Age determination of sediment cores off western Spitsbergen

The Late Weichselian glacial history of the continental shelf off western Spitsbergen is discussed, based on acoustic sub-bottom records and sediment cores. The outer part of Isfjorden and the inner shelf to the west of this fjord are characterized by a thin veneer (10-20 m) of glacigenic sediments and absence of ice-marginal features. Towards the outer shelf the sediment thickness increases significantly, and exceeds 500 m at the shelf edge. Possible moraine complexes were identified in this outer part. Sediment cores from the inner shelf sampled a firm diamicton, interpreted as till, beneath soft glaciomarine sediments. Radiocarbon dates on shells from the clay resting directly on the till, suggest an age of around 12,500 yrs B.P. for the base of the marine sequence. We argue that grounded ice covered the sites shortly before. In contrast to suggestions that the fjords and coast were partly ice free during the Late Weischselian, we conclude that the ice must have reached out onto the continental shelf.

Age determination of sediment cores from the western Svalbard margin

The deglaciation of the continental shelf to the west of Spitsbergen and the main fjord, Isfjorden, is discussed based on sub-bottom seismic records and sediment cores. The sea floor on the shelf to the west of Isfjorden is underlain by less than 2 m of glaciomarine sediments over a firm diamicton interpreted as till. In central Isfjorden up to 10 m of deglaciation sediments were recorded, whereas in cores from the innermost tributary, Billefjorden, less than a meter of ice proximal sediments was recognized between the till and the 'normal' Holocene marine sediments. We conclude that the Barents Sea Ice Sheet terminated along the shelf break during the Late Weichselian glacial maximum. Radiocarbon dates from the glaciomarine sediments above the till indicate a stepwise deglaciation. Apparently the ice front retreated from the outermost shelf around 14.8 ka. A dramatic increase in the flux of line-grained glaciomarine sediments around 13 ka is assumed to reflect increased melting and/or current activity due to a climatic warming. This second stage of deglaciation was interrupted by a glacial readvance culminating on the mid-shelf area shortly after 12.4 ka. The glacial readvance, which is correlated with a simultaneous readvance of the Fennoscandian ice sheet along the western coast of Norway, is attributed to the so-called 'Older Dryas' cooling event in the North Atlantic region. Following this glacial readvance the outer part of Isfjorden became rapidly deglaciated around 12.3 ka. During the Younger Dryas the inner fjord branches were occupied by large outlet glaciers and possibly the ice front terminated far out in the main fjord. The remnants of the Barents Sea Ice Sheet melted quickly away as a response to the Holocene warming around 10 ka.

Age determination of sediments off western Svalbard

Late Quaternary sediment yields from the Isfjorden drainage area (7327 km**2), a high arctic region on Svalbard characterized by an alpine landscape, have been reconstructed by using seismic stratigraphy supported by sediment core analysis. The sediments that accumulated in the fjord during and since deglaciation can be divided into three stratigraphic units. The volumes of these units were determined and converted into sediment yield rates averaged over the drainage basin. During deglaciation, 13 to 10 ka, the sediment yield was ~860 tons(t)/km**2/yr. In the early Holocene it decreased to 190 t/km**2/yr, and then increased to 390t/km**2/yr during the late Holocene Little Ice Age. When normalized to the approximate glacierized area, these rates correspond to a sediment yield of ~800 t/km**2/yr . Sediment yield from non-glacierized parts of the drainage is estimated to be 35 t/km**2/yr. At times when ice advanced to the shelf edge, sediment was scoured from the fjord and deposited on the outer shelf and in a well-defined deep sea fan. Between 200 ka and 13 ka, 328 km**3 of sediment accumulated here, corresponding to a mean sediment yield rate of 335 t/km**2/yr. This is broadly consistent with calculations based on the above rates of sediment yield in glacierized and non-glacierized areas, and on estimates, based on glacial geology, of the temporal variation in degree of glacierization over the past 200 kyr. These figures indicate that much of the glacigenic sediment on the shelf and slope was eroded from the uplands of Svalbard by small glaciers during interstadials and interglacials. The sediments were temporarily stored in the fjord prior to redeposition on the shelf and slope during ice sheet advance. Taken into consideration, such redisposition of pre-eroded material will reduce estimates of primary ice sheet erosion rate.

栉孔扇贝和海湾扇贝免疫防御特性的比较研究

贝类养殖作为我国传统的海水养殖产业，在我国沿海地区的经济发展中起重要作用。但由于近年来养殖扇贝病害的不断发生，不仅造成了巨大的经济损失，而且直接威胁到现有养殖产业的生存和发展。目前认为，机体抗病能力的下降是发生流行性死亡的主要原因之一。因此，深入研究扇贝免疫防御特性，能更好地了解和解决贝类养殖中的病害问题。本文比较了健康状态和重金属污染以及高温胁迫下海湾扇贝和栉孔扇贝部分免疫指标的变化，并对同龄不同大小的栉孔扇贝的部分免疫指标进行了比较，以期更好的了解贝类的防御机制，为扇贝病害防治提供资料。研究结果如下: 用流式细胞仪技术对血细胞死亡率、细胞吞噬率和呼吸爆发进行了测定，发现健康状态下两种扇贝的细胞死亡率相差不大，海湾扇贝为4.83%，栉孔扇贝为4.95%；细胞吞噬率差异显著(P<0.05)，海湾扇贝为26.73%，栉孔扇贝为19.89%；呼吸爆发的基础值相差也不大，海湾扇贝为1.94，栉孔扇贝为1.56。另外用免疫化学方法对健康状态下栉孔扇贝和海湾扇贝血淋巴和肝胰腺中SOD、ACP活性和MDA含量也进行了测定与比较。发现在血淋巴和肝胰腺中，两种扇贝SOD活性均存在显著差异(P<0.05)，其中海湾扇贝分别为995.43和113.99，栉孔扇贝分别为446.64和40.6；血淋巴和肝胰腺中ACP活性差异显著(P<0.05)，海湾扇贝分别为90.19和432.36，栉孔扇贝分别为73.26和146.63；血淋巴中和肝胰腺中MDA含量差异不显著(P>0.05)，海湾扇贝分别为3.37和92.46，栉孔扇贝分别为2.17和28.96。实验结果说明，海湾扇贝对细菌等异物的吞噬和杀灭能力以及机体自身的抗氧化能力高于栉孔扇贝，这为海湾扇贝比栉孔扇贝具有更高的抗逆性提供了证据。 用相同的方法对不同浓度(0, 0.2, 0.3, 0.5 mg L-1) Pb2+溶液浸泡后的栉孔扇贝和海湾扇贝的血细胞死亡率、细胞吞噬率和呼吸爆发进行了检测，同时测定了Pb2+处理后肝胰腺中SOD、ACP活性和MDA含量的变化。结果表明，栉孔扇贝的血细胞死亡率与对照组相比有上升趋势，且随着Pb2+浓度的增加而显著增加，而海湾扇贝在相同条件Pb2+的胁迫下，血细胞的死亡率明显低于栉孔扇贝。栉孔扇贝各实验组细胞吞噬率均低于对照组，而海湾扇贝在低浓度的Pb2+浸泡后，细胞的吞噬率与对照组相比有所降低，但随着浓度的继续增加，细胞的吞噬率反而上升，甚至略高于对照组。栉孔扇贝血细胞的呼吸爆发在Pb2+胁迫后较对照组有所升高，但随着浓度的增加，呼吸爆发有下降的趋势，而海湾扇贝的呼吸爆发随着Pb2+浓度的增加而显著增加。对两种扇贝体液免疫指标的测定发现，各实验组SOD的活性均比对照组高，且海湾扇贝的SOD活性高于栉孔扇贝；随着Pb2+浓度的增加，各实验组ACP的活性一直呈上升趋势，且海湾扇贝的ACP活性也高于栉孔扇贝；Pb2+处理后MDA的含量均显著增加，其中栉孔扇贝MDA含量的增幅明显高于海湾扇贝。该结果说明，Pb2+对两种扇贝的免疫系统都有一定的影响，但相同剂量的Pb2+对两种扇贝的毒害程度不同，海湾扇贝对Pb2+的耐受性似乎高于栉孔扇贝。 对海湾扇贝和栉孔扇贝的升温刺激实验发现，当养殖水体的温度从18℃缓慢升高到30℃后，栉孔扇贝在第三天开始出现大量死亡现象，而海湾扇贝未出现死亡。因而本文只对升温前后的海湾扇贝进行了细胞死亡率、吞噬率和呼吸爆发的测定和比较。结果发现，与升温前相比，血细胞的死亡率在温度升高后略有增加，但差异不显著(P>0.05)；而细胞吞噬率在温度升高后显著下降；通过对呼吸爆发积聚的活性氧（Reactive Oxygen Species，ROS）的测定发现，升温后血细胞的ROS含量显著高于升温前(P<0.05)。该结果表明，高温会影响血细胞的功能，使机体的免疫防御能力下降，从而导致病害的发生。 另外，本文对同龄不同大小的栉孔扇贝的血细胞吞噬率以及血淋巴和肝胰腺中SOD、ACP活性和MDA含量进行了测定与比较。结果发现: 小扇贝的血细胞吞噬率略高于大扇贝，分别达到了22.82和20.96；在血淋巴及肝胰脏中，两组扇贝SOD酶的活性均差异显著(P<0.05)，小扇贝分别为613.88和102.01，大扇贝分别为356.15和50.22；血淋巴中小扇贝ACP的活性极显著的高于大扇贝(P<0.01)，分别为44.3和2.91，但肝胰腺中大扇贝和小扇贝ACP的活性相差不大，大扇贝为455.75，小扇贝为485.33；大扇贝和小扇贝血淋巴和肝胰脏中MDA含量相差不大，大扇贝分别为2.67和31.83，小扇贝分别为3.17和35.33。该结果说明，小扇贝对细菌等异物的吞噬和杀灭能力以及机体自身的抗氧化能力高于大扇贝，这为生长与抗逆性相颉抗提供了依据。

Reading skills. 'Habilidades de lectura'.

Unidad didáctica formada por textos y sus correspondientes actividades clasificadas en tres niveles (Beginner, Intermediate y Avanced). Contiene: utilización de estructuras lingüísticas fundamentales, estructuras y elementos formales así como las situaciones de comunicación escrita más habituales. Tiene como objetivos la comprensión y la expresión escritas, la valoración de los textos escritos como fuente de información y acceso a otras culturas y la valoración de la lengua extranjera como medio de comunicación con otras culturas.

Genetic parameters and relationships between growth traits and scrotal circumference measured at different ages in Nellore cattle

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Report.

Report year irregular.

Report.

Biennial report of the Dept. of Agriculture and Immigration,1948-49--1964-65

Natriuretic peptide-based screening and collaborative care for heart failure:the STOP-HF randomized trial

IMPORTANCE: Prevention strategies for heart failure are needed.

OBJECTIVE: To determine the efficacy of a screening program using brain-type natriuretic peptide (BNP) and collaborative care in an at-risk population in reducing newly diagnosed heart failure and prevalence of significant left ventricular (LV) systolic and/or diastolic dysfunction.

DESIGN, SETTING, AND PARTICIPANTS: The St Vincent's Screening to Prevent Heart Failure Study, a parallel-group randomized trial involving 1374 participants with cardiovascular risk factors (mean age, 64.8 [SD, 10.2] years) recruited from 39 primary care practices in Ireland between January 2005 and December 2009 and followed up until December 2011 (mean follow-up, 4.2 [SD, 1.2] years).

INTERVENTION: Patients were randomly assigned to receive usual primary care (control condition; n=677) or screening with BNP testing (n=697). Intervention-group participants with BNP levels of 50 pg/mL or higher underwent echocardiography and collaborative care between their primary care physician and specialist cardiovascular service.

MAIN OUTCOMES AND MEASURES: The primary end point was prevalence of asymptomatic LV dysfunction with or without newly diagnosed heart failure. Secondary end points included emergency hospitalization for arrhythmia, transient ischemic attack, stroke, myocardial infarction, peripheral or pulmonary thrombosis/embolus, or heart failure.

RESULTS: A total of 263 patients (41.6%) in the intervention group had at least 1 BNP reading of 50 pg/mL or higher. The intervention group underwent more cardiovascular investigations (control, 496 per 1000 patient-years vs intervention, 850 per 1000 patient-years; incidence rate ratio, 1.71; 95% CI, 1.61-1.83; P<.001) and received more renin-angiotensin-aldosterone system-based therapy at follow-up (control, 49.6%; intervention, 56.5%; P=.01). The primary end point of LV dysfunction with or without heart failure was met in 59 (8.7%) of 677 in the control group and 37 (5.3%) of 697 in the intervention group (odds ratio [OR], 0.55; 95% CI, 0.37-0.82; P = .003). Asymptomatic LV dysfunction was found in 45 (6.6%) of 677 control-group patients and 30 (4.3%) of 697 intervention-group patients (OR, 0.57; 95% CI, 0.37-0.88; P = .01). Heart failure occurred in 14 (2.1%) of 677 control-group patients and 7 (1.0%) of 697 intervention-group patients (OR, 0.48; 95% CI, 0.20-1.20; P = .12). The incidence rates of emergency hospitalization for major cardiovascular events were 40.4 per 1000 patient-years in the control group vs 22.3 per 1000 patient-years in the intervention group (incidence rate ratio, 0.60; 95% CI, 0.45-0.81; P = .002).

CONCLUSION AND RELEVANCE: Among patients at risk of heart failure, BNP-based screening and collaborative care reduced the combined rates of LV systolic dysfunction, diastolic dysfunction, and heart failure.

TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00921960.

Desechos líquidos: el caso de las salas de belleza

El objetivo principal de este estudio preliminar consistió en el análisis de las fortalezas y las debilidades en el manejo de desechos líquidos en cinco salas de belleza para apoyar estudios posteriores. Adicionalmente, se realizó un muestreo de aguas residuales en dos de los salones de belleza, S1 y S2, en los que se recolectaron muestras compuestas durante un día laboral. Los valores promedio de pH, amonio, DQO y grasas y aceites superaron los límites permitidos en la legislación costarricense, estos fueron respectivamente: 7,96 ± 0,01; 0,38 ± 0,01 mg N/L; 77 ± 13 mg O2/L y 1905,0 ± 0,1 mg/L, para S1 y 8,88 ± 0,01, 57,4 ±0,2 mg N/L; 240 ± 128 mg O2/L y 2775,0 ± 0,1 mg/L, para S2. Se evidenció que la calidad del agua y el cumplimiento de la normativa vigente son dependientes del tipo de productos utilizados (biodegradables o no, con o sin amoniaco). Aunque los volúmenes de vertido son intermitentes y pequeños, estos desechos pueden impactar negativamenteel ambiente.