Growth Characteristics of Guinea Grass on the Semiarid South Coast of Puerto Rico, and the Effect of Nitrogen Fertilization on Forage Yields and Protein Content

The stocking level and hence the productive capacity of pastures in the nonirrigable, semiarid region of Puerto Rico is limited by the pasturage available during the approximately 5-month dry season of December to April. This, in turn, largely depends on the quantity and quality of the roughage carried over in the field from the wet season when an excess of forage is produced. The application of 100 pounds of nitrogen per acre to a closely grazed Guinea grass pasture toward the end of the wet season, November 1, resulted in a marked increase in the dry matter from 3,555 to 5,520 pounds per acre of protein yields from 238 to 486 pounds per acre, and in the protein content from 6.7 to 8.8 percent, of the forage carried over in the field for grazing toward the end of the dry season. Total yields of dry forage produced during the year following application of the fertilizer were increased from 9,710 to 12,645 pounds per acre. Total yields of protein were also increased by this treatment from 608 to 921 pounds per acre. About 50 percent of the nitrogen applied was recovered in the forage. Heavier applications of nitrogen tended to increase protein yields and also the protein content of the forage, but did not affect yields of dry matter. Through good management and proper fertilization with nitrogen it appears possible markedly to increase the carrying capacity of Guinea grass pastures in this area

Evidence for, and characterization of, a lipopolysaccharide-inducible adenosine A2 receptor in human tracheal gland serous cells

AbstractHuman tracheal glands are considered as the principle secretory structures in the bronchotracheal tree. In earlier studies, we successfully performed primary cultures of human tracheal gland (HTG) serous cells and noted that these cells were responsive to many secretagogues including purinergic agonists but not to the inflammatory mediator adenosine. In this study, we demonstrate that adenosine was capable of inducing stimulation of protein secretion by HTG serous cells which had previously been cultured in pro-inflammatory conditions (induced by lipopolysaccharide (LPS)). This stimulation was inhibited by 8-phenyltheophylline but not by dipyridamole, which is indicative of a P1 purinoceptor. This inducible receptor is of the adenosine A2 subtype [rank potency order: 5′-(N-ethyl)-carboxamidoadenosine (NECA) > adenosine > N6-(phenylisopropyl)-adenosine (PIA); and stimulation of adenylyl cyclase]. The adenosine-induced protein secretion was concentration-dependent, however, increased intracellular cyclic adenosine monophosphate (cAMP) was not dependent on the concentration of adenosine. The adenosine-induced secretion and the ATP-induced secretion were shown to be additive. This study concludes that there is evidence of a LPS-inducible adenosine A2 receptor in human tracheal gland serous cells

Controlling chaotic transport in a Hamiltonian model of interest to magnetized plasmas

We present a technique to control chaos in Hamiltonian systems which are close to integrable. By adding a small and simple control term to the perturbation, the system becomes more regular than the original one. We apply this technique to a model that reproduces turbulent ExB drift and show numerically that the control is able to drastically reduce chaotic transport

Trisomy 19 ependymoma, a newly recognized genetico-histological association, including clear cell ependymoma

Ependymal tumors constitute a clinicopathologically heterogeneous group of brain tumors. They vary in regard to their age at first symptom, localization, morphology and prognosis. Genetic data also suggests heterogeneity. We define a newly recognized subset of ependymal tumors, the trisomy 19 ependymoma. Histologically, they are compact lesions characterized by a rich branched capillary network amongst which tumoral cells are regularly distributed. When containing clear cells they are called clear cell ependymoma. Most trisomy 19 ependymomas are supratentorial WHO grade III tumors of the young. Genetically, they are associated with trisomy 19, and frequently with a deletion of 13q21.31-31.2, three copies of 11q13.3-13.4, and/or deletions on chromosome 9. These altered chromosomal regions are indicative of genes and pathways involved in trisomy 19 ependymoma tumorigenesis. Recognition of this genetico-histological entity allows better understanding and dissection of ependymal tumors

Possible regulation of CFTR-chloride channels by membrane-bound phosphatases in pancreatic duct cells

AbstractWe have studied CFTR-Cl− channels in non-CF CAPAN-1 and in CFTR-transfected CFPAC-PLJ-CFTR-6 epithelial cells from human pancreas. Theophylline and IBMX induced the opening of cell-attached CFTR-Cl− channels. Theophylline, IBMX and the alkaline phosphatase (AP) inhibitor levamisole enhanced the activity of excised channels and reduced by 70–75% the apical membrane-associated APs activity. Okadaic acid had no effect on APs and channel activities. A polyclonal anti-alkaline phosphatase antibody (which detected apical APs) reduced APs activity and activated quiescent excised chloride channels. These results suggest that CFTR channels may be regulated by membrane-bound phosphatases

High lysosomal activities in cystic fibrosis tracheal gland cells corrected by adenovirus-mediated CFTR gene transfer

AbstractHuman tracheal gland serous (HTGS) cells are now believed to be a major target of cystic fibrosis (CF) gene therapy. To evaluate the efficiency of adenovirus-mediated gene transfer in these cells we tested the adenovirus construction containing β-galactosidase cDNA. We observed that the endogenous β-galactosidase activity in cultured CF-HTGS cells was too strong to allow us to detect any exogenous β-galactosidase activity. Immunohistological study on sections of human tracheal tissue confirmed the presence of β-galactosidase in the serous component of the submucosal glands. We then looked for other lysosomal activities in normal and CF-HTGS cells. We showed that normal cells already have elevated enzyme values and that CF-HTGS cells contained 2–4-fold more β-galactosidase, α-fucosidase, α-mannosidase and β-glucuronidase activities than normal cells. An analysis of their kinetic constants has shown that this difference could be attributed to a lower Km of CF lysosomal enzymes. More importantly, these differences are eliminated after adenovirus-mediated CFTR gene transfer and not after β-galactosidase gene transfer

Duplications of KIAA1549 and BRAF screening by Droplet Digital PCR from formalin-fixed paraffin-embedded DNA is an accurate alternative for KIAA1549-BRAF fusion detection in pilocytic astrocytomas

Pilocytic astrocytomas represent the most common glioma subtype in young patients and account for 5.4% of all gliomas. They are characterized by alterations in the RAS–MAP kinase pathway, the most frequent being a tandem duplication on chromosome 7q34 involving the BRAF gene, resulting in oncogenic BRAF fusion proteins. BRAF fusion involving the KIAA1549 gene is a hallmark of pilocytic astrocytoma, but it has also been recorded in rare cases of gangliogliomas, 1p/19q co-deleted oligodendroglial tumors, and it is also a common feature of disseminated oligodendroglial-like leptomeningeal neoplasm. In some difficult cases, evidence for KIAA1549-BRAF fusion is of utmost importance for the diagnosis. Moreover, because the KIAA1549-BRAF fusion constitutively activates the MAP kinase pathway, it represents a target for drugs such as MEK inhibitors, and therefore, the detection of this genetic abnormality is highly relevant in the context of clinical trials applying such new approaches. In the present study, we aimed to use the high sensitivity of Droplet Digital PCR (DDPCR™) to predict KIAA1549-BRAF fusion on very small amounts of formalin-fixed paraffin-embedded tissue in routine practice. Therefore, we analyzed a training cohort of 55 pilocytic astrocytomas in which the KIAA1549-BRAF fusion status was known by RNA sequencing used as our gold standard technique. Then, we analyzed a prospective cohort of 40 pilocytic astrocytomas, 27 neuroepithelial tumors remaining difficult to classify (pilocytic astrocytoma versus ganglioglioma or diffuse glioma), 15 dysembryoplastic neuroepithelial tumors, and 18 gangliogliomas. We could demonstrate the usefulness and high accuracy (100% sensitivity and specificity when compared to RNA sequencing) of DDPCR™ to assess the KIAA1549-BRAF fusion from very low amounts of DNA isolated from formalin-fixed paraffin-embedded specimens. BRAF duplication is both necessary and sufficient to predict this fusion in most cases and we propose that this single analysis could be used in routine practice to save time, money, and precious tissue

Control of Hamiltonian chaos as a possible tool to control anomalous transport in fusion plasmas

It is shown that a relevant control of Hamiltonian chaos is possible through suitable small perturbations whose form can be explicitly computed. In particular, it is possible to control (reduce) the chaotic diffusion in the phase space of a Hamiltonian system with 1.5 degrees of freedom which models the diffusion of charged test particles in a turbulent electric field across the confining magnetic field in controlled thermonuclear fusion devices. Though still far from practical applications, this result suggests that some strategy to control turbulent transport in magnetized plasmas, in particular tokamaks, is conceivable. The robustness of the control is investigated in terms of a departure from the optimum magnitude, of a varying cut-off at large wave vectors, and of random errors on the phases of the modes. In all three cases, there is a significant region of maximum efficiency in the vicinity of the optimum control term.Comment: 17 pages, 21 figure