An integrated microdevice was developed to couple on-chip SPE to separation by channel electrochromatography. An acrylate-based monolith was synthesized within a glass microdevice by photoinitiated polymerization. It was used for both separation and preconcentration by direct injection on the head of the stationary phase or by confining the preconcentration step in a given zone of the stationary phase. The composition of the polymerization mixture was chosen to achieve a monolithic material containing both hydrophobic and charged moieties to ensure an electroosmotic flow for separation. As a consequence the extraction procedure occurs via hydrophobic and ionic interactions. Neutral, ionizable and charged compounds were successfully preconcentrated and separated within the microdevice through electrochromatographic mechanisms, highlighting the versatility of this device. The performance of the integrated microdevice was demonstrated with the preconcentration and separation of a mixture of PAHs for which a signal enhancement factor (SEF) of 270 was achieved within 120 s of preconcentration. In the case of charged and ionizable compounds, according to the electrolyte composition, contributions of both reverse-phase and ion-exchange mechanisms were used to perform effective electrochromatographic preconcentration. A SEF of 250 was obtained for the model-charged compound within 20 s of preconcentration. Finally, the potentials of on-chip preconcentrate and separate both neutral and ionized compounds have been demonstrated using a mixture of model compounds.

Individual differences in anxiety provide a differential predisposition to develop neuropsychiatric disorders. The neurochemical underpinnings of anxiety remain elusive, particularly in deep structures, such as the nucleus accumbens (NAc) whose involvement in anxiety is being increasingly recognized. We examined the associations between the neurochemical profile of human NAc metabolites involved in neural excitation and inhibition and inter-individual variation in temperamental and situational anxiety. Twenty-seven healthy 20-30 years-old human males were phenotyped with questionnaires for state and trait anxiety (State-Trait Anxiety Inventory, STAI), social anxiety (Liebowitz Social Anxiety Scale), negative mood (Beck Depression Inventory, BDI) and fatigue (Mental and Physical State Energy and Fatigue Scales, SEF). Using proton magnetic resonance spectroscopy (¹H-MRS) at 7 Tesla (7T), we measured metabolite levels for glutamate, glutamine, GABA and taurine in the NAc. Salivary cortisol was also measured. Strikingly, trait anxiety was negatively associated with NAc taurine content. Perceived situational stress was negatively associated with NAc GABA, while positively with the Glu/GABA ratio. No correlation was observed between NAc taurine or GABA and other phenotypic variables examined (i.e., state anxiety, social anxiety, negative mood, or cortisol), except for a negative correlation between taurine and state physical fatigue. This first 7T study of NAc neurochemistry shows relevant metabolite associations with individual variation in anxiety traits and situational stress and state anxiety measurements. The novel identified association between NAc taurine levels and trait anxiety may pave the way for clinical studies aimed at identifying new treatments for anxiety and related disorders.

BACKGROUND

Decreased spinal excitability contributes to the immobilizing effects of halogenated ethers during general anaesthesia. Recurrent spinal responses such as F-waves reflect spinal excitability and are suppressed by volatile anaesthetics. To evaluate whether F-waves are suitable for monitoring immobility, the concentration-dependent effects of sevoflurane on F-waves were compared with effects on the Bispectral Index (BIS). The predictive power of all parameters for movement responses to noxious stimuli was tested. In addition, the effect of the noxious stimulus itself on F-waves was investigated.

METHODS

In 28 patients, F-waves were recorded during sevoflurane anaesthesia at a frequency of 0.2 Hz at the lower limb. To insert a laryngeal mask, the sevoflurane concentration was initially increased to approximately 4%, which caused a complete extinction of F-waves. The sevoflurane concentration was then reduced until the F-waves recovered. BIS and spectral edge frequency (SEF(95)) were recorded continuously. The t(1/2ke0) and EC(50) values of the F-wave persistence and amplitude were calculated using a standard pharmacokinetic-pharmacodynamic model. During decreasing sevoflurane concentration motor responses to tetanic electrical stimulation (50 Hz, 60 mA, 5 s, volar forearm) were tested in seven patients and MAC(tetanus) was calculated using logistic regression.

RESULTS

Sevoflurane reduces the F-wave amplitude with an EC(50) of 0.79 vol% at a far lower concentration than the calculated MAC(tetanus) (1.5 vol%), whereas the F-wave persistence yields an EC(50) of 1.4 vol%. Spinal and EEG parameters predicted the motor responses to movement better than chance alone, but did not differ significantly from each other.

CONCLUSIONS

F-waves, especially the F-wave amplitude, cannot be used to predict movement to noxious stimuli during sevoflurane anaesthesia because they are almost completely suppressed at subclinical sevoflurane concentrations. Either the particular motoneurone pool (the largest motoneurones) assessed by F-waves is not involved in generating movement to painful stimuli or direct effects on motoneurone excitability are not involved in the suppression of movement to painful stimuli by sevoflurane.

To use subcutaneous ultrasonography to differentiate legs with edema because of obesity-related functional venous insufficiency (FVIob), immobility-related FVI (FVIim), secondary lymphedema (LE), LE complicated by obesity (LEob), and LE complicated by immobility (LEim).

Ninety-nine legs with edema (16 FVIob, 32 FVIim, 22 LE, 9 LEob, and 20 LEim), and 10 normal legs were examined. Subcutaneous tissue ultrasonography was performed at eight points (medial, lateral, upper, lower, thigh, and calf) in each leg. Subcutaneous echogenicity (SEG) and subcutaneous echo-free space (SEFS) were assessed, and each graded as 0, 1, and 2 according to their severity.

In normal legs, SEG and SEFS were graded 0 in almost all parts of the leg. SEG was diffusely increased in FVIob, whereas SEG was increased in accordance with gravity in FVIim (upper medial thigh, 0.6 ± 0.5 vs lower medial calf, 1.2 ± 0.4; P < .001). In LE, SEG was increased in the medial side, particularly evident in upper thigh (upper medial thigh, 1.1 ± 0.4 vs upper lateral thigh, 0.6 ± 0.6; P < .01). SEFS was increased in accordance with gravity in all of these legs (FVIob: upper medial thigh, 0.2 ± 0.4 vs lower medial calf, 0.7 ± 0.8; P = .05; FVIim: upper medial thigh, 0.1 ± 0.2 vs lower medial calf, 1.3 ± 0.7; P < .0001; LE: upper medial thigh, 0.4 ± 0.7 vs lower medial calf, 0.9 ± 0.9; P < .05). The increases of SEG and SEFS in legs with LEob or LEim were diffuse and similar. As determined via stepwise logistic regression analyses, the increases in SEG in the upper medial thigh and SEFS in the lower medial thigh in LE cases, the increases in SEG in the upper lateral thigh and SEFS in the lower lateral thigh in cases with obesity-related leg edema (ie, FVIob and LEob), and the increase in SEFS in the lower lateral calf in cases with immobility-related leg edema (ie, FVIim and LEim) were determined to be significant factors to characterize each leg edema.

Differences in the extent and distribution of SEG and SEFS might help in differentiating LE from FVIob and FVIim, although assessment of LE complicated by obesity vs immobility remains difficult.

Flying mammals present unique intestinal adaptations, such as lower intestinal surface area than nonflying mammals, and they compensate for this with higher paracellular absorption of glucose. There is no consensus about the mechanistic bases for this physiological phenomenon. The surface area of the small intestine is a key determinant of the absorptive capacity by both the transcellular and the paracellular pathways; thus, information about intestinal surface area and micro-anatomical structure can help explain differences among species in absorptive capacity. In order to elucidate a possible mechanism for the high paracellular nutrient absorption in bats, we performed a comparative analysis of intestinal villi architecture and enterocyte size and number in microchiropterans and rodents. We collected data from intestines of six bat species and five rodent species using hematoxylin and eosin staining and histological measurements. For the analysis we added measurements from published studies employing similar methodology, making in total a comparison of nine species each of rodents and bats. Bats presented shorter intestines than rodents. After correction for body size differences, bats had ~41% less nominal surface area (NSA) than rodents. Villous enhancement of surface area (SEF) was ~64% greater in bats than in rodents, mainly because of longer villi and a greater density of villi in bat intestines. Both taxa exhibited similar enterocyte diameter. Bats exceeded rodents by ~103% in enterocyte density per cm² NSA, but they do not significantly differ in total number of enterocytes per whole animal. In addition, there is a correlation between SEF and clearance per cm² NSA of L-arabinose, a nonactively transported paracellular probe. We infer that an increased enterocyte density per cm² NSA corresponds to increased density of tight junctions per cm² NSA, which provides a partial mechanistic explanation for understanding the high paracellular absorption observed in bats compared to nonflying mammals.

Surgical stress activates the amygdala and secretion of norepinephrine, both involved in memory and unconscious processing of emotionally negative information. This study examined surgically induced facilitation of implicit learning of emotionally negative information. Thirty patients undergoing laparoscopic cholecystectomy under general anesthesia were tested. Between 2 and 4 h after surgery, patients provided word-associates to cues previously presented (old) or not previously presented during anesthesia (new). Half the cues were emotionally negative and half neutral. Patients took less time to provide correct associates to old emotionally negative cues than to new emotionally negative cues (p < 0.05). Spectral edge frequency (SEF) of cerebral activity during surgery converged with this finding. Implicit learning during general anesthesia may be stronger for emotionally negative information and is detected by SE.

The present study investigated the test-retest reliability of magnetoencephalography (MEG) source localization of somatosensory evoked fields (SEFs) over an extended time period. Five healthy subjects were stimulated pneumatically at the first and fifth digit in two sessions spaced several months apart. At each location 400 stimuli were presented. The validation of the results was performed by overlay of the dipole localizations into the individual anatomic structure of the subjects' cortex by the use of magnetic resonance images (MRIs). The source localizations of the SEF component were found to be highly reproducible. The mean standard deviation of the dipole locations of the first digit was 1.55 mm in the x-, 1.55 mm in the y- and 3.49 mm in the z-direction. The mean standard deviation of the fifth digit was 3.69 mm in the x-, 4.27 mm in the y- and 6.60 mm in the z-direction. These results support the use of MEG recordings combined with MRI as an adequate method to define the organization of the human primary somatosensory cortex and provide a useful approach to the rapid detection of neuroplasticity.

BACKGROUND

The electroencephalographic Narcotrend Index (NI) may potentially help to titrate sedative medication during diagnostic and therapeutic procedures in children.

METHODS

With local ethics committee approval and informed parental consent, 31 patients, aged 8.9 +/- 4.3 years, scheduled for elective upper gastrointestinal endoscopy were enrolled in this prospective, double-blinded observational study. Initially, patients received a single dose of intravenous piritramide 0.1 mg x kg(-1), followed by propofol 2 mg x kg(-1) and, if necessary, additional propofol doses (0.5 mg x kg(-1)) to achieve and maintain a level of deep sedation throughout the procedure. Sedation was assessed by the University of Michigan Sedation Scale (UMSS). We investigated the relationship between depth of sedation, and the NI, and the classical EEG parameters (cEEG), total EEG power (Power), spectral edge (SEF) and median frequency, and relative power in the beta, alpha, theta and delta bands. The performance of the NI and cEEG parameters was evaluated by prediction probability (P(K)), receiver operating characteristic (ROC) and Spearman rank order correlation analysis.

RESULTS

Mean P(K) values for NI (0.88) vs UMSS were higher than for the other cEEG parameters, except for Power (0.82) and SEF(0.81). Spearman correlation analysis revealed superiority of the NI over all cEEG parameters. The area under the curve for the NI was 0.93, which was superior to all other EEG parameters beside Power (0.86) and relative power in alpha (0.82).

CONCLUSIONS

The results of this study suggest that the NI may be an objective nondisruptive tool for assessment of hypnotic depth in children under propofol-induced procedural sedation.

A novel DNA sensor for the detection of the Escherichia coli O157:H7 (E. coli O157:H7) eaeA gene was constructed using surface enhanced fluorescence (SEF). The spacing distance dependence nature of Au@Ag nanorods surface enhanced fluorescence was investigated when the cy3-labled single strand DNA(ssDNA) and the stem-loop DNA probe modified on the nanorods was co-hybridized. The result revealed that the fluorescence intensity reached the maximum value with the spacing distance of about 10nm between cy3 and the Au@Ag nanorods surface. Based on this result, a fluorescence "ON/OFF" switch for detecting the eaeA gene of E. coli O157:H7 was constructed. Under optimal conditions, the DNA sensor produced a linear range from 10(-17) to 10(-11) M with a correlation coefficient of 0.9947 and a detection limit of 3.33×10(-18) M, and was also found to be specific in targeting eaeA. The DNA sensor demonstrated a new strategy of combining eaeA recognition and Au@Ag nanorods for fluorescence signal enhancement, and increased sensitivity in the detection of bacterial specific genes.

Alzheimer's disease (AD) sometimes presents with prominent executive dysfunction and associated prefrontal cortex atrophy. The impact of such executive deficits on episodic memory performance as well as their neural correlates in AD, however, remains unclear. The aim of the current study was to investigate episodic memory and brain atrophy in AD patients with relatively spared executive functioning (SEF-AD; n = 12) and AD patients with relatively impaired executive functioning (IEF-AD; n = 23). We also compared the AD subgroups with a group of behavioral-variant frontotemporal dementia patients (bvFTD; n = 22), who typically exhibit significant executive deficits, and age-matched healthy controls (n = 38). On cognitive testing, the three patient groups showed comparable memory profiles on standard episodic memory tests, with significant impairment relative to controls. Voxel-based morphometry analyses revealed extensive prefrontal and medial temporal lobe atrophy in IEF-AD and bvFTD, whereas this was limited to the middle frontal gyrus and hippocampus in SEF-AD. Moreover, the additional prefrontal atrophy in IEF-AD and bvFTD correlated with memory performance, whereas this was not the case for SEF-AD. These findings indicate that IEF-AD patients show prefrontal atrophy in regions similar to bvFTD, and suggest that this contributes to episodic memory performance. This has implications for the differential diagnosis of bvFTD and subtypes of AD.

The coronary sinus (CS) vessel serves as a conduit for the deployment of percutaneous transvenous mitral annuloplasty (PTMA) devices for the treatment of functional mitral regurgitation. Characterization of the mechanical response of the CS is an important step towards an understanding of tissue-device interaction in PTMA intervention. The purpose of this study was to investigate the mechanical properties of the porcine CS using the pressure-inflation test and constitutively model the wall behavior using a four fiber family strain energy function (SEF). The results showed that the CS exhibited an S-shaped pressure-radius response and could be dilated up to 88% at a pressure of 80mmHg. Excellent results from model fitting indicated that the four fiber family SEF could capture the experimental data well and could be used in future numerical simulations of tissue-device interaction. In addition, a histological study was performed to identify the micro-structure of the CS wall. We found a high content of striated myocardial fibers (SMFs) surrounding the CS wall, which was also mainly composed of SMFs, while the content of smooth muscle cells was very low. Elastin and collagen fibers were highly concentrated in the luminal and outer layers and sparsely distributed in the medial layer of the CS wall. These structural and mechanical properties of the CS should be taken into consideration in future PTMA device designs.

Sclerosing epithelioid fibrosarcoma (SEF) is a rare sarcoma of low-grade malignancy. There has been no report to describe the comparison of histological features of SEF between primary and metastatic lesions in spite of high local recurrence rate. We report the histological changes and increasing Ki-67 labeling index of the primary and metastatic lesions of SEF. The patient was a 31-year-old man. At 18, a tumor in the abdominal wall was excised. At 23, the tumor recurred which was removed again. At 30, he was referred to our hospital because of swelling and pain in the chest. Histological examination of the chest wall tumor showed epithelioid cells arranged like alveolar pattern with dense collagen stroma. These findings were consistent with those of SEF. Abdominal and the rib tumors showed the same immunohistochemistrical expression. It is noteworthy that the tumor cells of the rib lesion showed increased cellularity, and its Ki-67 activity was higher as compared with the abdominal tumor, suggestive of progression of malignancy of SEF.

A gentamicin-resistant isolate of Staphylococcus aureus producing staphylococcal enterotoxin F (SEF) was isolated from a burn unit nurse during three episodes of toxic-shock syndrome (TSS). The nurse's reciprocal titer of antibodies to SEF was less than or equal to 5 during the three episodes, and when the titer rose to 1,000 no further relapses occurred despite continued colonization. The unusual antibiotic susceptibility pattern of the organism enabled demonstration of its spread. During four months, 12 (41%) of 29 burn unit patients, three other burn unit nurses, and a household contact of the nurse with TSS became colonized. None, including two patients whose initial reciprocal titers were less than or equal to 5, developed TSS. This experience illustrates significant cross-transmission of a TSS-associated strain and a temporal association of antibodies to SEF with cessation of recurrences of TSS. Additional factors must explain why other individuals lacking antibodies to SEF did not develop TSS.

The objective of this study is to evaluate the usefulness of bispectral index (BIS), spectral edge frequency 95% (SEF) and median frequency (MED) in relation to a simple descriptive scale (SDS) as indicators of anaesthetic depth at different desflurane concentrations in swine. Sixteen pigs were randomly allocated to four groups. Electroencephalograms (EEG) were recorded during desflurane anaesthesia, and BIS, SEF and MED were calculated from the EEG. The agent was administered in pure oxygen at 1, 1.25, 1.5 and 1.7 MAC in randomized order. Anaesthetic depth was evaluated on a SDS. BIS decreased significantly (P<0.001) at the different anaesthetic dosages used. SEF decreased significantly (P<0.001) from basal to 1 MAC of desflurane. MED decreased significantly (P<0.001) from basal to 1 MAC and from 1 to 1.75 MAC. Good correlation was seen between SDS scores and BIS values and between SDS scores and MED values. BIS appeared to be useful to predict changes in anaesthetic depth at clinically used dosages of inhalant anaesthesia.

Our ability to regulate behavior based on past experience has thus far been examined using single movements. However, natural behavior typically involves a sequence of movements. Here, we examined the effect of previous trial type on the concurrent planning of sequential saccades using a unique paradigm. The task consisted of two trial types: no-shift trials, which implicitly encouraged the concurrent preparation of the second saccade in a subsequent trial; and target-shift trials, which implicitly discouraged the same in the next trial. Using the intersaccadic interval as an index of concurrent planning, we found evidence for context-based preparation of sequential saccades. We also used functional MRI-guided, single-pulse, transcranial magnetic stimulation on human subjects to test the role of the supplementary eye field (SEF) in the proactive control of sequential eye movements. Results showed that (i) stimulating the SEF in the previous trial disrupted the previous trial type-based preparation of the second saccade in the nonstimulated current trial, (ii) stimulating the SEF in the current trial rectified the disruptive effect caused by stimulation in the previous trial, and (iii) stimulating the SEF facilitated the preparation of second saccades based on previous trial type even when the previous trial was not stimulated. Taken together, we show how the human SEF is causally involved in proactive preparation of sequential saccades.

Somatosensory Evoked Potentials (SEPs) and Somatosensory Evoked magnetic Fields (SEFs) to median nerve stimulation at wrist were recorded in 5 healthy subjects and the components between 15 and 30 ms after the stimulus were evaluated on the hemiscalp contralateral to the stimulated wrist. SEPs were measured by means of a 32-channel recorder and compared with SEFs obtained via multiple measurements with a 4-channel sensor. Equivalent dipole localization was carried out for the magnetic components peaking at about 15, 20 and 24 ms. The scalp distribution of SEPs, illustrated by bit mapped color images, were qualitatively explained by three separate sources. The first is described as a tangentially oriented dipole placed behind the Central Sulcus and responsible for the parietal N20-"late P25" waves and for the frontal P20-N30 ones. The second is represented by a radieal dipole placed just in front of the Central Sulcus and pointing towards the motor strip, responsible for the rolandic P22 component. The third is just behind the Central Sulcus and is radieally oriented towards the surface of the postcentral sensory area for the "early P25" parietal wave. The SEFs distributions, illustrated by color isofield contour maps, were quantitatively explained by a unique tangential dipole localized, with good resolution, well behind the Sulcus for the 15 ms waves and slightly frontal to this site for the waves peaking at around 20 and 24 ms. The equivalent dipole has been localized at a depth of about 5 cm (15 ms component), 2 cm (20 ms components) and 4 cm (24 ms component), across the studied subjects. It is stressed that the dipole responsible for the magnetic pattern is likely to be the same tangential dipole responsible for a part of the electric pattern. Due to their radieal orientation, the other two dipoles, proposed for the SEPs maps, would be mostly undetectable by a magnetic investigation.

A total of 29 strains of Salmonella enterica belonging to seven serovars isolated from human, animals and birds were used to study the occurrence of Salmonella fimbriae genes (sef and pef) by PCR amplification technique using their specific primers. All the strains (15) of S. Enteritidis were found to carry both sef and pef genes irrespective of the source of isolation. S. Typhimurium strains were found to harbour only pef genes, while S. Gallinarum strains harboured only sef genes. Other serovars namely, S. Newport, S. Kentucky, S. Weltevreden and S. Indiana were negative for both pef and sef genes. The importance of fimbriae in the pathogenesis of salmonellosis is suggested.

The nucleotide sequence of a 3 kb region immediately upstream of the sef operon of Salmonella enteritidis was determined. A 1230 base pair insertion sequence which shared sequence identity >> 75%) with members of the IS3 family was revealed. This element, designated IS1230, had almost identical (90% identity) terminal inverted repeats to Escherichia coli IS3 but unlike other IS3-like sequences lacked the two characteristic open reading frames which encode the putative transposase. S. enteritidis possessed only one copy of this insertion sequence although Southern hybridisation analysis of restriction digests of genomic DNA revealed another fragment located in a region different from the sef operon which hybridised weakly which suggested the presence of an IS1230 homologue. The distribution of IS1230 and IS1230-like elements was shown to be widespread amongst salmonellas and the patterns of restriction fragments which hybridised differed significantly between Salmonella serotypes and it is suggested that IS1230 has potential for development as a differential diagnostic tool.

The DNA sequence of the chromosomal gene cluster encoding the SEF14 fimbriae of Salmonella enterica serovar Enteritidis was determined. Five contiguous open reading frames, sefABCDE, were identified. The sefE gene shared significant homology with araC-like positive regulators. Serovar-associated virulence plasmid (SAP) genes orf7,8,9 and pefI were identified immediately adjacent to the sef operon. The pefI gene encoded a putative regulator of the Plasmid-encoded fimbrial antigen (PEF) expression. The entire sef--pef region, flanked by two IS-like elements, was inserted adjacent to leuX that encoded a transfer RNA molecule. The organisation of this region was suggestive of a classic pathogenicity islet. Southern hybridisation confirmed two copies of the SAP derived orf7,8,9 and pefI region in S. Enteritidis, one in the chromosome and one on the SAP. Of other group D Salmonella, only S. Blegdam and S. Moscow harboured both chromosomal and plasmid copies of pefI--orf9 region although polymorphism was evident.

Increasing concern has been recently raised on the possible effects of soy-derived phyto-oestrogens on the development of cognitive functions in infants. However, limited studies have been conducted to date, and no data have been made available for determining whether infant soy formula can affect normal development of the human brain. We compared electroencephalographic (EEG) spectral power derived from high-density recordings of infants fed milk-based or soy formula (46 fed milk-based formula and 39 fed soy formula) at 3 and 6 months of age. The spectral parameters included absolute power, relative power and spectral edge frequency (SEF) at 85%, 90% and 95% levels. The frequency domain contained four bands (0.1-3, 3-6, 6-9 and 9-12 Hz). EEG signals were collected from eight brain areas in each hemisphere. The results showed that the highest spectral power was mainly distributed in the low-frequency bands and was predominant in the frontal and anterior temporal areas. None of the spectral variables significantly differed between the soy- and milk-fed infants (anova, all P>> 0.2). However, significant effects were indicated on the SEFs for factors of sex, age and brain area (all P < 0.01). Hemispheric differences in the absolute and relative power were also indicated. Our results suggest that the EEG power spectral development of soy-fed infants does not differ from that of infants fed milk-based formula. In addition, EEG spectral development appears more advanced in female than in male infants at 6 months.

Many neurons in the macaque supplementary eye field (SEF) exhibit object-centered spatial selectivity, firing at different rates when the monkey plans a saccade to the left or right end of a horizontal bar. Is this property natural to the SEF or is it a product of specialized training in the laboratory? To answer this question, we monitored the activity of single SEF neurons in two monkeys before and after training to select eye-movement targets by an object-centered rule. During stage 1, the monkeys performed a color delayed-match-to-sample (DMS) task in which a red or green central cue dictated an eye movement to the matching end of a horizontal bar. Many neurons at this stage exhibited object-centered spatial selectivity. During stage 2, the monkeys performed a color-conditional object-centered task in which a green or red central cue instructed an eye movement to the left or right end of a gray bar. More neurons exhibited object-centered spatial selectivity during this stage than during stage 1. During stage 3, the monkeys again performed the color DMS task. The fraction of neurons exhibiting object-centered spatial selectivity remained at a level comparable to that observed during stage 2 and above that observed during stage 1. Thus object-centered spatial selectivity was present before training on an object-centered rule, was enhanced as a product of object-centered training, and outlasted active use of an object-centered rule. We conclude that neural representations of object-centered space, naturally present in the primate brain, can be sharpened by training.

Choices are made with varying degrees of confidence, a cognitive signal representing the subjective belief in the optimality of the choice. Confidence has been mostly studied in the context of perceptual judgments, in which choice accuracy can be measured using objective criteria. Here, we study confidence in subjective value-based decisions. We recorded in the supplementary eye field (SEF) of monkeys performing a gambling task, where they had to use subjective criteria for placing bets. We found neural signals in the SEF that explicitly represent choice confidence independent from reward expectation. This confidence signal appeared after the choice and diminished before the choice outcome. Most of this neuronal activity was negatively correlated with confidence, and was strongest in trials on which the monkey spontaneously withdrew his choice. Such confidence-related activity indicates that the SEF not only guides saccade selection, but also evaluates the likelihood that the choice was optimal. This internal evaluation influences decisions concerning the willingness to bear later costs that follow from the choice or to avoid them. More generally, our findings indicate that choice confidence is an integral component of all forms of decision-making, whether they are based on perceptual evidence or on value estimations.

Thin solid films of bis benzimidazo perylene (AzoPTCD) were fabricated using physical vapor deposition (PVD) technique. Thermal stability and integrity of the AzoPTCD PVD films during the fabrication ( approximately 400 degrees C at 10(-6) Torr) were monitored by Raman scattering. Complementary thermogravimetric results showed that thermal degradation of AzoPTCD occurs at 675 degrees C. The growth of the PVD films was established through UV-vis absorption spectroscopy, and the surface morphology was surveyed by atomic force microscopy (AFM) as a function of the mass thickness. The AzoPTCD molecular organization in these PVD films was determined using the selection rules of infrared absorption spectroscopy (transmission and reflection-absorption modes). Despite the molecular packing, X-ray diffraction revealed that the PVD films are amorphous. Theoretical calculations (density functional theory, B3LYP) were used to assign the vibrational modes in the infrared and Raman spectra. Metallic nanostructures, able to sustain localized surface plasmons (LSP) were used to achieve surface-enhanced resonance Raman scattering (SERRS) and surface-enhanced fluorescence (SEF).