172,655 research outputs found
Heavy metal pollution and blackheaded gull (larus ridibundus L.) breeding ecology
No full textHeavy metals in air, soil and water are a global problem and present a growing threat to the environment. These metals may have profound consequences for birds and can cause a number of sub-lethal effects, such as decreased reproductive success. The concentrations of selected heavy metals (As, Cd. Co, Cu, Fe, Pb, Mn, Ni, V, Zn) and Se in eggs and feathers from populations of black-headed gulls (Larus ridibundus L.) located on different colonies in the UK, which have different characteristics and are subject to different sources, types and degrees of pollution, were examined. Concentrations of As, Cu, Pb, Ni, Se and V measured in black-headed gull eggs were consistently high relative to those reported in previous field studies with other gull species. However, no significant effect was observed on the egg characteristics in terms of egg size and dimensions, shell thickness and index as a result of concentrations of metals measured in this study. Concentrations of Co, Fe and Ni were significantly negatively correlated with yolk:albumen ratio in the egg. The usefulness of sampling eggs to provide a reflection of local contamination has been demonstrated, with concentrations related to local sources of metal pollution and site differences reflected in sediment concentrations from previous studies. The importance of taking into account diffuse and historical pollution in addition to point source discharges has also been highlighted. As, Fe, Mn, Pb, Se, V and Zn were found at significantly higher concentrations in egg contents than egg shell, and Cd, Co and Ni concentrations were higher in shell than contents. Cu was distributed approximately equally. Within the egg contents, concentrations of As, Cu, Se and V were higher in the albumen than in the yolk, and Co, Fe, Mn, Ni, Pb and Zn concentrations were higher in the yolk than the albumen. Cd was found mainly in the shell and concentrations in egg contents were largely undetectable. Comparisons were made between a colony subject to high-level commercial egg harvesting and an un-harvested site, and between pre- and post-harvesting eggs on the harvested site. Postcollection eggs were found to be of significantly lower quality than the pre-collection eggs and the eggs from the uncollected site, as indicated by yolk:albumen ratio. Concentration of metals in eggs as a result of relaying forced by commercial harvesting has been demonstrated, with concentrations of Co, Fe and Ni significantly higher in post-collection eggs compared to precollection eggs. Average nesting density was significantly lower on the collected colony than the uncollected colony. No effect on egg size was found as a result of changes in nesting density. Concentrations of metals in black-headed gull chick down were measured and compared to egg data in order to assess the usefulness of feathers as a tool for non-destructive monitoring of metal pollution. The results suggest that feathers may be good indicators for As and Zn, and possibly also for Mn and Ni. However, the sample masses were very small and for a number of metals concentrations were largely undetectable using the analytical equipment available in this study. Future work with larger samples of down would be prudent to further examine the use of chick down to provide an indication of the level of pollution to which birds are exposed. The importance of using appropriate washing procedures to remove exogenous contamination of feathers to assess internal concentrations has been demonstrate
Letter from J[oseph] C. Pickard to John Muir, 1909 Sep 2.
No full text[2]cause of the people. It is a good cause. It shall ultimately prevail. It shall ultimately triumph . Thomas Muir in Court of Judiciary. Aug. 20. 1793. - The cause did ultimately triumph & the people erected the monument. You must know the spot & its memory, as I believe your early life was not far away.- I have thought you must of that noble stock, for in you is somewhat of that heroic grandeurI wish you might meet my brother J. L. who lives in Cupertino (85 years of age) & his grandson in San Francisco, Perhaps you remember Henry Butler & my son Charles as boys about the university. Henry is a lawyer in Superior, & Charles a lawyer in Chicago. Charles spent a week or two this summer with his invalid wife in the Yosemite. I hoped he would find you. Both boys are successful in their profession.Very cordially yoursJ. C. Pickard[3]PS. Ninety years ago my wife\u27s grandfather James St[illegible] & his son published \u27Illustrations of Edinburg with a history of the city. One of the engravings is of the old Tol. booth. I found a copy in a second hand book store, & brought it away with me paying $2.25 for it. A rare work now. MR. St[illegible] was a distinguished delineator & engraver in London.- In the description of Hume\u27s monument is given a suggested epitaph, which you may not have seen. I copy it. Within this circular idea, vulgarly called a tomb- Rest the impressions & ideas That constituted Hume. I quote from memory.JCP04573https://scholarlycommons.pacific.edu/jmcl/31393/thumbnail.jp
Letter from S[amuel] T[homas] Pickard to John Muir, 1913 Jan 30.
No full textAmesbury, Mass.Jan 3. 1913-Mr. John Muir:I have always been greatly interested in all you have written. My brother Prof. Joseph C. Pickard used to talk about you so much, before I found you in print. I wonder if my brother is remembered by you. He was Prof. in the University of Wisconsin, & another brother, Josiah L. Pickard, 053652was one of the Regents of the University, & also Supt. of the Schools of the State.I thought it possible that there was a reference to my brother in the Feb. No. of the Atlantic. He is not now living, but the older brother Josiah is still alive in 89th year, at Cupertino, Cal.Joseph\u27s enthusiasm whenever he spoke of you, & that was often, always impressed me.I am Whittier\u27s biographer, & am living in his Amesbury house.Very truly yoursS. T. Pickard05365https://scholarlycommons.pacific.edu/jmcl/42204/thumbnail.jp
Lasetta Pickard, Toledo, Ohio, 1968
No full textA photo of Lasetta Pickard, a teacher at Start High School, as it appeared in The Shield, the school's yearbook. Roy C. Start High School is located at 2010 Tremainsville Road in Toledo, Ohio. Terms associated with the photograph are: Roy C. Start High School (Toledo, Ohio) | Teachers | Pickard, Lasetta | Classrooms | Portraits | 2010 Tremainsville Road (Toledo, Ohio
Enna O. Pickard-Cambridge 1897
No full textEnna O. Pickard-Cambridge 1897 Enna O. Pickard-Cambridge 1897: 232, figs 13 a, b, c; Sierwald 1990: 51; Carico 1993: 226; Sierwald 1993: 63. Type species. Enna velox O. Pickard-Cambridge 1897, by original designation. Diagnosis. See Silva et al. (2008).Published as part of Cruz, Estevam L., Silva, Da, Viquez, Carlos & Lise, Arno A., 2012, On the Neotropical spider genera Enna O. Pickard-Cambridge, 1897 and Syntrechalea F. O. Pickard-Cambridge, 1902 (Araneae, Lycosoidea, Trechaleidae): descriptions, taxonomic notes and new records, pp. 55-62 in Zootaxa 3334 on page 56, DOI: 10.5281/zenodo.28129
Lasetta Pickard, Toledo, Ohio, 1966
No full textA photo of Lasetta Pickard, taken for The Shield, Roy C. Start's annual yearbook. The high school was located at 2010 Tremainsville Road in Toledo, Ohio. Terms associated with the photograph are: Roy C. Start High School (Toledo, Ohio) | Teachers | Pickard, Lasetta | Classrooms | Portraits | High school boy
Accurate first principles prediction of O-17 NMR parameters in SiO2: Assignment of the zeolite ferrierite spectrum
No full textO-17 NMR parameters, both the chemical shifts and the quadrupolar parameters, are calculated for SiO2 polymorphs using density functional theory with the generalized gradient-corrected PBE functional. The gauge including projector augmented wave (GIPAW) method (Pickard, C. J.; Mauri, F. Phys. Rev. B 2001, 63, 245101) ensures the reproduction of all electron results while using computationally efficient pseudopotentials. The use of plane-waves permits fully converged calculations to be performed on structures containing 144 atoms in the unit cell, without the need to resort to the cluster approximation. The calculated NMR parameters of cristobalite, quartz, coesite, and faujasite are in excellent agreement with experimental data. This demonstrates that density functional theory is able to reproduce with high accuracy the O-17 NMR parameters in SiO2 systems. This precision is used to assign the spectrum of the zeolite ferrierite. The data calculated for SiO2 are used to confirm that no simple correlation between the chemical shift and Cq NMR parameters and Si-O-Si angle exists, emphasizing the importance of predictive theories in this field
Synthesis and cardioprotective activities of green tea polyphenols and their analogues
No full textCardiovascular disease is a major killer worldwide and it is becoming clear the significance of our diet in curbing the disease. Green tea is one of the most widely consumed beverages in the world and has recently attracted significant attention in the scientific community for its health benefits. Its consumption has been associated with lower incidences of coronary artery diseases in the Japanese population. This is mainly attributed to its polyphenolic constituents that include epicatechin, epicatechin gallate, epigallocatechin and epigallocatechin gallate. The aim of this research was to synthesise the four major polyphenols present in green as well as analogues. These compounds would then be tested on H9C2 cardiac myoblast cells and neonatal rat cardiomyocytes in order to further understand the structure-activity relationship as well as potentially improve the cardioprotective function of these polyphenols following oxidative stress and ischaemia/reperfusion injury focusing on the expression of STAT-1 and ERK-1/2 proteins. In H9C2 cardiac myoblast cells following the induction of oxidative stress using H2O2, EGCG, EGC and to a minor extent ECG inhibited STAT-1 activation but not ERK- 1/2 phosphorylation suggesting that although the ERK-1/2 pathway gets activated, its downstream activation of STAT-1 is inhibited by the above polyphenols. EC, on the other hand, inhibited ERK-1/2 activation which in turn cannot activate STAT-1. Quantitative assessment of viable cells showed that pretreatment with EGCG resulted in the lowest amount of non-viable cells reducing cell death by 30%. With neonatal rat cardiomyocytes following ischaemia/reperfusion injury, pretreatment with EGCG reduced the amount of non viable cells by 5% but pretreatment with acetylated EGCG at half the concentration of EGCG reduced non-viable cells by 8%. Structure-activity relationships of the green tea polyphenol analogues identified some key aspects in the structures of the polyphenols important in their cardioprotective function. Results indicated that ABD ring system is required for cardioprotective function but the presence of a third OH group in the ring may not be necessary. Substitution of ring C with benzoic and naphthoic rings improved the potency by more than 13-fold compared to EGCG with EC50 values of 1.60 and 0.77 ?M respectively. Further research into these analogues could realise their potential and contribute to the understanding of the cardioprotective activities of green tea. A review on the previous synthesis approaches, isolation and biosynthesis of the green tea polyphenols is presented in Chapter 1 and also the different signalling pathways of interest in this work. An evaluation of the biological activities of the four major polyphenols is provided in Chapter 3. Experimental procedure and characterisation data are in Chapter 5
Tinus minutus F. O. Pickard-Cambridge 1901
No full textTinus minutus F. O. Pickard-Cambridge, 1901 Tinus minutus F. O. Pickard-Cambridge, 1901: 311, pl. 30, fig 12 (description of the female); Carico, 1976: 70, figs 4, 14–15, 24– 25 (description of the male). New record. GUATEMALA, Departamento de Petén, Cerro Cahui [16 ° 54 ' N, 90 ° 17 'W], 1 3, 1 Ƥ, 10.VII. 2006, C. Viquez (INBio). Distribution. Mexico, Guatemala, Costa Rica (Fig 1).Published as part of Cruz, Estevam L. & Silva, Da, 2012, A new species and new records of Tinus F. O. Pickard-Cambridge, 1901 (Araneae: Pisauridae), pp. 65-68 in Zootaxa 3395 on page 67, DOI: 10.5281/zenodo.28180
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