A Tale of Two Animats: What does it take to have goals?

What does it take for a system, biological or not, to have goals? Here, this question is approached in the context of in silico artificial evolution. By examining the informational and causal properties of artificial organisms ('animats') controlled by small, adaptive neural networks (Markov Brains), this essay discusses necessary requirements for intrinsic information, autonomy, and meaning. The focus lies on comparing two types of Markov Brains that evolved in the same simple environment: one with purely feedforward connections between its elements, the other with an integrated set of elements that causally constrain each other. While both types of brains 'process' information about their environment and are equally fit, only the integrated one forms a causally autonomous entity above a background of external influences. This suggests that to assess whether goals are meaningful for a system itself, it is important to understand what the system is, rather than what it does.Comment: This article is a contribution to the FQXi 2016-2017 essay contest "Wandering Towards a Goal

Dwarf Novae in the Shortest Orbital Period Regime: I. A New Short Period Dwarf Nova, OT J055717+683226

We report the observation of a new dwarf nova, OT J055717+683226, during its first-ever recorded superoutburst in December 2006. Our observation shows that this object is an SU UMa-type dwarf nova having a very short superhump period of 76.67+/- 0.03 min (0.05324+/-0.00002 d). The next superoutburst was observed in March 2008. The recurrence time of superoutbursts (supercycle) is, hence, estimated to be ~480 d. The supercycle is much shorter than those of WZ Sge-type dwarf novae having supercycles of >~ 10 yr, which are a major population of dwarf novae in the shortest orbital period regime (<~85 min). Using a hierarchical cluster analysis, we identified seven groups of dwarf novae in the shortest orbital period regime. We identified a small group of objects that have short supercycles, small outburst amplitudes, and large superhump period excesses, compared with those of WZ Sge stars. OT J055717+683226 probably belongs to this group.Comment: 14 pages, 11 figures, accepted for publication in PAS

Inhomogeneous superconductivity in organic conductors: role of disorder and magnetic field

Several experimental studies have shown the presence of spatially inhomogeneous phase coexistence of superconducting and non superconducting domains in low dimensional organic superconductors. The superconducting properties of these systems are found to be strongly dependent on the amount of disorder introduced in the sample regardless of its origin. The suppression of the superconducting transition temperature $T_c$ shows clear discrepancy with the result expected from the Abrikosov-Gor'kov law giving the behavior of $T_c$ with impurities. Based on the time dependent Ginzburg-Landau theory, we derive a model to account for the striking feature of $T_c$ in organic superconductors for different types of disorder by considering the segregated texture of the system. We show that the calculated $T_c$ quantitatively agrees with experiments. We also focus on the role of superconducting fluctuations on the upper critical fields $H_{c2}$ of layered superconductors showing slab structure where superconducting domains are sandwiched by non-superconducting regions. We found that $H_{c2}$ may be strongly enhanced by such fluctuations.Comment: to appear in Journal of Physics: Condensed Matte

Impurity Effect on Superconducting Properties in Molecular Substituted Organic Superconductor κ\kappa-(ET)2_2Cu(NCS)2_2

We report an impurity effect in the organic superconductor $\kappa$-(ET)$_2$Cu(NCS)$_2$ by substitution of the ET molecule with an analogue, bis(methyleneditio)tetrathiafulvalene (MT). The superconducting transition temperature decreases with increasing substitution. The in-plane magnetic penetration depth is enhanced with substitution, which is quantitatively attributed to the decrease in the in-plane mean free path. The enhancement of the penetration depth can also explain the reduction of the effective pinning in terms of the condensation energy.Comment: 4 pages, submitted to J. Phys. Soc. Jp

Complexity of multi-dimensional spontaneous EEG decreases during propofol induced general anaesthesia

Emerging neural theories of consciousness suggest a correlation between a specific type of neural dynamical complexity and the level of consciousness: When awake and aware, causal interactions between brain regions are both integrated (all regions are to a certain extent connected) and differentiated (there is inhomogeneity and variety in the interactions). In support of this, recent work by Casali et al (2013) has shown that Lempel-Ziv complexity correlates strongly with conscious level, when computed on the EEG response to transcranial magnetic stimulation. Here we investigated complexity of spontaneous high-density EEG data during propofol-induced general anaesthesia. We consider three distinct measures: (i) Lempel-Ziv complexity, which is derived from how compressible the data are; (ii) amplitude coalition entropy, which measures the variability in the constitution of the set of active channels; and (iii) the novel synchrony coalition entropy (SCE), which measures the variability in the constitution of the set of synchronous channels. After some simulations on Kuramoto oscillator models which demonstrate that these measures capture distinct ‘flavours’ of complexity, we show that there is a robustly measurable decrease in the complexity of spontaneous EEG during general anaesthesia

Dynamical complexity in the C.elegans neural network

We model the neuronal circuit of the C.elegans soil worm in terms of a Hindmarsh-Rose system of ordinary differential equa- tions, dividing its circuit into six communities which are determined via the Walktrap and Louvain methods. Using the numerical solution of these equations, we analyze important measures of dynamical com- plexity, namely synchronicity, the largest Lyapunov exponent, and the ?AR auto-regressive integrated information theory measure. We show that ?AR provides a useful measure of the information contained in the C.elegans brain dynamic network. Our analysis reveals that the C.elegans brain dynamic network generates more information than the sum of its constituent parts, and that attains higher levels of integrated information for couplings for which either all its communities are highly synchronized, or there is a mixed state of highly synchronized and de- synchronized communities

Nine weeks of supplementation with a multi-nutrient product augments gains in lean mass, strength, and muscular performance in resistance trained men

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to compare the effects of supplementation with Gaspari Nutrition's SOmaxP Maximum Performance™ (SOmaxP) versus a comparator product (CP) containing an equal amount of creatine (4 g), carbohydrate (39 g maltodextrin), and protein (7 g whey protein hydrolysate) on muscular strength, muscular endurance, and body composition during nine weeks of intense resistance training.</p> <p>Methods</p> <p>Using a prospective, randomized, double-blind design, 20 healthy men (mean ± SD age, height, weight, % body fat: 22.9 ± 2.6 y, 178.4 ± 5.7 cm, 80.5 ± 6.6 kg, 16.6 ± 4.0%) were matched for age, body weight, resistance training history, bench press strength, bench press endurance, and percent body fat and then randomly assigned via the ABBA procedure to ingest 1/2 scoop (dissolved in 15 oz water) of SOmaxP or CP prior to, and another 1/2 scoop (dissolved in 15 oz water) during resistance exercise. Body composition (DEXA), muscular performance (1-RM bench press and repetitions to failure [RTF: 3 sets × baseline body weight, 60-sec rest between sets]), and clinical blood chemistries were measured at baseline and after nine weeks of supplementation and training. Subjects were required to maintain their normal dietary habits and follow a specific, progressive overload resistance training program (4-days/wk, upper body/lower body split) during the study. An intent-to-treat approach was used and data were analyzed via ANCOVA using baseline values as the covariate. Statistical significance was set <it>a priori </it>at p ≤ 0.05.</p> <p>Results</p> <p>When adjusted for initial differences, significant between group post-test means were noted in: 1-RM bench press (SOmaxP: 133.3 ± 1.3 kg [19.8% increase] vs. CP: 128.5 ± 1.3 kg [15.3% increase]; p < 0.019); lean mass (SOmaxP: 64.1 ± 0.4 kg [2.4% increase] vs. 62.8 ± 0.4 kg [0.27% increase], p < 0.049); RTF (SOmaxP: 33.3 ± 1.1 reps [44.8% increase] vs. 27.8 ± 1.1 reps [20.9% increase], p < 0.004); and fat mass (SOmaxP: 12.06 ± 0.53 kg [9.8% decrease] vs. 13.90 ± 0.53 kg [4.1% increase], p < 0.024). No statistically significant differences in vital signs (heart rate, systolic and diastolic blood pressures) or clinical blood chemistries were noted.</p> <p>Conclusions</p> <p>These data indicate that compared to CP, SOmaxP administration augments and increases gains in lean mass, bench press strength, and muscular performance during nine weeks of intense resistance training. Studies designed to confirm these results and clarify the molecular mechanisms by which SOmaxP exerts the observed salutary effects have begun. Both SOmaxP and the CP were well-tolerated, and no supplement safety issues were identified.</p

γ-Secretase inhibitor enhances antitumour effect of radiation in Notch-expressing lung cancer

BACKGROUND: Notch receptor has an important role in both development and cancer. We previously reported that inhibition of the Notch3 by γ-secretase inhibitor (GSI) induces apoptosis and suppresses tumour proliferation in non-small-cell lung cancer. Although radiation is reported to induce Notch activation, little is known about the relationship between radiation and Notch pathway. METHODS: We examined the effect of combining GSI and radiation at different dosing in three Notch expressing lung cancer cell lines. The cytotoxic effect of GSI and radiation was evaluated using MTT assay and clonogenic assay in vitro and xenograft models. Expressions of Notch pathway, mitogen-activated protein kinase (MAPK) pathway and Bcl-2 family proteins were investigated using western blot analysis. RESULTS: We discovered that the antitumour effect of combining GSI and radiation was dependent on treatment schedule. γ-Secretase inhibitor administration after radiation had the greatest growth inhibition of lung cancer in vitro and in vivo. We showed that the combination induced apoptosis of lung cancer cell lines through the regulation of MAPK and Bcl-2 family proteins. Furthermore, activation of Notch after radiation was ameliorated by GSI administration, suggesting that treatment with GSI prevents Notch-induced radiation resistance. CONCLUSION: Notch has an important role in lung cancer. Treatment with GSI after radiation can significantly enhance radiation-mediated tumour cytotoxicity

Angiotensin-converting enzyme gene and retinal arteriolar narrowing: The Funagata Study

The purpose of this study is to determine whether the angiotensin-converting enzyme (ACE) gene polymorphism is associated with retinal arteriolar narrowing, a subclinical marker of chronic hypertension. The Funagata Study examined a population-based sample of Japanese aged 35+ years; 368 participants had both retinal vessel diameter measurements and ACE insertion/deletion (ACE I/D) polymorphism analyses performed. Assessment of retinal vessel diameter and retinal vessel wall signs followed the protocols used in the Blue Mountains Eye Study. ACE gene polymorphisms D/D, I/D and I/I were present in 34 (9.2%), 170 (46.2%) and 164 (44.5%) participants, respectively, distributed in Hardy–Weinberg equilibrium. After multivariable adjustment, retinal arteriolar diameter was significantly narrower in subjects with the D/D genotype compared to subjects with I/D and I/I genotypes (mean difference −6.49 μm, 95% confidence interval (CI): −12.86 μm, −0.11 μm). Our study suggests that the ACE I/D polymorphism may be associated with subclinical structural arteriolar changes related to chronic hypertension