A Gauge field Induced by the Global Gauge Invariance of Action Integral

As a general rule, it is considered that the global gauge invariance of an action integral does not cause the occurrence of gauge field. However, in this paper we demonstrate that when the so-called localized assumption is excluded, the gauge field will be induced by the global gauge invariance of the action integral. An example is given to support this conclusion.Comment: 13 pages. Some typing errors are corrected and the format is update

Improvement of intraoperative antibiotic prophylaxis in prolonged cardiac surgery by automated alerts in the operating room.

OBJECTIVE: To assess the impact of an automated intraoperative alert to redose prophylactic antibiotics in prolonged cardiac operations. DESIGN: Randomized, controlled, evaluator-blinded trial. SETTING: University-affiliated hospital. PATIENTS: Patients undergoing cardiac surgery that lasted more than 4 hours after the preoperative administration of cefazolin, unless they were receiving therapeutic antibiotics at the time of surgery. INTERVENTION: Randomization to an audible and visual reminder on the operating room computer console at 225 minutes after the administration of preoperative antibiotics (reminder group, n = 137) or control (n = 136). After another 30 minutes, the circulating nurse was required to indicate whether a follow-up dose of antibiotics had been administered. RESULTS: Intraoperative redosing was significantly more frequent in the reminder group (93 of 137; 68%) than in the control group (55 of 136; 40%) (adjusted odds ratio, 3.31; 95% confidence interval, 1.97 to 5.56; P < .0001). The impact of the reminder was even greater when compared with the 6 months preceding the study period (129 of 480; 27%; P < .001), suggesting some spillover effect on the control group. Redosing was formally declined for 19 of the 44 patients in the reminder group without redosing. The rate of surgical-site infection in the reminder group (5 of 137; 4%) was similar to that in the control group (8 of 136; 6%; P = .42), but significantly lower than that in the pre-study period (48 of 480; 10%; P = .02). CONCLUSION: The use of an automatic reminder system in the operating room improved compliance with guidelines on perioperative antibiotic prophylaxis

Use of secondary forests by understory birds in a fragmented landscape in central Amazonia

Rates of deforestation in the Brazilian Amazon have increased since 1991 and forecasts are not optimistic about the slowing of this process. Some authors believe that the Amazon may be experiencing a massive process of species extinction. However, the deforestation is accompanied by the expansion of secondary forests that are established in the abandoned areas. The trend is an increase in secondary forests cover, resulting in a mosaic of primary forest (FP) and fragments separated by an array of secondary forests (FS). In this scenario, the prediction of a massive extinction could be wrong if many species could survive in the secondary forests. To assess the importance of FS for the understory birds we sampled areas in regeneration and a continuous forest of a fragmented landscape. We conducted mist netting (24 nets/day) for six consecutive days/month, for 8 months (May-November) in 2009. Some forest species as do not seem to be adapted to the secondary forest environment and their occurrences are restricted to continuous forest environments. But most focal species showed no significant difference in apparent survival rates between the enviroments, suggesting that these species inhabit the secondary forest and the primary forest similarly. Because most of the matrix in fragmented landscapes are composed by secondary forests, such results highlights the conservation value that these habitats present in the long term. Thus, FS should be regarded as dynamic matrix that not only allows the movement of individuals but also function as habitat for many species typical of FP.Na Amazônia, as taxas de desmatamento crescem desde 1991 e as previsões não são otimistas quanto à desaceleração desse processo. A devastação da floresta é acompanhada de uma expansão de florestas secundárias (FS) que se estabelecem nas áreas abandonadas. A tendência é um aumento de florestas secundárias, resultando num mosaico de floresta contínua e fragmentos separados por uma matriz de FS. Nesse cenário, autores acreditam que a Amazônia pode passar por um processo massivo de extinção de espécies. Por outro lado, a previsão de um processo massivo de extinção pode ser equivocada, pois muitas espécies florestais poderiam sobreviver nas florestas secundárias. Para avaliar o valor das florestas secundárias para espécies florestais amostramos por oito meses com redes de neblina uma capoeira (FS) em regeneração e uma floresta primária (FP) de uma paisagem fragmentada. Algumas espécies não foram capturadas na capoeira e aparentemente evitam esse tipo de hábitat. No entanto, a maioria das espécies do grupo focal não apresentou diferença na sobrevivência aparente entre os ambientes, o que nos indica que estão habitando a capoeira e a floresta primária da mesma forma. Na realidade amazônica, onde grande parte da matriz é composta por floresta secundária, a matriz tem valor para conservação e deve ser analisada como um elemento dinâmico que não apenas permite a movimentação de indivíduos, mas também serve de hábitat para muitas espécies de floresta primária. Mas ressaltamos que é fundamental a preservação de áreas de floresta primária que servirão de fonte às florestas secundárias adjacentes