Growth rate of peanuts (Arachis hypogaea cv. Tennesse Red) on weed competition

Para estudiar el crecimiento del maní (Arachis hypogaea, cv. Tennesse Red) en competencia con malezas, se condujo un experimento en la Estación Experimental Agrícola Fabio Baudrit M., entre febrero y junio de 1984. El efecto detrimental que la interferencia de las malezas causó en el rendimiento del maní, se debió a una reducción en el Índice de Crecimiento Relativo, como consecuencia de la disminución en el Índice de Asimilación Neta y de la Razón de Área Foliar durante el periodo critico de competencia de malezas (30-70 DDS); antes o después de ese periodo, la presencia de las malezas no influyó negativamente en el rendimiento, al no afectar tampoco los componentes del Índice de Crecimiento Relativo.Growth rate of peanuts (Arachis hypogaea cv. Tennesse Red) on weed competition. An experiment was conducted in order to study the growth rate of peanuts (Arachis hipogaea cv. Tennesse Red), on weed competition, at the Fabio Baudrit Experiment Station, from February through June, 1984. The detrimental effect. that the weed interference caused to the peanut yield, was due to a decrease of Relative Growth Index as consequence of a diminution of the Net Assimilation Index and the Foliar Area Ratio during the critical period of weed competition (30-70 after planting). Before or after this period, weeds had no negative influence on the yield by affecting none of the components of the Relative Growth Index.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Estación Experimental Agrícola Fabio Baudrit Moreno (EEAFBM

EXPERIMENTAL ANALYSIS OF THE INFLUENCE OF HEAT SINK GEOMETRIC PARAMETERS ON NATURAL CONVECTION

In this work, the steady state heat transfer by natural convection in heat sinks with rectangular fins positioned vertically and horizontally was studied. The heat transfer by radiation was also considered. Several analyses were performed to determine the optimal number and position of the sensors used to measure the temperature on the heat sinks horizontally and vertically positioned. These analyses confirmed an almost uniform temperature distribution in the heat sink. This uniformity allowed the use of thermocouples only in the center of the heat sink. Twelve heat sinks were designed to study how their geometric parameters such as height, spacing and thickness of the fins, influence the heat transfer by free convection. In addition, in this work, two correlations using the dimensionless parameters Nusselt and Rayleigh are proposed. These correlations were obtained by using the results from the 12 heat sinks vertically and horizontally positioned considering a temperature range between 20 °C and 100 °C. Furthermore, studies were done to identify which of the 12 analyzed heat sinks managed to remove the greatest amount of heat in a given temperature range. The results were compared with those obtained from empirical correlations found in literature

Planck Scale Physics and the Testability of SU(5) Supergravity GUT

GUT scale threshold corrections in minimal SU(5) supergravity grand unification are discussed. It is shown that predictions may be made despite uncertainties associated with the high energy scale. A bound relating the strong coupling constant to the mass scales associated with proton decay and supersymmetry is derived, and a sensitive probe of the underlying theory is outlined. In particular, low energy measurements can in principle determine the presence of Planck scale ($1 / {{\rm M}_{\rm Pl}}$) terms.Comment: 12 pages, REVTeX, 2 figures included in an uuencoded Z-compressed PostScript file. Ready to print PostScript version (with figures) may be picked up at ftp://phys.tamu.edu/urano/planck/paper_prep.p

In utero protein restriction causes growth delay and alters sperm parameters in adult male rats

<p>Abstract</p> <p>Background</p> <p>Recent studies have supported the concept of "fetal programming" which suggests that during the intrauterine development the fetus may be programmed to develop diseases in adulthood. The possible effects of <it>in utero </it>protein restriction on sexual development of rat male offspring were evaluated in the present study.</p> <p>Methods</p> <p><it>Pregnant </it>Wistar rats were divided into two experimental groups: one group treated with standard chow (SC, n = 8, 17% protein) and the other group treated with hypoproteic chow (HC, n = 10, 6% protein) throughout gestation. After gestation the two experimental groups received standard chow. To evaluate the possible late reproductive effects of <it>in utero </it>protein restriction, the male offspring of both groups were assessed at different phases of sexual development: prepubertal (30 days old); peripubertal (60 days old); adult (90 days old). Student's t-test and Mann-Whitney test were utilized. Differences were considered significant when p < 0.05.</p> <p>Results</p> <p>We found that <it>in utero </it>protein restriction reduced the body weight of male pups on the first postnatal day and during the different sexual development phases (prepubertal, peripubertal and adult). During adulthood, Sertoli cell number, sperm motility and sperm counts in the testis and epididymal cauda were also reduced in HC. Furthermore, the numbers of sperm presenting morphological abnormalities and cytoplasmic drop retention were higher in HC.</p> <p>Conclusions</p> <p>In conclusion, <it>in utero </it>protein restriction, under these experimental conditions, causes growth delay and alters male reproductive-system programming in rats, suggesting impairment of sperm quality in adulthood.</p

Co-existence of virulence factors and antibiotic resistance in new Klebsiella pneumoniae clones emerging in south of Italy

Background: Endemic presence of Klebsiella pneumoniae resistant to carbapenem in Italy has been due principally to the clonal expansion of CC258 isolates; however, recent studies suggest an ongoing epidemiological change in this geographical area. Methods: 50 K. pneumoniae strains, 25 carbapenem-resistant (CR-Kp) and 25 susceptible (CS-Kp), collected from march 2014 to march 2016 at the Laboratory of Bacteriology of the Paolo Giaccone Polyclinic University hospital of Palermo, Italy, were characterized for antibiotic susceptibility and fully sequenced by next generation sequencing (NGS) for the in silico analysis of resistome, virulome, multi-locus sequence typing (MLST) and core single nucleotide polymorphism (SNP) genotypes Results: MLST in silico analysis of CR-Kp showed that 52% of isolates belonged to CC258, followed by ST395 (12%), ST307 (12%), ST392 (8%), ST348 (8%), ST405 (4%) and ST101 (4%). In the CS-Kp group, the most represented isolate was ST405 (20%), followed by ST392 and ST15 (12%), ST395, ST307 and ST1727 (8%). The in silico β-lactamase analysis of the CR-Kp group showed that the most detected gene was blaSHV (100%), followed by blaTEM (92%), blaKPC (88%), blaOXA (88%) and blaCTX-M (32%). The virulome analysis detected mrk operon in all studied isolates, and wzi-2 was found in three CR-Kp isolates (12%). Furthermore, the distribution of virulence genes encoding for the yersiniabactin system, its receptor fyuA and the aerobactin system did not show significant distribution differences between CR-Kp and CS-Kp, whereas the Klebsiella ferrous iron uptake system (kfuA, kfuB and kfuC genes), the two-component system kvgAS and the microcin E495 were significantly (p < 0.05) prevalent in the CS-Kp group compared to the CR-Kp group. Core SNP genotyping, correlating with the MLST data, allowed greater strain tracking and discrimination than MLST analysis. Conclusions: Our data support the idea that an epidemiological change is ongoing in the Palermo area (Sicily, Italy). In addition, our analysis revealed the co-existence of antibiotic resistance and virulence factors in CR-Kp isolates; this characteristic should be considered for future genomic surveillance studies

A retrospective whole-genome sequencing analysis of carbapenem and colistin-resistant klebsiella pneumoniae nosocomial strains isolated during an MDR surveillance program

Multidrug-resistant Klebsiella pneumoniae (MDR Kp), in particular carbapenem-resistant Kp (CR-Kp), has become endemic in Italy, where alarming data have been reported on the spread of colistin-resistant CR-Kp (CRCR-Kp). During the period 2013–2014, 27 CRCR-Kp nosocomial strains were isolated within the Modena University Hospital Policlinico (MUHP) multidrug resistance surveillance program. We retrospectively investigated these isolates by whole-genome sequencing (WGS) analysis of the resistome, virulome, plasmid content, and core single nucleotide polymorphisms (cSNPs) in order to gain insights into their molecular epidemiology. The in silico WGS analysis of the resistome revealed the presence of genes, such as blaKPC, related to the phenotypically detected resistances to carbapenems. Concerning colistin resistance, the plasmidic genes mcr 1–9 were not detected, while known and new genetic variations in mgrB, phoQ, and pmrB were found. The virulome profile revealed the presence of type-3 fimbriae, capsular polysaccharide, and iron acquisition system genes. The detected plasmid replicons were classified as IncFIB(pQil), IncFIB(K), ColRNAI, IncX3, and IncFII(K) types. The cSNPs genotyping was consistent with the multi locus sequence typing (MLST) and with the distribution of mutations related to colistin resistance genes. In a nosocomial drug resistance surveillance program, WGS proved to be a useful tool for elucidating the spread dynamics of CRCR-Kp nosocomial strains and could help to limit their diffusion

Método de aclimatização de mudas de orquídeas em garrafas PET.

bitstream/item/55348/1/CIT11003.pd

The RNA Helicase DDX6 Controls Cellular Plasticity by Modulating P-Body Homeostasis

Post-transcriptional mechanisms have the potential to influence complex changes in gene expression, yet their role in cell fate transitions remains largely unexplored. Here, we show that suppression of the RNA helicase DDX6 endows human and mouse primed embryonic stem cells (ESCs) with a differentiation-resistant, “hyper-pluripotent” state, which readily reprograms to a naive state resembling the preimplantation embryo. We further demonstrate that DDX6 plays a key role in adult progenitors where it controls the balance between self-renewal and differentiation in a context-dependent manner. Mechanistically, DDX6 mediates the translational suppression of target mRNAs in P-bodies. Upon loss of DDX6 activity, P-bodies dissolve and release mRNAs encoding fate-instructive transcription and chromatin factors that re-enter the ribosome pool. Increased translation of these targets impacts cell fate by rewiring the enhancer, heterochromatin, and DNA methylation landscapes of undifferentiated cell types. Collectively, our data establish a link between P-body homeostasis, chromatin organization, and stem cell potency

Cloud Computing for Climate Modelling: Evaluation, Challenges and Benefits

Cloud computing is a mature technology that has already shown benefits for a wide range of academic research domains that, in turn, utilize a wide range of application design models. In this paper, we discuss the use of cloud computing as a tool to improve the range of resources available for climate science, presenting the evaluation of two different climate models. Each was customized in a different way to run in public cloud computing environments (hereafter cloud computing) provided by three different public vendors: Amazon, Google and Microsoft. The adaptations and procedures necessary to run the models in these environments are described. The computational performance and cost of each model within this new type of environment are discussed, and an assessment is given in qualitative terms. Finally, we discuss how cloud computing can be used for geoscientific modelling, including issues related to the allocation of resources by funding bodies. We also discuss problems related to computing security, reliability and scientific reproducibilityS