Engorgement response of anopheline mosquitoes to blood fractions and artificial solutions

ABSTRACT. Anopheles stephensi Liston, Anopheles freeborni Aitken, Anopheles gambiae Giles and Anopheles dirus (Peyton & Harrison) fed equally well on whole blood, red blood cells, platelet-rich plasma and platelet-poor plasma. Similar feeding ability on 0.15 M NaCl containing 10^-2 M NaHCO₃ was shown by the first three species, but An. dirus required an addition of albumin. The need for ATP as a phagostimulant could not be demonstrated in any of these species.     

NARRATIVES OF ‘TERMINAL SEDATION’, AND THE IMPORTANCE OF THE INTENTION‐FORESIGHT DISTINCTION IN PALLIATIVE CARE PRACTICE

The moral importance of the ‘intention–foresight’ distinction has long been a matter of philosophical controversy, particularly in the context of end‐of‐life care. Previous empirical research in Australia has suggested that general physicians and surgeons may use analgesic or sedative infusions with ambiguous intentions, their actions sometimes approximating ‘slow euthanasia’. In this paper, we report findings from a qualitative study of 18 Australian palliative care medical specialists, using in‐depth interviews to address the use of sedation at the end of life. The majority of subjects were agnostic or atheistic. In contrast to their colleagues in acute medical practice, these Australian palliative care specialists were almost unanimously committed to distinguishing their actions from euthanasia. This commitment appeared to arise principally from the need to maintain a clear professional role, and not obviously from an ideological opposition to euthanasia. While some respondents acknowledged that there are difficult cases that require considered reflection upon one's intention, and where there may be some ‘mental gymnastics,’ the nearly unanimous view was that it is important, even in these difficult cases, to cultivate an intention that focuses exclusively on the relief of symptoms. We present four narratives of ‘terminal’ sedation – cases where sedation was administered in significant doses just before death, and may well have hastened death. Considerable ambiguities of intention were evident in some instances, but the discussion around these clearly exceptional cases illustrates the importance of intention to palliative care specialists in maintaining their professional roles.     

EFFECT OF HEALTH CONCERN AND CONSUMPTION PATTERNS ON MEASURES OF SWEETNESS BY HEDONIC AND JUST-ABOUT-RIGHT SCALES

An established disparity between hedonic scales and just-about-right (JAR) measures, important for product development procedures, was examined for sweetness in lemonade by consumer groups divided on the basis of health concern level and consumption patterns related to sweet foods, regular and diet drinks and 'healthy eating'. The disparity was demonstrated by all subgroups in that the JAR scale identified a lower sucrose concentration as nearest 'just right'compared to that identified as 'most liked'by the hedonic scale. Regression analysis predicted lower optimum sweetness for the JAR than the hedonic scale. For subjects who completed both tests the disparity was significantly different from zero. Trends of differences in response on both scales and for the disparity according to health concern and consumption patterns were demonstrated graphically. Few of these effects were statistically significant, but the differences in disparity level could justify market segmentation of drink products with different sucrose levels.     

Peroxisomal APX knockdown triggers antioxidant mechanisms favourable for coping with high photorespiratory H2O2 induced by CAT deficiency in rice

The physiological role of peroxisomal ascorbate peroxidases (pAPX) is unknown; therefore, we utilized pAPX4 knockdown rice and catalase (CAT) inhibition to assess its role in CAT compensation under high photorespiration. pAPX4 knockdown induced co‐suppression in the expression of pAPX3. The rice mutants exhibited metabolic changes such as lower CAT and glycolate oxidase (GO) activities and reduced glyoxylate content; however, APX activity was not altered. CAT inhibition triggered different changes in the expression of CAT, APX and glutathione peroxidase (GPX) isoforms between non‐transformed (NT) and silenced plants. These responses were associated with alterations in APX, GPX and GO activities, suggesting redox homeostasis differences. The glutathione oxidation‐reduction states were modulated differently in mutants, and the ascorbate redox state was greatly affected in both genotypes. The pAPX suffered less oxidative stress and photosystem II (PSII) damage and displayed higher photosynthesis than the NT plants. The improved acclimation exhibited by the pAPX plants was indicated by lower H₂O₂ accumulation, which was associated with lower GO activity and glyoxylate content. The suppression of both pAPXs and/or its downstream metabolic and molecular effects may trigger favourable antioxidant and compensatory mechanisms to cope with CAT deficiency. This physiological acclimation may involve signalling by peroxisomal H₂O₂, which minimized the photorespiration.     

Corymbia leaf oils,latitude, hybrids and herbivory: A test using common‐garden field trials

Foliar oils, particularly monoterpenes, can influence the susceptibility of plants to herbivory. In plants, including eucalypts, monoterpenes are often associated with plant defence. A recent analysis revealed an increase in foliar oil content with increasing latitudinal endemism, and we tested this pattern using three eucalypt taxa comprising a latitudinal replacement cline. We also examined the relative concentrations of two monoterpenes (α‐pinene and 1,8‐cineole), for which meta‐analyses also showed latitudinal variation, using hybrids of these three taxa with Corymbia torelliana. These, and pure C. torelliana, were then assessed in common‐garden field plots for the abundance and distribution of herbivory by four distinct herbivore taxa. Differing feeding strategies among these herbivores allowed us to test hypotheses regarding heritability of susceptibility and relationships to α‐pinene and 1,8‐cineole. We found no support for an increase in foliar oil content with increasing latitude, nor did our analysis support predictions for consistent variation in α‐pinene and 1,8‐cineole contents with latitude. However, herbivore species showed differential responses to different taxa and monoterpene contents. For example, eriophyid mites, the most monophagous of our censused herbivores, avoided the pure species, but fed on hybrid taxa, supporting hypotheses on hybrid susceptibility. The most polyphagous herbivore (leaf blister sawfly Phylacteophaga froggatti) showed no evidence of response to plant secondary metabolites, while the distribution and abundance patterns of Paropsis atomaria showed some relationship to monoterpene yields.     

Effects of Landscape Composition on Winter Survival of Northern Bobwhites

Abstract: In a manipulative experiment, we tested effects of select elements of landscape structure and composition on winter survival of northern bobwhites (Colinus virginianus) at Ames Plantation, Tennessee, USA. We hypothesized that abundance of closed canopy forested habitats (52% of the landscape) on Ames diminished usable space for bobwhite and provided usable space for a suite of important predators, thereby contributing to low winter survival. To test this hypothesis we divided a 2,217-ha portion of the property into 4 approximately equal areas. We altered landscape structure and composition by converting approximately 33% of the timber to early successional herbaceous plant communities on 2 treatment sites, which reduced percentage of landscape and edge density of closed canopy forest and increased percentage of landscape in early successional herbaceous communities, and left 2 control sites in their former composition. During one pretreatment year (1998–1999) and 3 posttreatment years (1999–2000, 2000–2001, 2001–2002), we estimated winter (15 Oct-10 Apr) survival on treatment and control sites from a radiomarked sample of 920 bobwhites. We used Cox Proportional Hazard models to test for effects of treatment (forest conversion) and covariates describing landscape structure and composition (% closed canopy forest, % early successional herbaceous, wooded edge density) on winter survival at multiple spatial scales. Winter survival on the treatment sites pooled across the 4 winter seasons was 41% compared to 32% for control sites. Additionally, for each 1 m/ha increase in closed canopy woods edge density within winter covey ranges, risk of mortality increased 0.3%. Our results suggest composition at the landscape scale and landscape structure at the local scale influence winter survival of bobwhite. Management strategies that alter composition and structure and increase usable space may be effective in mitigating winter mortality thereby altering population trajectories. Typical bobwhite management plans focus on improving quality of herbaceous vegetation structure within existing herbaceous patches, however, population processes may work at larger spatial scales influencing design and implementation of conservation programs.     

Scale-independent criteria and scale-dependent agents determining the structure of a ground cricket mosaic hybrid zone (Allonemobius socius – Allonemobius fasciatus)

The structure of the hybrid zone between the ground crickets, Allonemobius socius and Allonemobius fasciatus , approximates an environmental mosaic based on temperature/moisture at regional spatial scales. In the present study, we show that the micro-geographic spatial structure (i.e. single fields) of this hybrid zone is governed by the same criteria. Thus, the criteria that structure this hybrid zone are scale independent, even though the agents that implement these criteria may differ at various scales (climate, latitude, and elevation at regional scales; grass height, slope aspect, and field use at micro-geographic scales). Additionally, the study demonstrates a previously unknown barrier to genetic exchange in this system that acts before conspecific sperm precedence.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 777–796.     

The influence of the ability to disperse on generation length and population size in the flour beetle, Tribolium castaneum

Abstract.

• 1 In Tribolium castaneum Herbst, in which dispersal is genetically determined, it is possible to select for strains that are characterized by high and low dispersal, High dispersal (HD) beetles are better adapted than low dispersal (LD) beetles for colonization, as can be seen from differences that exist between the two groups with regard to several life-history parameters.
• 2 Comparisons were made between the dynamics of seventy-two HD and seventy-two LD populations. Generation length in HD populations was significantly shorter than in LD populations. After 9¹/₂ weeks, in open treatments (from which dispersal away from the set was allowed), HD populations had more beetles than LD populations, whereas in closed treatments (from which dispersal away from the set was not allowed) the opposite was true.
• 3 These findings may explain the maintenance of the genetic variability of dispersal behaviour in natural populations of T.castmeurn.