The effects of depressed pH on spermatogenesis in flagfish Jordanella floridae

Mature male flagfish Jordanella floridae were continuously exposed to lake water with depressed pH levels of 6.0, 5.5, 5.0 and 4.5 during a 20 day period at 25°C. Quantitative histological analysis based upon the final stage of spermatogenesis prior to sperm formation indicated that the production of mature sperm was reduced at all pH values tested by 24.03, 27.03, 37.28 and 35.29% respectively when compared with the control at pH 6.7. Total volume of reproductive tissue relative to somatic tissue within the testes showed similar declines of 24.64, 25.39, 24.81 and 38.50% respectively compared to the control. The general decline in spermatogenesis was confirmed morphologically by increased occurrence of tubules devoid of sperm and was particularly evident at pH 4.5. Comparison of the present results with data from female ovaries of the same experiment suggests a higher sensitivity of developing eggs to declining pH when compared with developing sperm.     

Correlation-based method for comparing and reconstructing nearly identical two-dimensional structures

A method for comparing and reconstructing two nearly identical planar objects that are composed of the same number of identical apertures is presented. These structures differ only in the location of one of the apertures. The method is based on a subtraction algorithm, which involves the cross-correlation and autocorrelation functions of the compared structures. Simulated results illustrate the feasibility of the method.     

Single-Cycle Bit Permutations with MOMR Execution

Secure computing paradigms impose new architectural challenges for general-purpose processors. Cryptographic processing is needed for secure communications, storage, and computations. We identify two categories of operations in symmetric-key and public-key cryptographic algorithms that are not common in previous general-purpose workloads： advanced bit operations within a word and multi-word operations. We define MOMR （Multiple Operands Multiple Results） execution or datarich execution as a unified solution to both challenges. It allows arbitrary n-bit permutations to be achieved in one or two cycles, rather than O（n） cycles as in existing RISC processors. It also enables significant acceleration of multiword multiplications needed by public-key ciphers. We propose two implementations of MOMR： one employs only hardware changes while the other uses Instruction Set Architecture （ISA） support. We show that MOMR execution leverages available resources in typical multi-issue processors with minimal additional cost. Multi-issue processors enhanced with MOMR units provide additional speedup over standard multi-issue processors with the same datapath. MOMR is a general architectural solution for word-oriented processor architectures to incorporate datarich operations.     

CATHARE 2 V2.5_2: A single version for various applications

This paper presents the new capabilities of CATHARE 2 as a multi-purpose multi-reactor concept system code. The CATHARE 2 code was originally devoted to best estimate calculations of thermal-hydraulic transients in Water-Cooled Reactors such as PWR, VVER or BWR. Recently, in the framework of the Generation IV International Forum, CEA launched several feasibility studies of future advanced reactor concepts including Gas-Cooled Reactors, Sodium-Cooled Fast-Breeder Reactors, Supercritical Water-Cooled Reactors. The 2-fluid model with non-condensable gases transport equations was first easily extended to Gas-Cooled Reactor applications with very few modifications. At the same time CEA seized opportunity to use CATHARE 2 to perform studies for non-nuclear industrial applications such as cryogenic rocket engines. New capabilities were implemented allowing passage from supercritical pressure to subcritical conditions and these features were then easily applied to Supercritical Water-Cooled Reactors. New developments were also necessary to extend the code to Sodium-Cooled Reactors. CATHARE 2 can now describe several circuits with various fluids either in single-phase gas or liquid, or in two-fluid conditions possibly with noncondensable gases, which allows simulating any kind of reactor concept and any kind of accidental transient.The development method for the extension to new fluids is presented with an overview of the most striking functional and modelling features that have been implemented in the new CATHARE 2 V2.5_2 version to be released mid-2009 for industrial applications.     

Nominal energy optimisation method of constrained battery packs through the iteration of the series‐parallel topology

The design of a battery pack commonly deals with high performance goals and challenging constraints in terms of cost, volume or weight. One of the most crucial variables to maximise is the nominal energy, which depends on the number of discrete battery cells that can be allocated and their individual technical specifications. This work proposes a systematic method to optimise the nominal energy of a constrained battery pack from the perspective of the series‐parallel topology. A mathematical and graphical characterisation is presented on how the main battery's variables are related to a topology bounded to discretisation procedures. It was theoretically found that the effects of rounding the values of the topology may lead to a considerable loss of potential nominal energy, a risk that increases linearly with the number of series. The behaviour of the battery is assessed under nominal conditions and under the event of a cell failure. The theoretical analysis suggests that the detrimental effects due to an open‐circuit increase as the number of series increases, while it is the opposite in the case of a shorted cell. The method is satisfactorily implemented in the development of two different battery packs for solar competition cars with limiting regulations. The candidate topologies outperformed the nominal energy of topologies defined without the method in up to 5%. It was also found that selecting an energy‐maximising topology is not always the most convenient choice, because other variables may be of interest and are dependent on the topology as well. The method is of great use to guide the topology definition process in early theoretical stages, which is usually a compromise between allocating as much cells as possible within constraints, and approaching other performance goals such as a given nominal voltage or capacity. Copyright © 2017 John Wiley & Sons, Ltd.     

Evidence of enantioselective degradation of alpha-hexachlorocyclohexane in groundwater

In the fall of 2000, 34 groundwater samples were collected from beneath an active pesticide reformulating and packaging facility in coastal northeastern Florida to measure the enantiomer fractions (EFs) of alpha-hexachlorocyclohexane (alpha-HCH) as an indicator of biodegradation of this chlorinated pesticide in groundwater. Concentrations of alpha-HCH as high as 500 microg/L were observed beneath the historical source area and decreased with distance downgradient. Seventy-eight percent of the EF values were greater than 0.504 and ranged up to 0.890, indicating that the (-)-alpha-HCH enantiomer is preferentially degraded relative to the (+)-alpha-HCH enantiomer at this site. Samples taken from the groundwater that flows north from the historical disposal facility to a local discharge point at a creek did not indicate enantioselective degradation (EF values ranged from 0.495 to 0.512). The acidity (pH 3.7-4.6) and short flow path to the creek for this lobe of the groundwater plume likely preclude biodegradation of alpha-HCH. In contrast, the neutral lobe of the groundwater plume, which flows eastward from the historical source area, demonstrated enantioselective degradation (EF values ranged from 0.500 to 0.890 and increased with distance from the source area). Groundwater conditions beneath this portion of the site are conducive to biodegradation of HCH owing to anaerobic reducing conditions and lengthy travel times, and the chiral signatures for alpha-HCH provide evidence that biological degradation is occurring beneath this portion of the site.     

The invisible benefits of exercise.

Objective: To examine whether—and why—people underestimate how much they enjoy exercise. Design: Across four studies, 279 adults predicted how much they would enjoy exercising, or reported their actual feelings after exercising. Main Outcome Measures: Main outcome measures were predicted and actual enjoyment ratings of exercise routines, as well as intention to exercise. Results: Participants significantly underestimated how much they would enjoy exercising; this affective forecasting bias emerged consistently for group and individual exercise, and moderate and challenging workouts spanning a wide range of forms, from yoga and Pilates to aerobic exercise and weight training (Studies 1 and 2). We argue that this bias stems largely from forecasting myopia, whereby people place disproportionate weight on the beginning of a workout, which is typically unpleasant. We demonstrate that forecasting myopia can be harnessed (Study 3) or overcome (Study 4), thereby increasing expected enjoyment of exercise. Finally, Study 4 provides evidence for a mediational model, in which improving people's expected enjoyment of exercise leads to increased intention to exercise. Conclusion: People underestimate how much they enjoy exercise because of a myopic focus on the unpleasant beginning of exercise, but this tendency can be harnessed or overcome, potentially increasing intention to exercise. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

1.5-GHz voltage controlled oscillator with 3% tuning bandwidth using a two-pole DSBAR filter

First results on a novel voltage controlled oscillator (VCO) in the lower gigahertz range, featuring excellent phase noise and high power efficiency are presented. The heart of the VCO is a recently reported novel miniature two-pole decoupled stacked bulk acoustic resonator (DSBAR) filter. With its single 180° phase transition over the 1 dB bandwidth, linear phase, and maximum 1 dB insertion loss, it provides stable single-mode operation over 45 MHz (≈3%) of tuning bandwidth and has negligible heat dissipation when operated at incident power levels of 100 mW or greater. The 1.55-GHz laboratory VCO prototypes operate at 5 V supply voltage, 50 mA supply current, 15 dBm of output power, and >13% efficiency, demonstrating -84 and < -180 dBc/Hz phase noise suppression at 1 kHz carrier offset and in the thermal noise region, respectively. VCOs with cascaded DSBAR filters for further phase noise reduction are also demonstrated.