798 research outputs found
Application of remote sensing to state and regional problems
The author has identified the following significant results. The Lowndes County data base is essentially complete with 18 primary variables and 16 proximity variables encoded into the geo-information system. The single purpose, decision tree classifier is now operational. Signatures for the thematic extraction of strip mines from LANDSAT Digital data were obtained by employing both supervised and nonsupervised procedures. Dry, blowing sand areas of beach were also identified from the LANDSAT data. The primary procedure was the analysis of analog data on the I2S signal slicer
Research Notes : United States : Response of soybean strains to DPX-F6025 in hydroponics
Introduction: Previous work with DPX-F6025 (2-(([(4-chloro-6-methoxy-pyrimidine-2-yl) amino carbonyl] amino sulfonyl)) benzoic acid, ethyl ester) found differential strain response to increasing rates in hydroponics (Lloyd, 1985). Hanson (1984) reported differential strain response to a single rate of metribuzin in soybeans when evaluated in a hydroponic system similar to one developed by Barrentine et al. (1976). With known agronomic changes in soybeans associated with herbicide treatments, this study was undertaken to study the agronomic effects of DPX-F6025 on a randomly selected group of soybean strains when evaluated in a hydroponic system
Phenomenology of Sterile Neutrinos
The indications in favor of short-baseline neutrino oscillations, which
require the existence of one or more sterile neutrinos, are reviewed. In the
framework of 3+1 neutrino mixing, which is the simplest extension of the
standard three-neutrino mixing which can partially explain the data, there is a
strong tension in the interpretation of the data, mainly due to an
incompatibility of the results of appearance and disappearance experiments. In
the framework of 3+2 neutrino mixing, CP violation in short-baseline
experiments can explain the difference between MiniBooNE neutrino and
antineutrino data, but the tension between the data of appearance and
disappearance experiments persists because the short-baseline disappearance of
electron antineutrinos and muon neutrinos compatible with the LSND and
MiniBooNE antineutrino appearance signal has not been observed.Comment: 8 pages. Invited paper to NUFACT 11, XIIIth International Workshop on
Neutrino Factories, Super beams and Beta beams, 1-6 August 2011, CERN and
University of Geneva (Submitted to IOP conference series
Vasopressin pressor effects in critically ill children during evaluation for brain death and organ recovery.
BACKGROUND: Vasopressin (VP) shows promise as a pressor agent in animals and adult human cardiac arrest and resuscitation, but has not been studied for pressor effect in critically ill or arrested children. VP infusion is routine treatment for diabetes insipidus during brain death evaluation and organ recovery. We hypothesized that low dose VP infusion during organ recovery in critically ill children exerts a pressor effect, without major organ toxicity.
METHODS: 34 VP-treated and 29 age-matched critically ill controls (C) \u3c or =18 years were retrospectively reviewed during brain death evaluation and organ recovery. VP infusion protocol titrated VP dose clinically to urine output, with high variability. Pressor and inotrope management was titrated clinically to BP, cerebral perfusion and central venous pressures (when available) and peripheral perfusion with similar protocol targets for pre-load in VP and C groups. Outcome measures include dose, type and number of pressors and inotropes. Organ function was assessed at recovery and 48 h post-transplant by independent surgeon and transplant program organ function criteria. Analysis by Odds Ratio (OR), and chi-square.
RESULTS: VP dose averaged 0.041+/-0.069 U/kg/h. Average baseline mean arterial pressure (MAP) before VP infusion was 79+/-17 mmHg VP and 76+/-14 mm Hg C (P=0.6). Subsequent average MAP were: 82+/-21 mmHgVP after VP infusion versus 71+/-16 mmHg C (P=0.01) and 80+/-14 mmHg VP versus 68+/-22 mmHg C (P=0.01). Ability to wean/stop pressors and inotropes was: dopamine (14/23) 42% VP versus (10/26) 38% C (P=0.75), dobutamine (4/7) 57% VP versus (0/6) 0% C (P=0.026), epinephrine (4/5) 80% VP versus (0/6) 0% C (P=0.006), norepinephrine/phenylephrine (4/4) 100% VP versus (2/5) 40% C (P=0. 057). Alpha agonist pressor dependence was successfully weaned from 7/9 (78%) VP versus 0/9 (0%) C: odds ratio=7.3, (P
CONCLUSIONS: Low dose vasopressin infusion exerts a pressor effect in critically ill children treated for diabetes insipidus during brain death and organ recovery. VP treated patients were 7.3 times more likely to wean from alpha agonists than comparably managed age matched controls, without adverse affect on transplant organ function. We speculate that further prospective assessment of VP safety and efficacy as a pressor adjunct for resuscitation of critically ill children is warranted
Penetration depth of low-coherence enhanced backscattered light in sub-diffusion regime
The mechanisms of photon propagation in random media in the diffusive
multiple scattering regime have been previously studied using diffusion
approximation. However, similar understanding in the low-order (sub-diffusion)
scattering regime is not complete due to difficulties in tracking photons that
undergo very few scatterings events. Recent developments in low-coherence
enhanced backscattering (LEBS) overcome these difficulties and enable probing
photons that travel very short distances and undergo only a few scattering
events. In LEBS, enhanced backscattering is observed under illumination with
spatial coherence length L_sc less than the scattering mean free path l_s. In
order to understand the mechanisms of photon propagation in LEBS in the
subdiffusion regime, it is imperative to develop analytical and numerical
models that describe the statistical properties of photon trajectories. Here we
derive the probability distribution of penetration depth of LEBS photons and
report Monte Carlo numerical simulations to support our analytical results. Our
results demonstrate that, surprisingly, the transport of photons that undergo
low-order scattering events has only weak dependence on the optical properties
of the medium (l_s and anisotropy factor g) and strong dependence on the
spatial coherence length of illumination, L_sc, relative to those in the
diffusion regime. More importantly, these low order scattering photons
typically penetrate less than l_s into the medium due to low spatial coherence
length of illumination and their penetration depth is proportional to the
one-third power of the coherence volume (i.e. [l_s \pi L_sc^2 ]^1/3).Comment: 32 pages(including 7 figures), modified version to appear in Phys.
Rev.
Outcomes of interfacility critical care adult patient transport: a systematic review
INTRODUCTION: We aimed to determine the adverse events and important prognostic factors associated with interfacility transport of intubated and mechanically ventilated adult patients. METHODS: We performed a systematic review of MEDLINE, CENTRAL, EMBASE, CINAHL, HEALTHSTAR, and Web of Science (from inception until 10 January 2005) for all clinical studies describing the incidence and predictors of adverse events in intubated and mechanically ventilated adult patients undergoing interfacility transport. The bibliographies of selected articles were also examined. RESULTS: Five studies (245 patients) met the inclusion criteria. All were case-series and two were prospective in design. Due to the paucity of studies and significant heterogeneity in study population, outcome events, and results, we synthesized data in a qualitative manner. Pre-transport severity of illness was reported in only one study. The most common indication for transport was a need for investigations and/or specialist care (three studies, 220 patients). Transport modalities included air (fixed or rotor wing; 66% of patients) and ground (31%) ambulance, and commercial aircraft (3%). Transport teams included a physician in three studies (220 patients). Death during transfer was rare (n = 1). No other adverse events or significant therapeutic interventions during transport were reported. One study reported a 19% (28/145) incidence of respiratory alkalosis on arrival and another study documented a 30% overall intensive care unit mortality, while no adverse events or outcomes were reported after arrival in the three other studies. CONCLUSION: Insufficient data exist to draw firm conclusions regarding the mortality, morbidity, or risk factors associated with the interfacility transport of intubated and mechanically ventilated adult patients. Further study is required to define the risks and benefits of interfacility transfer in this patient population. Such information is important for the planning and allocation of resources related to transporting critically ill adults
An exact analytical solution for generalized growth models driven by a Markovian dichotomic noise
Logistic growth models are recurrent in biology, epidemiology, market models,
and neural and social networks. They find important applications in many other
fields including laser modelling. In numerous realistic cases the growth rate
undergoes stochastic fluctuations and we consider a growth model with a
stochastic growth rate modelled via an asymmetric Markovian dichotomic noise.
We find an exact analytical solution for the probability distribution providing
a powerful tool with applications ranging from biology to astrophysics and
laser physics
Acute Ingestion Of L-Arginine Alpha-Ketoglutarate Fails To Improve Muscular Strength And Endurance In ROTC Cadets
International Journal of Exercise Science 6(2) : 91-97, 2013. L-Arginine Alpha-Ketoglutarate (AAKG) is purported to stimulate the release of nitric oxide, and is suggested to facilitate muscular performance by increasing blood flow and increase oxygen and nutrient delivery to the working muscle. However, the ergogenic benefit of AAKG during resistance exercise has not been established. Therefore the purpose of this study was to investigate the effects of acute AAKG ingestion in active ROTC Cadets on measures of one-repetition maximal strength (1RM) and muscular endurance. Nineteen apparently healthy males ingested either AAKG (3 g) or a placebo 45 minutes prior to resistance testing in a randomized, double-blind crossover design. Initially, blood lactate (BLA) was obtained followed by 1RM testing on the barbell bench press and leg press. Upon determination of 1RM, participants completed repetitions to failure at 60% of 1RM. Blood lactate measures were immediately taken following the final repetition. Analysis revealed no significant differences between the conditions for bench press 1RM. Additionally, there were no differences between conditions for 1RM leg press, or for number of repetitions performed for the bench press or leg press. Blood lactate values did increase significantly from baseline to post-bench press in both the AAKG (t33 = 7.56, p \u3c 0.01) and placebo conditions (t33 = 8.45, p \u3c 0.01). Further, BLA lactate levels were also significantly greater post leg-press in the AAKG (t33 = 9.23, p \u3c 0.01) and placebo (t33 = 8.10, p \u3c 0.01). The results indicate that acute AAKG supplementation provides no ergogenic benefit in this study
Random paths and current fluctuations in nonequilibrium statistical mechanics
An overview is given of recent advances in nonequilibrium statistical
mechanics about the statistics of random paths and current fluctuations.
Although statistics is carried out in space for equilibrium statistical
mechanics, statistics is considered in time or spacetime for nonequilibrium
systems. In this approach, relationships have been established between
nonequilibrium properties such as the transport coefficients, the thermodynamic
entropy production, or the affinities, and quantities characterizing the
microscopic Hamiltonian dynamics and the chaos or fluctuations it may generate.
This overview presents results for classical systems in the escape-rate
formalism, stochastic processes, and open quantum systems
How Stands Collapse II
I review ten problems associated with the dynamical wave function collapse
program, which were described in the first of these two papers. Five of these,
the \textit{interaction, preferred basis, trigger, symmetry} and
\textit{superluminal} problems, were discussed as resolved there. In this
volume in honor of Abner Shimony, I discuss the five remaining problems,
\textit{tails, conservation law, experimental, relativity, legitimization}.
Particular emphasis is given to the tails problem, first raised by Abner. The
discussion of legitimization contains a new argument, that the energy density
of the fluctuating field which causes collapse should exert a gravitational
force. This force can be repulsive, since this energy density can be negative.
Speculative illustrations of cosmological implications are offered.Comment: 37 page
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