Voxels with a probability of 0 2 of containing CSF in any of the

Voxels with a probability of 0.2 of containing CSF in any of the subjects were excluded from the non-CSF mask, which was applied to the statistical maps as an explicit mask. In that way, areas of partial volumes, such as those surrounding the ventricles and the borders around the cortex, were masked out. The sequential Hochberg correction (Hochberg, 1988) was used to correct for multiple comparisons. This procedure uses a step-up ranking of the p values and TGF-beta inhibitor review then corrects for the p value threshold by dividing it by the rank

of the comparison. A voxel was considered significant only if it exceeded the corrected statistical threshold (p < 0.05). The statistical parametric maps are superimposed on a template T1 image, providing an anatomical informative reference. In addition, for the learning group, we performed a mixed-design ANOVA of 2 × 2 (gender × scan time) with repeated measures on the second factor. This design allowed selleck chemicals us, by observing the interaction effect, to identify voxels that were changed differently over time for the males and females in the learning group. The authors wish to thank the Raymond and Beverly Sackler Insitute for Biophysics, the Israel Science Foundation, and the Strauss Center for Computational Neuroimaging of Tel Aviv University for the purchase and maintenance of the 7T MRI system. Y.A. wishes to thank the Israel Science Foundation (ISF

grant 994/08), and Future and Emerging Technologies (FET) Programme within the Seventh Framework Programme for Research of the European Commission (FET-Open, “CONNECT” project), grant 238292. “
“Dementia is estimated to affect 25 million people worldwide, of whom 30%–70% have Alzheimer’s

disease (AD) and 10% frontotemporal dementia (FTD). Neuropathological evidence points to a neuronal/synaptic poliencephalopathy (Braak et al., 2000), with the disease beginning in the gray matter with accumulation of misfolded beta amyloid and/or tau protein and progressing along either extant fiber pathways via secondary Wallerian degeneration, disconnection, and loss of signaling, axonal reaction, and postsynaptic dendrite retraction ( Seeley et al., 2009). Atrophy patterns captured from longitudinal magnetic resonance imaging (MRI) ( Apostolova et al., 2007 and Thompson et al., 2003) via segmentation, atlas-based parcellation ( Wu et al., 2007), and volumetric analysis (e.g., FreeSurfer [ Fischl et al., 2002], FMRIB Software Library [FSL] [ Smith et al., 2004], and statistical parametric mapping [SPM] [ Klauschen et al., 2009]) indicate that progression occurs along vulnerable fiber pathways rather than by proximity ( Villain et al., 2008, Englund et al., 1988 and Kuczynski et al., 2010). This view is supported by recent studies showing alterations in brain networks due to neurodegeneration ( He et al., 2008 and Lo et al., 2010).

Another variation is an intersectional technique that relies on s

Another variation is an intersectional technique that relies on split binary systems, pioneered by the split-GAL4 system (Luan et al., 2006b) that was recently optimized (Pfeiffer et al., 2010) (Figure 3D). The GAL4 transcription factor is split into two hemidrivers, each of

which is driven by separate regulatory elements. Obeticholic Acid Where the expression domains overlap, both halves of GAL4 are expressed, heterodimerize via leucine zippers, and reconstitute a functional activator. A similar split strategy was recently developed for LexA (Ting et al., 2011). Another intersectional strategy combines GAL4 with Flp recombinase (Golic and Lindquist, 1989), each driven by separate regulatory elements. The expression of transactivator, responder, or repressor depends on recombinase activity removing an intervening stop cassette (Struhl and Basler, 1993). Alternatively, GAL80 can be activated by Flp-In so that only cells that express GAL4

and not Flp are capable of expressing a UAS-responder element (Bohm et al., 2010) (Figure 3E). Many combinations of the orthogonal binary expression systems and Flp recombinase can be envisioned (Potter et al., 2010, Bohm et al., 2010, Yagi et al., 2010 and Potter and Luo, 2011). The development of new recombinases and alternative target sites further broadens the combinatorial palette (Nern et al., 2011 and Hadjieconomou et al., 2011). The binary SNS-032 cost systems described in the previous section can be used to overexpress reporters to label neuronal subpopulations or subcompartments of these neurons (Table 1). Numerous fluorescent reporters are available. To label the entire cytoplasmic compartment, fluorescent proteins can be overexpressed (Yeh the et al., 1995, Halfon et al., 2002 and Pfeiffer et al., 2010). Fluorescent markers fused to membrane targeted domains label the cell outline (Lee and Luo, 1999, Ritzenthaler et al., 2000, Ye et al., 2007, Yu et al., 2009a and Pfeiffer et al., 2010). Fusions with synaptic vesicle proteins predominantly label the presynaptic compartment of synaptic contacts (Estes et al., 2000, Zhang et al.,

2002 and Rolls et al., 2007). Active zones can be labeled with bruchpilot-GFP (Wagh et al., 2006) or cacophony-GFP (Kawasaki et al., 2004). While there is no generic marker for postsynaptic sites, Denmark (Nicolaï et al., 2010) or Dscam[exon 17.1] (Wang et al., 2004) preferentially labels dendrites. Fusions to neurotransmitter receptor proteins such as UAS-Rdl-HA and UAS-Dα7-GFP can also be used to identify synapses (Sánchez-Soriano et al., 2005 and Leiss et al., 2009). Markers that label subcellular organelles include fluorescent proteins fused to targeting elements specific for mitochondria, endoplasmatic reticulum, Golgi, and nucleus (LaJeunesse et al., 2004 and Yasunaga et al., 2006). A fusion with horseradish peroxidase is useful for transmission electron microscopy (Larsen et al., 2003 and Watts et al., 2004).

, 2004, Xu et al , 2005, Deák et al , 2006, Kesavan et al , 2007,

, 2004, Xu et al., 2005, Deák et al., 2006, Kesavan et al., 2007, Bretou et al., 2008, Lu et al., 2008, Stein et al., 2009, Fdez et al., 2010, Guzman et al., 2010, Ngatchou et al., 2010, Risselada et al., 2011 and Shi et al., 2012). However, no direct test of this conclusion in a physiological context has been presented. Here, we demonstrate that the SNARE

TMRs are unlikely to be essential for fusion since lipid-anchored syntaxin-1 and synaptobrevin-2 both were fully competent to support synaptic vesicle fusion in a physiological context. The lipid-anchored SNAREs completely rescued the impairment in spontaneous fusion in syntaxin- and synaptobrevin-deficient neurons, http://www.selleckchem.com/screening/pfizer-licensed-library.html and partially rescued KU-57788 chemical structure evoked release. Although lipid-anchored SNAREs were not as efficient as wild-type SNAREs in restoring the amplitude of evoked release in SNARE-deficient neurons, they reversed the impaired synchronization of evoked release, suggesting that impaired expression levels or incomplete targeting may in part account for the partial activity of lipid-anchored SNAREs in rescuing evoked release (Figure 4). Our results

suggest that a prevalent model whereby the SNARE TMRs are an essential component of the fusion machinery may need to be revised, and that SNAREs primarily—and maybe exclusively—operate as force generators for membrane fusion. According to this revised model, dehydrating the membrane surfaces of opposing membranes by forcing them closely together during 3-mercaptopyruvate sulfurtransferase SNARE-complex assembly may be sufficient to destabilize the phospholipid membrane surfaces and to induce fusion. Our data are consistent with the observation that protein-free liposomes form electrophysiologically “normal” fusion pores without protein components lining the pores (reviewed in Jahn et al., 2003) and argue against a necessary, direct role of SNARE TMRs in fusion-pore formation. It is tempting to speculate that the continued

association of the SM protein Munc18-1 with SNARE complexes during all stages of fusion (Khvotchev et al., 2007, Rathore et al., 2010 and Zhou et al., 2013) may reflect a contribution of Munc18-1 to the dehydration of the fusing membranes, thereby allowing spontaneous lipid mixing when SNARE-complex assembly forces membranes into close proximity, although no direct evidence supports this notion at present. The experiments in which we tested the functionality of either lipid-anchored syntaxin-1 (Figures 2 and 3) or lipid-anchored synaptobrevin-2 (Figures 4, 5, and 6) did not exclude the possibility that the SNARE TMRs still play a contributory role in fusion whereby only one of the two SNAREs (i.e., either syntaxin-1 or synaptobrevin) needs to be TMR anchored for fusion.

, 2006) Thus, when dopamine level is low, such as when bursting

, 2006). Thus, when dopamine level is low, such as when bursting activities are insufficient, it fails to produce and reinforce these networks’ connectivity underlying habit formation. Other than the striatum, reduced bursting of DA neurons may also affect activities of structures such as the PFC of which lesion of the medial infralimbic area was reported to impair expression

of a learned habit (Coutureau and Killcross, 2003). Studies have shown that tonic dopamine KPT330 concentration in the prefrontal area, likely due to the relatively slower dopamine reuptake (Seamans and Yang, 2004), may be affected by previous phasic dopamine release (Matsuda et al., 2006). The presence of background dopamine signal converts LTD to potentiation. This “priming” requires time to develop and requires D1 and D2 receptors, both of which have low affinity to dopamine. It is very likely that this phasic release-induced “priming” could also be affected by the amount of DA neurons bursting, thus, by blunting of DA response. It will be of great interest to dissect the various roles of those different brain regions in habit formation in future studies. It is also important for future research to further analyze the contributions of NMDARs within different dopamine subpopulations, BMS 907351 and temporally within

different phases of habit learning. The potential subregional circuitry within the DA neuron populations in the VTA and SNr regions can be highly crucial for integrating distinct cortical and subcortical inputs (Grace et al., 2007, Lammel et al., 2011 and Lisman and Grace, 2005). Thus, it is conceivable that additional subregional-specific manipulations and analyses could further elucidate

how the glutamatergic regulation of DA neurons, as revealed by our current study, modulates habit formation. In summary our study has provided several important insights about NMDAR in DA neurons and habit learning. First, NMDARs in DA neurons Oxygenase are required for learning habits, including appetitive lever pressing and spatial navigational habits. Second, the dependence of habit learning on NMDARs in DA neurons was observed in both positively and negatively reinforced trainings. Third, DA neurons lacking the NMDARs can still form the cue-reward association but with greatly reduced phasic activity as well as conditioned response robustness. Taken together, our results suggest that the NMDARs in DA neurons are an important modulator of DA neurons’ response robustness in cue-reward association and an essential element underpinning habit learning. Mice carrying alleles of NMDAR1 flanked by loxP sites (fNR1) were bred with Slc63a Cre transgenic mice. Offspring were genotyped by PCR for both the Cre transgene and for the floxed NMDAR1 (fNR1) locus.

When k equals 1, then all responses are given equal weight, and t

When k equals 1, then all responses are given equal weight, and this pooling operation is equivalent to averaging. As k increases, the most active neural populations will increasingly dominate the pooled response. The model fits suggested that a single value of k (k = 68, toward the maximizing

side of the spectrum) could account for behavioral performance on both distributed and focal cue trials NSC 683864 purchase because the stimulus location evoking the highest response will dominate the pooling. Recall that the contrast of the stimulus in each quadrant was assigned a random pedestal value ranging from 0% to 84%. Thus, on distributed cue trials, one of the nontarget locations should evoke the largest response on average, leading to an increase in the contrast change required

for accurate discrimination (a larger Δc). On focused cue trials, the location evoking the largest response almost always corresponded to the target because of the attention-induced additive shift in the BOLD response ( Figure 1a). Although this pooling rule could account for the results, it is critical to note that like response enhancement and noise reduction, selective pooling is not sufficient. Rather, it was the pooling rule combined with additive response enhancement that led to improved perceptual acuity with focused selleck products attention (and the same principle would apply, given other forms of response enhancement as well; see main text, last paragraph starting on page 843). This finding is particularly exciting because it suggests that biased pooling rules might enable attentional gating by amplifying relatively modest changes in metabolically expensive response enhancement, thus maximizing perceptual selectivity while minimizing energy aminophylline expenditure. One major remaining question concerns the extent to

which the value of k is systematically tied to the properties of the stimulus array. In a simple case in which only one stimulus is presented in a known position in the visual field, pooling is largely irrelevant because there is only one location associated with an evoked response during each interval. In such sparse stimulus arrays, response enhancement and noise reduction probably play a dominant role. However, k should grow with the number of competing stimuli, because maximizing the influence of attention-enhanced responses should become increasingly important as distractor-evoked responses threaten to drown out relevant neural signals. Thus, a key avenue for future research will be to determine how k changes with the size and complexity of the search set and to understand whether and when k reaches asymptote (which may determine the upper limit on the effectiveness of pooling as a means of facilitating selection).

Nevertheless, our results argue against this model for the follow

Nevertheless, our results argue against this model for the following reasons. First, a “switching model” in which a single spotlight travels in space predicts that it should be faster to switch attention between patterns that are close together than between patterns that are farther apart. We found the opposite (Figure 2 and Figure 3S). Second, our control experiment demonstrates an increase in RTs associated with changes

find more in one translating RDP when its associated change probability is reduced and the change probability in the other pattern is increased. We argued that a switching spotlight should produce a RT distribution that approximates the pooled RTs distributions corresponding to both probabilities. However, we found that the pooled distribution has a higher mean than the one corresponding to 0.5-change probability targets of the main experiment.

In fact, the RTs distribution corresponding to targets with the largest change probability (0.8) was similar to the one corresponding to 0.5-change probability targets. This suggest that during the main experiment the animals devoted the same amount of attention to each target as to BI2536 the 0.8-target of the control experiment, and that the level of attention to any of the RDPs never decreased to values similar or close to the one corresponding to the lowest (0.2) change probability target. For a switch model to account for these data animals had to switch attention between the 50-targets in ∼12 ms or less (determined by shortening the RTs corresponding to the 20-targets and repeating the pooling and comparison of RT distribution until it became nonsignificant). This is half of the estimated shift time

from our data and much shorter than the lowest value reported for stimulus driven Carnitine palmitoyltransferase II (35 ms) and voluntary (∼200 ms) attention shifts in humans ( Horowitz et al., 2009). Third, and most importantly, we found that responses during tracking were decreased relative to those during attend-RF and attend-fixation when the translating stimuli circumvented the RF pattern. A switching spotlight of attention cannot account for these results. Instead, our findings suggest a relative suppression of responses to the RF pattern when it falls between the two attended RDPs. This strongly argues against models in which a single spotlight of attention travels in space, or rapidly turns on and off at the location of tracked objects ( Pylyshyn and Annan, 2006). This model proposes that when attending to multiple stimuli the spotlight of attention can split into multiple foci corresponding to each relevant stimulus and excluding distracters in between (Castiello and Umiltà, 1992, Cavanagh and Alvarez, 2005, Howe et al., 2010 and Niebergall et al., 2010). The animals’ behavioral performance in the main tracking task show that they attended to both translating RDPs.

3 Hz for different BLP frequencies (δ, θ, α, β, γ) and different

3 Hz for different BLP frequencies (δ, θ, α, β, γ) and different RSN. Repeated-measures ANOVAs with network (visual, auditory, dorsal attention) and condition (fixation and movie) as main Sirolimus datasheet factors showed a significant reduction of the total interdependence in movie as compared

to fixation. This reduction was significant in α BLP (main effect condition (F1,33 = 14.19, p < 0.001, pη2 = 0.30)), in β BLP (main effect condition (F1,33 = 5.21, p = 0.04, pη2 = 0.12)) (Figure 2B) while it did not reach significance in δ (F1,33 = 3.45, p = 0.07), θ (F1,33 = 1.24, p = 0.27) and γ BLP (F1,33 = 1.24, p = 0.30) (Figure S2). The decrement in total interdependence was consistent across different RSN (interaction network × Condition, both for α and β band [all p values > 0.05]). Next, we considered modulation of total interdependence estimated across-RSN nodes, as opposed to within-RSN as in the previous analysis. Again, there was a significant reduction during movie with respect to fixation in α BLP (main effect condition (F1,33 = 5.66, p = 0.02, pη2 = 0.15)). Importantly, this effect was consistent across networks (interaction network × condition, p > 0.05). No significant modulation was detected in the other frequency bands (all p values > 0.05) (Figure S3). Overall, in agreement

with previous MEG reports (Brookes et al., 2011b, de Pasquale et al., 2010, de Pasquale et al., 2012 and Hipp et al., 2012), functional coupling between nodes of RSN was characterized by slow fluctuations of BLP at about 0.1 Hz. Watching a movie leads to first an overall decrement of inter-nodal interaction at frequencies < 0.3 Hz, mainly in buy Alectinib the α BLP, both within and across networks. Hence, visual stimulation seems to promote a reduction of functional connectivity as captured by α (and β for within-RSN) BLP interactions. Next, we considered whole-brain changes in the topography and strength of BLP correlation induced by movie watching. To map voxelwise modulation, BLP correlation maps were computed between a RSN node and the rest of the brain assuming the stationarity

of BLP correlation (de Pasquale et al., 2010), using the Pearson product moment formula (Experimental Procedures). Individual node Z score correlation maps were averaged across runs and subjects to compute group-level maps in each condition (fixation, movie). To minimize the effect of field spread, difference maps between conditions were computed and then averaged across RSN nodes to yield voxel-wise BLP difference correlation maps between movie and fixation (Supplemental Information for details). Figure 3A shows α BLP correlation changes from fixation to movie obtained by averaging all nodes in the visual network. Note the widespread decrement of correlation broadly across occipital visual cortex, bilaterally, extending into posterior parietal cortex (dorsal attention network) and temporal cortex (auditory network), especially in the right hemisphere.

1 and family B: II 2 and II 4) at the Center for Human Genome Var

1 and family B: II.2 and II.4) at the Center for Human Genome Variation (CHGV) at Duke University, Durham, NC. Prior to sequencing, target regions were captured using the SureSelect

Human All Exon technology (Aligent Technologies). This technology captures consensus coding sequence exonic regions and flanking intronic regions totaling ∼38 Mb of genomic DNA. The resulting short-sequence reads were aligned to the reference genome (NCBI human genome VX-770 mouse assembly build 36; Ensembl core database release 50_361 [Hubbard et al., 2009]) using the Burrows-Wheeler Alignment (BWA) tool (Li and Durbin, 2009). After accounting for PCR duplicates (removed using the Picard software: http://picard.sourceforge.net) and reads that did not align check details to captured regions of the reference genome, the average coverage for these three samples was ∼71× and each sample had >95% of the bases covered. A base within the 37.8 Mb captured

region was defined as covered if ≥5 short reads spanned this nucleotide (Table S10). Genetic differences between each patient genome and the reference genome were identified using the SAMtools variant calling program (Li et al., 2009), which identifies both single-nucleotide variants (SNVs) and small indels. We then used the SequenceVariantAnalyzer software (SVA) (Ge et al., 2011) to annotate all identified variants. SVA was also used to apply quality control filters to the variants identified by SAMtools. High-quality SNVs were obtained using the following criteria: consensus score ≥20, SNP quality score ≥20, and reads supporting SNP ≥3. High-quality indels were obtained using the following criteria: consensus L-NAME HCl score ≥20, indel quality score

≥50, ratio of (reads supporting variant/reads supporting reference): 0.2–5.0, and reads supporting indel ≥3. The exomes of one of the individuals of family C (II.3) and four individuals of family D (II.1, II.2, II.4, and II.5) were captured using the Agilent SureSelect all exon kit V3 (approximately 51.9 Mb of target sequences) and then sequenced in pair ends (2 × 100 bp) on the Illumina HiSeq2000 (v3 chemistry; 3 exomes/lane format) at the McGill University Genome Quebec Innovation Center (Montreal, Canada). The sequences were aligned and the variants were called using GATK (DePristo et al., 2011). After removal of duplicate reads, using Picard, we obtained an average coverage of >80× per target base, with 95% of the target bases being covered at ≥10×. Only variants that meet all the following criteria were considered: base coverage ≥8×, reads supporting the variant ≥3, and ratio of reads supporting variant/reads supporting reference ≥20%. Variants were then annotated using Annovar (Wang et al., 2010). Genotyping of the p.F362V variant in 1,160 controls was performed in the Center for Human Genome Variation at Duke University (Durham, NC).

Parallels to some of these effects are numerous in the human lite

Parallels to some of these effects are numerous in the human literature.

histone deacetylase activity Cognitive processing of music is not in itself dependent on active or formal musical training, as even people without any special musical experience clearly have a good understanding of music, and show sensitivity to musical relationships like tonality (Krumhansl et al., 1982; Toiviainen and Krumhansl, 2003) and meter (Hannon et al., 2004). The evolutionary basis of music is still under debate (Fitch, 2006; Hauser and McDermott, 2003; McDermott, 2008), but there is no doubt that music originates very early in human history (Conard et al., 2009). Behaviorally, attention and sensitivity to music has been clearly demonstrated in studies of infants, who consistently show precocious abilities to detect musical regularities and deviations from them, as shown for features such as tuning of chords (Folland et al., 2012), the pitch of the missing fundamental in complex

sounds (He and Trainor, 2009), and musical phrase structure (Jusczyk and Krumhansl, 1993). The contingencies of musical relationships are believed to be learned implicitly through statistical learning at an early age via appropriate exposure, paralleling the way that native speech competence is acquired (Saffran BVD-523 concentration et al., 1996). This suggests innate factors for the acquisition for both types of auditory information. Through exposure during the first few months and years of life, a quick narrowing to the relevant cultural sounds takes place, both for music (e.g., scale properties) and out speech sounds (e.g., phonemes and prosody) (Kuhl,

2010). Research in musically untrained people indicates that specific neural circuits respond to knowledge of musical rules acquired via exposure in every-day life. Koelsch et al. (2000) showed EEG evidence of sensitivity to violations of musical rules in chord sequences even in musical novices, indicating implicit learning of these rules. Relatedly, Tillmann et al. (2006) found that BOLD signal in frontal and auditory areas was modulated by the harmonic relationship of chords, indicating sensitivity to knowledge of musical structure. In a behavioral cross-cultural study, Wong et al. (2009) showed that the specific rules inherent in Western or Indian music are implicitly learned by people who grow up in either of these cultural environments. These results seem to indicate that passive exposure to music alone is sufficient to alter the neural response to musical sounds to some extent. These changes mostly happen at the later stages of auditory processing, where the complex relationships of harmonies and rhythms are being processed.

5%) compared to embryos heterozygous for either Sema-1a or pbl, a

5%) compared to embryos heterozygous for either Sema-1a or pbl, although premature branching was apparently unaffected ( Figure 5). Similar patterns of genetic interactions were also observed with pbl3, and pbl5 null alleles ( Figure S6). Smad pathway The amino acid Val531, which is changed to aspartate in the pbl5 mutant (V531D), is located within the Pbl DH domain and is known to be required for nucleotide exchange activity in the DH domains of other GEFs ( Liu et al., 1998; Prokopenko et al., 1999). These results suggest

that Sema-1a and Pbl act together in the same signaling pathway to promote motor axon guidance through the regulation of Pbl GEF activity and, since similar genetic interactions are not observed with PlexA, that Pbl functions as an intracellular mediator downstream of Sema-1a rather than PlexA. However, heterozygosity C59 wnt for pblKG07669 significantly enhances the Sema-1a null phenotype ( Figure S6), indicating that additional Pbl guidance functions cooperate with Sema-1a signaling.

Since p190 physically associates with Sema-1a, we next asked whether or not p190 is involved in Sema-1a-mediated motor axon guidance. First, we observed that the p190 RNAi phenotype was suppressed by loss of a single copy of Sema-1a: from 22.1% to 8.2% for premature ISNb branching, and from 36.4% to 21.2% for total ISNb defects ( Figure 5). In contrast, PlexA or PlexB null alleles did not affect the p190 RNAi phenotype. These suppressive genetic interactions between p190 and Sema-1a were also observed using a different p190 RNAi line and the p1902 null allele ( Figure S6). Therefore, p190 functions to antagonize Sema-1a signaling, but not PlexA or PlexB signaling. This is consistent with physical association between p190 and Sema-1a being stronger than with either PlexA or PlexB ( Figure 1B). Taken together, these genetic interaction data suggest that Pbl and p190 exert opposing control over Sema-1a-mediated motor axon. Next, we examined whether pbl and p190 either genetically interact. When a single pbl2 mutant allele was introduced to p190 RNAi knockdown embryos, the premature branching phenotype

was significantly reduced, from 22.1% to 9.4% ( Figure 5). In these embryos, we also observed a significant increase in motor axon defasciculation defects (excluding premature branching phenotypes) at the last ISNb choice point (Figures 3L and 5). To test whether increasing Pbl levels affects premature ISNb branching phenotypes, we overexpressed HA-pbl alone or with coexpression of p190 RNAi in neurons. Increasing Pbl leads to a significant increase in premature branching phenotypes, but does not affect the p190 RNAi phenotype ( Figure S7D). These data suggest that premature ISNb branching is largely controlled by antagonistic functions of p190 and pbl. We find that Sema-1a and Pbl collaborate to induce cell contraction in vitro (Figure 2).