The effectiveness of lane departure warning systems—A reduction in real-world passenger car injury crashes

Objective: The objective of this study was to estimate the safety benefits of in vehicle lane departure warning (LDW) and lane keeping aid (LKA) systems in reducing relevant real-world passenger car injury crashes.

Methods: The study used an induced exposure method, where LDW/LKA-sensitive and nonsensitive crashes were compared for Volvo passenger cars equipped with and without LDW/LKA systems. These crashes were matched by car make, model, model year, and technical equipment; that is, low-speed autonomous emergency braking (AEB) called City Safety (CS). The data were extracted from the Swedish Traffic Accident Data Acquisition database (STRADA) and consisted of 1,853 driver injury crashes that involved 146 LDW-equipped cars, 11 LKA-equipped cars, and 1,696 cars without LDW/LKA systems.

Results: The analysis showed a positive effect of the LDW/LKA systems in reducing lane departure crashes. The LDW/LKA systems were estimated to reduce head-on and single-vehicle injury crashes on Swedish roads with speed limits between 70 and 120 km/h and with dry or wet road surfaces (i.e., not covered by ice or snow) by 53% with a lower limit of 11% (95% confidence interval [CI]). This reduction corresponded to a reduction of 30% with a lower limit of 6% (95% CI) for all head-on and single-vehicle driver injury crashes (including all speed limits and all road surface conditions).

Conclusions: LDW/LKA systems were estimated to lower the driver injury risk in crash types that the systems are designed to prevent; that is, head-on and single-vehicle crashes. Though these are important findings, they were based on a small data set. Therefore, further research is desirable to evaluate the effectiveness of LDW/LKA systems under real-world conditions and to differentiate the effectiveness between technical solutions (i.e., LDW and LKA) proposed by different manufacturers.     

Multiple marker screen positivity in the presence of hydrops fetalis

Three cases of hydrops fetalis presented in the second trimester as screen-positive for Down syndrome using multiple maternal serum markers. One case was a karyotypically normal female; one case was a monosomy X (Turner syndrome); and one case was a trisomy 21 (Down syndrome). In each case, the maternal serum human chorionic gonadotrophin (hCG) was disproportionately elevated. These cases support the contention that hydrops fetalis of any aetiology may present as screen-positive when using multiple maternal serum markers for Down syndrome. Further cases will be necessary before it can be determined whether a disproportionately elevated hCG is predictive of hydrops.     

Spatial and temporal variation in the size at maturity of the western rock lobster Panulirus cygnus George

The sizes at which female and male western rock lobster Panulirus cygnus become mature were examined over 32 years from records at six localities along the coast of Western Australia. The size of males at maturity was estimated from a subset of these data by a morphometric and a physiological method, with both producing statistically similar results. Males were larger at first maturity than females at the same sites. For both sexes, the sizes at first maturity at each location correlated (P<0.05) with the mean annual water temperature at that location, decreasing from south to north along the mainland coast and being smallest at the offshore Abrolhos Islands. Smaller sizes at maturity were recorded for both sexes than have been published previously. One certain explanation for these differences is that management measures protecting females with ovigerous setae have distorted size compositions and the ratio of immature to mature females, thereby increasing the likelihood of capturing small mature females. However, these fishing effects cannot fully account for the progressive decline in CL₅₀ observed over the past 20 years. Other possible hypotheses considered include increases in water temperature over this period, as well as whether this change could be consistent with a genotypic response caused by the selective removal of large lobsters combined with high exploitation rates.     

The effect of larval and early adult experience on behavioural plasticity of the aphid parasitoid <Emphasis Type="Italic">Aphidius ervi</Emphasis> (Hymenoptera,Braconidae, Aphidiinae)

The relevance of the integration of preimaginal and eclosion experiences on the subsequent habitat preferences and mate finding by the adult has been rarely tested in holometabolous insects. In this work, the effect of larval and early adult experiences on the behavioural responses of adult males of the aphid parasitoid, Aphidius ervi, towards volatiles from the host–plant complex (HPC) and from conspecific females were evaluated. Two experience factors were considered: host diet (normal diet=ND; artificial diet=AD), and eclosion, i.e. extraction or non-extraction of the parasitoid larva from the parasitised aphid (extracted=EX; non-extracted=NE). Thus, four treatments were set up: ND/NE, ND/EX, AD/NE and AD/EX. Glass Y-tube olfactometers were used to investigate the responses of adult A. ervi males to the odour sources used. Males from the ND/NE treatment showed a shorter latency to the first choice of olfactometer arms, displayed a marked preference towards the HPC olfactometer arm, and spent more time in the HPC arm than males from the other treatments. Only the interaction of host diet and eclosion experiences proved to be relevant in explaining the differences in latency to first choice, time spent in olfactometers arms, and behaviours displayed in the olfactometer arms. These results show the importance of the integration of larval and eclosion experiences in the development of stereotyped responses of the adults. This process may involve memory retention from the preimaginal and emergence period, but further research is needed to disentangle the contribution of each stage. The response to conspecific females was much less affected by the treatments in relation to first arm choice and times in olfactometer arms, suggesting a pheromone-mediated behaviour, even though a prompter and more intense wing fanning courtship behaviour was registered in the ND/NE males compared to males from the AD/NE treatment. These results show that sexual behaviours are less affected by early experiences than behaviours related with finding a HPC for foraging or oviposition. Taken together, our results demonstrate for first time that larval and eclosion experiences affect in a differential way the early responses of the adult towards environment-derived cues and mate related cues.