Host plant and crowding effects in the induction of alatae in the large pine aphid, Cinara pinea

Alate virginoparae of Cinara pinea occur on Scots pine trees only during June and early July, when population numbers are at their highest. Crowding experience during nymphal life promotes the development of winged adults, but only if the tree is in the stage of active shoot growth. Later in the season when shoots are mature, alatae are suppressed, irrespective of crowding. Changing daylength and temperature do not appear to influence alate production and maternal experience of crowding has no effect on the nymphal response. The possible nature of the host plant effect is discussed in the light of this and previous work.

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Résumé Les virginipares ailés de Cinara pinea apparais sent sur Pinus sylvestris L. uniquement en juin et au début juillet, quand les effectifs de la population sont au plus haut. Des expériences de surpeuplement pendant le dernier stade larvaire n'induisent le développement d'adultes ailés que si l'arbre est au stade où la croissance des pousses est active. Plus tard dans la saison, quand les pousses sont mûres, les ailés sont réprimés, quel que soit le surpeuplement. Les modifications de la longueur du jour et de la température ne semblent pas influencer la production d'ailés et le surpeuplement subi par les mères n'a pas d'effet sur la réponse des larves âgées. La nature de cet effet de la plante-hôte est envisagée à la lumière de cette étude et de travaux précédents.

     

Clinical applications of cytometry: 5th annual meeting

The 5th annual Clinical Applications of Cytometry meeting was held September 12-15, 1990 in charleston, SC. The theme which emerged repeatedly throughout the meeting was the need to take full advantage of the quantitative power of cytometry to provide the most useful clinically relevant diagnostic and prognostic information. Greater quantitative power is based on careful and reproducible standards and quality control. The same principles, albeit with somewhat different approaches, apply to cell surface immunofluorescence analysis, DNA measurements, and image cytometry assessments. Monoclonal antibody probes against oncogenes, others against lymphokines within the Golgi, and a novel fluorogenic substrate designed to quantitate the activity of a mitochondrial enzyme were exciting developments described at the meeting.     

Small-scale production of the common green lacewing Chrysoperla carnea (Stephens) (Neuropt., Chrysopidae): minimizing costs and maximizing output

This paper outlines a system for the production of common green lacewings in the laboratory, using easily available and inexpensive equipment and producing a healthy surplus of insects for experimental purposes. An economic breakdown of costs is given.     

Little Foot and big thoughts—a re-evaluation of the Stw573 foot from Sterkfontein, South Africa

The part of the fossil assemblage Stw573 consisting of some medial foot bones was initially reported by Clarke & Tobias (Science 269 (2002) 521). They found it to have both ape- and human-like qualities, being human-like proximally and ape-like distally. We have undertaken a re-examination of this pedal assemblage using a multivariate analysis; while we also found ape- and human-like qualities, they are in direct conflict with the original findings of Clarke and Tobias. We report an essentially ape-like morphology proximally and a human-like morphology distally; the talus and navicular were found to be ape-like and the medial cuneiform human-like. We also undertook a morphometric analysis of the medial cuneiform from the fossil assemblage OH8, as this was not included in the original OH8 study of Kidd et al (J Hum Evol 31 (1996) 269); this cuneiform was found to have a human-like morphology. Thus, the medial column findings from the two assemblages are very similar. This finding, coupled with the re-evaluation of the stratigraphy at Sterkfontein (Am J Phys Anthrop 119 (2002) 192), suggests that the two may have been contemporaneous.

We also note that three broad patterns of modification have been identified, equating to proximal–distal lateral–medial (cranio–caudal) and dorsal–plantar (posterior–anterior). It has not escaped our notice that these patterns are each controlled by specific genes or growth factors; we thus see a morphometric expression of our developmental past.     

Toward a Typology of Dynamic and Hazardous Work Environments

The most hazardous work environments share one feature in common: constant change. Many different, but constantly changing hazards are found in agriculture, construction, mining, and transport. This dynamic feature of workplace hazards varies by: (1) degree of control, (2) predictability, (3) visibility, (4) movement, and (5) degree of speed and force. In some cases the actions of the dynamic hazards are required for production to take place, and in many cases, several different hazards may overlap and interact. Finally, whether intentional or unintentional, some dynamic hazards are human generated. These are some of the features that distinguish dynamic and hazardous work environments across a variety of industries. The authors propose a preliminary typology of dynamic and hazardous work environments, along with a schema to systematically observe the dynamic characteristics of these hazards. The implications of this typology are considered with respect to worker training, hazard awareness, and safe work practices. For example, the implementation of the Hierarchy of Control is shown to require active worker involvement at every level in the hierarchy, except where an environmental hazard has been completely eliminated.     

Histochemical staining of protein-tyrosine phosphatase activity in primary human mammary carcinoma: relationship with established prognostic indicators.

Protein-tyrosine phosphatase (PTPase) activity in frozen human mammary primary carcinoma tissue sections has been quantitated using a modified histochemical assay. The improved method features the assay of PTPase activity in 12-microns sections of air-dried unfixed tissues, and the use of [2-(N-morpholino)-ethanesulfonic acid] (MES) buffer to prepare stable reaction solutions. Tissue samples from 53 primary human mammary carcinomas were assayed for PTPase activity, and immunohistochemically stained for c-erbB-2 protein-tyrosine kinase expression. Elevated levels of PTPase activity were found in 68% of the tumors compared with the level of activity found in normal human mammary tissues. PTPase activity was co-localized with pathology definitive for carcinoma. Excessive activity was demonstrated throughout the cell, with high activity evident in the cell cytoplasmic membrane and the nucleus. Coexistence of elevated expression of c-erbB-2 and increased PTPase activity was present in 53% of the tumors. In contrast, 15% displayed low c-erbB-2 expression and high PTPase activity, and 24% displayed high c-erbB-2 expression and low PTPase activity. No statistically significant association was found between increased PTPase activity and either c-erbB-2 overexpression or grade and stage of disease in primary human mammary tumors.