Automatic Generation of Input Grammars Using Symbolic Execution

Invalid input often leads to unexpected behavior in a program and is behind a plethora of known and unknown vulnerabilities. To prevent improper input from being processed, the input needs to be validated before the rest of the program executes. Formal language theory facilitates the definition and recognition of proper inputs. We focus on the problem of defining valid input after the program has already been written. We construct a parser that infers the structure of inputs which avoid vulnerabilities while existing work focuses on inferring the structure of input the program anticipates. We present a tool that constructs an input language, given the program as input, using symbolic execution on symbolic arguments. This differs from existing work which tracks the execution of concrete inputs to infer a grammar. We test our tool on programs with known vulnerabilities, including programs in the GNU Coreutils library, and we demonstrate how the parser catches known invalid inputs. We conclude that the synthesis of the complete parser cannot be entirely automated due to limitations of symbolic execution tools and issues of computability. A more comprehensive parser must additionally be informed by examples and counterexamples of the input language

Association of Nurse-Physician Teamwork and Hospital Surgical Patient Mortality

Interest in the relationship between nurses and physicians has been increasing over the past few decades. Teamwork between the two disciplines was first studied in the 1970s and interest surged again in the 1980s, when evidence suggested that better teamwork saved more lives. This study presents a cross-sectional analysis linking 2006-2007 nurse survey data, hospital administrative data, and patient discharge data. The study sample comprised of 665 hospitals, 1,321,904 patients, and 29,391 nurses. Logistic regression models were used to assess the association between higher levels of nurse-physician teamwork and patient outcomes (30-day mortality and failure-to-rescue). Regression models were also used to examine whether any associations between nurse-physician teamwork and patient outcomes depends upon the level of other modifiable characteristics of hospital nursing (nurse staffing and education levels) in acute hospital settings. Final analysis revealed decreased odds of both 30-day mortality (OR = 0.943, 95% CI 0.930,0.958) and failure-to-rescue (OR = 0.939, 95% CI 0.925, 0.953) for surgical patients cared for in hospitals with better nurse reported nurse-physician teamwork, adjusting for hospital structural characteristics and patient characteristics. In addition, there was a significant interaction between nurse staffing and nurse-physician teamwork on surgical patient 30-day mortality, and failure-to-rescue rates. There was also a significant interaction between nurse education and nurse-physician teamwork on surgical patient 30-day mortality, and failure-to-rescue rates. Our analysis found a trend of decrease in odds of death and failure-to-rescue for hospitals with both higher nurse-physician teamwork scores and lower patient-per-nurse ratios. Similarly, there is a trend of a decrease in odds of death and failure-to-rescue in hospitals with higher nurse-physician teamwork scores and higher proportion of BSN educated nurses. In order for initiatives to improve interprofessional teamwork to have greater impact on patient outcomes, nurse staffing and nurse education need to be at sufficient levels

Changes in the intestinal microbiota after a short period of dietary over-indulgence, representative of a holiday or festival season

The effects on the intestinal microbiota of a short period of marginal over-eating, characteristic of holiday or festival periods, were investigated in a pilot study. Fourteen healthy male subjects consumed a diet rich in animal protein and fat for seven days. During this period, the subjects significantly increased their dietary energy, protein, carbohydrate and fat intakes by 56, 59, 53 and 58%, respectively (all P < 0.05). The mean weight gain of 0.27 kg was less than the expected 1 kg, but this was consistent with a degree of under-reporting on the baseline diet. Fluorescence in situ hybridisation analysis confirmed the relative stability of each individual’s faecal microbiota but showed considerable variations between them. The diet was associated with a significant increase in numbers of total faecal bacteria and the bacteroides group, as detected by the universal bacterial probe (DAPI) and Bacteroides probe (Bac 303), respectively. Overall, there was a decrease in numbers of the Lactobacillus/Enterococcus group (Lab 158 probe; 2.8 ± 3.0% to 1.8 ± 1.8%) and the Bifidobacterium group (Bif 164 probe; 3.0 ± 3.7% to 1.7 ± 1.2%), although there was considerable inter-individual variation. Analysis of the relative proportions of each bacterial group as a percentage of the subject’s total bacteria showed a trend for a change in the intestinal microbiota that might be considered potentially unhealthy

I Am vs. We Are:How Biospheric Values and Environmental Identity of Individuals and Groups Can Influence Pro-environmental Behaviour

Most research in environmental psychology is conducted in individualistic countries and focuses on factors pertaining to individuals. It is yet unclear whether these findings also apply to more collectivistic countries, in which group factors might play a prominent role. In the current paper, we test the individual-focused value-identity-behaviour pathway, in which personal biospheric values relate to pro-environmental actions via environmental self-identity, in an individualistic and a collectivistic country. Furthermore, we test in both countries, whether a new group-focused pathway also exists, in which group values relate to pro-environmental behaviour via environmental group-identity, particularly in collectivistic countries. Questionnaire studies were conducted among Dutch (N = 161) and Chinese (N = 168) students. Our results indicated that personal biospheric values, mostly via environmental self-identity, predict pro-environmental behaviour in both individualistic and collectivistic cultures. We also found initial support for our newly proposed value-identity-behaviour pathway at the group level, particularly in China. Yet, in both countries, the association between group-level variables and pro-environmental behaviour was weaker than for personal level variables, and partly overlapped with personal level variables. Our findings show the relevance of personal- and group-level factors in understanding pro-environmental behaviour in both individualistic and collectivistic countries, which has strong theoretical and practical implications, particularly for developing international strategies to promote pro-environmental actions across the world