The effect of plant age on the chemical composition of fresh and ensiled Agave salmiana leaves

In the first study dry matter (DM), organic matter, crude protein (CP), neutral detergent fibre (NDF) and soluble carbohydrate (SC) concentrations were determined in whole leaves and the upper and lower sections of whole leaves of the Agave salmiana (Otto ex. Salm-Dyck) plant. The pH and saponin concentration were measured in aqueous extracts from these leaves. The leaves were collected from plants at the young (ca. 12 years old), bud (ca. 14 years old) and mature (ca. 16 years old) stages of growth. The CP level of young Agave (48 g/kg DM) leaves was higher than in leaves from the bud (38 g/kg DM) and mature (43 g/kg DM) stages, and higher in the upper (51 g/kg DM) than in the lower (35 g/kg DM) leaf sections. The leaves at the bud stage contained lower NDF (189 g/kg DM) but higher SC (358 g/kg DM) levels than those of mature (272 g NDF, 247 g SC/kg DM) and young (273 g NDF, 189 g SC) plants. The saponin content of leaves was higher in the mature (11.1 g/kg DM) than in the bud stage (7.5 g/kg DM). In the second study the chemical composition of whole leaves from young, bud and mature micro-ensilaged (3.5 kg as fed) Agave was determined over a 36 weeks fermentation period. Agave silage had acceptable chemical characteristics. As time of fermentation increased, a linear decrease in DM and saponin concentration, a linear increase in NDF and lactic acid levels and a quadratic increase of pH values and ammonia-N concentrations were recorded. Both fresh and ensilaged leaves of the mature and the bud stages were the most desirable maturity stages of Agave to be utilised as feed for ruminants. Keywords: Agave salmiana, chemical composition, magueySouth African Journal of Animal Science Vol. 38 (1) 2008: pp. 43-5

Resource Competition Triggers the Co-Evolution of Long Tongues and Deep Corolla Tubes

Background: It is normally thought that deep corolla tubes evolve when a plant’s successful reproduction is contingent on having a corolla tube longer than the tongue of the flower’s pollinators, and that pollinators evolve ever-longer tongues because individuals with longer tongues can obtain more nectar from flowers. A recent model shows that, in the presence of pollinators with long and short tongues that experience resource competition, coexisting plant species can diverge in corolla-tube depth, because this increases the proportion of pollen grains that lands on co-specific flowers. Methodology/Principal Findings: We have extended the model to study whether resource competition can trigger the coevolution of tongue length and corolla-tube depth. Starting with two plant and two pollinator species, all of them having the same distribution of tongue length or corolla-tube depth, we show that variability in corolla-tube depth leads to divergence in tongue length, provided that increasing tongue length is not equally costly for both species. Once the two pollinator species differ in tongue length, divergence in corolla-tube depth between the two plant species ensues. Conclusions/Significance: Co-evolution between tongue length and corolla-tube depth is a robust outcome of the model, obtained for a wide range of parameter values, but it requires that tongue elongation is substantially easier for one pollinator species than for the other, that pollinators follow a near-optimal foraging strategy, that pollinators experienc

Charged particle-like branes in ABJM

We study the effect of adding lower dimensional brane charges to the 't Hooft monopole, di-baryon and baryon vertex configurations in $AdS_4 \times \mathbb{P}^3$. We show that these configurations capture the background fluxes in a way that depends on the induced charges, and therefore, require additional fundamental strings in order to cancel the worldvolume tadpoles. The study of the dynamics reveals that the charges must lie inside some interval in order to find well defined configurations, a situation familiar from the baryon vertex in $AdS_5 \times S^5$ with charges. For the baryon vertex and the di-baryon the number of fundamental strings must also lie inside an allowed interval. Our configurations are sensitive to the flat $B$-field recently suggested in the literature. We make some comments on its possible role. We also discuss how these configurations are modified in the presence of a non-zero Romans mass.Comment: 31 pages, 14 figures, discussion of charges improved, published versio

Baryonic symmetries and M5 branes in the AdS_4/CFT_3 correspondence

We study U(1) symmetries dual to Betti multiplets in the AdS_4/CFT_3 correspondence for M2 branes at Calabi-Yau four-fold singularities. Analysis of the boundary conditions for vector fields in AdS_4 allows for a choice where wrapped M5 brane states carrying non-zero charge under such symmetries can be considered. We begin by focusing on isolated toric singularities without vanishing six-cycles, and study in detail the cone over Q^{111}. The boundary conditions considered are dual to a CFT where the gauge group is U(1)^2 x SU(N)^4. We find agreement between the spectrum of gauge-invariant baryonic-type operators in this theory and wrapped M5 brane states. Moreover, the physics of vacua in which these symmetries are spontaneously broken precisely matches a dual gravity analysis involving resolutions of the singularity, where we are able to match condensates of the baryonic operators, Goldstone bosons and global strings. We also argue more generally that theories where the resolutions have six-cycles are expected to receive non-perturbative corrections from M5 brane instantons. We give a general formula relating the instanton action to normalizable harmonic two-forms, and compute it explicitly for the Q^{222} example. The holographic interpretation of such instantons is currently unclear.Comment: 92 pages, 10 figure

Pathological vertebral fracture after stereotactic body radiation therapy for lung metastases. Case report and literature review.

<p>Abstract</p> <p>Background</p> <p>Stereotactic body radiation therapy (SBRT) is a radiation technique used in patients with oligometastatic lung disease. Lung and chest wall toxicities have been described in the patients but pathological vertebral fracture is an adverse effect no reported in patients treated with SBRT for lung metastases.</p> <p>Case presentation</p> <p>A 68-year-old woman with the diagnosis of a recurrence of a single lung metastatic nodule of urothelial carcinoma after third line of chemotherapy. The patient received a hypo-fractionated course of SBRT.A 3D-conformal multifield technique was used with six coplanar and one non-coplanar statics beams. A total dose of 48 Gy in three fractions over six days was prescribed to the 95% of the CTV. Ten months after the SBRT procedure, a CT scan showed complete response of the metastatic disease without signs of radiation pneumonitis. However, rib and vertebral bone toxicities were observed with the fracture-collapse of the 7^thand 8^thvertebral bodies and a fracture of the 7^thand 8^thleft ribs. We report a unique case of pathological vertebral fracture appearing ten months after SBRT for an asymptomatic growing lung metastases of urothelial carcinoma.</p> <p>Conclusion</p> <p>Though SBRT allows for minimization of normal tissue exposure to high radiation doses SBRT tolerance for vertebral bone tissue has been poorly evaluated in patients with lung tumors. Oncologists should be alert to the potential risk of fatal bone toxicity caused by this novel treatment. We recommend BMD testing in all woman over 65 years old with clinical risk factors that could contribute to low BMD. If low BMD is demonstrated, we should carefully restrict the maximum radiation dose in the vertebral body in order to avoid intermediate or low radiation dose to the whole vertebral body.</p

Foundations of Black Hole Accretion Disk Theory

This review covers the main aspects of black hole accretion disk theory. We begin with the view that one of the main goals of the theory is to better understand the nature of black holes themselves. In this light we discuss how accretion disks might reveal some of the unique signatures of strong gravity: the event horizon, the innermost stable circular orbit, and the ergosphere. We then review, from a first-principles perspective, the physical processes at play in accretion disks. This leads us to the four primary accretion disk models that we review: Polish doughnuts (thick disks), Shakura-Sunyaev (thin) disks, slim disks, and advection-dominated accretion flows (ADAFs). After presenting the models we discuss issues of stability, oscillations, and jets. Following our review of the analytic work, we take a parallel approach in reviewing numerical studies of black hole accretion disks. We finish with a few select applications that highlight particular astrophysical applications: measurements of black hole mass and spin, black hole vs. neutron star accretion disks, black hole accretion disk spectral states, and quasi-periodic oscillations (QPOs).Comment: 91 pages, 23 figures, final published version available at http://www.livingreviews.org/lrr-2013-

Set optimization - a rather short introduction

Recent developments in set optimization are surveyed and extended including various set relations as well as fundamental constructions of a convex analysis for set- and vector-valued functions, and duality for set optimization problems. Extensive sections with bibliographical comments summarize the state of the art. Applications to vector optimization and financial risk measures are discussed along with algorithmic approaches to set optimization problems