Age determinaton and age model of sediments from the Bay of Biscay

Continuous high-resolution mass accumulation rates (MAR) and X-ray fluorescence (XRF) measurements from marine sediment records in the Bay of Biscay (NE Atlantic) have allowed the determination of the timing and the amplitude of the 'Fleuve Manche' (Channel River) discharges during glacial stages MIS 10, MIS 8, MIS 6 and MIS 4-2. These results have yielded detailed insight into the Middle and Late Pleistocene glaciations in Europe and the drainage network of the western and central European rivers over the last 350 kyr. This study provides clear evidence that the 'Fleuve Manche' connected the southern North Sea basin with the Bay of Biscay during each glacial period and reveals that 'Fleuve Manche' activity during the glaciations MIS 10 and MIS 8 was significantly less than during MIS 6 and MIS 2. We correlate the significant 'Fleuve Manche' activity, detected during MIS 6 and MIS 2, with the extensive Saalian (Drenthe Substage) and the Weichselian glaciations, respectively, confirming that the major Elsterian glaciation precedes the glacial MIS 10. In detail, massive 'Fleuve Manche' discharges occurred at ca 155 ka (mid-MIS 6) and during Termination I, while no significant discharges are found during Termination II. It is assumed that a substantial retreat of the European ice sheet at ca 155 kyr, followed by the formation of ice-free conditions between the British Isles and Scandinavia until Termination II, allowed meltwater to flow northwards through the North Sea basin during the second part of the MIS 6. We assume that this glacial pattern corresponds to the Warthe Substage glacial maximum, therefore indicating that the data presented here equates to the Drenthe and the Warthe glacial advances at ca 175-160 ka and ca 150-140 ka, respectively. Finally, the correlation of our records with ODP site 980 reveals that massive 'Fleuve Manche' discharges, related to partial or complete melting of the European ice masses, were synchronous with strong decreases in both the rate of deep-water formation and the strength of the Atlantic thermohaline circulation. 'Fleuve Manche' discharges over the last 350 kyr probably participated, with other meltwater sources, in the collapse of the thermohaline circulation by freshening the northern Atlantic surface water.

Integrated disease management of stem end rot of mango in the Southern Philippines

This research aimed to develop and evaluate pre- and postharvest management strategies to reduce stem end rot (SER) incidence and extend saleable life of 'Carabao' mango fruits in Southern Philippines. Preharvest management focused on the development and improvement of fungicide spray program, while postharvest management aimed to develop alternative interventions aside from hot water treatment (HWT). Field evaluation of systemic fungicides, namely azoxystrobin ( Amistar 25SC), tebuconazole ( Folicur 25WP), carbendazim ( Goldazim 500SC), difenoconazole ( Score 250SC) and azoxystrobin+difenoconazole ( Amistar Top), reduced blossom blight severity and improved fruit setting and retention, resulting in higher fruit yield but failed to sufficiently suppress SER incidence. Based on these findings, an improved fungicide spray program was developed taking into account the infection process of SER pathogens and fungicide resistance. Timely application of protectant (mancozeb) and systemic fungicides (azoxystrobin, carbendazim and difenoconazole) during the most critical stages of mango flower and fruit development ensured higher harvestable fruit yield and minimally lowered SER incidence. Control of SER was also achieved by employing postharvest treatment such as HWT (52-55°C for 10 min), which significantly prolonged the saleable life of mango fruits. However, extended hot water treatment (EHWT; 46°C pulp temperature for 15 min), rapid heat treatment (RHT; 59°C for 30-60 sec), fungicide dip and promising biological control agents failed to satisfactorily reduce SER and prolong saleable life. In contrast, the integration of the improved spray program as preharvest management practice, and postharvest treatments such as HWT and fungicide dips (azoxystrobin, 150-175 ppm; carbendazim, 312.5 ppm; and tebuconazole, 125-156 ppm), significantly reduced disease and extended marketable life for utmost 8 days.

An alkaline direct borohydride fuel cell with hydrogen peroxide as oxidant

A novel alkaline direct borohydride fuel cell (ADBFC) using varying concentrations of hydrogen peroxide as oxidant and sodium borohydride with sodium hydroxide, each of differing concentration, as fuel is reported. A peak power density of ca. 150 in W cm(-2) at a cell voltage of 540 mV can be achieved from the optimized ADBFC operating at 70 degrees C. (c) 2004 Elsevier B.V. All rights reserved.

An alkaline direct borohydride fuel cell with hydrogen peroxide as oxidant

A novel alkaline direct borohydride fuel cell (ADBFC) using varying concentrations of hydrogen peroxide as oxidant and sodium borohydride with sodium hydroxide, each of differing concentration, as fuel is reported. A peak power density of ca. 150 in W cm(-2) at a cell voltage of 540 mV can be achieved from the optimized ADBFC operating at 70 degrees C. (c) 2004 Elsevier B.V. All rights reserved.

Exposición y crítica de la ética de Clemente de Alejandría

Resumen: En este artículo, el autor expone la ética de san Clemente de Alejandría recurriendo principalmente a El Pedagogo y al Protréptico. Da especial importancia a conceptos como salvación, libre albedrío, consejo, imitación, entre otros. Después, el autor realiza una crítica buscando retomar algunas tesis que pueden mantener cierta vigencia para el planteamiento de una ética hodierna, buscando que esta última sea filosófica. Pero es importante tener presente que la ética por naturaleza recurre a la tradición, de la cual se alimenta para elaborar su reflexión filosófica. En otras palabras, la ética no parte desde el vacío, sino en el seno de una tradición, uno de cuyos representantes y constructores, en el contexto del mundo occidental, es Clemente de Alejandría.

热可交联聚酰亚胺/高性能热塑性树脂共混体系的研究

1．热可交联聚酰亚胺／高性能热塑性树脂共混体系的研究聚苯硫醚［Poly（phenylene sulfide），PPS］是由刚性结构的苯环和柔性的硫醚连接起来，交替排列构成的线性高分子化合物，具有高的热稳定性、良好的耐化学药品性、优良的电绝缘性、耐老化性和阻燃性等综合性能优异的高性能树脂。聚醚矾〔Poly（ether sulfone），PES］是一种非结晶性的热塑性工程塑料一，具有优异的热稳定性、耐高温蠕变性及优异的物理机械性能。其高的玻璃化转变温度（Tg=225℃），使其可以在较高温度下作为结构材料使用。本论文研究了PPS/PES二元共混物的热性能和动态力学性能，并以热可控交联的低分子量多官能单体PMR-POI（聚醚酰亚胺）为界面增强剂，分别研究了POI与PPS、PES之间的接枝和／或交联反应，POI对PPS结晶行为的影响，POI对PES分子运动的影响和POI对PPS/PES共混体系的界面增强。主要结果如下：1．PPS/PES共混物相容性的特征在于选择性的部分相容，少量的非晶PPS分子可以扩散进入PES相区，相反的扩散过程则不会发生。2．PPS/PES共混物的热学性质和动态力学性能主要受连续相的控制。3．PPS相的性能主要受其结晶度的影响，因此能够改变其结晶度的因素均会改变PPS相的性质。4．光谱学和流变的证据表明，POI同PES，PPs共混过程中有接枝反应发生，分子链增长，分子量加大。这种接枝和／或交联反应的程度是热可控的。5．POI是PPS的增塑剂，成核剂和扩链剂，与POI共混使得PPS结晶速率增加，平衡熔点上升，表面折叠自由能降低。6；在PES/POI体系中Pol对PEs起到了增塑的作用，Tg降低，经高温热处理后Tg上升。因此，POI对PES性能的影响也是热可控的。7．PMR-POI能够在PPS/PES共混体系中有效地扩散并起到了降低分散相粒子的尺寸、增强界面的作用。它是该共混体系的有效界面增强剂。8．"高温退火既能够提高扩散速率也能够提高反应速率；二者相互竞争。2．马来酸配封端溉碳酸丙撑酯的研究二氧化碳与环氧丙烷交替共聚物（polypropylene careonate，PPC）是由二氧化碳活化并与环氧丙烷共聚而成的一类可完全生物降解的新型高分子材料，具有巨大的潜在应用价值。本论文讨论了马来酸配封端的聚碳酸丙撑酯（MA-PPC）和未封端的PPC的粘弹性、流变行为以及热降解和热分解行为，并得出如下结论：1．马来酸配封端抑制了PPC解拉链式的热分解和无规链断裂热降解，PPC的热稳定性和力学性能得到提高。2．PPC和MA-PPC在玻璃化转变温度有相似的自由体积分数，PPC的Tg比MA-PPC稍低。虽然PPC和MA-PPC玻璃化转变表观活化能E。和平均松弛时间T随温度升高单调降低，但PPC的分子运动对温度更敏感，而MA-PPC较稳定。马来酸配封端改变了PPC分子运动的特征及松弛行为，许多实验证据证明，这是由于封端后的PPC大分子链间的相互作用增强及分子链缠结密度增加。3．MA-PPC在70℃左右会发生脱水，实现大分子偶联反应并得到变温红外光谱、分子量成倍增加及线膨胀数据的有力支持。4．用零剪切粘度几。的方法测得PPC及MA－PPC加工过程中的热降解温度，它们分别为150℃和175℃，在此温度以上，η0降低速率的增加归因于大分子的主链断裂以及解拉链反应。5．测得了PPC的临界缠结分子量，它几乎是MA-PPC相应值（6613）的3倍。这表明马来酸配封端不仅改善了PPC的熔体弹性，而且也大大增强了PPC的缠结密度以及分子链间的相互作用。6．在本实验条件下在氮气和空气的气氛中，MA-PPC同PPC的热降解和热分解行为几乎一致，即在PPc的加土过程可以忽略氧气对其的影响。7．虽然MA-PPC的玻璃化温度在40℃左右，但在40℃-120℃的温度区间内，MA-PPC达不到粘流状态。8．没有剪切力时在120℃-150℃，30分钟内，MA-PPC几乎没有降解，在静态条件下，低于170℃时，MA-PPC的解拉链式降解是十分轻微的，当温度超过170℃，PPC降解相当严重。9．在热机械力存在的情况下，发生无规断链的机会增加，无规断链又会加速解拉链降解，因此实际加工中的加工窗口比静态下窄，MIA-PPC的加工窗口应为130℃-160℃。10．MA-PPC的热分解过程是一步完成的，热分解温度随升温速率的加快而提高，并计算出热分解的表观活化能为623.3KJ／mol。

中国对虾育种方法研究与遗传连锁图谱的构建

本研究以中国对虾为材料，以杂交育种和选择育种为目标，进行了系统的中国对虾杂交育种试验、生长性状遗传参数试验及其分子遗传连锁图谱的构建工作。结果表明以不同地理群体杂交作为基础群体，然后采用系统的选择育种方法可以获得较好的选择效果。构建的遗传连锁图谱为中国对虾分子辅助育种提供一定的基础。这些试验结果为中国对虾合理系统的育种工作提供了理论基础和数据支持。其具体结果如下： 1. 试验对中国对虾黄渤海水域乳山湾群体（WYP）和朝鲜半岛南海群体（WKN）的2个群体及其杂交后代不同月龄生长情况和存活率进行了研究，测量体长（TL）、头胸甲长（CL）、头胸甲宽（CW）、第2、3腹节高（HST）、第2、3腹节宽（WST）、体重（BW）和存活率共7个性状，计算各项指标的杂种优势率，并对各性状进行了方差分析和多重比较。其3月龄生长情况和存活率研究结果表明，存活率在乳山湾群体（WYP♀）× 朝鲜半岛南海群体（WKN♂）杂交后代出现杂种劣势外，其他指标都表现出不同程度的杂种优势(4.37%～23.96% )。除了存活率外，杂交后代生长性状均显著高于亲本，乳山湾群体（WYP♀）×朝鲜半岛南海群体（WKN♂）杂交后代高于朝鲜半岛南海群体（WKN♀）× 乳山湾群体（WYP♂）杂交后代，黄渤海水域乳山湾群体高于朝鲜半岛南海群体后代。为确定测量性状与中国对虾体重的相关程度，建立了用体长(X1)，头胸甲宽(X2)，第2、3腹节宽(X3)，头胸甲长(X4)，第2、3腹节高(X5)估计体重的多元回归方程：Y = －2.056 + 0.03X1 + 0.076X2 + 0.078X3 + 0.033X4 + 0.043X5。 2. 中国对虾黄渤海水域乳山湾群体（WYP）和朝鲜半岛南海群体（WKN）2个群体及其杂交后代在4月龄时期的6个生长指标和存活率的杂种优势范围在0.514%到14.95%之间，WYP♀×WKN♂杂交后代在这7个指标中都高于WKN♀×WYP♂杂交后代。5月龄杂交后代也表现出一定程度的杂种优势，其范围在-9.000%～19.090%之间，但头胸甲长、第2、3腹节处高和存活率3个指标出现杂种劣势。不同杂交组合各个阶段生长发育情况和存活率在杂种优势表现出一定的规律。随着月龄的增加，WKN♀×WYP♂杂交后代杂种优势率有所增加，而WYP♀×WKN♂杂交后代的却有所降低。ANOVA分析结果表明，杂交后代在存活率方面与双亲差异不显著。4月龄的分析结果发现杂交后代在WST和BW这2个指标上存在显著差异。LSD多重比较结果显示，WYP♀×WKN♂杂交后代在BW指标上与亲本存在显著差异，在WST指标方面与其他3个组合的后代差异显著。5月龄的数据分析结果发现，杂交后代除体重存在显著差异外，其他各项指标差异均不显著。LSD多重比较结果发现，WKN♀×WYP♂杂交后代体重与其亲本WKN存在显著差异。 3. 对2个野生群体——朝鲜半岛南海岸群体（WKN）和黄渤海群体（WYP）和3个养殖群体——朝鲜半岛群体的养殖一代（FKN），黄海1号（HH1）和即抗98（JK98）进行杂交试验的研究，结果表明JK98 (♀)  WKN (♂)组合在存活率方面最高，其余的依次为WYP (♀) WKN (♂)，WKN (♀) WYP (♂)，FKN (♀)HH1 (♂) 和 WYP (♀) FKN (♂)。而在体重方面FKN(♀)  HH1(♂)组合最高，其余的依次为WKN (♀) WYP (♂)，WYP (♀) WKN (♂)，WYP (♀)FKN (♂) 和 JK98 (♀)WKN (♂)。在所有生长性状方面，JK98 (♀)  WKN (♂)在5个组合中是最低的。方差检测结果表明，TL、CL、HST、LL和BW这5个指标在不同组合间存在差异，而其他指标不存在差异。多重比较结果发现JK98 (♀)WKN (♂)组合的TL与其他组合间差异极显著，HST指标与WKN (♀) WYP (♂)，FKN(♀)  HH1(♂)和 WYP (♀)  WKN (♂)这3个组合差异显著，BW指标与WKN (♀) WYP (♂) 和 FKN(♀)  HH1(♂)差异显著。 4. 通过人工授精的方法建立了中国对虾21个半同胞家系，测量了中国对虾21个半同胞（46个全同胞）家系的TL、CL、CW、HST、WST、第1腹节长（FL���、第6腹节长（LL）。利用MTDFREML软件得到生长性状遗传力在0.15~0.35之间，属于中度遗传力范围。TL的遗传力为0.34±0.071，CL的为0.30±0.070，CW为0.35±0.077，WST为0.33±0.073，HST为0.33±0.073，FL���最低为0.15±0.044，LL的为0.24±0.059。各个性状间表现出高的正相关，其中CW和TL以及HST的遗传相关最大，FL���WST的遗传相关最小。 通过以上杂交育种和选择育种的研究，认为单纯的依靠杂交育种来改善中国对虾的育种工作可能具有一定的局限性。所以在实际的育种过程中，以中国对虾不同群体的杂交后代作为基础群体，并以此为基础进行系统的选择育种应该具有更大的潜力。 5. 本试验利用中国对虾F2群体和AFLP分子标记技术进行了遗传连锁图谱的构建。利用55对AFLP引物组合对F2家系的110个个体进行了研究，结果检测到532个符合作图策略的AFLP标记。利用卡方检验检测分离位点是否符合孟德尔分离定律。对于符合3：1比例的分离位点利用F2自交模型构建性别平均连锁图谱，对于符合1：1比例的分离位点利用拟测交理论分别构建中国对虾的雌性和雄性遗传连锁图谱。雌性、雄性和性别平均遗传图谱分别有28、35和44个连锁群，图谱实际长度分别为1090、1617和1772.1 cM。中国对虾遗传连锁图谱估计基因组长度为2420 cM，符合与人类基因组相比的对虾类基因组长度。中国对虾雄性遗传连锁图谱比雌性遗传连锁图谱长32.6%，这可能说明中国对虾不同性别存在不同的重组率。通过皮尔逊相关系数检测认为AFLP标记在中国对虾图谱上分布均匀。本文利用AFLP标记构建的中国对虾遗传连锁图谱为中国对虾基因组研究和遗传改良提供一定的基础，同时也应该开发微卫星等共显性标记，为遗传连锁图谱的整合提供条件。

ZnO based nanowires grown by chemical vapour deposition for selective hydrogenation of acetylene alcohols

Vertically aligned ZnO nanowires (NWs) with a length of 1.5-10 mu m and a mean diameter of ca. 150 nm were grown by chemical vapour deposition onto a c-oriented ZnO seed layer which was deposited by atomic layer deposition on Si substrates. The substrates were then spin-coated with an ethanol solution containing Pd nanoparticles with an average size of 2.7 and 4.5 nm. A homogeneous distribution of the Pd nanoparticles on ZnO NWs has been obtained using both Pd particle series. The catalytic activity of the ZnO NWs and Pd/ZnO NWs catalysts was measured in the semihydrogenation of 2-methyl-3-butyn-2-ol at 303-343 K and a pressure of 2-10 bar. The effect of the solvent used on the catalytic performance of the Pd/ZnO NWs catalyst was studied. The Pd/ZnO catalysts showed alkene selectivity of up to 95% at an alkyne conversion of 99%. A kinetic model is proposed to explain the activity and selectivity of the ZnO support and Pd/ZnO catalysts.

Revision of the genus Fosterella (Bromeliaceae)

Die vorliegende Arbeit stellt eine umfassende taxonomische Revision der Gattung Fosterella L.B. Sm. (Bromeliaceae) dar, die alle 31 derzeit akzeptierten Arten umfasst und einen Bestimmungsschlüssel für diese beinhaltet. Die Revision beruht auf der morphologisch-anatomischen Auswertung von Herbarmaterial (über 800 Exsikkate), Lebendpflanzen (ca. 150 Akzessionen) und eigenen vergleichenden Untersuchungen im Freiland. Die Gattung Fosterella ist seit nunmehr etlichen Jahren Forschungsgegenstand einer interdisziplinären Studie, die sowohl molekulrae, als auch anatomische, morphologische und biogeographische Untersuchungen einbezieht. Unser Interesse an der Gattung Fosterella gründet sich auf ihrer enormen ökologischen und biogeographischen Vielfalt, sie gilt als hervorragendes Modellsystem für Artbildungsmechanismen in den Anden. In den letzten Jahren wurde von verschiedenen molekularen Methoden Gebrauch gemacht, um die verwandtschaftlichen Beziehungen innerhalb der Gattung zu untersuchen, so dass mittlerweile gut aufgelöste Stammbäume vorliegen. Diese molekularen Studien, überwiegend durchgeführt von Dr. Martina Rex, wurden ergänzt durch intensive Sammelaktivitäten und eingehende taxonomische Untersuchungen im Rahmen der vorliegenden Revision. Auf diese Weise konnten die morphologische Plastizität der einzelnen Arten erfasst und schließlich ein wohlfundiertes Artkonzept vorgelegt werden. Zunächst wird ein kurzer Überblick über die Familie der Bromeliaceen als auch die Gattung Fosterella gegeben, in dem jeweils Informationen zur Verbreitung, Morphologie, Physiologie, Ökologie und Phylogenie geliefert werden. Im Anschluss an einen historischen Überblick des taxonomischen Werdegangs wird die Abgrenzung der Gattung Fosterella zu den nächstverwandten Gattungen Deuterocohnia, Dyckia und Encholirium erläutert. Die morphologischen Merkmale zur Differenzierung der Arten innerhalb der Gattung werden im Hinblick auf ihre Zuverlässigkeit und ihr Gewicht diskutiert. Der Artschlüssel basiert auf Merkmalen, die leicht auszumachen und gut zu unterscheiden sind. Bei der ausführlichen Beschreibung der Arten wird auch auf ihre jeweilige Verbreitung, Ökologie, taxonomische Abgrenzung, systematische Verwandtschaft sowie die Etymologie des Namens eingegangen. Beigefügt sind jeweils Zeichnungen, ein Foto vom Holo-/Lectotypus, Fotos von Lebendpflanzen sowie eine Verbreitungskarte. Im Rahmen der taxonomischen Arbeit wurden fünf Arten zu Synonymen reduziert: Fosterella chiquitana Ibisch, R. Vásquez & E. Gross und F. latifolia Ibisch, R. Vásquez & E. Gross wurden in die Synonymie von F. penduliflora (C.H. Wright) L.B. Sm. eingezogen; F. fuentesii Ibisch, R. Vásquez & E. Gross als Synonym zu F. albicans (Griseb.) L.B. Sm. gestellt; F. elata H. Luther in die Synonymie von F. rusbyi (Mez) L.B. Sm. verwiesen und F. nowickii Ibisch, R. Vásquez & E. Gross als Synonym zu F. weddelliana (Brongn. ex Baker) L.B. Sm. gestellt. Fosterella schidosperma (Baker) L.B. Sm. var. vestita L.B. Sm. & Read wird zum Synonym von Fosterella weberbaueri (Mez) L.B. Sm. reduziert. Sechs Arten wurden neu beschrieben: Fosterella batistana Ibisch, Leme & J. Peters; F. christophii Ibisch, R. Vásquez & J. Peters; F. elviragrossiae Ibisch, R. Vásquez & J. Peters; F. kroemeri Ibisch, R. Vásquez & J. Peters; F. nicoliana J. Peters & Ibisch und F. robertreadii Ibisch & J. Peters. Das Taxon F. gracilis (Rusby) L.B. Sm. wurde neu etabliert. Um die Evolution von einzelnen morphologischen Merkmalen zu rekonstruieren, wurden die Zustände von zehn ausgewählten Merkmalen kodiert und auf einen molekularen Stammbaum kartiert. Die folgenden Merkmalszustände wurden als ursprünglich innerhalb der Gattung ermittelt: Stammlosigkeit, ganzrandige Blattspreiten, flache Rosetten mit dem Boden aufliegenden Blättern, locker beschuppte Blattunterseiten, schildförmige Haare mit gezähntem Rand, ganzrandige Pedunkel-Brakteen, rispenförmiger Blütenstand, kahle/verkahlende Blütenstandsachsen, weiße Petalen und einfach-aufrechte Narben. Rückschlüsse bezüglich der Evolution und Ausbreitung der Gattung Fosterella werden diskutiert: Die überwiegend kleinen Verbreitungsgebiete der Arten hängen offensichtlich mit ihren fragmentierten, inselartigen Habitaten (z.B. innerandine Trockentäler) zusammen. Die Tatsache, dass die Yungas-Bergregenwälder des Departamento La Paz, Bolivia, die Region mit der größten Artenvielfalt darstellen, lässt sich mit der extrem variablen Topographie und der außerordentlich hohen Vielfalt an Habitaten dieser Region erklären. Aus folgenden Gründen erscheint es sehr wahrscheinlich, dass die Gattung Fosterella ihren Ursprung im Tiefland hat: Die Mehrheit der Arten weist einen eher mesophytischen Habitus auf und ist in mehr oder weniger humiden Habitaten zu finden. Die Gattung ist durch mehrere Arten in sehr alten Habitaten des präkambrischen Schilds im Tiefland von Zentral-Südamerika vertreten. Weiterhin betreiben, soweit bekannt, alle Fosterella Arten C3 Photosynthese, während in den Gattungen der Schwestergruppe, Deuterocohnia, Dyckia and Encholirium, CAM der verbreitete Photosyntheseweg ist. In jedem Fall ist die Besiedelung der Anden und/oder Tieflandhabitate mehrfach unabhängig voneinander geschehen, vielleicht sogar in beiden Richtungen.

Subglacial bedform evidence for a major palaeo-ice stream and its retreat phases in Amundsen Gulf, Canadian Arctic Archipelago

Ascertaining the location of palaeo-ice streams is crucial in order to produce accurate reconstructions of palaeo-ice sheets and examine interactions with the ocean-climate system. This paper reports evidence for a major ice stream in Amundsen Gulf, Canadian Arctic Archipelago. Mapping from satellite imagery (Landsat ETM+) and digital elevation models, including bathymetric data, is used to reconstruct flow-patterns on southwestern Victoria Island and the adjacent mainland (Nunavut and Northwest Territories). Several flow-sets indicative of ice streaming are found feeding into the marine trough and cross-cutting relationships between these flow-sets (and utilising previously published radiocarbon dates) reveal several phases of ice stream activity centred in Amundsen Gulf and Dolphin and Union Strait. A large erosional footprint on the continental shelf indicates that the ice stream (ca. 1000 km long and ca. 150 km wide) filled Amundsen Gulf, probably at the Last Glacial Maximum. Subsequent to this, the ice stream reorganised as the margin retreated back along the marine trough, eventually splitting into two separate low-gradient lobes in Prince Albert Sound and Dolphin and Union Strait. The location of this major ice stream holds important implications for ice sheet-ocean interactions and specifically, the development of Arctic Ocean ice shelves and the delivery of icebergs into the western Arctic Ocean during the late Pleistocene. Copyright (C) 2006 John Wiley & Sons, Ltd.

Influence of package, type of apple juice and temperature on the production of patulin by Byssochlamys nivea and Byssochlamys fulva

Although the production of patulin in apple fruits is mainly by Penicillium expansum, there is no information on the ability of heat resistant moulds that may survive pasteurization to produce this mycotoxin in juice packages during storage and distribution. In this study, the production of patulin by Byssochlamys spp (Byssochlamys nivea FRR 4421, B. nivea ATCC 24008 and Byssochlamys fulva IOC 4518) in cloudy and clarified apple juices packaged in laminated paperboard packages or in polyethylene terephthalate bottles (PET) and stored at both 21 degrees C and 30 degrees C, was investigated. The three Byssochlamys strains were able to produce patulin in both cloudy and clarified apple juices. Overall, the lower the storage temperature, the lower the patulin levels and mycelium dry weight in the apple juices (p<0.05). The greatest variations in pH and degrees Brix were observed in the juices from which the greatest mycelium dry weights were recovered. The maximum levels of patulin recovered from the juices were ca. 150 mu g/kg at 21 degrees C and 220 mu g/kg at 30 degrees C. HPLC-UV, HPCL-DAD and mass spectrometry analyses confirmed the ability of B. fulva IOC 4518 to produce patulin. Due to the heat resistance of B. nivea and B. fulva and their ability to produce patulin either in PET bottles or in laminated paperboard packages, the control of contamination and the incidence of these fungi should be a matter of concern for food safety. Control measures taken by juice industries must also focus on controlling the ascospores of heat resistant moulds. (C) 2010 Elsevier B.V. All rights reserved.

Effect of Calcium Pre-rinse and Fluoride Dentifrice on Enamel and on Dental Plaque Formed In Situ

Purpose: The aim of this in situ double-blind randomised crossover study was to investigate the effect of calcium (Ca) pre-rinse on the composition of plaque and on enamel prior to the use of fluoride (F) dentifrice. Materials and Methods: During four phases (14 days each) of this study, 10 volunteers had agreed to wear dental appliances containing two healthy bovine enamel blocks. A fresh solution containing 20% weight/volume (w/v) sucrose was dripped on the enamel blocks ex vivo for 5 min three times a day. Subsequently, the appliances were replaced in the mouth, and the volunteers rinsed their mouth with 10 mL of a Ca (150 mmol/L) or a placebo rinse (1 min). In sequence, a slurry (1:3 w/v) of F (1030 ppm) or placebo dentifrice was dripped onto the blocks ex vivo for 1 min. During this time, the volunteers brushed their teeth with the respective dentifrice. The appliances were replaced in the mouth, and the volunteers rinsed their mouth with water. The plaque formed on the blocks was analysed for F and Ca. The enamel demineralisation as well as the incorporation of F on enamel was evaluated by cross-sectional microhardness and alkali-soluble F analysis, respectively. Data were tested using analysis of variance (P < 0.05). Results: The Ca pre-rinse prior to the use of the F dentifrice led to a three- and sixfold increase in the plaque F and Ca concentrations, respectively. It also did not have any additive effect on the F content on the enamel and the demineralisation of the enamel, in comparison with the use of F dentifrice alone. Conclusions: A Ca lactate rinse used prior to the F dentifrice was able to change the mineral content in the plaque, but it was unable to prevent enamel demineralisation.

Efeito da densidade de tubérculos de tiririca (Cyperus rotundus) sobre o crescimento inicial de plantas de algodão

O objetivo deste trabalho foi avaliar a interferência de densidades de tubérculos de tiririca no crescimento inicial de plantas de algodão, cultivar Delta Opal. Para isso, utilizaram-se caixas de cimento-amianto (0,60 x 0,60 x 0,25 m) com Latossolo Vermelho Escuro, no centro das quais foram semeadas seis sementes de algodão, em linha, espaçadas de 0,10 m; em seguida, plantaram-se tubérculos de tiririca nas densidades de 0, 5, 10, 15, 25, 50, 75, 100, 125, 150, 175 e 200 tubérculos por caixa, que foram nestas distribuídos aleatoriamente. O delineamento experimental foi o de blocos casualizados, em quatro repetições. Aos 50 dias após a semeadura, foram determinados, nas plantas de algodão, a altura e o teor relativo de clorofila total. Ao término do período experimental (65 dias após a emergência do algodão), foram determinados: altura, teor relativo de clorofila total, área foliar e matéria seca do caule e das folhas. Nas plantas de tiririca foi feita a contagem do número final de plantas (partes aéreas) por caixa. A interferência da tiririca no crescimento inicial do algodoeiro iniciou-se a partir de 5 tubérculos/caixa, reduzindo em até 71% as características analisadas na mais alta densidade (200 tubérculos/caixa). A competição intra-específica na tiririca acentuou-se a partir de 75 tubérculos/caixa, quando obteve mais do que 1,86 brotação por tubérculo. As características avaliadas nas plantas de algodão mais sensíveis ao efeito dos tubérculos de tiririca foram: área foliar, massa seca de folhas, caule e altura das plantas, nesta ordem.

Seletividade do herbicida saflufenacil a Eucalyptus urograndis

As áreas com plantios florestais estão constantemente em expansão, e a interferência das plantas daninhas alteram o crescimento e desenvolvimento de plantas de eucalipto, pois estas competem por água, nutrientes, espaço e luz. Objetivou-se com este estudo avaliar a seletividade do herbicida saflufenacil, aplicado com e sem óleo mineral Dash, em plantas de Eucalyptus urograndis, em diferentes locais de aplica��ão (planta, solo e solo + planta). O delineamento experimental adotado foi o inteiramente casualizado, com quatro repetições, constituído de um fatorial 3 x 11, sendo três locais de aplica��ão do herbicida na planta e 11doses do herbicida saflufenacil combinadas ou não com o adjuvante Dash. Cada parcela constou de um vaso com uma planta. Os tratamentos usados foram: 0, 25, 25+Dash (0,5% v/v), 50, 50+Dash (0,5% v/v), 75, 100, 125, 150, 175 e 200 g i.a. ha-1 . Foram realizadas avaliações visuais de fitointoxica��ão durante 56 dias após aplica��ão (DAA). Avaliouse, ainda, a altura, o diâmetro de caule e a biomassa seca das plantas. Todas as doses testadas de saflufenacil sem adjuvante mostraram-se seletivas às plantas de E. urograndis, independentemente do local de aplica��ão. A adição de Dash aos tratamentos proporcionou injúrias severas às plantas nas avaliações iniciais, quando aplicado sobre as plantas, com a recuperação total destas no fim do ensaio, aos 56 DAA. A aplica��ão do herbicida em mistura com adjuvante somente no solo não causou intoxica��ão às plantas de eucalipto.