Sistema de criptografia simétrica via porta lógica quântica.

Atualmente, a teoria relacionada à criptologia é fortemente baseada na hipótese de unidirecionalidade de caminhos computacionais. Esta conjectura matemática sustenta que deve haver uma função bijetora para a qual o cálculo em uma direção é fácil, enquanto reconstruir o estado de entrada a partir do estado de saída é difícil - ?fácil? e ?difícil? devem ser entendidas no sentido de complexidade computacional.bitstream/item/138134/1/ComTec119-criptografia.pd

Protótipo de sistema de segurança criptográfica via porta lógica quântica.

O cifrador XOR não é considerado completamente seguro, pois não há chaves de criptografia verdadeiramente aleatórias, dado que as chaves são geradas em geradores de números pseudorrandômicos a partir de sementes que não podem ser negligenciadas. No entanto, uma chave que destrói a própria semente que a gerou, pode ser considerada verdadeiramente aleatória, pois o seu estado inicial é definitivamente ignorado. Neste trabalho, nós apresentamos um modelo de chaves verdadeiramente aleatórias que podem ser obtidas a partir da porta quântica denominada controlled-NOT (CNOT) usada para emaranhar estados EPR

Uso do R na implementação de um modelo baseado no indivíduo para simular a dinâmica de propagação do HLB do citros.

RESUMO - A citricultura mundial tem sido afetada pela doença conhecida como Huanglongbing (HLB), considerada a mais séria por trazer grandes prejuízos aos citricultores e não possuir cura até o momento. No Brasil, o inseto-vetor responsável por transmitir a doença é o psilídeo Diaphorina citri. Estudos sobre a dinâmica de propagação da doença vem sendo desenvolvidos no âmbito do projeto HLB-BioMath2. Este trabalho apresenta uma implementação em R e Shiny de um modelo baseado no indivíduo (MBI) para estudar a dinâmica espaço-temporal do HLB no Recôncavo baiano. As simulações têm permitido observar o rápido espalhamento da doença pelos pomares, devido à grande capacidade de migração do inseto e ao grande período de incubação da doença nas plantas de citros. O simulador encontra-se em desenvolvimento e tem sido observada a necessidade de otimização do código-fonte pois, devido às características do MBI, o tempo de execução no R é um fator importante a ser observado.CIIC 2017. Nº 17604

Protocolo para cifra de uso único via função NOT controlada.

Resumo ? Criptografia é uma técnica de proteção da informação que consiste em codificar o conteúdo de uma mensagem por meio da utilização de algoritmos matemáticos a fim de criar padrões de segurança de armazenamento de dados e de gestão de tráfego entre dispositivos automatizados. Neste trabalho, é apresentado um protocolo de criptografia simétrica baseada em cifra de uso único One-Time Pad, (OTP) associada ao modo de operação Electronic Code Book (ECB). O protocolo consiste em um algoritmo que divide a mensagem original em blocos, e cada bloco é criptografado separadamente combinando caractere por caractere da mensagem original a uma chave criptográfica aleatória que é utilizada apenas uma vez para garantir que o sistema seja imperscrutável. A chave criptográfica é obtida por meio da porta lógica Controlled-NOT gate (CNOT) para alcançar um texto cifrado seguro.bitstream/item/175197/1/Boletim43.pd

Protocolo de criptografia simétrico baseado em permutações unidirecionais.

Neste artigo, um protocolo de criptografia simétrica utilizando o conceito de permutação unidirecional é apresentado. Os resultados mostram que a probabilidade de inversão da primitiva criptográfica se aproxima de zero mais rápido que o recíproco de um polinômio positivo indicando que uma permutação unidirecional é um gerador eficaz de (pseudo) aleatoriedade e pode ser utilizada na construção de um sistema de criptografia seguro

Especificação e instanciação de modelos matemáticos hierárquicos utilizando XML no framework de simulação MaCSim.

A equipe do Laboratório de Matemática Computacional da Embrapa Informática Agropecuária optou pela metalinguagem Extensible Markup Language (XML), para desenvolver um padrão de especificação de modelos atômicos e hierárquicos para o framework de simulação MaCSim.SBIAgro 2015

Epidemiology, practice of ventilation and outcome for patients at increased risk of postoperative pulmonary complications

BACKGROUND Limited information exists about the epidemiology and outcome of surgical patients at increased risk of postoperative pulmonary complications (PPCs), and how intraoperative ventilation was managed in these patients. OBJECTIVES To determine the incidence of surgical patients at increased risk of PPCs, and to compare the intraoperative ventilation management and postoperative outcomes with patients at low risk of PPCs. DESIGN This was a prospective international 1-week observational study using the ‘Assess Respiratory Risk in Surgical Patients in Catalonia risk score’ (ARISCAT score) for PPC for risk stratification. PATIENTS AND SETTING Adult patients requiring intraoperative ventilation during general anaesthesia for surgery in 146 hospitals across 29 countries. MAIN OUTCOME MEASURES The primary outcome was the incidence of patients at increased risk of PPCs based on the ARISCAT score. Secondary outcomes included intraoperative ventilatory management and clinical outcomes. RESULTS A total of 9864 patients fulfilled the inclusion criteria. The incidence of patients at increased risk was 28.4%. The most frequently chosen tidal volume (VT) size was 500 ml, or 7 to 9 ml kg1 predicted body weight, slightly lower in patients at increased risk of PPCs. Levels of positive end-expiratory pressure (PEEP) were slightly higher in patients at increased risk of PPCs, with 14.3% receiving more than 5 cmH2O PEEP compared with 7.6% in patients at low risk of PPCs (P < 0.001). Patients with a predicted preoperative increased risk of PPCs developed PPCs more frequently: 19 versus 7%, relative risk (RR) 3.16 (95% confidence interval 2.76 to 3.61), P < 0.001) and had longer hospital stays. The only ventilatory factor associated with the occurrence of PPCs was the peak pressure. CONCLUSION The incidence of patients with a predicted increased risk of PPCs is high. A large proportion of patients receive high VT and low PEEP levels. PPCs occur frequently in patients at increased risk, with worse clinical outcome

Epidemiology, practice of ventilation and outcome for patients at increased risk of postoperative pulmonary complications: LAS VEGAS - An observational study in 29 countries

BACKGROUND Limited information exists about the epidemiology and outcome of surgical patients at increased risk of postoperative pulmonary complications (PPCs), and how intraoperative ventilation was managed in these patients. OBJECTIVES To determine the incidence of surgical patients at increased risk of PPCs, and to compare the intraoperative ventilation management and postoperative outcomes with patients at low risk of PPCs. DESIGN This was a prospective international 1-week observational study using the ‘Assess Respiratory Risk in Surgical Patients in Catalonia risk score’ (ARISCAT score) for PPC for risk stratification. PATIENTS AND SETTING Adult patients requiring intraoperative ventilation during general anaesthesia for surgery in 146 hospitals across 29 countries. MAIN OUTCOME MEASURES The primary outcome was the incidence of patients at increased risk of PPCs based on the ARISCAT score. Secondary outcomes included intraoperative ventilatory management and clinical outcomes. RESULTS A total of 9864 patients fulfilled the inclusion criteria. The incidence of patients at increased risk was 28.4%. The most frequently chosen tidal volume (V T) size was 500 ml, or 7 to 9 ml kg−1 predicted body weight, slightly lower in patients at increased risk of PPCs. Levels of positive end-expiratory pressure (PEEP) were slightly higher in patients at increased risk of PPCs, with 14.3% receiving more than 5 cmH2O PEEP compared with 7.6% in patients at low risk of PPCs (P ˂ 0.001). Patients with a predicted preoperative increased risk of PPCs developed PPCs more frequently: 19 versus 7%, relative risk (RR) 3.16 (95% confidence interval 2.76 to 3.61), P ˂ 0.001) and had longer hospital stays. The only ventilatory factor associated with the occurrence of PPCs was the peak pressure. CONCLUSION The incidence of patients with a predicted increased risk of PPCs is high. A large proportion of patients receive high V T and low PEEP levels. PPCs occur frequently in patients at increased risk, with worse clinical outcome.</p

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P &lt; 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P &lt; 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223