Study of novel rosin-based biomaterials for pharmaceutical coating

The film forming and coating properties of Glycerol ester of maleic rosin (GMR) and Pentaerythritol ester of maleic rosin (PMR) were investigated. The 2 rosin-based biomaterials were initially characterized in terms of their physicochemical properties, molecular weight (Mw), and glass transition temperature (Tg). Films were produced by solvent evaporation technique on a mercury substrate. Dibutyl sebacate plasticized and nonplasticized films were characterized by mechanical (tensile zzzz strength, percentage elongation, and Young's modulus), water vapor transmission (WVT), and moisture absorption parameters. Plasticization was found to increase film elongation and decrease the Young's modulus, making the films more flexible and thereby reducing the brittleness. Poor rates of WVT and percentage moisture absorption were demonstrated by various film formulations. Diclofenac sodium-layered pellets coated with GMR and PMR film formulations showed sustained drug release for up to 10 hours. The release rate was influenced by the extent of plasticization and coating level. The results obtained in the study demonstrate the utility of novel rosin-based biomaterials for pharmaceutical coating and sustained-release drug delivery systems.     

Modern and ancient olive stands near Sagalassos (south-west Turkey) and reconstruction of the ancient agricultural landscape in two valleys

Aim To study the present‐day olive stands and their ecology in the eastern part of the territory of the ancient city of Sagalassos, to study the variation of olive pollen production and dispersal near the olive stands, to establish a modern pollen reference model, and to compare Hellenistic–Roman pollen data from two wetlands with this modern reference model. Location Eastern part of the territory of the ancient city of Sagalassos, western Taurus mountain range in south‐west Turkey. Methods The study is based on field survey, pollen analysis of surface samples, multivariate statistics of modern pollen data and the use of ‘modern analogues’ in comparison with Hellenistic–Roman pollen samples. Results A field survey revealed the presence of 35 olive stands in the study area. These are mainly small‐scale stands. The olive pollen representation in the surface samples is highly variable. Two groups of modern ‘olive’ pollen spectra could be distinguished: (1) a group representing mainly olive stands from lush and moist mixed orchards; and (2) a group representing mainly olive stands from open small‐scale olive stands in combination with annual crop agriculture. Although no ‘perfect’ modern analogue was found for the Hellenistic–Roman pollen data, the fossil pollen data show similarities with modern spectra from the second group, due to the presence of relatively high pollen values for secondary anthropogenic indicators. Main conclusion A well‐organized and diverse, but time‐ and energy‐consuming, agricultural system was maintained nearby the wetlands of Çanakl? soils, presumably to maximize the yields in both valleys.     

A note on the KNM-ER 999 hominid femur

The KNM-ER 999 hominid femur, in light of improved knowledge of later Pleistocene human postcranial morphology and ongoing reassessments of the emergence of modern humans in Africa, appears morphologically aligned with early modern humans rather than with late archaic humans. This is reflected especially in its having a clear pilaster, a proximally positioned minimum diaphyseal breadth (thereby lacking a proximo-medial diaphyseal buttress) and an exceptionally high neck-shaft angle. In these features, and especially the fast, it shows affinities to the Levantine Qafzeh-Skhul early modern human sample. However, the uncertainty regarding its stratigraphic provenience (early Late Pleistocene versus early Holocene) makes its relevance to the emergence of modern humans in Africa tenuous.     

陕西黄龙人头盖骨的多元分析比较研究

本文使用主成分分析的多元统计方法比较中国与欧洲和西南亚不同类型的智人的额骨材料。研究结果支持黄龙头盖骨可能代表东亚解剖学上现代智人—古老种群的结论。中国的一系列标本与欧洲和西亚的一系列标本从古老智人到解剖学上现代智人的进化过程存在着差异,最终在额骨的主要形态方面还是趋于一致。     

The M. obturator internus sulcus on Middle and Late Pleistocene human ischia

Recent human ischia and those of Middle and Late Pleistocene hominids exhibit variation in the cranio-caudal location of the sulcus for the internal obturator muscle as it rounds the ischium through the lesser sciatic notch, from being fully cranial of the ischial tuberosity, to bordering the tuberosity, to crossing the superior tuberosity. Among two recent human samples, all three forms exist, with the cranial position of the sulcus being more common in a 20th century Euroamerican sample whereas the intermediate one predominates in a horticultural late prehistoric Amerindian sample. The available Pleistocene Homo fossil remains exhibit the full range of variation with no one form being dominant in Middle Pleistocene archaic humans and Middle Paleolithic late archaic and early modern humans. It is only within the Upper Paleolithic that the cranial and intermediate locations for the sulcus become predominant. These patterns therefore indicate that it is inappropriate to use this feature for distinguishing later Pleistocene hominid groups. © 1996 Wiley-Liss, Inc.     

A new methodology for reconstructing climate and vegetation from modern pollen assemblages: an example from British Columbia

Aim We used modern pollen assemblages to develop a method for climate reconstruction that reduces the spatial autocorrelation of residuals and accounts for the strong topographic and climatic variation that occurs in British Columbia, Canada. Location British Columbia, Canada, including sites both on the mainland and on adjacent islands (Queen Charlotte Islands and Vancouver Island). Methods New pollen assemblages from surface‐sediment samples collected in British Columbia were combined with other published and unpublished samples (n = 284). Multivariate rank‐distances between sample sites and a randomized set of sites within the province were calculated for climate parameters to determine whether gaps in the current network of present‐day pollen sample sites exist. Lacustrine surface‐sediment pollen assemblages (n = 145) were ordinated using non‐metric multidimensional scaling (NMDS), and a generalized additive model (GAM) was used to reconstruct modern mean warmest month temperature (MWMT) and mean annual precipitation (MAP) from the NMDS ordination. The results were compared with standard climate reconstruction techniques, including the modern analogue technique, partial least squares, weighted averaging, weighted averaging–partial least squares and factor analysis. Results Reconstructions of MWMT and MAP using NMDS and GAM were comparable to those of existing models. When reconstructing MWMT, the NMDS/GAM method had a lower root‐mean‐squared error of prediction (RMSEP), lower spatial autocorrelation and higher correlation with observed temperature values than the other methods tested. When reconstructing MAP, the partial least squares method performed better than the NMDS/GAM method for RMSEP and correlation with observed values; however, the NMDS/GAM method had a lower spatial autocorrelation of residuals. Main conclusions NMDS reveals strong relationships among modern pollen assemblages, vegetation and climate parameters. Climate models using NMDS and GAM are comparable to other palaeoecological reconstruction models, but provide lower spatial autocorrelation of residuals for both parameters tested. An inverse distance‐weighted surface of multivariate rank‐climate distances generated from the network of pollen sample sites indicates that greater sampling intensity in north‐western and central‐interior British Columbia is required in order to obtain an accurate representation of climatic and vegetation diversity in the province.     

Influence of formulation and process parameters on pellet production by powder layering technique

The goal of the present study was to evaluate the influence of the formulation and operating conditions on pellet preparation by pan technique. To this end, a new pelletization process, typified by the application of powdered drug on sugar-based cores using the GS coating system was studied. Inert cores were intermittently treated with micronized drug powder and adhesive solution. This treatment led to the formation of multiple layers of drug particles around an inert core resulting in the production of pellets that can further be coated by different polymers to obtain modified release formulations. Different procedures have been used to evaluate a series of important parameters such as initial core weight; speed of powder application; speed, type, and position of the atomizers; atomization degree: temperature; and air cap. Good yield of drug layering was obtained by adjusting the quantity of both the drug powder to apply and the binder solution. Pellets obtained following the optimal operating conditions (defined in a pre-formulation study) were film coated with the acrylic polymer Eudragit L30D in order to produce a model formulation consisting of enteric polymer-coated pellets containing ibuprofen. During its preparation, the formulation showed no degradation of the drug, moreover, a low percentage of residual humidity was obtained, indicating that this system is very efficient for the production of highly stable formulations. This study showed the good performance of the GS automated pan-coating system in obtaining enteric coated pellets prepared by powder layering technique using aqueous solutions.     

U-series and ESR analyses of bones and teeth relating to the human burials from Skhul

In order to resolve long-standing issues surrounding the age of the Skhul early modern humans, new analyses have been conducted, including the dating of four well-provenanced fossils by ESR and U-series. If the Skhul burials took place within a relatively short time span, then the best age estimate lies between 100 and 135 ka. This result agrees very well with TL ages obtained from burnt flint of 119+/-18 ka (Mercier et al., 1993). However, we cannot exclude the possibility that the material associated with the Skhul IX burial is older than those of Skhul II and Skhul V. These and other recent age estimates suggest that the three burial sites, Skhul, Qafzeh and Tabun are broadly contemporaneous, falling within the time range of 100 to 130 ka. The presence of early representatives of both early modern humans and Neanderthals in the Levant during Marine Isotope Stage 5 inevitably complicates attempts at segregating these populations by date or archaeological association. Nevertheless, it does appear that the oldest known symbolic burials are those of early modern humans at Skhul and Qafzeh. This supports the view that, despite the associated Middle Palaeolithic technology, elements of modern human behaviour were represented at Skhul and Qafzeh prior to 100 ka.     

Birds of prey as limiting factors of gamebird populations in Europe: a review

Whether predators can limit their prey has been a topic of scientific debate for decades. Traditionally it was believed that predators take only wounded, sick, old or otherwise low-quality individuals, and thus have little impact on prey populations. However, there is increasing evidence that, at least under certain circumstances, vertebrate predators may indeed limit prey numbers. This potential role of predators as limiting factors of prey populations has created conflicts between predators and human hunters, because the hunters may see predators as competitors for the same resources. A particularly acute conflict has emerged over the past few decades between gamebird hunters and birds of prey in Europe. As a part of a European-wide research project, we reviewed literature on the relationships between birds of prey and gamebirds. We start by analysing available data on the diets of 52 European raptor and owl species. There are some 32 species, mostly specialist predators feeding on small mammals, small passerine birds or insects, which never or very rarely include game animals (e.g. hares, rabbits, gamebirds) in their diet. A second group (20 species) consists of medium-sized and large raptors which prey on game, but for which the proportion in the diet varies temporally and spatially. Only three raptor species can have rather large proportions of gamebirds in their diet, and another seven species may utilise gamebirds locally to a great extent. We point out that the percentage of a given prey species in the diet of an avian predator does not necessarily reflect the impact of that predator on densities of prey populations. Next, we summarise available data on the numerical responses of avian predators to changing gamebird numbers. In half of these studies, no numerical response was found, while in the remainder a response was detected such that either raptor density or breeding success increased with density of gamebirds. Data on the functional responses of raptors were scarce. Most studies of the interaction between raptors and gamebird populations give some estimate of the predation rate (per cent of prey population taken by predator), but less often do they evaluate the subsequent reduction in the pre-harvest population or the potential limiting effect on breeding numbers. The few existing studies indicate that, under certain conditions, raptor predation may limit gamebird populations and reduce gamebird harvests. However, the number and extent of such studies are too modest to draw firm conclusions. Furthermore, their geographical bias to northern Europe, where predator-prey communities are typically simpler than in the south, precludes extrapolation to more diverse southern European ecosystems. There is an urgent need to develop further studies, particularly in southern Europe, to determine the functional and numerical responses of raptors to gamebird populations in species and environments other than those already evaluated in existing studies. Furthermore, additional field experiments are needed in which raptor and possibly also mammalian predator numbers are manipulated on a sufficiently large spatial and temporal scale. Other aspects that have been little studied are the role of predation by the non-breeding part of the raptor population, or floaters, on the breeding success and survival of gamebirds, as well as the effect of intra-guild predation. Finally there is a need for further research on practical methods to reduce raptor predation on gamebirds and thus reduce conflict between raptor conservation and gamebird management.