Book review of Atlas of Anatomy by Patrick W. Tank and Thomas R. Gest:Book review of Atlas of Anatomy

Book review of Atlas of Anatomy by Patrick W. Tank and Thomas R. Gest

Double-detonation sub-Chandrasekhar supernovae: Can minimum helium shell masses detonate the core?

The explosion of sub-Chandrasekhar mass white dwarfs via the double detonation scenario is a potential explanation for type Ia supernovae. In this scenario, a surface detonation in a helium layer initiates a detonation in the underlying carbon/oxygen core leading to an explosion. For a given core mass, a lower bound has been determined on the mass of the helium shell required for dynamical burning during a helium flash, which is a necessary prerequisite for detonation. For a range of core and corresponding minimum helium shell masses, we investigate whether an assumed surface helium detonation is capable of triggering a subsequent detonation in the core even for this limiting case. We carried out hydrodynamic simulations on a co-expanding Eulerian grid in two dimensions assuming rotational symmetry. The detonations are propagated using the level-set approach and a simplified scheme for nuclear reactions that has been calibrated with a large nuclear network. The same network is used to determine detailed nucleosynthetic abundances in a post-processing step. Based on approximate detonation initiation criteria in the literature, we find that secondary core detonations are triggered for all of the simulated models, ranging in core mass from 0.810 up to 1.385 M? with corresponding shell masses from 0.126 down to 0.0035 M?. This implies that, as soon as a detonation triggers in a helium shell covering a carbon/oxygen white dwarf, a subsequent core detonation is virtually inevitable.

Gene-associated markers can assign origin in a weakly structured fish, Atlantic herring

Regulations on the exploitation of populations of commercially important fish species and the ensuing consumer interest in sustainable products have increased the need to accurately identify the population of origin of fish and fish products. Although genomics-based tools have proven highly useful, there are relatively few examples in marine fish displaying accurate origin assignment. We synthesize data for 156 single-nucleotide polymorphisms typed in 1039 herring, Clupea harengus L., spanning the Northeast Atlantic to develop a tool that allows assignment of individual herring to their regional origin. We show the method's suitability to address specific biological questions, as well as management applications. We analyse temporally replicated collections from two areas, the Skagerrak (n = 81, 84, 66) and the western Baltic (n = 52, 52). Both areas harbour heavily fished mixed-origin stocks, complicating management issues. We report novel genetic evidence that herring from the Baltic Sea contribute to catches in the North Sea, and find support that western Baltic feeding aggregations mainly constitute herring from the western Baltic with contributions from the Eastern Baltic. Our study describes a general approach and outlines a database allowing individual assignment and traceability of herring across a large part of its East Atlantic distribution.

Enhanced surface attachment of protein-type targeting ligands to poly(lactide-co-glycolide) nanoparticles using variable expression of polymeric acid functionality

The density of reactive carboxyl groups on the surface of poly(lactide-co-glycolide) (PLGA) nanoparticles (NP) was modulated using a combination of high-molecular weight (MW) encapped and low MW non-encapped PLGA. Carboxyl groups were activated using carbodiimide chemistry and conjugated to bovine serum albumin and a model polyclonal antibody. Activation of carboxyl,groups in solution-phase PLGA prior to NP formation was compared with a postformation activation of peripheral carboxyl groups on intact NP. Activation before or after NP formation did not influence conjugation efficiency to NP prepared using 100% of the low-MW PLGA. The effect of steric stabilization using poly(vinyl alcohol) reduced conjugation of a polyclonal antibody from 62 mu g/(mg NP) to 32 mu g/(mg NP), but enhanced particulate stability. Increasing the amount of a high-MW PLGA also reduced Conjugation, with the activation post-formation still superior to the preformation approach. Drug release studies showed that high proportions of high-MW PLGA in the NP produced a longer sustained release profile of a model drug (celecoxib). It can be concluded that activating intact PLGA NP is superior to activating component parts prior to NP formation. Also, high MW PLGA could be used to prolong drug release, but at the expense of conjugation efficiency on to the NP surface. (C) 2008 Wiley Periodicals, Inc. J Biomed Mater Res 87A: 873-884, 2008

Novel exon 12 mutations in the HIF2A gene associated with erythrocytosis.

Erythrocytosis can arise from deregulation of the erythropoietin (Epo) axis resulting from defects in the oxygen-sensing pathway. Epo synthesis is controlled by the hypoxia inducible factor (HIF) complex, composed of an a and a ß subunit. There are 2 main a subunits, HIF-1a and HIF-2a. Recently, a HIF-2a Gly537Trp mutation was identified in a family with erythrocytosis. This raises the possibility of HIF2A mutations being associated with other cases of erythrocytosis. We now report a subsequent analysis of HIF2A in a cohort of 75 erythrocytosis patients and identify 4 additional patients with novel heterozygous Met535Val and Gly537Arg mutations. All patients presented at a young age with elevated serum Epo. Mutations at Gly-537 account for 4 of 5 HIF2A mutations associated with erythrocytosis. These findings support the importance of HIF-2a in human Epo regulation and warrant investigation of HIF2A in patients with unexplained erythrocytosis.

Strategies toward the design of energetic ionic liquids: nitro- and nitrile-substituted N,N '-dialkylimidazolium salts

Twelve novel 1,3-dialkylimidazolium salts containing strongly electron-withdrawing nitro-and cyano-functionalities directly appended to the cationic heterocyclic rings have been synthesized; the influences of the substituents on both formation and thermal properties of the resultant ionic liquids have been determined by DSC, TGA, and single crystal X-ray diffraction, showing that an electron-withdrawing nitro-substituent can be successfully appended and has a similar influence on the melting behaviour as that of corresponding methyl group substitution. Synthesis of di-, or trinitro-substituted 1,3-dialkylimidazolium cations was unsuccessful due to the resistance of dinitro-substituted imidazoles to undergo either N-alkylation or protonation, while 1-alkyl- 4,5-dicyanoimidazoles were successfully alkylated to obtain 1,3-dialkyl-4,5-dicyanoimidazolium salts. Five crystal structures ( one of each cation type) show that, in the solid state, the NO2-group has little significant effect, beyond the steric contribution, on the crystal packing.

Efficient, halide free synthesis of new, low cost ionic liquids: 1,3-dialkylimidazolium salts containing methyl- and ethyl-sulfate anions

New low-cost ionic liquids containing methyl- and ethyl-sulfate anions can be easily and efficiently prepared under ambient conditions by the reaction of 1-alkylimidazoles with dimethyl sulfate and diethyl sulfate. The preparation and characterization of a series of 1,3-dialkylimidazolium alkyl sulfate and 1,2,3-trialkylimidazolium alkyl sulfate salts are reported. 1,3-Dialkylimidazolium salts containing at least one non-methyl N-alkyl substituent are liquids at, or below room, temperature. Three salts were crystalline at room temperature, the single crystal X-ray structure of 1,3-dimethylimidazolium methyl sulfate was determined and shows the formation of discrete ribbons comprising of two anion-cation hydrogen-bonded chains linked via intra-chain hydrogen-bonding, but little, or no inter-ribbon hydrogen-bonding. The salts are stable, water soluble, inherently 'chloride-free', display an electrochemical window of greater than 4 V, and can be used as alternatives to the corresponding halide salts in metathesis reactions to prepare other ionic liquids including 1-butyl-3-methylimidazolium hexafluorophosphate.

Resting energy expenditure in non-ventilated, non-sedated patients recovering from serious traumatic brain injury: Comparison of prediction equations with indirect calorimetry values

Background & aims: Little is known about energy requirements in brain injured (TBI) patients, despite evidence suggesting adequate nutritional support can improve clinical outcomes. The study aim was to compare predicted energy requirements with measured resting energy expenditure (REE) values, in patients recovering from TBI.

Methods: Indirect calorimetry (IC) was used to measure REE in 45 patients with TBI. Predicted energy requirements were determined using FAO/WHO/UNU and Harris–Benedict (HB) equations. Bland– Altman and regression analysis were used for analysis.

Results: One-hundred and sixty-seven successful measurements were recorded in patients with TBI. At an individual level, both equations predicted REE poorly. The mean of the differences of standardised areas of measured REE and FAO/WHO/UNU was near zero (9 kcal) but the variation in both directions was substantial (range 591 to þ573 kcal). Similarly, the differences of areas of measured REE and HB demonstrated a mean of 1.9 kcal and range 568 to þ571 kcal. Glasgow coma score, patient status, weight and body temperature were signi?cant predictors of measured REE (p < 0.001; R²⁼ 0.47).

Conclusions: Clinical equations are poor predictors of measured REE in patients with TBI. The variability in REE is substantial. Clinicians should be aware of the limitations of prediction equations when estimating energy requirements in TBI patients.

Structural basis for the platelet-collagen interaction - The smallest motif within collagen that recognizes and activates platelet glycoprotein VI contains two glycine-proline-hydroxyproline triplets

Collagen-related peptide is a selective agonist for the platelet collagen receptor Glycoprotein VI. The triple helical peptide contains ten GPO triplets/strand (single letter amino acid nomenclature, where O is hydroxyproline) and so over-represents GPO compared with native collagen sequence. To investigate the ability of Glycoprotein VI to recognize GPO triplets in a setting more representative of the collagens, we synthesized a set of triple helical peptides containing fewer GPO triplets, varying their number and spacing within an inert (GPP)(n) backbone. The adhesion of recombinant human Glycoprotein VI ectodomain, like that of human platelets, to these peptides increased with their GPO content, and platelet adhesion was abolished by the specific anti-Glycoprotein VI-blocking antibody, 10B12. Platelet aggregation and protein tyrosine phosphorylation were induced only by cross-linked peptides and only those that contained two or more GPO triplets. Such peptides were less potent than cross-linked collagen-related peptide. Our data suggest that both the sequences GPOGPO and GPO center dot center dot center dot center dot center dot center dot center dot center dot center dot GPO represent functional Glycoprotein VI recognition motifs within collagen. Furthermore, we propose that the (GPO)(4) motif can support simultaneous binding of two glycoprotein VI molecules, in either a parallel or anti-parallel stacking arrangement, which could play an important role in activation of signaling.

Thermal conductivity measurement of liquids in a microfluidic device

A new microfluidic-based approach to measuring liquid thermal conductivity is developed to address the requirement in many practical applications for measurements using small (microlitre) sample size and integration into a compact device. The approach also gives the possibility of high-throughput testing. A resistance heater and temperature sensor are incorporated into a glass microfluidic chip to allow transmission and detection of a planar thermal wave crossing a thin layer of the sample. The device is designed so that heat transfer is locally one-dimensional during a short initial time period. This allows the detected temperature transient to be separated into two distinct components: a short-time, purely one-dimensional part from which sample thermal conductivity can be determined and a remaining long-time part containing the effects of three-dimensionality and of the finite size of surrounding thermal reservoirs. Identification of the one-dimensional component yields a steady temperature difference from which sample thermal conductivity can be determined. Calibration is required to give correct representation of changing heater resistance, system layer thicknesses and solid material thermal conductivities with temperature. In this preliminary study, methanol/water mixtures are measured at atmospheric pressure over the temperature range 30-50A degrees C. The results show that the device has produced a measurement accuracy of within 2.5% over the range of thermal conductivity and temperature of the tests. A relation between measurement uncertainty and the geometric and thermal properties of the system is derived and this is used to identify ways that error could be further reduced.

SUPERNOVA 2009kf: AN ULTRAVIOLET BRIGHT TYPE IIP SUPERNOVA DISCOVERED WITH PAN-STARRS 1 AND GALEX

We present photometric and spectroscopic observations of a luminous Type IIP Supernova (SN) 2009kf discovered by the Pan-STARRS 1 (PS1) survey and also detected by the Galaxy Evolution Explorer. The SN shows a plateau in its optical and bolometric light curves, lasting approximately 70 days in the rest frame, with an absolute magnitude of M-V = - 18.4 mag. The P-Cygni profiles of hydrogen indicate expansion velocities of 9000 km s(-1) at 61 days after discovery which is extremely high for a Type IIP SN. SN 2009kf is also remarkably bright in the near-ultraviolet (NUV) and shows a slow evolution 10-20 days after optical discovery. The NUV and optical luminosity at these epochs can be modeled with a blackbody with a hot effective temperature (T similar to 16,000 K) and a large radius (R similar to 1 x 10(15) cm). The bright bolometric and NUV luminosity, the light curve peak and plateau duration, the high velocities, and temperatures suggest that 2009kf is a Type IIP SN powered by a larger than normal explosion energy. Recently discovered high-z SNe (0.7

A nearly real-time high temperature laser-plasma diagnostic using photonuclear reactions in tantalum

A method of measuring the temperature of the fast electrons produced in ultraintense laser-plasma interactions is described by inducing photonuclear reactions, in particular (gamma,n) and (gamma,3n) reactions in tantalum. Analysis of the gamma rays emitted by the daughter nuclei of these reactions using a germanium counter enables a relatively straightforward near real-time temperature measurement to be made. This is especially important for high temperature plasmas where alternative diagnostic techniques are usually difficult and time consuming. This technique can be used while other experiments are being conducted. (C) 2002 American Institute of Physics.

Laser generation of proton beams for the production of short-lived positron emitting radioisotopes

Protons of energies up to 37 MeV have been generated when ultra-intense lasers (up to 10(20) W cm(-2)) interact with hydrogen containing solid targets. These protons can be used to induce nuclear reactions in secondary targets to produce P-emitting nuclei of relevance to the nuclear medicine community, namely C-11 and N-13 via (p, n) and (p, alpha) reactions. Activities of the order of 200 kBq have been measured from a single laser pulse interacting with a thin solid target. The possibility of using ultra-intense lasers to produce commercial amounts of short-lived positron emitting sources for positron emission tomography (PET) is discussed. (C) 2001 Elsevier Science B.V. All rights reserved.

Lipoproteins in the DCCT/EDIC cohort:associations with diabetic nephropathy

Lipoproteins may contribute to diabetic nephropathy. Nuclear magnetic resonance (NMR) can quantify subclasses and mean particle size of very low density lipoprotein (VLDL), low density lipoprotein (LDL), and high density lipoprotein (HDL), and LDL particle concentration. The relationship between detailed lipoprotein analyses and diabetic nephropathy is of interest.

Coprolites from the Cretaceous Bearpaw Formation of Saskatchewan

Coprolites from the Beechy Member of the Cretaceous Bearpaw Formation, southern Saskatchewan, presumably deposited by one or more species of mosasaur or large fish/shark, were recovered and analyzed using SEM/EDS. The data reveal the presence of pseudomorphous coccoid bacteria, potential filamentous bacteria, bacterial endospores and filamentous fungi. No recorded fossil plant or bone material could be identified, either within the highly compressed coprolitic mat-flattened full coprolite bolus - of recovered marine sediment encased in a mixed mat of hematite-apatite primary minerals heavily coated with Ca-smectite and nontronite, or the full coprolite bolus. The presence of fossil bacteria with morphological characteristics similar to those of endospores in other environments suggests that only robust microbial forms such as these survive diagenesis, partly with some carbon still intact, the remainder replaced with silica and iron. The data support the view that coprolites can serve as a useful source of information on the ancient microbial world. © 2012 Elsevier Ltd.