Transgenerational inheritance of sexual attractiveness via small RNAs enhances evolvability in C. elegans.

It is unknown whether transient transgenerational epigenetic responses to environmental challenges affect the process of evolution, which typically unfolds over many generations. Here, we show that in C. elegans, inherited small RNAs control genetic variation by regulating the crucial decision of whether to self-fertilize or outcross. We found that under stressful temperatures, younger hermaphrodites secrete a male-attracting pheromone. Attractiveness transmits transgenerationally to unstressed progeny via heritable small RNAs and the Argonaute Heritable RNAi Deficient-1 (HRDE-1). We identified an endogenous small interfering RNA pathway, enriched in endo-siRNAs that target sperm genes, that transgenerationally regulates sexual attraction, male prevalence, and outcrossing rates. Multigenerational mating competition experiments and mathematical simulations revealed that over generations, animals that inherit attractiveness mate more and their alleles spread in the population. We propose that the sperm serves as a "stress-sensor" that, via small RNA inheritance, promotes outcrossing in challenging environments when increasing genetic variation is advantageous.

Blunt and penetrating injuries caused by rubber bullets during the Israeli-Arab conflict in October, 2000: a retrospective study.

BACKGROUND: Low-velocity rubber bullets were used by Israeli police to control riots by Israeli-Arabs in early October, 2000. We aimed to establish the factors that contribute to severity of blunt and penetrating injuries caused by these missiles. METHODS: We analysed medical records of 595 casualties admitted. We assessed relation of severity of injury to type of bullet, anatomical region of injury, and final outcome. Severity of injury was established by the abbreviated injury scale, and we calculated injury severity score. FINDINGS: 151 males and one female (age range 11-59 years) were included in the study, in whom 201 proven injuries by rubber bullets were detected. Injuries were distributed randomly over the body surface and were mostly located in the limbs (n=73), but those to the head, neck, and face (61), chest (39), back (16), and abdomen (12) were also frequently noted. 93 (61%) patients had blunt injuries and 59 (39%) penetrating ones. Severity of injury was dependent on ballistic features of the bullet, firing range, and anatomic site of impact. Two casualties died after a penetrating ocular injury into the brain and one died as a result of postoperative aspiration after a knee injury. INTERPRETATION: Resistance of the body surface at the site of impact (elastic limit) is the important factor that ascertains whether a blunt or penetrating injury is inflicted and its severity. Inaccuracy of rubber bullets and improper aiming and range of use resulted in severe injury and death in a substantial number of people. This ammunition should therefore not be considered a safe method of crowd control.