Hormone concentrations temporally associated with contralateral and ipsilateral relationships between the CL and preovulatory follicle during the third follicular wave in heifers

Concentrations of circulating hormones after Day 14 (Day 0 = ovulation) were determined daily in 87 interovulatory intervals (IOIs) in heifers. The IOIs were grouped into four permutations according to an ipsilateral (Ipsi) or contralateral (Contra) relationship between the CL and the preovulatory follicle and two (2W) or three (3W) follicular waves per IOI. The number of IOIs per group differed (P < 0.005) from equality among the Ipsi-2W (n = 27), Contra-2W (n = 31), Ipsi-3W (n = 9), and Contra-3W (n = 20) groups. A continuous decrease in progesterone (luteolysis) began later (P < 0.05) in the Contra-3W group (Day 18.0 ± 0.4) than in each of the Ipsi-2W (15.4 ± 0.2), Contra-2W (15.6 ± 0.2), and Ipsi-3W (16.2 ± 0.5) groups. Concentrations of LH and estradiol began to increase near the beginning of luteolysis in each group. A minor FSH surge that did not stimulate a major follicular wave developed in about 50% of the IOIs in each group, except that none were detected in the Ipsi-3W group. The minor FSH surge reached a peak about 4 days before ovulation and several days after wave 3 had emerged. The hypothesis that luteolysis begins earliest in two-wave IOIs, intermediate in three-wave IOIs with an ipsilateral CL/follicle relationship, and latest in three-wave IOIs with a contralateral relationship was supported. The hypothesis that a minor FSH surge occurs most frequently in association with three follicular waves was not supported.     

Characterising the fine sediment budget of a reach of the River Swale,Yorkshire, U.K. during the 1994 to 1995 winter season

Suspended sediment budget dynamics for a 55 km reach of the lowland River Swale, Yorkshire, U.K. are investigated for the period October 1994 to June 1995. Particular attention is paid to 11 storm events occurring between October 1994 and April 1995. Each of these storms produced significant suspended sediment transport. Variations in sediment dynamics, for example suspended sediment concentrations, hysteresis patterns and storm peak lag times through events and between the upstream and downstream ends of the reach are examined. Net sediment loss from the reach occurred during the extremely wet four month winter period from December 1994 to April 1995. Patterns of reach sediment storage are concluded to represent a combination of channel bed erosion and/or deposition, bank erosion and floodplain deposition. The implications of these patterns for sediment modelling are discussed.     

Ecosystem response to different management options in Marine Protected Areas (MPA): A case study of intertidal rocky shore communities

Marine Protected Areas (MPA) can be powerful coastal management tools with several specific goals, although there is debate concerning their effectiveness. There is no consensus regarding the ideal size of MPAs, and actually there is some evidence that perhaps size is not as critical as other specific factors in determining their success in terms of populations’ protection and ecological functions conservation. On the other hand, depending on the objectives, zones with different classification regimes in terms of rules and uses might enable the maintenance of the intended uses.At this light, we examined the case of the small (605 002 m²) rocky shore area of Avencas, near Lisbon, on the Atlantic western Coast of Portugal, which was classified as Biophysical Interest Zone (ZIBA) in 1998, due to its exceptional intertidal biodiversity, after what its protection status became controversial, leading to conflicts with the local population and incompliance with extant regulations. From 2010 efforts were carried out by local authorities to reclassify Avencas as Marine Protected Area, which was achieved in 2016.Monitoring intertidal communities in a MPA and adjacent areas is an effective and low-cost procedure to evaluate the evolution of the biodiversity of rocky shores. Therefore, antedating the creation of the new MPA, assessments of the ZIBA biodiversity were conducted from January 2013 to December 2015 on a monthly basis. This timeline was selected as a function of a change in visitors’ behavior induced from 2013 by several management and outreach initiatives, which increased in a certain extent the user’s compliance with regulations.A positive evolution was expected for density and/or species diversity of the different groups analysed (flora, sessile fauna and mobile fauna) in this three years period. However, a very strong storm occurred in 2014 produced a significant impact and changed large areas of the Avencas rocky shore. As a consequence, results did not display a recognizable recovery pattern of the intertidal communities, and following that extreme event are not even consistent with a hypothesized enhanced recovery capability of the ecosystem in a protected area. This suggests that longer data series are necessary to obtain more robust data regarding natural variability, since alterations caused by extreme events are always likely to occur. Additionally, results illustrate that indeed size matters because it influences the MPA openness, expressed as the ratio of periphery to area, and therefore its susceptibility to external driving forces. Such considerations must be taken into account in any management plan, which in this case should encompass an increase in the intertidal protected area, a new conditioned small-scale fishing regime, and an adequate monitoring programme to evaluate the effectiveness of the new management scheme.     

Intracellular pH change does not appear as a prerequisite for triggering activation of Barnea candida (Mollusca,Pelecypoda) oocytes

Barnea Candida oocytes, exposed to excess KCl, ammonia, or digitonin, exhibit germinal vesicle breakdown (GVBD) and reinitiate meiosis, at least up to first polar body extrusion. While we confirm that KCl—but not ammonia-induced activation requires external calcium, our findings that digitonin is effective at any pH from 6 to 8, in the presence of calcium, while the phorbol ester TPA and diacylglycerol fail to reinitiate meiosis, strongly suggests calcium as the main trigger for this process. Preliminary experiments using the fluorescent probes fluorescein diacetate and Quin 2/AM show, moreover, that KCl and ammonia produce both an intracellular calcium surge (30 nM) and a slight alkalinization of the intracellular cytoplasm from 7.84 to 8.05.     

老年原发性高血压患者血压晨峰与早期肾损害的临床观察

目的:探讨老年原发性高血压患者血压晨峰与早期肾损害的关系。方法:选择我院收治的94例老年原发性高血压患者进行24小时动态血压监测,并根据监测结果,将患者分为晨峰组62例和非晨峰组32例,检测和比较两组的血肌酐和尿素氮、12小时尿微量蛋白、尿β2微球蛋白、空腹血糖、血脂等指标。结果:老年高血压患者晨峰组12小时尿微量蛋白、尿β2微球蛋白均显著高于非晨峰组(P0.05);晨峰血压与12小时尿微量白蛋白(r=0.374)、尿β2微球蛋白(r=0.456)呈显著正相关。结论:老年原发性高血压患者血压晨峰与早期肾损害有关,治疗高血压的同时重视控制晨峰血压有重要意义。     

Sediment deposition patterns in Phragmites australiscommunities: Implications for coastal areas threatened by rising sea-level

The explosive expansion of the common reed Phragmites australisover the last 50 years in thewetlands of the U.S. mid-Atlantic has been of concernto biologists, resource managers and the generalpublic. The replacement of Spartinaspp.communities by the invasive P. australishasbeen widely reported, but the ecosystem effect of thisreplacement is poorly understood, especially withregard to sediment accretion processes and elevationchange. It is hypothesized that a more detailedunderstanding of individual plant species and theirrole in marsh accretion may provide an improvedability to predict the effect of projected sea-levelrise in coastal wetlands. Two coastal salt marsh siteson the Eastern Shore of Chesapeake Bay in Maryland(USA) were studied to quantify depositionalenvironments associated with P. australis.Short-term sediment deposition (24 hr) and stormdeposition (17 d) were measured using filter paperplates, and vertical accretion and elevation change (6mo.) were measured using a marker horizon coupled witha sedimentation erosion table (SET). Greater rates ofmineral and organic sediment trapping were associatedwith the P. australiscommunity in both asubsiding creek bank marsh (34 g·m^-2· day^-1in P. australisvs. 18 g·m^-2· day^-1in Spartinaspp.) and a laterally eroding marsh(24 g·m^-2· day^-1in P. australisvs.15 g·m^-2· day^-1in Spartinaspp.).Litter accumulation in P. australisstands isresponsible for the higher depositional patternobserved. Additionally, below ground accumulation inP. australiscommunities (as much as 3 mm in 6months) appears to substantially increase substrateelevation over relatively short time periods. ThusP. australismay provide resource managers witha strategy of combating sea-level rise and currentcontrol measures fail to take this intoconsideration.     

Major disturbances test resilience at a long‐term boreal forest monitoring site

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