physical factors
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Author(s):  
Yongyang Liu ◽  
Yaxin Lu ◽  
Zhiyong Tang ◽  
Yuheng Cao ◽  
Dehua Huang ◽  
...  

Axonal transport plays a significant role in the establishment of neuronal polarity, axon growth, and synapse formation during neuronal development. The axon of a naturally growing neuron is a highly complex and multifurcated structure with a large number of bends and branches. Nowadays, the study of dynamic axonal transport in morphologically complex neurons is greatly limited by the technological barrier. Here, a sparse gene transfection strategy was developed to locate fluorescent mCherry in the lysosome of primary neurons, thus enabling us to track the lysosome-based axonal transport with a single-particle resolution. Thereby, several axonal transport models were observed, including forward or backward transport model, stop-and-go model, repeated back-and-forth transport model, and cross-branch transport model. Then, the accurate single-particle velocity quantification by TrackMate revealed a highly heterogeneous and discontinuous transportation process of lysosome-based axonal transport in freely orientated axons. And, multiple physical factors, such as the axonal structure and the size of particles, were disclosed to affect the velocity of particle transporting in freely orientated axons. The combined single-particle fluorescence tracking and TrackMate assay can be served as a facile tool for evaluating axonal transport in neuronal development and axonal transport-related diseases.


2022 ◽  
Vol 20 (2) ◽  
pp. 321-327
Author(s):  
Aniqa Naeem ◽  
Rida Batool

Purpose: To study Cr (VI) removal from waste water using chromium-resistant bacterial strains in combination with rice husk. Methods: Two strains of Exiguobacterium sp. resistant to chromium (VI) were applied in the present work. Rice husk (RH) was used as an agricultural waste for Cr (VI) removal. The elimination of Cr from the husk was chemically facilitated using hydrochloric, sulphuric and citric acids, as well as formaldehyde and potassium dihydrogen phosphate Investigation of optimum physical factors such as pH, temperature, shaking speed and biomass concentration on Cr (VI) removal was carried out using citric acid-processed rice husk alone, and in combination of bacterial strains. Fourier transform infra-red (FTIR) spectroscopy was performed to determine the contributions of different functional groups involved in Cr (VI) binding. Scanning electron microscopy (SEM) of treated and untreated RH was also performed. Results: Citric acid-processed RH was most effective in the removal of chromate (97.3 %). The two bacterial strains combined with rice husk proved highly efficient in Cr (VI) removal from sterile and non-sterile industrial effluents. FTIR spectra showed the involvement of esters, amines and aliphatic functional groups in Cr (VI) binding, while SEM displayed the damaging effects of Cr (VI) on the surface of RH; however, bacterial inoculation minimized the damage. Conclusion: Exopolysaccharides from Exiguobacterium strains and citric acid-processed rice husk demonstrated high efficiency for Cr (VI) removal. Hence, RH with these bacterial strains are potential biosorbents for control of heavy metal contamination arising from industrial effluents.


Author(s):  
Fatih Karaosmanoglu

On the ecological conditions and distribution of vegetation in any geographical area; The mutual interaction of factors such as climate (temperature-precipitation), topography (altitude-mountain extent), soil plays an important role. In addition, these factors also determine the ecological and geographical distribution of vegetation at micro and macro levels. In this study, geographic information systems (GIS) are used as a method and here; Digital elevation model of the basin (30x30), multi-year climate data (precipitation, temperature), Erinc climate type results, soil distribution, stand distribution, plant profiles and field photographs are the materials used in the study. By processing these data, the type and distribution of vegetation in the Goksu basin were determined. According to these findings, physical factors such as altitude and the extent of the mountains have created significant differences in the precipitation and temperature distribution of the basin. This difference was clearly observed in the Erinc climate classification results, and the south of the basin presented humid and semihumid climate characteristics, and the north presented semi-arid climate characteristics. These climatic conditions also affected the soil formation and type,causing a wide distribution of non-calcareous brown soils and non-calcareous brown forest soils in the field. As a result of all these conditions, plant species showed different vertical and spatial distribution. In the part from the south of the basin to Saimbeyli, plant species such maquis, pinus brutia, pinus nigra, Cedrus libani, Abies, Juniperus are distributed, while in the north, oak species such as oak, Bromus torhentallus, Astragalus, Thymus have been distributed. Thus, factors such as climate, topography and soil played an important role in the spread of vegetation and species in the Goksu Basin.


2022 ◽  
Vol 9 ◽  
Author(s):  
Sébastien M. J. Portalier ◽  
Gregor F. Fussmann ◽  
Michel Loreau ◽  
Mehdi Cherif

First derivations of the functional response were mechanistic, but subsequent uses of these functions tended to be phenomenological. Further understanding of the mechanisms underpinning predator-prey relationships might lead to novel insights into functional response in natural systems. Because recent consideration of the physical properties of the environment has improved our understanding of predator-prey interactions, we advocate the use of physics-based approaches for the derivation of the functional response from first principles. These physical factors affect the functional response by constraining the ability of both predators and prey to move according to their size. A physics-based derivation of the functional response should thus consider the movement of organisms in relation to their physical environment. One recent article presents a model along these criteria. As an initial validation of our claim, we use a slightly modified version of this model to derive the classical parameters of the functional response (i.e., attack rate and handling time) of aquatic organisms, as affected by body size, buoyancy, water density and viscosity. We compared the predictions to relevant data. Our model provided good fit for most parameters, but failed to predict handling time. Remarkably, this is the only parameter whose derivation did not rely on physical principles. Parameters in the model were not estimated from observational data. Hence, systematic discrepancies between predictions and real data point immediately to errors in the model. An added benefit to functional response derivation from physical principles is thus to provide easy ways to validate or falsify hypotheses about predator-prey relationships.


This research emphasizes the cause of landslides that occur in Hakha Town and its environ. The main aim is to investigate the distinct phenomena that result in a landslide and to provide suggestions that can reduce the risk of landslide in its prone area. Regarding the two phenomena, natural and man-made, the data on soil, steep slope, monsoon rainfall, pine forest areas, water sources, motor-car road area, population, and houses were collected by field survey, observation, and questionnaires. The collected data were processed and analyzed by using remote sensing methods, qualitative and quantitative methods, and Geographic Information System. According to the results, major causes of the landslides in the study area are found to be due to location lying between 1,830 meters (6,000 ft) and 2,440 meters (8,000 ft) above sea level and establishing of the settlements on steep slopes, receiving plenty of rainfall under the mountain climate with the extremely cold winter season, the existence of unstable and unconsolidated soil and lithology, extending construction of new roads and expansion of the existing roads, population growth and settling of more people in the urban area, and collapsing of big old pine trees. In conclusion, landslides in the study area are found resulting from combined activities of physical factors and human impacts.


2022 ◽  
Vol 12 (3) ◽  
pp. 57-66
Author(s):  
Md Al Amin ◽  
Arka Chakraborty

Workers’ performance and efficiency are dependent on their workplace facilities. The present study attempts to identify the six physical factors of the workplace environment: furniture and equipment design, air quality, temperature, sanitation, lighting and noise. Workers' feedback is evaluated by using 5 scale Likert method and it is found that found workplace temperature is most critical for workers' performance. The purpose of this study is to identify workers' impressions about their workplace environment and provide a better understanding to the managers about improvement. Industry-level emphasis on these factors can improve workers' performance standards and production quality. Previous work performance studies are not focused on hygiene and sanitation facility but due to the corona pandemic situation sanitation concern has been raised. This study aims to explore the relationship of these factors with gender and work experience of the workers. Variation in each group has provided an understanding of the basic demand of each type of worker. Journal of Engineering Science 12(3), 2021, 57-66


2022 ◽  
Vol 7 ◽  
Author(s):  
Fanglin Zhang ◽  
Philip M. Orton

Low-lying Coastal Landfill Neighborhoods (CLaNs) often have a large aspect ratio, defined here as the coastline length divided by neighborhood width, due to the common practice of reclaiming fringing wetlands along tidal waterways. Flood risk reduction for CLaNs frequently involves elevated barriers, in the form of berms, seawalls, or levees, which reduce risk but cannot completely eliminate residual risk (e.g., due to overtopping during extreme events). Managed retreat is an alternative approach for flood risk reduction, the general idea of which is to strategically ban development in hazard zones, relocate structures, and/or abandon land. This study aims at exploring the tradeoffs between elevated barriers and managed retreat in terms of both CLaN aspect ratio and storm climate, for both short-term and long-term risk reduction with sea-level rise. Hydrodynamic flood modeling of an idealized CLaN protected by different adaptation plans is used to simulate flood conditions and mortality for a range of storm surge amplitudes for both the present-day and under different sea-level rise scenarios. Results show that for a berm and a case of managed retreat of an equal cost, retreat becomes more beneficial than the berm in terms of mortality risk reduction for neighborhoods with a larger aspect ratio. The study also shows that berms are generally less effective for reducing mortality in regions with less common but higher intensity storms. This study reveals the potential of idealized modeling to provide fundamental insights on the physical factors influencing the efficacy of different adaptation strategies for mortality risk reduction.


2022 ◽  
Vol 26 (6) ◽  
pp. 52-62
Author(s):  
G. R. Ramazanov ◽  
E. A. Chukina ◽  
E. V. Shevchenko ◽  
S. A. Abudeev ◽  
E. V. Klychnikova ◽  
...  

The modern integrated approach to the treatment of ischemic stroke (IS), in addition to pharmacotherapy, provides for the impact of physical factors. Among them is injectable carboxytherapy (ICBT). Objective. The aim of the study was to evaluate the effi cacy and safety of using ICBT in combination with a standard treatment program in patients with acute ischemic stroke. Material and methods. The main group (MG) included 39 patients with acute IS, the comparison group (GC) — 31 patients. On the second day of hospitalization, patients with MG underwent ICBT on the background of standard therapy, and GC — procedures that mimic ICBT. Clinical, laboratory and instrumental data, IS outcomes, complications, timing were assessed.Results. There were no statistically signifi cant diff erences in physiological parameters (heart rate, blood pressure, SpO2) between MG and GC during and after the course of treatment. Positive dynamics of the neurological status was observed in both groups in the form of a decrease in the NIHSS score — in the MG from 6 to 4 (p = 0.047), in the GC — also from 6 to 4 (p = 0.25). In patients with MG, trophic disorders were less likely to develop in comparison with GC — 1 (2.6%) versus 6 (19.4%), p = 0.039. ICBT did not aff ect the duration of hospitalization of patients, the duration of treatment in the intensive care unit and carrying of resuscitation and also did not contribute to reducing mortality. Changes in the indicators of the acid-base state of the blood were compensatory in nature and did not lead to changes in the pH of the blood. The decrease in pH from 7.5 to 7.4 in 30–90 minutes after the procedures was a physiological reaction of the body to the introduction of CO2 and was not accompanied by negative consequences. Conclusions. ICBT is a safe method, does not aff ect the duration of hospital stay and mortality, help lower the likelihood of complications.


2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Monire Davoodi ◽  
Behnaz Dindamal ◽  
Hossein Dargahi ◽  
Farzad Faraji-Khiavi

Abstract Background More than three decades of research and study for overcoming the problem of “non-acceptance/non-compliance” of patients has neither resolved nor reduced the severity of this problem. This phenomenological study aimed to identify barriers of adherence to medical advice among type 2 diabetic patients. Methods This study was a qualitative research using phenomenology approach, and the data were analyzed using content analysis approach. Participants were 69 type 2 diabetic patients covered by the diabetes unit of West and East Community Health Centers of Ahvaz, Iran. The views and attitudes of patients about the barriers of adherence to medical advice were elicited by conducting 20–45 min sessions of semi-structured interviews. Data analysis was performed following Colaizzi’s seven-step method. Results Barriers of adherence to medical advice were classified into systemic and individual barriers. Individual barriers included 11 codes and 5 categories, and systemic barriers contained within 5 codes and 3 categories. Physiologic and physical factors, financial problems, occupational factors, attitudinal problems and lack of knowledge, and social and family problems were identified as individual barriers. Systemic barriers included inadequate publicizing and limited notification, inadequate equipment and facilities, and poor inter-sectional coordination. Conclusions Generally, problems stated by diabetic patients at the individual level can partly be solved by training patients and the people around them. However, as for the systemic problems, it seems that solving the barriers of adherence to medical advice requires coordination with other organizations as well as intersection coordination. Overall, these problems require not only comprehensive health service efforts, but also the support of policymakers to resolve barriers at infrastructure level.


Author(s):  
Yask Kulshreshtha ◽  
Philip J. Vardon ◽  
Yi Du ◽  
Guillaume Habert ◽  
Aurélie Vissac ◽  
...  

Earthen construction is re-gaining popularity as an ecological and economical alternative to contemporary building materials. While building with earth offers several benefits, its performance due to water ingress is a concern for its widespread application. This limitation is often solved by adding chemical stabilisers such as Portland cement and hydraulic lime. Chemical stabilisers are a subject of widespread debate as they increase the cost and embodied energy of the structure, and reduce the desirable characteristics of raw or unstabilised earth. This along with perceived environmental performance, renewability, and proven effectiveness in traditional earthen construction has led to a growing interest in biological or organic stabilisers. Although the strengthening mechanism of biological stabilisers is widely covered in scientific studies, discussion regarding the water-resistance is limited. This review aggregates the research from the field of earthen construction and geotechnical engineering and extends it to explain the possible mechanism responsible for the water-resistance behaviour of biologically stabilised earthen materials. This study includes a wide range of traditional and industrial biological stabilisers derived from animals (cow-dung, casein, chitosan), plants (starch, guar gum, cactus mucilage, lignin, tannin) seaweeds (alginate, agar, carrageen) and microbes (xanthan gum, gellan gum). A conceptual model of water-ingress in unstabilised earthen blocks is proposed and the response of biological stabiliser to water ingress and related physico-chemical and physical factors is discussed using the model at microscale (stabiliser interaction with clay, sand) and macroscale (hydraulic conductivity of block). Properties of stabilisers such as hydrophobicity, stability under wet conditions or interaction with cations have a dominant effect on the overall response to water ingress. Key gaps have been identified in the existing knowledge that are necessary to investigate in order to understand the water-resistance behaviour comprehensively. The study concludes with a brief assessment of biological stabilisers based on their performance and feasibility to use in contemporary earthen construction.


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