Surveillance study of a number of synthetic and natural growth promoters in bovine muscle samples using liquid chromatography-tandem mass spectrometry

A simple, new method permitting the simultaneous determination and confirmation of trace residues of 24 different growth promoters and metabolites using liquid chromatography-mass spectrometry was developed and validated. The compounds were extracted from bovine tissue using acetonitrile; sodium sulphate was also added at this stage to aid with purification. The resulting mixture was then evaporated to approximately 1 ml and subsequently centrifuged at high speed and an aliquot injected onto the LC-MS/MS system. The calculated CCα values ranged between 0.11 and 0.46 μg kg(-1); calculated CCβ were in the range 0.19-0.79 μg kg(-1). Accuracy, measurement of uncertainty, repeatability and linearity were also determined for each analyte. The analytical method was applied to a number of bovine tissue samples imported into Ireland from third countries. Levels of progesterone were found in a number of samples at concentrations ranging between 0.28 and 30.30 μg kg(-1). Levels of alpha- and beta-testosterone were also found in a number of samples at concentrations ranging between 0.22 and 8.63 μg kg(-1) and between 0.16 and 2.08 μg kg(-1) respectively.     

Long-period grating inscription in hydrogen-free SMF-28 fiber by high-repetition-rate femtosecond UV pulses

Using femtosecond UV (258 nm) pulses, generated at high-repetition-rate (50 kHz), we managed to record high-quality long-period gratings in a number of fibers, including a standard telecommunication one, SMF-28. Along with the main grating, connected to the refractive index change in the fiber core, at the relatively high intensity of the inscribing UV radiation, I ～ 1.5 TW/cm², we recorded the formation of an additional long-period grating, based on the refractive index change induced in the fiber cladding. We have compared the temperature sensitivity and the thermal stability of both gratings.     

Orientation‐Controlled Selective‐Area Epitaxy of III–V Nanowires on (001) Silicon for Silicon Photonics

Monolithic integration of III–V nanowires on silicon platforms has been regarded as a promising building block for many on‐chip optoelectronic, nanophotonic, and electronic applications. Although great advances have been made from fundamental material engineering to realizing functional devices, one of the remaining challenges for on‐chip applications is that the growth direction of nanowires on Si(001) substrates is difficult to control. Here, catalyst‐free selective‐area epitaxy of nanowires on (001)‐oriented silicon‐on‐insulator (SOI) substrates with the nanowires aligned to desired directions is proposed and demonstrated. This is enabled by exposing {111} planes on (001) substrates using wet chemical etching, followed by growing nanowires on the exposed planes. The formation of nanowire array‐based bottom‐up photonic crystal cavities on SOI(001) and their coupling to silicon waveguides and grating couplers, which support the feasibility for on‐chip photonic applications are demonstrated. The proposed method of integrating position‐ and orientation‐controllable nanowires on Si(001) provides a new degree of freedom in combining functional and ultracompact III–V devices with mature silicon platforms.     

Review of Clinician's guide to PTSD: A cognitive-behavioural approach.

Reviews the book, Clinician's guide to PTSD: A cognitive-behavioural approach by Steven Taylor (2007). In this book, Steven Taylor takes on the lofty challenge of summarizing the research on Post-traumatic Stress Disorder (PTSD) as it relates to assessment and treatment. The book is divided into two sections: conceptual and empirical foundations, and treatment methods and protocols. As the title suggests, the book is based on a cognitive-behavioural model and as such is directed at individuals who have some knowledge of and experience with using this treatment modality. However, practitioners of all theoretical orientations will benefit from reading this book. Clinician's guide to PTSD is an excellent resource with respect to reviewing the research on predisposing factors, risk factors and, assessment tools. The chapter on case formulation is excellent, and the section on the application of cognitive behaviour therapy to PTSD is very useful and pragmatic. Furthermore, this is a very well-written book and is thankfully devoid of jargon. If you treat people who have been traumatized, then this book is essential reading. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The isothermal decomposition of austenite in hot-rolled microalloyed steels

The isothermal decomposition of austenite has been examined in a set of 0.1 C, 1.4 Mn steels containing small amounts of Ti, V, or Nb. The volume fraction of ferrite was measured as a function of transformation temperature and holding time, after hot rolling. Precipitation of carbonitrides, in both the austenite and the ferrite, was examined by electron microscopy of extraction replicas. The decomposition is slowest in the Nb-alloyed steel, in which the start of transformation is delayed and ferrite growth rates are much lower than in the other steels. In the V-alloyed steels, ferrite growth rates are lower than in the plain carbon or Ti alloyed steels. These results are discussed in terms of the effects of carbonitride precipitation in the austenite during high temperature deformation and in the ferrite during transformation. The roles of V and Nb in solution are also considered.     

Binocular correlates of the direction of motion in depth

Two binocular cues to the direction of an object's motion in depth are the ratio (phi R/phi L) between the velocities of the object's retinal images in the right and left eyes and the ratio (phi/gamma) between the velocity of the binocularly-fused image of the object and the rate of change of disparity. We report that the apparent direction of motion in depth of a monocularly-camouflaged target can be varied by altering the ratio phi/gamma. Because no monocular motion signal is available in this case, we conclude that the ratio phi/gamma is a sufficient cue to the direction of motion in depth. This is not to deny that the phi R/phi L cue might be used in the everyday visual situation where monocular velocities phi R and phi L are available to the brain.     

A fail safe cryogenic liquid level controller

Herein described is a device which is capable of detecting the presence of liquids, especially in the cryogic region, and whose sensor will not overheat in a vacuum. The circuit architecture is such that the default state for any predictable failure is the closure of the filling value.     

Interaction of CArG elements and a GC-rich repressor element in transcriptional regulation of the smooth muscle myosin heavy chain gene in vascular smooth muscle cells

We have previously shown that maximal expression of the rat smooth muscle myosin heavy chain (SM-MHC) gene in cultured rat aortic smooth muscle cells (SMCs) required the presence of a highly conserved domain (nucleotides -1321 and -1095) that contained two positive-acting serum response factor (SRF) binding elements (CArG boxes 1 and 2) and a negative-acting GC-rich element that was recognized by Sp1 (Madsen, C. S., Hershey, J. C., Hautmann, M. B., White, S. L., and Owens, G. K. (1997) J. Biol. Chem. 272, 6332-6340). In this study, to better understand the functional role of these three cis elements, we created a series of SM-MHC reporter-gene constructs in which each element was mutated either alone or in combination with each other and tested them for activity in transient transfection assays using primary cultured rat aortic SMCs. Results demonstrated that the most proximal SRF binding element (CArG-box1) was active in the absence of CArG-box2, but only upon removal of the GC-rich repressor. In contrast, regardless of sequence context, CArG-box2 was active only when CArG-box1 was present. We further demonstrated using electrophoretic mobility shift assays that Sp1 binding to the GC-rich repressor element did not prevent SRF binding to the adjacent CArG-box2. Thus, unlike other proteins reported to inhibit SRF activity, the repressor activity associated with the GC-rich element does not appear to function through direct inhibition of SRF binding. As a first step toward understanding the importance of these elements in vivo, we performed in vivo footprinting on the intact rat aorta. We demonstrated that both CArG boxes and the GC-rich element were bound by protein within the animal. Additionally, using the rat carotid injury model we showed that Sp1 protein was significantly increased in SMCs located within the myointimal lesion, suggesting that increased expression of this putative repressor factor may contribute to the decreased SM MHC expression within SMCs found in myointimal lesions.