Physiology of Sex in Cucumis Sativus (L.) Leaf Age Patterns and Sexual Differentiation of Floral Buds

One of the factors which control the sexual differentiationof the floral primordium in the cucumber plant may be the hormonalbalance in its vicinity; a balance in favour of growth substance,like IAA, may enhance the female tendency while low concentrationsof these substances or higher concentration of their antagonistsmay cause an increase in the proportion of male flowers. In the present work it is shown that whenever the female tendencyis strong, the floral buds develop next to younger leaves; thereverse is true for plants of a stronger male tendency. Thisrule was found to hold true where environmental conditions—like length of day and night-temperature—affected thesex tendency, as well as in the case of the main branch of thecucumber plant, where an increasing female tendency is found.No difference in leaf age-flowerbud relations was detected whendifferent levels of nitrogen were fed to the plants, and thedifferent N leveb had no effect on the sex tendency of the plants. It is pointed out that a similar situation was found in earlierwork where the difference in sex tendency was due to geneticfactors. It is suggested, therefore, that both environmentaland genetic factors, which are known to affect sex tendencyin the cucumber plant, work through changing the leafage-flowerbudrelationship. Presumably this is related to the hormonal balancein the vicinity of the developing floral primordium.     

MORPHOGENESIS IN SPIEODELA OLIGORRHIZA: EFFECTS OF PYRIMIDINE BASE ANALOGUES ON INITIATION, ELONGATION AND DIFFERENTIATION OF FRONDS

The effect of four pyrimidine base analogues and their antidoteson S. oligorrhiza was studied. FUdR stopped cell division at concentrations of 4 10^–7M and higher. This effect could be nullified by the additionof 4 10^–6 M thymidine. Neither uridine nor uracil hadan antidotal effect on FUdR. FU (8 10^–6 M or higher concentration) affected celldivision, frond elongation and differentiation, and could notbe counteracted by either thymidine or uracil. TU (8 10^–4 M) rather specifically inhibited differentiationof frond tissues, while not preventing cell division or theinitiation of new generations. Uracil and uridine at about equimolarconcentrations completely counteracted the TU effect. AzU (10^–3 M) suppressed cell division, frond elongationand frond differentiation. When thymidine (10^–3 M) wasadded simultaneously with AzU only cell elongation and differentiationof fronds were inhibited, but cell division proceeded. 10^–3M uracil (but not uridine) counteracted all effects of AzU. ¹ Based on a portion of the senior author's Ph.D. Thesis.     

NEXT GENERATION HEALTHY SOUP: AN EXPLORATION USING CONJOINT ANALYSIS

This paper presents results on consumer attitudes towards healthy soup, using conjoint analysis, executed on the Internet. The results show moderate interest in new ideas for the total panel, but reveal three concept-response segments. The first segment responds to nutrition and functional ingredients. The second segment responds to packaging and convenience. The third segment responds to taste and ingredients. Statistical analysis confirms the idea that they represent different 'mind-sets'. The segmentation based on psychographic variables is a useful tool to identify the features of the next generation "healthy soups" and to design custom products on the basis of consumer requirements.     

Gorging response of Glossina palpalis palpalis to ATP analogues

ABSTRACT. The potencies of seventeen analogues of ATP as gorging inducers for Glossina palpalis palpalis were evaluated. The ranking for effective dose that induced half the flies to gorge (ED₅₀) was: A tetra P 5 ATP=2'd ATP ADP=2'd ADP > AMP-PNP > 3'd ATP 2'3'dd ATP > AMP-PCP > adenosine 5' triphosphate 2',3'dialdehyde AMP-CPP >> AMP. Females detect ATP and its analogues better than males. The ED₅₀ of ATP was 5 × 10^-7 M for teneral females and 1.5 × 10^-6 M for males. According to the potency order of the ATP analogues, the G.p.palpalis gustatory receptors recognizing ATP can be classified as P_2y purinoceptors.     

A CARBONIFEROUS SYNZIPHOSURINE (XIPHOSURA) FROM THE BEAR GULCH LIMESTONE, MONTANA, USA

Abstract:  A new synziphosurine, Anderella parva gen. et sp. nov., extends the known range of this group from the Silurian to the Carboniferous and is the youngest known so far from the fossil record. Previously the youngest synziphosurine, Kasibelinurus , was from the Devonian of North America. Anderella parva has a semi-oval carapace with pointed genal regions, nine freely articulating opisthosomal segments and a long styliform tail spine. It is the third xiphosuran genus to be described from the Bear Gulch Limestone and its discovery highlights this deposit as containing an unusually diverse xiphosuran biota. It is also the only known locality where synziphosurines occur alongside the more derived xiphosurids. Xiphosurans reached their greatest diversity in the Carboniferous when the xiphosurids began to occupy brackish and freshwater habitats and became dominant over the synziphosurines. The discovery of the only known Carboniferous synziphosurine in marine sediments may indicate their inability to exploit these same environments.     

The ecology and phylogeny of oomycete infections in Asplanchna rotifers

1. Recently, the potential for parasites to influence the ecology and evolution of their zooplankton hosts has been the subject of increasing study. However, most research to date has focussed on Daphnia hosts, and the potential for parasites to influence other zooplankton taxa remains largely unstudied. 2. During routine sampling of zooplankton in a eutrophic lake, we observed that the rotifer Asplanchna girodi was often infected with a parasitic oomycete. Epidemics of this parasite occurred frequently, with three separate events in a single year. Prevalence at peak infection ranged from 29 to 41% and epidemics lasted from 17 to 56 days. Our data indicate that high densities of the host population are required for epidemics to occur. 3. Our morphological and molecular analyses suggest that this parasite is in the genus Pythium. Most Pythium spp. are plant pathogens, but our study supports recent work on Daphnia, suggesting that Pythium spp. are also important parasites of zooplankton. 4. As the parasite in this study was recalcitrant to cultivation, we developed an alternative method to verify its identity. Our approach used quantitative PCR to show that the ribosomal sequences identified increased with increasing density of infected hosts and, thus, were associated with the parasite. This approach should be generally applicable to other plankton parasites that are difficult to cultivate outside their hosts. 5. Infections significantly reduced host fecundity, lifespan and population growth rate. As a result of the virulence of this parasite, it is likely to influence the population ecology and evolution of its Asplanchna host, and may be a useful model system for studies on host–parasite coevolutionary dynamics.     

HISPANIC AND NON-HISPANIC RESPONSES TO CONCEPTS FOR FOUR FOODS

Hispanics and non‐Hispanics Americans participated in four sets of studies dealing with health‐oriented foods, with the goal to identify how they respond to food categories relevant in any cuisine. Each study comprised a conjoint analysis using 36 elements followed by a self‐profiling questionnaire to learn more about Hispanic and non‐Hispanic food responses to concepts for four different product categories (morning bread, bottled water, healthful salad dressing and popcorn as a snack). The study identified patterns of preference of marketing statements in the areas of health information, sensory characteristics, emotional benefits and endorsements. Conjoint utility values generated by both Hispanics and non‐Hispanic respondents correlated highly, suggesting that their food attitudes are quite similar for“non‐signature”products despite the differences in their original cuisines.     

Integration of mental health into primary care in Kenya

Integration of mental health into primary care is essential in Kenya, where there are only 75 psychiatrists for 38 million population, of whom 21 are in the universities and 28 in private practice. A partnership between the Ministry of Health, the Kenya Psychiatric Association and the World Health Organization (WHO) Collaborating Centre, Institute of Psychiatry, Kings College London was funded by Nuffield Foundation to train 3,000 of the 5,000 primary health care staff in the public health system across Kenya, using a sustainable general health system approach. The content of training was closely aligned to the generic tasks of the health workers. The training delivery was integrated into the normal national training delivery system, and accompanied by capacity building courses for district and provincial level staff to encourage the inclusion of mental health in the district and provincial annual operational plans, and to promote the coordination and supervision of mental health services in primary care by district psychiatric nurses and district public health nurses. The project trained 41 trainers, who have so far trained 1671 primary care staff, achieving a mean change in knowledge score of 42% to 77%. Qualitative observations of subsequent clinical practice have demonstrated improvements in assessment, diagnosis, management, record keeping, medicine supply, intersectoral liaison and public education. Around 200 supervisors (psychiatrists, psychiatric nurses and district public health nurses) have also been trained. The project experience may be useful for other countries also wishing to conduct similar sustainable training and supervision programmes.