Machine-Learning Applications for the Retrieval of Forest Biomass from Airborne P-Band SAR Data

This study aimed at evaluating the potential of machine learning (ML) for estimating forest biomass from polarimetric Synthetic Aperture Radar (SAR) data. Retrieval algorithms based on two different machine-learning methods, namely Artificial Neural Networks (ANNs) and Supported Vector Regressions (SVRs), were implemented and validated using the airborne polarimetric SAR data derived from the AfriSAR, BioSAR, and TropiSAR campaigns. These datasets, composed of polarimetric airborne SAR data at P-band and corresponding biomass values from in situ and LiDAR measurements, were made available by the European Space Agency (ESA) in the framework of the Biomass Retrieval Algorithm Inter-Comparison Exercise (BRIX). The sensitivity of the SAR measurements at all polarizations to the target biomass was evaluated on the entire set of data from all the campaigns, and separately on the dataset of each campaign. Based on the results of the sensitivity analysis, the retrieval was attempted by implementing general algorithms, using the entire dataset, and specific algorithms, using data of each campaign. Algorithm inputs are the SAR data and the corresponding local incidence angles, and output is the estimated biomass. To allow the comparison, both ANN and SVR were trained using the same subset of data, composed of 50% of the available dataset, and validated on the remaining part of the dataset. The validation of the algorithms demonstrated that both machine-learning methods were able to estimate the forest biomass with comparable accuracies. In detail, the validation of the general ANN algorithm resulted in a correlation coefficient R = 0.88, RMSE = 60 t/ha, and negligible BIAS, while the specific ANN for data obtained R from 0.78 to 0.94 and RMSE between 15 and 50 t/ha, depending on the dataset. Similarly, the general SVR was able to estimate the target parameter with R = 0.84, RMSE = 69 t/ha, and BIAS negligible, while the specific algorithms obtained 0.22 ≤ R ≤ 0.92 and 19 ≤ RMSE ≤ 70 (t/ha). The study also pointed out that the computational cost is similar for both methods. In this respect, the training is the only time-demanding part, while applying the trained algorithm to the validation set or to any other dataset occurs in near real time. As a final step of the study, the ANN and SVR algorithms were applied to the available SAR images for obtaining biomass maps from the available SAR images

Life during COVID-19 lockdown in Italy: the influence of cognitive state on psychosocial, behavioral and lifestyle profiles of older adults.

Few studies have examined lockdown effects on the way of living and well-being of older adults stratified by cognitive state. Since cognitive deficits are common in this population, we investigated how cognition influenced their understanding of the pandemic, socio-behavioral responses and lifestyle adaptations during lockdown, and how these factors affected their mood or memory.Telephone-based survey involving 204 older adults ≥65 y/o (median: 82) with previous assessments of cognitive state: 164 normal-old (NOLD), 24 mild-neurocognitive disorder (mild-NCD), 18 mild-moderate dementia. A structured questionnaire was developed to assess psychological and socio-behavioral variables. Logistic regression was used to ascertain their effects on mood and memory.With increasing cognitive deficits, understanding of the pandemic and the ability to follow lockdown policies, adapt to lifestyle changes, and maintain remote interactions decreased. Participants with dementia were more depressed; NOLDs remained physically and mentally active but were more bored and anxious. Sleeping and health problems independently increased the likelihood of depression (OR: 2.29; CI: 1.06-4.93;NOLD and mild-NCD groups showed similar mood-behavioral profiles suggesting better tolerance of lockdown. Those with dementia were unable to adapt and suffered from depression and cognitive complaints. To counteract lockdown effects, physical and mental activities and digital literacy should be encouraged

sclerostin levels in uremic patients a link between bone and vascular disease

AbstractSclerostin is a marker of low-turnover bone disease in end stage renal disease patients. The aim of this study was to evaluate serum sclerostin in uremic patients, analyzing its behavior during a single hemodialysis session. Twenty-one adult patients on intermittent hemodialysis treatment were enrolled. Acetate Free Bio-filtration (AFB) was the technique employed. Uremic patients were characterized by higher levels of serum sclerostin when compared with values observed in healthy subjects. Sclerostin assessed in pre-dialysis samples was 1.4 ± 1.02 ng/mL, whereas, in post dialysis samples, a reduction of sclerostin values was observed (0.8 ± 0.6 ng/mL; p: 0.008). Sclerostin correlated with parameters of dialysis adequacy, such as creatinine levels and Kt/V values, and it was significantly associated with atherosclerotic disease. Receiver operating characteristics analysis revealed a good diagnostic profile in identifying atherosclerotic disease. Sclerostin, a full dialyzable substance during AFB di..

Rhabdomyoblastic Differentiation in Head and Neck Malignancies Other Than Rhabdomyosarcoma

Rhabdomyosarcoma is a relatively common soft tissue sarcoma that frequently affects children and adolescents and may involve the head and neck. Rhabdomyosarcoma is defined by skeletal muscle differentiation which can be suggested by routine histology and confirmed by immunohistochemistry for the skeletal muscle-specific markers myogenin or myoD1. At the same time, it must be remembered that when it comes to head and neck malignancies, skeletal muscle differentiation is not limited to rhabdomyosarcoma. A lack of awareness of this phenomenon could lead to misdiagnosis and, subsequently, inappropriate therapeutic interventions. This review focuses on malignant neoplasms of the head and neck other than rhabdomyosarcoma that may exhibit rhabdomyoblastic differentiation, with an emphasis on strategies to resolve the diagnostic dilemmas these tumors may present. Axiomatically, no primary central nervous system tumors will be discussed.info:eu-repo/semantics/publishedVersio

Do target prices predict rating changes?

Both bond rating agencies and equity analysts evaluate publicly traded companies releasing their opinions to investors. Yet, the quality of this information can be extremely volatile. A large number of studies have investigated the accuracy of debt and equity analysts’ research and the price effect of the release of new information to the market. Both rating actions and equity research revisions have proven to deliver consistent and statistically significant price effect on the underlying asset classes, thus allowing to conclude that investors consider this information valuable. Predicting rating actions would therefore be beneficial to both companies and investors. Surprisingly, though, only a few studies have addressed this issue. In this paper we develop a model to predict rating actions by looking at previously issued target prices. Since target prices provide a valuation of the equity value of a company which is by its very nature more volatile, a change in target prices could signal a change in the underlying robustness of a company’s operations which can eventually have an impact on debt rating. Collecting a unique dataset of 416 rating actions and 14.046 target prices issued by 75 different equity analysts and 3 different rating agencies on companies listed in the European market (UK, Germany, Euronext, France and Italy) between 1/1/2000 and 12/31/2005, we find that positive rating events are anticipated by consistent increases of the target prices released in the four months before the rating action. The evidence is slightly weaker for negative rating events, since significant reductions in target prices are observable only in a shorter window (three months). Our results are aligned with previous studies showing analysts’ overly optimistic behavior and analysts’ reluctance in reducing target prices over time. Controlling for the macro industry of each company, we find evidence that target prices are more likely to predict a rating action for financial rather than industrial companies which supports Gropp and Richards (2001) and Schweitzer et al. (1992) results who point out that differences in regulatory regimes, which imply different degrees of transparency, may affect the quality and accuracy of publicly available information

Ruolo della colposcopia nel management delle pazienti trattate con terapia ablativa locale per lesioni cervicali di basso grado (L-SIL)

La citologia e la colposcopia sono oggi due mezzi diagnostici fondamentali per la diagnosi precancerosa cervicale. Nonostante il Pap-test sia stato il primo esame usato su larga scala per la diagnosi precoce dei tumori del collo dell'utero, è opportuno che le donne che manifestano anomalie citologiche al Pap-test, vengano sottoposte ad esame di secondo livello, cioè a colposcopia. Il protocollo per il follow-up delle lesioni squamose intraepiteliali di basso grado (L-SIL), trattate con laser terapia o con diatermocoagulazione, dovrebbe prevedere un primo controllo a distanza di 3-6 mesi dal trattamento, effettuando l?esame citologico in associazione ad una colposcopia. L?obiettivo del nostro studio, di tipo retrospettivo, è quello di dimostrare che l'utilizzo della citologia per la gestione del follow-up della L-SIL rappresenta un metodo sicuro ed efficace, e che l'associazione dell'esame colposcopico offre un beneficio supplementare. Dal 2000 al 2004 abbiamo preso in esame 120 pazienti, che all'esame citologico presentavano una lesione di basso grado, diagnosi istologica di L-SIL e che avevano subito un trattamento locale ablativo. Dopo un periodo variabile da 3 a 6 mesi dal trattamento della lesione, le pazienti sono state sottoposte ad un follow-up combinato citologico e colposcopico. Se entrambi gli esami erano normali, la paziente veniva congedata ed invitata ad eseguire una citologia con eventuale colposcopia dopo 6 mesi. In caso di positività alla citologia o alla colposcopia abbiamo eseguito invece una biopsia mirata. Raccolti i dati, le citologie anormali, i referti colposcopici atipici, l'istologia delle lesioni bioptizzate, ed esaminate le modalità di trattamento effettuate, abbiamo eseguito un'analisi descrittiva

Valore diagnostico delle alterazioni citologiche associate a lesioni preneoplastiche della cervice uterina rilevabili al Pap-test: la nostra esperienza

Il cervico-carcinoma rappresenta ancora oggi la seconda neoplasia più frequente nel sesso femminile a livello mondiale, preceduta solo dal carcinoma della mammella. Nonostante la diffusione del Pap-test come mezzo di screening abbia consentito, nell'ultimo ventennio, una riduzione dei tassi di incidenza e mortalità per cervico-carcinoma, la mortalità è ancora oggi estremamente elevata. Inoltre, le infezioni virali da HPV, con le relative alterazioni del tratto genitale femminile inferiore, risultano in aumento, specialmente nei Paesi in via di sviluppo; e ciò è da attribuirsi al cambiamento delle abitudini sessuali. Nel nostro studio abbiamo fatto riferimento all'associazione fra l'infezione da Papillomavirus (HPV) e la genesi del carcinoma cervicale, evidenziando le alterazioni apprezzabili al Pap-test, considerate oggi come marcatori citologici dell'infezione da HPV, quali la coilocitosi e la discheratosi. Tra Febbraio 2000 e Giugno 2003 abbiamo arruolato 2.000 pazienti, asintomatiche, fra i 15 e i 65 anni e le abbiamo sottoposte ad esame citopatologico. Abbiamo analizzato poi i dati raccolti e calcolato la percentuale dei casi in cui la discheratosi era realmente associata ad infezione da HPV, al fine di valutare se questa alterazione possa essere considerata patognomonica di lesione virale. Pertanto nelle pazienti in cui al Pap-test era presente discheratosi, abbiamo eseguito esame colposcopico in associazione a biopsia; se l'infezione veniva accertata, veniva eseguito il trattamento ablativo della lesione