Palladium-Catalyzed Carboxylative Coupling of Allylstannanes and allyl halides

A three-component carboxylative coupling between allyl halides, allylstannanes, and CO2 to produce allyl esters is catalyzed by Pd and Pt phosphine complexes. Allyl chloride and allyltributylstannane are thus converted to propenyl butenoate in excellent yield. Cross coupling of two different allyl components produces a nearly statistical mixture of all four possible esters. Tentative mechanistic pathways for the catalytic reaction are proposed

First Record of Ceratapsis monstrosa, a Larval Oceanic Penaeoid Crustacean, From the Gulf of Mexico

The genus Cerataspis (Gray, 1838) (Crustacea, Decapoda), assigned to the Penaeoidea by Burkenroad (1936) and Heegaard (1966), has circumglobal distribution between 40ºN and 40ºS (Morgan et al. 1985) and is represented in the Atlantic Ocean by two rarely collected species, C. monstrosa and C. petiti. Descriptions of both species are based on the larval forms since their adult form remain undescribed (Morgan et al. 1985). Although the larval development of Cerataspis is described by five mysis stages (I-V) (Heegaard 1966), the large larva is very un-mysid like and appears more like that of a megalops with the abdomen bend slightly toward the thorax. Other early developmental stages and life history aspects of Cerataspis are unknown. The bulky shape of the spectacular carapace with its various tubercles, horns, spines and large oil droplets contained in four pair of dorsal carapace tubercles most likely provide buoyancy for this pelagic life stage (Heegaard 1966, Morgan et al. 1985). Although larval Cerataspis, particularly the last three mysis stages, are typically pelagic, Heegaard (1966) suggested the adult form might be a reptant penaeoid which lives in the abyssal zone. Heegaard (1966) reported 41 specimens of Cerataspis (26 C. monstrosa; 15 C. petiti) by mysis larval stage. Nine of the C. monstrosa (six from plankton samples; three from stomach contents of dolphinfish (Coryphaena spp.) and 13 of the C. petiti (all from plankton collections) were reported from the Atlantic Ocean. Morgan et al. (1985) further provided analysis of an additional 240 specimens of Cerataspis collected during surveys conducted off the southeastern United States, including Batts (1972), Manooch et al. (1983), and Manooch and Mason (1984). One of those specimens was collected by plankton net, and all others were found in the stomach contents of either yellowfin tuna (Thunnus albacares), blackfin tuna (Thunnus atlanticus), skipjack tuna (Katsuwonus pelamis) or dolphinfish (Coryphaena hippurus). To date, assessment of plankton collections and food habits of pelagic fishes from the Atlantic Ocean, inclusive of the Gulf of Mexico (GOM) (Heegaard 1966, Morgan et al. 1985), has provided no records of Cerataspis from the GOM. We report the first record of C. monstrosa from the GOM, one collected by plankton net and two collected from the esophagus of a wahoo, Acanthocybium solandri

Palladium-Catalyzed Carboxylation of Allyl Stannanes and Carboxylative Coupling of Allyl Stannanes and Allyl Halides [Abstract]

The reaction of allyl stannanes with CO2 to form stannyl carboxylates (esters) is catalyzed by Pd(PR3)4 complexes. Thus, R3SnCH2CH=CH2 [R=Me and Ph]are converted to R3SnO2 CCH2CH=CH2 and R3SnO2CCH=CHCH3 under 33 atm of CO2 (70°C, THF) in moderate to excellent yield in the presence of 8 mol% Pd(PPh3)4 ; polycarboxylation of diallyldibutyltin and tetraallyltin also is effected, producing the respective di- and tetracarboxylates, Bu2Sn(O2CCH2CH=CH2)2 and Sn(O2CCH2 CH=CH2)4 , along with the corresponding isomeric crotyl derivatives. In the presence of allyl halides, allyl stannanes and CO2 undergo carboxylative coupling to produce allyl esters. Under these conditions other Sn-C (Sn-alkyl, -aryl, -vinyl) and Si-C (Si-allyl, -alkyl, -aryl, -vinyl) bonds are inert to carboxylation and carboxylative coupling with allyl halides. A tentative mechanism is proposed to account for this catalytic carboxylation of a main group metal-carbon bond

Occurrence of a Synchronous Hermaphroditic Striped Mullet, Mugil cephalus, from the Northern Gulf of Mexico

A synchronous hermaphroditic striped mullet, Mugil cephalus, was captured offshore of Southwest Pass, Louisiana on 6 December 1996 during the commercial roe mullet fishery harvest. The fish measured 412 mm FL, weighed 824 g and was determined to be 4 years old by otolith analysis. Gross examination of the gonads revealed four lobes: right and left ovaries and right and left testis which represents a unique occurrence among hermaphroditic fish. All lobes ended in a common sperm duct/oviduct with the exception of the left ovary which had no oviduct. Both ovaries contained vitellogenic oocytes and both testis had freely running spermatozoa. Histological examination showed many oocytes undergoing final oocyte maturation, the presence of some post ovulatory follicles and lobules full of tailed spermatozoa. There was no evidence of the intermingling of sperm and oocytes within the gonad. The capture of this fish on the spawning grounds and the advanced stage of both ovarian and testicular development suggests spawning probably would involve the release of both oocytes and spermatozoa

Prevention Research Centers: Contributions to Updating the Public Health Workforce Through Training

Because public health is a continually evolving field, it is essential to provide ample training opportunities for public health professionals. As a natural outgrowth of the Centers for Disease Control and Prevention\u27s Prevention Research Centers Program, training courses of many types have been developed for public health practitioners working in the field. This article describes three of the Prevention Research Center training program offerings: Evidence-Based Public Health, Physical Activity and Public Health for Practitioners, and Social Marketing. These courses illustrate the commitment of the Prevention Research Centers Program to helping create a better trained public health workforce, thereby enhancing the likelihood of improving public health

Framework for primary care organizations: the importance of a structural domain

Purpose. Conceptual frameworks for primary care have evolved over the last 40 years, yet little attention has been paid to the environmental, structural and organizational factors that facilitate or moderate service delivery. Since primary care is now of more interest to policy makers, it is important that they have a comprehensive and balanced conceptual framework to facilitate their understanding and appreciation. We present a conceptual framework for primary care originally developed to guide the measurement of the performance of primary care organizations within the context of a large mixed-method evaluation of four types of models of primary care in Ontario, Canada. Methods. The framework was developed following an iterative process that combined expert consultation and group meet-ings with a narrative review of existing frameworks, as well as trends in health management and organizational theory. Results. Our conceptual framework for primary care has two domains: structural and performance. The structural domain describes the health care system, practice context and organization of the practice in which any primary care organization operates. The performance domain includes features of health care service delivery and technical quality of clinical care. Conclusion. As primary care evolves through demonstration projects and reformed delivery models, it is important to evalu-ate its structural and organizational features as these are likely to have a significant impact on performance

The twilight of the Liberal Social Contract? On the Reception of Rawlsian Political Liberalism

This chapter discusses the Rawlsian project of public reason, or public justification-based 'political' liberalism, and its reception. After a brief philosophical rather than philological reconstruction of the project, the chapter revolves around a distinction between idealist and realist responses to it. Focusing on political liberalism’s critical reception illuminates an overarching question: was Rawls’s revival of a contractualist approach to liberal legitimacy a fruitful move for liberalism and/or the social contract tradition? The last section contains a largely negative answer to that question. Nonetheless the chapter's conclusion shows that the research programme of political liberalism provided and continues to provide illuminating insights into the limitations of liberal contractualism, especially under conditions of persistent and radical diversity. The programme is, however, less receptive to challenges to do with the relative decline of the power of modern states

Constitutivism

A brief explanation and overview of constitutivism

Social dynamics in nonbreeding flocks of a cooperatively breeding bird: causes and consequences of kin associations

Kin selection is regarded as a key process in the evolution of avian cooperative breeding, and kinship influences helper decisions in many species. However, the effect of kinship on nonbreeding social organization is still poorly understood despite its potential fitness implications. Here, we investigated the origins and consequences of kin associations in nonbreeding flocks of long-tailed tits, Aegithalos caudatus, an atypical cooperative breeder where helpers are failed breeders that redirect care towards relatives living in kin neighbourhoods. We found that kinship is an important factor in initial grouping decisions; all members of a nuclear family initially joined the same flock and failed breeders chose to flock with their relatives. Flocks that merged during the nonbreeding season also contained relatives. In contrast to these findings of positive kin association, when long-tailed tits switched flocks they tended to disperse into flocks with fewer relatives, although such switches often occurred with kin. In a playback experiment, we found no evidence that aggression shown towards members of other flocks was affected by kinship, indicating that kin associations result from a preference to flock with relatives rather than a constraint on flocking with nonrelatives. Finally, using social network analysis, we show that fine-scale nonbreeding associations among individuals were positively related to kinship, and that these nonbreeding associations were reflected in helping decisions in the subsequent breeding season, in addition to the previously reported effects of kinship and proximity. We conclude that long-tailed tits prefer to associate with kin when not breeding, and suggest that by doing so they gain either nepotistic benefits within flocks or future indirect benefits during breeding