Linear Self-Motion Cues Support the Spatial Distribution and Stability of Hippocampal Place Cells

The vestibular system provides a crucial component of place-cell and head-direction cell activity [1-7]. Otolith signals are necessary for head-direction signal stability and associated behavior [8, 9], and the head-direction signal's contribution to parahippocampal spatial representations [10-14] suggests that place cells may also require otolithic information. Here, we demonstrate that self-movement information from the otolith organs is necessary for the development of stable place fields within and across sessions. Place cells in otoconia-deficient tilted mice showed reduced spatial coherence and formed place fields that were located closer to environmental boundaries, relative to those of control mice. These differences reveal an important otolithic contribution to place-cell functioning and provide insight into the cognitive deficits associated with otolith dysfunction

Report of the panel on earth structure and dynamics, section 6

The panel identified problems related to the dynamics of the core and mantle that should be addressed by NASA programs. They include investigating the geodynamo based on observations of the Earth's magnetic field, determining the rheology of the mantle from geodetic observations of post-glacial vertical motions and changes in the gravity field, and determining the coupling between plate motions and mantle flow from geodetic observations of plate deformation. Also emphasized is the importance of support for interdisciplinary research to combine various data sets with models which couple rheology, structure and dynamics

Record-breaking earthquake intervals in a global catalogue and an aftershock sequence

For the purposes of this study, an interval is the elapsed time between two earthquakes in a designated region; the minimum magnitude for the earthquakes is prescribed. A record-breaking interval is one that is longer (or shorter) than preceding intervals; a starting time must be specified. We consider global earthquakes with magnitudes greater than 5.5 and show that the record-breaking intervals are well estimated by a Poissonian (random) theory. We also consider the aftershocks of the 2004 Parkfield earthquake and show that the record-breaking intervals are approximated by very different statistics. In both cases, we calculate the number of record-breaking intervals (<i>n</i><sub>rb</sub>) and the record-breaking interval durations Δ<i>t</i><sub>rb</sub> as a function of "natural time", the number of elapsed events. We also calculate the ratio of record-breaking long intervals to record-breaking short intervals as a function of time, <i>r(t)</i>, which is suggested to be sensitive to trends in noisy time series data. Our data indicate a possible precursory signal to large earthquakes that is consistent with accelerated moment release (AMR) theory

Autonomous Light Management in Flexible Photoelectrochromic Films Integrating High Performance Silicon Solar Microcells

Commercial smart window technologies for dynamic light and heat management in building and automotive environments traditionally rely on electrochromic (EC) materials powered by an external source. This design complicates building-scale installation requirements and substantially increases costs for applications in retrofit construction. Self-powered photoelectrochromic (PEC) windows are an intuitive alternative wherein a photovoltaic (PV) material is used to power the electrochromic device, which modulates the transmission of the incident solar flux. The PV component in this application must be sufficiently transparent and produce enough power to efficiently modulate the EC device transmission. Here, we propose Si solar microcells (μ-cells) that are i) small enough to be visually transparent to the eye, and ii) thin enough to enable flexible PEC devices. Visual transparency is achieved when Si μ-cells are arranged in high pitch (i.e. low-integration density) form factors while maintaining the advantages of a single-crystalline PV material (i.e., long lifetime and high performance). Additionally, the thin dimensions of these Si μ-cells enable fabrication on flexible substrates to realize these flexible PEC devices. The current work demonstrates this concept using WO₃ as the EC material and V₂O₅ as the ion storage layer, where each component is fabricated via sol-gel methods that afford improved prospects for scalability and tunability in comparison to thermal evaporation methods. The EC devices display fast switching times, as low as 8 seconds, with a modulation in transmission as high as 33%. Integration with two Si μ-cells in series (affording a 1.12 V output) demonstrates an integrated PEC module design with switching times of less than 3 minutes, and a modulation in transmission of 32% with an unprecedented EC:PV areal ratio

Hypertension treatment intensification among stroke survivors with uncontrolled blood pressure

Objective The study objective was to evaluate a pharmacist hypertension care management program within the patient-centered medical home. Methods This was a retrospective case-control study. Cases included all patients with hypertension who were referred to the care management program, and controls included patients with hypertension who were not referred to the program during the same 1-year period. Each case was matched to a maximum of 3 controls on the basis of primary care physician, age ±5 years, gender, diagnoses of diabetes and kidney disease, baseline systolic blood pressure ±10 mm Hg, and number of unique antihypertensive medications. Pharmacists provided a hypertension care management program under an approved scope of practice that allowed pharmacists to meet individually with patients, adjust medications, and provide patient education. Primary outcomes were systolic blood pressure and diastolic blood pressure at 6 and 12 months. Multivariate regression models compared each blood pressure end point between cases and controls adjusting for age, comorbidities, baseline blood pressure, and baseline number of blood pressure medications. Results A total of 573 patients were referred to the hypertension program; 86% (465/543) had at least 1 matched control and were included as cases in the analyses; 3:1 matching was achieved in 90% (418/465) of cases. At baseline, cases and controls did not differ with respect to age, gender, race, or comorbidity; baseline blood pressure was higher (139.9/80.0 mm Hg vs 136.7/78.2 mm Hg, P ≤ .0002) in the cases compared with controls. Multivariate regression modeling identified significantly lower systolic blood pressure for the cases compared with controls at both 6 and 12 months (6-month risk ratio [RR], 9.7; 95% confidence interval [CI], 2.7-35.3; 12-month RR, 20.3; 95% CI, 4.1-99.2; P < .01 for both comparisons). Diastolic blood pressure was significantly lower at 12 months (RR, 2.9; 95% CI, 1.2-7.1; P < .01) but not at 6 months (RR, 1.0; 95% CI, 0.31-3.4; P = .9) for the cases compared with controls. Conclusions Patients who were referred to the pharmacist hypertension care management program had a significant improvement in most blood pressure outcomes. This program may be an effective method of improving blood pressure control among patients in a medical home model of primary care

Effects of Human Apolipoprotein E3 and E4 Genotypes on Cardiometabolic Disease Risk

Apolipoprotein (apo) E isoforms have specific effects on the etiology of cardiovascular disease (CVD), but data is limited on the effects of these genotypes for the risk of type 2 diabetes mellitus (T2DM) and related cardiometabolic alterations. The purpose of this study was to determine the effects of human apoE3 and E4 genotypes on risk factors for T2DM and cardiac metabolism. Cardiac tissue from human apoE3 (n=8) and E4 (n=8) knock-in (KI) mice were compared to lean (n=11) and diet-induced obese (n=12) B6D2F1 mice to characterize the cardiac metabolic activity of AMPK, as well as for lipid and glycogen levels. Plasma was analyzed for lipid and lipoprotein concentrations, as well as glucose, insulin and HOMA-IR. An ANOVA was used to identify differences between groups. Statistical significance was set at a P\u3c0.05. ApoE3 and E4 mice displayed mild insulin resistance (Table 1) despite for having a body mass similar to the lean mice. In addition, apoE3 mice had a 1.5 fold greater HOMA-IR than apoE4 mice. Interestingly, apoE3 and E4 mice had significantly lower TC, Tg and HDL-C than both lean and obese mice. In apoE3 mice, nonHDL-C was significantly lower than both the lean and obese mice and the apoE4 mice. In apoE3 mice, cardiac cholesterol was greater than both lean and obese controls and apoE4 mice. In contrast, apoE4 mice had 2.5 and 2.9 fold greater cardiac triglyceride levels than the lean and obese mice, respectively. In the absence of an obesogenic diet, apoE3 and E4 mice displayed an insulin resistant metabolic state combined with altered lipid and lipoprotein metabolism that paralleled an increase in cardiac lipid deposition. These alterations in cardiac metabolism may contribute to the increased risk of CVD observed in apoE3 and E4 genotypes

Dressed Spin of Polarized 3He in a Cell

We report a measurement of the modification of the effective precession frequency of polarized 3He atoms in response to a dressing field in a room temperature cell. The 3He atoms were polarized using the metastability spin-exchange method. An oscillating dressing field is then applied perpendicular to the constant magnetic field. Modification of the 3He effective precession frequency was observed over a broad range of the amplitude and frequency of the dressing field. The observed effects are compared with calculations based on quantum optics formalism.Comment: 10 pages, 4 figure

Urine THC Metabolite Levels Correlate with Striatal D2/D3 Receptor Availability

poster abstractRationale: Although the incidence of cannabis abuse/dependence in Americans is rising, the neurobiology of cannabis addiction is not well understood. Recent imaging studies have demonstrated deficits in striatal D2/D3 receptor availability in several substance-dependent populations. However, this has not been studied in chronic cannabis users. Objective: The purpose of this study was to compare striatal D2/D3 receptor availability between currently using chronic cannabis users and healthy controls. Methods: Eighteen right-handed males, age 18-35 were studied. Ten subjects were chronic cannabis users; eight were demographically matched controls. Subject eligibility was determined during a screening interview, which included SCID-I and SCID-II assessments, self-report of past substance use, and drug toxicology screening. Subjects underwent a [11C]raclopride (RAC) PET scan; striatal RAC binding potential (BPND) was calculated on a voxel-wise basis with the multilinear reference tissue method. Prior to scanning, urine samples were obtained from cannabis users for quantification of urine Δ-9-tetrahydrocannabinol (THC) and THC metabolites (11-nor-Δ-9-THC-9-carboxylic acid; THC-COOH). Statistical analyses were conducted at voxel-wise level within the striatum. Two-sample t-tests were used to test for differences in BPND between groups. For cannabis subjects, multiple regression analyses were used to test for correlations between striatal BPND and urine THC/THC metabolite levels. Results: There were no differences in BPND between cannabis smokers and healthy controls. Smokers – regardless of substance – had 10% lower D2/D3 availability than non-smokers. Voxel-wise analyses revealed that striatal RAC BPND values were associated with urine levels of cannabis metabolites. Conclusions: Cannabis and cannabis metabolites in urine, markers of recent cannabis consumption, are negatively correlated with striatal RAC BPND. This provides the first evidence that degree of cannabis use is related to changes in the central DA system. Low BPND in both cannabis and cigarette users may indicate a deficiency in D2/D3 receptors as a function of chronic exposure to either or both substances. Alternatively, endogenous dopamine levels may be higher in smokers as a result of MAO inhibition from beta-carbolines in the inhaled smoke. Additional studies are needed to understand the complex relationships between chronic cannabis use and the dopamine system

Tidal friction in close-in satellites and exoplanets. The Darwin theory re-visited

This report is a review of Darwin's classical theory of bodily tides in which we present the analytical expressions for the orbital and rotational evolution of the bodies and for the energy dissipation rates due to their tidal interaction. General formulas are given which do not depend on any assumption linking the tidal lags to the frequencies of the corresponding tidal waves (except that equal frequency harmonics are assumed to span equal lags). Emphasis is given to the cases of companions having reached one of the two possible final states: (1) the super-synchronous stationary rotation resulting from the vanishing of the average tidal torque; (2) the capture into a 1:1 spin-orbit resonance (true synchronization). In these cases, the energy dissipation is controlled by the tidal harmonic with period equal to the orbital period (instead of the semi-diurnal tide) and the singularity due to the vanishing of the geometric phase lag does not exist. It is also shown that the true synchronization with non-zero eccentricity is only possible if an extra torque exists opposite to the tidal torque. The theory is developed assuming that this additional torque is produced by an equatorial permanent asymmetry in the companion. The results are model-dependent and the theory is developed only to the second degree in eccentricity and inclination (obliquity). It can easily be extended to higher orders, but formal accuracy will not be a real improvement as long as the physics of the processes leading to tidal lags is not better known.Comment: 30 pages, 7 figures, corrected typo

A comparative study of Tam3 and Ac transposition in transgenic tobacco and petunia plants

Transposition of the Anthirrinum majus Tam3 element and the Zea mays Ac element has been monitored in petunia and tobacco plants. Plant vectors were constructed with the transposable elements cloned into the leader sequence of a marker gene. Agrobacterium tumefaciens-mediated leaf disc transformation was used to introduce the transposable element constructs into plant cells. In transgenic plants, excision of the transposable element restores gene expression and results in a clearly distinguishable phenotype. Based on restored expression of the hygromycin phosphotransferase II (HPTII) gene, we established that Tam3 excises in 30% of the transformed petunia plants and in 60% of the transformed tobacco plants. Ac excises from the HPTII gene with comparable frequencies (30%) in both plant species. When the β-glucuronidase (GUS) gene was used to detect transposition of Tam3, a significantly lower excision frequency (13%) was found in both plant species. It could be shown that deletion of parts of the transposable elements Tam3 and Ac, removing either one of the terminal inverted repeats (TIR) or part of the presumptive transposase coding region, abolished the excision from the marker genes. This demonstrates that excision of the transposable element Tam3 in heterologous plant species, as documented for the autonomous element Ac, also depends on both properties. Southern blot hybridization shows the expected excision pattern and the reintegration of Tam3 and Ac elements into the genome of tobacco plants.