Lo studio della cinematica articolare del ginocchio protesizzato, a distanza di più di 70 anni dai primi interventi di artroprotesi dell’articolazione, rappresenta, ancora oggi, un campo di ricerca di estremo interesse ed in continua evoluzione e valutazione sia dal punto di vista ortopedico che ingegneristico. Diverse tecniche sono descritte in letteratura per valutare la biomeccanica della protesi come la chirurgia assistita da navigatore, ma la recente tecnologia “RSA”, sviluppata nel 1972 a Lund (Svezia), risulta la più accurata. Nella seguente dissertazione, redatta in collaborazione con il gruppo di ricerca del Laboratorio di Biomeccanica e Innovazione Tecnologica dell’Istituto Ortopedico Rizzoli di Bologna e dall’Università di Bologna, è stato studiata, in vivo e sotto carico, la cinetica articolare del ginocchio protesizzato attraverso il suo studio cinematico intraoperatorio mediante navigatore e post-operatorio mediante tecnica RSA a 2,5 anni di follow up. Il protocollo di studio comprendeva una valutazione cinematica intraoperatoria, un valutazione clinica ed una valutazione radiologica post-operatoria tramite tecnica RSA dinamica effettuata presso gli ambulatori dell’Istituto Ortopedico Rizzoli di Bologna. La valutazione intraoperatoria è stata effettuata utilizzando un sistema di chirurgia navigata, la valutazione clinica, composta da un esame obiettivo ortopedico ed un questionario, ha permesso di ottenere dati utili alla costruzione di score quali Knee Society Score clinico (KSSc), Knee Society Score funzionale (KSSf) e VAS ed infine la valutazione radiografica post-peratoria è stata condotta mediante l’utilizzo di un macchinario per RSA dinamica e si è avvalsa di un software dedicato. Scopo dello studio è stato quello di analizzare la cinematica intra operatoria mediante il sistema di navigazione e la cinematica post-operatoria mediante tecnica di RSA dinamica durante l’esecuzione di comuni task motori quali discesa di uno scalino, alzata dalla sedia e passo e di correlare i dati intraoperatori con quelli post-operatori ottenuti. / The study of the joint kinematics of the knee prosthesis, after more than 70 years from the first measures of joint arthroplasty, is still today a very interesting research field in continuous evolution and evaluation both from an orthopedic and engineering point of view. Several techniques are described in the literature to evaluate the biomechanics of the prosthesis as a navigator assisted surgery, but the recent "RSA" technology, developed in 1972 in Lund (Sweden), is the most accurate. In the following essay, written in collaboration with the research group of the Laboratory of Biomechanics and Innovation Technological Rizzoli Orthopaedic Institute of Bologna and the University of Bologna, he has been studied in vivo and under load, the prosthetic knee joint kinetics through its kinematic study using intraoperative navigation system and postoperative using RSA technique to 2.5 years of follow up. The study protocol included a kinematics intraoperative assessment, a clinical evaluation and postoperative radiographic evaluation performed by RSA dynamic technique at the clinics Rizzoli Orthopaedic Institute of Bologna. The intraoperative evaluation was performed using a navigated surgery system, clinical assessment, consisting of an orthopedic physical examination and a questionnaire, it has resulted in data useful to the construction of a clinical score as Knee Society Score (KSSC), functional Knee Society Score (KSSf) and VAS and finally the post-postoperative radiographic evaluation it was conducted through the use of a machine for RSA dynamic and has made use of a dedicated software. Aim of the study was to analyze the kinematic operating intra using the navigation system and the postoperative kinematics using RSA dynamic technique when performing common tasks such engines descent stepped, got up from the chair and step and to correlate intraoperative data with post-operative obtained.

Introduction: Open fractures of the leg represent a severe trauma. The combined approach, shared between plastic and orthopaedic surgeons, is considered to be important, although this multidisciplinary treatment is not routinely performed. Aim of this study was to verify whether the orthoplastic treatment is of any advantage over the traditional simply orthopedic treatment, through a multicentric inclusion of these unfrequent injuries into a prospective study. Material and methods: The following trauma centres were involved: Rizzoli Orthopaedic Institute/University of Bologna (leading centre) and Maggiore Hospital (Bologna, Italy), Frenchay Hospital (Bristol, United Kingdom), Jinnah Hospital (Lahore, Pakistan). All patients consecutively hospitalized in the mentioned centres between January 2012 and December 2013 due to tibial open fractures were included in the study and prospectively followed up to December 2014. Demographics and other clinical features were recorded, including the type of treatment (orthopaedic or orthoplastic). The considered outcome measures included duration of hospitalization, time for bone union and soft tissue closure, Enneking score at 3, 6 and 12 months, the incidence of osteomyelitis and other complications. Results: A total of 164 patients were included in the study. Out of them 68% were treated with an orthoplastic approach, whereas 32% received a purely orthopedic treatment. All considered outcome measures showed to be improved by the orthoplastic approach, compared to the orthopaedic one: time for soft tissue closure (2 versus 25 weeks), duration of hospital stay (22 versus 55 days), time for bone union (6 versus 8.5 months) , number of additional operations (0.6 versus 1.2) and functional recovery of the limb at 12 months (27 versus 19, Enneking’s score). All results were statistically significant. Conclusion: The combined orthoplastic approach to the treatment of open tibia fractures, in particular for high grade injuries (Gustilo 3B), is proven to improve the outcome of these severe injuries.

Lo scopo di questo studio è stato quello di determinare se a lungo termine le concentrazioni sieriche di ioni nei pazienti con protesi di rivestimento d’anca metallo-metallo (MOM-HR, metal-on-metal hip resurfacing) fossero differenti da quelle valutate nei pazienti con protesi totale d’anca metallo-metallo e testa del diametro di 28 mm (MOM-THA, metal-on-metal total hip arthroplasty); inoltre è stato valutato se le concentrazioni ioniche fossero al di sopra dei valori di riferimento e se fosse possibile stabilire l’esistenza di una relazione tra sesso e concentrazioni di ioni con riferimento al tipo di impianto. Il gruppo MOM-HR era costituito da 25 pazienti mentre il gruppo MOM-THA era di 16 pazienti. Per poter ricavare i valori di riferimento sono stati reclutati 48 donatori sani. La misurazione delle concentrazioni degli ioni cobalto (Co), cromo (Cr), nickel (Ni) e molibdeno (Mo) è stata effettuata utilizzando la spettrofotometria ad assorbimento atomico su fornace di grafite. A parte il Ni, le concentrazioni di ioni nei pazienti con MOM-HR erano più elevate rispetto ai controlli. Il rilascio di ioni Cr e Co nei pazienti con MOM-HR è risultato superiore rispetto ai soggetti con MOM-THA. Da un’analisi basata sul sesso, è emerso che nelle femmine con MOM-HR i livelli di ioni Cr e Co sono risultati significativamente aumentati rispetto alle femmine con MOM-THA. Indipendentemente dal tipo di impianto, gli accoppiamenti metallo-metallo (MOM) producono concentrazioni di ioni metallici significativamente più alte a follow-up a lungo termine rispetto a quelle osservate nei soggetti sani. Un fattore che deve essere attentamente considerato nella scelta dell’impianto, e in particolar modo nei soggetti giovani, è il cospicuo rilascio di ioni Cr e Co nella popolazione femminile con MOM-HR. / The purpose of this study was to determine if long-term serum ion concentrations in patients with metal-on-metal hip resurfacing were different from those assessed in patients with metal-on-metal total hip arthroplasty; moreover we evaluated whether these concentrations would be above the reference values and whether a relation between gender and ion concentrations with regards to implant type was present. Twenty-five and sixteen patients constituted MOM-HR and MOM-THA groups, respectively. Forty-eight healthy donors were recruited for reference values. Cobalt, chromium, nickel and molybdenum were measured by furnace graphite atomic absorption spectrofotometry. Except nickel, ion concentrations in MOM-HR patients, were higher than in controls. Chromium and cobalt release in MOM-HR were higher than in MOM-THA subjects. A gender-based analysis, showed that in MOM-HR females chromium and cobalt were significantly increased compared to MOM-THA ones. Regardless of implant type MOM couplings produce significantly higher metal ion concentrations at the long-term follow-up than those observed in healthy subjects. The conspicuous release of chromium and cobalt in the female MOM-HR population should be carefully considered during implant selection, particularly in young subjects.

Background Scopo del progetto di ricerca è valutare se l'utilizzo della core decompression associata a medicina rigenerativa (gel piastrinico, concentrato midollare autologo e matrice ossea demineralizzata) è sicuro ed efficace nel trattamento dell'osteonecrosi della testa del femore, anche per gli stadi più avanzati Materiali e metodi Inclusi in due protocolli di ricerca (ON-08 e AVN-13) sono stati trattati più di 50 pazienti, dei quali 29 con adeguato follow up (29 anche trattate). Nella stessa procedura il midollo osseo viene aspirato e concentrato, poi si procede alla core decompression ed il materiale rigenerativo (demineralizzato, concentrato midollare e gel piastrinico) vengono introdotti all'interno della lesione con approccio mini invasivo. I pazienti vengono poi valutati clinicamente e con radiografie standard e risonanza magentica nucleare ogni 3 mesi. L'outcome primario è stato valutare la sopravvivenza al trattamento (intesa come non conversione in artroprotesi) mentre gli obiettivi secondari sono stati la valutazione dei sintomi (dolore), della clinica (funzione) e la valutazione degli esami strumentali. Results La progressione radiografica è stata riscontrata in 7 anche. Complicazioni in 2 pazienti (una frattura ed una infezione). 16 anche hanno invece riportato risultati buoni o eccellenti con HHS > 80 a 2 anni di follow up. La protesi è stata indicata in 8 casi (27%). Nei casi falliti, lo stadio di nerosi era IIB in 6 e IIA in uno, mentre stadio III in 2 pazienti. Conclusioni I risultati preliminari sono promettenti in quanto sovrapponibili a quelli disponibili in letteratura. In particolare ottimi risultati clinico-funzionali nei pazienti giovani, affetti da neoplasie ematologiche. Ad ogni modo, è necessario un follow up maggiore ed una corte più ampia di pazienti per confermare i buoni risultati ottenuti. / Background We aim to assess whether the use of core decompression and the application of autologous bone marrow concentrate (BMC) along with demineralized bone matrix (DBM) and Platelet Rich Fibrin (PRF) in the treatment of osteonecrosis of the femoral head (ONFH) is safe and effective and whether this technique is indicated in advanced stages. Methods Twenty-nine patients (30 hips) were enrolled in this clinical trial at the Rizzoli Orthopaedic Institute. In the same procedure bone marrow was aspirated and concentrated, then core decompression was performed and BMC mixed with DBM and PRF was introduced into the lesion. Patients were assessed postoperatively with X-Ray and MRI. Primary outcome was the survival rate of hips not converted to total hip arthroplasty (THA). The secondary outcomes were radiographic evolution and clinical symptoms evaluated with Harris Hip Score (HHS). Results Radiographic progression was found in 7 hips. There were complications in 2 hips (one fracture and one deep infection). Sixteen hips with successful treatment had good to excellent functional results at 2-year follow-up (HHS > 80). THA were indicated in 8 hips (27%). In failed cases, the Ficat stage was IIB in 6 and 1 IIA and III respectively in the other two patients. Conclusions The early outcomes of our procedure are similar compared to the literature with promising results in post collapse stages, particularly in young patients treated for haematological malignancies. However, a longer follow-up and more selective study criteria are needed to confirm the present data

Autologous bone grafting is a standard procedure for the clinical repair of skeletal defects, and good results have been obtained. Autologous vascularized bone grafting and allografts are often used, presenting several drawbacks. On the other side, several studies in literature reported the ability of bone marrow derived cells to promote neo-vascularization thanks to specific GF, hematopoietic and nesenchymal stem cells. In this scenario a new procedure was developed, consisting in an allogenic bone graft transplantation in a critical size defect in rabbit radius, plus a deviation at its inside of the median artery and vein with a supplement of autologous bone marrow concentrate on a collagen scaffold. Twenty-four rabbits were were operated with different experimental and control procedures. For each group, 3 experimental times: 8, 4 and 2 weeks. An in vitro evaluation of bone marrow concentrate was performed and at the time of sacrifice histological and histomorphometrical assessment were performed with immunohistochemical assays for VEGF, CD31 e CD146 to highlight the presence of vessels and endothelial cells. Micro-CT Analysis with quantitative bone evaluation was performed. The bone marrow concentrate showed a marked capability to differentiate into osteogenic, chondrogenic and agipogenic lineages. No complications were reported. The bone grafts showed only a partial integration, mainly at the extremities in the group with vascular and bone marrow concentrate supplement. Immunohistochemistry showed an interesting higher VEGF expression in the same group. Micro CT analysis showed a higher remodeling activities in the groups treated with vascular supplement, with an area of integration at the extremities increasing with the extension of the sacrifice time. The present study suggests that the vascular and marrow cells supplement may positively influence the neoangiogenesis and the neovascularization of the homologous bone graft.

The aim of our RCT was to evaluate safety and efficacy of a new device called Prevention Nail System (PNS) developed for the prevention of femoral neck fractures (FNFs) in patients with severe osteoporosis. The PNS is a titanium screw with a hydroxyapatite coating implanted in the femoral neck in order to reinforce it. We enrolled patients with: FNF; age ≥65 years; DXA of the noninjured hip with a T-score ≤ −2.5 SD. In the fractured hip patients received standard treatment while the contralateral hip was randomized either to receive PNS (group A) or not: control group (B). During each follow-up (FU) at 3, 12 and 24 months, DXA, CT and X-rays of the reinforced hip were performed. The mean age was 83 years and the preoperative DXA was −3.3 SD in both groups. The walking ability of patients with PNS were comparable to controls. The CT scan showed good integration of the PNS in the bone. At the longest available FU 23 patients reported one or more falls. 16 nonfemoral fractures were recorded: 10 (A) and 6 (B) and 6 contralateral hip fractures (CHFs): 3 in the PNS group and 3 in the control group. In A all CHFs occurred within 1 month after surgery and there was a difficult screw placement during surgery, in the control group the CHFs were consequence of a fall (6 months to 2 years after the first FNF). No statistical differences were reported between groups A and B. In conclusion, the device was well tolerated; CHFs in the PNS group should be considered a technical error due to the surgical instruments. Safety of the device can be increased by improving the instruments to reduce the risk of iatrogenic fractures.

Introduzione: Scopo dello studio è stato analizzare i risultati oncologici e funzionali di un’ampia casistica multicentrica di pazienti trattati chirurgicamente per condorsarcoma (CS) della pelvi. Materiali e metodi: La casistica comprende 309 pazienti trattati nel periodo 1975-2013: 193 uomini (63%) e 116 donne (37%) con un età media di 46,4 anni (15-81 anni). I CS erano centrali in 136 casi (34 grado 1; 83 grado 2; 19 grado 3), periferici in 109 (60 grado 1; 47 grado 2; 2 grado 3), dedifferenziati in 36, a cellule chiare in 4, mesenchimali in 2 e periostei in 3, mentre in 19 casi non era nota la variante istologica. Il tumore aveva una localizzazione di tipo I in 74 casi, I-IV in 13, I-II in 39, II-III in 57, III in 35, II in 42 e I-II-III in 49 casi. Un’amputazione interileoaddominale è stata effettuata in 49 pazienti (16%), mentre 260 (84%) sono stati trattati conservativamente: 144 resezioni senza ricostruzione e 116 resezioni con ricostruzione. Margini ampi in 212 casi, ampi contaminati in 23, marginali in 50 ed intralesionali in 24 casi. Risultati: La sopravvivenza a 10 e 15 anni è stata rispettivamente del 73% e 70%. Ad un follow-up medio di 9 anni (range 2-32 anni), 188 pazienti (61%) risultavano continuativamente liberi da malattia, 28 liberi dopo trattamento di recidiva locale (9%), 54 (17%) deceduti per malattia, 13 (4%) deceduti per altre cause e 26 (8%) vivi con malattia. L’alto grado istologico ed il sottotipo dedifferenziato correlano significativamente con peggior prognosi (p<0,0001). All’analisi multivariata sulla sopravvivenza, stadio e grado influenzano significativamente la prognosi. L’incidenza di recidiva locale è stata del 27,8% (86 pazienti). Conclusioni: La chirurgia conservativa è il trattamento “gold standard”. La localizzazione acetabolare pone importanti difficoltà tecniche per la ricostruzione. C’è una correlazione significativa tra grado tumorale e sopravvivenza. / Introduction. Aim of this study was to review the long-term oncologic and functional outcome of surgical management in a large series of patients with pelvic chondrosarcoma (CS). Material and Methods. We analyzed 309 patients treated between 1975-2013: 193 males (63%) and 116 females (37%) with a mean age of 46.4 years (range, 15-81 years). There were 136 central CSs (34, 83 and 19 cases grade 1, 2 and 3 respectively), 109 peripheral CSs (60, 47 and 2 cases grade 1, 2 and 3), 36 dedifferentiated CSs, 4 clear cell CSs, 2 mesenchymal CSs and 3 periosteal CSs, 19 otherwise defined CSs. Tumor site was classified as type I in 74 cases, I-IV in 13, I-II in 39, II-III in 57, III in 35, II in 42 and I-II-III in 49 cases. Forty-nine patients had an external hemipelvectomy (16%), whereas 260 patients (84%) underwent a limb-salvage procedure: 144 resections without reconstruction and 116 resections with reconstruction. Margins were wide in 212 cases, wide but contaminated in 23, marginal in 50 and intralesional in 24 cases. Results. Survival on Kaplan Meier curve was 73% and 70% at 10 and 15 years respectively. At a mean of 9 years (1 to 32 years), 188 patients (61%) were continuously NED, 28 were NED after treatment of local recurrence (9%), 54 (17%) DWD, 13 (4%) died of other causes and 26 (8%) AWD. In central and peripheral CSs, high-grade tumors correlated with worse survival. Dedifferentiated CS had a significantly worst prognosis (p<0.0001). At multivariate analysis on survival, stage and grade statistically influenced prognosis. Overall incidence of local recurrence was 27.8% (86 patients). Conclusions. Surgery is the mainstay of treatment for pelvic CS. CSs with acetabular involvement offer challenging technical problems to reliable and lasting reconstruction. There was a significant correlation between histologic grade and survival.

Ce travail de thèse présente le développement de modèles numériques pour la modélisation de l’endommagement des matériaux composites à fibres continues et matrice polymère. L’objectif est de fournir des outils numériques efficaces pour prédire l’endommagement sous chargement monotone et cyclique. Deux modèles ont été développés, un basé sur une approche multi-échelle d’homogénéisation et l’autre défini dans le cadre de la mécanique de l’endommagement. Ce dernier est utilisé dans une nouvelle approche pour prédire la durée de vie des matériaux composites. La première approche est une méthode multi-échelle afin d’étudier l’influence de l’endommagement à l’échelle microscopique sur le comportement macroscopique du composite. Le comportement macroscopique est déterminé par homogénéisation d’une cellule unitaire. L’approche est appliquée au cas d’un composite unidirectionnel afin d’étudier l’influence de l’endommagement de la matrice. Pour contourner les difficultés d’une approche multi-échelle, un modèle mésoscopique basé sur le couplage entre la plasticité et l’endommagement est proposé. Le modèle est validé et confronté à d’autres modèles ainsi qu’à des résultats expérimentaux. La dernière contribution est le développement d’une nouvelle approche pour la prédiction de la durée de vie des matériaux composites s’appuyant sur l’hypothèse que le matériau atteint un état stabilisé d’endommagement. Cette hypothèse permet d’utiliser l’analyse simplifiée pour prédire les états stabilisés. Le modèle de fatigue proposé est une loi puissance entre le nombre de cycles et les forces thermodynamiques associées à l’endommagement. L’approche est validée à partir de résultats expérimentaux. / A numerical framework for the modeling of the damage in fibre reinforced polymer composite materials has been developped. The objectives were to provide efficient numerical tools to predict the damage under static and cyclic loading. Two different models were proposed, one based on a fully computational multi-scale homogenization technique and a second one under the hypothesis of the meso-mechanics associated with a coupled damage-plastic constitutive model. The latter has been used in a new approach developped to predict the life of composite structures. As a first approach, a multi-scale application has been developed to better understand the influence of the damages occuring at lower scales on the macroscopic response. The macroscopic is defined by homogenization of a unit cell. The scheme is used to analyze the effect of the matrix damage on the material response in the case of unidirectional composites. To overcome the difficulties of the multi-scale approach, a meso-scale phenomenological model based on the coupled plasticity with continuous damage mechanics is proposed. All comparisons of the simulation with experiments and other models have shown good agreements. The third contribution is the development of a new approach to predict the life of composite materials based on the assumption that the material reaches a damage stabilized state during his life. This assumption makes it possible to use the simplified analysis. The life of the material is considered depending on the level of the thermodynamical forces associated with damage at the stabilized state by the use of a power law. Good agreements are obtained with experimental results.

IL-33 participa em diversas doenças com funções pró-inflamatórias e protetoras, de acordo com o contexto do microambiente. Com relação a biologia tumoral, o papel de IL-33 ainda é controverso. Estudos demonstraram que IL-33 possui efeitos pró e anti-inflamatórios em diferentes modelos animais de câncer. A presença desta citocina no estroma favorece a imunossupressão pela ativação de células T reguladoras e células mieloides supressoras. IL- 33 pode em outras situações promover a imunogenicidade e a resposta imune antitumoral de tipo 1 através das células T citotóxicas e células Natural Killers. Contudo o efeito preciso de IL-33 em diferentes tipos de câncer permanece incerto. Sendo assim, compreender o papel de IL-33 na imunobiologia do câncer, poderia direcionar esta citocina como um possível alvo em imunoterapias contra o câncer. Considerando, portanto, a pluralidade desta citocina no desenvolvimento de uma resposta imune, no presente estudo buscamos avaliar os efeitos do tratamento com anti-IL-33 em modelo experimental de carcinoma espinocelular de pele em camundongos BALB/c de linhagem selvagem. Ao final dos protocolos de indução e tratamento, a análise histopatológica revelou que o tratamento com anti-IL-33 levou a menor incidência de carcinoma espinocelular in situ e diminuição das atipias celulares e, consequentemente, do grau de displasia. O tratamento com anti-IL-33 levou a aumento nos percentuais de células B e diminuição nas percentagens de linfócitos T CD4+, células dendríticas, células TREG e macrófagos isolados do microambiente tumoral. Ademais, o tratamento com anti-IL-33 levou a aumento na percentagem de linfócitos T CD4+ produtores de IFN- e menor percentagem de linfócitos T CD4+ e CD8+ produtores de IL-4 nos linfonodos. Em camundongos submetidos ao tratamento, observou-se menor produção de TGF- no microambiente tumoral, sem interferir de modo significativo com a produção de IFN-, IL-4, IL-10 e IL-17. Os nossos resultados indicam que o tratamento com anti-IL-33 poderia ser alvo de novos estudos em busca de estratégias terapêuticas para o carcinoma espinocelular de pele. / IL-33 participates in several diseases with pro-inflammatory and protective functions, according to the context of the microenvironment. Related to tumor biology, the role of IL-33 is still controversial. Studies have shown that IL-33 has pro and anti-inflammatory effects in different animal models of cancer. Its presence in the stromal and tumor serum increases the immunosuppression by the activation of regulatory T cells and myeloid-derived suppressor cells. On the other hand, the intracellular form in tumor cells promotes immunogenicity and the antitumor type 1 immune response through cytotoxic T cells and natural killer cells. However, the precise effect of IL-33 on cancer conditions remains uncertain. Thus, understanding its role in the immunobiology of cancer could target this cytokine as a marker in cancer immunotherapies. Considering, the range of IL-33 in the development of an immune response, this study aims to evaluate the effects of the anti-IL-33 treatment on wild type BALB/c mouse squamous cell carcinoma (SSCC) development. Histopathological analysis revealed that anti-IL-33 treatment decreased the dysplasia. In addition, anti-IL-33 treatment showed an increasing percentage of B cells and reduced the percentage of CD4+ T lymphocytes, dendritic cells, TREG cells and macrophages in the tumor microenvironment. In the lymph node, anti-IL-33 treatment induced a shift towards the TH1 type cytokine profile and reduced the percentage of IL-4 expressing CD4+ and CD8+ cells. Additionally, anti-IL-33 treatment showed a reduced TGF- production in the tumor microenvironment, but with no changes to the IFN-, IL-4, IL-10 e IL-17 production. Taken together these results indicate that anti-IL-33 treatment could be the subject of further studies of therapeutic strategies for squamous cell carcinoma of the skin.

To deepen understanding of the relation between economic development and energy demand, this study estimates the Engel curves that relate per-capita energy consumption in major economic sectors to per-capita GDP. Panel data covering up to 123 nations are employed, and measurement problems are treated both in dataset construction and in estimation. Time and country fixed effects are assumed, and flexible forms for income effects are employed. There are substantial differences among sectors in the structure of country, time, and income effects. In particular, the household sector's share of aggregate energy consumption tends to fall with income, the share of transportation tends to rise, and the share of industry follows an inverse-U pattern. / Includes bibliographical references (p. 15-16). / Abstract in HTML and technical report in HTML and PDF available on the Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change website (http://mit.edu/globalchange/www/)