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Background and Aim: Social isolation stress (SIS) and individual housing have been shown to cause abnormal cognitive insufficiencies, altered anxiety levels, and signs of psychiatric diseases. Acorus calamus (AC), commonly known as Sweet Flag, has been widely used in India to treat neurological, metabolic, and respiratory disorders, indicating its potential therapeutic value. This study aimed to determine the antidepressant and antioxidative effects of AC on rats subjected to long-term, social isolation-induced stress. Materials and Methods: This study involved 2-month-old male rats (24) weighing approximately 180–200 g bred in-house. The rats were divided into four groups (n = 6): Group 1 received saline, Group 2 received SIS, Group 3 received only 50 mg/kg AC, and Group 4 received 50 mg/kg AC and SIS for 6 weeks. After this, behavioral, biochemical, and neuronal assays were conducted. Results: Behavioral experiments showed significantly higher activity levels (p < 0.001) in AC-treated rats than in the SIS group. In addition, rats subjected to SIS with AC treatment exhibited enhanced total antioxidants, superoxide dismutase, and neuronal assays compared to rats subjected to SIS alone. Conclusion: Acorus calamus treatment improved the antidepressant and antioxidant potential against SIS in rat brain tissue. Moreover, we proved that AC can effectively reverse the neurotoxicity induced by SIS in animal models. As we battle against the coronavirus disease 2019 pandemic and social isolation, AC could be considered a supplementary treatment to alleviate depressive-like symptoms in our present-day lifestyle. [ABSTRACT FROM AUTHOR]

Background: The length of hospitalization is prolonged in patients with acute pancreatitis due to delay in feeding. The present study aimed at evaluating hunger-based early feeding for its efficacy in reducing length of hospitalisation. Aims and Methods: This was a parallel arm superiority randomized control trial. Patients with moderate and severe acute pancreatitis were randomised into hunger-based feeding and conventional feeding groups. Patients in hunger-based feeding group commenced feeding once they felt hungry and in conventional feeding group after normalization of biochemical parameters and resolution of symptoms. Patients were followed up till their discharge and were analyzed for length of hospitalisation, fasting duration, feed intolerance, incidence of infective morbidities and invasive procedures. Results: Hunger-based feeding and conventional feeding group included 56 and 54 patients, respectively. Hunger-based feeding led to a decrease in length of hospitalization (6.3 days in hunger-based feeding vs 7.3 days in conventional feeding group, P = 0.041) and fasting duration (1.6 days in hunger-based feeding vs 2.7 days in conventional feeding group, P = 0.001).The incidence of feed intolerance (P = 0.098), infective morbidities and invasive non-surgical procedures were similar in both the groups. Conclusion: Hunger-based feeding significantly reduces length of hospitalization and fasting duration in cases of moderate and severe acute pancreatitis without any significant rise in the incidence of complications. Registration number of Clinical Trails Registry India CTRI/2019/01/017,144. [ABSTRACT FROM AUTHOR]

Zebrafish have gained momentum as a leading experimental model in recent years. At present, the zebrafish vertebrate model is increasingly used due to its multifactorial similarities to humans that include genetic, organ, and cellular factors. With the emergence of novel research techniques that are very expensive, it is necessary to develop affordable and valid experimental models. This review aimed to highlight some of the most important similarities between zebrafish and humans by emphasizing the relevance of the first in simulating neurological disorders and craniofacial deformity. [ABSTRACT FROM AUTHOR]

Introduction: morphology of clavicle is essential in understanding and designing fixative devices for displaced fractures of clavicle as well as for radiologists and physicians as variations in costoclavicular ligament bears resemblance with some pathological conditions. The aim of this study was to observe the clavicular morphology in relation to rhomboid impression and to examine the cross sectional profile at various points on the clavicle. Material and Methods: the present study utilized 80 human dried adult clavicles and the patterns of costo-clavicular ligament attachment were studied. The topographical distance between the medial ends of clavicle and attachment of costo-clavicular ligament was determined. The cross sectional morphology of clavicle was studied at the shaft, medial and lateral ends. Results: the cross sectional morphology showed a transition from quadrilateral shape on medial side to transversely flat on lateral side. The average topographical distance between the medial most part of clavicle and the costo-clavicular ligament was 8.33 mm. The most frequent pattern of rhomboid impression was rough and elevated, which is observed in 28.75% of cases. Conclusion: the data collected from the present study will help the medical fraternity in reporting of fractures and to plan for adequate fixative devices. [ABSTRACT FROM AUTHOR]

Introduction: we report a case of tortuous external iliac artery (EIA), which was compressing the obturator nerve. This was observed over the left side in an embalmed male cadaver, of approximately 70-year age individual. The EIA was mimicking a siphon and this siphon was compressing the structures entering the obturator canal, particularly the obturator nerve. It was observed that the EIA was thicker and harder than the usual. The observation of EIA of the right side did not reveal any tortuosity. The tortuous EIA compressing the obturator nerve as in this case may cause symptoms like pain and tingling sensation, numbness in the hip and knee joints. In addition, this may lead to adductor muscles weakness. Such neurovascular compression as seen in this present case are noteworthy especially with procedures concerned with the obturator nerve block. The knowledge of tortuous EIA is enlightening to the cardiologist during the procedures like catheterization and implanting the endografts. [ABSTRACT FROM AUTHOR]

Introduction: Aluminum (Al) is a known neurotoxic which is found in air, food and utensils, medicinal preparations, etc., Ficus religiosa (FR) is known as the peepal tree which is worshipped by people at large and has many medicinal importance. The objective of the study is to compare the Al groups of different durations and the treatment groups with FR leaf extract in male Wistar rats. Materials and Methods: In this study, we have taken seven groups of male albino Wistar rats, six in each. Group 1 was normal control group. Groups 2 and 3 were induced groups and Groups 4-7 are treated groups. On the last day of treatment, the brain of the animals was removed, and histology slides were prepared, and viable neurons were counted using software. For behavioral analysis, the passive avoidance test was carried out. Here, the treated Groups 4 and 5 are the groups in which the leaf extract of FR was given after treating with Al for 25 days and for Groups 6 and 7, given after treating with Al for 45 days. The comparison of different durations of the Al groups and treated groups was carried out based on neuronal count in CA3 region of hippocampus. Results: We have observed the neurodegeneration in all regions of hippocampus including dentate gyrus, but mainly, the neurodegeneration was observed in CA3 region of hippocampus. In both the parameters, there was no significant difference observed in terms of change of duration of Al (P > 0.05). The neurodegeneration observed in both Al groups was the same. The effect of treatment was observed a similar improvement in all treated groups even after in change in duration of Al (P > 0.05). Conclusion: Aluminium induced neurodegeneration in rat's brain in both higher and lower duration and in both cases Ficus religiosa treated effectively against neurotoxicity of Al. [ABSTRACT FROM AUTHOR]

A high-fidelity multiscale modeling framework that integrates information from atomistic simulations pertaining to polymer chain sliding and bond dissociation is utilized to study damage evolution and failure in carbon nanotube (CNT)-reinforced nanocomposites. The nanocomposite constituents (microfiber, polymer, and CNTs) are explicitly modeled at the microscale using representative unit cells (RUCs). The modeled constituents are subsequently employed in a multiscale framework to describe damage initiation and propagation in these systems under transverse loading. Two CNT architectures, randomly dispersed and radially grown, are investigated. Damage initiation sites and damage evolution trends are studied, with results indicating that the presence of CNTs causes a unique stress state at the sub-microscale. This can lead to accelerated damage progression, which can be mitigated by architectural reconfiguration of the CNTs. Additionally, the Schapery potential theory is extended to develop an orthotropic nonlinear damage model that captures global behavior of the nanocomposite RUCs in a computationally efficient manner, and can be utilized as a numerical surrogate for structural scale nanocomposite analysis. [ABSTRACT FROM AUTHOR]

This paper examines microscale and sub-microscale damage mechanisms in carbon nanotube (CNT) reinforced nanocomposites. A multiscale modeling framework with a damage model developed from molecular dynamics simulation, is employed to study the physical mechanisms of damage initiation and propagation in CNT nanocomposites at the sub-microscale. Two CNT arrangements, randomly dispersed and entangled agglomerates, are examined. This investigation offers insights into damage properties of particular configurations of CNTs in a polymer matrix, in addition to specific understanding related to damage concentration effects around the filler material at the sub-microscale. High spatial CNT concentration differential is observed to affect damage initiation and rate of damage. It is further shown to result in sub-microscale crack initiation at low global strains, a phenomenon that is also observed at agglomeration boundaries, which results in CNT agglomerations to behave as crack initiation sites. [ABSTRACT FROM AUTHOR]

The carbon fiber/polymer matrix interphase region plays an important role in failure initiation and accurate modeling techniques are integral to study the effects of this complex region on the composite response. In composites infused with nanoparticles such as carbon nanotubes (CNT), the interphase region is more complex due to the presence of multiple constituents and their interactions with each other. An atomistic methodology to simulate the constituent interphases in carbon fiber reinforced CNT/epoxy nanocomposites is presented in this paper. The interphase model consisting of voids in multiple graphene layers enable the simulation of physical entanglement between the polymer matrix and the irregular carbon fiber surface. The voids in graphene layers are generated by removing carbon atoms and hydrogenating the end carbon atoms, which better represent the roughness of the carbon fiber surface. The epoxy curing studies and the response of fiber/matrix interphase under mechanical loading are investigated through molecular dynamic (MD) simulations with appropriate classical/harmonic and bond order-based force fields. Furthermore, the atomistic force-displacement behavior is also extracted to formulate a traction-separation law for interface cohesive zone models. The cohesive behavior determined from molecular models is parameterized in equations that can be integrated with an atomistically informed multiscale modeling framework. [ABSTRACT FROM AUTHOR]

A multiscale-modeling framework is presented to understand damage and failure response in carbon nanotube reinforced nanocomposites. A damage model is developed using the framework of continuum damage mechanics with a physical damage evolution equation inspired by molecular dynamics simulations. This damage formulation is applied to randomly dispersed carbon nanotube reinforced nanocomposite unit cells with periodic boundary conditions to investigate preferred sites and the tendency towards damage. The continuum model is seen as successfully capturing much of the unique nonlinear trends observed in the molecular dynamics simulations in a volume 1000 times greater than the molecular dynamics unit cell. Additionally, application of the damage model to the continuum unit cell revealed insights into the failure of carbon nanotube reinforced nanocomposites at the sub-microscale. [ABSTRACT FROM AUTHOR]

A comprehensive, point-information-to-continuum-level analysis framework is presented in this paper to accurately characterize the behavior of carbon nanotube (CNT)-enhanced composite materials. Molecular dynamics (MD) simulations are performed to study sub-nanoscale interactions of the CNT with the polymeric phase of the nanocomposite. The effect of cross-linking between the epoxy resin and the hardener on the mechanical properties of the polymer is investigated; furthermore, the effect of CNT weight fraction on the probability distribution of polymer cross-linking degree is also studied through stochastic models. The stochastic distributions obtained from MD simulations provide a basis to simulate local variations in the matrix properties in the continuum model at the microscale. The inclusion of an atomistically informed elastic–plastic model at the microscale reveals a significant deviation of the mechanical properties from those obtained based on classical homogenization approaches. Microstructural variability arising from heterogeneous cross-linking degree in the polymer phase and variations in fiber geometry and spacing is also found to cause deviations in the mechanical response when compared to the assumption of a perfectly ordered fiber–matrix microstructure. [ABSTRACT FROM AUTHOR]

Introduction: aluminium is a nonferrous metal which is consumed daily by people knowingly or unknowingly from various sources like the air, food, drinking water and medicines. The debate on the issue that aluminium (Al) could be a contributing factor for some neurological diseases have intrigued several researchers to focus their study on effect of Al on the nervous system. The neurotoxicity of Al is well reported but the optimal neurotoxic dose of it is still not clear. This review article compiles different dosages of Aluminium choride (AlCl3) that has induced neurotoxicity in experimental rat models, as AlCl3 is predominanty used in antiperspirants, medicines and cosmetic materials. It is mainly focused upon two routes of administration of AlCl3 i.e oral & intra-peritoneal. The neurotoxic effect of Al leading to various disorders like Alzheimer's disease, dementia and toxic effect in cerebellum, were observed by various authors in experimental rats. We have tabulated different dosages of AlCl3 that has induced neurotoxicity and is effect on different parameters which would be helpful for researchers in conducting experiments in this area. The lethal dose of aluminium chloride (LD 50) is reported as 3630±400mg/kg/body weight by oral route in rats. From numerous studies on rats it is evident that the highest dose of Al given to rats was 1900mg/kgbw by oral route and 150mg/kgbw by intra-peritoneal route. [ABSTRACT FROM AUTHOR]

Disturbance in the organogenesis of tongue might lead to some malformations like tongue tie, bifid tongue and hairy tongue. Severe degrees of these anomalies may cause speech impairment or periodontal defects. The present study was done on patients of the southern coastal belt of India during the past two years, on gross tongue anomalies. The results of the present study reveal that occurrence of tongue tie is 0.2% and bifid tongue is 0.3% in the southern coastal population. Since great majority of these oral anomalies have genetic basis the purpose of the present report is to highlight that these anomalies can exist without any familial background and also to suggest that environmental factor may play a role in the etiogenesis of these anomalies. [ABSTRACT FROM AUTHOR]

This work presents a multiscale damage model that accounts for ceramic matrix composite (CMC) length scale dependent behavior, including scale-specific brittle matrix damage initiation and propagation. Internal state variable theory is implemented to obtain the stress–strain constitutive relationship for damaged ceramic matrix material using damage variables which capture the effects of matrix cracking and nucleation and growth of matrix porosity. Matrix cracking is modeled using a damage variable determined using fracture mechanics and the self-consistent scheme. This methodology provides an effective way to model the effects of matrix cracks which initiate when stress intensity factors exceed the fracture toughness of the material, and whose growth is governed by crack growth kinetics. An additional source of material nonlinearity, matrix porosity, occurs as a result of material diffusion around grain boundaries and is related to the material entropy dissipation. These effects are captured using a porosity state variable that is explicitly related to the volumetric strain. The nonlinear predictive capabilities of the material model are demonstrated for monolithic silicon carbide, unidirectional (UD) carbon fiber/silicon carbide matrix (C/SiC) CMC, and five-harness satin (5HS) woven C/SiC CMC. The model predictions are in excellent agreement with experimental observations for 2D woven C/SiC CMCs from literature. [ABSTRACT FROM AUTHOR]

• Scheduled commercial flight monitoring is challenging due to complex flight dataset. • Logarithmic multivariate Gaussian model fuses information from on-board sensors. • Unimodal hypothesis handles time-series information without need of re-sampling. • Mini-batch Gaussian learning eliminates the restriction on data size. • Mechanical and operational anomalies in an airline flight dataset are analyzed. This paper presents a machine learning approach to evaluate the performance of aircrafts using on-board sensor information on commercially scheduled flights with the aim to further improve system health monitoring strategies in air transportation. Logarithmic multivariate Gaussian models are trained to evaluate the performance of aircrafts at different flight phases (takeoff, ascent, cruise, etc.) separately. By including a forward synchronization, feature selection, and mini-batch training process, this model overcomes challenges introduced by the large size and high dimensionality of flight datasets. This framework also addresses the re-sampling issue in existing literature causing difficulties in handling time-series signals with different lengths. For demonstration and validation, the developed model is applied to analyze performance anomalies associated with the mechanical system and pilot operation in a historical flight dataset. Compared with existing literature focusing on similar datasets, this evaluation methodology shows promise in detecting performance anomalies especially at approach and takeoff phases. Therefore, the developed model is expected to be an effective addition to the current anomaly analysis and monitoring technologies for scheduled commercial flights. Applications include assisting transportation management systems by handling large amounts of historical flight datasets to analyze mechanical and operational anomalies, which may potentially improve future aeronautical system design and pilot training. [ABSTRACT FROM AUTHOR]

Abstract An atomistically-informed multiscale modeling framework to investigate damage evolution and failure in radially-grown carbon nanotube (CNT) architecture is detailed in this paper. Molecular dynamics (MD) simulations are performed to investigate the effects of nano-reinforcements on the elastic-plastic characteristics of the constituent interphase in the radially-grown nanocomposite. An interphase damage model is developed using the continuum damage mechanics approach with damage evolution equations derived using atomistic simulations. The developed damage model is integrated with a high-fidelity micromechanical analysis and captures the underlying physical behavior that could be attributed to the enhancement of the out-of-plane properties at higher length scales. The mechanical properties of the nanocomposite obtained from micromechanical simulations are compared to experimental values reported in the literature, to validate the developed modeling framework. Conclusions are presented by comparing the material response of radially-grown CNT architectures with the traditional fiber reinforced polymer (FRP) with dispersed CNT architecture. Graphical abstract Image [ABSTRACT FROM AUTHOR]

A methodology that accurately simulates the brittle behavior of epoxy polymers initiating at the molecular level due to bond elongation and subsequent bond dissociation is presented in this paper. The system investigated in this study comprises a combination of crystalline carbon nanotubes (CNTs) dispersed in epoxy polymer molecules. Molecular dynamics (MD) simulations are performed with an appropriate bond order-based force field to capture deformation-induced bond dissociation between atoms within the simulation volume. During deformation, the thermal vibration of molecules causes the elongated bonds to re-equilibrate; thus, the effect of mechanical deformation on bond elongation and scission cannot be captured effectively. This issue is overcome by deforming the simulation volume at zero temperature-a technique adopted from the concept of quasi-continuum and demonstrated successfully in the authors' previous work. Results showed that a combination of MD deformation tests with ultra-high strain rates at near-zero temperatures provides a computationally efficient alternative for the study of bond dissociation phenomenon in amorphous epoxy polymer. In this paper, the ultra-high strain rate deformation approach is extended to the CNT-epoxy system at various CNT weight fractions and the corresponding bond disassociation energy extracted from the simulation volume is used as input to a low-fidelity continuum damage mechanics (CDM) model to demonstrate the bridging of length scales and to study matrix failure at the microscale. The material parameters for the classical CDM model are directly obtained from physics-based atomistic simulations, thus improving the accuracy of the multiscale approach. [ABSTRACT FROM AUTHOR]

• Real-time, and data-driven health monitoring method using support vector regression. • Feature subset selection performed with correlation-based method. • Predict possible flight performance anomalies prior to actual anomalous event. • Proposed method validated with recorded flight data and simulated anomalous scenario. The development of an automated health monitoring framework is critical for aviation system safety, especially considering the expected increase in air traffic over the next decade. Conventional approaches such as model-based and exceedance methods have a low detection accuracy and are limited to specific applications. This paper proposes a robust real-time health monitoring framework for detecting performance anomalies, which may impact system safety during flight operations, with high accuracy and generalized applicability. The proposed monitoring framework utilizes sensor data from commercial flight data recorders to predict possible flight performance anomalies. Decimation, a signal processing technique, in conjunction with Savitzky-Golay filtering is utilized to preprocess the dataset and mitigate sampling rate and noise issues that prevent direct usage of historical flight data. Correlation-based feature subset selection is subsequently performed, and these features are used to train a support vector machine that predicts flight performance. With this model, performance anomalies in the test data are automatically detected based on deviations from the predicted flight behavior. The proposed monitoring framework was demonstrated to detect performance anomalies in real-time and exhibited accurate detection capabilities with high computational efficiency. [ABSTRACT FROM AUTHOR]

Abstract As projected by climate change models, increase in sea surface temperature and precipitation in the future may alter nutrient cycling in the coastal regions due to potential changes in phytoplankton community structure and their ability to assimilate nitrogen (N) and carbon (C). An experiment simulating different temperature and salinity conditions (28°C-35 ambient conditions, 28ºC-31, 31ºC-35 and 31ºC-31) in mesocosms containing 1000 L of coastal water from the Arabian Sea was performed and N uptake rates were measured using 15N tracer technique on 2nd, 5th, 7th and 10th day of the experiment. The results show that, under all conditions, the total N (NO 3 − + NH 4 +) uptake rates were lower in the beginning and on the final day of the tracer experiment, while it peaked during middle, consistent with chlorophyll a concentrations. Total N uptake rate was significantly lower (p = 0.003) under ambient temperature-lower salinity condition (28ºC-31) than the others. This indicates that lowering of salinity in coastal regions due to excessive rainfall in the future may affect the N uptake potential of the phytoplankton, which may change the regional C and N budget. Highlights • First large scale mesocosm experiment to study response of bacterioplankton community from the coastal Arabian Sea. • Results suggest significant decline in nitrogen uptake potential of phytoplankton due to reduction in salinity. • Excessive rainfall in future may affect the N uptake potential of the coastal phytoplankton. [ABSTRACT FROM AUTHOR]

The south west coast of India has been showing a steady increase in shellfish cultivation both for local consumption and fishery export, over recent years. Perna viridis and Crassostrea madrasensis are two species of bivalve molluscs which grow in some selected regions of southern Karnataka, close to the city of Mangalore. In the early 1980s, shellfish consumers in the region were affected by intoxication from Paralytic Shellfish Poison present in local bivalves (clams and oysters) resulting in hospitalisation of many, including one fatality. Since then, there have been no further reports of serious shellfish intoxication and there is little awareness of the risks from natural toxins and no routine monitoring programme in place to protect shellfish consumers. This study presents the findings from the first ever systematic assessment of the presence of marine toxins in mussels and oysters grown in four different shellfish harvesting areas in the region. Shellfish were collected and subjected to analysis for ASP, PSP and lipophilic toxins, as well as a suite of non-EU regulated toxins such as tetrodotoxin and selected cyclic imines. Results revealed the presence of low levels of PSP toxins in oysters throughout the study period. Overall, total toxicities reached a maximum of 10% of the EU regulatory limit of 800 μg STX eq/kg. Toxin profiles were similar to those reported from the 1980 outbreak. No evidence was found for significant levels of ASP and lipophilic toxins, although some cyclic imines were detected, including gymnodimine. The results indicated that the risk to shellfish consumers during this specific study period would have been low. However, with historical evidence for extremely high levels of PSP toxins in molluscs, there is a strong need for routine surveillance of shellfish production areas for marine toxins, in order to mitigate against human health impacts resulting from unexpected harmful algal blooms, with potentially devastating socio-economic consequences. [ABSTRACT FROM AUTHOR]

Measuring the strengths of asteroidal materials is important for developing mitigation strategies for potential Earth impactors and for understanding properties of in situ materials on asteroids during human and robotic exploration. Studies of asteroid disruption and fragmentation have typically used the strengths determined from terrestrial analog materials, although questions have been raised regarding the suitability of these materials. The few published measurements of meteorite strength are typically significantly greater than those estimated from the stratospheric breakup of meter-sized meteoroids. Given the paucity of relevant strength data, the scale-varying strength properties of meteoritic and asteroidal materials are poorly constrained. Based on our uniaxial failure studies of centimeter-sized cubes of a carbonaceous and ordinary chondrite, we develop the first Weibull failure distribution analysis of meteorites. This Weibull distribution projected to meter scales, overlaps the strengths determined from asteroidal airbursts and can be used to predict properties of to the 100 m scale. In addition, our analysis shows that meter-scale boulders on asteroids are significantly weaker than small pieces of meteorites, while large meteorites surviving on Earth are selected by attrition. Further, the common use of terrestrial analog materials to predict scale-dependent strength properties significantly overestimates the strength of meter-sized asteroidal materials and therefore is unlikely well suited for the modeling of asteroid disruption and fragmentation. Given the strength scale-dependence determined for carbonaceous and ordinary chondrite meteorites, our results suggest that boulders of similar composition on asteroids will have compressive strengths significantly less than typical terrestrial rocks. [ABSTRACT FROM AUTHOR]

Based on 21 years of phytoplankton and environmental monitoring data from the surface water of coastal southeast Arabian Sea, we demonstrate a shift in phytoplankton community towards higher sample genus richness and diatom abundance during the two decades of observations. Analyses were based on 587 water samples collected between 1990 and 2010 and additionally revealed marked long-term changes in sea surface temperature (SST), sea surface salinity (SSS) and turbidity (Secchi depth). The abundances of dinoflagellate genera were positively correlated to SST, particularly during and after the 1997–1998 El Niño Southern Oscillation event. Several diatom genera increased in abundances with decreasing turbidity around and after 1995–2000, mainly the large celled genera Coscinodiscus spp, Odontella spp and Ditylum spp. In 1996–2000, sample genus richness increased from mean of 8–14, and decreased to 11 thereafter. The increase in sample genus richness was linked to the more frequent presence of most taxa during 1996–2000. Increasing Secchi depth and abundance of frequently encountered large-celled diatoms concurrent with decreasing abundances of Trichodesmium spp might signal the alleviation of the nitrogen limitation in the region, favouring diatoms. [ABSTRACT FROM AUTHOR]

Purpose: Ethmoidal foramina on the medial orbital wall show a higher incidence of variation. Surgeons performing endonasal, anterior cranial fossa and medial orbital wall surgeries must be aware of these variations as they are a source of hemorrhage and also serve as landmark in proximity to the orbital apex. Aim: The present study aims to describe the morphometric distances of various ethmoidal foramina between anterior lacrimal crest to optic canal in south Indian dry human skulls. Materials and method: The study was done on 44 adult dry human skulls. The occurrence of Ethmoidal foramina was noted by direct inspection. The distance of Ethmoidal foramina from anterior lacrimal crest to optic canal was measured with the help of ruler, probe and magnifying glass. Results: The Posterior ethmoidal foramina were found in all 44 skulls bilaterally. Middle ethmoidal foramen was present in 12 and 13 skulls on right and left, respectively. Anterior ethmoidal foramen was found in 38 and 37 skulls on right and left, respectively. The distance between anterior lacrimal crest (ALC) and posterior lacrimal crest (PLC) was in the range of 3-8 mm and that of ALC to anterior ethmoidal foramen was in the range of 24-30 mm. The range of distance between anterior ethmoidal foramen to posterior ethmoidal foramen was 9-17 mm and that between posterior ethmoidal foramen to optic canal was 5-13 mm. Conclusion: These observations would help to predict the anatomical variations in the position of ethmoidal foramina with respect to anterior and posterior lacrimal crest and ensure the safe and precise performance of medial orbital wall surgeries to avoid injuries to the important neurovascular bundles passing through various foramina and fissures. [ABSTRACT FROM AUTHOR]