Cilia hoist dust out of the lungs, propel sperm toward the egg, and enable us to catch the scent of fresh coffee. The structures also help some cells attach to their surroundings, Schouteden et al. reveal (1). A cilium is built around the axoneme, an internal shaft of microtubules that sprouts from a structure known as the basal body. Between the axoneme and the basal body lies the transition z...

The high water storage capacity of minerals in Earth's mantle transition zone (410- to 660-kilometer depth) implies the possibility of a deep H2O reservoir, which could cause dehydration melting of vertically flowing mantle. We examined the effects of downwelling from the transition zone into the lower mantle with high-pressure laboratory experiments, numerical modeling, and seismic P-to-S conv...

[1] Water enters the Earth’s mantle by subduction of oceanic lithosphere. Most of this water immediately returns to the atmosphere through arc volcanism, but a part of it is expected as deep as the mantle transition zone (410–660 km depth). There, slabs can be deflected and linger before sinking into the lower mantle. Because it lowers the density and viscosity of the transition zone minerals (...

The protein nephrocystin-4 (NPHP4) is widespread in ciliated organisms, and defects in NPHP4 cause nephronophthisis and blindness in humans. To learn more about the function of NPHP4, we have studied it in Chlamydomonas reinhardtii. NPHP4 is stably incorporated into the distal part of the flagellar transition zone, close to the membrane and distal to CEP290, another transition zone protein. The...

zones showed unstable results with an unacceptably high complication rate.1-3 This led to design of a 9.0 mm hyperopia ablation profile.4 Today, most laser manufacturers offer relatively large treatment zones for hyperopia. A 5.5 to 6.0 mm optical zone and 9.0 mm ablation zone diameter seems to be the current standard. Figure 1 shows some examples of nominal optical zone (OZ) and ablation zone ...

PURPOSE We determine whether biochemical prostate specific antigen (PSA) failure can be accurately predicted from preoperative serum PSA combined with 6 morphological variables from radical retropubic prostatectomy specimens in men with peripheral zone cancers. The unexpected limitation imposed by preoperative serum PSA on biochemical failure led us to compare peripheral zone to transition zone...

The Neuro Image Quiz, Answers T.P. Thomas P. Naidich Thomas P. Naidich, MD, Division of Neuroimaging, Children’s Memorial Hospital, 2300 Children’s Plaza, Chicago, IL 60614 (USA) These images demonstrate a well-circumscribed lobu-lated erosion of the anterior parietal bone, situated just posterior to the coronal suture. In this case the zone of transition from obviously normal bone to obviously...

Mutations in human CEP290 cause cilia-related disorders that range in severity from isolated blindness to perinatal lethality. Here, we describe a Chlamydomonas reinhardtii mutant in which most of the CEP290 gene is deleted. Immunoelectron microscopy indicated that CEP290 is located in the flagellar transition zone in close association with the prominent microtubule-membrane links there. Ultras...

Roots are very sensitive to hypoxia and adapt effectively to a reduced availability of oxygen in the soil. However, the site of the root where oxygen availability is sensed and how roots acclimate to hypoxia remain unclear. In this study, we found that the root apex transition zone plays central roles in both sensing and adapting to root hypoxia. The exposure of cells of the root apex to hypoxi...