Rendimiento productivo del Pennisetum sp. con varios niveles de sustancias húmicas más una base de enraizador

En la Provincia de Chimborazo, cantón Riobamba, se realizó la evaluación del comportamiento productivo forrajero del Pennisetum sp. (maralfalfa) aplicando varios niveles de sustancias húmicas (4, 5, 6 l/ha) más una base de enraizador (3 l/ha) en los suelos de la Facultad de Ciencias Pecuarias, para ser comparados con un tratamiento testigo, la investigación tuvo una duración de 60 días. Los datos obtenidos fueron analizados bajo un Diseño Completamente al Azar, con 5 repeticiones, el TUE fue de 10 m2, para la comparación de medias se aplicó el estadístico Tukey (P≤0.01) y (P≤0.05); a su vez se realizó un análisis de regresión y correlación, mediante el programa estadístico SPSS versión Statistic 19. Al observar los resultados experimentales para la variable altura de la planta a los 15, 30 y 60 días no se registraron diferencias estadísticas. Los mejores rendimientos de forraje verde y materia seca se obtuvieron con T3. La mayor rentabilidad fue registrada por las parcelas fertilizadas con T3, alcanzando un beneficio/costo de 1,72. En tal virtud se recomienda la utilización de T3 por haberse registrado los mejores rendimientos productivos, menor costo de producción y mejor rentabilidad.

Estudio de las correlaciones entre valores genéticos de producción – reproducción y tipo de los toros Jersey en Ecuador

En la provincia de Chimborazo se analizaron las correlaciones entre valores genéticos de Producción, Tipo y Reproducción en toros de la raza Jersey, mediante el uso de una base de datos correspondiente a dichos toros disponible en EEUU y comercializados en Ecuador. Se seleccionaron 25 toros. Los datos fueron analizados mediante estadística descriptiva y a su vez se realizó un análisis de correlación lineal por el método de Pearson, utilizando el software SPSS versión Statistic 19. Para la correlación entre parámetros productivos y reproductivos, el 65% de las características no se correlacionan, es decir, son independientes; mientras que el parámetro tasa de preñez de las hijas (DPR) se correlaciona con la vida productiva (PL) y habitabilidad (LIV). Además, la tasa de concepción de las hijas (HCR) se correlaciona con la habilidad predicha de trasmisión de proteína (PTAP) y la tasa de concepción de la vaca (CCR) con la LIV. Con respecto a las correlaciones entre parámetros productivos y de tipo, se indica que el 88% de las características son independientes; mientras que hay correlación directa entre el temperamento lechero (DF) con la PTAP y la habilidad predicha de trasmisión de grasa (PTAF). Para la correlación entre parámetros reproductivos y de tipo, el 72% de las características son independientes, mientras que los que progresan de manera directa son: PTAT con la tasa de concepción del toro (SCR) y el índice ubre Jersey (JUI) con SCR, por lo que se recomienda a los productores, seleccionar los sementales tomando en consideración las características que se correlacionan, ya que influyen en el desarrollo del Hato.

The Impact of African Dust on Air Quality in the Caribbean Basin

Symposium on Airborne Dust, Climate Change, and Human Health; Miami, Florida, 19–21 May 2015

Characterization and preclinical development of LY2603618: a selective and potent Chk1 inhibitor

Interference with DNA damage checkpoints has been demonstrated preclinically to be a highly effective means of increasing the cytotoxicity of a number of DNA-damaging cancer therapies. Cell cycle arrest at these checkpoints protects injured cells from apoptotic cell death until DNA damage can be repaired. In the absence of functioning DNA damage checkpoints, cells with damaged DNA may proceed into premature mitosis followed by cell death. A key protein kinase involved in activating and maintaining the S and G2/M checkpoints is Chk1. Pharmacological inhibition of Chk1 in the absence of p53 functionality leads to abrogation of DNA damage checkpoints and has been shown preclinically to enhance the activity of many standard of care chemotherapeutic agents. LY2603618 is a potent and selective small molecule inhibitor of Chk1 protein kinase activity in vitro (IC(50) = 7 nM) and the first selective Chk1 inhibitor to enter clinical cancer trials. Treatment of cells with LY2603618 produced a cellular phenotype similar to that reported for depletion of Chk1 by RNAi. Inhibition of intracellular Chk1 by LY2603618 results in impaired DNA synthesis, elevated H2A.X phosphorylation indicative of DNA damage and premature entry into mitosis. When HeLa cells were exposed to doxorubicin to induce a G2/M checkpoint arrest, subsequent treatment with LY2603618 released the checkpoint, resulting in cells entering into metaphase with poorly condensed chromosomes. Consistent with abrogation of the Chk1 and p53-dependent G2/M checkpoint, mutant TP53 HT-29 colon cancer cells were more sensitive to gemcitabine when also treated with LY2603618, while wild-type TP53 HCT116 cells were not sensitized by LY2603618 to gemcitabine. Treatment of Calu-6 human mutant TP53 lung cancer cell xenografts with gemcitabine resulted in a stimulation of Chk1 kinase activity that was inhibited by co-administration of LY2603618. By all criteria, LY2603618 is a highly effective inhibitor of multiple aspects of Chk1 biology.

A model for the control of malaria using genetically modified vectors

Recent works have considered the problem of using transgenic mosquitoes to control a malaria epidemic. These insects have been genetically engineered to reduce their capacity to infect humans with malaria parasites. We analyze a model of the mosquito population dynamics when genetically modified individuals are introduced into a wild type population so that the effect of their introduction can be assessed. The model describes the dynamics of gene selection under sexual reproduction in a closed vector population. Our results show that the fitness of the resulting heterozygous population is the key parameter for the success of the invasion, independently of the fitness of homozygous vectors. The vector population dynamics model is then combined with an epidemiological model to study the feasibility of controlling a malaria epidemic. Basic reproductive numbers are calculated for both models, and conditions are obtained for preventing reappearance of the epidemic. Simulations on this model show that it may be possible to reduce or even eradicate the epidemic only if the heterozygous population is better adapted than the wild type. They also show that this can be achieved without completely eliminating the wild type mosquitoes.

113 EFFECT OF SOME FACTORS ON CONCEPTION RATE IN ALPACAS UNDER PERUVIAN HIGHLAND CONDITION

Alpacas are a domestic species of South American camelids with a great importance to highland people because of their high-quality fibre production. However, their reproductive performance has been reported to be poor, with a birth rate of 50% under the Andean community’s conditions. Two experiments were designed to evaluate the effect of some factors on the pregnancy rate of alpacas at first service in lactating, 3- to 8-years old, without parity problems. The objective of the first experiment (n = 85) was to evaluate the effect of age (G1: 3, G2: 4 to 5, G3: ≥ 6 years old); mating time (G1: 15 min, G2: 16–24 min, G3: ≥ 25 min), and interval from parturition to mating (G1: 20 days, G2: ≥ 20 days) on first service conception rate. A second experiment (n = 174) evaluated the effect of month of calving (January, February, or March) on conception rate in females with a postpartum interval ≥20 days. Animals were mated with male of good fertility after a receptivity test and confirmation of presence of a dominant follicle ≥7 mm by ultrasonography. Pregnancy was determined by ultrasonography 25 days after mating. Proportional data were compared by Fisher’s exact test. In the first experiment, conception rates were 57.9, 66.7, and 47.2% in females of G1, G2, and G3, respectively (P ≤ 0.05); 50.0, 54.5, and 59.0% in females with mating time of 15, 16–24, or ≥ 25 min of mating; 48.0 and 59.4% in those with a postpartum interval <20 days and ≥20 days (P ≤ 0.05). In the second experiment, conception rates were 58.3, 70.7, and 82.1% in alpacas calving in January, February, and March, respectively (P ≤ 0.05). The results suggest that age of female, postpartum interval, and month of calving are factors that affect conception rates in alpacas. Therefore, a reproductive management system that includes these factors would improve the pregnancy rate in alpacas under highland Peruvian conditions. Consejo Superior de Investigacion – UNMSM.

Vitreoretinal alterations following laser in situ keratomileusis: clinical and experimental studies

BACKGROUND

The presence of vitreoretinal changes following laser in situ keratomileusis in myopia is evaluated.

METHODS

Clinically, 50 patients (100 eyes) with marked anisometropic myopia, 50 low-myopic eyes (<4.00 D) and 50 high-myopic eyes (>7.00 D) were prospectively evaluated pre- and postoperatively for the presence of newly recognized entoptic phenomena (vitreous floaters, light flashes, or both), and for vitreoretinal changes using indirect depressed fundus examination, a +90 D preset lens, Goldman three-mirror contact lens, and kinetic ultrasound (KU) before and after bilateral LASIK. Patients with previous partial or total posterior vitreous cortex detachment (PVD) were excluded. Experimentally, groups of adult pigs underwent KU, retinal fluorescein angiography (FA), and electroretinography (ERG) before and after applying the microkeratome suction ring for 30 s.

RESULTS

Clinically, 8% (4 eyes) had positive perception of postoperative vitreous floaters in the low myopia group, and 32% (16 eyes) in the high myopia group. Postoperative light flashes were noted only in the high myopia group, in 12% of cases. Partial or total posterior vitreous cortex detachment was detected by biomicroscopy in 2% (1 eye) of the low and in 10% (5 eyes) of the high myopia group and by KU in 4% (2 eyes) of the low and in 24% (12 eyes) of the high myopia group. Experimentally, 2 pig eyes out of 12 developed partial PVD by KU, immediately after microkeratome suction ring application. All pig eyes showed significantly diminished ERG amplitudes during and immediately after suction ring application. No FA changes or delays in retinal circulation time were noted during or immediately after removal of the suction ring.

CONCLUSIONS

Vitreoretinal alterations after LASIK were demonstrated clinically mainly by KU in high myopes. Experimentally, PVD were also demonstrated. Diminished ERG recordings with normal retinal circulation following suction ring application may suggest some transient choroidal circulation abnormalities.

Elliptic flow in Au+Au collisions at square root(S)NN = 130 GeV

Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at square root(S)NN = 130 GeV using the STAR Time Projection Chamber at the Relativistic Heavy Ion Collider. The elliptic flow signal, v2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

The price of peace: the personal and financial cost of paramilitary punishments in Northern Ireland

The aim of this study was to compare the injuries sustained during paramilitary punishments both before and after the onset of "peace" in Northern Ireland. A retrospective chart review was performed looking at age, injuries, treatments instituted, theatre time, length of hospital stay and overall cost of care. In the 10-month period before the ceasefire, 31 patients were treated after sustaining paramilitary punishment shootings. Mean age was 25.2 years. All patients had small entrance and exit wounds with minimal soft tissue disruption. A total of 18 fractures were recorded in 15 patients and 14 arteries required repair. Mean operative time was 2.6 h, mean hospital stay 7.61 days and mean cost per patient 3102 Pounds. In the following 10-month period 28 patients were admitted after punishments, only one of whom had been shot, all others had been beaten with sticks and clubs. Mean age was 27.4 years. In 52 limbs, 64 fractures were recorded and 44% of these were open; 15 of the fractures were Gustilo and Anderson Grade III or greater and 11 of the fractures were intra-articular. There were no arterial injuries. Mean operative time was 2.6 h, mean hospital stay 12.4 h and mean cost per patient 3849 Pounds.

The nucleation of monomeric parallel beta-sheet-like structures and their self-assembly in aqueous solution

The aromatic diacid residue 4,6-dibenzofuranbispropionic acid (1) was designed to nucleate a parallel beta-sheet-like structure in small peptides in aqueous solution via a hydrogen-bonded hydrophobic cluster. Even though a 14-membered ring hydrogen bond necessary for parallel beta-sheet formation is favored in simple amides composed of 1, this hydrogen bonding interaction does not appear to be sufficient to nucleate parallel beta-sheet formation in the absence of hydrophobic clustering between the dibenzofuran portion of 1 and the hydrophobic side chains of the flanking alpha-amino acids. The subsequence --hydrophobic residue-1-hydrophobic residue-- is required for folding in the context of a nucleated two-stranded parallel beta-sheet structure. In all cases where the peptidomimetics can fold into two diastereomeric parallel beta-sheet structures having different hydrogen bonding networks, these conformations appear to exchange rapidly. The majority of the parallel beta-sheet structures evaluated herein undergo linked intramolecular folding and self-assembly, affording a fibrillar beta-sheet quaternary structure. To unlink folding and assembly, asymmetric parallel beta-sheet structures incorporating N-methylated alpha-amino acid residues have been synthesized using a new solid phase approach. Residue 1 facilitates the folding of several peptides described within affording a monomeric parallel beta-sheet-like structure in aqueous solution, as ascertained by a variety of spectroscopic and biophysical methods, increasing our understanding of parallel beta-sheet structure.

Isolation and virological characterization of HIV-1 in Cuba. Relationship with the clinical status of the patients

The objective of this paper is the isolation and biological characterization of HIV-1 from patients at different clinical status of the disease. Clinical, epidemiological and virological aspects of 54 infected people were studied. Isolate HIV-1 strains were characterized and classified in relation with replication kinetics and cellular tropism as well as syncytium inducing (SI), and non syncytium inducing (NSI) capacity. The biological phenotype of viral isolates was correlated with the clinical status of each patient. HIV was isolated from 92.8% AIDS patients and 46.1% asymptomatic seropositive patients, 12 out of 26 strains of AIDS patients were classified rapid high (RH) and SI, however 2 out of 12 strains of asymptomatic seropositive carriers were considered similar too. The percentage of recovered viral isolates correlates with the patient's clinical status, and the association existing between the isolate biological phenotype and the clinical status of the infection in most of the cases, but not in all was demonstrated.

Purification and characterization of the extracellular aspartyl proteinase of Candida albicans: removal of extraneous proteins and cell wall mannoprotein and evidence for lack of glycosylation

Aspartyl proteinase (AP) is an extracellular enzyme of Candida albicans implicated as a pathogenic factor. Previous reports on the purification and characterization of AP suggested that a single DEAE-Sephadex chromatographic step was sufficient for the removal of extraneous proteins and that the final product was glycosylated. We purified AP using a chromatographic series consisting of DEAE-Sephadex A25, Sephadex G75 and rechromatography on DEAE-Sephadex A25. Use of DEAE-Sephadex alone did not remove extraneous proteins and removed little contaminating mannoprotein (MP). The addition of a Sephadex G75 column to the purification scheme removed the majority of contaminating MP and proteins. The final DEAE-Sephadex A25 chromatographic step resulted in (a) removal of detectable extraneous proteins, (b) removal of immunologically detectable MP by dot blot and Western blot enzyme immunoassay, (c) loss of periodic acid-silver stain positivity, and (d) a high AP yield (1295 U l-1) and specific activity (1749 U mg-1). We conclude that a single DEAE-Sephadex A25 purification step is insufficient to remove extraneous proteins and MP, which could interfere with the production of AP-specific antibodies and the dissection of moieties responsible for immune reactivity. Reports of periodic acid-Schiff or anthrone positivity of AP preparations may reflect the presence of extraneous MP, which can be removed by the chromatographic series we describe.

Heterogeneity of the purified extracellular aspartyl proteinase from Candida albicans: characterization with monoclonal antibodies and N-terminal amino acid sequence analysis

Three dominant proteins (41, 48, and 49 kDa) were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in purified preparations of the extracellular aspartyl proteinase (AP) of Candida albicans. All three proteins bound to the specific carboxyl proteinase ligand, pepstatin A, and were associated with maximum AP activity. The N-terminal amino acid sequence for the 48- and 49-kDa proteins matched that reported by others for AP, whereas the sequence for the 41-kDa protein was unique and was not homologous to any known protein. Time course studies demonstrated the simultaneous presence of all three proteins, supporting evidence that the 41- and 48-kDa proteins were not breakdown products of AP. Previous studies did not detect carbohydrate in SDS-polyacrylamide gels of purified AP preparations stained with periodic acid and silver, making glycosylation an unlikely explanation for the observed differences in the molecular masses of the proteins. Some monoclonal antibodies directed against the 49-kDa protein reacted with the 41- and 48-kDa proteins, indicating cross-reactive epitopes. Other monoclonal antibodies, however, reacted only with the 49-kDa protein. We conclude that three pepstatin A-binding proteins occur in purified AP preparations: two have the same amino acid N terminus as that reported for AP, whereas the third has a unique sequence. All three proteins should be considered when undertaking studies to determine the role of AP in candidal pathogenesis or when preparing specific antibodies for antigen capture assays.

Differentiation of rat hippocampal neurons induced by estrogen in vitro: effects on neuritogenesis and Na, K-ATPase activity

To gain insight into the mechanisms responsible for differentiation of hippocampal neurons growing in vitro, the effects of estrogen on neuritic development and on activity and distribution of isoforms of the Na, K-ATPase, were evaluated. Dissociated cells from hippocampi of 19-day-old rat fetuses were raised for 5 days in the presence or absence of 100 nM estradiol-17 beta (E2) in minimum essential medium supplemented either with 10% untreated fetal calf serum (MEM-10) or with 10% fetal calf serum previously adsorbed with dextran-activated charcoal (MEM-10-Cha). Cultures in MEM-10 showed larger neuritic length and increased levels of Na, K-ATPase activity than cultures in MEM-10-Cha. In cells cultured in MEM-10 medium, the addition of E2 resulted in selective enhancement of axonal length with a concomitant increase in the alpha-2 isoform of the Na, K-ATPase, whereas a decrease was found in the form most sensitive to ouabain; the total enzymatic activity remained unchanged. Conversely, in cultures raised in MEM-10-Cha, E2 did not affect Na, K-ATPase activity or neuritogenesis. These results show that two presumably independent probes of cellular differentiation of hippocampal neurons (i.e., neuritogenesis and patterns of Na, K-ATPase activity) were concurrently regulated by E2 and that such regulation depended on interaction with factor(s) present in calf serum. The well-known neuritogenic effect of E2 is hereby extended to hippocampal neurons, although for these cells it seems to be restricted to axons.