Low-risk Regions Research Articles

Diffusive host-pathogen model revisited: Nonlocal infections, incubation period and spatial heterogeneity

We formulate and analyze a general diffusive host-pathogen model with an incubation period and nonlocal infections in a spatially heterogeneous environment. The model system is partially degenerate and the solution map is not compact. We first prove that the solutions of the model exist globally and are ultimately bounded. Next, we define the basic reproduction number R0 as the spectral radius of the sum of two next generation operators corresponding to direct and indirect infection modes, and prove that R0 is decreasing with respect to the incubation period and the diffusion coefficient of infectious hosts under some conditions. Finally, we demonstrate that the model system possesses a global attractor, and explore the global dynamics of the system. Especially, we show that the infection-free steady state is globally asymptotically stable if R0≤1. On the other hand, if R0>1, then the infection will persist and the model system admits at least one positive steady state. For spatial homogeneous system, global asymptotic stability of the positive steady state is proved via Lyapunov functional technique. Numerical simulation is conducted to explore singular perturbation phenomenon when the diffusion coefficients approach zero. We observe that the diffusion will not only spread the infection to the low-risk region, but it may also increase the infection level in the high-risk region.

Implications of updated epidemiological characteristics from heart diseases in China

Implications of updated epidemiological characteristics from heart diseases in China

Immunotyping of lymphocytes in the gastric mucosa of patients infected by H. pylori in two regions with contrast in the risk of developing gastric cancer

To compare the immune response in gas tric mucosa of H. pylori infected patients in two regions comparing the risk of developing gastric can cer. 71 participants with symptoms of dyspepsia were included. The samples for biopsies were collected from different regions of the gastric mucosa; the identification of H. pylori was carried out by culture and polymerase chain reaction (PCR) of the ureA gene. For the characteri zation of the histopathological alterations and the immunophenotyping of lymphocytes, anti-human mouse monoclonal antibodies specific for each antigen were used: T lymphocytes: CD3 and CD8; B lymphocytes: CD20; Natural Killer Cells: CD56; Macrophages: CD68. The prevalence of H. pylori was 83.1%, the predominant types of gastritis were chronic gastritis and multifocal atrophic gastritis with intestinal metaplasia (63.4% and 22.5%, respectively). The cellular response was charac terized mainly by polymorphonuclear lymphocytes and positive anti-CD8 reactivity both in stroma and epithelium. Multifocal atrophic gastritis was more prevalent in the high-risk region for gastric cancer (GC) while non-atrophic gastritis and the expression of CD3 and CD8 antigens in the foveolar epithelium was higher in the low-risk region.

Selective treatment de-intensification with reduced-dose radiation and omitted concurrent chemotherapy guided by response to induction chemotherapy in HPV-associated oropharyngeal squamous cell carcinoma: A single-arm, phase II trial (IChoice-01).

e18069 Background: De-intensification in chemoradiation provides a strategy to optimize the trade-off between treatment efficacy and toxicities in HPV-associated oropharyngeal squamous cell carcinoma (OPSCC). However, the failure of RTOG 1016 and De-ESCALaTE indicated the pitfall of de-escalation in an unselective population and the importance of patient selection for future study design. Induction chemotherapy (IC), as a potential biomarker, has been adopted in several trials to screen candidates for de-intensified treatment based on its tumor response. In present trial, we investigated the feasibility of selectively de-intensified chemoradiotherapy by reducing radiation dose and omitting concurrent chemotherapy guided by response to IC. Methods: From Jan 2019 to July 2021, 48 patients with p16 positive OPSCC, T1-2/N1-3M0 (excluding T1N1M0 patients with single and≤3cm lymph node) or T3-4N0-3M0 according to the UICC/AJCC 8th staging system were enrolled. All of them received two cycles of IC with cisplatin and docetaxel. Those with major response to IC (defined as cCR or ≥50% cPR of both primary site and lymph nodes) received de-intensified treatment with intensity modulated radiation therapy (IMRT) alone with 60Gy to high-risk and 54Gy to low-risk regions (Di cohort). Those with less than major response were given standard chemoradiotherapy with 70Gy to both primary tumor and positive lymph nodes, 63Gy to high-risk and 56Gy to low-risk regions, concurrently with two cycles of cisplatin (St cohort). The primary endpoint was 2-year progression-free survival (PFS). Results: 26/48 (54.2%) patients entered Di cohort while other 22/48 (45.8%) patients entered St cohort. With a median follow-up time of 20.5 months (2.8-36.7months), 3 deaths (1 in Di cohort and 2 in St cohort), 5 loco-regional recurrence (1 in Di cohort and 4 in St cohort) and 6 distant metastases (1 in Di cohort and 5 in St cohort) were documented. The 2-year PFS rates for Di and St cohort were 100% and 60.0% (P = 0.002) with overall survival (OS) rates of 100% and 83.1% (P = 0.062), loco-regional recurrence-free survival (LRFS) rates of 100% and 77.0% (P = 0.035), metastasis-free survival (MFS) rates of 100% and 66.8% (P = 0.011), respectively. Conclusions: For major responders to IC, reduced-dose radiation with omitted concurrent chemotherapy yielded good survival results. In comparison, patients resistant to IC showed poor prognosis even under standard-dose chemoradiotherapy, calling for treatment intensification or development of novel therapeutic agents. Selective de-intensification of chemoradiation guided by response to IC is promising in HPV-associated OPSCC and warrants further evaluation in future studies. Clinical trial information: NCT04012502.

Hearing Loss After Cisplatin-based Chemoradiotherapy for Locally Advanced Head and Neck Cancer: A Prospective Single-institution Study.

A single-institution prospective study was conducted to evaluate hearing loss rate after intensity modulated radiotherapy with concomitant cisplatin-based chemotherapy (CRT) for locally advanced head and neck cancer and identify cochlear dosimetric parameters associated with hearing loss risk. Hearing assessment, patients' characteristics, tumor-related variables, and cochlear quantitative dosimetric factors for adults with locally advanced head and neck cancer treated with CRT were prospectively collected. Each patient repeated audiometry at baseline (pre-CRT), 1 month after CRT, and then every 3 to 6 months. For each cochlea minimum dose (Dmin), mean dose (Dmean), and maximum dose (Dmax) were extracted from treatment plans. Logistic analysis was used for multivariate modeling. The relation between cochlear dosimetric factors and significant hearing loss was also analyzed with receiver operating characteristic (ROC) curves. Between January 2016 and December 2018, 35 patients (70 cochleae) were included. Most patients (n=29; 82.9%) had primary cancer in a low-risk region (oral cavity, oropharynx, larynx). All patients completed the programmed CRT. During follow-up, significant hearing loss was recorded in 13 cases (37.1%). The ROC areas for significant hearing loss in relation to Dmin, Dmean, and Dmax were 0.70, 0.66, and 0.66, respectively. A dose-dependent relationship was noted between cochlear Dmin and significant hearing loss. Dmin <14.4 Gy is associated with reduced rates of significant hearing loss after concomitant cisplatin-based CRT in patients with locally advanced head and neck cancer.

Assessment of Pollution and Identification of Sources of heavy Metals, and Radionuclides Contamination in Sand along the Southern part of the Cameroonian coast (South-West, Africa)

Sandy sediments collected along the southern part of the Cameroonian coast have been analyzed geochemically by ICP MS methods to investigate the distribution characteristics, contamination levels and related ecological risks. In these sediments, the concentration (mg/kg) of selected elements are in order Fe &gt; Mn &gt; Cr &gt; V &gt; Th &gt; Ni &gt; U &gt; Co. Indices of pollution such as index of geoaccumulation, where values of all elements in the sediments were &lt; 0, except Th in the sediments station of Yoyo II, and Cr in sediment of all stations were Igeo &gt; 0. Contamination factor shows that the station of Yoyo II has values of CF &lt; 1, such as Fe, V, Ni and Co. while Uranium, Th and Mn values vary from 1 to 3 and 3 to 6, and for Cr values of CF &gt; 6. However, Kribi and Campo stations show that all the elements have values of CF &lt; 1, except Cr which has values of CF &gt; 6. The degree of contamination values ranges between (9.48 – 37.13) for the station of Yoyo II, (8.84 – 17.62) for Kribi station, and (6.52 – 13.56) for Campo station. The pollution loading index values at all sampling stations are lower than 1. The potential ecological risk (Er and RI), indicates that this coastal area is a low risk region. Pearson correlation, cluster analysis and principal component analysis supported that heavy metals (Fe, Mn, Cr, V, Ni and Co) have common human influences while radionuclides (Th and U) have a natural source. The presence of human activities such as domestic waste, intensive farming and the processing of industrial products could be potential sources of anthropogenic environmental pollution, thereby threatening the environmental concerns of the entire study area.

Performance of Coronary Artery Calcium Testing in Patients With Severe Psoriasis: Risk Assessment and Reclassification Potential in a Low Cardiovascular Risk Population

BackgroundPatients with severe psoriasis have an increased cardiovascular (CV) risk and prevalence of subclinical coronary artery disease (CAD). Coronary artery calcium (CAC) testing can detect subclinical CAD and improve cardiovascular risk assessment beyond clinical scores. ObjectivesEvaluate the presence and magnitude of subclinical CAD determined by CAC score among the different ESC/EAS CV risk categories, as well as the potential for risk reclassification, in patients with severe psoriasis from a low CV risk population. MethodsUnicentric cross-sectional study in 111 patients with severe chronic plaque psoriasis from a low CV risk population in the Mediterranean region. Patients were classified into four CV risk categories according to the ESC/EAS guideline recommendations and HeartScore/SCORE calibrated charts. Patients underwent coronary computed tomography to determine their CAC scores. Patients in the moderate-risk category with a CAC score of ≥100 were considered to be reclassified as recommended by the 2019 ESC/EAS guidelines. Reclassification was also considered for patients in the low-risk category with a CAC score>0. ResultsPresence of subclinical CAD was detected in 46 (41.4%) patients. These accounted for 86.2% of patients in high/very-high-risk categories and 25.6% of patients in non-high-risk categories. Fourteen (17.1%) of the patients in non-high-risk categories were reclassifiable due to their CAC score. This percentage was higher (25%) when considering the moderate-risk category alone and lower (13.8%) in the low-risk category. Age was the only variable associated with presence of subclinical CAD and reclassification. ConclusionsOver 40% of patients with severe psoriasis from a low-risk region and up to 25% of those in non-high-risk categories have subclinical CAD. CAC appears to be useful for reclassification purposes in CV risk assessment of patients with severe psoriasis. Further research is required to elucidate how CAC could be implemented in everyday practice at outpatient dermatology clinics dedicated to severe psoriasis.

Psychological Impact of COVID-19 on Ophthalmologists in Iran.

PurposeTo identify the psychological impact of coronavirus disease on ophthalmologists practicing in Iran between August and December 2020.MethodsIn this cross-sectional online survey, a standard Patient Health Questionnaire- 9 (PHQ- 9) was completed by 228 ophthalmologists who were practicing in Iran. The PHQ- 9 questionnaire was revised by adding two additional questions specifically applicable for the assessment of the psychological impact of coronavirus disease on the Iranian ophthalmologists. An organized classification regarding the assessment of different depression severities identified as no (0–4), mild (5–9), moderate (10–14), or severe (15–21) was then considered for data analysis.ResultsThe mean age of our participants was 49.0 15.61 years and the majority of them (67.1%) were male. Depression was discovered in 73.68% (n = 168) with different severities ranging from mild (n = 61, 26.75%), moderate (n = 63, 27.63%), and severe (n = 44, 19.3%). It was found that participants with depression were older as compared to those without depression (P = 0.038). Higher percentages of severe depression were noticed in the high-risk regions contaminated with corona virus as compared to the other low-risk regions (P = 0.003). Based on multivariable models, we determined that ophthalmologists who were somewhat concerned about their training/ profession (OR: 0.240; 95% CI: 0.086–0.672; P = 0.007) and those with no concerns about their income had lower association with depression (OR: 0.065; 95% CI: 0.005–0.91; P = 0.042).ConclusionHigh prevalence of depression was observed among older aged Iranian ophthalmologists living in high-risk contaminated regions who possessed serious concerns with respect to their training/profession and income. It is recommended that the health policymakers of Iran pay more attention to the ophthalmologists who experience the aforementioned factors.

SIS reaction–diffusion model with risk-induced dispersal under free boundary

A spatial susceptible–infected–susceptible epidemic model with a free boundary, where infected individuals disperse non-uniformly, is investigated in this study. Spatial heterogeneity and movement of individuals are essential factors that affect pandemics and the eradication of infectious diseases. Our goal is to investigate the effect of a dispersal strategy for infected individuals, known as risk-induced dispersal (RID), which represents the motility of infected individuals induced by risk depending on whether they are in a high- or a low-risk region. We first construct the basic reproduction number and then understand the manner in which a nonuniform movement of infected individuals affects the spreading–vanishing dichotomy of a disease in a one-dimensional domain. We conclude that even though the infected individuals reside in a high-risk initial domain, the disease can be eradicated from the region if the infected individuals move with a high sensitivity of RID as they disperse. Finally, we demonstrate our results via simulations for a one-dimensional case.

Changes in Landscape Pattern and an Ecological Risk Assessment of the Changshagongma Wetland Nature Reserve

The Changshagongma wetlands is the Chinese National Nature Reserve were listed as a Ramsar Wetland of International Importance in 2018. Here, we examined four periods (1992, 2002, 2013, and 2020) of remote sensing image data to analyze the changes in wetland landscape patterns and the ecological risk in Changshagongma Wetland Nature Reserve over the past 30 years. The results showed that wetlands account for approximately 30% of the study area, and swamp meadows were the main type of wetland, accounting for approximately 95% of the total wetland area. In terms of landscape patterns, wetland fragmentation declined, wetland patch shapes became less complicated, and spatial connectivity increased. The landscape fragmentation of non-wetland alpine meadows was reduced. The patches of sandy grasslands tended to be regular, and their spatial connectivity was reduced. The wetland regions of high ecological risk are concentrated in the central and southern parts of the Changshagongma Wetland Nature Reserve. Low-risk regions are mainly concentrated in the contiguous swamp meadows in the northwest and wetlands in the southwest. From 1992 to 2020, the level of ecological risk of the Changshagongma Wetland Nature Reserve showed a “∧”-shaped trend, with the highest risk in 2002 and the lowest risk in 2020. Among the selected indicators, climate conditions constituted the main factor affecting the ecological risk of the Changshagongma Wetland Nature Reserve, followed by topographical conditions, and human activities were the least influential. Over the past 30 years, the temperature and precipitation in the study area increased significantly. The climate in the study area can be roughly divided into two periods bounding 2002, and the climate has been changing from cold and dry to warm and wet. The ecological environment of the study area is affected by natural and human activities. Cold and dry climatic conditions and uncontrolled grazing accelerate the destruction of the wetland ecological environment, and warm and wet climatic conditions and ecological conservation policies are conducive to the ecological restoration of wetlands. In general, the wetland landscape structure in the study area has become less complex, landscape heterogeneity has decreased, and ecological quality has improved.

Spatial Zoning of Dry-Hot Wind Disasters in Shandong Province

As a major agricultural province of China, Shandong province has long ranked first in agricultural growth value among all of the provinces; at the same time, it is also the province that is most affected by dry-hot wind. Therefore, it is of great significance to study the spatial zoning of the risks of dry-hot wind in this province. Based on meteorological, slope, and altitude data, and the principle of disaster risk assessment, this study uses a weighted comprehensive evaluation method, analytic hierarchy process, and ARC-GIS spatial analysis to study the spatial zoning of the risks of dry-hot wind in Shandong province. The results show that the high-risk regions of dry-hot wind are concentrated in the north-central portion of the province, the medium-risk regions are in the peripheral areas, and the low-risk regions are located mainly in the west, southwest, and east. Exposure of disaster-bearing bodies is high in the south and low in the north, while vulnerability to disaster-bearing bodies is high in the west and low in the east. The more developed areas in the east show high disaster prevention and mitigation capability, whereas this is weak in the west. In summary, dry-hot wind risk in Shandong province varies significantly by area. The medium- and high-risk areas are mainly in the west and central portions of the province.

Swallowing sparing intensity modulated radiotherapy versus standard parotid sparing intensity-modulated radiotherapy for treatment of head and neck cancer: a randomized clinical trial

Background Dysphagia is a distressing symptom during and after radiotherapy treatment in head and neck cancer (HNC) patients. The objective of this prospective study was to investigate whether swallowing sparing intensity modulated radiotherapy (SW-IMRT) reduces the occurrence of swallowing dysfunction compared to the standard IMRT (ST-IMRT). Methods We randomized, planned, and treated patients with HNC who needed whole neck irradiation using the simultaneous integrated boost (SIB) IMRT technique. Doses of 70, 60, and 54 Gy (over 33 daily fractions) were prescribed to the primary tumor, high-risk and low-risk regions, respectively. The postoperative cases received 60 and 54 Gy (over 30 daily fractions) to the high-risk planning target volume (PTV) and low-risk PTV. We contoured organs at risk related to swallowing dysfunction (SWOARs) in all cases. In the ST-IMRT group, parotids only were spared. In the SW-IMRT group, parotids and SWOARs outside the high-risk PTV were spared. Assessment of dysphagia included clinical and instrumental evaluation. Results One hundred forty-six patients ended their radiotherapy treatment. Dose distribution showed comparable PTV coverage and no difference in parotid glands sparing between the two groups. SWOARs dose reduction with SW-IMRT differs according to tumor location and its overlap with SWOARs. Using different assessment methods, SW-IMRT was associated with a lower occurrence of dysphagia up to one year after treatment. There was no difference between the two groups regarding acute dysphagia (p = 0.262), overall survival (p = 0.811), and disease-free survival (p = 0.876). Conclusion SW-IMRT is significantly better than ST-IMRT regarding a physician-rated and objective assessment of swallowing dysfunction at short- and long-term post-treatment follow-up.

The control of moldy risk during rice storage based on multivariate linear regression analysis and random forest algorithm

Clarifying the mechanism of fungi growth is of great significance for maintaining the quality during grain storage. Among the factors that affect the growth of fungi spores, the most important factors are temperature, moisture content and storage time. Therefore, through this study, a multivariate linear regression model among several important factors, such as the spore number and ambient temperature, rice moisture content and storage days, were developed based on the experimental data. In order to build a more accurate model, we introduce a random forest algorithm into the fungal spore prediction during grain storage. The established regression models can be used to predict the spore number under different ambient temperature, rice moisture content and storage days during the storage process. For the random forest model, it could control the predicted value to be of the same order of magnitude as the actual value for 99% of the original data, which have a high accuracy to predict the spore number during the storage process. Furthermore, we plot the prediction surface graph to help practitioners to control the storage environment within the conditions in the low risk region.

Implications of the 2021 ESC cardiovascular risk classification among 283,000 European immigrants living in a low-risk region: a population-based analysis in Catalonia.

The ESC recently classified European countries into 4 cardiovascular risk regions. However, whether Europeans from higher-risk countries living in lower-risk regions may benefit from intensive cardiovascular prevention efforts is unknown. We described the burden of risk factors and cardiovascular disease (CVD) among European-born immigrants living in Catalonia, a low-risk region. A retrospective cohort study of 5.6 million adults of European origin living in Catalonia in 2019, including 282,789 European-born immigrants, was performed. We used the regionwide healthcare database and classified participants into 5 groups: low-, moderate-, high-, and very high-risk, and local-born. Age-standardized prevalence was estimated as of December 31st, 2019 and incidence was computed during 2019 among at-risk individuals. The very high-risk group was the largest immigrant group (N = 136,910; 48.4%), while the high-risk group was the smallest (N = 15,739; 5.6%). These two had the highest burden of coronary heart disease across all groups evaluated, in both men and women. The very high-risk group also had the highest prevalence of hypertension and obesity at young-to-middle age, and the burden of risk factors newly diagnosed during 2019 was highest in high- and very high-risk participants. The mean age at first diagnosis of risk factors and CVD was lower in these groups. In Catalonia, residents born in high- and very-high-risk European countries are at increased risk of coronary heart disease and newly diagnosed risk factors. Low-risk European countries may consider tailored prevention efforts, early screening of risk factors, and adequate healthcare resource planning to better address the health needs of men and women from higher-risk countries.

A Non-Parametric Analysis to Estimate Dose Distributions Associated With High-Risk vs. Low-Risk of Death in RTOG 0617

<h3>Purpose/Objective(s)</h3> Analyses of locally-advanced non-small cell lung cancer (LA-NSCLC) series have identified radiation dose to the cardio-pulmonary system as a new key detriment for risk of death. However, spatial dose patterns are typically represented as one-dimensional dose metrics of pre-defined segmented structures. Here we introduce the use of a recently developed non-parametric approach based on an extended form of optimal mass transport (OMT), called unbalanced OMT distance. Thoracic dose distributions were ranked in relation to risk of death within RTOG 0617. This agnostic approach preserves the spatial dose information without pre-selection of specific thoracic sub-regions or normalization. <h3>Materials/Methods</h3> The 409 patients with evaluable data (CTs, dose, structures and overall survival status) were retrieved from The Cancer Imaging Archive. Patients were censored at 60 months. Data was split into a 70% training and a 30% validation data (n = 286 and 123). Dose distributions were deformably registered to randomly selected reference patients using multi-step B spline. The unbalanced OMT distance measures dose spread pattern and total amount of dose differences among patients. Using a newly proposed approximation of the unbalanced OMT distance via vector-valued OMT, the highly complicated distances between pairs of dose distributions were computed efficiently. The OMT distances were translated into risk scores represented by <b>C</b>-indices: small distances (low <b>C</b>-indices) represent high-risk; large distances (high <b>C</b>-indices) represent low-risk. Risk status in the validation data was measured as distances to the training reference patients. Lastly, two sub-regions were deduced: One high-risk region based on the 50 riskiest patients (overlap of at least 80% of distributions including the highest 80% dose relative to max dose) and one low-risk region based on the 50 least risky patients. The locations of the sub-regions were qualitatively compared to those of eight deep learning auto-segmented cardio-pulmonary substructures (aorta, atria, inferior and superior vena cava (SVC), pulmonary artery (PA), ventricles). <h3>Results</h3> The highest risk of death was identified in a region overlapping with the base of the heart, including the ascending aorta, PA and the superior part of the left atrium. In contrast, the ‘safe' distributions associated with the lowest risk of death mostly avoided all cardio-pulmonary substructures with the exception of the SVC and right PA. <h3>Conclusion</h3> This non-parametric approach identified specific high-risk and low-risk regions associated with death in RTOG 0617. While there was no one-to-one correspondence between the identified high-risk region and the segmented cardio-pulmonary structures, this region focused on the base of the heart. The identified regions may direct further work on elucidating mechanisms and generalizability.

Would COVID-19 vaccination willingness increase if mobile technologies prohibit unvaccinated individuals from public spaces? A nationwide discrete choice experiment from China

BackgroundAchieving COVID-19 community protection (aka, herd immunity) in China may be challenging because many individuals remain unsure or are unwilling to be vaccinated. One potential means to increase COVID-19 vaccine uptake is to essentially mandate vaccination by using existing mobile technologies that can prohibit unvaccinated individuals from certain public spaces. The “Health Code” is a ubiquitous mobile phone app in China that regulates freedom of travel based on individuals’ predicted risk of exposure to SARS-CoV-2. Green-colored codes indicate ability to travel unrestricted in low-risk regions; yellow-colored codes indicate prohibition from major public spaces and modes of public transportation. We examined the effects of a “Health Code”-based vaccine mandate on willingness to vaccinate for COVID-19 in China. MethodsIn August 2020, an online discrete choice experiment (DCE) was conducted among adults living in China. Participants completed up to six DCE choice sets, each containing two hypothetical COVID-19 vaccination scenario choices and a “do not vaccinate” choice. Half of the choice sets had a “Health Code” attribute that associated the “do not vaccinate” choice with a yellow Health Code implying restricted travel. Weighted, mixed effects multinomial logit regression was used to estimate preference utilities and predicted choice probabilities. ResultsOverall, 873 participants completed 4317 choice sets. Most participants attained at least college-level education (90.9%). 29.8% of participants were identified as vaccine hesitators (defined as being unsure or unwilling to receive a COVID-19 vaccination). With and without the “Health Code”-based vaccine mandate, there was an 8.6% (85% CI: 6.4% − 10.92%) and 17.3% (85% CI:13.1% − 21.6%) respective predicted probability that vaccine hesitators would choose “do not vaccinate” over a common vaccination scenario currently in China (i.e., free, domestic vaccine, 80% effectiveness, 10% probability of fever side-effects, administered in a large hospital, two doses). Corresponding predicted probabilities for people who did not express vaccine hesitancy was 0.3% (93% CI: 0.0% − 14.3%) and 3.5% (93% CI:2.3% − 4.8%). The “Health Code”-based mandate significantly increased willingness to vaccinate when vaccine efficacy was greater than 60%. ConclusionAmong vaccine hesitators with higher educational attainment, willingness to vaccinate for COVID-19 appears to increase if mobile technology-based vaccine mandates prohibit unvaccinated individuals from public spaces and public transportation. However, such mandates may not increase willingness if perceived vaccine efficacy is low.

Threshold dynamics of a nonlocal and delayed cholera model in a spatially heterogeneous environment.

A nonlocal and delayed cholera model with two transmission mechanisms in a spatially heterogeneous environment is derived. We introduce two basic reproduction numbers, one is for the bacterium in the environment and the other is for the cholera disease in the host population. If the basic reproduction number for the cholera bacterium in the environment is strictly less than one and the basic reproduction number of infection is no more than one, we prove globally asymptotically stability of the infection-free steady state. Otherwise, the infection will persist and there exists at least one endemic steady state. For the special homogeneous case, the endemic steady state is actually unique and globally asymptotically stable. Under some conditions, the basic reproduction number of infection is strictly decreasing with respect to the diffusion coefficients of cholera bacteria and infectious hosts. When these conditions are violated, numerical simulation suggests that spatial diffusion may not only spread the infection from high-risk region to low-risk region, but also increase the infection level in high-risk region.

Psychological Status in the First-Line Medical Staff Fighting Against COVID-19 in Sichuan (Low-Risk Regions): A Multicenter Cross-Sectional Study

Background: The outbreak of 2019 coronavirus disease (COVID-19) in the world has brought great challenges to Medical system. Medical Staff are facing nonnegligible psychological pressure. The psychological status of medical staff in high-risk regions is widely concerned, but there are few studies in low-risk regions. The study focuses on the psychological status of medical staff and influencing factor during COVID-19 epidemic in low-risk regions. Methods: An online questionnaire survey was conducted for 839 medical staff of several hospitals in Sichuan Province from Feb.4 2020 to Feb.25 2020. The questionnaires include self designed questionnaire, Symptom Checklist 90(SCL-90), Simplified Coping Style Questionnaire (SCSQ) and social Support Rating Scale (SSRS). We did single factor analysis on various factors first, then doing multi factor analysis to get the influencing factors of abnormal psychological status. Results: Out of the first-line medical staff who participated in the survey, 149(17.8%) screened abnormal psychological status, (15.3%) for physical discomfort, (14.5%) for depression, (12.2%) for fear and (16.9%) for hostility such as irritation, fatigued, etc. Participants who had insomnia, contact history of COVID-19 patients, negative coping style, low social support were more likely to be psychological abnormality. After adjusting for gender, age and education, it was found that insomnia (OR 4.58, 95% CI 3.06–6.87, p = 0.000), negative coping style (OR 1.14, 95% CI 1.08–1.20, p = 0.000), are risk factors of abnormal psychological status. Meanwhile, positive coping style (OR 0.93, 95% CI 0.90–0.97, p = 0.000), good subjective support (OR 0.85, 95% CI 0.74–0.96, p = 0.014) and high utilization of support (OR 0.86, 95% CI 0.76–0.97, p = 0.015) are protective factors of psychological status in the first-line medical staff. Conclusions: The first-line anti-epidemic medical staffs in low-risk regions have high rate of abnormal psychological status, especially those with insomnia, low social support and negative coping style. Governments and local health authorities should take timely intervention measures to alleviate symptoms and provide psychological support. Supported by the Project of Science and Technology Department of Sichuan Province (2020ZYD013).

Design and implementation of an adaptive multilevel wireless security system using IoT

Securing property plays a crucial role in human life. Therefore, an adaptive multilevel wireless security system (ML-WSS) based on the internet of things (IoT) has been proposed to observe and secure a certain place. ML-WSS consists of hardware and software components, such as a set of sensors, Wi-Fi module, and operation and monitoring mobile application (OMM). The OMM application is designed to remotely monitor and control the proposed system through the Internet and by using ThingSpeak cloud as a data store. The proposed scheme is based on dividing the required zone of the place into three regions (levels), low-risk region (LRR) as level-1, moderate-risk region (MRR) level-2, and high-risk region (HRR) as level-3. Each level may contain one or set of sensors, so the number of sensors, their placement, and under which level is labelled is specified according to the security requirements. Several processes are done based on these levels when a breach occurs in the system. Mathematical model and pseudocode were created to illustrate the mechanism of the proposed system. The results show that the proposed system has been implemented successfully and the number of breaches that occurs in level-3 area was reduced by 50% as compared to level-1.

Risk Assessment of Industrial Fires for Surrounding Vulnerable Facilities Using a Multi-Criteria Decision Support Approach and GIS

The fires encountered in the buildings and facilities of industrial areas make up quite a small proportion of all fire cases. However, in terms of the heat release rate, size of the burned area, damage, and impact zone, such fires have a large impact as compared to other fire cases. All fires have risk in terms of propagation. However, since fires in industrial structures and plants have rather high levels, qualitatively and quantitatively, compared to residential fires and other types of fires, it should be regarded as necessary to research them extensively. In this study, fires that have broken out in various places around Turkey, such as in factories, cold storage plants, and manufacturing facilities, were investigated. We aimed to determine the level of risk of the occurrence of these fires in the environment. A large amount of detailed information gathered about these fires was analyzed. This information includes data about the causes of the fires, deformation data of various materials, data on technical problems, data on financial damage levels, and data on fire patterns. We found 40 of these fire cases in total, and the case data were used to calculate the risk scores with the Geographic Information System (GIS), Analytical Hierarchy Process (AHP), and Inverse Distance Weight (IDW) methods. For each fire case, places sensitive to damage and losses were assessed according to six main criteria. Buffer analysis maps were generated for the 40 fire cases, and the cases were ordered based on their overall risk scores. In this ordering, fire case number 21 was found in the riskiest region, and fire cases 32, 17, and 31 were found in the low-risk region. Fire case number 21 occurred in a factory used for manufacturing fabric. This factory works with high volumes of acrylic, polyester, and other raw materials. In addition, there are some structures in very close proximity. It was observed that fire cases could be well differentiated depending on the selected criteria in the model applied.