Tobacco outlet density and demographics: analysing the relationships with a spatial regression approach.

OBJECTIVE: Studies of relationships between tobacco sales and socio-economic/sociodemographic characteristics are well documented. However, when analysing the data that are collected on geographic areas, the spatial effects are seldom considered, which could lead to potential misleading analytical results. This study addresses this concern by applying the spatial analysis method in studying how socio-economic factors and tobacco outlet density are related in New Jersey, USA. STUDY DESIGN: A spatial regression method applied to tobacco outlet and socio-economic data obtained in 2004 in New Jersey, USA. METHOD: This study assessed the association between tobacco outlet density and three demographic correlates - income, race and ethnicity - at the tract level of analysis for one state in the north-eastern USA. Data for 1938 residential census tracts in the state of New Jersey were derived from 2004 licences for 13,984 tobacco-selling retail outlets. Demographic variables were based on 2000 census data. When applying a regression model, the residuals of an ordinary least squared (OLS) estimation were found to exhibit strong spatial autocorrelation, which indicates that the estimates from the OLS model are biased and inferences based on the estimates might be misleading. A spatial lag model was employed to incorporate the potential spatial effects explicitly. RESULTS: Agreeing with the OLS residual autocorrelation test, the spatial lag model yields a significant coefficient of the added spatial effect, and fits the data better than the OLS model. In addition, the residuals of the spatial regression model are no longer autocorrelated, which indicates that the analysis produces more reliable results. More importantly, the spatial regression results indicate that tobacco companies attempt to promote physical availability of tobacco products to geographic areas with disadvantageous socio-economic status. In New Jersey, the percentage of Hispanics seems to be the dominant demographic factor associated with tobacco outlet distribution, followed by median household income and percentage of African Americans. CONCLUSION: This research applied a spatial analytical approach to assess the association between tobacco outlet density and sociodemographic characteristics in New Jersey at the census tract level. The findings support the common wisdom in the public health research domain that tobacco outlets are more densely distributed in socio-economically disadvantaged areas. However, incorporating the spatial effects explicitly in the analysis provides less biased and more reliable results than traditional methods.

Hydralazine-pyrimidine interactions may explain hydralazine-induced lupus erythematosus.

Hydralazine, the prototypic drug that induces systemic lupus erythematosus, reacts with thymidine and deoxycytidine. Analysis of a reaction mixture of therapeutic concentrations of hydralazine with labeled thymidine reveals at least four labeled products. At higher concentrations, hydralazine reacts with labeled deoxycytidine to form at least three labeled products. Formation of these products is markedly enhanced by exposure to ultraviolet light. The reaction of hydralazine with thymidine and deoxycytidine may be in part responsible for initiating drug-induced systemic lupus erythematosus.

Results from the Mars Pathfinder camera.

Images of the martian surface returned by the Imager for Mars Pathfinder (IMP) show a complex surface of ridges and troughs covered by rocks that have been transported and modified by fluvial, aeolian, and impact processes. Analysis of the spectral signatures in the scene (at 440- to 1000-nanometer wavelength) reveal three types of rock and four classes of soil. Upward-looking IMP images of the predawn sky show thin, bluish clouds that probably represent water ice forming on local atmospheric haze (opacity approximately 0.5). Haze particles are about 1 micrometer in radius and the water vapor column abundance is about 10 precipitable micrometers.

Bioaccumulation of persistent organic pollutants in female common dolphins (Delphinus delphis) and harbour porpoises (Phocoena phocoena) from western European seas: geographical trends, causal factors and effects on reproduction and mortality.

Concentrations of polychlorinated biphenyls (PCBs) in blubber of female common dolphins and harbour porpoises from the Atlantic coast of Europe were frequently above the threshold at which effects on reproduction could be expected, in 40% and 47% of cases respectively. This rose to 74% for porpoises from the southern North Sea. PCB concentrations were also high in southern North Sea fish. The average pregnancy rate recorded in porpoises (42%) in the study area was lower than in the western Atlantic but that in common dolphins (25%) was similar to that of the western Atlantic population. Porpoises that died from disease or parasitic infection had higher concentrations of persistent organic pollutants (POPs) than animals dying from other causes. Few of the common dolphins sampled had died from disease or parasitic infection. POP profiles in common dolphin blubber were related to individual feeding history while those in porpoises were more strongly related to condition.

Brucella ceti associated pathology in the testicle of a harbour porpoise (Phocoena phocoena).

Brucellosis is reported increasingly in marine mammals and the marine species of Brucella are capable of causing community acquired zoonotic infections in humans as well as abortion in cattle as a result of experimental infection. This case report describes pathology associated with an isolate of Brucella ceti that was successfully cultured from, and immunolabelled in, the testis and epididymis of an adult sexually mature free-living harbour porpoise (Phocoena phocoena). This is the first report of such pathology in any species of cetacean, and suggests the potential for sexual transmission and/or sterility as sequelae to infection similar to those reported in terrestrial animals.

Mass-dependent predation risk and lethal dolphin-porpoise interactions.

In small birds, mass-dependent predation risk (MDPR) is known to make the trade-off between avoiding starvation and avoiding predation dependent on individual mass. This occurs because carrying increased fat reserves not only reduces starvation risk but also results in a higher predation risk due to reduced escape flight performance and/or the increased foraging exposure needed to maintain a higher body mass. In principle, the theory of MDPR could also apply to any animal capable of storing energy reserves to reduce starvation and whose escape performance decreases with increasing mass. We used a unique situation along certain parts of coastal Britain, where harbour porpoises (Phocoena phocoena) are pursued and killed but crucially not eaten by bottlenose dolphins (Tursiops truncatus), to investigate whether a MDPR effect can occur in non-avian species. We show that where high levels of dolphin 'predation' occur, porpoises carry significantly less energy reserves than would otherwise be expected and this equates to reducing by approximately 37% the length of time that a porpoise could survive without feeding. These results provide the first evidence that a mass-dependent starvation-predation risk trade-off may be a general ecological principle that can apply to widely different animal types rather than, as is currently thought, only to birds.

Comparative contributions of solution geochemistry, microbial metabolism and aquatic photosynthesis to the development of high pH in ephemeral wetlands in South East Australia.

The development of alkaline conditions in lakes and wetlands is common but the process of alkalinisation is not well elaborated. In this study we investigated causes of the seasonal alkalinisation of ephemeral wetlands in the South East of South Australia where pH values above 10 are frequently observed. This research combined field observations, geochemical analysis of wetland sediment and surface water, with mesocosm studies under controlled conditions. The results revealed a complex interplay between a number of different processes. A primary cause was attributed to sequestration of CO2 from the water column by plant photosynthesis, coupled with slow diffusion of CO2 from the air which led to its depletion in the water. Abundant plant growth also modified the water chemistry via uptake of nutrient elements, in particular calcium and magnesium and increased carbonate alkalinity in the water. Assessment of field results and geochemical modeling showed that low Ca/(HCO3(-) and CO3(-2)) ratios in the water, coupled with carbonate mineral (calcite, Mg substituted calcite, dolomite) precipitation and evapoconcentration, create a high alkalinity and pH (>9) baseline in many wetlands. The high baseline pH is then further increased by CO2 depletion due to photosynthesis. We could find no evidence that reduction of sulfate to sulfides by sulfur-reducing bacteria significantly contributed to the very high pH conditions.

Yeast as a model organism for studying the actions of DNA topoisomerase-targeted drugs.

The budding yeast Saccharomyces cerevisiae has been exploited to investigate the cytotoxic mechanisms of drugs that target DNA topoisomerases. This model organism has been used to establish eukaryotic DNA topoisomerase I or II as the cellular target of specific antineoplastic agents, to define mutations in these enzymes that confer drug resistance and to elucidate the cellular factors that modulate cell sensitivity to DNA topoisomerase-targeted drugs. These findings have provided valuable insights into the critical activities of these enzymes and how perturbing their functions produces DNA damage and cell death.

Direct Evaluation of the Ca2+-Displacement Hypothesis for Al Toxicity.

One explanation for Al toxicity in plants suggests that Al displaces Ca2+ from critical sites in the apoplasm. We evaluated the Ca2+-displacement hypothesis directly using near-isogenic lines of wheat (Triticum aestivum L.) that differ in Al tolerance at a single locus. We measured both the growth and total accumulation (apoplasmic plus symplasmic) of 45Ca and Al into roots that had been exposed to Al alone or to Al with other cations. Root growth in the Al-sensitive line was found to be severely inhibited by low activities of Al, even though Ca2+ accumulation was relatively unaffected. In solutions containing the same activity of the Al3+ and Ca2+ ions as above, but also including either 3.0 mM Mg2+, 3.0 mM Sr2+, or 30 mM Na+, growth improved, whereas 45Ca2+ accumulation was significantly decreased. Since most of the 45Ca2+ accumulated by roots during short-term treatments will reside in the apoplasm, these results indicate that displacement of Ca2+ from the apoplasm by Al cannot account for the Al-induced inhibition of root growth and, therefore, do not support the Ca2+-displacement hypothesis for Al toxicity. We also show that total accumulation of Al by root apices is greater in the Al-sensitive genotype than the Al-tolerant genotype and suggest that cation amelioration of Al toxicity is caused by the reduction in Al accumulation.

NADPH:protochlorophyllide oxidoreductase from Synechocystis: overexpression, purification and preliminary characterisation.

NADPH:protochlorophyllide oxidoreductase (POR) catalyses the light-dependent reduction of protochlorophyllide to chlorophyllide, a key regulatory reaction in the chlorophyll biosynthetic pathway. POR from the cyanobacterium Synechocystis has been overproduced in Escherichia coli with a hexahistidine tag at the N-terminus. This enzyme (His(6)-POR) has been purified to homogeneity and a preliminary characterisation of its kinetic and substrate binding properties is presented. Chemical modification experiments have been used to demonstrate inhibition of POR activity by the thiol-specific reagent N-ethyl maleimide. Substrate protection experiments reveal that the modified Cys residues are involved in either substrate binding or catalysis.

Chemical modification of aminoglycosides. 3. Synthesis of 2"-deoxykanamycins from neamine.

The preparation of 2"-deoxykanamycin B (12) and 2",3',4'-trideoxykanamycin B (14) from neamine (1) is described. Key intermediates in the synthesis of these 2"-deoxyaminoglycoside antibiotics are 3',4'-bis-O-(p-nitrobenzoyl)-1,2',3,6'-tetrakis-N-(trifluoroacetyl)neamine (6) and 3',4'-dideoxy-1,2',3,6'-tetrakis-N-(trifluoroacetyl)neamine (9). The amino groups of these intermediates are blocked by the trifluoroacetyl group, a blocking group not widely used in aminoglycoside chemistry.

Gatekeeping and referral of children and adolescents to specialty care.

OBJECTIVE: In this study we examined how gatekeeping arrangements influence referrals to specialty care for children and adolescents in private and Medicaid insurance plans. DESIGN/PARTICIPANTS: We conducted a prospective study of office visits (n = 27 104) made to 142 pediatricians in 94 practices distributed throughout 36 states in a national primary care practice-based research network. During 10 practice-days, physicians and patients completed questionnaires on referred patients, while office staff kept logs of all visits. Physicians used medical records to complete questionnaires for a subset of patients 3 months after their referral was made. RESULTS: Gatekeeping arrangements were common among children and adolescents with private (57.8%) and Medicaid (43.3%) insurance. Patients in gatekeeping plans were more likely to be referred with private (3. 16% vs 1.85% visits referred) and Medicaid (5.39% vs 3.73%) financing. Increased parental requests for specialty care among gatekeeping patients did not explain the increased referral rate. Physicians' reasons for making the referral were similar between the two groups. Physicians were less likely to schedule an appointment or communicate with the specialist for referred patients in gatekeeping plans. However, rates of physician awareness that a specialist visit occurred and specialist communication back to pediatricians did not differ between the two groups 3 months after the referrals were made. CONCLUSIONS: Gatekeeping arrangements are common among insured children and adolescents in the United States. Our study suggests that gatekeeping arrangements increase referrals from pediatricians' offices to specialty care and compromise some aspects of coordination.

Evidence for infanticide in bottlenose dolphins: an explanation for violent interactions with harbour porpoises?

Most harbour porpoises found dead on the north-east coast of Scotland show signs of attack by sympatric bottlenose dolphins, but the reason(s) for these violent interactions remain(s) unclear. Post-mortem examinations of stranded bottlenose dolphins indicate that five out of eight young calves from this same area were also killed by bottlenose dolphins. These data, together with direct observations of an aggressive interaction between an adult bottlenose dolphin and a dead bottlenose dolphin calf, provide strong evidence for infanticide in this population. The similarity in the size range of harbour porpoises and dolphin calves that showed signs of attack by bottlenose dolphins suggests that previously reported interspecific interactions could be related to this infanticidal behaviour. These findings appear to provide the first evidence of infanticide in cetaceans (whales, dolphins and porpoises). We suggest that infanticide must be considered as a factor shaping sociality in this and other species of cetaceans, and may have serious consequences for the viability of small populations.

Synthesis of acetylenic cyclophanes via intramolecular self-assembly: evidence of perfluorophenyl-phenyl quadrupole interactions in the solution state.

Reported herein is an example of a solution-state cross-coupling cyclization with an outcome mediated by perfluorophenyl-phenyl electrostatic interactions.

A review of Brucella sp. infection of sea mammals with particular emphasis on isolates from Scotland.

Brucellae recovered from sea mammals were first reported in 1994. In the years since both culture and serological analysis have demonstrated that the infection occurs in a wide range of species of marine mammals inhabiting a vast amount of the world's oceans. Molecular studies have demonstrated that the isolates differ from those found amongst terrestrial animals and also distinguish between strains which have seals and cetaceans as their preferred hosts. At the phenotypic level seal and cetacean strains can also be differed with respect to their CO(2) requirement, primary growth on Farrells medium and metabolic activity on galactose. Two new species B. cetaceae and B. pinnipediae have been proposed as a result. This paper provides a review of Brucella in sea mammals and updates findings from the study of sea mammals from around the coast of Scotland.

Concentrations and patterns of organic contaminants in Atlantic white-sided dolphins (Lagenorhynchus acutus) from Irish and Scottish coastal waters.

Chlorobiphenyls (CBs) and organochlorine pesticides (OCPs) have been determined in the blubber of 17 Atlantic white-sided dolphins stranded at Killala Bay, Co Mayo, Ireland and five from the Scottish coast. The concentrations of the contaminants measured range from 773 to 63,400 microg kg(-1) for sigmaCB and from 160 to 54,600 microg kg(-1) for sigmaDDT. The concentrations of the CBs and OCPs is highly dependent on the age, sex, reproductive state and nutritional condition of the animals in addition to the intake via the food web. Principal Components Analysis (PCA) has been used to study the variation of chemical patterns (data ratioed to CB 153). Immature animals (< 6 years), mature males and primogravid females, and lactating females could be distinguished on the basis of their contaminant patterns. This paper describes the different processes of bioaccumulation and metabolism of organochlorine contaminants (OCs) in this species.

Chronic meningoencephalitis associated with Brucella sp. infection in live-stranded striped dolphins (Stenella coeruleoalba).

A chronic, non-suppurative meningoencephalitis was found in three young striped dolphins (Stenella coeruleoalba) during routine neuropathological examination of marine mammals live-stranded on the Scottish coast. In all three dolphins the lesions were associated with the isolation of a Brucella sp. from the brain and with the immunohistochemical detection of brucella antigen. Moreover, antibodies to Brucella spp. were detected in the two dolphins that were subjected to serological examination. Immunohistochemical and serological examinations for morbillivirus antigen and antibodies, respectively, were negative in all cases. Although brucella infection of marine mammals has been extensively documented in recent years, its association with lesions and disease is less well recognized. The present report provides the first description of an association between Brucella sp. infection and neuropathological changes in a cetacean species.

Isolation of Brucella species from cetaceans, seals and an otter.

Brucella organisms which differed from the recognised species of the genus, were isolated from nine seals, eight cetaceans and one otter. A method is described for the isolation of Brucella species from sea mammals and the first isolations of Brucella species are recorded from an Atlantic white-sided dolphin (Lagenorhynchus acutus), two striped dolphins (Stenella coeuleoalba), a hooded seal (Cystophora cristata), a grey seal (Halichoerus grypus) and a European otter (Lutra lutra). There were differences in the culture media required for the primary isolation of the organisms and in their dependency on carbon dioxide, Subcutaneous lesions, when present, always yielded a confluent growth. The organisms were isolated from seven of 14 spleen samples and also from the mammary glands, uterus, testes and blood and the mandibular, gastric, iliac, sub-lumbar and colorectal lymph nodes.