Comparison Between Radial Basis Function Neural Network and Regression Model for Estimation of Rice Biophysical Parameters Using Remote Sensing

The radial basis function （RBF） emerged as a variant of artificial neural network. Generalized regression neural network （GRNN） is one type of RBF, and its principal advantages are that it can quickly learn and rapidly converge to the optimal regression surface with large number of data sets. Hyperspectral reflectance （350 to 2500 nm） data were recorded at two different rice sites in two experiment fields with two cultivars, three nitrogen treatments and one plant density （45 plants m^-2）. Stepwise multivariable regression model （SMR） and RBF were used to compare their predictability for the leaf area index （LAI） and green leaf chlorophyll density （GLCD） of rice based on reflectance （R） and its three different transformations, the first derivative reflectance （D1）, the second derivative reflectance （D2） and the log-transformed reflectance （LOG）. GRNN based on D1 was the best model for the prediction of rice LAI and CLCD. The relationships between different transformations of reflectance and rice parameters could be further improved when RBF was employed. Owing to its strong capacity for nonlinear mapping and good robustness, GRNN could maximize the sensitivity to chlorophyll content using D1. It is concluded that RBF may provide a useful exploratory and predictive tool for the estimation of rice biophysical parameters.

Vertical development of a Prorocentrum donghaiense bloom in the coastal waters of the East China Sea: coupled biophysical numerical modeling

Algal blooms caused by Prorocentrum donghaiense occurred frequently in the East China Sea （ECS） during spring in recent years. In this study, a coupled biophysical model was used to hindcast a massive P. donghaiense bloom that occurred in 2005 and to determine the factors influencing bloom initiation and development. The model comprised the Regional Ocean Modeling System tailored for the ECS that utilized a multi-nested configuration and a population dynamics model for 19. donghaiense. Comparisons between simulations and observations revealed that the biological model is capable of reproducing the characteristics of 19. donghaiense growth under different irradiances and phosphorus limitation scenarios. The variation of intracellular phosphorus and the effects of 19. donghaiense on ambient nutrients conditions were also reproduced. The biophysical model hindcasted the hydrodynamics and spatiotemporal distributions of the P. donghaiense bloom reasonably well. Bloom development was consistent with observations reported in earlier studies. The results demonstrate the capability of the model in capturing subsurface incubation during bloom initiation. Then model＇s hindcast solutions were further used to diagnose the factors controlling the vertical distribution. Phosphate appeared to be one of the factors controlling the subsurface incubation, whereas surface wind fields played an important role in determining P. donghaiense distribution. The results highlight the importance of nutrient-limitation as a mechanism in the formation of P. donghaiense subsurface layers and the dispersing of P. donghaiense blooms. This coupled biophysical model should be improved and used to investigate 19. donghaiense blooms occurring in different scenarios.

Succession of causative species during spring blooms in the EastChina Sea： coupled biophysical numerical modeling

In the East China Sea(ECS), the succession of causative species responsible for blooms is a recurrent phenomenon during the spring, which changes from diatoms to dinoflagellates. Observations from space and in situ cruises captured this pattern of succession during spring of 2005. In this study, we coupled two biological models, which were developed previously for Skeletonema costatum and Prorocentrum donghaiense,into a circulation model tailored for the ECS. The coupled biophysical model was used to hindcast the blooms and to test the hypothesis proposed in earlier studies that phosphate(PO4 3–) is the first-order decider of the succession. The coupled model successfully reproduced the hydrodynamics(as described in a companion paper by Sun et al.(1), the spatiotemporal distribution of the chlorophyll a(Chl a) concentration, and the species succession reasonably well. By analyzing the effects of different factors on the surface Chl a distribution, we confirmed that the offshore boundaries of the blooms were confined by PO4 3–. In addition, we suggest that surface wind fields may modulate the horizontal distribution of blooms. Thus, during the dispersal of blooms, surface winds coupled with PO4 3– may control the succession of blooms in the ECS. The proposed coupled model provides a benchmark to facilitate future improvements by including more size classes for organisms, multiple nutrient schemes, and additional processes.

Retrieval of canopy biophysical variables from remote sensing data using contextual information

In order to improve the accuracy of biophysical parameters retrieved from remotely sensing data, a new algorithm was presented by using spatial contextual to estimate canopy variables from high-resolution remote sensing images. The developed algorithm was used for inversion of leaf area index (LAI) from Enhanced Thematic Mapper Plus (ETM+) data by combining with optimization method to minimize cost functions. The results show that the distribution of LAI is spatially consistent with the false composition imagery from ETM+ and the accuracy of LAI is significantly improved over the results retrieved by the conventional pixelwise retrieval methods, demonstrating that this method can be reliably used to integrate spatial contextual information for inverting LAI from high-resolution remote sensing images.

An indicator-based approach to assess village-level social and biophysical vulnerability of agriculture communities in Uttarakhand,India

With the growing recognition to myriad forms of current and future threats in the mountain agriculture systems,there is a pressing need to holistically understand the vulnerability of mountain agriculture communities.The study aims to assess the biophysical and social vulnerability of agriculture communities using an indicator-based approach for the state of Uttarakhand,India.A total of 14 indicators were used to capture biophysical vulnerability and 22 for social vulnerability profiles of15285 villages.Vulnerability analysis was done at village level with weights assigned to each indicator using Analytical Hierarchical Process(AHP).The results of the study highlight the presence of very high biophysical vulnerability(0.82 ± 0.10) and high social vulnerability(0.65 ± 0.15) within the state.Based on the results,it was found that incidences of high biophysical vulnerability coincide with presence of intensified agriculture land and absence of dense forest.Higher social vulnerability scores were found in villages with an absence of local institutions(like Self Helping Groups(SHGs)),negligible infrastructure facilities and higher occupational dependence on agriculture.A contrast was observed in the vulnerability scores of villages present in the three different altitudinal zones in the study area,indicating respective vulnerability generating conditions existing in these three zones.Biophysical vulnerability was recorded to be highest in the villages falling in the lower zone and lowest in the upper zone villages;whereas,social vulnerability was found to be highest in the middle zone villages and lowest in lower zone villages.Our study aids policy makers in identifying areas for intervention to expedite agriculture adaptation planning in the state.Additionally,the adaptation programmes in the region need to be more context-specific to accommodate the differential altitudinal vulnerability profiles.

Evaluation and Exploitation of Retrieval Algorithms for Estimating Biophysical Crop Variables Using Sentinel-2,Venus,and PRISMA Satellite Data

This paper is devoted to the development and testing of the optimal procedures for retrieving biophysical crop variables by exploiting the spectral information of current multispectral optical satellite Sentinel-2 and Venus and in view of the advent of the new Sino-EU hyperspectral satellite(e.g.,PRISMA,EnMAP,and GF-5).Two different methodologies devoted to the estimation of biophysical crop variables Leaf area index(LAI)and Leaf chlorophyll content(Cab)were evaluated:non-kernel-based and kernel-based Machine Learning Regression Algorithms(MLRA);Sentinel-2 and Venus data comparison for the analysis of the durum wheat-growing season.Results show that for Sentinel-2 data,Gaussian Process Regression(GPR)was the best performing algorithm for both LAI(R 2=0.89 and RMSE=0.59)and Cab(R 2=0.70 and RMSE=8.31).Whereas,for PRISMA simulated data the Kernel Ridge Regression(KRR)was the best performing algorithm among all the other MLRA(R 2=0.91 and RMSE=0.51)for LAI and(R 2=0.83 and RMSE=6.09)for Cab,respectively.Results of Sentinel-2 and Venus data for durum wheat-growing season were consistent with ground truth data and confirm also that SWIR bands,which are used as tie-points in the PROSAIL inversion,are extremely useful for an accurate retrieving of crop biophysical parameters.

A numerical study of coupled maps representing energy exchange processes between two environmental interfaces regarded as biophysical complex systems

The field of environmental sciences is abundant with various interfaces and is the right place for the application of new fundamental approaches leading towards a better understanding of environmental phenomena. Following the definition of environmental interface by Mihailovic and Bala? [1], such interface can be, for example, placed between: human or animal bodies and surrounding air, aquatic species and water and air around them, and natural or artificially built surfaces (vegetation, ice, snow, barren soil, water, urban communities) and the atmosphere, cells and surrounding environment, etc. Complex environmental interface systems are (i) open and hierarchically organised (ii) interactions between their constituent parts are nonlinear, and (iii) their interaction with the surrounding environment is noisy. These systems are therefore very sensitive to initial conditions, deterministic external perturbations and random fluctuations always present in nature. The study of noisy non-equilibrium processes is fundamental for modelling the dynamics of environmental interface regarded as biophysical complex system and for understanding the mechanisms of spatio-temporal pattern formation in contemporary environmental sciences. In this paper we will investigate an aspect of dynamics of energy flow based on the energy balance equation. The energy exchange between interacting environmen- tal interfaces regarded as biophysical complex systems can be represented by coupled maps. Therefore, we will numerically investigate coupled maps representing that exchange. In ana- lysis of behaviour of these maps we applied Lyapunov exponent and cross sample entropy.

Tmod1 Affects the Immune Functions and Biophysical Properties of Dendritic Cells Through TLR4 Signaling Pathway and Cytoskeleton Remodeling

Background Dendritic cells(DCs)are the most important antigen-presenting cells due to their professional and extremely efficient antigen-presenting function.The dynamics of cytoskeleton plays crucial regulated roles on DCs’immune functions and biophysical properties.Several evidences show that tumor-derived suppressive cytokines deteriorate DCs’immune functions through remodeling their F-actin cytoskeleton.But the underlying mechanism is still elusive.Tropomodulin1(Tmod1),a cytoskeleton-binding protein,regulates and stabilizes actin filaments lengths and cytoskeleton architecture,which involves in the regulations of the morphology,formation of neural dendrites and biophysical properties of cells.Our previous studies found that mature DCs(mDCs)had a higher expression of Tmod1 than immature DCs(imDCs). Therefore,it’s hypothesized that Tmod1 maybe involve in the modification of DCs’functions.Objective The aim of the study is to investigate the effects of Tmodl on the immune functions and biophysical properties of DCs and the underlying mechanisms in order to further understand the biological behaviors of DCs.Methods Bone marrow-derived cells were harvested from wild type(C57BL/6 J)mice and Tmod1 knockout mice(Tmod1 overexpressing transgenic(TOT)/Tmod1-/-)and differentiated to immature dendritic cells(imDCs)by rmGM-CSF and rmIL-4.imDCs were then matured by lipopolysaccharides(LPS)treatment.The expressions of the surface markers in DCs,including CD80,CD86,CD40,MHC-Ⅱand CCR7,were detected by flow cytometry,Western blot and qRT-PCR.The inflammation cytokines such as IL-6,IFN-γ,IFN-βand IL-10 were also detected by flow cytometry.The immune functions and the biophysical properties of DCs were compared between the wild type and Tmod1 knockout mice.The F-actin content and dendritic pseudopodia of these two kinds of DCs were detected by flow cytometry and laser scanning confocal microscope respectively.Finally,we detected the MyD88 dependent and independent signaling pathway to discover the molecular mechanisms.Results We found that Tmod1-deficient mDCs showed deficient antigen-presenting ability and they failed to express enough MHC-Ⅱ,co-stimulated molecules(CD80/86,CD40)and CCR7 on their cell surface.The secretions of the inflammatory cytokines IL-6 and IFN-γwere decreased while the anti-inflammatory cytokines IFN-βand IL-10 were increased in the supernatant of Tmod1-deficient mDCs.As compared to DCs of wild type mice,the migration ability of DCs from Tmod1 knockout mice were dramatically damaged including their free migration and CCL19 mediated chemotaxis migration.However,we found that Tmod1 knockout had no effects on the imDCs’endocytosis ability.Furthermore,Tmod1 knockout DCs showed higher osmotic fragility,lower Young’s modulus,less F-actin content and shorter dendritic pseudopodia.Under LPS stimulation,the phosphorylation level of p65 and p38 were significantly downregulated in Tmod1 knockout mice while the expression of p-IRF3 was upregulated.Conclusions These results indicated that Tmodl knockout leads to deficient antigen-presenting ability and impaired migration of DCs as well as their biophysical properties.The underlying mechanisms are due to the inhibitions of the TLR4-mediated NF-κB and p38 MAPK singling pathway and the activation of the IRF3 signaling pathway,as well as the disturbed reorganization of the F-actin cytoskeleton.Our results provide a new insight on the functions of Tmod1 which can affect the DCs’immune functions and biophysical properties through regulating the TLR4-mediated singling pathways and cytoskeleton remodeling.

Effect of Biophysical Cues on Cell Reprogramming

Cell reprograming technologies have broad applications in cell therapy,disease modeling and drug screening.Direct reprogramming is the process of converting from one cell type into a very distantly related cell type.In this direct conversion process,cells do not proceed through a pluripotent stage,which can be time-consuming and challenging due to spontaneous differentiation.This method also offers the advantage of circumventing the teratoma potential that is associated with using iPSCs.Previous works have demonstrated that with the use of genetic manipulation,fibroblasts can be directly converted into other cell types,including neurons,cardiomyocytes,blood cell progenitors,and hepatocytes.It is well known that the microenvironment can directs cell fate,and in turn cells interact with or remodel their niches.Accumulative evidence suggests that biophysical factors such as the microtopography and mechanical property of cell adhesive substrates regulate a variety of cellular functions such as migration,proliferation and differentiation,which in turn can modulate wound healing,tissue remodeling and tumor growth,but there are limited number of studies on the roles of biophysical cues in cell reprogramming[1].Passive topographical cues offer a simple and effective method to improve reprogramming efficiency without the need for biochemical manipulations.Our previous study has demonstrated that somatic cells cultured on the parallel microgrooves,which can replace the effects of small-molecule epigenetic modifiers and significantly improve the iPSCs reprogramming efficiency.The mechanism relies on the mechanomodulation of the cells’epigenetic state,specifically,an increase of histone H3 acetylation and H3K4 methylation[2].Additionally,in cardiomyocytes reprogramming study,culturing the fibroblasts on microgrooved substrate enhances the expression of cardiomyocyte genes by day 2 and improves the yield of partially reprogrammed cells at day 10.By combining microgrooved substrate with an optimized culture protocol,the conversion from fibroblasts to cardiomyocytes is increased through genetic changes and structural organization of sarcomeres[3].Besides biomaterial topography,recent studies have demonstrated the effects of matrix stiffness on cell reprogramming.For example,a decrease of substrate stiffness can improve the iPSCs reprogramming efficiency,while an intermediate stiffness can significantly enhance the efficiency of neuronal reprogramming [4].Further analysis suggests that intracellular biomechanical changes play an important role in reprogramming process.Cells interact with the biophysical factors in the microenvironment through an'inside-out'and'outside-in'feedback loop,which is mediated by focal adhesions and cytoskeleton [5].Therefore,we investigated the role of the intracellular mechanical structure in cell reprogramming.We showed,for the first time,that the mechanical property of cells was modulated during the early phase of reprogramming as determined by atomic force microscopy(AFM)and high-throughput quantitative deformability cytometry(q-DC).We observed that cell stiffness increased by day 1 during reprogramming process,which was followed by a pronounced decrease within a few days.Examination of actin cytoskeleton showed that actin assembled into a network with a cage-like structure around the nucleus by day 1,but this structure along with the majority of the cytoskeleton gradually disappeared,coinciding with the changes in intracellular mechanical property.Furthermore,inhibition of actin contractility by using small molecules significantly altered the reprogramming efficiency.These findings provide new insights into the mechanisms of how biophysical cues modulate cell fate.In any given physiological microenvironment,cells may experience various of biophysical inputs,which,as we show,may affect cell phenotype changes.

The Challenge of Improving IVF Results in Normogonadotrophic (Unexpected) Young Poor Ovarian Responders: The Predictive Value of a Flexible Treatment Protocol Based on the “Biophysical Profile of the Uterus”

Objective: To study whether the unexpected poor ovarian responders optimization of uterine receptivity with a flexible controlled ovarian hyper stimulation protocol based on the Biophysical Profile of the Uterus, has an impact on their reproductive performance. Design: Observational Prospective study. Setting(s): i) General hospital-IVF and Infertility Centre;ii) University hospital. Patient(s): 44 normogonadotrophic young women (26 - 38 yrs) with previous “unexpected” poor ovarian response underwent IVF/ICSI treatment on a protocol based on the Biophysical Profile of their uterus (Group A). The same patients were used as controls in a preceded IVF cycle on the conventional stimulation protocol. Intervention(s): None. Main outcome measure(s): Pregnancy, miscarriage and home take baby rates, amount and duration of gonadotropins required, number and quality of embryos resulted, Biophysical Profile of the Uterus score. Result(s). Treatment in Group A in comparison to Group B resulted in significantly larger number of eggs retrieved per patient, and improved fertilization rates and higher number of embryos/ET (p = 0.011, 0.010 and 0.034 respectively). Group A also demonstrated a trend for higher rates of clinical pregnancy (29.5% v.s. 15.9%), viable stage pregnancies ≥ 24 weeks (33.3% v.s. 20%) and home take babies (26.6% v.s. 16%). The amount of gonadotropins used per patient (IU) was similar in the two groups (p = 0.264). Cancellation, implantation and miscarriage rates as well as embryos quality, although superior in the treatment Group A, showed no significant difference. The number of pregnancies achieved in Group A, were directly related with the score in the Biophysical Profile of the Uterus 12 point scale. Conclusion(s): Unexpected Poor Ovarian Responders on the flexible IVF/ICSI protocol (Group A), adjusting the management according to the Biophysical Profile of their uterus (duration of stimulation, day of HCG and day of embryo transfer), had a significantly better performance in comparison to the Group B managed on the conventional protocol in this difficult to manage and so far, rather understudied population.

The Effects of Sleep Deprivation on the Biophysical Properties of Facial Skin

Lack of sleep is a problem in today’s society, and many people are concerned about changes in their outward appearance due to lack of sleep. People generally come up with some noticeable skin attributes as symptoms of sleep deficiency including rough, dull, and dry skin as well as droopy eyelids and dark eye circles. Several previous reports also suggested that poor sleep could affect the skin condition. The purpose of this study was to evaluate the effect of one night of sleep deprivation on various skin biophysical properties. Twenty four healthy females participated in a study of one night of sleep deprivation. Subjects were kept awake for one night in a laboratory with controlled temperature and relative humidity. The skin condition of each subject was evaluated after normal sleep pattern and after one night of sleep deprivation. The measured skin biophysical parameters included transepidermal water loss, facial pore size, and skin tone, hydration, elasticity, desquamation, translucency, and blood flow. The cheek, eye, and lip areas were evaluated. After one night of sleep deprivation, multiple skin biophysical parameters showed changes when compared to the baseline measurements. A significant decrease in skin hydration and impaired barrier function were observed (p < 0.05). Decreased hydration led to decreased skin elasticity and translucency and increased skin scaling (p < 0.05). Facial pores were more conspicuous, and skin lightness decreased significantly (p < 0.05). Furthermore, skin blood flow decreased prominently (p < 0.05). The results demonstrated that the skin features that are recognized as symptoms of sleep deficiency actually showed remarkable differences after a period of sleep deprivation, and some of these features were confirmed in the eye, lip, as well as the cheek areas. This study revealed a significant association between sleep deprivation and skin biophysical properties by scientific measuring.

Population-based affective-disorder-related biomedical/biophysical multi-hyper-morbidity across the lifespan:A 16-year population study

BACKGROUND There are few if any life-span population-based studies of psychiatric disorderassociated biomedical and biophysical disorders and diseases(morbidity).AIM To scope the present state of research regarding the biomedical and biophysical morbidity associated with affective and mental disorder in epidemiological samples,and to examine the life-span relationship between affective disorders and biomedical/biophysical disorders to illustrate a novel approach employing the odds ratio to represent the intensity of biomedical and biophysical morbidity associated in time in a population.METHODS A repeatable systematic literature search of PubMed was represented in summary.Additionally,a regional population-based dataset was constructed and analyzed to represent the age-and sex-specific diagnoses(International Classification of Diseases Version 9,ICD-9)for those with and without affective disorder.The analysis presents a novel index of the relative age-specific frequency of life-span biomedical and biophysical diagnoses associated with affective disorder.RESULTS The volume of biomedical and biophysical morbidity associated with mental disorder literature has increased,yet few studies measure comprehensive temporal hyper-morbidity(over-representation of diseases over time,either before or after the index diagnostic event)in populations.Further,there have been only a few population-based studies examining the morbidity associated with affective disorder and only one that examines the full diagnostic range of lifespan morbidity.Substantial differences arose between males and females with more females than males having greater frequencies of diagnoses.The age-specific distributions of the maximum proportional diagnosis frequency ratios for each sex illustrate the greatest diagnosis-specific differences when comparing the biomedical and biophysical diagnoses of those with and without affective disorder when the same diagnosis was represented in each grouping at the same age.CONCLUSION Clinical research needs to focus on more than one or two comorbid biomedical or biophysical disorders at a time.Comprehensive population-based examination of the lifespan biomedical and biophysical multi-morbidity associated with affective disorder has the potential to directly inform clinical practice.Representing the proportional ratios of age-specific frequency of diagnoses for the full range of ICD-9 diagnoses is a novel analytical model.Diagnostic frequency appears a viable representation of a given disease state,such as affective disorder.Fortunately,the WPA has developed a global education section to better understand the biomedical and biophysical morbidity associated with all psychiatric disorders.This has been identified by the WPA as the psychiatric practice challenge of the 21st century.

Sensitivity of X-Band (σ0, γ) and Optical (NDVI) Satellite Data to Corn Biophysical Parameters

The objective of this work was to evaluate the sensitivity of three different satellite signals (interferometric coherence (γ), backscattering coefficient (σ0) and NDVI) to corn biophysical parameters (leaf area index, height, biomass and water content) throughout its entire vegetation cycle. All of the satellite and in situ data were collected during the Multi-spectral Crop Monitoring (MCM’10) experiment conducted in 2010 by the CESBIO Laboratory over eight different agricultural sites located in southwestern France. The results demonstrated that the NDVI is well adapted for leaf area index monitoring, whereas γ27.3° is much more suited to the estimation of the three other Biophysical Parameters throughout the entire crop cycle, with a coefficient of determination ranging from 0.83 to 0.99, using non-linear relationships. Moreover, contrary to the use of the NDVI or backscattering coefficients, the use of coherence exhibited a low sensitivity to the changes in vegetation and soil moisture occurring during senescence, offering interesting perspectives in the domain of applied remote sensing

Kala-Azar： Nature, Biophysical Aspects, Clinical Manifestation and Treatment

The aim of this study is to focus on a disease with a potential global health risk--VL （visceral leishmaniasis） or kala-azar. By understanding the mechanism of occurrence, development and countering infection, we can expect significant improvement in the indicators of morbidity and mortality. The specific method of transmission, as well as the necessary conditions for it, opens wide opportunities for prevention. The biophysical aspects that we present make it possible to assess the seriousness of the advancing physiological changes. This ensures adequate evaluation of the associated risks and search for an optimal therapy. We have found that from the first manifestations ofkala-azar up until today, a series of countermeasures have been taken up. Acknowledging and expecting the massiveness of the infectious process, it is possible for it to cover areas whose population is unprepared to handle the contamination optimally. This requires the continuation of studies aimed at finding the most affordable and biologically tolerable medicine. The available treatment option for visceral leishmaniasis is problematic when it comes to efficacy, adverse effects and cost, making the treatment a complex issue. Not to mention toxicity of the drugs, ability to monitor side effects, length of treatment and capacity of the healthcare service to administer an accurate therapy. The main drugs available for treatment of VL （visceral leishmaniasis） are systemic agents like Antimony, Amphotericin and nowadays the oral drug Miltefosine.

Biophysical Evaluation of the Vadose Zone at a Landfill Site in the Niger Delta, Nigeria

The vadose zone of a landfill site proposed as an integrated waste management facility was evaluated based on geohydrological, chemical and microbiological characteristics of the groundwater and underlying soil. These data were also used to assess the attenuation capacity of the zone by the use of microbial degradation test of some major constituents including fatty acids, organic nitrogen and chloride of the leachate for a 28-day period. The main soil type in vadose zone consisted of brownish clayey sand of low permeability. The depth to water table which is equal to the thickness of the vadose zone varied from 8 - 13 m. Groundwater flowed with a hydraulic gradient of approximately 4.0 × 10Dž and a pore velocity of 1.6 × 10Dž cm/sec. The results of the biodegradation tests showed that the major constituents of the leachate such as ammonia/organic nitrogen, phosphate and organic carbon were completely degraded within 28 days. The population of aerobic bacteria within the 6 m soil depth was sufficient to bring about over 0.05% organic carbon removal. The soil characteristics in the vadose zone are very favourable for the occurrence of natural attenuation. The potential natural attenuation capacity of the vadose zone is therefore classified as moderate to high.

Study of the Impact of the Patient Rhythm during Cryoballoon Ablation on the Acute Biophysical Parameters

Background: Pulmonary vein isolation by means of cryoballoon is a well-established way of treatment of atrial fibrillation. The aim of the study was to compare the acute cryoballoon biophysical parameters attained during energy applications to the individual pulmonary vein during sinus rhythm versus atrial fibrillation. Methods: 100 Patients who underwent their first-time PVI using second-generation cryoballoon for symptomatic and drug-refractory AF, between the beginning of March to end of August 2016, were initially screened. 61 patients with paroxysmal AF were included in the present study. 39 patients with persistent AF were excluded. No pre-procedural anatomical imaging was reported. Results: A total of 61 patients (male 80%, age 59.3 ± 13.4 years) were included in the present analysis. A total of 243 pulmonary veins were isolated with an average of 1.87 ± 1.14 cryo energy applications per individual vein. During cryo application, there were no significant differences between applications delivered during sinus rhythm or ongoing AF in the rate of temperature drop at 5 and 30 s, rate of warming at 5 s after freezing stop or achieved balloon nadir temperature. The same also was observed for both the balloon cooling rate and warming times. Conclusions: The present analysis shows no impact of the patient baseline rhythm at the time of energy application upon the acute balloon biophysical parameters in patients with normal sinus rhythm and those with ongoing atrial fibrillation using the second-generation cryoballoon.

Biophysical cues involved in the stem cell niche for stemness maintenance

The characteristics of stem cells are self-renewal ability and differentiation potential.These properties are defined as stemness,offering them application in tissue repair and regeneration based on stem cells with great promise.However,stem cells undergo functional deterioration and gradually lose stemness with long-term expansion.Accumulating evidence implies that the regulation of stemness is primarily orchestrated by the niche,which comprises the connection between stem cells and niche cells,extracellular matrix(ECM)proteins,and secreted factors.Increasingly,physical signals are being acknowledged as paramount regulators of cellular behavior,governing stem cell stemness,tissue development,and regeneration.This review outlines current approaches for stemness maintenance and the important biophysical cues involved in the stem niche.We first encompass the latest discoveries regarding the sources and transduction pathways of these biophysical cues.Subsequently,the specific biophysical factors for regulating stemness have been described.Moreover,we summarize existing challenges and prospect future research in this field.

Estimating biophysical parameters of rice with remote sensing data using support vector machines

Hyperspectral reflectance (350-2500 nm) measurements were made over two experimental rice fields containing two cultivars treated with three levels of nitrogen application.Four different transformations of the reflectance data were analyzed for their capability to predict rice biophysical parameters,comprising leaf area index (LAI;m-2 green leaf area m-2 soil) and green leaf chlorophyll density (GLCD;mg chlorophyll m 2 soil),using stepwise multiple regression (SMR) models and support vector machines (SVMs).Four transformations of the rice canopy data were made,comprising reflectances (R),first-order derivative reflectances (D1),second-order derivative reflectances (D2),and logarithm transformation of reflectances (LOG).The polynomial kernel (POLY) of the SVM using R was the best model to predict rice LAI,with a root mean square error (RMSE) of 1.0496 LAI units.The analysis of variance kernel of SVM using LOG was the best model to predict rice GLCD,with an RMSE of 523.0741 mg m-2.The SVM approach was not only superior to SMR models for predicting the rice biophysical parameters,but also provided a useful exploratory and predictive tool for analyzing different transformations of reflectance data.

Ultrasound-induced biophysical effects in controlled drug delivery

Ultrasound is widely used in biomedical engineering and has applications in conventional diagnosis and drug delivery.Recent advances in ultrasound-induced drug delivery have been summarized previously in several reviews that have primarily focused on the fabrication of drug delivery carriers.This review discusses the mechanisms underlying ultrasound-induced drug delivery and factors affecting delivery efficiency,including the characteristics of drug delivery carriers and ultrasound parameters.Firstly,biophysical effects induced by ultrasound,namely thermal effects,cavitation effects,and acoustic radiation forces,are illustrated.Secondly,the use of these biophysical effects to enhance drug delivery by affecting drug carriers and corresponding tissues is clarified in detail.Thirdly,recent advances in ultrasound-triggered drug delivery are detailed.Safety issues and optimization strategies to improve therapeutic outcomes and reduce side effects are summarized.Finally,current progress and future directions are discussed.

Influences of agricultural phenology dynamic on land surface biophysical process and climate feedback

Response and feedback of land surface research priorities in the field of geoscience. The process to climate change is one of the current study paid more attention to the impacts of global change on land surface process, but the feedback of land surface process to climate change has been poorly understood. It is becoming more and more meaningful under the framework of Earth system science to understand systematically the relationships between agricultural phenology dynamic and biophysical process, as well as the feedback on climate. In this paper, we summarized the research progress in this field, including the fact of agricultural phenology change, parameterization of phenology dynamic in land surface progress model, the influence of agricultural phenology dynamic on biophysical process, as well as its feedback on climate. The results showed that the agriculture phenophase, represented by the key phenological phases such as sowing, flowering and maturity, had shifted significantly due to the impacts of climate change and agronomic management. The digital expressions of land surface dynamic process, as well as the biophysical process and atmospheric process, were improved by coupling phenology dynamic in land surface model. The agricultural phenology dynamic had influenced net radiation, latent heat, sensible heat, albedo, temperature, precipitation, circulation, playing an important role in the surface energy partitioning and climate feedback. Considering the importance of agricultural phenology dynamic in land surface biophysical process and climate feedback, the following research priorities should be stressed： （1） the interactions between climate change and land surface phenology dynamic; （2） the relations between agricultural phenology dynamic and land surface reflectivity at different spectrums; （3） the contributions of crop physiology characteristic changes to land surface biophysical process; （4） the regional differences of climate feedbacks from phenology dynamic in different climate zones. This review is helpful to accelerate understanding of the role of agricultural phenology dynamic in land surface process and climate feedback.