Mechanical detection and pain thresholds: comparability of devices using stepped and ramped stimuli

Quantitative sensory testing is used to assess somatosensory function in humans. The protocol of the German Research Network on Neuropathic Pain (DFNS) provides comprehensive normative values using defined tools; however, some of these may not be feasible in low-resource settings. Objectives: To compare the standard DFNS devices for assessment of mechanosensory function to a low resource tool, the Sorri-Bauru-monofilaments. Methods: Mechanical detection thresholds (MDT), pain thresholds (MPT), and suprathreshold pinprick ratings (pain sensitivity: MPS) were measured over cheek, hand dorsum, and fingertip in 13 healthy subjects (7 female, aged 21-44 years). Mechanical detection threshold was assessed with DFNS standard glass monofilaments (0.25-512 mN, 0.5 mm tip) and nylon monofilaments (Sorri-Bauru; 0.5-3000 mN). MPT was assessed with DFNS standard cylindrical probes (8-512 mN, 0.25 mm tip), Sorri-Bauru monofilaments, and with ramped stimuli using an electronic von Frey aesthesiometer (10 mN/s or 100 mN/s, 0.20 mm tip). MPS was measured in response to stepped and ramped pinpricks (128 and 256 mN). Results: Mechanical detection thresholds were the same for DFNS and Sorri-Bauru monofilaments. For MPT, Sorri-Bauru filaments yielded lower values than PinPricks over face but not hand. Pain thresholds were higher at all test sites for ramped than stepped pinpricks (P < 0.01). Suprathreshold ratings were lower for ramped than stepped pinpricks (P < 0.05). Conclusion: Sorri-Bauru filaments are acceptable substitutes for DFNS standards in estimating tactile sensitivity, but are not consistent with standard probes for pinprick sensitivity because of their nonstandardized tips. Ramped stimuli overestimated MPT and underestimated MPS due to reaction time artefacts and therefore need their own normative values

Dynamical Mean-Field Theory

The dynamical mean-field theory (DMFT) is a widely applicable approximation scheme for the investigation of correlated quantum many-particle systems on a lattice, e.g., electrons in solids and cold atoms in optical lattices. In particular, the combination of the DMFT with conventional methods for the calculation of electronic band structures has led to a powerful numerical approach which allows one to explore the properties of correlated materials. In this introductory article we discuss the foundations of the DMFT, derive the underlying self-consistency equations, and present several applications which have provided important insights into the properties of correlated matter.Comment: Chapter in "Theoretical Methods for Strongly Correlated Systems", edited by A. Avella and F. Mancini, Springer (2011), 31 pages, 5 figure

Impact Factor: outdated artefact or stepping-stone to journal certification?

A review of Garfield's journal impact factor and its specific implementation as the Thomson Reuters Impact Factor reveals several weaknesses in this commonly-used indicator of journal standing. Key limitations include the mismatch between citing and cited documents, the deceptive display of three decimals that belies the real precision, and the absence of confidence intervals. These are minor issues that are easily amended and should be corrected, but more substantive improvements are needed. There are indications that the scientific community seeks and needs better certification of journal procedures to improve the quality of published science. Comprehensive certification of editorial and review procedures could help ensure adequate procedures to detect duplicate and fraudulent submissions.Comment: 25 pages, 12 figures, 6 table

The Hubbard model within the equations of motion approach

The Hubbard model has a special role in Condensed Matter Theory as it is considered as the simplest Hamiltonian model one can write in order to describe anomalous physical properties of some class of real materials. Unfortunately, this model is not exactly solved except for some limits and therefore one should resort to analytical methods, like the Equations of Motion Approach, or to numerical techniques in order to attain a description of its relevant features in the whole range of physical parameters (interaction, filling and temperature). In this manuscript, the Composite Operator Method, which exploits the above mentioned analytical technique, is presented and systematically applied in order to get information about the behavior of all relevant properties of the model (local, thermodynamic, single- and two- particle ones) in comparison with many other analytical techniques, the above cited known limits and numerical simulations. Within this approach, the Hubbard model is shown to be also capable to describe some anomalous behaviors of the cuprate superconductors.Comment: 232 pages, more than 300 figures, more than 500 reference

Study of the reaction e^{+}e^{-} -->J/psi\pi^{+}\pi^{-} via initial-state radiation at BaBar

We study the process $e^+e^-\to J/\psi\pi^{+}\pi^{-}$ with initial-state-radiation events produced at the PEP-II asymmetric-energy collider. The data were recorded with the BaBar detector at center-of-mass energies 10.58 and 10.54 GeV, and correspond to an integrated luminosity of 454 $\mathrm{fb^{-1}}$. We investigate the $J/\psi \pi^{+}\pi^{-}$ mass distribution in the region from 3.5 to 5.5 $\mathrm{GeV/c^{2}}$. Below 3.7 $\mathrm{GeV/c^{2}}$ the $\psi(2S)$ signal dominates, and above 4 $\mathrm{GeV/c^{2}}$ there is a significant peak due to the Y(4260). A fit to the data in the range 3.74 -- 5.50 $\mathrm{GeV/c^{2}}$ yields a mass value $4244 \pm 5$ (stat) $\pm 4$ (syst)$\mathrm{MeV/c^{2}}$ and a width value $114 ^{+16}_{-15}$ (stat)$\pm 7$(syst)$\mathrm{MeV}$ for this state. We do not confirm the report from the Belle collaboration of a broad structure at 4.01 $\mathrm{GeV/c^{2}}$. In addition, we investigate the $\pi^{+}\pi^{-}$ system which results from Y(4260) decay

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Growth landscape formed by perception and import of glucose in yeast

An important challenge in systems biology is to quantitatively describe microbial growth using a few measurable parameters that capture the essence of this complex phenomenon. Two key events at the cell membrane—extracellular glucose sensing and uptake—initiate the budding yeast’s growth on glucose. However, conventional growth models focus almost exclusively on glucose uptake. Here we present results from growth-rate experiments that cannot be explained by focusing on glucose uptake alone. By imposing a glucose uptake rate independent of the sensed extracellular glucose level, we show that despite increasing both the sensed glucose concentration and uptake rate, the cell’s growth rate can decrease or even approach zero. We resolve this puzzle by showing that the interaction between glucose perception and import, not their individual actions, determines the central features of growth, and characterize this interaction using a quantitative model. Disrupting this interaction by knocking out two key glucose sensors significantly changes the cell’s growth rate, yet uptake rates are unchanged. This is due to a decrease in burden that glucose perception places on the cells. Our work shows that glucose perception and import are separate and pivotal modules of yeast growth, the interaction of which can be precisely tuned and measured.National Institutes of Health (U.S.). Pioneer AwardNatural Sciences and Engineering Research Council of Canada (NSERC). Graduate Fellowshi

Evidence for biological roots in the transgenerational transmission of intimate partner violence

Intimate partner violence is a ubiquitous and devastating phenomenon for which effective interventions and a clear etiological understanding are still lacking. A major risk factor for violence perpetration is childhood exposure to violence, prompting the proposal that social learning is a major contributor to the transgenerational transmission of violence. Using an animal model devoid of human cultural factors, we showed that male rats became highly aggressive against their female partners as adults after exposure to non-social stressful experiences in their youth. Their offspring also showed increased aggression toward females in the absence of postnatal father–offspring interaction or any other exposure to violence. Both the females that cohabited with the stressed males and those that cohabited with their male offspring showed behavioral (including anxiety- and depression-like behaviors), physiological (decreased body weight and basal corticosterone levels) and neurobiological symptoms (increased activity in dorsal raphe serotonergic neurons in response to an unfamiliar male) resembling the alterations described in abused and depressed women. With the caution required when translating animal work to humans, our findings extend current psychosocial explanations of the transgenerational transmission of intimate partner violence by strongly suggesting an important role for biological factors