The application of island-biogeographic theory to patches of habitat: How much land is enough?

The problem of estimating the minimum-sized parcel of land needed to preserve a given suite of species is little-addressed. Two techniques available for such estimations are: (1) ‘the method of island biogeography’, which uses extrapolations of the species-area equation; and (2) ‘the method of addition’, which uses only the actual suite of ‘island’ under investigation. No rationale exists for choosing technique 1 a priori, although the choice is often made. The two techniques produce minimum area estimates which define a spectrum of potential minimum areas. Determination of the real minimum area requirement must rely upon detailed natural-historical observation.     

Effects of airborne emissions from a natural gas processing plant on the production of swine

Specific-pathogen-free swine were produced under field conditions in a high emission exposure area and a low emission exposure area of a natural gas processing plant over a period of 38 mo. Production parameters were measured and respiratory tissues sampled. Sulfur dioxide concentration was monitored in the high exposure area. Average concentrations of SO₂ exceeded 0.20 ppm for 30 min on 23 occasions during one of four rate of gain and feed conversion trials. Average concentrations of SO₂ exceeded 0.02 ppm for 24 hr on 5 days when farrowings occurred. No significant difference was found in rate of gain, feed conversion, piglets born per litter or piglet survival, between swine produced in the two areas. No histological a alterations such as loss of cilia, atrophy of goblet cells or cellular metaplasia were observed in any respiratory epithelia from 62 pigs.     

Mariculture potential of the spot prawn, Pandalus platyceros Brandt

Biological characteristics and culture methods were investigated for the spot prawn, Pandalus platyceros Brandt. Ovigerous adults were caught in the local fishery; six of these produced 2 628 to 4 669 larvae. The larval period ranged from 26 to 35 days (9.5–12.0°C). Maximum larval survival was about 70%, with mortalities being most frequent during ecdysis. The relation of wet weight (g) to carapace length (mm) for the first 26 months was calculated as log W = ?3.0843 + 2.9308 log L. Prawns showed good survival between 9.5 and 21.0°C. Mortality increased sharply when temperatures exceeded 21.0°C. Salinities below 22‰ resulted in a sharp increase in mortality.A diet of brine shrimp nauplii sufficed for newly hatched larvae. Growth was enhanced when larvae were fed a unicellular algal supplement (Phaeodactylum tricornutum), although mortality was somewhat higher. Larvae progressed rapidly to foraging on larger brine shrimp and diced foods. Six-month-old spot prawns raised on a squid diet averaged 3.4 g, and at 1 year the mean weight was 6.3 g. A feeding experiment, incorporating 12 diets, disclosed that highest growth rates and best food conversion ratios were achieved on a combined California seamussel and giant red sea urchin diet. However, the best growth rate achieved was considered marginal for mariculture.It was concluded that unless the growth rate could be accelerated by other food formulations or culture techniques, a monoculture system for mass cultivation would not be feasible. The spot prawn may have potential in a polyculture system.     

PNEUMATOSIS COLI IN A DOG

The extensive presence of air in the submucosal area of the colon was observed on abdominal radiographs of a one-year-old female Maltese. The diagnosis of pneumatosis cystoides intestinalis (pneumatosis coli when localized to the colon) is made when radiographs demonstrate submucosal or subserosal gas accumulation of the intestinal tract. The condition usually resolves spontaneously, but the potential for complications is present.     

T-lymphocyte priming and protection against Friend leukemia by vaccinia-retrovirus env gene recombinant

The current prevalence of the acquired immune deficiency syndrome in humans has provoked renewed interest in methods of protective immunization against retrovirus-induced diseases. In this study, a vaccinia-retrovirus recombinant vector was constructed to study mechanisms of immune protection against Friend virus leukemia in mice. The envelope (env) gene from Friend murine leukemia virus (F-MuLV) was inserted into the genome of a vaccinia virus expression vector. Infected cells synthesized gp85, the glycosylated primary product of the env gene. Processing to gp70 and p15E, and cell surface localization, were similar to that occurring in cells infected with F-MuLV. Mice inoculated with live recombinant vaccinia virus had an envelope-specific T-cell proliferative response and, after challenge with Friend virus complex, developed neutralizing antibody and cytotoxic T cells (CTL) and were protected against leukemia. In contrast, unimmunized and control groups developed a delayed neutralizing antibody response, but no detectable CTL, and succumbed to leukemia. Genes of the major histocompatibility complex influenced protection induced by the vaccinia recombinant but not that induced by attenuated N-tropic Friend virus.     

Control of a mucosal challenge and prevention of AIDS by a multiprotein DNA/MVA vaccine

Heterologous prime/boost regimens have the potential for raising high levels of immune responses. Here we report that DNA priming followed by a recombinant modified vaccinia Ankara (rMVA) booster controlled a highly pathogenic immunodeficiency virus challenge in a rhesus macaque model. Both the DNA and rMVA components of the vaccine expressed multiple immunodeficiency virus proteins. Two DNA inoculations at 0 and 8 weeks and a single rMVA booster at 24 weeks effectively controlled an intrarectal challenge administered 7 months after the booster. These findings provide hope that a relatively simple multiprotein DNA/MVA vaccine can help to control the acquired immune deficiency syndrome epidemic.     

The giant squid Architeuthis: An emblematic invertebrate that can represent concern for the conservation of marine biodiversity

The current public perception is that there is little reason for concern for the conservation of marine invertebrates, in part due to the scarcity of emblematic species to represent that diverse group. This paper shows that giant squid can be considered an emblematic species to represent concern for the conservation of marine invertebrate biodiversity because it satisfies all the requirements of an emblematic species. It shows that Architeuthis attracts public interest and attention and can serve as an indicator of oceanographic conditions and ocean climate change. It asserts that Architeuthis can represent concerns for vulnerable marine ecosystems associated with submarine canyons and that it belongs to a broad diverse phylogenetic group of organisms associated with these canyons, sharing common concerns with that group with respect to vulnerability and conservation. This study also advocates that the giant squid can serve as an indicator of effects of ecosystem stress resulting from anthropogenic effects including ocean acidification and warming. It is also shown to be vulnerable to such anthropogenic effects as fishing, acoustic seismic exploration and, possibly, pollutants.     

Group 1 and 2 Dermatophagoides house dust mite allergens in the microenvironment of cats

House dust mite allergens (HDMAs) are some of the most common allergens associated with allergic diseases in humans and dogs. The purpose of this study was to determine whether HDMAs could be detected in cat‐associated household microenvironments. From 50 cat‐only households with 95 cats, dust samples were collected by vacuuming for 2 min m^?2 from three areas where cats slept or rested regularly from September to October 2006. Relative humidity and temperature were measured in each household using a data logger. Each owner completed a questionnaire on potential factors that might influence the prevalence of house dust mites (HDMs). Dust samples were analysed utilizing an ELISA for Der p 1, Der f 1 and HDM group 2 allergens. In 38 of 50 households there was greater than 2 μg g^?1 of dust for at least one HDMA. Using stepwise logistic regression, factors associated with increased HDMA levels included: free‐standing houses, number of humans in household, longhaired cats and age of the cat. Factors associated with decreased HDMA concentrations included: forced air heating and central air conditioning, less than 50% carpeting of the home, use of flea control, cats suffering from dermatological disease and the average temperature of the household. Many sleeping/resting areas utilized by cats contain sufficiently high levels of HDMAs to be potential sources of sensitization. This finding should lead to further determination of the role of HDMs in cats suffering from putative allergic conditions such as atopic dermatitis or asthma.     

Top-down versus bottom-up control of attention in the prefrontal and posterior parietal cortices

Attention can be focused volitionally by "top-down" signals derived from task demands and automatically by "bottom-up" signals from salient stimuli. The frontal and parietal cortices are involved, but their neural activity has not been directly compared. Therefore, we recorded from them simultaneously in monkeys. Prefrontal neurons reflected the target location first during top-down attention, whereas parietal neurons signaled it earlier during bottom-up attention. Synchrony between frontal and parietal areas was stronger in lower frequencies during top-down attention and in higher frequencies during bottom-up attention. This result indicates that top-down and bottom-up signals arise from the frontal and sensory cortex, respectively, and different modes of attention may emphasize synchrony at different frequencies.