance of cephalosporins and carbapenems, with blaOXA-23 and blaOXA-66 being the most frequent determinants; moreover, high carrier rate of VFGs was also observed such as all strains containing the ompA, adeF, pgaC, lpsB, and bfmR genes. Conclusion: Acinetobacter baumannii clinical isolates are mostly ST2 with high rates of drug resistance and carrier of virulence factors. Therefore, it requires measurements to control its transmission and infection.

LACP-SG: Lightweight Authentication Protocol for Smart Grids.

Smart grid (SG) recently acquired considerable attention due to their utilization in sustaining demand response management in power systems. Smart meters (SMs) deployed in SG systems collect and transmit data to the server. Since all communications between SM and the server occur through a public communication channel, the transmitted data are exposed to adversary attacks. Therefore, security and privacy are essential requirements in the SG system for ensuring reliable communication. Additionally, an AuthentiCation (AC) protocol designed for secure communication should be lightweight so it can be applied in a resource-constrained environment. In this article, we devise a lightweight AC protocol for SG named LACP-SG. LACP-SG employs the hash function, "Esch256", and "authenticated encryption" to accomplish the AC phase. The proposed LACP-SG assures secure data exchange between SM and server by validating the authenticity of SM. For encrypted communication, LACP-SG enables SM and the server to establish a session key (SEK). We use the random oracle model to substantiate the security of the established SEK. Moreover, we ascertain that LACP-SG is guarded against different security vulnerabilities through Scyther-based security validation and informal security analysis. Furthermore, comparing LACP-SG with other related AC protocols demonstrates that LACP-SG is less resource-intensive while rendering better security characteristics.

Gender equality, education, economic growth and religious tensions nexus in developing countries: A spatial analysis approach.

Gender inequality is a more pronounced phenomenon in developing countries, which may be rooted in poor governance, and inadequate social and religious institutions. Therefore, this research tests the effects of religious tensions, governance, economic growth, and education on gender equality in a panel of 59 developing countries from 1995-2015. Moreover, religious tensions may have spillovers in neighboring countries in this modern age of media and globalization. Therefore, we apply Spatial Durbin and Autoregressive models to consider spatial autocorrelation in the religious tensions model. We find that both gender equality and religious tensions have spillovers in neighboring countries. Moreover, reducing religious tensions and increasing economic growth promote gender equality and have positive spillovers in neighboring countries as well. Bureaucratic quality has a positive effect on gender equality in home countries and has insignificant spillovers on gender equality in the neighboring countries. However, education could not affect gender equality in developing countries.

Waste management and green technology: future trends in circular economy leading towards environmental sustainability.

The effective treatment of waste to be used as a resource in future has a major role in achieving environmental sustainability and moving towards circular economy. The current research is aimed to provide in-depth detail regarding prominent trends and research themes, evolution, future research orientation, main characteristics, and mapping of research publications on waste management, technological innovation in circular economy domain from the year 2000 to 2021. Different analyses including text mining and bibliometric and content analyses were applied to answer the research question and provide the details on aforementioned variables. From the bibliometric analyses, a total of 1118 articles were drawn out from the Scopus database to conceptualize the core body of research. As a result, the following themes were identified: electronic waste, circular economy transition, plastic waste, bio-based waste management, lifecycle assessment, and ecological impacts, and construction and demolition waste management. The highlighted features, future research orientation, and prominent research perspective can provide guideline for future research to enrich the literature through conducting studies on provided research directions and help lead waste management and technological innovation policymakers, professionals, and practitioners in moving towards circular transition.

Sustainable supply chain management and green technologies: a bibliometric review of literature.

To attain ecological sustainability and transition to sustainable supply chain management (SSCM), effective technological innovation (TI) and solid waste management (SWM), as likely impending resources, are essential components. From 2000 through 2021, a detailed map of SSCMs in the context of TI and systematic history will be created, highlighting the most significant research themes and trends, primary features, development, and possibly relevant areas for future study. Due to utilizing bibliometric analysis, text mining, and content analytics methodologies, the following concerns were addressed: (1) How has SSCM research progressed over time in the TI domain? (2) Which SSCM research areas and trends receive the most attention in the TI domain? Additionally, (3) what are the research directions for SSCM in the context of TI? As a result, bibliometric networks were developed and examined using 983 journal articles from the Scopus database to highlight the substantial body of literature. As a result, SSCM has been divided into five crucial study themes: (i) transition to TI, (ii) SSCM in closed-loop supply chains, (iii) municipal solid waste management (MSWM), (iv) environmental consequences and life-cycle evaluation, and (v) policymakers and practitioners in SSCM can use the SSCM research landscape and its primary highlight patterns to guide and add in the TI. Considering SSCM research as a way to reduce waste, future study directions are also suggested.

Molecular prevalence, associated risk factors and phylogeny of Anaplasma marginale, Theileria ovis and T. lestoquardi in sheep from Pakistan.

Anaplasma marginale, Theileria ovis and Theileria lestoquardi are intracellular pathogens that infect a wide variety of animals and cause enormous economic losses worldwide. The present investigation aims to report the occurrence and the phylogeny of these pathogens infecting sheep (N = 330) from Rajanpur District in Punjab (Pakistan) by using msp1b gene for A. marginale and 18 S rRNA for T. ovis and T. lestoquardi. Results revealed that prevalence rates of A. marginale, T. ovis and T. lestoquardi were 7.3%, 6.1% and 1.2%, respectively. Four (1.2%) and one (0.3%) sheep were found to be co-infected with two and three pathogens, respectively. Risk factor analysis revealed that rams were more infected with A. marginale compared to ewes (P = 0.015). In addition, it was observed that animals located in herds having dogs and those in small herds were found more infected, respectively, with T. ovis (P = 0.001) and T. lestoquardi (P = 0.009). Phylogenetic analysis revealed that Pakistani isolates of each detected pathogens clustered together and were closely related to other Pakistani isolates and those from worldwide countries such as Iran, Iraq, Turkey, Sudan, Tanzania, South Africa, and USA. This is the first molecular study reporting the natural infection of Pakistani sheep with these three pathogens. These data need to be taken into account in order to improve the productivity of the livestock sector which is one of main sources of income in the country.

Nexuses between crude oil imports, renewable energy, transport services, and technological innovation: a fresh insight from Germany.

This research attempts to model the association of crude oil imports with several macroeconomic factors such as renewable energy, transport services, trade, industrial value-added, and patents, using Germany's annual data covering the period of 1990-2020. Employing the Autoregressive Distributed Lag model, this study finds a significant co-integration relationship among targeted variables. Moreover, this study provides empirical evidence on the influence of given macroeconomic factors in determining crude oil imports of Germany. Results reveal that transport services and industrial value-added positively and significantly influence crude oil imports in the long and short run. Similarly, trade is discovered to have a significant positive impact on oil imports only in the long run. In contrast, findings reveal a significant negative association of renewable energy with crude oil imports. Hence, this research implies that the transportation sector and industrial production strongly depend on crude oil consumption. At the same time, promoting renewable energy in these segments could significantly help economies control crude oil demand and achieve sustainability by reducing the economic burden and protecting the environment.

Deep learning-based optimization of a microfluidic membraneless fuel cell for maximum power density via data-driven three-dimensional multiphysics simulation.

A deep learning-based method for optimizing a membraneless microfluidic fuel cell (MMFC)performance by combining the artificial neural network (ANN) and genetic algorithm (GA) was for the first time introduced. A three-dimensional multiphysics model that had an accuracy equivalent to experimental results (R2 = 0.976) was employed to generate the ANN's training data. The constructed ANN is equivalent to the simulation (R2 = 0.999) but with far better computation resource efficiency as the ANN's execution time is only 0.041 s. The ANN model is then used by the GA to determine the inputs (microchannel length = 10.040 mm, width = 0.501 mm, height = 0.635 mm; temperature = 288.210 K, cell voltage = 0.309 V) that lead to the maximum power density of 0.263 mWcm-2 (current density of 0.852 mAcm-2) of the MMFC. The ANN-GA and numerically calculated maximum power densities differed only by 0.766%.

Genetic diversity, virulence factors, and antimicrobial resistance of Listeria monocytogenes from food, livestock, and clinical samples between 2002 and 2019 in China.

Listeria monocytogenes remains a significant public health threat, leading to invasive listeriosis with severe manifestations (i.e. septicemia, meningitis, and abortion) and up to 30% of fatal cases. Here, we aimed to investigate genotypic diversity, virulence profiles, antimicrobial resistance patterns from a large and integrated population of L. monocytogenes isolates in China (n = 369), including food (n = 326), livestock (n = 25), and hospitalized humans (n = 18) over the years (2002-2019). PCR-based serogrouping showed the dominance of serogroup 1/2a-3a (37.4%) in food, 4a-4c (76%) in livestock, and 1/2a-3a (44.4%) in humans. Phylogenetic lineage analysis revealed the dominance of lineage II (63.4%) in food, lineage III (76%) in livestock, and lineage II (55.5%) in humans. Altogether, 369 isolates were grouped into 55 sequence types (STs) via multi-locus sequence typing (MLST), which belonged to 26 clonal complexes (CCs) and 17 singletons. Among various STs, ST9 (26%) was the most abundant in food, ST202 (76%) in livestock, and ST8 (16.6%) in humans. Overall, ST4/CC4, ST218/CC218, and ST619 isolates harbored both LIPI-3 and LIPI-4 genes subsets indicating their hypervirulence potential. Additionally, a low resistance was observed towards tetracycline (5.1%), erythromycin (3.2%), cotrimoxazole (2.9%), chloramphenicol (2.7%), gentamicin (2.4%), and ampicillin (2.1%). Collectively, detection of hypervirulent determinants and antimicrobial-resistant phenotype among Chinese isolates poses an alarming threat to food safety and public health, which requires a continued and enhanced surveillance system for further prevention of human listeriosis.