The pheromones of laying workers in two honeybee sister species: Apis cerana and Apis mellifera.

When a honeybee colony loses its queen, workers activate their ovaries and begin to lay eggs. This is accompanied by a shift in their pheromonal bouquet, which becomes more queen like. Workers of the Asian hive bee Apis cerana show unusually high levels of ovary activation and this can be interpreted as evidence for a recent evolutionary arms race between queens and workers over worker reproduction in this species. To further explore this, we compared the rate of pheromonal bouquet change between two honeybee sister species of Apis cerana and Apis mellifera under queenright and queenless conditions. We show that in both species, the pheromonal components HOB, 9-ODA, HVA, 9-HDA, 10-HDAA and 10-HDA have significantly higher amounts in laying workers than in non-laying workers. In the queenright colonies of A. mellifera and A. cerana, the ratios (9-ODA)/(9-ODA + 9-HDA + 10-HDAA + 10-HDA) are not significantly different between the two species, but in queenless A. cerana colonies the ratio is significant higher than in A. mellifera, suggesting that in A. cerana, the workers' pheromonal bouquet is dominated by the queen compound, 9-ODA. The amount of 9-ODA in laying A. cerana workers increased by over 585% compared with the non-laying workers, that is 6.75 times higher than in A. mellifera where laying workers only had 86% more 9-ODA compared with non-laying workers.

Reproductive biology of the Cape honeybee: a critique of Beekman et al.

Laying workers of the Cape honeybee parthenogenetically produce female offspring, whereas queens typically produce males. Beekman et al. confirm this observation, which has repeatedly been reported over the last 100 years including the notion that natural selection should favor asexual reproduction in Apis mellifera capensis. They attempt to support their arguments with an exceptionally surprising finding that A. m. capensis queens can parthenogenetically produce diploid homozygous queen offspring (homozygous diploid individuals develop into diploid males in the honeybee). Beekman et al. suggest that these homozygous queens are not viable because they did not find any homozygous individuals beyond the third larval instar. Even if this were true, such a lethal trait should be quickly eliminated by natural selection. The identification of sex (both with molecular and morphological markers) is possible but notoriously difficult in honeybees at the early larval stages. Ploidy is however a reliable indicator, and we therefore suggest that these "homozygous" larvae found in queen cells are actually drones reared from unfertilized eggs, a phenomenon well known by honeybee queen breeders.

An experiment on comb orientation by honey bees (Hymenoptera: Apidae) in traditional hives.

The orientation of combs in traditional beehives is extremely important for obtaining a marketable honey product. However, the factors that could determine comb orientation in traditional hives and the possibilities of inducing honey bees, Apis mellifera (L.), to construct more desirable combs have not been investigated. The goal of this experiment was to determine whether guide marks in traditional hives can induce bees to build combs of a desired orientation. Thirty-two traditional hives of uniform dimensions were used in the experiment. In 24 hives, ridges were formed on the inner surfaces of the hives with fermented mud to obtain different orientations, circular, horizontal, and spiral, with eight replicates of each treatment. In the remaining eight control hives, the inner surface was left smooth. Thirty-two well-established honey bee colonies from other traditional hives were transferred to the prepared hives. The colonies were randomly assigned to the four treatment groups. The manner of comb construction in the donor and experimental hives was recorded. The results showed that 22 (91.66%) of the 24 colonies in the treated groups built combs along the ridges provided, whereas only 2 (8.33%) did not. Comb orientation was strongly associated with the type of guide marks provided. Moreover, of the 18 colonies that randomly fell to patterns different from those of their previous nests, 17 (94.4%) followed the guide marks provided, irrespective of the comb orientation type in their previous nest. Thus, comb orientation appears to be governed by the inner surface pattern of the nest cavity. The results suggest that even in fixed-comb hives, honey bees can be guided to build combs with orientations suitable to honey harvesting, without affecting the colonies.

Comb construction in mixed-species colonies of honeybees, Apis cerana and Apis mellifera.

Comb building in mixed-species colonies of Apis cerana and Apis mellifera was studied. Two types of cell-size foundation were made from the waxes of these species and inserted into mixed colonies headed either by an A. cerana or an A. mellifera queen. The colonies did not discriminate between the waxes but the A. cerana cell-size foundation was modified during comb building by the workers of both species. In pure A. cerana colonies workers did not accept any foundation but secreted wax and built on foundation in mixed colonies. Comb building is performed by small groups of workers through a mechanism of self-organisation. The two species cooperate in comb building and construct nearly normal combs but they contain many irregular cells. In pure A. mellifera colonies, the A. cerana cell size was modified and the queens were reluctant to lay eggs on such combs. In pure A. cerana colonies, the A. mellifera cell size was built without any modification but these cells were used either for drone brood rearing or for food storing. The principal elements of comb-building behaviour are common to both species, which indicates that they evolved prior to and were conserved after speciation.

Responses of queenright and queenless workers of Apis cerana to 9-keto-2(E)-decenoic acid, a pheromonal constituent of the mandibular gland.

In dequeened honeybee colonies ovarian activation occurs in some workers, and the pheromonal bouquets of these laying workers become more queen-like. In the Asiatic honeybee, Apis cerana, we compared the amount of 9-keto-2(E)-decenoic acid (9-ODA), a mandibular gland pheromone component, between non-laying workers from queenright colonies and laying workers from queenless colonies, and further, applied synthetic 9-ODA to workers to determine whether they discriminate workers with activated ovaries based on the level of this compound. Levels of 9-ODA were higher in laying workers from dequeened colonies than in non-laying workers from queenright colonies. In both queenright and queenless colonies, workers attacked more workers treated with 9-ODA than control-treated workers. These results suggest that detection of pseudoqueens in A. cerana is mediated by changes in 9-ODA.

Interspecific utilisation of wax in comb building by honeybees.

Beeswaxes of honeybee species share some homologous neutral lipids; but species-specific differences remain. We analysed behavioural variation for wax choice in honeybees, calculated the Euclidean distances for different beeswaxes and assessed the relationship of Euclidean distances to wax choice. We tested the beeswaxes of Apis mellifera capensis, Apis florea, Apis cerana and Apis dorsata and the plant and mineral waxes Japan, candelilla, bayberry and ozokerite as sheets placed in colonies of A. m. capensis, A. florea and A. cerana. A. m. capensis accepted the four beeswaxes but removed Japan and bayberry wax and ignored candelilla and ozokerite. A. cerana colonies accepted the wax of A. cerana, A. florea and A. dorsata but rejected or ignored that of A. m. capensis, the plant and mineral waxes. A. florea colonies accepted A. cerana, A. dorsata and A. florea wax but rejected that of A. m. capensis. The Euclidean distances for the beeswaxes are consistent with currently prevailing phylogenies for Apis. Despite post-speciation chemical differences in the beeswaxes, they remain largely acceptable interspecifically while the plant and mineral waxes are not chemically close enough to beeswax for their acceptance.

Computerized neuropsychological profiles of South African versus US athletes: a basis for commentary on cross-cultural norming issues in the sports concussion arena.

Computerized programs are widely used as part of the overall medical management of concussion in order to monitor recovery and facilitate safe return-to-play decisions. Typically, neurocognitive profiles of concussed athletes are compared with baseline and/or normative data in the absence of baseline scores. However, the cultural equivalence of performance on neuropsychological tests cannot be assumed and has not been sufficiently researched. The purpose of this study was to investigate the neuropsychological test profiles of the ImPACT (Immediate Postconcussion Assessment and Cognitive Testing) on age-matched South African (SA) rugby and US football players. Participants included 11 257 English-speaking, predominantly white male athletes from multiple SA and US schools and sports organizations in 3 age groups: 11 to 13 years (SA, n = 301; US, n = 775); 14 to 16 years (SA, n = 997; US, n = 4081); and 17 to 21 years (SA, n = 319; US, n = 4784). ImPACT neurocognitive composite scores (verbal and visual memory, visual motor speed, reaction time, impulse control) and the ImPACT total symptom score, derived from the initial baseline testing, were used for comparison purposes between the targeted groups. Independent t-test comparisons revealed overall equivalence between the SA and US athletes on the neurocognitive measures, but they also revealed consistently higher symptom scores for SA athletes in association with clinically relevant effect sizes. It was concluded that US neurocognitive normative data on the ImPACT test are appropriate for use on South African athletes whose first language is English, whereas culture-specific sensitivity for symptom reporting on this same population should be taken into consideration for management purposes. It is argued that neurocognitive equivalence is less likely to apply in educationally disadvantaged populations. The use of registered psychologists is deemed necessary to provide contextualized interpretations of computerized test scores, thereby protecting against misdiagnosis that may occur within the concussion management arena via actuarial approaches that fail to take sociocultural complexities into account.

The comparative incidence of reported concussions presenting for follow-up management in South African Rugby Union.

OBJECTIVE: The objective of this study was to compare the seasonal concussion incidence for school, university, club and provincial level Rugby Union players in South Africa. DESIGN: The study presents a retrospective statistical analysis of the number of reported concussions documented annually for groups of Rugby Union players as a proportion of those who received preseason neurocognitive assessment. SETTING: Between 2002 and 2006, concussion management programs using computerized neuropsychological assessment were implemented for clinical and research purposes by psychologists in selected South African institutions involved in Rugby Union from school through to the professional level. PARTICIPANTS: The incidence figures were based on 175 concussive episodes reported for 165 athletes who were referred for neurocognitive assessment from a population of 1366 athletes who received preseason baseline testing. INTERVENTIONS: Concussion management routines varied according to the protocols adopted by the different psychologists and rugby organizations. MAIN OUTCOME MEASUREMENTS: It was expected that the incidence of concussion would vary significantly due to level of play and different management protocols. RESULT: There was wide disparity in the manner in which concussion follow-up was managed by the various organizations. Within broadly comparable cohorts, tighter control was associated with a relatively higher concussion incidence for athletes per rugby playing season, with average institutional figures ranging from 4% to 14% at school level and 3% to 23% at adult level. CONCLUSIONS: This analysis suggests that concussion goes unrecognized and therefore incorrectly managed in a number of instances. Recommendations for optimal identification of concussed athletes for follow-up management are presented.

Nectar secretion dynamics of Ziziphus nummularia: A melliferous species of dry land ecosystems.

Nectar is used as raw material for the production of honey and as significant reward in the relationship between bees and plants during pollination. Therefore, it is important to investigate its abundance, dynamics and associated governing factors. Weather conditions are known to influence nectar production, and predicted climate changes may be responsible for future declining in total yield from beekeeping activities. We investigated nectar production as total soluble solids (TSS) of well-known species for honey production, Ziziphus nummularia in a hot-arid environment of Saudi Arabia. Data on nectar samples from bagged flowers of different stages during two blooming seasons, 2013 and 2015 were collected on weekly bases, and the data were correlated with weather conditions (temperature, relative humidity, and wind). A significant difference in TSS amount has been obtained, with 1-day old flowers displaying the higher content. TSS production was varied along the different day intervals, for both years, with a peak of production in the afternoon. In our results, nectar production was not correlated to temperature and wind, but was significantly negatively correlated with relative humidity. According to the current and future weather forecasting conditions, understanding of the relationship between weather conditions and nectar availability turned out to be important predictive information that may be interpreted into an economic projection of incomes from beekeeping activities.

Vulnerability in speed of visuomotor ability.

The aim of this report is to illustrate the utility of neurocognitive testing as an investigative method to establish the presence of persistent effects of concussive brain injury amongst players of a contact sport with high risk of such injury. The report reviews the outcomes of three previously published neuropsychological studies on South African Rugby Union (hereafter 'rugby') from school through to the national adult level. The diagnostic utility of differential effects per se, as well as differential practice effects on visuomotor function, as a means of distinguishing poorer neurocognitive outcome for rugby versus demographically equivalent noncontact sports players, is described. From various methodological angles, at each level of play, the reviewed studies attest to the presence of long-term vulnerability in visuomotor speed in association with participation in rugby, in turn implicating diffuse frontotemporal dysfunction due to repetitive concussive and subconcussive injury amongst rugby players. As visuomotor speed is a prime function called upon for optimal scholastic and occupational performance, the robustly demonstrated decrement is of immediate clinical importance. Of critical heuristic relevance, however, is evidence of residual brain dysfunction in association with rugby as early as school level, which may ultimately be the precursor of chronic traumatic encephalopathy.

Practice effects reveal visuomotor vulnerability in school and university rugby players.

This article reports on three pre- versus post-season prospective studies in which male university and high school contact sport players predominantly of Rugby Union (hereafter rugby) were compared with age, education, and IQ equivalent non-contact sport controls on the ImPACT (Immediate Postconcussion Assessment and Cognitive Testing) test. All analyses revealed a relative absence of practice effects on the Visual Motor Speed (VMS) composite for contact sport groups compared with controls. The VMS data for rugby players from each study were pooled and subjected to additional analysis (Rugby, n = 145; Controls, n = 106). Controls revealed significant improvement over the season (p < .001), whereas no learning effect was in evidence for rugby players whose performance remained the same (interaction effect, p = .028). It is apparent that practice effects have diagnostic potential in this context, implicating vulnerability on speeded visuomotor processing in association with participation in rugby. Pointers for further research and concussion management in the individual case are explored.

Lime pretreatment of sugar beet pulp and evaluation of synergy between ArfA, ManA and XynA from Clostridium cellulovorans on the pretreated substrate.

Sugar beet pulp (SBP) is a waste product from the sugar beet industry and could be used as a potential biomass feedstock for second generation biofuel technology. Pretreatment of SBP with 'slake lime' (calcium hydroxide) was investigated using a 2(3) factorial design and the factors examined included lime loading, temperature and time. The pretreatment was evaluated for its ability to enhance enzymatic degradation using a combination of three hemicellulases, namely ArfA (an arabinofuranosidase), ManA (an endo-mannanase) and XynA (an endo-xylanase) from C. cellulovorans to determine the conditions under which optimal activity was facilitated. Optimal pretreatment conditions were found to be 0.4 g lime/g SBP, with 36 h digestion at 40 °C. The synergistic interactions between ArfA, ManA and XynA from C. cellulovorans were subsequently investigated on the pretreated SBP. The highest degree of synergy was observed at a protein ratio of 75% ArfA to 25% ManA, with a specific activity of 2.9 U/g protein. However, the highest activity was observed at 4.2 U/g protein at 100% ArfA. This study demonstrated that lime treatment enhanced enzymatic hydrolysis of SBP. The ArfA was the most effective hemicellulase for release of sugars from pretreated SBP, but the synergy with the ManA indicated that low levels of mannan in SBP were probably masking the access of the ArfA to its substrate. XynA displayed no synergy with the other two hemicellulases, indicating that the xylan in the SBP was not hampering the access of ArfA or ManA to their substrates and was not closely associated with the mannan and arabinan in the SBP.

Economics of comb wax salvage by the red dwarf honeybee, Apis florea.

Colonies of Apis florea, which only abscond a short distance, usually return to salvage old nest wax; but, those colonies, and all other honeybee species which go considerably further, do not. Wax salvage would clearly be counter-productive unless the energy input/energy yield threshold was a profitable one. There are two possible trade-offs in this scenario, the trade-off between the energy expended to recover the wax (recovering hypothesis) as against that of replacing the wax by new secretion (replacing hypothesis). In order to compare the two hypotheses, the fuel costs involved in salvaging wax on one return trip, the average flower handling time, flight time and relative values for substituting the salvaged wax with nectar were calculated. Moreover, the energy value of the wax was determined. Net energy gains for salvaged wax were calculated. The energy value of the salvaged wax was 42.7 J/mg, thus too high to be the limiting factor since salvaging costs are only 642.76 mJ/mg (recovering hypothesis). The recovery costs (642.76 mJ/mg) only fall below the replacement costs for absconding distance below 115 m thus supporting the replacing hypothesis. This energetic trade-off between replacing and recycling plus the small absconding range of A. florea might explain why A. florea is probably the only honeybee species known to salvage wax and it parsimoniously explains the underlying reasons why A. florea only salvages wax from the old nest if the new nesting site is less than 100-200 m away-energetically, it pays off to recycle.

Thermoregulation in mixed-species colonies of honeybees (Apis cerana and Apis mellifera).

Apis cerana and Apis mellifera normally display different strategies in cooling hive temperature, raising the question whether they would coordinate their efforts in to achieve stable thermoregulation in mixed colonies. The results show that the normal temperatures in the brood area in mixed colonies are more similar to those of pure A. cerana colonies than pure A. mellifera colonies. Under heat stress, A. cerana workers are more sensitive, and initiate fanning earlier than A. mellifera workers. In mixed colonies, the former become the main force for thermoregulation. When worker bees of both species were fanning together at the entrance, their own species-specific postures were adopted, but due to a significantly smaller number of A. mellifera workers engaged in fanning, the cooling efficiency of mixed colonies were closest to that of pure A. cerana colonies.

Sun angle time windows for absconding by the dwarf honeybee, Apis florea.

In Asia, the red dwarf honeybee, Apis florea, is notorious for its absconding habit. Interestingly, such colonies show a bimodal frequency distribution about a noonday lull throughout the year. Because slight errors in reading the relative position of the sun near its zenith results in very large orientation errors in the waggle dances of other honeybees in the tropics, we postulated that the frequency distribution of absconding in the red dwarf honeybee relative to local clock time could be explained in similar fashion. The frequency distribution of absconding by the red dwarf honeybee with respect to time was found to be bimodal with a pronounced lull at noonday, which in turn is related to the altitude angle of the sun. So, these bees largely avoid flying off between 12:00h and 13:00h on the one hand and that their preferred departure angle of the sun is between 55 degrees and 65 degrees on the other. Given the difficulties of taking an accurate reading of the sun at angles +/-6 degrees of the sun's zenith (resulting in a 1h loss around noon) and the 2h required to reach consensus over the final direction to be flown, the bees are simply left with two time windows, morning and afternoon, in which to abscond and, indeed some 90% of the red dwarf honeybee colonies do so. The noonday lull is not associated with high temperatures for any given day. Absconding is not inhibited by high temperatures.

Compromised visuomotor processing speed in players of Rugby Union from school through to the national adult level.

The aim of this study was to investigate the residual effects of concussion amongst players of Rugby Union from school through to the national adult level, with pre-season testing on tests of visuomotor processing speed (Digit Symbol; Trail Making Test A and B). Comparison groups included 124 male rugby players versus 102 non-contact sport controls; 71 forward versus 53 backline players. Across groups there was equivalence for age, education, estimated IQ, and hand motor dexterity. There was a significantly higher percentage of rugby players with 2+ concussions than controls. Poorer performance was in evidence for rugby players compared with controls on all tests of visuomotor speed, and for forward versus backline players on Digit Symbol, with clinically relevant medium effect sizes. The results implicate vulnerability amongst rugby players on the prototypically sensitive function of visuomotor processing in association with years of exposure to repetitive concussive and subconcussive injury.

Neurocognitive vulnerability amongst university rugby players versus noncontact sport controls.

University rugby players were compared with IQ-equivalent noncontact sports controls on memory and attentional tasks at the pre- and postseason intervals. Results revealed significant lowering for rugby players relative to controls at the postseason interval for attentional tasks with a speeded visuomotor component (ImPACT Visual Motor Speed; Trail Making Test, TMT, A and B). There was a practice effect for controls only between the pre- and postseason intervals for attentional tasks that commonly reveal improvements after a long retest interval (TMT A and B; Digits Backwards). Medium to large effect sizes implicate clinically relevant cognitive vulnerability for university-level rugby players in association with years of exposure to repetitive concussive injury.

Self assessment in insects: honeybee queens know their own strength.

Contests mediate access to reproductive opportunities in almost all species of animals. An important aspect of the evolution of contests is the reduction of the costs incurred during intra-specific encounters to a minimum. However, escalated fights are commonly lethal in some species like the honeybee, Apis mellifera. By experimentally reducing honeybee queens' fighting abilities, we demonstrate that they refrain from engaging in lethal contests that typically characterize their reproductive dominance behavior and coexist peacefully within a colony. This suggests that weak queens exploit an alternative reproductive strategy and provides an explanation for rare occurrences of queen cohabitation in nature. Our results further indicate that self-assessment, but not mutual assessment of fighting ability occurs prior to and during the agonistic encounters.

The role of insight into and beliefs about medicines of hypertensive patients.

OBJECTIVES: One aim of this study was to determine the level of knowledge and understanding of selected individuals about hypertension, as well as their beliefs and perceptions about medicines. The other purpose was to determine the medicines information provision system that these participants were exposed to. METHODS: Participants filled in the Beliefs about Medicines questionnaire and one-on-one interviews were conducted. Participants gave informed consent and their health passports were examined. A focus-group discussion was held with some of the nurses at one of the local clinics. RESULTS: Participants believed their antihypertensive therapy was necessary for them to maintain their health. However, there was also a high level of concern about the undesirable effects of the medication. Most participants did not understand what hypertension is, however, they were aware of the consequences of uncontrolled blood pressure. There was no structured patient education system at the public clinic investigated. CONCLUSION: A knowledge gap existed which needed to be filled. Participants' concerns about the undesirable effects of antihypertensive therapy needed to be addressed. A structured medicines information provision system is required at the public clinic studied, to ensure that patients receive all the pertinent information about their condition, namely hypertension, and the prescribed therapy.

Rare royal families in honeybees, Apis mellifera.

The queen is the dominant female in the honeybee colony, Apis mellifera, and controls reproduction. Queen larvae are selected by the workers and are fed a special diet (royal jelly), which determines caste. Because queens mate with many males a large number of subfamilies coexist in the colony. As a consequence, there is a considerable potential for conflict among the subfamilies over queen rearing. Here we show that honeybee queens are not reared at random but are preferentially reared from rare "royal" subfamilies, which have extremely low frequencies in the colony's worker force but a high frequency in the queens reared.