Catastrophic Characteristics Research Articles

A catastrophe identification method for rainfall time series coupled sequential Mann-Kendall algorithm and Bernaola Galvan algorithm: a case study of the Qinglong River watershed, China

AbstractThe identification of rainfall catastrophe characteristics is important for rainfall consistency testing in hydrostatistical analysis. In this study, a new classification method (trend, mean and change-rate catastrophe) was proposed and applied to the Qinglong River watershed, Northern China. Two groups of algorithms were compared to obtain the optimal algorithm: the Cumulative-anomaly method and the Sequential Mann-Kendall (SQ-MK) algorithm, the Pettitt algorithm and the Bernaola-Galvan heuristic segmentation (B-G) algorithm. Its parameters were optimized and its robustness was tested. Results revealed that: (1) The SQ-MK algorithm was suitable for trend catastrophe and sensitive to the length of the time series. The most significant point of trend catastrophe in the Qinglong River watershed was in 2012. (2) The sensitivity of parameter P0 (Range value (R) = 4.333) in the B-G algorithm was greater than that of parameter l0 (R = 2.889). (3) The B-G algorithm was suitable for identifying mean catastrophes and insensitive to the length of the time series. In the Qinglong River watershed, mean catastrophe points were identified in 1997, 2002, 2004, 2006, 2009, 2012, and 2018. (4) There was no change-rate catastrophe point in the Qinglong River watershed. Trend catastrophe and mean catastrophe do not necessarily lead to change-rate catastrophe.

The effect of sanguinarine on the RPMI-7951 and A375 melanoma cell lines

Background: Considering the resistance of melanoma to standard treatment protocols, the possibility of metastasis and the high mortality risk, the selection of new alternatives seems to be necessary. Compounds of natural origin are a promising option in anti-cancer therapy. One of them — sanguinarine has a wide spectrum of pro-health properties. Thus, the study aimed to assess the effect of the alkaloid on selected melanoma cellular models. Material and methods: Two types of melanoma cell lines were used in the study — A375 and RPMI-7951. The cells were treated with sanguinarine at concentrations ranging from 0.1 to 2 μM for 24 and 48 h. The influence of the alkaloid on such processes as cell death, cell cycle, organization of the main cytoskeletal proteins and migration potential was assessed. In addition, the sensitivity of selected cell lines to sanguinarine was evaluated based on the MTT assay. Results: The results showed that sanguinarine caused a dose-dependent decrease in cell survival compared to the untreated control. Further studies confirmed that it resulted from the pro-apoptotic and anti-proliferative action of the alkaloid. There were also significant changes in the organization of cytoskeletal proteins and the number of cells visible after fluorescent labelling. Moreover, in A375 cells, characteristics of entosis and mitotic catastrophe were noted. Sanguinarine-induced impaired cell migration was also confirmed. Conclusion: According to the authors’ knowledge, they are the first to present the influence of sanguinarine on the basic life processes of the RPMI-7951 cell line and supplement the knowledge regarding the A375 melanoma cells. The present results confirm the anticancer properties of the alkaloid (cytotoxicity, anti-migratory and pro-apoptotic effect).

Study on the mechanism of tunnel catastrophe in Xigeda formation considering the interbed effect

The Xigeda formation, widely distributed in southwestern China, is a special semi-diagenetic rock with horizontal bedding，which is mudding in water. In order to study the failure law, catastrophe characteristics and catastrophe mechanism of the interbed type to the surrounding rock and structure of Xigeda formation tunnel, this paper, by means of field investigation, indoor test, numerical simulation, field monitoring and theoretical research, relying on more than ten Xigeda formation tunnels in the Chengdu-Kunming double track railway, analyzes the apparent failure characteristics and catastrophe mechanism of the surrounding rock of Xigeda formation tunnels with different interbed types. The results show that: the catastrophe characteristics of Xigeda formation tunnel have certain water content sensitive area and influence area division of interbed type. The water content of Xigeda formation is 25% - 30% of the catastrophic critical region of Xigeda formation tunnel. In this critical region, the vault of the overlying Xigeda formation tunnel is prone to large deformation, the invert of the underlying Xigeda formation tunnel is prone to large uplift deformation, and the side wall and tunnel face of interlayer Xigeda formation tunnel are prone to large extrusion deformation; when the water content of Xigeda formation is 30%, it becomes a weak layer, and under the effect of interbed, the rock and soil of Xigeda formation are prone to large deformation, resulting in catastrophes by extruding the tunnel structure; based on the analysis of chemical effect, physical effect and mechanical effect, the structural components of interbed rock chemically react with water, leading to weakening of the strength and causing catastrophic effects. The catastrophic effect is similar to that of simply supported beam in the strong and weak regions of the interbed, while the weakening effect of the interlayer structural plane leads to the opening of the interlayer fracture plane of the tunnel surrounding rock and the large interlayer dislocation displacement, which forces the shear failure of the supporting structure. The research results of this paper can provide theoretical guidance for the Sichuan-Tibet railway to be constructed.

Aspirin Restores Radiosensitivity in Cervical Cancer Cells by Inducing Mitotic Catastrophe through Downregulating G2/M Effectors.

Compromised cell-cycle checkpoint is a major obstacle for rendering radiotherapeutic success of radioresistant cells. Aspirin (ASA), an anti-inflammatory agent was repurposed previously for improving radiotherapy by limiting radiation toxicity. However, the underlying mechanism was unclear. The present study aimed to identify the mechanism of ASA mediated reversal of radioresistance in cervical cancer cells. Radioresistant subline SiHa/RR was developed from parental cervical squamous carcinoma cell line SiHa by chronic fractionated irradiation (IR). The radioresistance property of SiHa/RR was confirmed by clonogenic assay. Alteration in cell-cycle by ASA was determined by flow cytometry. ASA induced nuclear damage as consequence of mitotic catastrophe was confirmed by microscopic observation. The interaction between ASA and G2/M regulators was explored through in silico docking analysis and expressional change of them was affirmed by western blotting. Immunofluorescence study to examine Aurora Kinase A localization in presence and absence of ASA treatment was conducted. Finally the radiosensitizing ability of ASA was verified by apoptotic parameters (flow cytometrically and by western blotting). Higher colony forming ability of SiHa/RR compared to SiHa became restrained upon ASA (5μM) treatment prior to IR. Flow cytometric analysis of ASA treated cells showed increased G2/M population followed by enlargement of cells displaying giant multinucleated morphology; typical characteristics of mitotic catastrophe. Underlying noteworthy mechanisms involved decreased expressions of G2/M regulatory proteins (Cyclin B1, CDK1, Aurora A Kinase, pAurora A Kinase) in IR/ASA along with inhibiting nuclear localization of Aurora Kinase A in SiHa/RR. Docking results also supported the findings. Prolonged treatment (12 h) with ASA led to apoptosis by altering expressions of Bcl2, Bax and Cytochrome C; which was achieved through the event of mitotic catastrophe. This work established that G2/M arrest and mitotic catastrophe can be considered as the principle mechanism of restoration of radiosensitivity in SiHa/RR by ASA pretreatment.

Nip risk in the bud: A system dynamic model to govern NIMBY conflict

“Not In My Backyard” (NIMBY) conflict refers to public resistance to the government in delivering and operating NIMBY facilities. Although the antecedents of NIMBY conflicts are widely explored (e.g., negative externalities, public sensitivity, external triggers), there is rare literature systematically exploring their integrated effects on public resistance from the public social psychology perspective that considers the interplaying effects of public risk and emotion perception. Besides, to reflect the nonlinear change of public resistance (i.e., “emergency” and “discontinuity” features of NIMBY conflict), we originally integrate the catastrophe theory into the system dynamic method to establish an SD-Catastrophe model to simulate the evolution process of public resistance behavior. The effect of governmental response on NIMBY conflicts is especially examined in the simulation model, and the catastrophe characteristics of public resistance behavior in NIMBY conflict are verified. The result shows that governmental response contributes to eliminating NIMBY conflicts in four aspects: 1)Different facilities, different urgency; 2) The faster, the better; 3) The higher intensity, the better; and 4) Existing effect lag. Based on the nonlinear change of public resistance, two governance strategies, including the internal strategy (i.e., optimizing public psychological states) and the external strategy (i.e., controlling project external triggers), are formulated to help the government eliminate the risk of NIMBY conflict.

The Theoretical Research on Grey Catastrophe Model of Traffic System

As we all know, it is difficult for traditional traffic models to deal with the phenomenon of “catastrophes” in traffic state and the traffic problem with incomplete information at the same time. Aiming at the traffic congestion, this paper firstly takes traffic volume as a state variable, speed, and density as control variables to establish the system potential function and theoretically clarifies that the structure of the traffic system has catastrophe characteristics. Secondly, combined with the grey characteristics of traffic system, we construct the grey catastrophe model for traffic system and obtain the traffic potential function with the system time as the state variable by substituting the variables of the model. Finally, the traffic stability is analyzed theoretically based on the potential function. In this paper, the rationality of the grey catastrophe model of traffic system is expounded theoretically, and the grey model theory is well expanded.

Research on Mechanisms and Control Measures of Surrounding Rock Disaster in Large Section Roadway with Top Coal under the Influence of Tectonic Stress

Based on the research background of large section roadway with top coal (LSRTC) in thick coal seam mining in Wangzhuang Coal Mine, Shanxi Province, China, catastrophe characteristics of the surrounding rock of the LSRTC were investigated and summarized. Based on the principle of damage mechanics, the critical size discriminant of the LSRTC was deduced, and the induction mechanism of section size effect and tectonic stress effect on the roadway surrounding rock disaster was revealed. Accordingly, the roadway surrounding rock control principle with the basic idea of “stabilizing and controlling top coal, reconstructing the coal wall, and limiting floor heave” was put forward, and the roadway surrounding rock stability control countermeasures with the core technology of “strong pressure support for roof + grouting reinforcement for two sides + bolt barrier for floor angle” were developed, which solved the surrounding rock control problem of the LSRTC under the action of tectonic stress and provided a useful reference for the difficult problem of roadway surrounding rock control under similar conditions.

Research on the Traffic Flow Control of Urban Occasional Congestion Based on Catastrophe Theory

Aimed at the problem of occasional congestion control, the cusp catastrophe theory is used to establish the catastrophe model of the urban road system under occasional congestion, finding breakpoints and analyzing stability after urban road system catastrophes by constructing the energetic function; based on the catastrophe characteristics of the urban road system, the feasibility method of congestion control is discussed. The results show that the control method of traffic flow based on catastrophe characteristics of the urban road system can effectively improve the efficiency of the road system in theory. Finally, the applicability of the control method based on catastrophe characteristics is analyzed by examples under different occasional congestion situations.

재난 시대의 인문학을 생각하며

This paper suggests that the current outbreak of coronavirus be approached both as a singular event with its own catastrophic characteristics and as one of many disasters that have constantly plagued the modern world. To define the corona pandemic as a disaster is, by definition, to say that it is absolutely unpredictable precisely because the way our modern knowledge, culture, and civilization have been structured to systematically blind us to the impact and consequences of the disaster. A disaster, in other words, demands that we should engage with our past and present from a radically new perspective that defies the conventional thoughts available prior to the disaster. The unpredictability of the disaster, thus, leads us to the invention of new concepts and politics that necessarily problematizes the vulnerability of our community. However, given that the infodemic that accompanies the corona pandemic has been fueled by economic as well as political attempts to directly profit from the large-scale crisis and to exploit the affective fluctuations, what is urgent is a genuinely collective thought that explores the conditions of possibility for the security of the whole community. In other words, the search for the collective right/ responsibility for security cannot be done within the confines of narrowly national, commercial, parochial interest. If everyone is vulnerable to the disaster, then whatever politics emerging from the disaster should be based upon the totality of community. And the invention of the forms and practices of common security is the task of Humanities in the age of disaster.

Ionizing radiation results in a mixture of cellular outcomes including mitotic catastrophe, senescence, methuosis, and iron-dependent cell death

Radiotherapy is commonly used as a cytotoxic treatment of a wide variety of tumors. Interestingly, few case reports underlined its potential to induce immune-mediated abscopal effects, resulting in regression of metastases, distant from the irradiated site. These observations are rare, and apparently depend on the dose used, suggesting that dose-related cellular responses may be involved in the distant immunogenic responses. Ionizing radiation (IR) has been reported to elicit immunogenic apoptosis, necroptosis, mitotic catastrophe, and senescence. In order to link a cellular outcome with a particular dose of irradiation, we performed a systematic study in a panel of cell lines on the cellular responses at different doses of X-rays. Remarkably, we observed that all cell lines tested responded in a similar fashion to IR with characteristics of mitotic catastrophe, senescence, lipid peroxidation, and caspase activity. Iron chelators (but not Ferrostatin-1 or vitamin E) could prevent the formation of lipid peroxides and cell death induced by IR, suggesting a crucial role of iron-dependent cell death during high-dose irradiation. We also show that in K-Ras-mutated cells, IR can induce morphological features reminiscent of methuosis, a cell death modality that has been recently described following H-Ras or K-Ras mutation overexpression.

Damage and fracture law of coal samples with different joint angles and their characterisation by acoustic emission

The application of the acoustic emission (AE) and damage theory to the evaluation of coal rock stability requires a clear comprehension of the influence of joints. The mechanical and AE response characteristics and damage evolution characteristics of samples with different joint angles were analysed through uniaxial compression tests. The results show that the angle between the loading principal stress and joint surface considerably influences the mechanical characteristics of samples and the damage degree characterised by the AE. However, the existing models of AE damage characterisation do not fully reflect the damage characteristics of samples with different loading principal stresses and joint surface angles. In this paper, the improved damage model characterised by the AE count accumulation is proposed. The model has clear physical and mechanical bases and can effectively characterise the damage catastrophe characteristics of the samples with different joint angles. It also has an important application value in coal and rock dynamic disaster monitoring and early warning, damage detection and other projects.

Non-linear characteristics in switching intention to use a docked bike-sharing system

Bike-sharing systems have been popular in addressing the “last mile” problem in public transit. However, service providers have found challenges when soliciting travellers to shift from their private vehicles: more stations do not always mean higher switching by private vehicle users. Considering the possible non-linear relationship between service provision and intention to use, this study utilises the cusp catastrophe model to analyse travellers’ intentions to use a bike-sharing system. The proposed model employs usage intention as the state variable, while switching barriers and accessibility are used as splitting factor and normal factor, respectively. This study measures participants’ usage intentions for two trip purposes and nine accessibility scenarios for CityBike, a public docked bike-sharing system in an Asian city where the majority of travellers use private vehicles. The results support a non-linear relationship between service provision and intention to use with the catastrophe characteristics including divergence, sudden transitions, and hysteresis of usage intention. In particular, travellers with higher switching barriers show a sudden, yet delayed response to improvements in a service only when it reaches a threshold in accessibility (e.g., 100 m away from the station and the lead time for rental within 3 min), whereas those with low switching barriers respond immediately to service improvements. We discuss marketing implications in facilitating switching to docked bike-sharing services among different segments. This research has made theoretical and empirical contributions, by supporting the non-linearity between accessibility and usage intention, along with diverse marketing materials and service provision catering to different usage occasions.

Linkage-based device for creep testing of coal rock.

The creep properties of coal rock have been extensively investigated under conventional uniaxial stress conditions, whereas few studies have considered its characteristics or the process of seepage under triaxial stress. This study proposes and verifies a linkage-based creep test device for coal rock to study its creep characteristics under triaxial stress. The deformation, pressure, and signals of acoustic emission under triaxial stress were measured by using a specially designed data measurement system. The experimental device uses the connecting rod loading mechanism for continuous constant pressure loading. Through theoretical calculations and finite element analysis, the authors show that the strength and stiffness of the device satisfy the requirements of a maximum load of 300 kN. A creep test was carried out to verify the operation of the proposed device and analyze the creep characteristics of sandstone under different confining pressures. The results show that the device can analyze the catastrophic characteristics of sandstone, and this proves its validity and reliability in terms of monitoring the continuous pressure or constant pressure of sandstone during creeping. The device provides a new method to study the creep properties of coal rock under different stresses and seepage conditions.

Mitotic catastrophe and p53-dependent senescence induction in T-cell malignancies exposed to nonlethal dosage of GL-V9.

Mitotic catastrophe of cancer cells induced by drugs is characterized by low dosage and low toxicity, representing a significant advantage in the cancer treatment. Effective therapeutic options are limited for T-cell malignancies patients who are still treated by high-dose multiagent chemotherapy, potentially followed by hematopoietic stem cell transplantation, highlighting the urgency for identification of more effective anti-T-cell malignancies drugs. The use of antineoplastic drugs which induced tumor cell mitotic catastrophe would be a new strategy for cancer therapy. Nevertheless, there is still no effective mitotic catastrophe agent in T-cell malignancies. Our study showed that nonlethal dosage (ND) of GL-V9 (5-hydroxy-8-methoxy-2-phenyl-7-(4-(pyrrolidin-1-yl) butoxy) 4 H-chromen-4-one) (2µM), a potential anticancer drug, not only attenuated cell growth and survival, but also arrested the cell cycle in G2/M phase and induced multipolar spindles, nuclear alterations (micronucleation and multinucleation), which are the most prominent morphological characteristics of mitotic catastrophe, in T-cell malignancies cell lines including Jurkat, HuT-102, and HuT-78. Moreover, ND GL-V9 could trigger DNA damage, and significantly influence several mitosis-associated proteins. Besides, results showed that ND GL-V9 increased the activity of senescence-associated β-galactosidase (SA-β-Gal) following the induction of mitotic catastrophe in Jurkat and HuT-102 cells with intact p53, while causing apoptosis in p53-deficient HuT-78 cells. We concluded that the anti-T-cell malignancies effects of ND GL-V9 and clarified the precise regulation in the process of mitosis under the action of GL-V9 in T-cell malignancies. Our data provided new evidence for the study of T-cell malignancies treatment associated with mitotic catastrophe and cellular senescence induction.

Numerical Calculation of Instability of Tunnel Surrounding Rock Based on Elastic Hole Theory

The instability and unloading of surrounding rock structure in tunnel under TBM construction condition can easily induce large-scale rock caving in heading face, which seriously restricts safe and efficient tunneling. Aiming at the instability problem of surrounding rock structure of tunnel constructed by TBM, four types of slope induced by excavation disturbance are summarized systematically based on elastic hole theory, and the instability mechanism of roof structure and surrounding rock of tunnel is analyzed; the instability mechanism and catastrophic characteristics of surrounding rock structure of tunnel are analyzed by FLAC3D finite element numerical calculation software, and the roof transportation of tunnel after supporting is carried out. The amount of movement is greatly reduced and the overall failure degree of overlying strata is slowed down. The results show that the roof is prone to structural instability under the influence of tunneling disturbance. Tunnel support can effectively hinder the movement of overlying rock roof and floor, alleviate the probability of rock mass catastrophe, effectively control the dynamic disasters, and achieve safe tunneling.

Correlation between catastrophizing and pain in knee osteoarthritis patients

Purpose: Osteoarthritis of the knee often leads to frequent and intense pain. Psychosocial factors influence the intensity which chronic pain is expressed. Catastrophizing has been broadly conceived as an exaggerated negative "mental set" brought to bear during painful experiences. Cognitive distortions and catastrophic thoughts contribute to the increase in pain intensity. The aim of this study was to correlate catastrophizing and pain in patients with knee osteoarthritis. Methods: Patients with knee osteoarthritis responded to the visual analogue scale (VAS), Western Ontario and McMaster Universities Osteoarthritis index (WOMAC), Short Form-36 (SF-36) quality of life questionnaire and Pain-Related Self-Statements Scale(PRSS). Data were analyzed with independent t-student test or the Mann-Whitney test. Then, the PRSS catastrophic scale was compared to others through Spearman Correlation, obtaining direction and strength of the correlation. Results: A total of 53 patients,(64.2% female), with a mean age of 64.3 years and a mean BMI of 30.3 responded all questionnaires. Woman presented with higher values on PRSS (p=0.012), VAS (p=0.016) and WOMAC score (p=0.026) in relation to males, as well as greater SF-36 dysfunction in physical functioning (p=0.017), bodily pain (p=0.002), general health perceptions (p=0.028), vitality (p=0.000), role-emotional (0.031) and mental health (p=0.001) domains. Age or BMI did not influence the central tendency and dispersion of pain, total Womac, SF-36 or catastrophizing scale.. There was a strong positive correlation between PRSS and VAS (ρ=0.615; p=0.000) and between PRSS and WOMAC (ρ=0.682; p=0.000). The multivariate analysis resulted in a statistically significant model, in which the WOMAC scale was a predictor of the PRSS scale (p<0.001). Conclusions: Individuals with higher catastrophizing characteristics present more pain, worse function and worse quality of life according to the scales used. Female patients had higher catastrophizin, pain and worse function in relation to males.Table IEndpoint analysis according to genderGenderp-valueMale (n = 19)Female (n = 34)Visual Analogue PainScale (VAS)b55 (44–81)80 (68–84.25)0.016‡WOMAC Paina8.84 ± 3.6311.79 ± 4.320.015† Stiffnessb5 (3–6)6 (3.75–6)0.402‡ Functionb36 (31–48)46 (37–56.25)0.055‡ TOTALb52 (45–65)60.5 (52.75–76.25)0.026‡SF-36 Physical Functioningb30 (20–60)15 (5–30)0.017‡ Role-physicalb0 (0–0)0 (0–25)0.447‡ Bodily painb41 (30–61)22 (7.5–32)0.002‡ General health perceptionsa65.11 ± 23.4948.59 ± 26.580.028† Vitalitya66.84 ± 21.2340.29 ± 20.710.000† Social functioningb75 (37–87)50 (25–75)0.053‡ Role-emotionalb33 (0–100)0 (0–33)0.031‡ Mental Healtha72.84 ± 21.4848.71 ± 23.420.001†PRSS PRSSb16 (9–21)32.5 (11.5–42.25)0.012‡ Adjusted (0-5)b1.77 (1–2.33)3.61 (1.28–4.69)0.012‡a Values expressed as mean ± standard deviation; b Values expressed as median; † Student-t test; ‡ Mann-Whitney. Open table in a new tab Table IIAnalysis of PRSS scale correlation to visual pain scale, Womac and SF-36Spearman correlationCoeficient (ρ)∗ρ = rho.p-valueVisual Analogue Pain Scale (VAS)0.6150.000WOMAC Pain0.6560.000 Stiffness0.6770.000 Function0.6120.000 TOTAL0.6820.000SF-36 Physical Functioning−0.4580.001 Role-physical−0.3670.007 Bodily pain−0.5030.000 General health perceptions−0.5170.000 Vitality−0.5600.000 Social functioning−0.4610.001 Role-emotional−0.4820.000 Mental Health−0.4790.000∗ ρ = rho. Open table in a new tab a Values expressed as mean ± standard deviation; b Values expressed as median; † Student-t test; ‡ Mann-Whitney.

Effects of pain catastrophizing and anxiety on analgesic use after surgical removal of impacted mandibular third molars.

BackgroundIn dentistry, pain is a factor that negatively affects treatments and drug use. The aim of this study was to evaluate the correlations of the postoperative analgesic use with pain catastrophizing and anxiety in patients who underwent removal of an impacted mandibular third molar.MethodsWe recruited 92 patients who underwent the extraction of impacted mandibular third molar. In this study, the Pederson index was used to preoperatively determine the difficulty of surgical extraction. Patients were asked to note the number of analgesics used for 7 postoperative days. Patients were divided into two groups based on the Pain Catastrophizing Scale: low and high score groups. State-Trait Anxiety Inventory-trait and State-Trait Anxiety Inventory-state questionnaires were used to determine the anxiety levels of the patients. The obtained data were examined to evaluate the correlations of pain catastrophizing and anxiety with the postoperative analgesic use.ResultsIn this study, 92 patients, including 60 women and 32 men, were recruited. The analgesic use was higher in women than in men but with no significant difference (P > 0.05). Pain Catastrophizing Scale scores were higher in women than in men but with no significant difference (P > 0.05). The analgesic use was higher in patients with high pain catastrophizing than in those with low pain catastrophizing but with no significant difference (P > 0.05). State-Trait Anxiety Inventory-trait scores were higher in women than in men but with no significant difference. However, state-Trait Anxiety Inventory-state scores were significantly higher in women than in men (P < 0.05).ConclusionThe postoperative analgesic use may be higher in patients who catastrophize pain than in others. Knowing the patient's catastrophic characteristics preoperatively would contribute to successful pain management and appropriate drug selection.

Priming anti-tumor immunity by radiotherapy: Dying tumor cell-derived DAMPs trigger endothelial cell activation and recruitment of myeloid cells

ABSTRACT The major goal of radiotherapy is the induction of tumor cell death. Additionally, radiotherapy can function as in situ cancer vaccination by exposing tumor antigens and providing adjuvants for anti-tumor immune priming. In this regard, the mode of tumor cell death and the repertoire of released damage-associated molecular patterns (DAMPs) are crucial. However, optimal dosing and fractionation of radiotherapy remain controversial. Here, we examined the initial steps of anti-tumor immune priming by different radiation regimens (20 Gy, 4 × 2 Gy, 2 Gy, 0 Gy) with cell lines of triple-negative breast cancer in vitro and in vivo. Previously, we have shown that especially high single doses (20 Gy) induce a delayed type of primary necrosis with characteristics of mitotic catastrophe and plasma membrane disintegration. Now, we provide evidence that protein DAMPs released by these dying cells stimulate sequential recruitment of neutrophils and monocytes in vivo. Key players in this regard appear to be endothelial cells revealing a distinct state of activation upon exposure to supernatants of irradiated tumor cells as characterized by high surface expression of adhesion molecules and production of a discrete cytokine/chemokine pattern. Furthermore, irradiated tumor cell-derived protein DAMPs enforced differentiation and maturation of dendritic cells as hallmarked by upregulation of co-stimulatory molecules and improved T cell-priming. Consistently, a recurring pattern was observed: The strongest effects were detected with 20 Gy-irradiated cells. Obviously, the initial steps of radiotherapy-induced anti-tumor immune priming are preferentially triggered by high single doses – at least in models of triple-negative breast cancer.

Damage characterization model of ceramic coating systems based on energy analysis and bending tests

A quantitative damage model of ceramic coating systems was developed based on their load-displacement curves obtained from three-point bending tests. According to the energy mechanism of damage, the normalized damage rate of such systems can be simply expressed using the load and the tangent slope of their load-displacement curves. The experimental results demonstrated the thickness dependence of fracture and damage. In thin coating systems, tensile failure was found to be predominant and multiple transverse cracks appeared in the coatings. In contrast, thick coating systems showed a predominance of interface shear failure and the occurrence of interface delamination. These observations are consistent with previous experimental results. The damage of the systems displayed catastrophic characteristics when the load tended to reach the failure point, i.e., the damage increased rapidly, and the damage rate displayed a power-law singularity at the failure point. These results are consistent with the damage characteristics predicted using the mathematic model. The damage evolution in the case of interface delamination in the thick coating systems was faster than that for transverse cracking in the thin coatings because of the difference in the degree of damage localization. The present model provides an effective method to elucidate the damage behavior of brittle ceramic coating systems, and hence, it is expected to greatly aid the coating design.

Pricing Zero-Coupon Catastrophe Bonds Using EVT with Doubly Stochastic Poisson Arrivals

The frequency and severity of climate abnormal change displays an irregular upward cycle as global warming intensifies. Therefore, this paper employs a doubly stochastic Poisson process with Black Derman Toy (BDT) intensity to describe the catastrophic characteristics. By using the Property Claim Services (PCS) loss index data from 2001 to 2010 provided by the US Insurance Services Office (ISO), the empirical result reveals that the BDT arrival rate process is superior to the nonhomogeneous Poisson and lognormal intensity process due to its smaller RMSE, MAE, MRPE, and U and larger E and d. Secondly, to depict extreme features of catastrophic risks, this paper adopts the Peak Over Threshold (POT) in extreme value theory (EVT) to characterize the tail characteristics of catastrophic loss distribution. And then the loss distribution is analyzed and assessed using a quantile-quantile (QQ) plot to visually check whether the PCS index observations meet the generalized Pareto distribution (GPD) assumption. Furthermore, this paper derives a pricing formula for zero-coupon catastrophe bonds with a stochastic interest rate environment and aggregate losses generated by a compound doubly stochastic Poisson process under the forward measure. Finally, simulation results verify pricing model predictions and show how catastrophic risks and interest rate risk affect the prices of zero-coupon catastrophe bonds.