Antimicrobial activity of silymarin mediated zinc oxide and hydroxy apatite nanoparticles against oral pathogens

The nanoparticles such as hydroxyapatite, zinc oxide, titanium dioxide and zirconium nanoparticles have application in dentistry. Therefore, it is of interest to document the antimicrobial activity of silymarin mediated zinc oxide and hydroxy apatite nanoparticles against oral pathogens. Hence, we synthesized hydroxyapatie and zinc oxide nanoparticles with silymarin and characterized by UV-visible spectrophotometer. Data shows that silymarin mediated HAP and ZnO nanoparticles have antimicrobial activity against oral pathogens such as Pseudomonas sp, Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis and Candida albicans.     

A new Sphagesaurus (Mesoeucrocodylia: Notosuchia) from the Upper Cretaceous of Monte Alto City (Bauru Group,Brazil), and a revision of the Sphagesauridae

Oxygen consumption and ammonia excretion rates were assessed for Terebratulina retusa (L.) held under 3 different regimes of temperature and food availability. These were: 5.6?C, no food (cold, starved); 5.8?C, food present (cold, fed) and 10.7?C food present (warm, fed), which simulated winter conditions, summer conditions and an intermediate treatment. Regressions of oxygen consumption on ash‐free dry weight (AFDW) had slopes which were not significantly different from each other and ranged from 0.953 to 0.999. A common slope of 0.976 was calculated and intercepts based on the common slope used to compare oxygen consumption in each treatment. The rise from cold, starved conditions to warm, fed was 24.5 per cent and this was significant (P < 0.05). Other differences were not significant (P > 0.05) but the cold, fed result was 12.6 per cent higher than cold, starved. Therefore feeding and temperature probably account for equivalent proportions of the rise in metabolism from winter to summer. Ammonia production data were much more variable. Excretion rates of a 50 mg AFDW individual (in ng‐at NH₃‐N.h^‐1) were as follows: cold, starved: 30.2 cold, fed: 7.1; and warm, fed: 22.9. Oxygen to nitrogen (O:N) ratios reflected these results. Mean O:N ratios were: cold, starved: 8.0; cold, fed: 42.4; warm, fed: 16.3. This shows that the simulated winter group relied heavily on protein to fuel their metabolism, the simulated summer group were less dependent on protein and the intermediate group probably used lipids and carbohydrates to fuel metabolic demands. This possibly reflected a trade off between food supply and increased metabolism from treatment to treatment, demonstrating a flexibility which could have been a contributing factor in the ecological tolerance and geological longevity of some brachiopods.     

Genetic Diversity and Population Structure Among Oat Cultivars and Landraces

In this study, genetic diversity among 177 oat (Avena sativa L.) accessions including both white and red oat landraces and 36 commercial cultivars was studied for simple sequence repeat (SSR) loci. Thirty-one genomic and expressed sequence tags (EST)-derived primer pairs were selected according to high polymorphism from an initial 66 SSR batch. Markers revealed a high level of polymorphism, detecting a total of 454 alleles. The average gene diversity for the whole sample was 0.29. Genetic similarity, calculated using the Dice coefficient, was used for cluster analysis, and principal component analysis was also applied. In addition, population structure using a Bayesian clustering approach identified discrete subpopulation based on allele frequency and showed similar clustering of oat genotypes in four groups. Accessions could be classified into four main clusters that clearly separated the commercial cultivars, the red oat landraces and two clusters of white oat landraces. Cultivars showed less diversity than the landraces indicating a reduction of genetic diversity during breeding, whereas white oat landraces showed higher diversity than red ones. The average polymorphic information content of 0.80 for the SSR loci indicated the usefulness of many of the SSR for genotype identification. In particular, two markers, MAMA5 and AM04, with a total of 50 alleles and a high discrimination power (>0.90), were sufficient to discriminate among all commercial cultivars studied highlighting their potential use for variety identification.     

Quantifying the historic contribution of Olympia oysters to filtration in Pacific Coast (USA) estuaries and the implications for restoration objectives

The Olympia oyster, Ostrea lurida Carpenter, was formerly widespread in many US Pacific coast estuaries. Following dramatic declines in the late 1800s and early 1900s, this species is now the focus of renewed restoration efforts. Restoration is undertaken for brood stock rehabilitation as well as a range of ecosystem services such as filtration; however, these ecosystem services are as yet poorly quantified. We present the first laboratory measurements of filtration rates (FR) for O. lurida, to which we fit a model of FR as a function of dry tissue weight and water temperature. We find that O. lurida has a FR at optimum temperature similar to previously established means across oyster species at 1 g dry tissue weight (DTW), but lower than many Crassostrea species. We also find that the allometric exponent relating FR to DTW in O. lurida is lower than the previously published mean across oyster species. Based on our derived filtration rates and historical data, we estimate the historic impact of filtration by O. lurida in five Pacific coast estuaries. We find that historic O. lurida populations did not have the capacity to filter the full volume of the estuary within the estuary residence time in any of the estuaries examined. This result is primarily driven by the low water temperatures and the short estuary residence times that typify the Pacific coast. We conclude that, unlike Crassostrea virginica Gmelin on the Atlantic and Gulf coasts, the Olympia oyster was not historically a dominant force in regulating seston concentrations at large scales in Pacific coast estuaries. Given the differences in the ecological role and habitat structure of these two oyster species, we recommend that analogies between them be drawn with caution. We discuss the implications of our results for developing restoration objectives.     

The timing of sea ice formation and exposure to photosynthetically active radiation along the Western Antarctic Peninsula

Understanding the flow of solar energy into ecosystems is fundamental to understanding ecosystem productivity and dynamics. To gain a better understanding of this fundamental process in the Antarctic winter sea ice, we produced a model that estimates the time-integrated exposure of seasonal Antarctic sea ice to PAR through the use of remotely sensed sea ice concentrations, sea ice movement and spatially distributed PAR calculations that account for cloud cover and have applied this model over the past three decades. The resulting spatially distributed estimates of sea ice exposure to PAR by mid-winter are evaluated in context of changes in the timing of sea ice formation that have been documented along the Western Antarctic Peninsula (WAP) region and its potential effects on the variation (seasonal and inter-annual) in the accumulation of sea ice algae in this region. The analysis shows the ice pack is likely to have large inter-annual variations (10–100 fold) in productivity throughout the autumn to winter transition in the sea ice along the WAP. Moreover, the pack ice is likely to have spatial structure in regards to biological processes that cannot be determined from analysis of sea ice concentration information alone. The resulting inter-annual variations in winter processes are likely to affect the dynamics of Antarctic krill (Euphausia superba).     

The Diversity of Flower Flies (Diptera: Syrphidae) in Colombia and Their Neotropical Distribution

In Colombia, like most Neotropical countries, faunistic studies on flower flies have been occasional and most of them have been primarily focused on taxonomy. Colombia is the second-most species-rich country in flower fly diversity in the Neotropics after Brazil, and has one of the highest numbers of species per unit area (2.49 per 10,000?km²), based on a review of literature and national collections. Including new data presented here, a total of 47 genera and 300 species are recorded in Colombia. The genera Scaeva Fabricius and Lycastrirhyncha Bigot, as well as 101 species are recorded here for the first time. The altitudinal range and the distribution of the flower fly genera in Colombia are presented. A preliminary comparison of the fauna of Colombia with that of other Neotropical countries is given. A historical perspective is also provided in order to illustrate how Colombian Syrphidae knowledge has progressed over the last 168?years. Information presented here will be useful for ongoing and future biodiversity research as well as conservation projects on Syrphidae in the Neotropical region.     

Working with living krill - the people and the places

The fascination of Antarctic scientists with Antarctic krill and their capabilities has a long and varied history, and prompted many scientists to maintain and manipulate krill under laboratory conditions. Starting in the Discovery era with Mackintosh at the King Edward Point labs on South Georgia, 1930, scientists have collected krill from sailing vessels, small boats, inflatable zodiacs and large ice-breaking vessels. Krill have been maintained in small and large jars, deep rectangular tanks, large round tanks and in flow-through and recycling systems. They have been maintained both on board research vessels and in laboratories, in flowing seawater systems at ambient conditions and in temperature-controlled environmental rooms. A few researchers have transported living krill back to their home laboratories, for example tropical laboratories in Japan (Murano) and Australia (Ikeda), temperate laboratories (Nicol) in Australia, a northern European laboratory in Germany (Marschall) and a sunny maritime laboratory in California (Ross and Quetin). The goals have been varied: short-term experiments to understand in situ physiological rates, long-term experiments to test the effects of manipulations or controlled changes in environmental conditions, and behavioral responses. We take you on a brief historical tour as we trace the lineage of modern day research on living Antarctic krill.     

Variations in cruropedal musculature

The comparative anatomy of primate musculature has been established frequently from single specimens or small samples which are assumed to be typical for their species. However, a series of dissections of platyrrhine monkeys reported here reveals considerable variation within species and genera. Selected muscles of the leg and foot were examined and compared for discrete variations in attachments. The results were supplemented by observations in the anatomical literature for these and other primates. The range of variation reported across the order also presents itself as widespread polymorphism within most taxonomic groups, down to the species level. Since correlations with phylogeny and positional behavior are expressed only weakly, adaptationist explanations can account for only a part of the variation. Functional redundancy among the muscles supports the conclusion that the behavioral significance of the variations is slight. It is apparent that both genetic and nongenetic factors influence muscle form, and it is likely that observed polymorphisms have been characteristic of populations throughout primate evolution. Therefore, traits involving muscular form, especially as observed on small samples, within species, should be used cautiously in phyletic and adaptationist analyses.