Anticipating Daily Intention using On-Wrist Motion Triggered Sensing

Anticipating human intention by observing one's actions has many applications. For instance, picking up a cellphone, then a charger (actions) implies that one wants to charge the cellphone (intention). By anticipating the intention, an intelligent system can guide the user to the closest power outlet. We propose an on-wrist motion triggered sensing system for anticipating daily intentions, where the on-wrist sensors help us to persistently observe one's actions. The core of the system is a novel Recurrent Neural Network (RNN) and Policy Network (PN), where the RNN encodes visual and motion observation to anticipate intention, and the PN parsimoniously triggers the process of visual observation to reduce computation requirement. We jointly trained the whole network using policy gradient and cross-entropy loss. To evaluate, we collect the first daily "intention" dataset consisting of 2379 videos with 34 intentions and 164 unique action sequences. Our method achieves 92.68%, 90.85%, 97.56% accuracy on three users while processing only 29% of the visual observation on average

Inhibition of the Gab2/PI3K/mTOR signaling ameliorates myeloid malignancy caused by Ptpn11 (Shp2) gain-of-function mutations

Activating mutations, such as E76K and D61Y, in PTPN11 (SHP2), a protein tyrosine phosphatase implicated in multiple cell signaling processes, are associated with 35% of patients with juvenile myelomonocytic leukemia (JMML), an aggressive childhood myeloproliferative neoplasm (MPN). Here we show that the interaction between leukemia-associated mutant Shp2 and Gab2, a scaffolding protein important for cytokine-induced PI3K/Akt signaling, was enhanced, and that the mTOR pathway was elevated in Ptpn11E76K/+ leukemic cells. Importantly, MPN induced by the Ptpn11E76K/+ mutation was markedly attenuated in Ptpn11E76K/+/Gab2-/- double mutant mice-overproduction of myeloid cells was alleviated, splenomegaly was diminished and myeloid cell infiltration in nonhematopoietic organs was decreased in these double mutants. Excessive myeloid differentiation of stem cells was also normalized by depletion of Gab2. Acute leukemia progression of MPN was reduced in the double mutant mice and, as such, their survival was much prolonged. Furthermore, treatment of Ptpn11E76K/+ mice with Rapamycin, a specific and potent mTOR inhibitor, mitigated MPN phenotypes. Collectively, this study reveals an important role of the Gab2/PI3K/mTOR pathway in mediating the pathogenic signaling of the PTPN11 gain-of-function mutations and a therapeutic potential of Rapamycin for PTPN11 mutation-associated JMML

An assessment of pulse transit time for detecting heavy blood loss during surgical operation

Copyright @ Wang et al.; Licensee Bentham Open. This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.The main contribution of this paper is the use of non-invasive measurements such as electrocardiogram (ECG) and photoplethysmographic (PPG) pulse oximetry waveforms to develop a new physiological signal analysis technique for detecting blood loss during surgical operation. Urological surgery cases were considered as the control group due to its generality, and cardiac surgery as experimental group since it involves blood loss and water supply. Results show that the control group has the tendency of a reduction of the pulse transient time (PTT), and this indicates an increment in the blood flow velocity changes from slow to fast. While for the experimental group, the PTT indicates high values during blood loss, and low values during water supply. Statistical analysis shows considerable differences (i.e., P <0.05) between both groups leading to the conclusion that PTT could be a good indicator for monitoring patients' blood loss during a surgical operation.The National Science Council (NSC) of Taiwan and the Centre for Dynamical Biomarkers and Translational Medicine, National Central University, Taiwan

Induced magnetism in transition metal intercalated graphitic systems

We investigate the structure, chemical bonding, electronic properties, and magnetic behavior of a three-dimensional graphitic network in aba and aaa stacking with intercalated transition metal atoms (Mn, Fe, Co, Ni, and Cu). Using density functional theory, we find induced spin-polarization of the C atoms both when the graphene sheets are aba stacked (forming graphite) and aaa stacked (resembling bi-layer graphene). The magnetic moment induced by Mn, Fe, and Co turns out to vary from 1.38 {\mu}B to 4.10 {\mu}B, whereas intercalation of Ni and Cu does not lead to a magnetic state. The selective induction of spin-polarization can be utilized in spintronic and nanoelectronic applications.Comment: 13 pages, 3 figures, 1 tabl

Unfolding Collapsed Polyelectrolytes in Alternating-Current Electric Fields

We investigate the unfolding of single polyelectrolyte (PE) chains collapsed by trivalent salt under the action of alternating-current (AC) electric fields through computer simulations and theoretical scaling. The results show that a collapsed chain can be unfolded by an AC field when the field strength exceeds the direct-current (DC) threshold and the frequency is below a critical value, corresponding to the inverse charge relaxation/dissociation time of condensed trivalent counterions at the interface of the collapsed electrolyte. This relaxation time is also shown to be identical to the DC chain fluctuation time, suggesting that the dissociation of condensed polyvalent counterion on the collapsed PE interface controls the polyelectrolyte dipole formation and unfolding dynamics under an AC electric field.Comment: 18 pages, 5 figures, submitte

Small Conductance Calcium-Activated Potassium Current is Activated During Hypokalemia and Masks Short Term Cardiac Memory Induced by Ventricular Pacing.

Background: Hypokalemia increases the vulnerability to ventricular fibrillation (VF). We hypothesize that the apamin-sensitive small conductance calcium-activated potassium current (IKAS) is activated during hypokalemia and that IKAS blockade is proarrhythmic. Methods and Results: Optical mapping was performed in 23 Langendorff perfused rabbit ventricles with atrioventricular block and either right ventricular (RV) or left ventricular (LV) pacing during normokalemia or hypokalemia. Apamin prolonged the action potential duration (APD) measured to 80% repolarization (APD80) by 26 ms [95% confidence interval, CI, 14–37] during normokalemia and by 54 ms [CI, 40 to 68] during hypokalemia (P=0.01) at 1000 ms pacing cycle length (PCL). In hypokalemic ventricles, apamin increased the maximal slope of APD restitution, the PCL threshold of APD alternans, the PCL for wavebreak induction and the area of spatially discordant APD alternans. Apamin significantly facilitated the induction of sustained VF (from 3/9 hearts to 9/9 hearts, P=0.009). Short term cardiac memory was assessed by the slope of APD80 versus activation time. The slope increased from 0.01 [CI, −0.09 to 0.12] at baseline to 0.34 [CI, 0.23 to 0.44] after apamin (P<0.001) during RV pacing, and from 0.07 [CI, −0.05 to 0.20] to 0.54 [CI, 0.06 to 1.03] after apamin infusion (P=0.045) during LV pacing. Patch-clamp studies confirmed increased IKASin isolated rabbit ventricular myocytes during hypokalemia (P=0.038). Conclusions: Hypokalemia activates IKAS to shorten APD and maintain repolarization reserve at late activation sites during ventricular pacing. IKAS blockade prominently lengthens the APD at late activation sites and facilitates VF induction

Role of Apamin-Sensitive Calcium-Activated Small-Conductance Potassium Currents on the Mechanisms of Ventricular Fibrillation in Pacing-Induced Failing Rabbit Hearts

BACKGROUND: Ventricular fibrillation (VF) during heart failure is characterized by stable reentrant spiral waves (rotors). Apamin-sensitive small-conductance calcium-activated potassium currents (IKAS) are heterogeneously upregulated in failing hearts. We hypothesized that IKAS influences the location and stability of rotors during VF. METHODS AND RESULTS: Optical mapping was performed on 9 rabbit hearts with pacing-induced heart failure. The epicardial right ventricular and left ventricular surfaces were simultaneously mapped in a Langendorff preparation. At baseline and after apamin (100 nmol/L) infusion, the action potential duration (APD80) was determined, and VF was induced. Areas with a >50% increase in the maximum action potential duration (ΔAPD) after apamin infusion were considered to have a high IKAS distribution. At baseline, the distribution density of phase singularities during VF in high IKAS distribution areas was higher than in other areas (0.0035±0.0011 versus 0.0014±0.0010 phase singularities/pixel; P=0.004). In addition, high dominant frequencies also colocalized to high IKAS distribution areas (26.0 versus 17.9 Hz; P=0.003). These correlations were eliminated during VF after apamin infusion, as the number of phase singularities (17.2 versus 11.0; P=0.009) and dominant frequencies (22.1 versus 16.2 Hz; P=0.022) were all significantly decreased. In addition, reentrant spiral waves became unstable after apamin infusion, and the duration of VF decreased. CONCLUSIONS: The IKAS current influences the mechanism of VF in failing hearts as phase singularities, high dominant frequencies, and reentrant spiral waves all correlated to areas of high IKAS. Apamin eliminated this relationship and reduced VF vulnerability