Hydrobiology of Colombo (Beira) Lake, 1. Diurnal variations in temperature, hydrochemical factors and zooplankton

An extensive study of the hydrobiology of the Colombo Lake was initiated by the authors in May 1969 as a contribution to the International Biological Program (Productivity of freshwater communities) by the Department of Zoology, Vidyalankara University of Ceylon, Kelaniya. The Colombo Lake often referred to as the Beira Lake covers an area of approximately 160 acres. The water is usually very turbid with a greenish blue appearance due to the presence of large quantities of blue green algae

Epidermal growth factor receptor (EGFR) mutations in lung cancer: preclinical and clinical data

Lung cancer leads cancer-related mortality worldwide. Non-small-cell lung cancer (NSCLC), the most prevalent subtype of this recalcitrant cancer, is usually diagnosed at advanced stages, and available systemic therapies are mostly palliative. The probing of the NSCLC kinome has identified numerous nonoverlapping driver genomic events, including epidermal growth factor receptor (EGFR) gene mutations. This review provides a synopsis of preclinical and clinical data on EGFR mutated NSCLC and EGFR tyrosine kinase inhibitors (TKIs). Classic somatic EGFR kinase domain mutations (such as L858R and exon 19 deletions) make tumors addicted to their signaling cascades and generate a therapeutic window for the use of ATP-mimetic EGFR TKIs. The latter inhibit these kinases and their downstream effectors, and induce apoptosis in preclinical models. The aforementioned EGFR mutations are stout predictors of response and augmentation of progression-free survival when gefitinib, erlotinib, and afatinib are used for patients with advanced NSCLC. The benefits associated with these EGFR TKIs are limited by the mechanisms of tumor resistance, such as the gatekeeper EGFR-T790M mutation, and bypass activation of signaling cascades. Ongoing preclinical efforts for treating resistance have started to translate into patient care (including clinical trials of the covalent EGFR-T790M TKIs AZD9291 and CO-1686) and hold promise to further boost the median survival of patients with EGFR mutated NSCLC

Signalling by tips

New molecules, including protein kinases, lipids and molecules that have neurotransmitter activities in animals have emerged as important players in tip-growing cells. Transcriptomics analysis reveals that the largest single class of genes expressed in pollen tubes encode signal transducers, reflecting the necessity to decode complex and diverse pathways that are associated with tip growth. Many of these pathways may use common intracellular second messengers, with ions and reactive oxygen species emerging as two major common denominators in many of the processes involved in tip growth. These second messengers might influence the actin cytoskeleton through known interactions with actin-binding proteins. In turn, changes in the dynamic properties of the cytoskeleton would define the basic polarity events needed to shape and modify tip-growing cells

About the fastest growth of Order Parameter in Models of Percolation

Can there be a `Litmus test' for determining the nature of transition in models of percolation? In this paper we argue that the answer is in the affirmative. All one needs to do is to measure the `growth exponent' $\chi$ of the largest component at the percolation threshold; $\chi < 1$ or $\chi = 1$ determines if the transition is continuous or discontinuous. We show that a related exponent $\eta = 1 - \chi$ which describes how the average maximal jump sizes in the Order Parameter decays on increasing the system size, is the single exponent that describes the finite-size scaling of a number of distributions related to the fastest growth of the Order Parameter in these problems. Excellent quality scaling analysis are presented for the two single peak distributions corresponding to the Order Parameters at the two ends of the maximal jump, the bimodal distribution constructed by interpolation of these distributions and for the distribution of the maximal jump in the Order Parameter.Comment: 8 pages, 9 figure

Tachyon Condensation and Black Strings

We show that under certain conditions, closed string tachyon condensation produces a topology changing transition from black strings to Kaluza-Klein "bubbles of nothing." This can occur when the curvature at the horizon is much smaller than the string scale, so the black string is far from the correspondence point when it would make a transition to an excited fundamental string. This provides a dramatic new endpoint to Hawking evaporation. A similar transition occurs for black p-branes, and can be viewed as a nonextremal version of a geometric transition. Applications to AdS black holes and the AdS soliton are also discussed.Comment: 23 pages, 1 figure, v2: references adde

Evaluation of the AR4 CMIP3 and the AR5 CMIP5 model and projections for precipitation in northeast Brazil

This article compares the sensitivity of IPCC CMIP3-AR4 and CMIP5-AR5 models used on the latest reports from the Intergovernmental Panel on Climate Change (IPCC) in representing the annual average variations (austral summer and autumn) on three regions in Northeastern Brazil (NNEB) for the periods 1979&#8211;2000 using the CMAP (Climatology Merged Analysis of Precipitation) data as reference. The three areas of NNEB chosen for this analysis were the semiarid, eastern, and southern regions. The EOF analysis was performed to investigate how the coupled models resolve the temporal variability of the spatial modes in the Tropical Atlantic Sea Surface Temperature (SST), which drives the interannual variations of the rainfall in the Northeastern Brazil. CMIP3-AR4 and CMIP5-AR5 models presented a good representation of the annual cycle of precipitation. Results from correlation and mean absolute error analysis indicate that both CMIP3 and CMIP5 models produce large errors and barely capture the interannual rainfall variance during austral summer and autumn in Northeast Brazil, this features is closely related to the poor representation of the modes of SST variability in the Tropical Atlantic Ocean. For the summer and autumn rainfall projections (2040&#8211;2070) in the semiarid region, there was no convergence between the CMIP3 and CMIP5 models. During the summer and autumn in the eastern sector, both the CMIP3 and CMIP5 models projected rainfall above the mean for the 2040&#8211;2070 period

VULNERABILIDADE FÍSICA DO SOLO NA SERRA DO TEPEQUÉM-RR: ANÁLISE DA ATIVIDADE EROSIVA LINEAR

A serra do Tepequém foi palco de intensa atividade garimpeira diamantífera que ao longo das últimas décadas tem contribuído com o processo erosivo revelado através de feições lineares. Além da influência antrópica, a vulnerabilidade física, química e mineralógica dos solos foi determinante na formação e evolução das voçorocas. O objetivo do estudo foi identificar e descrever os principais fatores de vulnerabilidade física, química e mineralógica do solo envolvidos no processo erosivo

Influence of the number of fertilizer applications on the fruit quality of “pérola” pineapple

Procurou-se estudar a influência do número de aplicações de adubo químico na qualidade do fruto do abacaxi (Ananas comosus (L) Merr.) cultivar Pérola. O trabalho foi instalado em solo Vermelho-Amarelo Podzólico, consistindo dos seguintes tratamentos: A - aplicação total da fórmula NPK (5 g N, 3 g P2O5 e 3 g K2O), por planta, um mês após o plantio; B - metade da fórmula aplicada por planta, no 1° e 9° mês após o plantio; C - um terço da fórmula aplicada por planta no 1.°, 6.°e 9.° mês após o plantio; D - um quarto da fórmula aplicada,por planta no 1.°,6.°, 9.° e 10.° mês após o plantio. Os resultados alcançados indicaram não ter ocorrido significância estatística entre tratamentos para: peso do fruto, diâmetro do fruto, tamanho do fruto, sólidos solúveis totais, número de dias do plantio à floração e peso da coroa. Entretanto, verificou-se significância estatística para número de dias, do plantio à colheita, tamanho da coroa, e percentagem de suco no fruto, com os tratamentos A, B e C, em primeiro lugar, tendo sempre o tratamento A a melhor média. Os tratamentos D e C foram os que induziram maior precocidade para a formação completa do fruto; além disso, o tratamento C foi o que proporcionou a medula do fruto mais delgada.The work was carried out with "Pérola" (Ananas comosus L. Merr.) pineapple in a Red-Yellow Podzolic soil, studying the number of fertilizer applications. It showed some influence on the fruit quality. There were statistically significant differences among the fertilizer applications in relation to pith diameter of fruit, crown weight and percentage of juice. One application one month after planting time had the same effect of two or three split applications