Magnitude Of Variation Research Articles

The Significance of Thiophene in Medicine: A Systematic Review of the Literature

Thiophene nucleus has been established as the potential entity in the largely growing chemical world of heterocyclic compounds possessing promising pharmacological characteristics. The similar compounds synthesized through different routes bear variable magnitudes of biological activities.. An odor reminiscent of benzene characterizes this colorless liquid. It exhibits a majority of its reactions resembling those of benzene. Thiophene has a structure that is analogous to structure of pyrrole, and due to pie electron cloud, it behave like extremely reactive benzene derivative. The available analytical and informational data in literature indicate Thiophene constitute a notable class of chemicals in the medical domain, exhibiting a range of therapeutic potentials. These encompass antiviral, antimalarial, antihypertensive, antimicrobial, antioxidant anticonvulsant, anticancer, anti-inflammatory, antidepressant and antimycobacterial, properties. An examination of reveals literature that the moiety thiophene has garnered considerable attention from medicinal chemists and biochemists to formulate, design, and implement novel approaches for the discovery of new pharmaceuticals. This review article confirms that thiophene derivatives have the potential to be a valuable resource for developing new biologically active compounds. It is prudent to investigate this possibility by combining various substituted components, as this may lead to improved pharmacological effects. Therefore, it is necessary to persist in the pursuit of investigating numerous further alterations on the thiophene moiety.

Electrochemical polymerization of o-phenylenediamine in the presence of metal salts: influence of Cu(NO3)2 and AgNO3 on spectroelectrochemical properties and morphology

In this study, the effects of adding Cu(NO3)2 and AgNO3 metal salts to the polymerization medium on the electrochemical and spectroelectrochemical properties of poly(o-phenylenediamine) (PoPD) were investigated. It was observed that the presence of Cu(NO3)2 or AgNO3 during polymerization increased the rate of current peak growth, indicating an acceleration of the polymerization process in the presence of metal ions. The cyclic voltammetry responses of the metal/polymer composites differed significantly from those of the pure polymer, confirming the formation of metal/polymer composites. FTIR and UV–vis absorption spectra were analyzed to explore the chemical structure of PoPD, PoPD/Cu, and PoPD/Ag polymer films. SEM and AFM analyses revealed distinct morphological differences between the polymer synthesized in the presence of metal salts and the pure polymer. Spectroelectrochemical analyses demonstrated that the polymer films exhibited reversible color changes from light copper to green, with distinct optical intensities in the UV–vis spectra. The absorbance and current values changed reversibly with the applied potential, with response times of approximately 10 s. Colorimetric analysis based on the CIE system showed unique variations in brightness (L), magnitude (a), and intensity (b) for PoPD, PoPD/Ag, and PoPD/Cu, confirming distinct colorimetric shifts during redox transitions. This study highlights the impact of Cu and Ag salts on the spectroelectrochemical and electrochromic performance of PoPD, revealing potential applications for PoPD composites in advanced electrochromic devices.

Comparing quantitative imaging biomarker alliance volumetric CT classifications with RECIST response categories.

To assess agreement between CT volumetry change classifications derived from Quantitative Imaging Biomarker Alliance Profile cut-points (ie, QIBA CTvol classifications) and the Response Evaluation Criteria in Solid Tumors (RECIST) categories. Target lesions in lung, liver, and lymph nodes were randomly chosen from patients in 10 historical clinical trials for various cancers, ensuring a balanced representation of lesion types, diameter ranges described in the QIBA Profile, and variations in change magnitudes. Three radiologists independently segmented these lesions at baseline and follow-up scans using 2 software tools. Two types of predefined disagreements were assessed: Type I: substantive disagreement, where the disagreement between QIBA CTvol classifications and RECIST categories could not be attributed to the improved sensitivity of volumetry in detecting changes; and Type II: disagreement potentially arising from the improved sensitivity of volumetry in detecting changes. The proportion of lesions with disagreements between QIBA CTvol and RECIST, as well as the type of disagreements, was reported along with 95% CIs, both overall and within subgroups representing various factors. A total of 2390 measurements from 478 lesions (158 lungs, 170 livers, 150 lymph nodes) in 281 patients were included. QIBA CTvol agreed with RECIST in 66.6% of interpretations. Of the 33.4% of interpretations with discrepancies, substantive disagreement (Type I) occurred in only 1.5% (95% CI: [0.8%, 2.1%]). Factors such as scanner vendor (P = .584), segmentation tool (P = .331), and lesion type (P = .492) were not significant predictors of disagreement. Significantly more disagreements were observed for larger lesions (≥50 mm, as defined in the QIBA Profile). We conclude that QIBA CTvol classifications agree with RECIST categories.

Determining the Nature of IC 10 X-2: A Comprehensive Study of the Optical/IR Emission from an Extragalactic BeHMXB

We present a comprehensive analysis of the optical and infrared (IR) properties of high-mass X-ray binary (HMXB) IC 10 X-2, classified as a supergiant HMXB and superfast X-ray transient by previous work. Our analysis of regular (daily and weekly) observations by both the Zwicky Transient Facility and Las Cumbres Observatory over a 5 yr period indicates both periodic flares and variations in the apparent magnitude and color with a period of ∼26.5 days—likely the orbital period of this binary system. The periodic flaring suggests the stellar companion is a Be star, with flares resulting from increased accretion onto the neutron star (NS) when it enters the stellar decretion disk. The periodic variations in the optical/IR brightness and color likely result from orbital variations in the hydrogen column density along the line of sight or a transient accretion disk around the NS. Lastly, the numerous short-duration episodes where IC 10 X-2 is significantly “redder” or “bluer” than normal likely result from clumps within this system—which can accrete onto the NS (causing IC 10 X-2 to appear bluer) or pass through the line of sight (causing IC 10 X-2 to appear redder). These results substantially increase our understanding of the evolution of this source, which is a significant source of ionizing photons in its host galaxy IC 10, a low-mass, metal-poor starburst galaxy similar in many respects to those thought to be common in the early Universe.

Experimental study on face stability of shield tunnel in water-rich inclined composite strata considering different inclination angles

Shield method has developed rapidly in the construction of underground or subsea tunnels. The stability of the tunnel excavation face is essential for the safe construction of tunnels, particularly in water-rich and inclined strata. The present study conducted shield model tests in water-rich inclined strata to analyze the surface settlement, ground earth pressure, areas of instability, and failure mechanism during the process of instability. The results indicate a decrease in settlement of the longitudinal monitoring points as the backward distance from the tunnel boundary line increases. Additionally, the settlement analysis of transverse monitoring sections reveals that the most significant settlement occurs directly above the tunnel. When equidistant from the tunnel excavation face, the surface settlement exhibits a significantly greater magnitude in front of it compared to behind it. The extent of influence is maximized when the inclination angle is negative, regardless of whether it pertains to the collapse in width or height on the surface. The application of DIC image analysis reveals that distinct failure mechanisms are observed for varying stratum inclination angles. The shear strain concentration becomes more pronounced with an increase in the backward distance, resulting in predominant distribution of shear bands in front of and above the tunnel. Compared to water-rich horizontal stratification or homogeneous soil layers, there are distinct variations in surface collapse magnitude, stratum disturbance range, and the instability mechanism of stratum instability in water-rich inclined strata. Therefore, when confronted with engineering projects involving inclined strata, it is imperative to consider the influence of geological factors.

Vertical and Lateral Variability of Suspended Sediment Transport in the Rhine River

ABSTRACTSuspended sediment is one of the major contributors to the total sediment load transported by rivers. Suspended sediment transport is highly variable both in time and space, driven by complex interactions between tectonics, climate change, and anthropogenic activity. Large waterways often underlie strong anthropogenic impact, for example, to ensure navigability and pursue economic objectives. However, stability and ecological integrity of the river system are equally important. For both, economic and ecologic objectives, processes related to the transport, deposition, and resuspension of fine sediment must be understood and quantified. Starting in the 1960s the Waterways and Shipping Administration (WSV) and the Federal Institute of Hydrology (BfG) started an extensive monitoring program to quantify suspended sediment transport in German navigable waterways. To cope with the large spatiotemporal variability of suspended sediment transport the WSV combined work‐daily single point measurements and infrequent multi‐point measurements. The aim of our study is to quantify the vertical and lateral variability of suspended sediment transport along the largest waterway in Germany, the Rhine River, and investigate drivers of cross‐sectional variability. We link results from multi‐point measurements with single‐point measurements to assess the representativity of surface samples compared to cross‐sectional means of suspended sediment concentration. The comparison of these two monitoring programs reveals that surface samples strongly underestimate suspended sediment loads. Main drivers that could be quantified are vertical gradients of suspended sediment concentration by means of Rouse profiles and lateral variability which is partially explained by mean channel curvature and related to the underestimation of suspended sediment transport relying on surface samples. Further, we observe that the magnitude of lateral variability is comparable to vertical variability, but often neglected in suspended sediment monitoring. Our study contributes to the refinement of existing monitoring schemes and shows how empirical data verifies and falsifies transport dynamics and processes.

Trait Association and Genetic Variability Study in Rice MAGIC Lines for Yield Related Traits

The study was aimed to assess genetic variability and associations between grain yield and morphological traits in 50 multi-parent advanced generation intercross (MAGIC) lines generated by single seed descent utilizing eight diverse parents (to impart tolerance to biotic and abiotic stresses) were utilized in the study along with eight checks at Zonal agricultural and horticultural research station, Navile, Shivamogga during kharif 2022. Improvement in grain yield, a quantitative trait is one of the key objective of plant breeders which depends upon the magnitude of genetic variability existing in the genetic material utilized in the breeding programme. The analysis of variance revealed the presence of significant differences were found among lines for all traits. Moderate to high genotypic and phenotypic variation, heritability and genetic advance were recorded for plant height, tillers per plant, filled grains per panicle, test weight and grain yield. Correlation analysis revealed positive associations between grain yield and tillers per plant, panicle length, filled grains per panicle, panicle fertility and test weight. These findings emphasize the importance of indirect selection for these traits to improve grain yield in rice. The results suggest that breeders can utilize these traits as selection criteria to enhance grain yield, ultimately contributing to rice yield improvement programs. Our study provides valuable insights for rice breeders to develop high-yielding rice varieties with improved tolerance to biotic and abiotic stresses.

Factors affecting self-care behaviours of ulcer prevention and glycemic control among diabetes mellitus patients at type A hospital in Yogyakarta

Background: One of the most detrimental complications of diabetic foot ulcers is largely influenced by glucose levels. To prevent diabetes-related complications and injuries, diabetic patients have to possess all the knowledge and behaviours required to perform regular self-care. Objective: This study aimed to identify factors that influence the behaviour of diabetic patients to prevent diabetic foot ulcers. Method: The study design was a cross-sectional survey of 57 outpatients with all criteria. The self-care knowledge and behaviour were measured by filling out questionnaires. A chi-square statistical test and multiple logistic regression were used to assess the magnitude of the predictor variables in behaviour and glycemic control. Moreover, difference tests were performed to assess differences between groups according to the level of behaviour. Result: Out of 57 participants, 29 patients were having poor self-care behaviour. Of the 28 patients with uncontrolled glycemic, 12 had poor behaviour. The knowledge scores between poor and moderate behaviour showed a statistically significant difference (p = 0.046). Knowledge had a 2-fold impact on behaviour (p = 0.025). Additionally, the type (p = 0.011) and the number (p = 0.040) of anti-diabetic medications in prescriptions affected glycemic control. Conclusion: Knowledge and behaviour of foot self-care and glycemic control are the key preventive factors.

THE WILLMORE ENERGY VARIATIONS AND ENERGY EFFICIENT ARCHITECTURE

Since the shape is an important feature of objects and can be immensely useful in characterizing objects, it should point out the shape analysis considering the variation of magnitudes that characterize the shape itself. One of the fundamental functionals that measure the bending of a surface is the Willmore energy. In view of the meaning of ruled surfaces in aesthetics, statics, scale and manufacturing technologies, we point out the possibility of a mathematical analysis in the case of infinitesimal deformations by considering the variations of the Willmore energy on Gaudi surface under infinitesimal bending in R3. Application could be connected with energy efficient building design.

The time of infection matters: seasonal interplay between host and pathogen drives epidemic dynamics

Host and pathogen dynamics are driven by seasonal variation, leading to complex epidemic patterns which are not well understood. Here, we linked demography and epidemiology in a single framework to reach a mechanistic understanding of disease dynamics in natural populations characterized by seasonality. We applied this approach to depict the interplay between a host, the wild boar, and a viral disease, African swine fever. This virus spreads in wild boar by direct‐contact among living individuals or though contacts with infected carcasses. In this system, both host and pathogen show seasonal patterns: survival and reproduction probabilities vary across the year in the wild boar, and virus persistence in the environment is affected by temperature which influences the speed of carcasses degradation. Using a stochastic individual‐based model, we showed that virus invasion success strongly varies according to the time of introduction due to the seasonal specific interaction between the virus and host. Furthermore, the shape of the following epidemic varies across seasons, with variation in speed and magnitude of the outbreak. Consequently, the host population response was also season‐specific, both regarding the speed of the decline and the change in population structure. Overall, our study highlights the inextricable connections between host, pathogen and the environmental dynamics, and the importance to consider each component to understand disease dynamics.

Exploring the Effects of Prefrontal Transcranial Direct Current Stimulation on Brain Metabolites: A Concurrent tDCS-MRS Study.

Transcranial Direct Current Stimulation (tDCS) is a non-invasive brain stimulation technique used to modulates cortical brain activity. However, its effects on brain metabolites within the dorsolateral prefrontal cortex (DLPFC), a crucial area targeted for brain stimulation in mental disorders, remain unclear. This study aimed to investigate whether prefrontal tDCS over the left and right DLPFC modulates levels of key metabolites, including gamma-aminobutyric acid (GABA), glutamate (Glu), glutamine/glutamate (Glx), N-acetylaspartate (NAA), near to the target region and to explore potential sex-specific effects on these metabolite concentrations. A total of 41 healthy individuals (19 female, M_age = 25 years, SD = 3.15) underwent either bifrontal active (2 mA for 20 min) or sham tDCS targeting the left (anode: F3) and right (cathode: F4) DLPFC within a 3 Tesla MRI scanner. Magnetic resonance spectroscopy (MRS) was used to monitor neurometabolic changes before, during, and after 40 min of tDCS, with measurements of two 10-min intervals during stimulation. A single voxel beneath F3 was used for metabolic quantification. Results showed a statistically significant increase in Glx levels under active tDCS compared to the sham condition, particularly during the second 10-min window and persisting into the post-stimulation phase. No significant changes were observed in other metabolites, but consistent sex differences were detected. Specifically, females showed lower levels of NAA and GABA under active tDCS compared to the sham condition, while no significant changes were observed in males. E-field modeling showed no significant differences in field magnitudes between sexes, and the magnitude of the e-fields did not correlate with changes in Glx levels between active and sham stimulation during the second interval or post-stimulation. This study demonstrates that a single session of prefrontal tDCS significantly elevates Glx levels in the left DLPFC, with effects persisting post-stimulation. However, the observed sex differences in the neurochemical response to tDCS were not linked to specific stimulation intervals or variations in e-field magnitudes, highlighting the complexity of tDCS effects and the need for personalized neuromodulation strategies.

COVID-19 Pandemic, Poverty and Health Outcomes in South Africa: Do Social Protection Programmes Protect?

Abstract The COVID-19 pandemic resulted in significant income loss for many people and deepened poverty for individuals and vulnerable populations who were adversely affected through job losses. In South Africa, income loss made it harder to acquire health care and a healthy food, which had a negative impact on health outcomes. This study hypothesised that the COVID-19 shocks disproportionately affects the poor's health, hence the need to know the impact of social protection programmes and interventions through the South Africa Social Security Grant (SASSG). Herewith, we employed the nationally represented, robust and reliable National Income Dynamics Study (NIDS) data set which was conducted in 2017 (pre-COVID-19), with the first wave of the NIDS-Coronavirus Rapid Mobile Survey (NIDS-CRAM) conducted in 2021 (during COVID-19). The household's per capita total income was used to generate poverty lines, while concentration curves and indices were employed to explain the income-health inequalities. The difference-in-difference with fixed effects model was used to estimate the impact of SASSG on the COVID-19 poverty stressors and self-reported health status. Given the significance and magnitude of institutional variables in determining the socio-economic inequalities in poor health, addressing hunger, income inequality and unemployment slightly helped to mitigate income-health inequalities during the COVID-19 shocks. We found that the social protection intervention in South Africa (SASSG) cushioned the impact of the COVID-19 pandemic in the context of poverty stressors and self-reported health status. Therefore, we advocate for programmes in South Africa that focus on reducing poverty and health disparities connected to income, as well as more proactive social protection programmes.

Regional Biomes outperform broader spatial units in capturing biodiversity responses to land‐use change

Biogeographic context, such as biome type, has a critical influence on ecological resilience, as climatic and environmental conditions impact how communities respond to anthropogenic threats. For example, land‐use change causes a greater loss of biodiversity in tropical biomes compared to temperate biomes. Furthermore, the nature of threats impacting ecosystems varies geographically. Therefore, monitoring the state of biodiversity at a high spatial resolution is crucial to capture variation in threat–responses caused by biogeographical context. However such fine‐scale ecological data collection could be prohibitively resource intensive. In this study, we aim to find the spatial scale that could best capture variation in community‐level threat responses whilst keeping data collection requirements feasible. Using a database of biodiversity records with extensive global coverage, we modelled species richness and total abundance (the responses) across land‐use types (reflecting threats), considering three different spatial scales: biomes, biogeographical realms, and regional biomes (the interaction between realm and biome). We then modelled data from three highly sampled biomes to ask how responses to threat differ between regional biomes and taxonomic group. We found strong support for regional biomes in explaining variation in species richness and total abundance compared to biomes or realms alone. Our biome case studies demonstrate that there is variation in magnitude and direction of threat responses across both regional biomes and taxonomic group, although the interpretation is limited by sampling bias in the literature. All groups in tropical forest showed a consistently negative response, whilst many taxon‐regional biome groups showed no clear response to threat in temperate forest and tropical grassland. Our results provide the first empirical evidence that the taxon‐regional biome unit has potential as a reasonable spatial unit for monitoring how ecological communities respond to threats and designing effective conservation interventions to bend the curve on biodiversity loss.

Chasing net zero: critical uncertainties in coffee emissions calculations

Summary Net zero as a policy for reducing atmospheric carbon emissions is relatively straightforward; however, the implementation of that policy is not, particularly in difficult-to-measure sectors such as agriculture. As strategies to reduce emissions are explored, multiple uncertainties in measuring these emissions are confronted. In this paper, we use the example of a coffee supply chain in Peru to illustrate the magnitude of potential variability in emissions accounting results, which represent a necessary first step in moving towards net zero. We show that scope boundaries and emissions factors chosen for carbon calculations significantly alter emissions outcomes and can result in discrepancies of over 77 million kg CO2e when scaled to a medium-size coffee trader. Net zero targets and efforts to reduce emissions may be over- or understated depending on subjective decisions that cause significant differences in emissions results. Although framework guidance exists, it is apparent that a greater set of micro-level agreements is needed for calculating the emissions of lesser-studied sectors, such as agricultural supply chains. This process is imperative to focus efforts on reducing emissions and on moving from net zero as a mere policy to action and implementation.

Investigating the Relative Contribution from Tropical Indo-Pacific SST to Asian Monsoon Precipitation Variability Using LIM

Abstract A critical issue is determining the factors that control the year-to-year variability in precipitation over southern Asia. In this study, we employ a cyclostationary linear inverse model (CS-LIM) to quantify the relative contribution of tropical Pacific and Indian Ocean sea surface temperature anomalies (SSTAs) to the interannual variability of the Asian monsoon, especially Indian summer monsoon rainfall (ISMR). Through a series of CS-LIM experiments, we isolate the impacts of the direct forcing from Pacific SSTAs, Indian Ocean SSTAs, and their interaction on Asian monsoon rainfall variability. Our results reveal distinct patterns of influence with the direct forcing from the Pacific (Indian) Ocean tending to enhance (reduce) the magnitude of precipitation variability, while the Indo-Pacific interaction acts to strongly damp the variability of Asian monsoon precipitation, especially over India. We further investigate these specific impacts on ISMR by analyzing the relationship between tropical Indo-Pacific SSTAs and the leading three empirical orthogonal functions (EOFs) of ISMR. The results from our CS-LIM experiments indicate that the direct forcing from El Niño–Southern Oscillation (ENSO) enhances the variability of the first and third EOFs, while the Indian Ocean SSTA opposes ENSO’s effects, which is consistent with previous studies. Our new results show that the tropical Indo-Pacific interaction strongly damps ISMR variability, which is due to the ENSO-induced Indian Ocean dipole (IOD) opposing the direct impacts from ENSO on ISMR. Additionally, reduced ENSO amplitude and duration associated with the Indo-Pacific interaction may also contribute to the damping effect on ISMR, but this requires further study to understand the relevant mechanisms.

The AH Pictoris Syndrome: Continuous Trains of Stunted Outbursts in Novalike Variables

Novalike variables are a subgroup of cataclysmic variables (CVs) that—unlike dwarf novae—do not exhibit strong brightenings in their long-term light curves. Variations over timescales of weeks, months, or years are mostly restricted to irregular low-amplitude modulations. However, some of them occasionally suffer from so-called stunted outbursts, that is, small-scale brightenings of less than a magnitude lasting for a couple of days to weeks. There is no consensus about the physical mechanisms behind these outbursts. Here I discuss the common properties of a group of novalike variables (which I call AH Pictoris (AH Pic) stars after its most prominent member) that exhibit a continuous train of successive stunted outbursts over their entire observational history, or at least for several years. The outburst amplitudes are stable in a given system, always ranging between 0.5 and 1 mag in the visual band. The outburst intervals, at an overall range between 12 and 30 days, and the outburst profiles can gradually evolve, but no sudden changes are observed. On shorter timescales the orbital waveforms are not only surprisingly similar, but also evolve in the same way over the outburst cycle. All AH Pic stars have absolute visual magnitudes in the overlap region between the absolute magnitudes of all novalike variables and of quiescent dwarf novae above the CV period gap. So far, I identified seven novalike variables with the consistent photometric behavior that may be termed the AH Pic syndrome. Several more systems may be related objects. The relationship of the AH Pic stars to the anomalous Z Cam stars is discussed.

Impacting Atmospheres: How Late-stage Pollution Alters Exoplanet Composition

The atmospheric composition of exoplanets is often considered as a probe of the planet’s formation conditions. How exactly the initial chemical memory may be altered from the birth to the final state of the planet, however, remains unknown. Here, we develop a simple model of pollution of planetary atmosphere by the vaporization of infalling planetesimals of varying sizes and composition (SiO2 inside 1 au and H2O outside 1 au), following their trajectory and thermal evolution through the upper advective and radiative layers of a sub-Neptune-class planet during the late stage of disk evolution. We vary the rate of pollution by changing the solid content of the disk and by dialing the level of disk gas depletion, which in turn determines the rate of planetary migration. We find that pollution by silicate grains will always be limited by the saturation limit set by the thermal state of the atmosphere. By contrast, pollution by water ice can lead to ∼2–4 orders of magnitude variation in the atmospheric water mass fraction depending on the solid and gas content of the disk. Both cases suggest that post-formation pollution can erase the initial compositional memory of formation. Post-formation pollution can potentially transform sub-Neptunes with H/He-dominated envelopes that initially formed beyond the ice line to water worlds (i.e., with a water-enriched envelope) when the disk gas is depleted by ≳2 orders of magnitude, allowing gentle migration. We additionally discuss the expected C/O ratio profile under pollution by water and refractory carbon species.

End-effector contact force estimation for the industrial robot in automated fiber placement processes with dynamic end-load variations

Contact force estimation makes the interaction between the robot and the environment perceptible and controllable without the need for additional sensor devices. For robots used in Automated Fiber Placement (AFP), contact force estimation is primarily aimed at grasping the magnitude and real-time variations of the compaction roller force, which is one of the most critical process parameters in AFP, directly related to layup accuracy and quality. However, contact force estimation during AFP faces challenges: the consumable carbon fiber prepreg material is mounted on the end-effector, leading to continuous changes in load dynamics parameters. Ignoring this situation renders contact force estimation unreliable, making real-time end-load calibration necessary. This paper first establishes a linear dynamic model of the robot and obtains the Variable Parameter Set (VPS) related to end-load. Then, combining distance sensors and weighted moving average, the volume changes in material rollers are measured to perform fast load calibration of the end-effector and update the VPS. Subsequently, a joint hybrid friction model is established and calibrated. Based on this, a Disturbance Kalman Filter (DKF) observer is established using inverse dynamics and discrete Kalman filter algorithms for real-time estimation of contact force. The calibration routine of the DKF observer considers the noise in measured motor currents and errors in velocity data from individual joints. Vertical lifting experiments and actual AFP experiments demonstrate that fast load calibration and DKF observer can provide robust and accurate estimation of end-effector contact force. Compared to force sensors and the DKF observer without FLC, the RMSE is reduced by over 49 %.

Land surface temperature trends derived from Landsat imagery in the Swiss Alps

Abstract. The warming of high mountain regions caused by climate change is leading to glacier retreat, decreasing snow cover, and thawing permafrost, all of which have far-reaching effects on ecosystems and societies. Landsat Collection 2 provides multi-decadal land surface temperature (LST) data, principally suited for large-scale monitoring at high spatial resolution. In this study, we assess the potential to extract LST trends using Landsat 5, 7, and 8 time series. We conduct a comprehensive comparison of both LST and LST trends with data from 119 ground stations of the Intercantonal Measurement and Information System (IMIS) network, located at high elevations in the Swiss Alps. The direct comparison of Landsat and IMIS LST yields robust satellite data with a mean accuracy and precision of 0.26 and 4.68 K, respectively. For LST trends derived from a 22.6-year record length, as imposed by the IMIS data, we obtain a mean accuracy and precision of −0.02 and 0.13 K yr−1, respectively. However, we find that Landsat LST trends are biased due to unstable diurnal acquisition times, especially for Landsat 5 and 7. Consequently, LST trend maps derived from 38.5-year Landsat data exhibit systematic variations with topographic slope and aspect that we attribute to changes in direct shortwave radiation between different acquisition times. We discuss the origin of the magnitude and spatial variation of the LST trend bias in comparison with modeled changes in direct shortwave radiation and propose a simple approach to estimate the LST trend bias. After correcting for the LST trend bias, the remaining LST trend values average between 0.07 and 0.10 K yr−1. Furthermore, the comparison of Landsat- and IMIS-derived LST trends suggests the existence of a clear-sky bias, with an average value of 0.027 K yr−1. Despite these challenges, we conclude that Landsat LST data offer valuable high-resolution records of spatial and temporal LST variations in mountainous terrain. In particular, changes in the mountain cryosphere, such as glacier retreat, glacier debris cover evolution, and changes in snow cover, are preserved in the LST trends and potentially contribute to improved prediction of permafrost temperatures with large spatial coverage. Our study highlights the significance of understanding and addressing biases in LST trends for reliable monitoring in such challenging terrains.

Climatic oscillation based 3-dimensional drought risk assessment over India

Drought risk assessment is essential for the efficient design of water resource infrastructures and agricultural planning. Conventional drought studies define droughts either in a spatial or temporal framework without considering the simultaneous temporal and spatial progression of droughts. Spatiotemporal drought (SPD), a dynamic and complex phenomenon, has been relatively understudied due to the challenges in developing algorithms for their identification. In this study, we use a 3-dimensional drought identification framework to identify the SPD events across India. Further, as large-scale ocean-atmospheric phenomena namely El Niño Southern Oscillation (ENSO) and Equatorial Indian Ocean Oscillation (EQUINOO) play an important role in modulating the occurrence of droughts in India, we investigated the influence of these climatic oscillations on SPD characteristics across different climatic regions of India. Further, ENSO-based drought risk assessment using drought characteristics and the synergy between univariate and multivariate drought risks are also evaluated. Results show that 1) there are significant seasonal and spatial variations in occurrences and magnitude of SPD characteristics for the different climate phases. SPDs during the ENSO positive (El Niño) and the EQUINOO negative phases have higher severity, especially over the monsoon core region. In northwest India, the median drought severity during El Niño events is over three times higher than La Niña events. Across most of India, a major portion of SPD event onset occurs during the monsoon seasons, however in the north-western and south-eastern regions an equal portion of drought onset occurs during the pre-monsoon and post-monsoon season, respectively. 2) Further, the ENSO-based drought risk assessment reveals that severe and longer-duration SPD events are associated with El Niño phases, making ENSO a crucial factor in drought frequency analysis. 3) The synergy between the univariate and multivariate drought risks conditioned on ENSO reveal that overall drought risks are linked to the magnitude of individual drought characteristics which have a strong association with ENSO phases. Thus, design criteria for drought resilient infrastructure should be based on the dominant drought characteristics influenced by ENSO phases for effective drought risk assessment. Overall, the study underscores the significant impact of ENSO on SPDs in India and the importance of incorporating ENSO information in drought frequency analysis for reliable risk assessments.