Influences of the Clearness Index on UV Solar Radiation for Two Locations in the Tibetan Plateau——Lhasa and Haibei

Ultraviolet （UV） solar radiation has a significant influence on human health, the environment and climate. A series of measurements, including UV radiation （290 400 nm） and global solar radiation （Rs）, were continuously recorded from August 2004 at the Lhasa and Haibei sites on the Tibetan Plateau. Both observation sites＇ altitudes are above 3000 m and have similar meteorological conditions. The data from 2005 2006 was used to identify the varying characteristics of UV radiation. It＇s relation to the clearness index Ks, the relative optical mass mr, and Rs were established. The annual mean values of total daily UV radiation are 0.92 and 0.67 MJ m^-2 at Lhasa and Haibei, respectively. The UV radiation in Lhasa represented 4.6% of the global solar radiation while in Haibei this percentage was 4.2%. In the case of clear days （Ks 〉 0.8）, these percentages ranged between 4.0% and 4.5% in Lhasa and between 5.1% and 5.5% in Haibei. In the case of cloudy days （Ks 〈 0.4）, these percentages ranged from 4.4% to 6.8% in Lhasa and from 5.1% to 5.5% in Haibei. The maximum values of UV radiation for each relative optical mass diminished exponentially with mr. Thus, for Lhasa and Haibei, UV=46.25mr-129, and UV=51.76mr-142, respectively. The results of this study can be used to obtain more UV radiation data for the study of UV climate characteristics, the effects of UV on ecological processes and the feedback of the thinning of the stratospheric ozone, from more routine measurements Rs data.

Estimation of Global Solar Radiation Using Clearness Index and Cloud Transmittance Factor at Trans-Himalayan Region in Nepal

This paper presents the global solar radiation (GSR) and cloud transmittance factor (cf) measured at the horizontal surface over a period of one year from 2009 to 2010 using CMP6 Pyranometer and NILUUV Irradiance Meter at Lukla (Latitude 26.69oN,Longitude 86.73?E and Altitude 2850 m) in the foothills of the Mt Everest (8850 m high). Monthly and seasonal variations of global solar radiation as well as correlation between clearness index and cloud transmittance factor at Lukla are presented. The annual average daily global solar radiation is about 3.83 kWh/sq·m/day which is sufficient to promote solar active and passive energy technology at high mountain terrain where there is no other viable alternative sources of energy. The maximum and minimum global solar radiation of 5.33 and 2.08 kWh/sq·m/day is recorded in April and September 2010 respectively. The seasonal variation of solar energy is about 2.87 kWh/sq·m/day and 4.83 kWh/sq·m/day in summer and spring respectively which is not in line with the general trend. The coefficient of determination (R2) between cloud transmittance factor (cf) and clearness factor (K) is found to be 0.97. This novel result can be utilized to estimate the global solar radiation at the horizontal surface where K and cf are available.

Classification of Hourly Clearness Index of Solar Radiation in the District of Yamoussoukro

The exploitation of systems using solar energy as a source of energy is not fluctuations free because of short passage of clouds on solar radiation. The amplitude, the persistence and the frequency of these fluctuations should be analyzed with appropriate tools, instead of focusing on their location over time. The analysis of these fluctuations should use the instantaneous clearness index whose distribution is given as a first approximation which is independent not only of the season but also of the site. It is important to evaluate the potential solar energy in a region. Indeed such evaluation helps the decision-makers in their reflections on agricultural or photovoltaic solar projects. Then this study was conducted for a predictive purpose. The method used in our work combines the classification method which is the hierarchical ascending classification and two partitioning methods, the principal component?analysis and the K-means method. The partitioning method enabled to?achieve a number of well-known situations (in advance) that are representative of the day. The study was based on the data of a climatic weather station in the district of Yamoussoukro located in the center region of Côte d’Ivoire during the 2017 year. Using the clearness index, the study allowed the classification of the solar radiation in the region. Thus, it showed that only 346 days of the 365 days in 2017 were classified (95%). We identified three clusters of days, the cloudy sky (29%), the partly cloudy sky?(32%) and the clear sky (39%). The statistical tests used for the characterization?of these clusters will be detailed in a future study.

Estimation of Daily Global Solar Radiation with Different Sunshine-Based Models for Some Burundian Stations

Sunshine duration (S) based empirical equations have been employed in this study to estimate the daily global solar radiation on a horizontal surface (G) for six meteorological stations in Burundi. Those equations include the Ångström-Prescott linear model and four amongst its derivatives, i.e. logarithmic, exponential, power and quadratic functions. Monthly mean values of daily global solar radiation and sunshine duration data for a period of 20 to 23 years, from the Geographical Institute of Burundi (IGEBU), have been used. For any of the six stations, ten single or double linear regressions have been developed from the above-said five functions, to relate in terms of monthly mean values, the daily clearness index () to each of the next two kinds of relative sunshine duration (RSD): and . In those ratios, G0, S0 and stand for the extraterrestrial daily solar radiation on a horizontal surface, the day length and the modified day length taking into account the natural site’s horizon, respectively. According to the calculated mean values of the clearness index and the RSD, each station experiences a high number of fairly clear (or partially cloudy) days. Estimated values of the dependent variable (y) in each developed linear regression, have been compared to measured values in terms of the coefficients of correlation (R) and of determination (R2), the mean bias error (MBE), the root mean square error (RMSE) and the t-statistics. Mean values of these statistical indicators have been used to rank, according to decreasing performance level, firstly the ten developed equations per station on account of the overall six stations, secondly the six stations on account of the overall ten equations. Nevertheless, the obtained values of those indicators lay in the next ranges for all the developed sixty equations:;;;, with . These results lead to assert that any of the sixty developed linear regressions (and thus equations in terms of and ), fits very adequately measured data, and should be used to estimate monthly average daily global solar radiation with sunshine duration for the relevant station. It is also found that using as RSD, is slightly more advantageous than using for estimating the monthly average daily clearness index, . Moreover, values of statistical indicators of this study match adequately data from other works on the same kinds of empirical equations.

60kV联合深度学习重建算法在主动脉CT血管造影中的可行性研究

目的:探讨60 kV联合基于深度学习的ClearInfinity(CI)重建算法在主动脉CT血管造影中的可行性。方法:收集2023年7—9月因主动脉疾病在郑州大学第一附属医院拟行主动脉CT血管造影(CTA)的受检者73例,按照随机数字表法分为A组(n=36)和B组(n=37)。A组受检者采用100 kV行常规扫描和重建;B组受检者采用60 kV行CT扫描,再依据重建算法不同分为B1、B2、B3亚组,分别采用30%~90%(间隔30%)CI算法重建,比较各组受检者辐射剂量以及图像质量。结果:除A组和B1组的信噪比(SNR)值在降主动脉、髂总动脉外,其余各组间SNR值比较,差异有统计学意义(均P <0.05)。除A组和B1组在降主动脉层面外,其余各组间对比噪声比(CNR)值比较,差异有统计学意义(均P <0.05)。图像主观评分A组与B2组比较,差异无统计学意义(P> 0.05),A组、B1组和B3组主观评分比较,差异有统计学意义(P <0.05)。结论:对体重指数(BMI)<26 kg/m~2的正常体型受检者,采用60 kV行主动脉CTA能大幅降低辐射剂量,联合深度学习CI重建算法能显著降低图像噪声,改善图像质量以达到诊断需求。

A"messenger zone hypothesis"based on the visual three-dimensional spatial distribution of motoneurons innervating deep limb muscles

Coordinated contraction of skeletal muscles relies on selective connections between the muscles and multiple classes of the spinal motoneuro ns.Howeve r,current research on the spatial location of the spinal motoneurons innervating differe nt muscles is limited.In this study,we investigated the spatial distribution and relative position of different motoneurons that control the deep muscles of the mouse hindlimbs,which were innervated by the obturator nerve,femoral nerve,inferior gluteal nerve,deep pe roneal nerve,and tibial nerve.Locations were visualized by combining a multiplex retrograde tracking technique compatible with three-dimensional imaging of solvent-cleared o rgans(3DISCO)and 3-D imaging technology based on lightsheet fluorescence microscopy(LSFM).Additionally,we propose the hypothesis that"messenger zones"exist as interlaced areas between the motoneuron pools that dominate the synergistic or antagonist muscle groups.We hypothesize that these interlaced neurons may participate in muscle coordination as messenger neurons.Analysis revealed the precise mutual positional relationships among the many motoneurons that innervate different deep muscles of the mouse.Not only do these findings update and supplement our knowledge regarding the overall spatial layout of spinal motoneurons that control mouse limb muscles,but they also provide insights into the mechanisms through which muscle activity is coordinated and the architecture of motor circuits.

MACS-W:A modified optical clearing agent for imaging 3D cell cultures

Three-dimensional(3D)cell cultures have contributed to a variety of biological research fields by filling the gap between monolayers and animal models.The modern optical sectioning microscopic methods make it possible to probe the complexity of 3D cell cultures but are limited by the inherent opaqueness.While tissue optical clearing methods have emerged as powerful tools for investigating whole-mount tissues in 3D,they often have limitations,such as being too harsh for fragile 3D cell cultures,requiring complex handling protocols,or inducing tissue deformation with shrinkage or expansion.To address this issue,we proposed a modified optical clearing method for 3D cell cultures,called MACS-W,which is simple,highly efficient,and morphology-preserving.In our evaluation of MACS-W,we found that it exhibits excellent clearing capability in just 10 min,with minimal deformation,and helps drug evaluation on tumor spheroids.In summary,MACS-W is a fast,minimally-deformative and fluorescence compatible clearing method that has the potential to be widely used in the studies of 3D cell cultures.

Tissue optical clearing enhances efficacy of vascular targeted photodynamic therapy of mouse dorsal skin

Vascular-targeted photodynamic therapy(V-PDT)is an effective treatment for port wine stains(PWS).However,repeated treatment is usually needed to achieve optimal treatment outcomes,possibly due to the limited treatment light penetration depth in the PWS lesion.The optical clearing technique can increase light penetration in depth by reducing light scattering.This study aimed to investigate the V-PDT in combination with an optical clearing agent(OCA)for the therapeutic enhancement of V-PDT in the rodent skinfold window chamber model.Vascular responses were closely monitored with laser speckle contrast imaging(LSCI),optical coherence tomography angiography,and stereo microscope before,during,and after the treatment.We further quantitatively demonstrated the effects of V-PDT in combination with OCA on the blood flow and blood vessel size of skin microvasculature.The combination of OCA and V-PDT resulted in significant vascular damage,including vasoconstriction and the reduction of blood flow.Our results indicate the promising potential of OCA for enhancing V-PDT for treating vascular-related diseases,including PWS.

DNBP-CCA:A Novel Approach to Enhancing Heterogeneous Data Traffic and Reliable Data Transmission for Body Area Network

The increased adoption of Internet of Medical Things (IoMT) technologies has resulted in the widespread use ofBody Area Networks (BANs) in medical and non-medical domains. However, the performance of IEEE 802.15.4-based BANs is impacted by challenges related to heterogeneous data traffic requirements among nodes, includingcontention during finite backoff periods, association delays, and traffic channel access through clear channelassessment (CCA) algorithms. These challenges lead to increased packet collisions, queuing delays, retransmissions,and the neglect of critical traffic, thereby hindering performance indicators such as throughput, packet deliveryratio, packet drop rate, and packet delay. Therefore, we propose Dynamic Next Backoff Period and Clear ChannelAssessment (DNBP-CCA) schemes to address these issues. The DNBP-CCA schemes leverage a combination ofthe Dynamic Next Backoff Period (DNBP) scheme and the Dynamic Next Clear Channel Assessment (DNCCA)scheme. The DNBP scheme employs a fuzzy Takagi, Sugeno, and Kang (TSK) model’s inference system toquantitatively analyze backoff exponent, channel clearance, collision ratio, and data rate as input parameters. Onthe other hand, the DNCCA scheme dynamically adapts the CCA process based on requested data transmission tothe coordinator, considering input parameters such as buffer status ratio and acknowledgement ratio. As a result,simulations demonstrate that our proposed schemes are better than some existing representative approaches andenhance data transmission, reduce node collisions, improve average throughput, and packet delivery ratio, anddecrease average packet drop rate and packet delay.

Neural stem cell-derived exosomes promote mitochondrial biogenesis and restore abnormal protein distribution in a mouse model of Alzheimer's disease

Mitochondrial dysfunction is a hallmark of Alzheimer’s disease.We previously showed that neural stem cell-derived extracellular vesicles improved mitochondrial function in the cortex of AP P/PS1 mice.Because Alzheimer’s disease affects the entire brain,further research is needed to elucidate alterations in mitochondrial metabolism in the brain as a whole.Here,we investigated the expression of several important mitochondrial biogenesis-related cytokines in multiple brain regions after treatment with neural stem cell-derived exosomes and used a combination of whole brain clearing,immunostaining,and lightsheet imaging to clarify their spatial distribution.Additionally,to clarify whether the sirtuin 1(SIRT1)-related pathway plays a regulatory role in neural stem cell-de rived exosomes interfering with mitochondrial functional changes,we generated a novel nervous system-SIRT1 conditional knoc kout AP P/PS1mouse model.Our findings demonstrate that neural stem cell-de rived exosomes significantly increase SIRT1 levels,enhance the production of mitochondrial biogenesis-related fa ctors,and inhibit astrocyte activation,but do not suppress amyloid-βproduction.Thus,neural stem cell-derived exosomes may be a useful therapeutic strategy for Alzheimer’s disease that activates the SIRT1-PGC1αsignaling pathway and increases NRF1 and COXIV synthesis to improve mitochondrial biogenesis.In addition,we showed that the spatial distribution of mitochondrial biogenesis-related factors is disrupted in Alzheimer’s disease,and that neural stem cell-derived exosome treatment can reverse this effect,indicating that neural stem cell-derived exosomes promote mitochondrial biogenesis.

Metastatic clear cell sarcoma of the pancreas:A rare case report

BACKGROUND Clear cell sarcoma(CCS)is a rare soft-tissue sarcoma.The most common metastatic sites for CCS are the lungs,bones and brain.CCS is highly invasive and mainly metastasizes to the lung,followed by the bone and brain;however,pancreatic metastasis is relatively rare.CASE SUMMARY We report on a rare case of CCS with pancreatic metastasis in a 47-year-old man.The patient had a relevant medical history 3 years ago,with abdominal pain as the main clinical manifestation.No abnormalities were observed on physical examination and the tumor was found on abdominal computed tomography.Based on the medical history and postoperative pathology,the patient was diagnosed with CCS with pancreatic metastasis.The patient was successfully treated with surgical interventions,including distal pancreatectomy and sple-nectomy.CONCLUSION This report summarizes the available treatment modalities for CCS and the importance of regular postoperative follow-up for patients with CCS.

Low expression of fatty acid oxidation related gene ACADM indicates poor prognosis of renal clear cell carcinoma and is related to tumor immune infltration

This research aims to identify the key fatty acid beta-oxidation(FAO)genes that are altered in kidney renal clear cell carcinoma(KIRC)and to analyze the role of these genes in KIRC The Gene Expression Omnibus(GEO)and FAO datasets were used to identify these key genes.Wilcoxon rank sum test was used to assess the levels of acyl-CoA dehydrogenase medium chain(ACADM)between KIRC and non cancer samples.The logistic regression and Wilcoxon rank sum test were used to explore the association between ACADM and clinical features.The diagnostic performance of ACADM for KIRC was asessed using a diagnostic receiver operating ch aracteristic(ROC)curve.The co-expressed genes of ACADM were identifed in LinkedOmics database,and their function and pathway enrichment were analyzed.The correlation between ACADM expression level and immune infitration was analyzed by Gene Set Variation Analysis(GSVA)method Additionally,the proliferation,migration,and invasion abilities of KIRC cells were assessed after overexpressing ACADM.Following differential analysis and intersection,we identifed six hub genes,induding ACADM.We found that the expression level of ACADM was decreased in KIRC tissues and had a better diagnostic efect(AUC=0.916).Survival analysis suggested that patients with decreased ACADM expression had a worse prognosis.According to correlation analysis,a variety of dinical features were associated with the expression level of ACADML By analyzing the infiltration level of immune cells,we found that ACADM may be related to the enrichment of immune cells.Finally,ACADM overexpression inhibited proliferation,migration,and invasion of KIRC cells.In conclusion,our findings suggest that reduced ACADM expression in KIRC patients is indicative of poor prognosis.These results imply that ACADM may be a diagnostic and prognostic marker for individuals with KIRC,offering a reference for dinicians in diagnosis and treatment.

CARD11 serves as a therapeutic biomarker for the drug therapies of ccRCC

Background:The incidence of clear cell renal cell carcinoma(ccRCC)is globally high;however,despite the introduction of innovative drug therapies,there remains a lack of effective biomarkers for evaluating treatment response.Recently,Caspase recruiting domain-containing protein 11(CARD11)has garnered attention due to its significant association with tumor development and the immune system.Methods:The expression of CARD11 mRNA and protein in ccRCC were analyzed by public database and immunohistochemistry.The focus of this study is on the epigenomic modifications of CARD11,its expression of ccRCC immunophenotype,and its correlation with response to immunotherapy and targeted therapy.Furthermore,to investigate the mechanism of this molecule’s influence on different biological behaviors of cells,cell tests in vitro have been conducted to observe the impact of its expression level.Results:CARD11 expression was upregulated which may be mainly modified by body methylation and was correlated with poor prognosis in ccRCC.In the tumor microenvironment of ccRCC,CARD11 expression was positively correlated with increased T lymphocyte infiltration and increased expression of inhibitory immune checkpoints.Moreover,ccRCC patients with high CARD11 expression had a better response to immunotherapy and targeted therapy.The knockdown of CARD11 ultimately suppressed the proliferation,migration,and invasion capabilities of ccRCC cells while simultaneously enhancing tumor cell apoptosis.Conclusion:We identified CARD11 as a novel therapeutic biomarker for immunotherapy and targeted therapy in ccRCC.

Left lower lobe sleeve resection for the clear cell variant of pulmonary mucoepidermoid carcinoma:A case report

BACKGROUND Pulmonary mucoepidermoid carcinoma(PMEC)is a rare malignancy that arises from minor salivary glands within the tracheobronchial tree.The clear cell variant of PMEC is exceptionally uncommon and presents notable diagnostic challenges,primarily attributable to its morphological similarity to other tumors containing clear cells.CASE SUMMARY A 22-year-old male,formerly in good health,came in with a two-month duration of persistent cough and production of sputum.Subsequent imaging and bronchoscopy examinations revealed a 2 cm tumor in the distal left main bronchus,which resulted in complete atelectasis of the left lung.Further assessment via positron emission tomography/computed tomography scans and endoscopic biopsy confirmed the primary malignant nature of the tumor,charac-terized by clear cell morphology in most of the tumor cells.The patient underwent a left lower lobe sleeve resection accompanied by systematic mediastinal lymph node dissection.Molecular pathology analysis subsequently revealed a CRTC3-MAML2 gene fusion,leading to a definitive pathological diagnosis of the clear cell variant of PMEC,staged as T2N0M0.After surgery,the patient experienced a smooth recovery and exhibited no signs of recurrence during the one-and-a-half-year follow-up period.CONCLUSION This article describes an unusual case of a clear cell variant of PMEC characterized by the presence of a CRTC3-MAML2 gene fusion in a 22-year-old male.The patient underwent successful left lower lobe sleeve resection.This case underscores the distinctive challenges associated with diagnosing and treating this uncommon malignancy,underscoring the importance of precise diagnosis and personalized treatment strategies.

A Study on the Influence of Social Media Use on Psychological Anxiety among Young Women

To explore the relationship between social influence,social comparison,clarity of self-concept,and psychological anxiety among young women during their usage of social networking sites,our study selected 338 young women aged 14-34 from the social site platforms of Little Red Book and Weibo for questionnaire surveys.The Passive Social Network Utilization Scale,Social Comparison Scale(SCS),Social Influence Questionnaire,Self-Concept Clarity Scale(SCCS),and Generalized Anxiety Disorder Scale(GAD-7)were employed to measure the subjects.Our results show that the frequency of passive social media use is positively related to the level of psychological anxiety.Social comparison,social influence,and unclear self-concepts under social media use are negatively predictive of psychological anxiety.The chain mediation effects indicate that social comparison and social influence under social media use negatively predict the clarity of self-concept,thus having a negative impact on the psychological health of young women.Therefore,young women should strengthen their self-concepts,control their frequency of social media usage,avoid addiction,and pay special attention to their frequency of passive use,in order to protect their psychological health.Our study provides some practical implications and insights regarding the relationship between young women’s social media use and psychological health.

Economy Function in the Mode of Sustainable Development

To implement the previously formulated principles of sustainable economic development, all solutions of the linear system of equations and inequalities, which are satisfied by the vector of real consumption, are completely described. It is established that the vector of real consumption with the minimum level of excess supply is determined by the solution of some quadratic programming problem. The necessary and sufficient conditions are established under which the economic system, described by the “input-output” production model, functions in the mode of sustainable development. A complete description of the equilibrium states for which markets are partially cleared in the economy model of production “input-output” is given, on the basis that all solutions of system of linear equations and inequalities are completely described. The existence of a family of taxation vectors in the “input-output” model of production, under which the economic system is able to function in the mode of sustainable development, is proved. Restrictions were found for the vector of taxation in the economic system, under which the economic system is able to function in the mode of sustainable development.

Network pharmacology and molecular docking analysis reveal insights into the molecular mechanism of Gualou Qumai Wan in clear cell renal cell carcinoma

Background:To initially clarify the potential therapeutic targets and pharmacological mechanism regarding Gualou Qumai Wan(GQW),a kind of traditional Chinese medicine(TCM),in clear cell renal cell carcinoma(ccRCC)by virtue of the network pharmacology analysis and molecular docking analysis.Methods:The screening of bioactive components and targets of GQW was based on the Traditional Chinese Medicine System Pharmacology(TCMSP)and the UniProt platform served for standardizing their targets.Online Mendelian Inheritance in Man(OMIM),PharmGkb,TTD,DrugBank and GeneCards databases were searched to collect the disease targets of ccRCC.Cytoscape assisted in constructing herb-compound-target(H-C-T)networks.The STRING database was searched for constructing the target protein-protein interaction(PPI)networks,while the R programming language served for analyzing GO functional terms and the KEGG pathways related to potential targets.Analyses of core genes related to survival and tumor microenvironment(TME)were conducted respectively based on the GEPIA2 database and TIMER 2.0 database.Human Protein Atlas(HPA)and The Cancer Genome Atlas(TCGA)helped to obtain core genes’protein expression as well as transcriptome expression level.Autodock Vina software validated the molecular docking regarding GQW components and pivotal targets.Results:The constructed H-C-T networks mainly had 33 compounds and 65 targets.A topological analysis of the PPI network identified that ESR1,AKT1,HIF1A,PTGS2,TP53 and VEGFA serve as core targets in the way GQW affects ccRCC.According to the GO and KEGG pathway enrichment analyses,the effects of GQW are mediated by genes related to hypoxia and oxidative stress as well as the Chemical carcinogenesis-receptor activation and PI3K-Akt signaling pathways.AKT1 shows a close relation to the recruitment of various immune cells and can remarkably affect disease prognosis according to reports.Molecular docking and molecular dynamics simulations showed that diosgenin has higher affinity with core targets.Conclusion:The study makes a comprehensive explanation of the biological activity,potential targets,as well as molecular mechanism regarding GQW against ccRCC,which promisingly assists in revealing the action mechanism of TCM formulae in disease treatment and the respective and scientific basis.

Forecasting Global Solar Insolation Using the Ensemble Kalman Filter Based Clearness Index Model

This paper describes a novel approach in developing a model for forecasting of global insolation on a horizontal plane.In the proposed forecasting model,constraints,such as latitude and whole precipitable water content in vertical column of that location,are used.These parameters can be easily measurable with a global positioning system(GPS).The earlier model was developed by using the above datasets generated from different locations in India.The model has been verified by calculating theoretical global insolation for different sites covering east,west,north,south and the central region with the measured values from the same locations.The model has also been validated on a region,from which data was not used during the development of the model.In the model,clearness index coefficients(KT)are updated using the ensemble Kalman filter(EnKF)algorithm.The forecasting efficacies using the KT model and EnKF algorithm have also been verified by comparing two popular algorithms,namely the recursive least square(RLS)and Kalman filter(KF)algorithms.The minimum mean absolute percentage error(MAPE),mean square error(MSE)and correlation coefficient(R)value obtained in global solar insolation estimations using EnKF in one of the locations are 2.4%,0.0285 and 0.9866 respectively.

Clear Cell Pleomorphic Dermal Sarcoma: A Case Report and Literature Review

Introduction: Atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS) are one spectrum of rare cutaneous neoplasms that typically arise in sun-exposed skin of older population. AFX/PDS is essentially diagnosis of exclusion requiring Immunohistochemical work-up to exclude other types of tumors. Case Report: We present a case involving an ulcerated solitary lesion on the scalp of an elderly man. Histological examination revealed that the dermal tumor was composed of large pleomorphic, epithelioid, and spindle cells with clear cytoplasm. These cells were negative for cytokeratins, melanocytes and smooth muscle markers, but positive for CD10. These findings are consistent with a diagnosis of clear cell (CC) PDS. Conclusion: PDS is a low-grade malignancy that can recur locally and metastasize, which is distinguished from AFX by its larger size and the presence of aggressive histopathologic features including deeper invasion into the subcutaneous tissue, tumor necrosis, and lymphovascular and/or perineural involvement. Among several histopathologic variants, the CC variant is extremely rare with only two cases of PDS reported in the literature to date.

Overcast sky condition prevails on and influences the biometeorology of the tropical Andean Páramos

Clouds play a major role in modulating the biometeorological processes. We studied the influence of cloudiness on four biometeorological variables:daily air temperature(Tair), relative humidity(RH),reference evapotranspiration(ETr),and photosynthetic active radiation(PAR), recorded at four sites of Andean Páramos in southern Ecuador during 2.5 to 5.5 years. First, we quantified both the cloud cover percentage(Cloud%) creating cloud masks over the visible bands of Landsat 7 images and the sky condition(K_(T)) using the records of solar and extraterrestrial radiation. Second, we estimated KTfrom Cloud%. Finally, we quantified T_(air), RH, ET_(r), and PAR under clear, cloudy, and overcast K_(T) and their dependence on KT. The average Cloud% ranged between 65%–76%, and KTcorroborated the prevailing overcast sky(between 55% and 72.5% of the days) over the páramos. The proposed model performed well in the sites of calibration(R^(2)= 0.80;MBE = 0.00;RMSE = 0.05) and validation(R^(2)= 0.74;MBE =-0.07;RMSE = 0.11). The overcast sky diminished T_(air)(≤ 10℃), ET_(r)(≤ 1.6 mm day-1), and PAR(4 MJ m^(-2)day^(-1)) and increased RH(≥ 88%),while the variables showed the opposite behavior during the uncommon clear sky(≤ 5.5% of the days).Thus, mostly the dynamic of RH(R^(2)≥ 0.62), ETr(R^(2)≥ 0.85), and PAR(R2≥ 0.77) depended on K_(T). Hence,the prevailing overcast sky influenced the biometeorology of the páramos.