New species of the superfamily Euphthiracaroidea (Acari: Oribatida) from Madagascar and Tanzania

Five new species of the family Euphthiracaridae are described, identified and figured from the Afrotropical region: Oribotritia breviseta sp. nov. from Andasibe National Park of Madagascar; Acrotritia paraardua sp. nov. from Vohimana Experimental Reserve, Ambohitanely Special Reserve and Andasibe National Park of Madagascar; Acrotritia paradikra sp. nov. from Ranomafana National Park and Ankarafantsika National Park of Masagascar; Microtritia diaphoros sp. nov. from the Nguru Mountains of Tanzania; and Microtritia parahauseri sp. nov from the Uluguru Mountains of Tanzania. A comparison with the most closely related species of the genera Oribotritia, Acrotritia and Microtritia is also presented.

http://zoobank.org/urn:lsid:zoobank.org:pub:7965FE4C-0AF8-49C4-B894-75D4EFD049BB     

Electrical signals control wound healing through phosphatidylinositol-3-OH kinase-gamma and PTEN

Wound healing is essential for maintaining the integrity of multicellular organisms. In every species studied, disruption of an epithelial layer instantaneously generates endogenous electric fields, which have been proposed to be important in wound healing. The identity of signalling pathways that guide both cell migration to electric cues and electric-field-induced wound healing have not been elucidated at a genetic level. Here we show that electric fields, of a strength equal to those detected endogenously, direct cell migration during wound healing as a prime directional cue. Manipulation of endogenous wound electric fields affects wound healing in vivo. Electric stimulation triggers activation of Src and inositol-phospholipid signalling, which polarizes in the direction of cell migration. Notably, genetic disruption of phosphatidylinositol-3-OH kinase-gamma (PI(3)Kgamma) decreases electric-field-induced signalling and abolishes directed movements of healing epithelium in response to electric signals. Deletion of the tumour suppressor phosphatase and tensin homolog (PTEN) enhances signalling and electrotactic responses. These data identify genes essential for electrical-signal-induced wound healing and show that PI(3)Kgamma and PTEN control electrotaxis.     

Essential role for collectrin in renal amino acid transport

Angiotensin -converting enzyme 2 (ACE2) is a regulator of the renin angiotensin system involved in acute lung failure, cardiovascular functions and severe acute respiratory syndrome (SARS) infections in mammals. A gene encoding a homologue to ACE2, termed collectrin (Tmem27), has been identified in immediate proximity to the ace2 locus. The in vivo function of collectrin was unclear. Here we report that targeted disruption of collectrin in mice results in a severe defect in renal amino acid uptake owing to downregulation of apical amino acid transporters in the kidney. Collectrin associates with multiple apical transporters and defines a novel group of renal amino acid transporters. Expression of collectrin in Xenopus oocytes and Madin-Darby canine kidney (MDCK) cells enhances amino acid transport by the transporter B(0)AT1. These data identify collectrin as a key regulator of renal amino acid uptake.     

Phase-resolved measurements of stimulated emission in a laser

Lasers are usually described by their output frequency and intensity. However, laser operation is an inherently nonlinear process. Knowledge about the dynamic behaviour of lasers is thus of great importance for detailed understanding of laser operation and for improvement in performance for applications. Of particular interest is the time domain within the coherence time of the optical transition. This time is determined by the oscillation period of the laser radiation and thus is very short. Rigorous quantum mechanical models predict interesting effects like quantum beats, lasing without inversion, and photon echo processes. As these models are based on quantum coherence and interference, knowledge of the phase within the optical cycle is of particular interest. Laser radiation has so far been measured using intensity detectors, which are sensitive to the square of the electric field. Therefore information about the sign and phase of the laser radiation is lost. Here we use an electro-optic detection scheme to measure the amplitude and phase of stimulated radiation, and correlate this radiation directly with an input probing pulse. We have applied this technique to semiconductor quantum cascade lasers, which are coherent sources operating at frequencies between the optical (>100 THz) and electronic (<0.5 THz) ranges. In addition to the phase information, we can also determine the spectral gain, the bias dependence of this gain, and obtain an insight into the evolution of the laser field.     

TMEM70 mutations cause isolated ATP synthase deficiency and neonatal mitochondrial encephalocardiomyopathy

We carried out whole-genome homozygosity mapping, gene expression analysis and DNA sequencing in individuals with isolated mitochondrial ATP synthase deficiency and identified disease-causing mutations in TMEM70. Complementation of the cell lines of these individuals with wild-type TMEM70 restored biogenesis and metabolic function of the enzyme complex. Our results show that TMEM70 is involved in mitochondrial ATP synthase biogenesis in higher eukaryotes.