Gradual Attenuation Research Articles

The Realist Author and Sympathetic Imagination

The Realist Author and Sympathetic Imagination

Temporal trajectories of novel object recognition performance in mice exposed to intermittent hypoxia.

Intermittent hypoxia is one of the major perturbations of sleep-disordered breathing and has been causally implicated in neurocognitive deficits. However, the reversibility of such deficits is unclear.Male C57BL/6J mice were exposed to either intermittent hypoxia or room air for 3-240 days, and then half were randomly selected and allowed to recover in normoxic conditions for the same duration of the previous exposure. A novel object recognition (NOR) test was performed.NOR performance was stable over time in room air. Intermittent hypoxia induced significant reductions in recognition index that progressed over the first 45 days and stabilised thereafter. Normoxic recovery of recognition index was essentially complete and indistinguishable from room air in mice exposed to shorter intermittent hypoxia times (<90 days). However, significant residual deficits emerged after normoxic recovery following prolonged intermittent hypoxia exposures (p<0.01). In addition, gradual attenuation of the magnitude of recovery in recognition index occurred with increasingly longer intermittent hypoxia exposures (MANOVA p<0.0001).Intermittent hypoxia during the resting period reduces NOR performance in a time-dependent fashion. Reversal of NOR performance deficits is unlikely after prolonged intermittent hypoxia duration. These findings suggest that early recognition of sleep apnoea and effective treatment are critical for restoration of the adverse cognitive effects of the disease.

Specific features of accumulation of humus in technozems under poplar plantations in the conditions of the Western Donbass

Specific features of accumulation of humus in technozems under poplar plantations in the conditions of the Western Donbass

A Time-Based Analysis of Inflammation in Infants at Risk of Bronchopulmonary Dysplasia

To precisely delineate the timing and contribution of inflammation to bronchopulmonary dysplasia (BPD) in preterm infants during the neonatal period. Longitudinal study of blood inflammatory biomarkers (interleukin [IL]-6, IL-8, and granulocyte colony-stimulating factor) measured between birth and 42 days of age, at high temporal (daily) resolution, in infants born at or below 30 weeks of gestation. Cytokine predictors of BPD at 36 weeks postmenstrual age were adjusted for infant-specific and time-dependent factors, using hierarchical mixed effects regressions models. A total of 1518 data points were obtained in 62 infants (mean gestational age of 27 weeks). Infants who developed BPD later on presented increased inflammation after birth compared with infants without BPD. Inflammation was sustained, with gradual attenuation over 2 weeks (IL-8: OR: 6.5 [95% CI: 1.8-24]; granulocyte colony-stimulating factor: 3.3 [1.5-7.6]) and was higher in boys and in infants of lower birth weight. This inflammation preceded the clinical increased requirement in supplemental oxygen characteristic of BPD, and preceded the peak occurrence of neonatal sepsis or necrotizing enterocolitis. Systemic inflammation occurs early in the neonatal period and precedes clinical symptoms in infants with BPD. These data provide a discrete vulnerability window period, supporting a role for targeted intensive care interventions during the early phase of BPD.

Demonstration of 136 dB dynamic range capability for a simultaneous dual optical band CAOS camera.

For the first time, proposed and demonstrated is a simultaneous dual optical band coded access optical sensor (CAOS) camera design suited for extreme contrast multispectral bright target scenarios. Deploying a digital micromirror devices (DMDs)-based time-frequency agile pixels CAOS-mode within a two point detector spatially and spectrally isolating framework, this imager simultaneously and independently detects pixel selective image information for two different broad spectral bands that further undergo independent spectral image data extraction via finer-tuned wavelength filtering using all-optical or CAOS-mode electronic filters. A proof-of-concept visible-near infrared band CAOS imager is successfully demonstrated using a target scene containing LEDs and engaging narrowband optical filters. In addition, using the CAOS-mode, demonstrated is the RF domain simultaneous color content monitoring of a white light LED image pixel. Also proposed is the use of a higher bit count analog-to-digital converter (ADC) with both range and sampling duration parameter control along with a larger data set electronic DSP to extract higher DSP gain and realize additional noise suppression. Using a 16-bit ADC and 2,097,152 point fast Fourier transform (FFT) digital signal processing (DSP) for a 633 nm laser engaged test target scene that is subject to nearly 7 decades (107) of gradual optical attenuation, the experimental camera demonstrates an agile pixel extreme dynamic range of 136 dB, which is a 56 dB improvement over the previous CAOS-imaging demonstrations.

«АВАНГРАД»: ВОЛГОГРАДСКИЙ ПЕРЕСТРОЕЧНЫЙ И ПОСТСОВЕТСКИЙ ПЕРФОРМАНС (1986–2005)1

The article aims to reconstruct systematically the history of the Volgograd performance, trace the lineage and interferences, the role of the major art-festivals in the emergence of new generations of artists, as well as to disclose variability of procedural art-practices in Volgograd from 1986 to 2005. Summing up the performance review of the Volgograd two decades (mid-1980s to mid-2000s), the author notes that it was not a coher- ent movement or systematic process, and was not institutionalized due to the lack of a system of commercial galleries, inspiring artistic process in Moscow and St. Petersburg. A gradual attenuation of the Square as a social and cultural education and place of attraction for artists, localized in the heart of the city, caused a gradual centrifugal movement towards the outlying, uninhabited, abandoned spaces and places of pilgrimage (the graveyard of ships, Krasnoslobodskaya kosa, Moratnike), which was associated with their romanticize, aestheticization, by a certain opacity. However, throughout the period under review we can identify several General trends: the desire of artists to theatrical, carnival, spectacularity, as well as spontaneous and impro- vised action.

Drinking to ease the burden: a cross-sectional study on trauma, alcohol abuse and psychopathology in a post-conflict context.

BackgroundIt is likely that alcohol use and abuse increase during and after violent conflicts. The most prominent explanation of this phenomenon has been referred to as self-medication hypothesis. It predicts that psychotropic substances are consumed to deal with conflict-related psychic strains and trauma. In northern Uganda, a region that has been affected by a devastating civil war and is characterized by high levels of alcohol abuse we examined the associations between war-trauma, childhood maltreatment and problems related to alcohol use. Deducing from the self-medication hypothesis we assumed alcohol consumption moderates the relationship between trauma-exposure and psychopathology.MethodsA cross-sectional epidemiological survey targeting war-affected families in post-conflict northern Uganda included data of male (n = 304) and female (n = 365) guardians. We used standardized questionnaires in an interview format to collect data on the guardians’ socio-demography, trauma-exposure, alcohol consumption and symptoms of alcohol abuse, PTSD and depression.ResultsSymptoms of current alcohol use disorders were present in 46 % of the male and 1 % of the female respondents. A multiple regression model revealed the unique contributions of emotional abuse in the families of origin and trauma experienced outside the family-context in the prediction of men’s alcohol-related symptoms. We found that alcohol consumption moderated the dose-effect relationship between trauma-exposure and symptoms of depression and PTSD. Significant interactions indicated that men who reported more alcohol-related problems experienced less increase in symptoms of PTSD and depression with increasing trauma-exposure.ConclusionsThe gradual attenuation of the dose-effect the more alcohol-related problems were reported is consistent with the self-medication hypothesis. Hence, the functionality of alcohol consumption has to be considered when designing and implementing addiction treatment in post-conflict contexts.

Controllable synthesis of reduced graphene oxide

A controllable fabrication of reduced Graphite oxide (RGO) via different alcohols was reported. Characterized and analyzed by X-ray diffraction, fourier transform infrared spectroscopy, UV–visible spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and cyclic voltammetry, the chemical and structural properties, together with the electro-conductivities of the RGOs fabricated by ethanol (EtOH), 1-propanol (PrOH), 1-butanol (BuOH) and benzyl alcohol (PhOH) were investigated systemically. The results showed that the reduction degree of GO was strongly dependent on the type of alcohol. The strongest reducibility of PhOH was attributed to the special activity of the benzyl hydrogen of PhOH in comparison with the other primary alcohols. Meanwhile, the reducibility of the primary alcohols decreased with the elongation of carbon chain, which might be explained by the gradual attenuation of hydrogen donation ability and the increase of steric hindrance. The reducibility order of the investigated alcohols was determined as RGO(PhOH) > RGO(EtOH) > RGO(PrOH) > RGO(BuOH), indicating the potential controllability of the RGOs reduced by different alcohols for special use. In addition, the electrical conductivity of RGO(PhOH) was found to be similar to that of Graphite.

Light sheet microscopy reveals more gradual light attenuation in light-green versus dark-green soybean leaves.

Light wavelengths preferentially absorbed by chlorophyll (chl) often display steep absorption gradients. This over-saturates photosynthesis in upper chloroplasts and deprives lower chloroplasts of blue and red light. Reducing chl content could create a more even leaf light distribution and thereby increase leaf light-use efficiency and overall canopy photosynthesis. This was tested on soybean cultivar 'Clark' (WT) and a near-isogenic chl b deficient mutant, Y11y11, grown in controlled environment chambers and in the field. Light attenuation was quantified using a novel approach involving light sheet microscopy. Leaf adaxial and abaxial surfaces were illuminated separately with blue, red, and green wavelengths, and chl fluorescence was detected orthogonally to the illumination plane. Relative fluorescence was significantly greater in deeper layers of the Y11y11 mesophyll than in WT, with the greatest differences in blue, then red, and finally green light when illuminated from the adaxial surface. Modeled relative photosynthesis based on chlorophyll profiles and Beer's Law predicted less steep gradients in mutant relative photosynthesis rates compared to WT. Although photosynthetic light-use efficiency was greater in the field-grown mutant with ~50% lower chl, light-use efficiency was lower in the mutant when grown in chambers where chl was ~80% reduced. This difference is probably due to pleiotropic effects of the mutation that accompany very severe reductions in chlorophyll and may warrant further testing in other low-chl lines.

Assessment of the attenuation of an intra-abdominal vein by use of a silicone-polyacrylic acid gradual venous occlusion device in dogs and cats.

OBJECTIVE To evaluate the closure rate and completeness of closure for a silicone-polyacrylic acid gradual venous occlusion device placed around an intra-abdominal vein to simulate gradual occlusion of an extrahepatic portosystemic shunt. ANIMALS 3 purpose-bred cats and 2 purpose-bred dogs. PROCEDURES The device was surgically placed around an external (cats) or internal (dogs) iliac vein. Computed tomographic angiography was performed at the time of surgery and 2, 4, and 6 weeks after surgery. Ultrasonographic examinations of blood flow through the vein within the device were performed at the time of surgery and at weekly intervals thereafter. Dogs were euthanized 6 weeks after surgery, and the external iliac veins were harvested for histologic examination. RESULTS The prototype gradual venous occlusion device was successfully placed in all animals, and all animals recovered without complications following the placement procedure. The vessel was completely occluded in 2 cats by 6 weeks after surgery, as determined on the basis of results of CT and ultrasonography; there was incomplete occlusion with a luminal diameter of 1.5 mm in the other cat by 6 weeks after surgery. The vessel was completely occluded in both dogs by 6 weeks after surgery. Histologic examination of the external iliac veins obtained from the dogs revealed minimal inflammation of the vessel wall and no thrombus formation. CONCLUSIONS AND CLINICAL RELEVANCE The prototype device induced gradual attenuation of an intra-abdominal vessel over a 6-week period. This device may provide another option for gradual occlusion of extrahepatic portosystemic shunts.

Evolutionary characteristics of morbilliviruses during serial passages in vitro: Gradual attenuation of virus virulence.

The genus Morbillivirus is classified into the family Paramyxoviridae, and is composed of 6 members, namely measles virus (MV), rinderpest virus (RPV), peste-des-petits-ruminants virus (PPRV), canine distemper virus (CDV), phocine distemper virus (PDV) and cetacean morbillivirus (CeMV). The MV, RPV, PPRV and CDV have been successfully attenuated through their serial passages in vitro for the production of live vaccines. It has been demonstrated that the morbilliviral virulence in animals was progressively attenuated with their consecutive passages in vitro. However, only a few reports were involved in explanation of an attenuation-related mechanism on them until many years after the establishment of a quasispecies theory. RNA virus quasispecies arise from rapid evolution of viruses with high mutation rate during genomic replication, and play an important role in gradual loss of viral virulence by serial passages. Here, we overviewed the development of live-attenuated vaccine strains against morbilliviruses by consecutive passages in vitro, and further discussed a related mechanism concerning the relationship between virulence attenuation and viral evolution.

Dispersal and the Movius Line: Testing the effect of dispersal on population density through simulation

Abstract It has been proposed that a strong relationship exists between the population size and density of Pleistocene hominins and their competence in making stone tools. Here we focus on the first ‘Out of Africa’ dispersal, 1.8 Ma ago, and the idea that it might have featured lower population density and the fragmentation of hominin groups in areas furthest away from the point of origin. As a result, these distant populations in Central and East Asia and Europe would not be able to sustain sophisticated technological knowledge and reverted to a pattern of simpler stone-knapping techniques. This process could have led to the establishment of the ‘Movius Line’ and other long-lasting continental-scale patterns in the spatial distribution of Lower Palaeolithic stone technology. Here we report on a simulation developed to evaluate if, and under what conditions, the early ‘Out of Africa’ dispersal could lead to such a demographic pattern. The model comprises a dynamic environmental reconstruction of Old World vegetation in the timeframe 2.5–0.25 Ma coupled with a standard biological model of population growth and dispersal. The spatial distribution of population density is recorded over the course of the simulation. We demonstrate that, under a wide sweep of both environmental and behavioural parameter values, and across a range of scenarios that vary the role of disease and the availability of alternative crossing points between Africa, Europe and Asia, the demographic consequence of dispersal is not a gradual attenuation of the population size away from the point of origin but a pattern of ecologically driven local variation in population density. The methodology presented opens a new route to understand the phenomenon of the Movius Line and other large-scale spatio-temporal patterns in the archaeological record and provides a new insight into the debate on the relationship between demographics and cultural complexity. This study also highlights the potential of simulation studies for testing complex conceptual models and the importance of building reference frameworks based on known proxies in order to achieve more rigorous model development in Palaeolithic archaeology and beyond.

Behavior of plastic and metal ameroid constrictors during in vitro incubation in physiologic solutions of varying glucose concentration

The objective of this study was to evaluate the influence of ameroid constrictor (AC) composition as well as glucose concentration in the surrounding fluid on the rate and completeness of AC closure. In a pilot study, four ACs (two metal, two plastic) were incubated in a solution containing 100mg/dL glucose, and in a follow-up study, two additional ACs (one metal, one plastic) were incubated in a solution of 100mg/dL glucose and six ACs (three metal, three plastic) were incubated in a solution of 50mg/dL glucose. Dimensions of the ACs were analyzed weekly for 57days. No significant difference was found in the rate or overall proportionate closure for either metal versus plastic ACs or ACs incubated in 50mg/dL versus 100mg/dL glucose. As there was no statistically significant difference in the proportionate closure of metal and plastic ACs, both types are clinically suitable for gradual attenuation of portosystemic shunts in animal patients. The lack of a significant difference in rate and completeness of closure of ACs incubated in different concentrations of glucose provides evidence that the glucose concentration of the surrounding fluid likely does not have a significant effect on AC closure. However, a significant difference in the proportionate closure of ACs occurred within the first week of the study between constrictors incubated in 50mg/dL glucose and those incubated in 100mg/dL glucose, and additional studies are indicated to determine the significance of this early difference in vivo.

Anatomy of outbursts and quiescent activity of Comet 29P/Schwassmann–Wachmann

Detailed morphological and photometric characterisation of Comet 29P in the optical region is presented comprising: (a) multi-filter observations of the outburst coma in 2010–2012 with the 2.0-m Faulkes Telescopes (FT); (b) high-cadence, high-precision photometry in May–September 2014; and (c) HST observations in March 1996 (WFPC2/F702W filter). Outbursts appear to be explosive in that: the rise to maximum light is short-lived; the expanding coma fits a model in which ejecta are produced in a singular event and expand into space with uniform velocity; and the motion of condensations within the outburst coma indicate a common onset time and origin. The bright outburst of 2010 February 2 generated a dust coma exhibiting expansion speeds up to 0.257±0.013kms−1 consistent with acceleration of cometary grains close to the nucleus driven by sublimating CO ice and N2 ice at 24±6K. Material ejected ∼1d after this outburst exhibited a V–R colour gradient: redder towards the main outflow, bluer in the opposite sense; potentially arising from differences in spectral emission (from gas), light scattering (particle size), and spectral reflectance (composition). B–V, V–R and R–I colour images revealed colour/compositional differences in near-nucleus structures and the evolution of the expanding coma, which brightened by ∼30% within 5–6days of the outburst. Broadband photometry indicated a general reddening coma with time (change in B–V from +0.76 to +0.83; V–SDSS-r′ from 0.25 to +0.31 in 14d). SDSS-r′–SDSS-i′ photometry indicated gradual spectral attenuation at >700nm. Asymmetric, fan-shaped comae, characteristic of 29P, potentially form when the expanding cloud from an outburst is shielded by the nucleus. Rotational-gradient filtered HST and FT images show unusual 2-fold and 4-fold symmetry involving oppositely-directed radial outflows moving at up to 0.15kms−1: possibly an indication of material escaping from fissures along the perimeter of a crustal ‘plate’ when dislodged by pressure build-up in the subsurface. Pairs of outbursts separated in time by 52–65d took place in 2010, 2011, and 2012 exhibiting similar coma outflow patterns indicative of outbursts repeating a second time from the same source, and suggesting a nuclear rotation period of 59±4 (s.e.)d. The escape velocity of the nucleus is sufficiently high (0.013–0.023kms−1) that a significant fraction of ejecta falls back onto its surface, the action of which, we suggest, re-forms the crust and may trigger outbursts from nearby sites (e.g. triple events of February 2010, and May 2014). A short-lived (<1d) anomalous brightening of 0.36±0.12mag observed on 2014 July 21 during quiescence may have arisen from an especially weak mini-outburst in which most of the ejected material failed to reach escape velocity. During quiescence in 2014, Comet 29P fluctuated in brightness over time-scales of 2–10d by up to ±0.25mag, probably via local jet activity continuing to feed the faint persistent inner coma. 29P also exhibited weak outbursts of <1mag amplitude during quiescence and these will generally be missed by observers. Image analysis methodology tracking the locus of the coma photocentre with increasing photometric aperture size is used to quantify the directional motion of cometary haloes within 1–2d of an outburst.

Attenuation of the oestrogen positive feedback mechanism with the age in postmenopausal women

It has been reported that the positive feedback mechanism of oestrogens and progesterone is preserved, although attenuated, in late postmenopausal years. Whether this is also true for the positive feedback effect of oestrogens alone has not been investigated. Prospective intervention study. Thirty healthy postmenopausal women. The women were divided into three groups according to the years since menopause (group I: 2-8 years, group II: 9-17 years, group III: 18-25 years). They were studied during a period of 41 days. Two acute experiments (EP) of exogenous oestradiol, given via skin patches, were performed from days 1 to 7 (EP1) and from days 35 to 41 (EP2) to induce an LH surge. Between the two experiments (days 7-34), oestradiol was given at the dose of 100 μg every 3 days, while oral progesterone was added from day 21 to day 34 in order to simulate a luteal phase. Blood samples were taken every 6 h during EP1 and EP2 as well as on days 8, 13, 20, 21, 27 and 34. FSH, LH, oestradiol and progesterone were measured in all blood samples. An LH surge occurred as a result of the oestradiol positive feedback mechanism in group I and in group II, in both EP1 and EP2. Peak LH values during the surge were significantly lower in group II than in group I in both experiments. None of the patients in group III displayed an LH surge. These results demonstrate for the first time a gradual attenuation of the pituitary response to oestrogenic provocation over a certain period following the menopause, with complete abolition after 20 years. It is suggested that the reserves of pituitary gonadotrophs diminish with age.

Management of ventricular arrhythmias in suspected channelopathies.

Although structural heart disease remains the predominant substrate for ventricular arrhythmia, channelopathies including long QT syndrome (LQTS), short QT syndrome (SQTS), Brugada syndrome (BrS), catecholaminergic polymorphic ventricular tachycardia (CPVT), and early repolarization syndrome (ERS) are less common but important contributing entities. These etiologies require specific therapies potentially contrary to empirical management of arrhythmias associated with structural heart disease. Conventional therapy including antiarrhythmic drug therapy may not only fail to resolve unstable arrhythmias but worsen them. Additionally, channelopathy patients with implantable cardioverter defibrillators (ICD) and arrhythmic storms represent a major challenge, and the acute care team needs to be cognizant of unique circumstances that require specific acute therapies beyond empirical advanced life support algorithm recommendations.1 Successful and considered acute management of ventricular arrhythmias is contingent on a number of variables, including knowledge of the cardiac substrate or potential substrate; form, mechanism, and precipitants of ventricular arrhythmias; and acute effect of potential therapies. In the longer term, an understanding of the natural history of the channelopathy along with the efficacy of long-term therapy will lead to superior outcomes. This review will present the risk of ventricular arrhythmias associated with these uncommon entities, the evolving understanding of the mechanism of arrhythmia, and the mechanistic basis of therapies along with a clinical approach to summarize the evidence pertaining to acute and long-term management. Patients with a prolonged QT interval are at risk of sudden cardiac death (SCD) due to Torsade de Pointes (TdP; Figure 1). Most patients with congenital LQTS are asymptomatic and diagnosed incidentally on electrocardiogram screening or following family screening. However, syncope, aborted SCD, or SCD may be the first presentation. Most arrhythmic events in congenital LQT1 occur during physical or emotional stress, at rest or in association with sudden auditory stimulation in LQT2, and during sleep or rest in LQT3 …

The progressive adaptation of a georgian isolate of African swine fever virus to vero cells leads to a gradual attenuation of virulence in swine corresponding to major modifications of the viral genome.

African swine fever virus (ASFV) causes a contagious and often lethal disease of feral and domestic swine. Experimental vaccines derived from naturally occurring, genetically modified, or cell culture-adapted ASFV have been evaluated, but no commercial vaccine is available to control African swine fever (ASF). We report here the genotypic and phenotypic analysis of viruses obtained at different passages during the process of adaptation of a virulent ASFV field isolate from the Republic of Georgia (ASFV-G) to grow in cultured cell lines. ASFV-G was successively passaged 110 times in Vero cells. Viruses obtained at passages 30, 60, 80, and 110 were evaluated in vitro for the ability to replicate in Vero cells and primary swine macrophages cultures and in vivo for assessing virulence in swine. Replication of ASFV-G in Vero cells increased with successive passages, corresponding to a decreased replication in primary swine macrophages cultures. In vivo, progressive loss of virus virulence was observed with increased passages in Vero cells, and complete attenuation of ASFV-G was observed at passage 110. Infection of swine with the fully attenuated virus did not confer protection against challenge with virulent parental ASFV-G. Full-length sequence analysis of each of these viruses revealed significant deletions that gradually accumulated in specific areas at the right and left variable ends of the genome. Mutations that result in amino acid substitutions and frameshift mutations were also observed, though in a rather limited number of genes. The potential importance of these genetic changes in virus adaptation/attenuation is discussed. The main problem in controlling ASF is the lack of vaccines. Attempts to produce vaccines by adaptation of ASFV to cultured cell lines have been made. These attempts led to the production of attenuated viruses that conferred only homologous protection. Specifics regarding adaptation of these isolates to cell cultures have been insufficiently described. Details like the numbers of passages required to obtain attenuated viruses, genetic modifications introduced into the virus genomes along passages, and the extent of attenuation and induced protective efficacy are not readily available. In this study, we assessed the changes that lead to decreased growth in swine macrophages and to attenuation in swine. Loss of virulence, probably associated with limited replication in vivo, may lead to the lack of protective immunity in swine observed after challenge. This report provides valuable information that can be used to further the understanding of ASFV gene function, virus attenuation, and protection against infection.

EEG predictors of covert vigilant attention

Objective. The present study addressed the question whether neurophysiological signals exhibit characteristic modulations preceding a miss in a covert vigilant attention task which mimics a natural environment in which critical stimuli may appear in the periphery of the visual field. Approach. Subjective, behavioural and encephalographic (EEG) data of 12 participants performing a modified Mackworth Clock task were obtained and analysed offline. The stimulus consisted of a pointer performing regular ticks in a clockwise sequence across 42 dots arranged in a circle. Participants were requested to covertly attend to the pointer and press a response button as quickly as possible in the event of a jump, a rare and random event. Main results. Significant increases in response latencies and decreases in the detection rates were found as a function of time-on-task, a characteristic effect of sustained attention tasks known as the vigilance decrement. Subjective sleepiness showed a significant increase over the duration of the experiment. Increased activity in the α-frequency range (8–14 Hz) was observed emerging and gradually accumulating 10 s before a missed target. Additionally, a significant gradual attenuation of the P3 event-related component was found to antecede misses by 5 s. Significance. The results corroborate recent findings that behavioural errors are presaged by specific neurophysiological activity and demonstrate that lapses of attention can be predicted in a covert setting up to 10 s in advance reinforcing the prospective use of brain–computer interface (BCI) technology for the detection of waning vigilance in real-world scenarios. Combining these findings with real-time single-trial analysis from BCI may pave the way for cognitive states monitoring systems able to determine the current, and predict the near-future development of the brain's attentional processes.

Anesthesia and evoked responses in neurosurgery.

Anesthesia and evoked responses in neurosurgery.

Improvements on Remote Diffuser-Phosphor-Packaged Light-Emitting Diode Systems

By modifying traditional remote phosphor-diffuser-packaged light-emitting diode systems, we have managed to increase the luminous efficacy from 145.7 to 162.3 lm/W. One mechanism responsible for this achievement is associated with randomizing the directions of light beams transmitting through an interior diffuser, whose position is optimized based on an overall merit. The other mechanism is identified as the gradual attenuation of the undesirable blue-ring image along the distance from the diffuser toward the phosphor base. The identification of these two mechanisms is verified by luminous efficacy measurements, 3-D image plots, and combined Monte Carlo algorithm ray tracing simulation results. In addition, merits related to correlated color temperatures and issues pertaining to costs are briefly discussed.