Maternal protectiveness and response to the unfamiliar in vervet monkeys

Vervet monkeys (Cercopithecus aethiops sabaeus) show individual differences in approach-avoidance behavior when faced with an unfamiliar and potentially threatening situation. Prior research from our colony demonstrated that juveniles who had experienced high levels of early maternal protectiveness were more cautious in response to novelty, compared to juveniles who had had less protective mothers. The research reported here was designed to verify this result in a paradigm that experimentally varied maternal protectiveness through the introduction of new breeding adult males. Mothers responded to the presence of new males by increased maternal protectiveness toward infants born in the year following the introductions. Individual differences in response to the unfamiliar were later evaluated by measuring the latency to approach within 1 m of novel food containers placed into the home enclosure of four naturally composed social groups. Infants approached with the same latency and in the same order as their mothers. Juveniles approached sooner than, and independent of, their mother's current behavior, but their latency to approach could be predicted by the experimentally induced variation in maternal protectiveness they had experienced as infants. Immatures who had been born in New Male years, when maternal protectiveness was high, were more cautious and had significantly longer latencies to approach the novel stimulus compared to immatures who had been born in Resident Male years. © 1993 Wiley-Liss, Inc.     

The ecological significance of toxic nectar

Although plant-herbivore and plant-pollinator interactions have traditionally been studied separately, many traits are simultaneously under selection by both herbivores and pollinators. For example, secondary compounds commonly associated with herbivore defense have been found in the nectar of many plant species, and many plants produce nectar that is toxic or repellent to some floral visitors. Although secondary compounds in nectar and toxic nectar are geographically and phylogenetically widespread, their ecological significance is poorly understood. Several hypotheses have been proposed for the possible functions of toxic nectar, including encouraging specialist pollinators, deterring nectar robbers, preventing microbial degradation of nectar, and altering pollinator behavior. All of these hypotheses rest on the assumption that the benefits of toxic nectar must outweigh possible costs; however, to date no study has demonstrated that toxic nectar provides fitness benefits for any plant. Therefore, in addition to these adaptive hypotheses, we should also consider the hypothesis that toxic nectar provides no benefits or is tolerably detrimental to plants, and occurs due to previous selection pressures or pleiotropic constraints. For example, secondary compounds may be transported into nectar as a consequence of their presence in phloem, rather than due to direct selection for toxic nectar. Experimental approaches are necessary to understand the role of toxic nectar in plant-animal interactions.     

Studies on an antineoplastic fraction from human urine. Characterization of the major protein in this fraction.

A fraction has been isolated from human urine which exhibits antiproliferative activity against human tumour cell lines without affecting the growth of several normal diploid cell lines or tumour cells of mouse or hamster origin. The major protein present in this fraction has been characterized and tentatively designated antineoplastic urinary protein (ANUP). An S020,W value of 3.69 S was obtained by sedimentation velocity analysis, and a subunit molecular mass of 16 300 Da was obtained by sedimentation equilibrium and by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Centrifugation data also indicated that the protein self-associates. The amino acid analysis of ANUP was consistent with its low pI (4.2) as determined by chromatofocusing analysis. Furthermore, the amino acid composition exhibited some features similar to collagen, as shown by high levels of proline and glycine, the absence of cysteine, and the presence of low levels of hydroxyproline.     

Royal College of Physicians and Surgeons of Canada: annual meeting draws over 2000 physicians

In a review of 19 years'' experience with inhalation of foreign bodies by children the 33 patients (mean age 28 months) were found to have presented most frequently with wheezing or coughing, or both, of recent onset, and to have decreased air entry, rhonchi or respiratory stridor, or a combination of these signs. Eighteen children had inhaled a nut, a pea or a bean. The other 15 had inhaled various organic and inorganic objects. All the children underwent bronchoscopy, and the foreign body was completely removed in 19 during the first procedure; the remainder required repeated bronchoscopy or direct surgical removal of the foreign body, or both. Permanent disability or death was not encountered. The findingsof the study indicate that early bronchoscopic removal is the preferred treatment when a child inhales a foreign body.     

Metabolic thermotolerance: magnetic resonance detected protection of glutamate synthase.

Metabolism in maize meristem cultures exposed to different heat treatments has been analyzed by 13C-NMR spectroscopy of tissue extracts. The effects of a 40 degrees C permissive stress were compared with a 45 degrees C lethal stress, and the metabolism of glutamate and glutamine were markedly altered by both temperatures. Changes in the incorporation of labeled precursors, alterations due to the in vivo application of enzyme inhibitors, and differences in the activity of enzymes in cell free extracts have confirmed that glutamate synthase (GluS) is partially inactivated by the lethal thermal exposure. This enzyme is quantitatively protected by the induction of thermotolerance. The time dependence for the protection correlates with the appearance of a set of late-arising heat shock proteins (hsps). The function of these late-arising proteins is not yet known, but only one of them, a 67-kDa protein, is spatially correlated with GluS protection. Therefore, the quantitative protection of a key metabolic enzyme has been correlated with the in vivo function of a specific hsp.