Cold shock and heat shock: a comparison of the protection generated by brief pretreatment at less severe temperatures

Abstract Brief exposure to low (0^oC) or high (40^oC) temperature elicits a protective response that prevents injury when the flesh fly, Sarcophaga crassipalpis Macquart, is subjected to more severe cold (-10^oC) or heat (45^oC). Both the low and high temperature responses were found in all developmental stages of the fly, but were most pronounced in the pupal and pharate adult stages. The protective responses generated by brief exposure to 0 or 40^oC appear similar in that both result in a rapid acquisition of cold or heat tolerance and a loss of protection after the flies are returned to 25^oC. The protection generated by chilling is obvious within 10 min of exposure to 0^oC while a 30 min exposure to 40^oC is required to induce the high temperature protection. High temperature protects against cold shock injury within a narrow range (around 36^oC) but we have no evidence that low temperature can protect against heat injury. We previously demonstrated that the rapid increase in cold tolerance correlates with concomitant increases in glycerol concentration, but in this study we found no significant elevation in glycerol in heat-shocked flies. Thus the physiological and biochemical bases for the rapid responses to cold and heat appear to be different.     

Behavioral Aspects of Rodent Population Biology

Five approaches to the study of behavior as a factor in thepopulation biology of rodents are outlined. These approachesare: (1) genetics, (2) physiology, (3) chronobiology,(4) behavioralecology and sociobiology, and (5) the use of intra- and inter-specificcomparisons. For each approach selected examples from the recentliterature, from this symposium and from my own work are usedto illustrate the new directions that are emerging for analyzingbehavior as a factor affecting natality, mortality and emigration/immigrationin rodents. Areas where additional investigations are neededare noted including some questions to be tested by future experiments.A variety of new techniques that have been developed or areinnovative applications of existing techniques are incorporatedinto the examples. Most of the material presented concerns fourgenera of rodents, Microtus, Mus, Peromyscus, and Rattus. Thefollowing major conclusions emerge from an overview of theseapproaches: Most recent research on behavior as a factor inrodent population biology has been concerned primarily withnatality. Few investigators have dealt with mortality and onlya limited number have explored emigration/immigration. Fieldand laboratory studies on behavioral aspects of rodent populationbiology have become more integrated than they were several decadesago. Both proximate and ultimate questions about behavior andpopulation dynamics are now being tested by both laboratoryand field methods. In contrast to some earlier approaches thatoften viewed population control as involving a single factor,most emerging conceptual frameworks have, as a major assumption,that population regulation is a multi-factorial process includingmany behavioral components.     

Abundance and biomass estimates of the benthic fauna in Admiralty Bay,King George Island,South Shetland Islands

Summary Quantitative benthic samples were collected along three transects in Admiralty Bay, King George Island, South Shetlands. At each of a total of 18 stations, between 15 and 250 m depth, we took 3 replicate samples with a van Veen grab. Animals collected were classed into major groups. Abundance and biomass per m² was calculated for each sampling site. Considerable population densities and high biomass values were found. Most abundant groups were Bivalvia, Polychaeta and Amphipoda, whereas the largest part of the biomass was due to Ascidiacea, Ophiuroidea, Echinoidea, Polychaeta and Bivalvia. The maximum abundance recorded was 36,000 ind m^-2 while the average was approximately 6500 ind m^-2. Maximum biomass was over 2400 g m^-2 with an average of ca. 700 g m^-2. The contribution to the total biomass by groups such as the Oligochaeta, Cumacea and Tanaidacea was higher in the inner shallow part of Admiralty Bay (Ezcurra Inlet) than in the deeper areas of the bay. Our results confirm the reports on an unusually high density and biomass of the Antarctic sublittoral benthic fauna. Sessile suspension feeders belonging to the Bivalvia, Ascidiacea, sedentary Polychaeta, and vagile scavengers of the Ophiuroidea, Amphipoda and errant Polychaeta are the most significant groups in the Antarctic Ecosystem. The total benthic biomass in Admiralty Bay, based on the present preliminary quantitative data, was estimated to be over 600,000 t. This value is probably still an underestimate.     

Some Microscopical Observations of Functioning Sieve Tubes of Heracleum using Nomarski Optics

The study of isolated phloem in Heracleum has been extendedto intact functioning sieve tubes. Techniques of phloem dissectioncombined with Nomarski interference optics have been developedto permit useful visual observations, photomicrography, andciné photographs of sieve tubes which are apparentlynormal. In these preparations, plastids and organelles calledby us ‘marker particles’ are visible in rapid bouncingmotion, and the state of dispersal of these particles is relatedto the amount of damage done to the preparations. The movement of the marker particles and their subsequent fixationshows that they are apparently attached to or restrained byan invisible network in situ. The network is very sensitiveto disturbance and readily collapses around the sieve platesto form slime plugs upon damage to the sieve element. The markerparticles do not move through the cell nor across sieve platesin mature Heracleum. In young cells cyclosis is observable alongthe periphery and this suggests that a vacuole may then be present.In undamaged mature cells there was evidence neither of a vacuolenor of trans-cellular tubules of any size optically detectable. The motion of the particles was greater than Brownian movementand appeared to be under some physiological control. Their movementprobably indicated the presence of an operating transport phenomenon,either because solution was moving past them in the sieve tubeor because they were themselves attached to a contractile networkactively in pulsatory motion. Nearby companion and parenchymacells showed normal cytoplasmic streaming. Proposed mechanisms of translocation involving cytoplasmic streamingdo not seem to be applicable to the phloem of Heracleum. Themovement of the marker particles seemed to agree best with amechanism of ‘activated’ mass flow.     

中国蝶类新种小志Ⅳ

本文记述国产眼蝶科(Satyridae)的一个新属Sinonympha与它的一个模式种Sinonympha amoena(新种),这一蝶类最早是笔者于1939年7月在我国四川省西北部的杂谷脑(理县)发见的。为欲较全面地了解它们在分类系统上的亲缘关系,又于1963年和1964年在原产地采集了大量的成虫标本,并于1965—1966年在北京饲养了它的幼期。 新华新眼蝶属Sinonympha新属 新属属征 新华新眼蝶属Sinonympha(新属)与Coenonympha Hbner(1819)较为近似,但是某些形态特征和生物学特性(包括幼期)则与Ypthima Hbner(1818),OeneisHbner(1819)以及Mycalesis Hbner(1818)等属的种类互有相似之处,现将本新属的主要特征列述于下:     

Colony development and formation in halysitid corals

Lee, D.-J. & Noble, J. P. A. 1990 04 15: Colony development and formation in halysitid corals. Lethaia , Vol. 23. pp. 179–193. Oslo. ISSN 0024–1164.
Modes of colony formation and their relationship with colony morphology, size and substrate characteristics in species of halysitid corals have been studied. Two distinctive modes of colony formation in halysitids are proposed. In the monoplanulate mode. represented by Catenipora snnplex . the colony is developed from a single protocorallite and colony formation is achieved by a combination of asexual increase and intracolony fusions. In contrast, the polyplanulatc mode is demonstrated by C. escharoides . in which the early colony formation is achieved primarily by fusions of many 'incipicnt colonies' of more than a single planulate origin and of different generations. The latter mode has not previously been described in tabulates and has significant implications for coloniality, reproductive and life history characteristics, histo-compatibility and adaptative ecology. The colony size and morphology. and The distribution of halysitid species were primarily determined by the modes of colony formation and the substrate characteristics. Colonies of the monoplanulate mode. when developed on soft substrates, exhibit a small and spherical morphology with isolated distribution patterns, while those developed on hard substrates are tabular and variable in size. depending on the availability of substrate. In colonies of the polyplanulate mode, on the other hand. the size of the colony is largely dependent on The frequency and timing of allograft fusion. They are characteristically found on soft substrates. often as dense mono specific thickets. The mode of colony formation in halysitids is probably species-specific and results in the adaptation to substrates. * Colony development, halysitid corals, Anticosti Island. Gotland .     

Homologies to the tomato endopolygalacturonase gene in the peach genome

Abstract. Peach endopolygalacturonase was isolated from the mesocarp tissue of soft ripe, freestone peach fruit, but was not detectable in mature pre-ripening fruit. It is a basic protein with a M_r of approximately 45000 Da, and cross-reacts with antibody to tomato endopolygalacturonase. Using a cDNA to the tomato enzyme as a probe, a fragment of peach genomic DNA was isolated which encoded about 50% of the peach enzyme. The nucleotide sequence of the fragment was determined and the amino acid sequence of part of the peach endopolygalacturonase peptide derived. Coding regions of the peach gene show extensive homology with related regions of the tomato gene. Introns are dissimilar. Endopolygalacturonase activity occurs in ripe 'freestone'peaches but not in the firmer 'clingstone'varieties. Hybridization studies identified a similar gene fragment in freestone, semi-freestone and clingstone peach varieties.     

Sensitive detection of mycoplasmalike organisms in field-collected and in vitro propagated plants of Brassica, Hydrangea and Chrysanthemum by polymerase chain reaction

A polymerase chain reaction (PCR) protocol, previously designed for amplification of a DNA fragment from aster yellows mycoplasmalike organism (MLO), was employed to investigate the detection of MLO DNA in field-collected and in vitro micropropagated plants. PCR with template DNA extracted from symptomatic, naturally-infected samples of Brassica, Chrysanthemum and Hydrangea, each yielded a DNA band corresponding to 1.0 Kbp. However, no DNA product was observed when either infected Ranunculus (with phyllody disease) or Gladiolus with (symptoms of ‘germs fins’) was used as source of template nucleic acid for PCR; further experiments indicated absence of target DNA in the case of Ranunculus and the presence of substances in Gladiolus which inhibited the PCR. The MLO-specific DNA was detected by PCR using less than 95 pg of total nucleic acid (equivalent to total nucleic acid from 1.9, ug tissue) in the case of field-collected Hydrangea and less than 11.4 pg of nucleic acid (equivalent to total nucleic acid from 19 ng of tissue) in the case of field-collected Brassica. The findings illustrate highly sensitive detection of MLOs in both field-grown and in vitro micropropagated infected plants.     

Determination of trace elements in standard reference materials by the ko-standardization method

Biological Trace Element Research - The ko-standardization method is suitable for routine multielement determinations by reactor neutron activation analysis (NAA). Investigation of NIST standard...