Movement of yellowtail snapper (Ocyurus chrysurus Block 1790) and black grouper (Mycteroperca bonaci Poey 1860) in the northern Florida Keys National Marine Sanctuary as determined by acoustic telemetry

We tagged a total of 14 yellowtail snapper (Ocyurus chrysurus Bloch 1790) and black grouper (Mycteroperca bonaci Poey 1860) inside the Conch Reef Research Only Area (a no-take marine reserve) in the northern Florida Keys National Marine Sanctuary in November 2001. Both species are heavily exploited in the region. Our objective was to characterize site fidelity and movement behavior along the reef tract to the north and south of the release point. Fishes were collected by baited hook and line from the surface, surgically-tagged with coded-acoustic transmitters, and returned to the reef by snorkelers. Tracking of fish movement behavior was conducted by five acoustic receivers deployed on the seafloor from Davis Reef in the south to Pickles Reef in the north. Fishes were tracked for up to eight months. Results indicated that the majority of signal detections for individual fish from both species were recorded at the two Conch Reef receivers. Limited movement from Conch Reef to Davis Reef was recorded, but no signal detections were recorded at the two sites to the north of Conch Reef. These results suggest that both species show site fidelity to Conch Reef. Future studies will seek to characterize this site fidelity with increased temporal and spatial resolution at Conch Reef. (PDF contains 25 pages.)

Effects of suspended sediments on the development of eggs and larvae of striped bass and white perch

The possible ecological effects of suspended sediments are manifold. Briefly, suspended sediments may cause an increased surface for microorganism growth, fewer temperature fluctuations, chemical adsorption or absorption, blanketing, mechanical-abrasive actions, and light penetration reduction (Cairns, 1968). Sherk and Cronin (1970) have pointed out that the above effects have been little studied in the estuarine environment. The ecological effects of suspended sediments on fish eggs and larvae may be of prime importance t o the C and D Canal area, an important spawning and primary nursery area for a variety of estuary: e species (Johnson,1972). This section discusses the effects of suspended sediment on the eggs and larvae of striped bass and white perch.

Experimental design in fluvial ichthyology: getting the most for your money

In field biology, cost efficiency is an essential element of experimental design, with ramifications extending well beyond the basic monetary considerations associated with labour and equipment acquisition. Current economic constraints often require scientists to undertake many technical, secretarial and managerial tasks in addition to those associated with data collection, analysis, interpretation and publication. Because the time spent to process material in the laboratory can rarely be shortened without compromising the integrity of the results, it is imperative that field experiments be well-organised, addressing as many aspects of the problem as possible during the same sampling excursion. The sampling strategy employed should provide a maximum of good field data with a minimum cost of time and effort.

金属原卟啉的电化学聚合以及氧在其上的电催化还原

氧的电还原不仅在高效能量转换和储存装置中，而且在电解工业中降低电耗方面也起着重要的作用。为此寻求催化活性好、稳定性高和经济适用的氧还原催化剂是一个十分重要的课题。许多研究工作者已发现卟啉、酞菁一类过渡金属大环络合物对氧的催化还原有很高活性，但是其稳定性差。为提高催化剂的稳定性，人们进行了多种尝试，如真空沉积、热处理、将活性单体嵌入Nafion膜或导电高聚物膜中等，但都未能很好解决稳定性问题。我们试图将活性单体用电化学方法直接聚合在电极基底上，以提高催化剂的稳定性。为此，本论文主要进行了以下工作：（1）活性单体的合成，（2）钴原卟啉二甲酯(CoPP)的电化学聚合，以及（3）氧在聚CoPP膜上电还原的活性、稳定性和机理等的研究。一、通过实验摸索出一条由血红素单体合成CoPP单体的简便途径。二、研究了高聚物膜的电化学聚合和表征，以及膜在水溶液中的电化学行为。用循环伏安法(C.V.)和恒电位(P. S.)方法研究了CoPP单体直接聚合在不同的电极基底[如玻璃碳(GC)、烧结石墨(Pc)、导电玻璃和Pt等]上的条件。发现C.V.图上有三对氧化还原峰。在聚合的过程中，中断所旋加的电位时，聚合电量继续增加。找到了若干种能溶能聚CoPP膜的有机溶剂和水溶液，并对高聚物膜进行了红外、紫外表征，发现聚CoPP膜的紫外吸收红移不大，CoPP单体在聚合中，卟啉环上的一个乙烯基被饱和，卟啉环没有被破坏，在聚CoPP膜中，每个卟啉环中仍存在由四氦围绕着的中心金属。扫描电镜结果表明：高电位下聚合膜的空隙，比低电位下聚合膜的多，由此提出了阳离子自由基的聚合机理。此外我们还发现在酸性溶液中，能观察到明显的中心金属离子的氧化还原峰。三、氧在聚CoPP膜上电催化还原的研究 用RDE（旋转盘电极）方法比较了氧在聚CoPP/GC与吸附CoPP单体/GC上的电还原，发现聚CoPP膜的活性和稳定性都比吸附单体的高。聚合电位影响高聚物膜的稳定性。高聚物膜越厚，稳定性越好，并且随溶液pH值的降低而增大。高聚物膜厚度与其活性关系之间存在一个最佳值，低于或高于此值，其活性降低。在一定厚度范围内，氧电还原的Tafel斜率基本不变；其动力学反应常数(Kf)与电极表面上有效活性中心浓度(Pv')和乘积(Kf·Pv')随膜厚度的增加而降低。用RDE方法研究溶液pH值的影响时发现，在较宽的pH值范围内，聚CoPP/GC主要催化氧为二电子还原。聚CoPP膜的活性随溶液pH值的降低而增大。在低极化区内，氧在碱性溶液中或中性溶液中的电还原与OH~-浓度无关，而在酸性溶液中，H~+浓度有影响；在高极化区内，溶液pH值影响很小。RRDE（旋转环盘电极）的研究结果表明，在一定的电位范围内，氧在聚CoPP/PC上电还原的主要产物为H_2O_2，H_2O_2一但在盘电极上生成，就不再进一步还原，并同时体随有少量氧按四电子途径还原。若电位在很负的情况下，在盘上生成的H_2O_2能够进一步还原。根据以上的实验现象及结果我们提出了氧在聚CoPP膜上电催化还原的二电子还原机理、四电子还原机理和四电子的串联还原机理，并对上述实验现象的结果给予了一定的解释。

二氧化硫的阳极氧化

本文对贵金属电极和钴卟啉膜电极进行了动力学研究，并根据实验数据提出了SO_2在不同电极材料上的反应机理。一、各种电极材料催化性能的比较用循环伏安法得出SO_2在Pt、Au、Pd电极上的氧化在不同电位区有不同的机理。一种是在低电位区SO_2分子的直接放电，另一种是在高电位区表面吸附氧的化学氧化。在贵金属Ir、Ru、Rh电极上，So_2的氧化只有一种途径，即只能通过电极表面吸附氧的化学氧的化学氧化。根据SO_2在贵金属电极上氧化的峰电位得出SO_2在这些电极上的活性次序如下：Au > Ir > Pd，Ru > Pt > Rh SO_2在钴卟啉膜电极上氧化也只有一种途径，但和Ir、Ru、Rh电极不同，不是通过吸附氧的化学氧化，而是SO_2分子的直接放电。二、氧化机理1、SO_2在Au电极上电化学氧化机理 对SO_2在Au电极上电化学过程进行研究，用稳态极化曲线法测得在较负电位区Tafel线性区的斜率为0.049, 可说明SO_2分子第二个电子的脱除为控制步骤；用计时－电流法、计时－电位法求得SO_2在Au电极上电化学氧化的动力学参数R_6~o为10~(-11)数量级。测量不同电位下交流阻抗的频谱，得到两个明显的半园，表明电极过程包括了中间吸附物的形成。根据实验数据推导SO_2在Au电极上可能的电化学氧化机理如下：H_2SO_3 → H_2SO_3ads H_2(SO_3)_(ads) - e → H_2SO_3~+ H_2SO_3~+ +H_2O → HSO_3+H_3O~+ HSO_3 - e → HSO_3~+ HSO_3~+ + 2H_2O → H_2SO_4+H_3O~+ 2. So_2在Ru电极上的氧化机理在贵金属Ru电极上，SO_2通过吸附氧氧化，提出如下如能的反应机理：Ru + H_2O → Ru(OH)_(ads) + H~+ + e Ru(OH)_(ads) + H_2O → RuO_(ads) + H_3O~+ + e RuO_(ads) + SO_2 + H_2O → Ru + H_2SO_4用稳态法测得Tafel斜率为0.055，限制步骤可能为吸附氧氧化SO_2分子。3、SO_2 在Copp/Pt上的氧化机理在非金属钴卟啉膜电极上，SO_2氧化为SO_2分子的直接放电。稳态测量法得到极化曲线的Tafel斜率为0.107 (α=0.54)。表明SO_2分子的第一电子的脱除为控制步骤；计时－电位法表明SO_2在钴卟啉电极上氧化有个前置的化学反应p在不同电位下测量交流阻抗频谱也为两个半园，表明有中间吸附物形成。根据实验数据推导SO_2氧化的可能机理如下：H_2SO_3 → H_2SO_(3_(ads)) H_2SO_(3_(ads)) <-> H~+ + HSO_(3_(ads))~- HSO_(3_(ads))~- - e → HSO_3 HSO_3 - e → HSO_3~+ HSO_3~+ 2H_2O → H_2SO_4 + H_3O~+

氧的电催化还原和化学修饰电极

本文研究了环反应为非扩散控制的新RRDE理论与相应的新数学处理方法，“聚焦函数”和“切线”法。成功地用上述方法研究了氧电还原反应的机理和求解各步反应的速率常数。研究了扩散层流体动力学扫描的理论，提出了应用快扫转速法测量i-ω曲线，求动力学常数的方法。研究了氧在CoPP/PG电极上的电催化还原和动力学过程。推导了不稳定电极的催化反应速率常数随盘电位和反应电量变化的函数关系。研究了吸附型CoPP/PG电极对H_2O_2的电催化氧化和FePP/PG电极对H_2O_2的电催化还原。研究了四磺化酞青钴掺杂的聚苯胺薄膜（TsPcCo+PA)/GC电极对氧还原反应的电催化行为，提出了六种动力电流的概念和实验求算实际动力电流方程及相应动力电流值的方法。研究了金属原叶啉＝甲酯（MPP, M:Fe, Co, Hz)电化学聚合的机亘，提出了关于中心金属离子在电聚合过程中可能形成一种中间态络合物，促进工烯电氧化成阳离子自由基，引起聚合反应的历程。研究了聚MPP薄膜电极对氧还原反应的电催化行为和动力学过程。研究了通过催化剂在电极表面热处理制备金属四苯基叶啉（MTPP, M:Fe, Co, Ni, Mn, Hz)修饰电极（称HPM/GC)的方法。用多种波谱方法对热处理机理进行了表征。研究了多种因素对HPM／GC电极制备及其对氧还原电催化性能的影响。其中经500 ℃热处理的HPFe/GC和700－800 ℃ 热处理的HPCo/GC对氧还原催化活性增加，稳定性提高一至二个数量级。研究了可溶性聚苯胺（SPA）的合成与溶解方法，并用多种波谱方法进行了表征。研究了分散在不同PH缓冲溶液中的SPA的变色，光谱和电化学行为。研究了SPA在非水溶液中的现场光谱，ESR电化学。研究了聚苯胺（PA）薄膜的化学变色，电位响应和立体化学反应历程。总结了PA变色的规律。

MEASUREMENT OF CATALYTIC ACTIVITY VARIATION FOR H2O2 OXIDATION AT A COBALT PORPHYRIN COATED ELECTRODE

A rapid rotation-scan method was used for the electrocatalytic oxidation of H2O2 at a cobalt protoporphyrin modified pyrolytic graphite electrode (CoPP/PG). The rate constant of H2O2 oxidation at the CoPP/PG electrode at different potentials and in different pH solutions was measured. The variation of catalytic activity with reaction charges (Q) passed through the electrode was analyzed. This provided a convenient electrochemical method to study the passivation and poisoning of catalytic sites with time.

ANODIC-OXIDATION OF HYDRAZINE ON GLASSY-CARBON MODIFIED BY MACROCYCLIC TRANSITION-METAL COMPLEXES .1. COBALT PROTOPORPHYRIN DIMETHYL ESTER MODIFIED ELECTRODE

The electrocatalytic oxidation of hydrazine (N2H4) on a glassy carbon electrode (GC) modified by monolayer and polymer films of cobalt protoporphyrin dimethyl ester (CoPP) has been studied. Both the monolayer and polymer films of CoPP are very active to the anodic oxidation of N2H4. The activity of CoPP for the anodic oxidation of N2H4 is dependent on the pH of the solution, and the thickness of polymerized CoPP film. The oxidation kinetics were examined by methods of cyclic voltammetry, rotating disc electrodes and steady-state polarization measurement.

化学修饰电极的研究在电化学聚合的钴原卟啉薄膜电极上氧还原反应的电催化和动力学

用循环伏安法(CV),旋转圆盘和环盘电极(RDE和RRDE)研究了电化学聚合的钴原卟啉二甲酯薄膜玻碳电极〔聚(CoPP)/GC〕对氧还原反应的电催化和动力学。在不同pH缓冲溶液中,在聚(CoPP)/GC电极上氧的还原反应主要为二电子还原为H_2O_2的过程。实验表明,当聚(CoPP)薄膜在玻碳(GC)表面的覆盖度(Γ)大于6×10~(10)mol/cm~2时,催化反应受聚(CoPP)薄膜内电荷传输过程控制;当Γ值小于6×10~(-10)mol/cm~2时,受聚(CoPP)与氧分子间的催化反应速率控制。随电位负移,i_k,ΚΓ,n和K值均增加;随Γ值或溶液pH增加,i_k,ΚΓ和K值减小,而n值略有增加。

Are American Youth Alienated From Organized Religion?

The purpose of the project is to research the shape and influence of religion and spirituality in the lives of U.S. adolescents; to identify effective practices in the religious, moral, and social formation of the lives of youth; to describe the extent to which youth participate in and benefit from the programs and opportunities that religious communities are offering to their youth; and to foster an informed national discussion about the influence of religion in youth's lives, in order to encourage sustained reflection about and rethinking of our cultural and institutional practices with regard to youth and religion.

Seven new loci associated with age-related macular degeneration

Age-related macular degeneration (AMD) is a common cause of blindness in older individuals. To accelerate the understanding of AMD biology and help design new therapies, we executed a collaborative genome-wide association study, including >17,100 advanced AMD cases and >60,000 controls of European and Asian ancestry. We identified 19 loci associated at P <5 × 10(-8). These loci show enrichment for genes involved in the regulation of complement activity, lipid metabolism, extracellular matrix remodeling and angiogenesis. Our results include seven loci with associations reaching P <5 × 10(-8) for the first time, near the genes COL8A1-FILIP1L, IER3-DDR1, SLC16A8, TGFBR1, RAD51B, ADAMTS9 and B3GALTL. A genetic risk score combining SNP genotypes from all loci showed similar ability to distinguish cases and controls in all samples examined. Our findings provide new directions for biological, genetic and therapeutic studies of AMD.

Diagnostic accuracy of pulmonary host inflammatory mediators in the exclusion of ventilator-acquired pneumonia

Background: Excessive use of empirical antibiotics is common in critically ill patients. Rapid biomarker-based exclusion of infection may improve antibiotic stewardship in ventilator-acquired pneumonia (VAP). However, successful validation of the usefulness of potential markers in this setting is exceptionally rare.

Objectives: We sought to validate the capacity for specific host inflammatory mediators to exclude pneumonia in patients with suspected VAP. 

Methods: A prospective, multicentre, validation study of patients with suspected VAP was conducted in 12 intensive care units. VAP was confirmed following bronchoscopy by culture of a potential pathogen in bronchoalveolar lavage fluid (BALF) at >10⁴ colony forming units per millilitre (cfu/mL). Interleukin-1 beta (IL-1β), IL-8, matrix metalloproteinase-8 (MMP-8), MMP-9 and human neutrophil elastase (HNE) were quantified in BALF. Diagnostic utility was determined for biomarkers individually and in combination. 

Results: Paired BALF culture and biomarker results were available for 150 patients. 53 patients (35%) had VAP and 97 (65%) patients formed the non-VAP group. All biomarkers were significantly higher in the VAP group (p<0.001). The area under the receiver operator characteristic curve for IL-1β was 0.81; IL-8, 0.74; MMP-8, 0.76; MMP-9, 0.79 and HNE, 0.78. A combination of IL-1β and IL-8, at the optimal cut-point, excluded VAP with a sensitivity of 100%, a specificity of 44.3% and a post-test probability of 0% (95% CI 0% to 9.2%). 

Conclusions: Low BALF IL-1β in combination with IL-8 confidently excludes VAP and could form a rapid biomarker-based rule-out test, with the potential to improve antibiotic stewardship.