In vitro conservation of Cedrela fissilis Vellozo (Meliaceae),a native tree of the Brazilian Atlantic Forest

Two in vitro conservation methods have beendeveloped for the ex situ conservation of germplasm fromCedrela fissilis, an economically important tree of theBrazilian Atlantic Forest. The first method involves the medium-term storage, at 25°C, of artificial seeds comprising alginate encapsulatedvegetative propagules (shoot tips, cotyledonary and epicotyl nodal segments).Maximum post-storage (3 months) viabilities of 96–100% wereachieved for encapsulated shoot tips and cotyledonary nodal segments stored onwater-solidified agar (at 0.4–0.7% w/v). Encapsulated shoot tips storedfor 6 months on 0.4% (w/v) agar showed the highest survival rates(44%). Seeds of C. fissilis were successfully cryopreserved(100%) after direct immersion in liquid nitrogen. Ex situstorage procedures are now available for the medium- to long-term conservationof C. fissilis. These approaches offer new opportunitiesfor the conservation, sustainable management and utilization of this valuablefast growing timber tree.     

PINCH2 is a new five LIM domain protein, homologous to PINCHand localized to focal adhesions

PINCH is a five LIM domain protein involved in the regulation of integrin-mediated cell adhesion. It has been shown that PINCH interacts with integrin-linked kinase and Nck2. Here we describe a new isoform of PINCH, which we call PINCH2. Therefore, we rename PINCH to PINCH1. PINCH2 has an overall similarity of 92% to PINCH1 and contains five LIM domains like PINCH1. While protein and gene structure of the PINCH homologues are very similar and well conserved during evolution, we observed differential expression pattern of the mRNAs. Based on northern hybridization of mouse embryo RNA, PINCH1 is already detectable at E8.5. It is highly expressed during later stages of development and in all adult mouse tissues analyzed, with the highest levels in heart, lung, bladder, skin, and uterus. In contrast, significant PINCH2 expression starts at E14.5. In adult mice it is widely expressed, similar to PINCH1, but absent from spleen and thymus. In situ hybridization confirmed the Northern data and showed differential expression of PINCH1 and PINCH2 in embryonic intestine. Finally, we demonstrate that PINCH2 localizes to focal adhesions in NIH 3T3 cells and to Z-disks in primary rat cardiomyocytes.     

Bile Salt Hydrolase Activity and Resistance to Toxicity of Conjugated Bile Salts Are Unrelated Properties in Lactobacilli

Bacteria of numerous species isolated from the human gastrointestinal tract express bile salt hydrolase (BSH) activity. How this activity contributes to functions of the microorganisms in the gastrointestinal tract is not known. We tested the hypothesis that a BSH protects the cells that produce it from the toxicity of conjugated bile salts. Forty-nine strains of numerous Lactobacillus spp. were assayed to determine their capacities to express BSH activities (taurodeoxycholic acid [TDCA] hydrolase and taurocholic acid [TCA] hydrolase activities) and their capacities to resist the toxicity of a conjugated bile acid (TDCA). Thirty of these strains had been isolated from the human intestine, 15 had been recovered from dairy products, and 4 had originated from other sources. Twenty-six of the strains expressed both TDCA hydrolase and TCA hydrolase activities. One strain that expressed TDCA hydrolase activity did not express TCA hydrolase activity. Conversely, in one strain for which the assay for TDCA hydrolase activity gave a negative result there was evidence of TCA hydrolase activity. Twenty-five of the strains were found to resist the toxicity of TDCA. Fourteen of these strains were of human origin, nine were from dairy products, and two were from other sources. Of the 26 strains expressing both TDCA hydrolase and TCA hydrolase activities, 15 were resistant to TDCA toxicity, 6 were susceptible, and 5 gave inconclusive results. Of the 17 strains that gave negative results for either of the enzymes, 7 were resistant to the toxicity, 9 were susceptible, and 1 gave inconclusive results. These findings do not support the hypothesis tested. They suggest, however, that BSH activity is important at some level for lactobacillus colonization of the human intestine.     

New excitement in cognitive space: between place cells and spatial memory

Hippocampal principal neurons-'place cells'-exhibit location-specific firing. Recent work addresses the link between place cell activity and hippocampal memory function. New tasks that challenge spatial memory allow recording from single neurons, as well as ensembles of neurons, during memory computations, and insights into the cellular mechanisms of spatial memory are beginning to emerge.     

建立正常人肺血管容量的无创精确测量方法的初步报告*

目的: 由于传统呼吸调控环路忽略了对血液循环的决定性作用,肺（静脉）血管容量相关研究甚少,亟需建立肺血管容量测量方法。方法: 选择正常志愿者完成CT全肺扫描,图像数据经过计算机软件分析处理,从肺尖到肺底以40~50层进行肺野手工切划,相邻层间由计算机自动模拟连接,在去除干扰后进行全肺血管（≥0.6 mm）高精度三维立体成像技术处理,进而计算全肺和肺血管容积。结果: 12例正常志愿者从肺尖到肺底CT扫描图片层数为530±98（431~841）张。全肺和肺血管的总容积是3705±857（2398~5383）ml ,肺血管血液总的容积是125±32（94~201）ml。按肺静脉系统血管容量约为全肺血管血液容量一半计算,应该是63±16（47~100）ml。结论: 肺CT扫描数据分析三维立体成像建立肺血管容量无创测量方法精确可行。     

Fertilizer and manure equivalent rates on forage corn production (<i>Zea mays</i>)

An experiment with increasing rates of fertilizer and manure in silage corn was established to evaluate the agronomic crop response and to estimate the manure nitrogen availability. The treatments were designed to deliver 0, 67, 100 and 133% of the crop nitrogen requirements (CNR), using ammonium sulphate and manure as N source. Dry matter (DM) yield was similar among treatments receiving N, but those values were greater than those found in the control. Nitrogen extraction at harvest was not statistically different in treatments with fertilizer or manure, but it was higher in these treatments than in the control without N (p≤ 0.05). With both sources of N, crop N extraction was adjusted to a quadratic regression equation, as a function of N rates. According to the fertilizer equivalence (EF) methodology, the rate of 231.3 kg/ha of inorganic fertilizer N, and 752.9 kg/ha of total N in manure, had 129.5 kg/ha of N extracted by the crop. The ratio of the above rates, fertilizer N/ manure total N, represents the crop available manure N; in the present study, it was 30.7% of total N in the manure. Since no differences in yield were observed between N sources, it is concluded that N fertilizer can be substituted by manure, at a rate estimated to provide the crop N requirements. The estimation of the manure available N is important to adjust manure rates, thereafter avoiding excessive applications and pollution risks.     

Clubroot resistance QTL are modulated by nitrogen input in <Emphasis Type="Italic">Brassica napus</Emphasis>

Key message

Nitrogen levels can modulate the effectiveness of clubroot resistance in an isolate- and host-specific manner. While the same QTL were detected under high and low nitrogen, their effects were altered.

Abstract

Clubroot, caused by Plasmodiophora brassicae, is one of the most damaging diseases of oilseed rape and is known to be affected by nitrogen fertilization. However, the genetic factors involved in clubroot resistance have not been characterized under nitrogen-limiting conditions. This study aimed to assess the variability of clubroot resistance under different nitrogen levels and to characterize the impact of nitrogen supply on genetic resistance factors. Linkage analyses and a genome-wide association study were conducted to detect QTL for clubroot resistance and evaluate their sensitivity to nitrogen. The clubroot response of a set of 92 diverse oilseed rape accessions and 108 lines derived from a cross between ‘Darmor-bzh’ (resistant) and ‘Yudal’ (susceptible) was studied in the greenhouse under high- and low-nitrogen conditions, following inoculation with the P. brassicae isolates eH and K92-16. Resistance to each isolate was controlled by a major QTL and a few small-effects QTL. While the same QTL were detected under both high and low nitrogen, their effects were altered. Clubroot resistance to isolate eH, but not K92-16, was greater under a low-N supply versus a high-N supply. New sources of resistance were found among the oilseed rape accessions under both low and high-N conditions. The results are discussed relative to the literature and from a crop improvement perspective.