Performance projections and design optimization of planar double gate SOI MOSFETs for logic technology applications

In this paper, by investigating the influence of source/drain extension region engineering (also known as gate-source/drain underlap) in nanoscale planar double gate (DG) SOI MOSFETs, we offer new insights into the design of future nanoscale gate-underlap DG devices to achieve ITRS projections for high performance (HP), low standby power (LSTP) and low operating power (LOP) logic technologies. The impact of high-kappa gate dielectric, silicon film thickness, together with parameters associated with the lateral source/drain doping profile, is investigated in detail. The results show that spacer width along with lateral straggle can not only effectively control short-channel effects, thus presenting low off-current in a gate underlap device, but can also be optimized to achieve lower intrinsic delay and higher on-off current ratio (I-on/I-off). Based on the investigation of on-current (I-on), off-current (I-off), I-on/I-off, intrinsic delay (tau), energy delay product and static power dissipation, we present design guidelines to select key device parameters to achieve ITRS projections. Using nominal gate lengths for different technologies, as recommended from ITRS specification, optimally designed gate-underlap DG MOSFETs with a spacer-to-straggle (s/sigma) ratio of 2.3 for HP/LOP and 3.2 for LSTP logic technologies will meet ITRS projection. However, a relatively narrow range of lateral straggle lying between 7 to 8 nm is recommended. A sensitivity analysis of intrinsic delay, on-current and off-current to important parameters allows a comparative analysis of the various design options and shows that gate workfunction appears to be the most crucial parameter in the design of DG devices for all three technologies. The impact of back gate misalignment on I-on, I-off and tau is also investigated for optimized underlap devices.

Herpes simplex virus type 1 and Alzheimer's disease: the autophagy connection.

The causes of Alzheimer's disease (AD) and of the characteristic pathological features—amyloid plaques and neurofibrillary tangles—of AD brain are unknown, despite the enormous resources provided over the years for their investigation. Indeed, the only generally accepted risk factors are age, Down syndrome, carriage of the type 4 allele of the apolipoprotein E gene (APOE-e 4), and possibly brain injury. Following the authors' previous studies implicating herpes simplex virus type 1 (HSV1) in brain of APOE-e 4 carriers as a major cause of AD, the authors propose here, on the basis of their and others' recent studies, that not only does HSV1 generate the main components of amyloid plaques and neurofibrillary tangles (NFTs)—ß -amyloid (Aß) and abnormally phosphorylated tau but also, by disrupting autophagy, it prevents degradation of these aberrant proteins, leading to their accumulation and deposition, and eventually to AD.

Emission lines of Fe X in active region spectra obtained with the Solar Extreme-ultraviolet Research Telescope and Spectrograph

Fully relativistic calculations of radiative rates and electron impact excitation cross-sections for Fe X are used to derive theoretical emission-line ratios involving transitions in the 174-366 angstrom wavelength range. A comparison of these with solar active region observations obtained during the 1989 and 1995 flights of the Solar Extreme-ultraviolet Research Telescope and Spectrograph (SERTS) reveals generally very good agreement between theory and experiment. Several Fe X emission features are detected for the first time in SERTS spectra, while the 3s(2)3p(5) P-2(3/2)-3s(2)3p(4)(S-1)3d D-2(3/2) transition at 195.32 angstrom is identified for the first time (to our knowledge) in an astronomical source. The most useful Fe X electron density (N-e) diagnostic line ratios are assessed to be 175.27/174.53 and 175.27/177.24, which both involve lines close in wavelength and free from blends, vary by factors of 13 between N-e = 10(8) and 10(11) cm(-3), and yet show little temperature sensitivity. Should these lines not be available, then the 257.25/345.74 ratio may be employed to determine N-e, although this requires an accurate evaluation of the instrument intensity calibration over a relatively large wavelength range. However, if the weak 324.73 angstrom line of Fe X is reliably detected, the use of 324.73/345.74 or 257.25/324.73 is recommended over 257.25/345.74. Electron densities deduced from 175.27/174.53 and 175.27/177.24 for the stars Procyon and alpha Cen, using observations from the Extreme-Ultraviolet Explorer (EUVE) satellite, are found to be consistent and in agreement with the values of N-e determined from other diagnostic ratios in the EUVE spectra. A comparison of several theoretical extreme-ultraviolet Fe X line ratios with experimental values for a theta-pinch, for which the plasma parameters have been independently determined, reveals reasonable agreement between theory and observation, providing some independent support for the accuracy of the adopted atomic data.

Using time-to-contact information to assess potential collision modulates both visual and temporal prediction networks

Accurate estimates of the time-to-contact (TTC) of approaching objects are crucial for survival. We used an ecologically valid driving simulation to compare and contrast the neural substrates of egocentric (head-on approach) and allocentric (lateral approach) TTC tasks in a fully factorial, event-related fMRI design. Compared to colour control tasks, both egocentric and allocentric TTC tasks activated left ventral premotor cortex/frontal operculum and inferior parietal cortex, the same areas that have previously been implicated in temporal attentional orienting. Despite differences in visual and cognitive demands, both TTC and temporal orienting paradigms encourage the use of temporally predictive information to guide behaviour, suggesting these areas may form a core network for temporal prediction. We also demonstrated that the temporal derivative of the perceptual index tau (tau-dot) held predictive value for making collision judgements and varied inversely with activity in primary visual cortex (V1). Specifically, V1 activity increased with the increasing likelihood of reporting a collision, suggesting top-down attentional modulation of early visual processing areas as a function of subjective collision. Finally, egocentric viewpoints provoked a response bias for reporting collisions, rather than no-collisions, reflecting increased caution for head-on approaches. Associated increases in SMA activity suggest motor preparation mechanisms were engaged, despite the perceptual nature of the task.

Detecting motor abnormalities in preterm infants

As a consequence of the fragility of various neural structures, preterm infants born at a low gestation and/or birthweight are at an increased risk of developing motor abnormalities. The lack of a reliable means of assessing motor integrity prevents early therapeutic intervention. In this paper, we propose a new method of assessing neonatal motor performance, namely the recording and subsequent analysis of intraoral sucking pressures generated when feeding nutritively. By measuring the infant's control of sucking in terms of a new development of tau theory, normal patterns of intraoral motor control were established for term infants. Using this same measure, the present study revealed irregularities in sucking control of preterm infants. When these findings were compared to a physiotherapist's assessment six months later, the preterm infants who sucked irregularly were found to be delayed in their motor development. Perhaps a goal-directed behaviour such as sucking control that can be measured objectively at a very young age, could be included as part of the neurological assessment of the preterm infant. More accurate classification of a preterm infant's movement abnormalities would allow for early therapeutic interventions to be realised when the infant is still acquiring the most basic of motor functions. (C) Springer-Verlag 2000.

Pleistocene glaciation events shape genetic structure across the range of the American lobster, Homarus americanus

A north/south discontinuity along the northeastern coast of North America in the genetic structure of the American lobster (Homarus americanus) was detected using a suite of 13 microsatellite loci assessed using spatial analyses. Population genetic data laid over existing data on physiographic changes and sea-surface temperatures were used to reconstruct the Pleistocene distribution of this species. A postglacial northern-edge colonization model best explains the relative genetic homogeneity of the northern region compared to the southern region centred in the Gulf of Maine. Population genetic analyses identified significant structure (range of standardized theta 0-0.02) but no significant evidence for isolation by distance. The novel application of spatial genetic analyses to a marine species allowed us to interpret these results by providing a greater insight into the evolutionary factors responsible for shaping the genetic structure of this species throughout is natural range.

Death Aesthetization in Contemporary Artistic Practices

Starting from the famous and enigmatic quotation of the Aristotle’s Poetics, who argues that the human has a natural desire and pleasure to see corpses if mediated by art, is intended to show the relationship between the attraction for the horror and some contemporary art practices surrounding the depiction of death, particularly with regard to the ultimate use of the human corpse as an artistic resource. Avoiding any kind of ethical approach or questioning of the limits of the artistic production, is meant to highlight the phenomenon through the examples brought out by the work of some contemporary artists such as Andy Warhol, Eric Fischl, Damien Hirst, Von Hagens, Andres Serrano, Joel-Peter Witkin and Teresa Margolles: From those who use the corpse in and turn it in something aesthetically pleasant, to others who turn human corpses in sculptures of scientific value, and further other kind of artists who assume the morbid and dramatic life of the corpse in their art production as something structural.

Thermophysical Properties of Amino Acid-Based Ionic Liquids

Ionic liquids (ILs) having either cations or anions derived from naturally occurring amino acids have been synthesized and characterized as amino acid-based ionic liquids (AAILs) In this work, the experimental measurements of the temperature dependence or density. viscosity, heat capacity, and thermal conductivity of several AAILs, namely, tributylmethylammonium serinate ([N-444][Ser], tributylmethylammonium taurmate ([N-444][Tau]) tributylmethylammonium lysinate a [N-444][ Lys]), tributylmethylammonium threonate ([N-444][Thr]), tetrabutylphosphonium serinate ([P-4444][Ser]), tetrabutylphosphonium taurmate ([P-4444][Tau]), tetrabutylphosphonium lysinate ([P-4444][Lys]), tetrabutylphosphonium threonate P-4444 Thr tetrabutylphosphonium prolinate P-4444 ((Pro(), tetrabutylphosphonium valinate ([P-4444][Val]), and tetrabutylphosphonium cysteinate ([P-4444][Cys]), are presented The influence of cations and anions on studied properties is discussed. On the basis of experimental data. the QSPR (quantitative structure property relationship) correlations and group contribution methods for thermophysical properties of AAILs have been developed, which form the basis for the development of the computer-aided molecular design (CAMD) of AAILs It has also been demonstrated that that the predictive data obtained by con elation methods ale in good agreement with the experimental data The correlations developed, herein. can thus be used to evaluate the studied thermophysical properties of AAILs for use in process design or in the CAMD of new AAILs

Sensory and intrinsic coordination of movement

A recently generalized theory of perceptual guidance (general tau theory) was used to analyse coordination in skilled movement. The theory posits that (i) guiding movement entails controlling closure of spatial and/or force gaps between effecters and goals, by sensing and regulating the tau s of the gaps (the time-to-closure at current closure rate), (ii) a principal way of coordinating movements is keeping the rs of different gaps in constant ratio (known as tau-coupling), and (iii) intrinsically paced movements are guided and coordinated by tau-coupling onto a tau-guide, tau(g), generated in the nervous system and described by the equation tau(g) = 0.5(t-T-2/t) where T is the duration of the body movement and t is the time from the start of the movement. Kinematic analysis of hand to mouth movements by human adults, with eyes open or closed, indicated that hand guidance was achieved by maintaining, during 80-85% of the movement, the tau-couplings tau(alpha)-tau(t) and tau(t)-tau(g), where tau(t) is tau of the hand-mouth gap, tau(alpha) is tau of the angular gap to be closed by steering the hand and tau(g) is an intrinsic tau-guide.

Judging the ‘passability’ of dynamic gaps in a virtual rugby environment

Affordances have recently been proposed as a guiding principle in perception–action research in sport (Fajen, Riley, & Turvey, 2009). In the present study, perception of the ’passability’ affordance of a gap between two approaching defenders in rugby is explored. A simplified rugby gap closure scenario was created using immersive, interactive virtual reality technology where 14 novice participants (attacker) judged the passability of the gap between two virtual defenders via a perceptual judgment (button press) task. The scenario was modeled according to tau theory (Lee, 1976) and a psychophysical function was fitted to the response data. Results revealed that a tau-based informational quantity could account for 82% of the variance in the data. Findings suggest that the passability affordance in this case, is defined by this variable and participants were able to use it in order to inform prospective judgments as to passability. These findings contribute to our understanding of affordances and how they may be defined in this particular sporting scenario; however, some limitations regarding methodology, such as decoupling perception and action are also acknowledged.

Prospective information for pass decisional behaviour in Rugby Union

Decision-making requires the perception of relevant information variables that emerge from the player–environment interaction. The purpose of the present article is to empirically assess whether players’ decisional behavior about which type of pass to make is influenced by the spatio-temporal variable tau. Time series positional data of rugby players were analyzed from video footage taken in real match scenarios. The tau of the distance motion gap between attacker and defender was calculated, along with the duration of the next pass. Results revealed that the initial tau value predicted 64% of the variance found in pass duration. A qualitative distinction of tau dynamics between two periods of the approach between the attacker and the defender was also observed. We argue that the time-to-contact between the attacker and the defender may yield information about future pass possibilities. Additionally, the informational fields constraining attacker–defender interaction may be viewed as a convergent channeling of possibilities towards a single pass solution.

Neonatal control of sucking pressures

Human newborns appear to regulate sucking pressure when bottle feeding by employing, with similar precision, the same principle of control evidenced by adults in skilled behavior, such as reaching (Lee et al., 1998a). In particular, the present study of 12 full-term newborn infants indicated that the intraoral sucking pressures followed an internal dynamic prototype - an intrinsic tau-guide. The intrinsic tau-guide, a recent hypothesis of general tau theory is a time-varying quantity, tau(g), assumed to be generated within the nervous system. It corresponds to some quantity (e.g., electrical charge), chang ing with a constant second-order temporal derivative from a rest level to a goal level, in the sense that tau(g) equals tau of the gap between the quantity and its goal level at each time t. (tau of a gap is the rime-to-closure of the gap at the current closure-rate.) According to the hypoth esis, the infant senses tau(p), the tau of the gap between the current intraoral pressure and its goal level, and regulates intraoral pressure so that tau(p) and tau(g) remain coupled in a constant ratio, k; i.e., tau(p) = k tau(g). With k in the range 0-1, the tau-coupling would result in a bell-shaped rate of change pressure profile, as was, in fact, found. More specifically, the high mean r(2) values obtained when regressing tau(p) on tau(g), for both the increasing and decreasing suction periods of the infants' suck, supported a strong tau-coupling between tau(p) and tau(g). The mean k values were significantly higher In the Increasing suction period, indicating that the ending of the movement was more forceful, a finding which makes sense given the different functions of the two periods of the suck.

Detecting Deceptive Movement in 1 vs. 1 Based on Global Body Displacement of a Rugby Player

A key to success in many sports stems from the ability to anticipate what a player is going to do next. In sporting duels such as a 1 vs. 1 in rugby, the attacker can try and beat the defender by using deceptive movement. Those strategies involve an evolution of the centre of mass (COM) in the medio-lateral plane, from a minimal state to maximal displacement just before the final reorientation. The aim of this work is to consider this displacement as a motion-gap, as outlined in Tau theory, as a potential variable that may specify deceptive movement and as a means of comparing anticipatory performance between mid-level players and novices in rugby. Using a virtual reality set-up, 8 mid-level rugby players (ML) and 8 novices (NOV) observed deceptive (DM) and non-deceptive movements (NDM). The global framework used an occlusion time paradigm with four occlusion times. Participants had to judge the final direction of the attacker after the different cuts-off. For each movement and at each occlusion time, we coupled the ability to predict the good final direction with the value of the COM displacement in the medio-lateral (COM M/L) plane or with the Tau of this parameter (Tau COM). Firstly, results show that the Tau COM is a more predictive optical variable than the simple COM M/L. Secondly, this optical variable Tau COM is used by both groups, and finally, with a specific methodology we showed that mid-level players have significantly better anticipatory ability than the novice group.

The mid-infrared dielectric function of NBCO in the a-b plane from 85 K to 300 K

Results are reported on the a-b plane dielectric function (epsilon) of thin-film c-axis NdBa2Cu3O7-delta with close to optimal oxygen doping (T-c similar to 90 K) in the mid-infrared (wavelength 3.392 mum) over the temperature range 85 K to 300 K. An attenuated total reflectance technique based on the excitation of surface plasmon polaritons is used. The results show that \epsilon (r)\ decreases quasi-linearly with increasing temperature, while Ei is invariant with temperature to within experimental uncertainties. Representative values are epsilon = [epsilon (r) + i epsilon (i)] = (-12.9 +/- 0.6) + i(23.0 +/- 1.5) at T similar to 295 K and epsilon = (-15.7 +/- 0.7) + i(23.5 +/- 1.1) at T similar to 90 K. The raw data an interpreted in terms of the generalized Drude model which gives effective scattering rates (1/tau*) that increase with temperature from about 3800 cm(-1) at 90 K to about 4300 cm(-1) at 295 K. There are indications of a superlinear T-dependence in the scattering, 1/tau*: a fit to a function of the form 1/tau* = A + BTalpha gives alpha = 2.8 +/- 0.7. The effective plasma frequency, omega (p)*, with an average value of approximately 21 000 cm(-1) was independent of temperature.

Temperature dependence of the mid-infrared dielectric function of YBCO in the a-b plane: a re-evaluation

The a-b plane dielectric function (epsilon) of c-axis YBa2Cu3O7-delta thin films with T-c > 85 K was measured at lambda = 3.392 mum in the temperature range 85-300 It, using an attenuated total reflectance (ATR) technique based on the excitation of surface plasmons, The results show that \epsilon (r)\ decreases quasi-linearly with increasing temperature, while Ei is invariant to temperature within experimental uncertainties. Typical values are epsilon (ab) = -23 + 16.5i at similar to 295 R and epsilon (ab) = -27 + 15.5i at similar to 90 K. A generalised Drude analysis yields effective scattering rates (1/tau*) that increase with temperature from similar to 1500 to similar to 1900 cm(-1). The temperature dependent rates best fit an equation of the form 1/tau* = a + bT(alpha) with alpha = 1.46 +/- 0.40. The effective plasma frequencies of w(p)* similar to 18,500 cm(-1) are almost independent of temperature. The uniquely detailed temperature dependence of the results confirm and consolidate data obtained by other groups using normal reflectance methods, but contradict our previously published ATR measurements. Technical shortcomings in the earlier work are identified as the source of the discrepancy. (C) 2000 Elsevier Science B.V. All rights reserved.