(η5-Cyclopentadienyl)(2-naphthylethynyl)(triphenylphosphine-κP)nickel(II)

The title compound, [Ni(C₅H₅)(C₁₂H₇)(C₁₈H₁₅P)], does not contain strong hydrogen-bond donors or acceptors and the primary interactions are limited to those of the weak C-H...π(arene) type and mainly involving the arene rings

Targeted delivery of platinum-based anticancer complexes

The most widely used anticancer drugs are platinum-based. Their efficacy might be improved by carriers which can transport large numbers of Pt centres, shield the drug from premature activation, and/or deliver Pt specifically to cancer cells using vectors which recognise specific targets. We describe recent progress using functionalized carbon nanotubes (CNTs) and nanorods, hollow Prussian blue (HPB), magnetic iron oxide and gold nanoparticles, liposomes, nanogels and polymers, as well as active targeting by conjugation to biodegradable proteins and peptides (e.g. EGF, heparin, herceptin, somatostatin and TAT). Spatially targeted activation of PtIV prodrugs using light is also a promising approach. Interestingly, use of these new delivery and targeting systems for platinum drugs can lead to species with unusual reactivity which can kill cancer cells by new mechanisms

The Routine Use of Antibiotics to Promote Animal Growth Does Little to Benefit Protein Undernutrition in the Developing World

Some persons argue that the routine addition of antibiotics to animal feed will help alleviate protein undernutrition in developing countries by increasing meat production. In contrast, we estimate that, if all routine antibiotic use in animal feed were ceased, there would be negligible effects in these countries. Poultry and pork production are unlikely to decrease by more than 2%. Average daily protein supply would decrease by no more than 0.1 g per person (or 0.2% of total protein intake). Eliminating the routine use of in-feed antibiotics will improve human and animal health, by reducing the development and spread of antibiotic-resistant bacteri

Archaeological Investigations at the Ikirahak Site Raise Questions Concerning Taltheilei Land Use in Southern Nunavut

We report a new Taltheilei site-type found off the west coast of Hudson Bay in southern Nunavut. The Taltheilei is an archaeological culture that existed in the Barrenlands of the central Canadian Subarctic between 2600 and 300 years ago. Their land use strategies were tethered to the seasonal migrations of the Beverly and Qamanirjuaq caribou herds throughout tundra and forest landscapes. Tundra-based sites are typically interpreted as short-lived summer camps, but our discovery of three unique pit-house sites on the shores of Maguse Lake raises new questions concerning diversity in Taltheilei tundra land use. Architectural, faunal, lithic, and geoarchaeological data recovered from the Ikirahak site (JjKs-7) support the hypothesis that Taltheilei groups were extending their tundra stays into the fall. We report the evidence from four excavated pit-house features. Terraced platforms along the internal perimeters of these houses suggest they were designed for cold season use. The faunal assemblage is dominated by caribou remains. Higher relative frequencies of appendicular elements suggest a focus on secondary butchering. A large fraction of the faunal assemblage is highly fragmented and calcined, which is consistent with heavy processing and the use of bone as an alternative fuel source. Higher frequencies of lithic debris around dwelling floor perimeters are suggestive of maintenance activities. Multi-element concentrations in dwelling and site-wide sediments also show that hearth refuse was dumped outside. These findings seem to reflect longer tundra occupations during fall, a land use strategy that was likely guided by Qamanirjuaq herd behaviour specific to the Maguse Lake area, fall hunting and processing goals, and ecologically couched mobility logistics. As just four pit-houses from one Taltheilei camp have been investigated to date, our understanding of these places within Taltheilei worlds and northern socio-ecologies is currently limited. Further research at Ikirahak, the other Maguse Lake pit-house sites, and at other caribou water crossings on the tundra of the Qamanirjuaq caribou range is needed to support or refute our hypotheses.Nous signalons un nouveau site de type taltheilei trouvé sur la côte ouest de la baie d’Hudson, dans le sud du Nunavut. La culture taltheilei est une culture archéologique qui a existé dans les landes de la zone subarctique centrale canadienne il y a de cela 2600 à 300 ans. Les stratégies d’utilisation des terres de cette culture étaient rattachées aux migrations saisonnières des hardes de caribous de Beverly et de Qamanirjuaq dans la toundra et la forêt. De manière générale, les sites trouvés dans la toundra sont interprétés comme des campements d’été de courte durée. Cependant, notre découverte de trois sites uniques de maisons semi-souterraines sur les rives du lac Maguse soulève de nouvelles questions au sujet de la diversité de l’utilisation de la toundra par les Taltheilei. Les données architecturales, fauniques, lithiques et géoarchéologiques recueillies au site d’Ikirahak soutiennent l’hypothèse selon laquelle les groupements de Taltheilei occupaient la toundra jusqu’à l’automne. Nous signalons des preuves en provenance de quatre aménagements de maisons semi-souterraines. Le long du périmètre interne de ces maisons, les plateformes en terrasses suggèrent qu’elles étaient conçues pour servir pendant la saison froide. Des restes de caribous dominent l’assemblage faunique. Des fréquences relatives plus élevées d’éléments appendiculaires laissent entrevoir que le dépeçage secondaire y occupait une grande place. Une grande fraction de l’assemblage faunique est fortement fragmentée et calcinée, ce qui correspond à une transformation importante et à l’utilisation des os comme source de combustible. Les grandes fréquences de débris lithiques entourant le périmètre des planchers d’habitations suggèrent des activités de maintenance. Les concentrations d’éléments multiples dans les sédiments des habitations et de l’ensemble du site indiquent également que les déchets des âtres étaient jetés à l’extérieur. Ces constatations laissent entrevoir de plus longues occupations de la toundra à l’automne, une stratégie d’utilisation des terres vraisemblablement guidée par le comportement propre à la harde de Qamanirjuaq dans la région du lac Maguse, par la chasse automnale et par les objectifs de transformation, de même que par la logistique de la mobilité en termes écologiques. Puisque seulement quatre maisons semi-souterraines d’un seul campement taltheilei ont été étudiées jusqu’à maintenant, nous comprenons toujours peu de choses au sujet de ces endroits dans le monde des Taltheilei et des socioécologies nordiques. Il y a lieu de pousser les recherches plus loin à Ikirahak, là où se trouvent les autres sites de maisons semi-souterraines du lac Maguse, ainsi qu’à d’autres passages de franchissement de l’eau sur la toundra du parcours des caribous de Qamanirjuaq afin de confirmer ou de réfuter nos hypothèses

SHOULD I STAY OR SHOULD I GO: THE ROLE OF REFERRALS ON ONLINE COMMUNITY MEMBER TURNOVER AND TENURE

Communities are often faced with challenges associated with attracting and maintaining a membership base, which affects their ability to develop a pool of resources and ultimately impacts their sustainability. A potential resolution to this challenge lies in the members of the community referring non-members to the community – member referrals. While community joining has been acknowledged as important stage in the life cycle of community members; however, the way in which a member becomes aware of a community and its resulting influence on their engagement with the community has not been examined. This research-in-progress paper outlines the examination of the role of referrals on member turnover and tenure. Drawing upon theories of referrals from organizational behavior and marketing, the paper theorizes that referrals have the potential to facilitate the awareness of, and interest in, a community, which ultimately influences new members to return to, and stay, in a community

Physiological Response to Feeding in Little Penguins

© 2006 by The University of Chicago.Specific dynamic action (SDA), the increase in metabolic rate above resting levels that accompanies the processes of digestion and assimilation of food, can form a substantial part of the daily energy budget of free-ranging animals. We measured heart rate (fH) and rate of oxygen consumption ( ) in 12 little penguins while they digested a meal of sardines in order to determine whether they show specific dynamic action. In contrast to some studies of other penguin species, little penguins showed a substantial SDA, the magnitude of which was proportional to the size of the meal. The energy utilized in SDA was equivalent to 13.4% of the available energy content of the fish. Furthermore, animals such as penguins that forage in a cold environment will probably expend further energy in heating their food to body temperature to facilitate efficient digestion. It is estimated that this additional energy expenditure was equivalent to 1.6%-2.3% of the available energy content of the fish, depending on the time of year and therefore the temperature of the water. Changes in fH during digestion were qualitatively similar to those in , implying that there were no substantial circulatory adjustments during digestion and that the relationship between fH and in penguins is unaffected by digestive state

The virtual pedagogy initiative

Contemporary Higher Education Institutions must adapt to address government funded calls for expansion and widened participation. The adoption of e-learning strategies, such as the use of the podcasts, can facilitate flexible learning around the needs and expectations of students. In this article we outline a number of e-learning developments at Aston University collectively referred to as the Virtual Pedagogy Initiative. Each of the strands, podcasts, vodcasts, mobile telephony and the campus wide remote broadcasts, are described pedagogically as well as technically. Where possible data highlighting the student response and experience are included. The article begins with the contention that contemporary undergraduates may be qualitatively different and can considered „digital natives?