Heritability as an indicator of genetical variation in fecundity

Heritability is well known to be a poor indicator of genetical variation in fitness. We show here that it is also an inadequate measure of genetical variation in fecundity.     

The influence of elastic strain energy on the formation of coherent hexagonal phases

The elastic strain energy function,Y (n), of coherent hexagonal phases has been derived for arbitrary directions,n, in a parent phase with arbitrary crystal structure. These calculations indicate that in all casesY (n) exhibits transverse isotropy about thec axis. As a result,Y (n) has a pronounced effect on the morphology of the precipitating structures. In the case of hexagonal inclusions, three possible optimum shapes in reciprocal space are identified: 1) a rod parallel to thec axis, 2) a plate perpendicular to thec axis, and 3) a hollow conical shape with the axis of revolution parallel toc. The precise precipitate shape can be predicted by identifying the directionn _o which minimizes the strain energy function,Y (n). Evaluation ofY (n) for η and ή MgZn2 precipitates in the ternary Al-Mg-Zn system correctly predicts the orientation and morphology of the particles. This method has also been extended to explore the morphology of the microstructure of hexagonal spinodal alloys. It is shown that the gradient energy term is generally anisotropic, and that together with the strain energy function,Y(n), has a strong influence on composition fluctuations. It is predicted that a one-dimensional periodic compositional variation along the [001] direction should be observed whenY [001] is a global minimum. In all other cases, the microstructure is complex and lacks periodicity.     

A 400-MHz S/390 microprocessor

A microprocessor implementing IBM S/390 architecture operates in a 10+2 way system at frequencies up to 411 MHz (2.43 ns). The chip is fabricated in a 0.2-μm L_eff CMOS technology with five layers of metal and tungsten local interconnect. The chip size is 17.35 mm×17.30 mm with about 7.8 million transistors. The power supply is 2.5 V and measured power dissipation at 300 MHz is 37 W. The microprocessor features two instruction units (IUs), two fixed point units (FXUs), two floating point units (FPUs), a buffer control element (BCE) with a unified 64-KB L1 cache, and a register unit (RU). The microprocessor dispatches one instruction per cycle. The dual-instruction, fixed, and floating point units are used to check each other to increase reliability and not for improved performance. A phase-locked-loop (PLL) provides a processor clock that runs at 2× the system bus frequency. High-frequency operation was achieved through careful static circuit design and timing optimization, along with limited use of dynamic circuits for highly critical functions, and several different clocking/latching strategies for cycle time reduction. Timing-driven synthesis and placement of the control logic provided the maximum flexibility with minimum turnaround time. Extensive use of self-resetting CMOS (SRCMOS) circuits in the on-chip L1 cache provides a 2.0-ns access time and up to 500 MHz operation     

CfDNA Measurement as a Diagnostic Tool for the Detection of Brain Somatic Mutations in Refractory Epilepsy

Epilepsy is a neurological disorder that affects more than 50 million people. Its etiology is unknown in approximately 60% of cases, although the existence of a genetic factor is estimated in about 75% of these individuals. Hundreds of genes involved in epilepsy are known, and their number is increasing progressively, especially with next-generation sequencing techniques. However, there are still many cases in which the results of these molecular studies do not fully explain the phenotype of the patients. Somatic mutations specific to brain tissue could contribute to the phenotypic spectrum of epilepsy. Undetectable in the genomic DNA of blood cells, these alterations can be identified in cell-free DNA (cfDNA). We aim to review the current literature regarding the detection of somatic variants in cfDNA to diagnose refractory epilepsy, highlighting novel research directions and suggesting further studies.     

Microscopic-damage-based criterion for fatigue failure prediction

A computer-aided X-ray rocking curve analyser was developed to monitor the accrued microstructural damage occurring during low cycle fatigue of an aluminium alloy. These results indicated a linear relationship between the X-ray rocking curve half-width and the fraction of life. The resultant damage-assessment curve provided a nondestructive means of estimating the time to failure in a sample with unknown prior loading history. This failure criterion was found to be independent of the strain amplitude and was equally applicable to either high cycle or low cycle fatigue.     

Reliability of scores on the Stroke Rehabilitation Assessment of Movement (STREAM) measure

BACKGROUND AND PURPOSE: The Stroke Rehabilitation Assessment of Movement (STREAM) is a new clinical measurement tool for evaluating the recovery of voluntary movement and basic mobility following stroke. This article presents the results of 3 substudies examining the reliability (interrater and intrarater) and internal consistency of STREAM scores. SUBJECTS AND METHODS: A "direct-observation reliability study" was conducted on 20 patients who had strokes and were in a rehabilitation setting. Pairs of raters from a group of 6 participating therapists provided data to judge interrater agreement. A "videotaped assessments reliability study" was done to assess intrarater and interrater agreement on the scoring of videotaped performances using the STREAM measure and involved 4 videotaped assessments that were viewed and rated on 2 occasions by 20 physical therapists. The internal consistency of the STREAM scores was evaluated for 26 patients who had strokes and who demonstrated the full range of motor ability. RESULTS: The reliability of the STREAM scores was demonstrated by generalizability correlation coefficients of .99 for total scores and of .96 to .99 for subscale scores. The internal consistency of the STREAM scores was demonstrated by Cronbach alphas of greater than .98 on the subscales and overall. CONCLUSION AND DISCUSSION: These high levels of reliability support the use of the STREAM instrument for the measurement of motor recovery following stroke. Further work on the validity and responsiveness of the STREAM measure is in progress.     

Jamaican bioethanol: an environmental and economic life cycle assessment

Clean Technologies and Environmental Policy - E10 is a blend of 10% bioethanol and 90% gasoline that can be used in the engines of most cars without causing damage. Currently for the E10 blend,...     

Use of changes in triacylglycerols during ripening of cheeses with high lipolysis levels for detection of milk fat authenticity

The triacylglycerol (TAG) compositions by carbon number during ripening of two Protected Designation of Origin (PDO) cheeses were analysed using short capillary column gas chromatography. Lipolysis levels were high in the Cabrales (blue cheese produced from cows’ milk or from blends of cows’ with goats’ milk) and Majorero goats’ milk cheeses at the end of ripening, with free fatty acid (FFA) levels of around 24 000 ppm and significant changes in the TAG composition. The level of lipolysis in an industrial blue cheese made from ewes’ milk was low, with an FFA value of around 6000 ppm and no significant changes in the TAG composition during ripening. The TAG values recorded for each cheese sample were substituted into the multiple regression equations that have been proposed for use in detecting foreign fats in milk fat. The values thus obtained were within the established ranges in early ripening. In the cheeses with high lipolysis levels during ripening, some of the values obtained fell outside the established ranges. These equations can be potentially useful for detecting foreign fats in these cheeses, when employed early in the ripening period. Furthermore, it is important to take into account that before coming to a conclusion about cheese authenticity, several individual samples should be analysed.     

Exploring the interoperability of remote GPGPU virtualization using rCUDA and directive-based programming models

Directive-based programming models, such as OpenMP, OpenACC, and OmpSs, enable users to accelerate applications by using coprocessors with little effort. These devices offer significant computing power, but their use can introduce two problems: an increase in the total cost of ownership and their underutilization because not all codes match their architecture. Remote accelerator virtualization frameworks address those problems. In particular, rCUDA provides transparent access to any graphic processor unit installed in a cluster, reducing the number of accelerators and increasing their utilization ratio. Joining these two technologies, directive-based programming models and rCUDA, is thus highly appealing. In this work, we study the integration of OmpSs and OpenACC with rCUDA, describing and analyzing several applications over three different hardware configurations that include two InfiniBand interconnections and three NVIDIA accelerators. Our evaluation reveals favorable performance results, showing low overhead and similar scaling factors when using remote accelerators instead of local devices.