Thermostatistical description of small systems in nonequilibrium conditions: Energy conversion and harvesting

Hysteresis cycles are very important features of energy conversion and harvesting devices, such as batteries. The efficiency of these may be strongly affected by the physical size of the system. Here, we show that in systems which are small enough, the existence of physical boundaries which produce nonhomogeneities of the interaction potential gives rise to inflections and barriers in the associated free energy. This in turn brings on irreversible processes which can be triggered under suitable external conditions imposed by a heat bath. As an example, by controlling the temperature, the state of a small system may be impelled to oscillate between two different structural configurations or aggregation states avoiding equilibrium coexistence and therefore dissipating energy. This cyclical behavior associated with a hysteresis cycle may be prototypical of energy conversion, storage, or generating nanodevices, as exemplified by Li-ion insertion batteries.

Endothelin-1 does not mediate the endothelium-dependent hypoxic contractions of small pulmonary arteries in rats.

Various pulmonary artery preparations in vitro demonstrate sustained endothelium-dependent contractions upon hypoxia. To determine whether endothelin-1 could mediate this phenomenon, we examined the effect of bosentan, a new antagonist of both the ETA and ETB subtypes of the endothelin receptor. Small (300 pm) pulmonary arteries from rats were mounted on a myograph, precontracted with prostaglandin F2 alpha and exposed to hypoxia (PO2, 10 to 15 mm Hg, measured on-line) for 45 min. Endothelium-intact control rings exhibited a biphasic response, with a transient initial vasoconstriction (phase 1) followed by a second slowly developing sustained contraction (phase 2). Expressed in percent of the maximal response to 80 mmol/L KCl, the amplitudes of phase 1 (peak tension) and 2 (tension after 45 min of hypoxia) averaged 37 +/- 12% and 17 +/- 14%, respectively (n = 11). In endothelium-denuded rings, phase 1 persisted while the amplitude of phase 2 was reduced to 2 +/- 12% (p < 0.05, n = 8), showing the endothelium dependence of this contraction. Neither phase was significantly decreased in rings treated with 10(-5) mmol/L bosentan (38 +/- 15% and 17 +/- 12%, respectively, n = 6). The PO2 threshold for onset of hypoxic contraction was not significantly different among these three groups and averaged 32 +/- 24 mm Hg. In a separate experiment, we assessed the inhibitory effect of 10(-5) mol/L bosentan on the response to 10(-8) mol/L endothelin-I. Rings treated for 45 min with 10(-8) mol/L endothelin-1 alone exhibited a maximal contraction of 75 +/- 27% (n = 6). This was reduced to 4 +/- 17% (p < 0.01, n = 6) in rings treated with both 10(-8) mol/L endothelin-1 and 10(-5) mol/L bosentan. We conclude that complete blockade of all endothelin receptor subtypes has no effect on either endothelium-dependent or -independent hypoxic contractions in this preparation. This suggests that endothelial factors other than endothelin-I mediate the acute hypoxic contractions of small pulmonary arteries in the rat.

Prognostic factors affecting long-term outcomes in patients with resected stage IIIA pN2 non-small-cell lung cancer: 5-year follow-up of a phase II study.

The aim was to investigate the efficacy of neoadjuvant docetaxel-cisplatin and identify prognostic factors for outcome in locally advanced stage IIIA (pN2 by mediastinoscopy) non-small-cell lung cancer (NSCLC) patients. In all, 75 patients (from 90 enrolled) underwent tumour resection after three 3-week cycles of docetaxel 85 mg m-2 (day 1) plus cisplatin 40 or 50 mg m-2 (days 1 and 2). Therapy was well tolerated (overall grade 3 toxicity occurred in 48% patients; no grade 4 nonhaematological toxicity was reported), with no observed late toxicities. Median overall survival (OS) and event-free survival (EFS) times were 35 and 15 months, respectively, in the 75 patients who underwent surgery; corresponding figures for all 90 patients enrolled were 28 and 12 months. At 3 years after initiating trial therapy, 27 out of 75 patients (36%) were alive and tumour free. At 5-year follow-up, 60 and 65% of patients had local relapse and distant metastases, respectively. The most common sites of distant metastases were the lung (24%) and brain (17%). Factors associated with OS, EFS and risk of local relapse and distant metastases were complete tumour resection and chemotherapy activity (clinical response, pathologic response, mediastinal downstaging). Neoadjuvant docetaxel-cisplatin was effective and tolerable in stage IIIA pN2 NSCLC, with chemotherapy contributing significantly to outcomes.

Small-scale non-industrial private forest ownership in the United States : rationale and implications for forest management

Abstract

Topological phases in small quantum Hall samples

Topological order has proven a useful concept to describe quantum phase transitions which are not captured by the Ginzburg-Landau type of symmetry-breaking order. However, lacking a local order parameter, topological order is hard to detect. One way to detect it is via direct observation of anyonic properties of excitations which are usually discussed in the thermodynamic limit, but so far has not been realized in macroscopic quantum Hall samples. Here we consider a system of few interacting bosons subjected to the lowest Landau level by a gauge potential, and theoretically investigate vortex excitations in order to identify topological properties of different ground states. Our investigation demonstrates that even in surprisingly small systems anyonic properties are able to characterize the topological order. In addition, focusing on a system in the Laughlin state, we study the robustness of its anyonic behavior in the presence of tunable finite-range interactions acting as a perturbation. A clear signal of a transition to a different state is reflected by the system's anyonic properties.

Small but thick enough-the Arabidopsis hypocotyl as a model to study secondary growth.

The continuous production of vascular tissues through secondary growth results in radial thickening of plant organs and is pivotal for various aspects of plant growth and physiology, such as water transport capacity or resistance to mechanical stress. It is driven by the vascular cambium, which produces inward secondary xylem and outward secondary phloem. In the herbaceous plant Arabidopsis thaliana (Arabidopsis), secondary growth occurs in stems, in roots and in the hypocotyl. In the latter, radial growth is most prominent and not obscured by parallel ongoing elongation growth. Moreover, its progression is reminiscent of the secondary growth mode of tree trunks. Thus, the Arabidopsis hypocotyl is a very good model to study basic molecular mechanisms of secondary growth. Genetic approaches have succeeded in the identification of various factors, including peptides, receptors, transcription factors and hormones, which appear to participate in a complex network that controls radial growth. Many of these players are conserved between herbaceous and woody plants. In this review, we will focus on what is known about molecular mechanisms and regulators of vascular secondary growth in the Arabidopsis hypocotyl.

Nonperturbative semiclassical stability of de Sitter spacetime for small metric deviations

We consider the linearized semiclassical Einstein equations for small deviations around de Sitter spacetime including the vacuum polarization effects of conformal fields. Employing the method of order reduction, we find the exact solutions for general metric perturbations (of scalar, vector and tensor type). Our exact (nonperturbative) solutions show clearly that in this case de Sitter is stable with respect to small metric deviations and a late-time attractor. Furthermore, they also reveal a breakdown of perturbative solutions for a sufficiently long evolution inside the horizon. Our results are valid for any conformal theory, even self-interacting ones with arbitrarily strong coupling.

2012 Iowa Small Hospital Improvement Program (SHIP) Briefing and Survey Report, January 22, 2013

In August of 2012 the Iowa State Office of Rural Health (SORH) conducted a survey to determine the value of the Small Rural Hospital Improvement Program (SHIP) in Iowa. This survey was distributed to the 84 participating hospitals however, because some hospitals network their SHIP funds we only asked the contract administrators of the contracts to complete the survey. 58 of the 78 SHIP contract administrators completed the survey (74%). Background: SHIP brings in roughly $750,000.00 annually to Iowa to assist small Iowa hospitals. Average distribution of approximately $7,500 per hospital. Seventy three of ninety nine Iowa counties are represented.

The contribution of a pollinating seed predator to selection on Silene latifolia females.

Interactions, antagonistic or mutualistic, can exert selection on plant traits. We explored the role of Hadena bicruris, a pollinating seed predator, as a selective agent on its host, the dioecious plant Silene latifolia. We exposed females from artificial-selection lines (many, small flowers (SF) vs. few, large flowers (LF)) to this moth. Infestation did not differ significantly between lines, but the odds of attacked fruits aborting were higher in SF females. We partitioned selection between that caused by moth attack and that resulting from all other factors. In both lines, selection via moth attack for fewer, smaller flowers contrasted with selection via other factors for more flowers. In LF females, selection via the two components was strongest and selection via moth attack also favoured increased fruit abortion. This suggests that the moths act as more of a selective force on flower size and number via their predating than their pollinating role.