348 research outputs found
Feedback in Practice: The Effects of Written Feedback and Conferences on Student Writing Scores in Ninth Grade English Classrooms
The research question addressed in this study was: how can I improve feedback on student writing in order to help students improve their writing skills? Topics explored in the review of the literature include standards, assessment data, writing instruction, written feedback, surface- and content-level feedback, conferences, text-specific feedback and question asking. Students from two sections of Ninth Grade English at a large suburban high school were divided into two groups. Both groups completed two writing assessments. Each assessment was submitted twice. After the first submission of each assessment, each group received feedback from their teacher on their writing. One group received written feedback and the other group participated in student-teacher conferences. Both groups received both types of feedback over the course of the study. A mixed-methods approach was used. The quantitative data for this study was the average change in scores on rubric criteria from the first submission to the second. The qualitative data was taken from student questionnaires, asking for student opinions on the effectiveness of each type of feedback as well as preferences for one type of feedback or the other. Assessment score data revealed no significant difference between the effectiveness of two types of feedback. Responses to the student questionnaires showed a shift in student preferences from written feedback to conferences over the course of the study. Responses to the student questionnaires also showed a shift in student opinions regarding the effectiveness of each feedback method—from a belief that written feedback is more effective to a belief that conferences are more effective. Ultimately, the results of this study suggest that both written feedback and conferences are valid and effective strategies for providing feedback on student writing and that, if possible, both should be used by teachers. Limitations of the study and ideas for future research are discussed
Elaborazione, adozione delle linee guida e gestione delle lesioni polipoidi nel percorso diagnostico-terapeutico del carcinoma colon-rettale
RIASSUNTO
Le Linee Guida sono raccomandazioni di comportamento clinico, elaborate mediante un processo di revisione sistematica della letteratura e delle opinioni di esperti, con lo scopo di aiutare i medici e i pazienti a decidere le modalità assistenziali più appropriate in specifiche situazioni cliniche e vengono correntemente promosse come mezzo di miglioramento della qualità dell'assistenza, per ottimizzare l'esito degli interventi sui pazienti, scoraggiare l'uso di interventi inefficaci o pericolosi, migliorare e garantire l'adeguatezza delle cure, identificare zone della pratica clinica in cui vi è insufficiente evidenza e aiutare a bilanciare costi e risultati.
Per promuovere la prevenzione di una malattia di grande impatto sociale per diffusione e gravità come il cancro del colon-retto, e' necessario costituire gruppi multidisciplinari ai quali fare afferire i pazienti con lo scopo di pianificare e verbalizzare decisioni diagnostico-terapeutiche specifiche per ogni singolo paziente.
E' consolidata la collaborazione tra anatomo-patologi e gli altri medici (chirurgo, radiologo, oncologo, radioterapista) all'interno dell'Azienda Ospedaliera Pisana per facilitare la diagnosi e l'interpretazione del quadro patologico.
Il ruolo dell' anatomo patologo è fondamentale nella standardizzazione del trattamento delle lesioni preneoplastiche, neoplastiche e della malattia avanzata del colon-retto che si attua per garantire una diagnosi precisa e completa e per ottenere una migliore valutazione prognostica dei pazienti.
Nel periodo compreso tra Gennaio 2011 a Maggio 2014 ho partecipato agli interventi di microchirurgia endoscopica transanale eseguiti dall' Unità di Chirurgia Colon-rettale, orientato i polipi rimossi su appositi supporti, marcato il margine di resezione così da facilitarne durante il campionamento e campionato in sala chirurgica il pezzo operatorio per evitare errori artefattuali che avrebbero potuto rendere difficoltosa la valutazione istologica della microinfiltrazione neoplastica negli adenomi cancerizzati.
Nello stesso periodo, collaborando sempre con l' Unità di Chirurgia Colon-rettale, ho gestito, valutandone direttamente la qualità, l'escissione mesorettale di carcinomi asportati con la tecnica dell'escissione totale del mesoretto, attribuendo il grado di Quirke e correlando al referto finale la documentazione fotografica del pezzo operatorio esaminato al momento dell'esame macroscopico a fresco, del campionamento e della valutazione istologica.
Nella malattia metastatica del colon-retto a livello epatico il trattamento chirurgico viene considerato dopo il downsizing ottenuto con trattamento chemioterapico; la tempistica ed il tipo di intervento dipendono dalle condizioni generali del paziente, dall'estensione della malattia e dalla sintomatologia legata al tumore primitivo.
Negli ultimi mesi ho collaborato con l' Oncologia Universitaria valutando dal punto di vista anatomo-patologico l'effetto tossico della chemioterapia nel parenchima epatico sano da cui ne dipende la funzionalità, importante per poter impostare e continuare una chemioterapia postchirurgica.
L’utilizzo di protocolli diagnostici standardizzati poco costosi, la collaborazione multidisciplinare permettono di stabilire uno specifico follow-up nel caso dei pazienti con lesioni pre-neoplastiche e un iter terapeutico adeguato nel caso dei pazienti con malattia avanzata.
La prevenzione permette quindi, attraverso la diagnosi precoce, la riduzione della morbilità e della mortalità di molte malattie; il comportamento schematizzato delle linee guida facilita la programmazione e il coordinamento nel caso di diagnosi di tumore e di malattia metastatica
SUSTAINABILITY OF POULTRY PRODUCTION USING THE EMERGY APPROACH: COMPARISON OF CONVENTIONAL AND ORGANIC REARING SYSTEMS
The organic production system is an important strategy, compatible with sustainable agriculture, avoiding the use of chemical compounds,limiting the intensity of production and providing controls along the entire chain of production. The aim of this study is to compare conventional and organic poultry production in terms of emergy analysis. The main differences in the two systems were the emergy cost for poultry feed and for cleaning/sanitization of the buildings between successive productive cycles. In both production systems the poultry feed represented more than 50% of the emergy flow. Regarding the agronomic phase, it was shown that almost all the organic crops, avoiding
chemical fertilizers and pesticides, saved around 60% emergy. The emergetic costs for housing of the birds were very similar in both systems. Relating the emergy results with productive performance it is possible to show that, although the annual productive performance was much lower in organic than in conventional (206%), transformity of organic poultry was around 10% lower. Comparison of the organic poultry system with a conventional one from the viewpoint of sustainability showed that all the emergy-based indicators are in favour of the organic farming system with a higher efficiency in transforming the available inputs in the final product, a higher level of renewable inputs, a higher level of local inputs and a lower density of energy and matter flows
Nonlinear approximation with redundant multi-component dictionaries
The problem of efficiently representing and approximating digital data is an open challenge and it is of paramount importance for many applications. This dissertation focuses on the approximation of natural signals as an organized combination of mutually connected elements, preserving and at the same time benefiting from their inherent structure. This is done by decomposing a signal onto a multi-component, redundant collection of functions (dictionary), built by the union of several subdictionaries, each of which is designed to capture a specific behavior of the signal. In this way, instead of representing signals as a superposition of sinusoids or wavelets many alternatives are available. In addition, since dictionaries we are interested in are overcomplete, the decomposition is non-unique. This gives us the possibility of adaptation, choosing among many possible representations the one which best fits our purposes. On the other hand, it also requires more complex approximation techniques whose theoretical decomposition capacity and computational load have to be carefully studied. In general, we aim at representing a signal with few and meaningful components. If we are able to represent a piece of information by using only few elements, it means that such elements can capture its main characteristics, allowing to compact the energy carried by a signal into the smallest number of terms. In such a framework, this work also proposes analysis methods which deal with the goal of considering the a priori information available when decomposing a structured signal. Indeed, a natural signal is not only an array of numbers, but an expression of a physical event about which we usually have a deep knowledge. Therefore, we claim that it is worth exploiting its structure, since it can be advantageous not only in helping the analysis process, but also in making the representation of such information more accessible and meaningful. The study of an adaptive image representation inspired and gave birth to this work. We often refer to images and visual information throughout the course of the dissertation. However, the proposed approximation setting extends to many different kinds of structured data and examples are given involving videos and electrocardiogram signals. An important part of this work is constituted by practical applications: first of all we provide very interesting results for image and video compression. Then, we also face the problem of signal denoising and, finally, promising achievements in the field of source separation are presented
The Grey Zones of Classic Hodgkin Lymphoma
Simple Summary Classic Hodgkin lymphoma (CHL) is a well-defined lymphoid neoplasm with a minority of characteristic neoplastic cells of B cell origin, namely Hodgkin and Reed-Sternberg cells immersed in a rich reactive inflammatory infiltrate in the background. Although CHL has always been set apart from non-Hodgkin lymphomas, cases with morphological and phenotypic features intermediate between CHL and other lymphomas have been described. Whereas some of these lymphomas only represent morphological mimics, others exhibit mutational and gene expression profiles which overlap with CHL, indicating that these cases, frequently termed grey zone lymphomas, reside on the biological boundary between CHL and large B-cell lymphomas. In the present review, we aim to describe the current knowledge of these rare lymphomas, address diagnostic issues and summarize today's concepts on the classification of grey zone lymphomas and related tumors. Classic Hodgkin lymphoma (CHL) is a well-defined neoplasm characterized by the presence of a minority of pathognomonic Hodgkin and Reed-Sternberg (HRS) cells in a reactive inflammatory background. Although genotypically of B cell origin, HRS cells exhibit a downregulated B cell program and therefore are set apart from other B cell lymphomas in the current WHO classification. However, cases with morphological and phenotypic features overlapping with CHL have been recognized, and the category of B cell lymphoma-unclassifiable-with features intermediate between diffuse large B cell lymphoma (DLBCL) and CHL, also termed grey zone lymphoma, was first introduced into the WHO classification in 2008 as provisional entity. These cases, as well as others raising a differential diagnosis of CHL can present diagnostic problems, as well as therapeutic challenges. Whereas some of these lymphomas only represent biologically unrelated morphological mimics, others, especially mediastinal grey zone lymphoma, exhibit genetic and gene expression profiles which overlap with CHL, indicating a true biological relationship. In this review, we address areas of diagnostic difficulties between CHL and other lymphoma subtypes, discuss the biological basis of true grey zone lymphoma based on recent molecular studies and delineate current concepts for the classification of these rare tumors
Sparse Approximation by Linear Programming using an L1 Data-Fidelity Term
This paper studies the problem of sparse signal approximation over redundant dictionaries. Our attention is focused on the minimization of a cost function where the error is measured by using the L1 norm, giving thus less importance to outliers. We show a constructive equivalence between the proposed minimization problem and Linear Programming. A recovery condition is then provided and an example illustrates the use of such a technique for denoising
Small Rural Enterprises and Innovative Business Models: A Case Study of the Turin Area
Small businesses and farms are today struggling to find an innovative solution to a globalizing market and a challenging society. Among different aspects, small businesses, especially in rural areas, need to find a balance among tailor-made innovative solutions, specific customers engagement strategies, creative value creation solutions, and new business concepts able to reshape existing markets. In this study, 16 small enterprises of rural areas near Turin belonging to different sectors collaborated to co-create innovative business models. To guide this discussion through a sustainable innovation path, a territorial Living Lab set up the four macro-topics of the co-creation workshops linked to the United Nations’ Sustainable Development Goals. Innovative business ideas were elaborated through the Brainstorming and Business Model Canvas tool and data were examined with SWOT and cross-case analysis. The results of the workshops pointed out four different innovative business ideas elaborated by the entrepreneurs, all linked by the need to translate innovation into sustainable adaptive solutions to local specificities. This case study showed that a range of enabling factors, such as the creation of a shared vision among local actors, can be codified to clear barriers and/or create innovative business solutions linked to economic, environmental, and social sustainability in rural areas
Image compression using an edge adapted redundant dictionary and wavelets
Low bit rate image coding is an important problem regarding applications such as storage on low memory devices or streaming data on the internet. The state of the art in image compression is to use 2-D wavelets. The advantages of wavelet bases lie in their multiscale nature and in their ability to sparsely represent functions that are piecewise smooth. Their main problem on the other hand, is that in 2-D wavelets are not able to deal with the natural geometry of images, i.e they cannot sparsely represent objects that are smooth away from regular submanifolds. In this paper we propose an approach based on building a sparse representation of the edge part of images in a redundant geometrically inspired library of functions, followed by suitable coding techniques. Best N-terms non-linear approximations in general dictionaries is, in most cases, a NP-hard problem and sub-optimal approaches have to be followed. In this work we use a greedy strategy, also known as Matching Pursuit to compute the expansion. The residual, that we suppose to be the smooth and texture part, is then coded using wavelets. A rate distortion optimization procedure choses the number of functions from the redundant dictionary and the wavelet basis
Investigational Paradigms in Downscoring and Upscoring DCIS: Surgical Management Review
Counseling patients with DCIS in a rational manner can be extremely difficult when the range of treatment criteria results in diverse and confusing clinical recommendations. Surgeons need tools that quantify measurable prognostic factors to be used in conjunction with clinical experience for the complex decision-making process. Combination of statistically significant tumor recurrence predictors and lesion parameters obtained after initial excision suggests that patients with DCIS can be stratified into specific subsets allowing a scientifically based discussion. The goal is to choose the treatment regimen that will significantly benefit each patient group without subjecting the patients to unnecessary risks. Exploring the effectiveness of complete excision may offer a starting place in a new way of reasoning and conceiving surgical modalities in terms of “downscoring” or “upscoring” patient risk, perhaps changing clinical approach. Reexcison may lower the specific subsets' score and improve local recurrence-free survival also by revealing a larger tumor size, a higher nuclear grade, or an involved margin and so suggesting the best management. It seems, that the key could be identifying significant relapse predictive factors, according to validated risk investigation models, whose value is modifiable by the surgical approach which avails of different diagnostic and therapeutic potentials to be optimal. Certainly DCIS clinical question cannot have a single curative mode due to heterogeneity of pathological lesions and histologic classification
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