Conditions for minimally tough graphs

Katona, Solt\'esz, and Varga showed that no induced subgraph can be excluded from the class of minimally tough graphs. In this paper, we consider the opposite question, namely which induced subgraphs, if any, must necessarily be present in each minimally $t$-tough graph. Katona and Varga showed that for any rational number $t \in (1/2,1]$, every minimally $t$-tough graph contains a hole. We complement this result by showing that for any rational number $t>1$, every minimally $t$-tough graph must contain either a hole or an induced subgraph isomorphic to the $k$-sun for some integer $k \ge 3$. We also show that for any rational number $t > 1/2$, every minimally $t$-tough graph must contain either an induced $4$-cycle, an induced $5$-cycle, or two independent edges as an induced subgraph

Analyzing the House Fly's Exploratory Behavior with Autoregression Methods

This paper presents a detailed characterization of the trajectory of a single housefly with free range of a square cage. The trajectory of the fly was recorded and transformed into a time series, which was fully analyzed using an autoregressive model, which describes a stationary time series by a linear regression of prior state values with the white noise. The main discovery was that the fly switched styles of motion from a low dimensional regular pattern to a higher dimensional disordered pattern. This discovered exploratory behavior is, irrespective of the presence of food, characterized by anomalous diffusion.Comment: 20 pages, 9 figures, 1 table, full pape

Role of Insulin-Growth Factor II on mitochondrial recovery in a cellular model of Parkinson's Disease

Insulin-growth factor II (IGF-II) has shown antioxidant and neuroprotective effects in some neurodegenerative disorders. ROS causes damage to cellular macromolecules affecting several cellular processes and resulting in cell death. Mitochondrial ROS damage has a critical role in the pathobiology of PD. The objective was to assess the IGF-II role in the recovery of the oxidative damage produced on mitochondrial in a cellular model of PD. SN4741 cell line was treated as follows: MPP+ alone, in presence of IGF-II and/or co-incubated BMS (Ins/IGF-I receptors antagonist) or AB (anti-IGF-II-receptor). To assess the effect of IGF-II in the recovery of MPP+ damage, this treatment was removed after 2 h and replaced during another 2 h by medium, IGF-II or IGF-II + BMS or IGF-II + AB. Cell death was analysed through annexin-V Mitochondrial structure, localization and morphology was studied by western blot/ immunochemistry of Mitofilin (Mtf) and electron microscopy; function by Mitotracker and oxygen consumption rate. IGF-II prevented MPP+ cell death. In morphological/structural studies, MPP+ treated cells showed swollen mitochondria with loss of cristae, and electron-lucent matrix, inducing a mitochondrial number reduction. IGF-II retrieved normal-shaped mitochondria with intact cristae and outer/inner membranes. Moreover, MPP+ incubation significantly reduced the expression levels of Mtf compared to the CO. This expression was found in areas that had a very weak mark, indicating mitochondrial destruction or dysfunction. IGF-II coincubation, recovered the expression of Mtf, remaining associated with healthy mitochondrial function. Additionally, the decrease in OCR levels after MPP+ administration was recovered in presence of IGF-II. The BMS-receptor blockage did not modify the IGF-II responses, and AB limited its effect. In conclusion, IGF-II recovers mitochondrial structure and function due to MPP+ damage. This improvement is carried out through the specific IGF-II receptor.Supported by M.G-F.&L.J.S. Proyectos I+D+I-Programa Operativo-FEDER Andalucía 2014-2020 (UMA18-FEDERJA-004) Junta de Andalucía. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Pion Cloud Contribution to K+ Nucleus Scattering

A careful reanalysis is done of the contribution to $K^{+}$ nucleus scattering from the interaction of the kaon with the virtual pion cloud. The usual approximations made in the evaluation of the related kaon selfenergy are shown to fail badly. We also find new interaction mechanisms which provide appreciable corrections to the kaon selfenergy. Some of these contribute to the imaginary part below pion creation threshold. The inclusion of these new mechanisms in the inelastic part of the optical potential produces a significant improvement in the differential and total $K^{+}$ nuclear cross sections. Uncertainties remain in the dispersive part of the optical potential.Comment: 27 pages, 17 figures (not all of them included, please request them), report UG-DFM-2/9

Large scale grain mantle disruption in the Galactic Center

We present observations of C2H5OH toward molecular clouds in Sgr A, Sgr B2 and associated with thermal and non-thermal features in the Galactic center. C2H5OH emission in Sgr A and Sgr B2 is widespread, but not uniform. C2H5OH emission is much weaker or it is not detected in some molecular clouds in both complexes, in particular those with radial velocities between 70 and 120 km/s. While most of the clouds associated with the thermal features do not show C2H5OH emission, that associated with the Non-Thermal Radio Arc shows emission. The fractional abundance of C2H5OH in most of the clouds with radial velocities between 0 and 70 km/s in Sgr A and Sgr B2 is relatively high, of few 1e-8. The C2H5OH abundance decreases by more than one order of magnitude (aprox. 1e-9) in the clouds associated with the thermal features. The large abundance of C2H5OH in the gas-phase indicates that C2H5OH has formed in grains and released to gas-phase by shocks in the last aprox. 1e5 years.Comment: In press in Astrophysical Journal Letters 7 pages, 1 table, 1 figur

Synthesis and antiprotozoal activity of oligomethylene- and p-phenylene-bis(methylene)-linked bis(+)-huprines

We have synthesized a series of dimers of (+)-(7R,11R)-huprine Y and evaluated their activity against Trypanosoma brucei, Plasmodium falciparum, rat myoblast L6 cells and human acetylcholinesterase (hAChE), and their brain permeability. Most dimers have more potent and selective trypanocidal activity than huprine Y and are brain permeable, but they are devoid of antimalarial activity and remain active against hAChE. Lead optimization will focus on identifying compounds with a more favourable trypanocidal/anticholinesterase activity ratio

Conditions for minimally tough graphs

Katona, Soltész, and Varga showed that no induced subgraph can be excluded from the class of minimally tough graphs. In this paper, we consider the opposite question, namely which induced subgraphs, if any, must necessarily be present in each minimally t-tough graph. Katona and Varga showed that for any rational number t∈(1/2,1], every minimally t-tough graph contains a hole. We complement this result by showing that for any rational number t>1, every minimally t-tough graph must contain either a hole or an induced subgraph isomorphic to the k-sun for some integer k≥3. We also show that for any rational number t>1/2, every minimally t-tough graph must contain either an induced 4-cycle, an induced 5-cycle, or two independent edges as an induced subgraph

Simple gene transfer technique based on I-SceI meganuclease and cytoplasmic injection in IVF bovine embryos

Although transgenic methods in mammals are inefficient, an easy and highly efficient transgenesis systemusing I-SceI meganuclease (intron-encoded endonuclease fromS. cerevisiae)was recently described in Xenopus. The method consisted of injection into fertilized eggs of an I-SceI reaction mixture with a plasmid DNA carrying the transgene, flanked by the meganuclease recognition sites (pIS). In the present study, the effects of I-SceI on gene transfer were tested apparently for the first time in mammals, in particular, in cattle. Various conditions were evaluated, including three concentrations of the plasmid pIS Pax6egfp, carrying I-SceI recognition sites flanking egfp under Pax6 promoter and two injection times (before IVM and after IVF) of pIS CAGegfp, carrying I-SceI sites fanking egfp under CAG promoter. In addition, the quantity of transgenewasmeasured using quantitative polymerase chain reaction, and presence of transgene signals was evaluated using fluorescence in situ hybridization analysis. Transgene expression rateswere higher (P< 0.05) for groups treated after IVF (79.1%, 91/115 and 63.0%, 75/ 119) than before IVM (32.6%, 31/95 and 34.7%, 33/95), with and without I-SceI, respectively. Interestingly, injectionwith pIS plus I-SceI after IVF increased frequency (P<0.05) of nonmosaic transgene-expressing embryos (58.3%, 42/72 vs. 29.7%, 25/84) for pIS plus I-SceI and pIS alone. Based on fluorescence in situ hybridization analysis, injectionwith I-SceI increased (P<0.05) the proportion of embryos with transgene signals in all blastomeres compared with pIS alone (44.0%,11/25 vs. 6.9%, 2/29) for pIS plus I-SceI and pIS alone. In addition, transgene copy number was numerically higher for the group treated with pIS plus I-SceI compared with pIS alone. In conclusion, I-SceI gene transfer increased transgene signals in bovine embryos.Fil: Bevacqua, Romina Jimena. Universidad de Buenos Aires. Facultad de Agronomía. Pabellón de Zootecnica. Laboratorio de Biotecnología Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; ArgentinaFil: Canel, Natalia Gabriela. Universidad de Buenos Aires. Facultad de Agronomía. Pabellón de Zootecnica. Laboratorio de Biotecnología Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; ArgentinaFil: Hiriart, María Inés. Universidad de Buenos Aires. Facultad de Agronomía. Pabellón de Zootecnica. Laboratorio de Biotecnología Animal; ArgentinaFil: Sipowicz, P.. Universidad Nacional de San Martín. Laboratorio de Neuro y Citogenética Molecular; ArgentinaFil: Rozenblum, G. T.. Universidad Maimónides. Area de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; ArgentinaFil: Vitullo, Alfredo Daniel. Universidad Maimónides. Area de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; ArgentinaFil: Radrizzani Helguera, Martin. Universidad Nacional de San Martín. Laboratorio de Neuro y Citogenética Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; ArgentinaFil: Fernández y Martín, Rafael. Universidad de Buenos Aires. Facultad de Agronomía. Pabellón de Zootecnica. Laboratorio de Biotecnología Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; ArgentinaFil: Salamone, Daniel Felipe. Universidad de Buenos Aires. Facultad de Agronomía. Pabellón de Zootecnica. Laboratorio de Biotecnología Animal; Argentin

Fixed Effect Estimation of Large T Panel Data Models

This article reviews recent advances in fixed effect estimation of panel data models for long panels, where the number of time periods is relatively large. We focus on semiparametric models with unobserved individual and time effects, where the distribution of the outcome variable conditional on covariates and unobserved effects is specified parametrically, while the distribution of the unobserved effects is left unrestricted. Compared to existing reviews on long panels (Arellano and Hahn 2007; a section in Arellano and Bonhomme 2011) we discuss models with both individual and time effects, split-panel Jackknife bias corrections, unbalanced panels, distribution and quantile effects, and other extensions. Understanding and correcting the incidental parameter bias caused by the estimation of many fixed effects is our main focus, and the unifying theme is that the order of this bias is given by the simple formula p/n for all models discussed, with p the number of estimated parameters and n the total sample size.Comment: 40 pages, 1 tabl

Trust and contextual engagement with the PEPPER system: The qualitative findings of a clinical feasibility study

Background and aims. PEPPER (Patient Empowerment through Predictive PERsonalised decision support) is an EU-funded research project which aims to improve self-management of type 1 diabetes (T1D). The system comprises an AI insulin bolus recommender, coupled with a safety system. The aim of the qualitative arm of this clinical feasibility study was to examine the context of participants’ interaction with the PEPPER system and identify incidents where bolus recommendations were trusted and accepted. Methods. This was a multicentre (UK and Spain) non-randomised open-labelled 6-week pilot study. Thirteen adults with T1D participated in weekly telephone interviews to explore the context of their interactions and responses to PEPPER. Data was thematically analysed through conceptual frameworks for engagement with healthcare digital behaviour change interventions. Results. Participants reported their key interactions as responding to PEPPER bolus recommendations, inputting carbohydrate values, interpreting continuous glucose monitoring (CGM) values through visualization of personal data and dealing with safety alarms. Two themes were associated with trust and engagement with the system; ‘feeling monitored’ and ‘feeling in control’. The incidents where participants trusted PEPPER also enhanced personal expertise of T1D through insights provided by the safety system such as low glucose basal insulin for pump users. Benefits were balanced against technical challenges of the system, which were used to improve the PEPPER application and enhance user experience. Conclusion. Some participants suggested that even access to PEPPER for a temporary period could positively influence self-management strategies. Contextual interviewing is a valuable tool in mobile application development for diabetes decision support systems