MalariaSphere: A greenhouse-enclosed simulation of a natural Anopheles gambiae (Diptera: Culicidae) ecosystem in western Kenya

Background  

The development and implementation of innovative vector control strategies for malaria control in Africa requires in-depth ecological studies in contained semi-field environments. This particularly applies to the development and release of genetically-engineered vectors that are refractory to Plasmodium infection. Here we describe a modified greenhouse, designed to simulate a natural Anopheles gambiae Giles ecosystem, and the first successful trials to complete the life-cycle of this mosquito vector therein.     

Empty Nest: A Case Study of Maternal Response to Separation From a Juvenile Offspring in a Captive Sumatran Orangutan (Pongo pygmaeus abelii)

Improving the welfare of captive nonhuman primates requires evaluating the stressors created by the captive environment and reducing their negative effects. Social separation, although sometimes necessary for managing the genetic diversity of captive populations of animals, causes both psychological and physiological stress in human and primate monkey infants. Few studies have examined the maternal response of great ape mothers to separation from their offspring. This article describes the behavioral changes of a mother orangutan (Pongo pygmaeus abelii) after separation from her juvenile daughter. We collected data on measures of proximity and social behavior before the separation of the mother-infant dyad and of locomotion, arboreality, abnormal behavior, solitary behavior, and vocalization both before and after separation. We observed no behavioral indications of protest but observed some indications of despair after separation: decreased locomotion, increased inactivity, and increased self-directed behavior. In addition, we observed increases in arboreality and object-oriented behavior during morning sessions. These findings suggest that mother-juvenile separation in orangutans might be less stressful for mothers than might be expected. Such research has implications for the welfare and management of captive animals.     

To hunt or not to hunt? A feeding enrichment experiment with captive large felids

It is often difficult to promote the successful performance of feeding behaviors in zoos, especially for carnivores. Feeding enrichment provides these opportunities and often improves behavioral indications of an animal's well‐being and the experience of the zoo visitor. The effectiveness of two different feeding enrichment techniques was evaluated on five subjects in two species of felids: African lions and Sumatran tigers. The activity budgets of each cat were compared before, during, and after enrichment, focusing on activity levels, frequency and variety of feeding behaviors, and occurrence of stereotypic behaviors. The presentation of live fish increased the variety and frequency of feeding behaviors, while presentation of horse leg bones increased the frequency of these behaviors. Fish reduced the tigers' stereotypic behavior from 60% of scans to 30% of scans on the day of presentation, and this change was maintained for 2 days following enrichment. Bone presentation also reduced stereotypic behavior and increased nonstereotypic activity in both species. Both of these techniques appear to have sustained effects on behavior lasting at least 2 days after presentation, which may indicate their ability to alter the animals' underlying activity patterns. Zoo Biol 22:189–198, 2003. © 2003 Wiley‐Liss, Inc.     

Radiation biology of mosquitoes

There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT) to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal stage was irradiated due to ease of handling compared to the adult stage. The dose-response curve between the induced sterility and log (dose) was shown to be sigmoid, and there was a marked species difference in radiation sensitivity. Mating competitiveness studies have generally been performed under laboratory conditions. The competitiveness of males irradiated at high doses was relatively poor, but with increasing ratios of sterile males, egg hatch could be lowered effectively. Males irradiated as pupae had a lower competitiveness compared to males irradiated as adults, but the use of partially-sterilizing doses has not been studied extensively. Methods to reduce somatic damage during the irradiation process as well as the use of other agents or techniques to induce sterility are discussed. It is concluded that the optimal radiation dose chosen for insects that are to be released during an SIT programme should ensure a balance between induced sterility of males and their field competitiveness, with competitiveness being determined under (semi-) field conditions. Self-contained ⁶⁰Co research irradiators remain the most practical irradiators but these are likely to be replaced in the future by a new generation of high output X ray irradiators.     

Caerulein secretion by dermal glands in xenopus laevis

Since gastrin and its related peptides are secreted by a minority population of widely dispersed cells in mamamalian tissues it has, in the past, been difficult to study the subcellular aspects of their secretion. From published reports (1, 2) it seemed possible that a satisfactory system for such studies might be provided by the skin of certain amphibians such as Xenopus laevis since in these tissues high concentrations of peptides such as caerulein exist, and there is some indication (3) that this, or a similar gastrin-like peptide, may be a dermal gland secretory product. We have therefore explored this possibility by studying the structure, secretory process, and secretory product of the most prominent non mucous type of gland in the skin of X. laevis. These studies clearly demonstrate that most, if not all, of the caerulein in which the skin is contained in secretion granules within the dermal glands and that its release can be specifically evoked by adrenergic stimulation. The release process by a holocrine mechanism expels all of the stored secretion onto the skin surface and thus for biosynthetic studies it should now be possible to synchronize the processes which lead to the replenishment of the peptide.     

Nonfatal childhood injuries: a survey at the Children's Hospital of eastern Ontario.

OBJECTIVE: To examine the types and severity of injuries seen in the Emergency Department of the Children''s Hospital of Eastern Ontario and the circumstances surrounding the events. DESIGN: Chart review. SETTING: A tertiary care hospital that serves a child population of 600,000 in eastern Ontario and western Quebec. PARTICIPANTS: Every sixth day''s charts of children up to 17 years of age who visited the Emergency Department because of injuries between Sept. 1, 1984, and Aug. 31, 1985, were examined retrospectively. RESULTS: A total of 2886 charts were reviewed. There were more boys than girls. Most (1354 [46.9%]) of the accidents had occurred at home. Falls and sports-related accidents were the leading causes of injury (in 1088 [37.7%] and 560 [19.4%] of the cases respectively). Most of the visits were for minor injuries (bumps, swellings, cuts, bruises and scrapes), and only 114 (4.0%) of the children were admitted to the hospital. Injuries from motor vehicle accidents accounted for the highest admission rate (17.4%). Important information regarding the circumstances surrounding the events (e.g., whether a seat belt or car seat was used) was frequently missing from the charts. CONCLUSIONS: Nonfatal injuries are common, especially in or around the home, and remain a significant problem in our society in terms of radiographic and consulting fees, time off from school or work and pain. Given the difficulties in obtaining information on the circumstances surrounding the events prospective studies are needed. Factors related to the occurrence and severity of childhood injury and whether these factors can be altered remain a high priority for research.     

Confirmation of quantitative trait loci affecting fatness in chickens

In this report we describe the analysis of an advanced intercross line (AIL) to confirm the quantitative trait locus (QTL) regions found for fatness traits in a previous study. QTL analysis was performed on chromosomes 1, 3, 4, 15, 18, and 27. The AIL was created by random intercrossing in each generation from generation 2 (G₂) onwards until generation 9 (G₉) was reached. QTL for abdominal fat weight (AFW) and/or percentage abdominal fat (AF%) on chromosomes 1, 3 and 27 were confirmed in the G₉ population. In addition, evidence for QTL for body weight at the age of 5 (BW5) and 7 (BW7) weeks and for the percentage of intramuscular fat (IF%) were found on chromosomes 1, 3, 15, and 27. Significant evidence for QTL was detected on chromosome 1 for BW5 and BW7. Suggestive evidence was found on chromosome 1 for AFW, AF% and IF%, on chromosome 15 for BW5, and on chromosome 27 for AF% and IF%. Furthermore, evidence on the chromosome-wise level was found on chromosome 3 for AFW, AF%, and BW7 and on chromosome 27 for BW5. For chromosomes 4 and 18, test statistics did not exceed the significance threshold.