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Cytoplasmic cilia, a specialized type of cilia in which the axoneme resides within the cytoplasm rather than within the ciliary compartment, are proposed to allow for the efficient assembly of very long cilia. Despite being found diversely in male gametes (e.g., Plasmodium falciparum microgametocytes and human and Drosophila melanogaster sperm), very little is known about cytoplasmic cilia assembly. Here, we show that a novel RNP granule containing the mRNAs for axonemal dynein motor proteins becomes highly polarized to the distal end of the cilia during cytoplasmic ciliogenesis in Drosophila sperm. This allows for the incorporation of these axonemal dyneins into the axoneme directly from the cytoplasm, possibly by localizing translation. We found that this RNP granule contains the proteins Reptin and Pontin, loss of which perturbs granule formation and prevents incorporation of the axonemal dyneins, leading to sterility. We propose that cytoplasmic cilia assembly requires the precise localization of mRNAs encoding key axonemal constituents, allowing these proteins to incorporate efficiently into the axoneme. [ABSTRACT FROM AUTHOR]

Abstract  Unique types of textures and vortices of superfluid 3He in restricted geometries have been discussed. We investigated cw-NMR in rotating 3He A-phase in parallel plate geometries with gaps of 12.5 μm at 3.05 MPa. We observed a very sharp spectrum at rest which had shifted negatively as f=f L−0.93f A(T), where f A(T) is the full transverse dipole shift in A-phase. The large negative shift of 0.93f A(T) indicates that l ⊥ d. When we rotated the sample with rotation speed Ω faster than the critical Ω Fr, a new satellite signal appeared nearly at f L. The satellite signal intensity increased with increasing Ω, reached a maximum at Ω c and slowly decreased up to the maximum Ω of 2π rad/s. When Ω decreased from the maximum speed, the satellite signal rapidly decreased and disappeared at 5.5 rad/s down to zero rad/s. We measured the temperature dependence of the satellite signal intensity, Ω Fr and Ω c. We propose a model for the satellite signal, which is attributed to spin wave in Fréedericksz transition region induced by the counter flow. We also compare the satellite signal with Kee and Maki’s bound pair of HQV. [ABSTRACT FROM AUTHOR]

Proteins are expected to exhibit collective vibrational modes at terahertz frequencies. We have developed a promising approach to measure these motions by using a membrane device to hold samples. Samples of bovine serum albumin (BSA) in native and thermally denatured conformations were measured using terahertz time-domain spectroscopy. Clear differences were observed in transmittance and phase between native-conformation BSA samples and thermally denatured BSA samples. Time-domain data shows that samples exhibited relative time shifts when compared with a standard. Results suggest that there were differences in dielectric responses in the BSA samples, and these are probably associated with molecular conformational changes in the membrane device. [ABSTRACT FROM AUTHOR]

Whether DNA segregates in a biased way has been a subject of intense controversy and debate. Although highly provocative in its biological implications, if true, technical problems have limited researchers from drawing firm conclusions from the data. Elabd et al. (2013. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201307110/DC1) now show a high frequency of nonrandom template segregation during differentiation of embryonic stem cells using rigorous experimentation and implicate the methyltransferase Dnmt3 as a key regulator of this process. [ABSTRACT FROM AUTHOR]

Asymmetric stem cell division is a critical mechanism for balancing self-renewal and differentiation. Adult stem cells often orient their mitotic spindle to place one daughter inside the niche and the other outside of it to achieve asymmetric division. It remains unknown whether and how the niche may direct division orientation. Here we discover a novel and evolutionary conserved mechanism that couples cell polarity to cell fate. We show that the cytokine receptor homolog Dome, acting downstream of the niche-derived ligand Upd, directly binds to the microtubule-binding protein Eb1 to regulate spindle orientation in Drosophila male germline stem cells (GSCs). Dome's role in spindle orientation is entirely separable from its known function in self-renewal mediated by the JAK-STAT pathway. We propose that integration of two functions (cell polarity and fate) in a single receptor is a key mechanism to ensure an asymmetric outcome following cell division. [ABSTRACT FROM AUTHOR]

Two new charge-transfer compounds, [{Ru2(O2CPh-x-F)4}2(BTDA-TCNQ)]·n(solv) (x-F-PhCO2−= x-fluorobenzoate; x= o-, 4; p-, 5; BTDA-TCNQ = bis[1,2,5]thiadizolotetracyanoquinodimethane), have been prepared from reactions of paddlewheel diruthenium(II, II) complexes, [Ru2II,II(O2CPh-x-F)4] (x= o-, p-) and BTDA-TCNQ. Compounds 4and 5crystallize as two-dimensional (2-D) layered structures composed of [Ru2] units and BTDA-TCNQ in a 2 : 1 ratio. The isomer with the m-fluorobenzoate-bridged [Ru2] unit (3) exhibits a three-dimensional (3-D) structure. The oxidation states of the constituent units were evaluated from their crystal structures, and assigned to be close to the charge-polarized state represented formally as [Ru25+]–[BTDA-TCNQ−]–[Ru24+] including two types of [Ru2] units that are electronically and structurally different and a one-electron-transferred BTDA-TCNQ radical anion. The data indicate that a 1-e−transfer from one site of [Ru2] units to BTDA-TCNQ has likely occurred. The units are paramagnetic with heterospin states for [Ru2II,II] (S= 1), [Ru2II,III] (S= 3/2), and BTDA-TCNQ−(S= 1/2), which lead to magnetic ordering in the layer. In the case of 4, antiferromagnetic ordering occurs at TN= 93 K due to inter-layer antiferromagnetic interactions which involve two steps, namely canting of the ordered spins at Tc1= 87 K followed by rearrangement of the canted spin states at Tc2= 13 K. Compound 5exhibits 3-D ferromagnetic ordering at Tc= 83 K. Consequently, 4and 5behave as magnets although the origin of their spontaneous magnetization is different. The bulk magnetic properties of 4and 5are in contrast to what was observed in a similar layered compound [{Ru2(O2CCF3)4}2TCNQF4] (2; TCNQF4= tetrafluoro-7,7,8,8-tetracyanoquino-dimethane). This compound is an antiferromagnet (at H= 0) with TN= 95 K with the behavior being strongly dependent on the environment between the layers: in particular the stacking motif can either be “in-registry” with an overlap between analogous groups (for 2) or “out-of-registry” which involves a misalignment of similar groups between layers (for 4and 5). [ABSTRACT FROM AUTHOR]

Abstract  Recently, the size of solder bump interconnects have been significantly reduced with the advent of high-density packaging, and thus the evaluation of electromigration in solder bumps has become necessary. The present paper proposes a simple method to test the electromigration resistance of Pb-free solders. One of the key points of the present method is the fabrication of a simple solder sample that can produce sufficient current density to cause electromigration. Moreover, the actual local temperature of a small area subjected to electromigration in the sample was measured by a direct method. A right-angled diamond-shaped hole was introduced in a thin film of solder using a focused-ion-beam system. A direct current was supplied to the film far from the hole, perpendicular to the diagonal of the hole. In this way, the current density was concentrated near to the corner of the hole, and the value of this was obtained through a theoretical analysis. It was noted that the steady temperature in the film along a line extending from the diagonal, remained constant, although the current density decreased gradually far from the corner. Therefore, the temperature at a position near the corner, where electromigration takes place, can easily be found by measuring the temperature far from the corner. The temperature was measured directly under current flow conditions by utilizing the chemical reagents with known melting points. Finally, by measuring the ratio of hillock volume to the time for the current supply as a measure of the atomic flux divergence due to electromigration, the corresponding resistances of some Pb-free solders to electromigration were evaluated. [ABSTRACT FROM AUTHOR]

Abstract. Objective:  The objective of the present study is to investigate whether human mast cells (MC) contribute to renal damage through local activation of the renin-angiotensin system, by assessing their numbers in renal biopsy specimens from patients with IgA nephropathy (IgAN) or minimal change nephrotic syndrome (MCNS). Methods:  In patients with IgAN and MCNS, the numbers of tryptase-positive MC (MC(T)) and MC positive for both tryptase and chymase (MC(TC)) were examined histopathologically. Serum creatinine level, mean blood pressure and the severity of glomerular and tubulointerstitial lesions were also determined. Results:  MC(TC) numbers differed between IgAN patients and MCNS patients. IgAN patients had more MC(TC) than MC(T). MC were found around but not in the conglomerate of the AngiotensinII (AngII)-positive cells. In the IgAN patients with the most severe pathology, the number of AngII-positive cells was correlated with that of MC(TC) and MC(T). Conclusion:  Chymase-dependent AngII synthesis due to human MC may be involved in the inflammatory and fibrotic processes of IgAN. [ABSTRACT FROM AUTHOR]