Locomotory and stridulatory circadian rhythms in the cricket, Teleogryllus commodus

Male crickets of the species Teleogryllus commodus express circadian rhythms in both their stridulatory and locomotory behaviours. Both forms of activity show the same free-running period (τ) in either DD (23·4 hr) or LL (25·1 hr). Although some overlap is seen between periods of locomotion and stridulation, the majority of each activity is found in different phases of the circadian cycle: locomotion occurs mainly in the subjective day and stridulation in the subjective night. Entraining LD cycles with photoperiods of 12 hr produce exogenous effects that can obscure endogenous components of the rhythms. Red light (λ>600 nm) causes the period to lengthen and RD cycles can entrain both rhythms. Single white light pulses of 2 or 6 hr did not produce significant phase shifts, but did cause τ to shorten when given in the subjective night. The significance of these observations is discussed. Given the results obtained to date, it is not likely that each rhythm is under the control of a separate circadian pacemaker.     

Dynamics of the pregnancy cycle in the tsetse Glossina morsitans

A normal pregnancy in tsetse involves the successful integration of larval development with maternal activity. At 25°C, ovulation in Glossina morsitans occurs 1 hr after the previous larviposition, the egg hatches on day 3·8 (1·57 mm length, 0·09 mg dry wt.), ecdysis to second instar occurs on day 4·9 (2·3 mm, 0·30 mg), the third instar cuticle is formed on day 6·8 (4·5 mm, 5·0 mg), and parturition occurs on day 9·0 (6·0 mm, 10·0 mg). Melanization of the in utero third instar follows a regular sequence over a 2 day period. Parturition follows a circadian pattern with a peak 9 hr after lights on (12 hr daily photophase). All instars receive nutriment from the female's milk gland. During early pregnancy the rate of milk synthesis is greater than rate of uptake by the larva, thus causing expansion of the secretory reservoirs. After day 6, the volume of the secretory reservoirs decreases, but as is indicated by nuclear volume and larval growth the rate of synthesis remains high until day 8. Feeding activity of the adult female is maximal on day 1, levels off at 60 per cent up to day 6, and then declines sharply towards the end of pregnancy. Oöcyte development proceeds in phase with larval development and thus minimizes a lag period between successive pregnancies.     

A three‐phase excess post‐exercise oxygen consumption in Atlantic salmon Salmo salar and its response to exercise training

The recovery of oxygen uptake to the standard metabolic rate (SMR) following exhaustive chasing exercise in Atlantic salmon Salmo salar parr occurred in three phases (rapid, plateau and slow). The initial recovery phase lasted 0·7 h and contributed 16% to the total excess post‐exercise oxygen consumption (EPOC). It was followed by a longer plateau phase that contributed 53% to the total EPOC. The slow recovery phase that completed recovery of SMR, which has not been reported previously, made a 31% contribution to the total EPOC. The plasticity of EPOC was demonstrated in exercise‐trained fish. Exercise training increased EPOC by 39% when compared with control fish (mean ± S.E., 877·7 ± 73·1 v . 629·2 ± 53·4 mg O₂ kg^?1, d.f. = 9, P <  0·05), with the duration of the plateau phase increasing by 38% (4·7 ± 0·58 v . 3·4 ± 0·16 h, d.f. = 9, P <  0·05) and the contribution of the slow phase to the total EPOC increasing by 80% (173·9 ± 23·9 v . 312·5 ± 50·4 mg O₂ kg^?1, d.f. = 9, P  < 0·05). As a result, the combination of the plateau and slow phases of exercise‐trained fish increased by 47% compared with control fish (756·6 ± 71·4 v . 513·6 ± 43·1 mg O₂ kg^?1; d.f. = 9, P  = 0·01). To substantiate the hypothesis that the plateau and slow recovery phase of EPOC was related to general metabolic recovery following exhaustive exercise, the time‐course for recovery of SMR was compared with previously published metabolite recovery profiles. The final phase of metabolic recovery was temporally associated with the final phases of gluconeogenesis, lactate oxidation and muscle intracellular pH regulation. Therefore, the plasticity of the latter phase of EPOC agreed with the known effects of exercise training in fishes.     

Temporal relationships between leaving food, ecdysone release, mucoprotein extrusion and puparium formation in Drosophila virilis

The time sequence of various developmental processes at the end of larval life in Drosophila virilis larvae is reported. If reared at 25·3°C the larvae leave their food about 140 hr after oviposition; 6·6 hr later ecdysone release occurs, while 8·5 to 9 hr after leaving food the mucoprotein, synthesized and stored in the salivary gland cells, is extruded into the lumen of the gland. Puparium formation takes place 11·2 hr after leaving food. Changes in the puffing activity are correlated with these processes.     

ANALYSIS OF THE PROLIFERATION KINETICS OF BURKITT'S LYMPHOMA CELLS

The in vitro proliferation kinetics of a cell line derived from a patient with American Burkitt's lymphoma were investigated at three different growth phases: lag (day 1), exponential (day 3) and plateau (day 5). The growth curve, labeling and mitotic indices, percentage labeled mitosis (PLM) curves and DNA content distributions were determined. The data obtained have been analysed by the previously developed discrete-time kinetic (DTK) model by which a time course of DNA distributions during a 10-day growth period was characterized in terms of other cell kinetic parameters. The mean cell cycle times, initially estimated from PLM curves on days 1, 3 and 5, were further analysed by the DTK model of DNA distributions and subsequently the mean cell cycle times with respect to DNA distributions during the entire growth period were determined. The doubling times were 39·6, 31·2 and 67·2 hr, respectively, at days 1, 3 and 5. The mean cell cycle time increased from 23·0 to 37·7 hr from day 3 to day 5 mainly due to an elongation of the G₁ and G₂ phases. A slight increase in the cell loss rate from 0·0077 to 0·0081 fraction/hr was accompanied by a decrease in the cell production rate from 0·0299 to 0·0184 fraction/hr. This calculated cell loss rate correlated significantly with the number of dead cells determined by trypan blue exclusion. Analysis of the number of dead cells in relation to the cell cycle stage revealed that a majority of cell death occurred in G₁ (r= 0·908; P < 0·0001). There was a good correlation between the in vitro proliferation kinetics at plateau phase of this Burkitt's lymphoma derived cell line and the in vivo proliferation kinetics of African Burkitt's lymphoma (Iversen et al., 1974), suggesting the potential utility of information obtained by in vitro kinetic studies.     

Effect of temperature and photoperiod on the induction of diapause in the mite Metaseiulus occidentalis

Diapause in a predaceous mite, Metaseiulus occidentalis, from a Californian vineyard population is a photoperiodically induced, facultative, adult reproductive diapause in females. The laboratory-determined critical photophase at 19°C was estimated at 11·2 hr. At 16°C, the critical photophase under laboratory conditions was approximately 11·6 hr. Temperature influenced the photoresponse of M. occidentalis so that diapause was entirely averted at temperatures of 22, 25, and 30°C. Aestival diapause at higher temperatures and long photophases was lacking. Development was continuous under constant darkness at all the temperatures tested. Diapause termination in laboratory-reared mites occurred spontaneously under the inductive conditions. Under constant 19°C temperatures, females responded to photophases so that diapause was terminated most rapidly under a 16 hr photophase (in 18·6 days); the 12 and 8 hr photophases, at this temperature, were next in their effectiveness, with 27·9 and 73·0 days, respectively, required for termination.     

Reproduction of Lumbricillus rivalis (Levinsen) in laboratory cultures and in decaying seaweed

The cocoon production of 144 Lumbricillus rivalis cultured in pairs at 10 ± 1 °C was high over the first 2 weeks of breeding activity and then declined, chiefly because of high mortality. Cocoon deposition lasted for between 1 and 16 weeks, eight pairs of worms producing cocoons for 9 weeks and one pair for 16 weeks. During the total period of cocoon deposition over 9000 eggs (mean 17·4 per cocoon) were deposited. Two decaying wrack bed populations of L. rivalis showed a low level of cocoon and egg production in autumn, rising to an annual maximum in late winter/early spring. In these populations the mean egg content varied seasonally from 17·1 to 47·8 eggs per cocoon. When cocoons in the laboratory were transferred from the site of deposition to incubation dishes 31% hatched, but those left in the substrate showed a 92% hatch. In the naturally occurring populations 19% of the cocoons detached from seaweed fronds hatched, but 62% of those left in situ. Eggs and worm embryos developed to relatively late stages in most cocoons, whatever the rate of hatching; development often continued for up to 2 months after deposition without hatching. Over 50% of the fertile eggs in cocoons from decaying wrack hatched and developed to 5 mm worms.     

THE PROLIFERATION KINETICS OF NHIK 1922 CELLS IN VITRO AND IN SOLID TUMOURS IN ATHYMIC MICE

The proliferation kinetics of cells of the line NHIK 1922 grown in vitro and as solid tumours in the athymic mutant nude mouse has been studied. In vitro, growth curves were determined for exponentially growing populations and for populations synchronized by mitotic selection. The phase durations for these populations were determined by flow cytofluorometric measurements of DNA-histograms and pulsed incorporation of [³H]TdR respectively. The generation time and the phase durations for synchronized populations were found to be about equal to those for exponentially growing populations. The duration of the phases G₁, S and G₂+ M was found to be 8·5–9·5, 11·0–12·0 and 6·0–6·5 hr respectively, i.e. the generation time was 26·5–27·0 hr. The proliferation kinetics in vivo were studied by flow cytofluorometry and by the technique of percentage labelled mitoses. The median duration of S-phase and (G₂+ M)-phase in vivo was found to be approximately the same as that observed in vitro, while the median duration of G₁-phase was found to be approximately 5 hr longer in vivo than under the present in vitro growth conditions. The growth fraction in vivo was estimated to be approximately 50%. The non-proliferative compartment of the tumour cells was found to consist mainly of cells with the DNA-content of cells in G₁-phase. It is concluded that the reduced rate of proliferation of NHIK 1922 cells in vivo is correlated with alterations in the duration of G₁-phase and, hence, the proportion of cells in G₁-phase.     

Water exchange and effect of water vapour activity on metabolic rate in the dust mite, Dermatophagoides.

Oxygen consumption by Dermatophagoides farinae was found to vary with temperature and water vapour activity. The relationship between temperature and O₂ consumed/hr per mite was first order. Q₁₀'s were equal to exp (k 10°C) and were found to be 3·04 and 2·49 for 1 to 6 and 6 to 22 hr monitoring periods respectively. A significant difference between O₂ consumed/hr per mite for 1 to 6 and 6 to 22 hr monitoring periods was found. Inactivity of mites explained 29·6 and 31·8 per cent of this reduction. Dehydrating conditions and reduced permeability of the water and gas exchange surface explained a further reduction to 58·7 and 60·8 per cent.     

Cell Cycle Kinetics of Aerated, Hypoxic and Re-Aerated Cells In Vitro Using Flow Cytometric Determination of Cellular Dna and Incorporated Bromodeoxyuridine

Abstract. The effects of extreme hypoxia on cell cycle progression were studied by simultaneous determination of DNA and bromodeoxyuridine (BrdU) contents of individual cells. V79-379A cells were pulse-labelled with BrdU (1 μM, 20 min, 37°C) and then incubated for up to 12 hr in BrdU-free medium under either aerated or extremely hypoxic conditions. After the incubation interval (0-12 hr), the cells were trypsinized and fixed in 50% EtOH. Propidium iodide and a fluorescein-labelled monoclonal antibody to BrdU were then used to quantify DNA content and incorporated BrdU, respectively. Measurements in individual cells were made by simultaneous detection of green and red fluorescence upon excitation at 488 nm using flow cytometry. Bivariate analysis revealed progression of BrdU-labelled cells in aerated cultures out of S phase, into G₂ and cell division, with halving of mean fluorescence, and back into S phase by approximately 9 hr after the BrdU pulse. Hypoxia immediately arrested cells in all phases of the cell cycle. Both the DNA distribution and the bivariate profile of cells that were fixed from 2 to 12 hr after induction of hypoxia were identical to the 0 hr controls. the percent of cells with green fluorescence in a mid-S phase window remained 100% and the mean fluorescence of these cells remained at control (0 hr) levels. This indicates that, under hypoxic conditions, cells were moving neither into nor out of S phase. Cultures that had been hypoxic for 12 hr exhibited an increasing rate of BrdU uptake with time after re-aeration. Re-aerated cells were able to complete or initiate DNA synthesis, but their rates of progression through the cell cycle were markedly reduced. A large fraction of cells appeared unable to divide up to 12 hr following release from hypoxia.     

Evaluation of filter paper as a means of transporting inactivated Gram-negative non-fermentative bacteria and Haemophilus spp. for identification using the MALDI-TOF MS system

This study aimed to evaluate the filter paper as a means to transport inactivated Gram-negative non-fermentative (GNNF) bacteria and Haemophilus spp. for analysis using MALDI-TOF MS. A total of 133 isolates were evaluated and the analysis of each isolate was performed directly from original bacterial colony and in filter paper after the processing. To evaluate the agreement between the identification performed directly from the colony and after impregnation in filter paper, we assign the scores: >2·3 as excellent (E); 2·0 to 2·3 as very good (VG); 1·7–1·99 as good (G); <1·7 as unidentified (U). The divergences were classified as: Minor Divergence, Intermediate Divergence and Major Divergence. A total of 80 isolates transported in the filter paper disks presented full category concordance; 39 isolates presented Minor Divergence; 4 isolates present Intermediate Divergence; 4 isolates present Major Divergence and 6 isolates present better results after impregnation in filter paper. The proposed methodology of bacteria transportation presented a sensitivity of 96·9% and a specificity of 100%. The filter paper as a means to transport and storage of inactivated GNNF and Haemophilus spp. may be considered a potential tool for faster, more accurate, biosafe and less-expensive identification.     

Initiation and maintenance of cocoon spinning behaviour by saturniid silkworms

Larvae of Antheraea pernyi and Hyalophora cecropia terminate the feeding phase of the fifth instar by purging the alimentary tract. This occurs in the morning under artificial illumination schedules and precedes the initiation of spinning by a species-specific time interval. Infusion of β-ecdysone into H. cecropia late in the feeding phase may, under certain conditions, provoke premature gut purging or terminate spinning by causing premature metamorphosis. Experiments in which spinning A. pernyi were stripped of their cocoons at various stages of construction confirmed that caterpillars initiated the spinning of a second cocoon at the same point in the behavioural repertoire where they had been interrupted. The rapid turning involved in cocoon impregnation behaviour was executed only in the confines of a cocoon, and required that the hindgut be both distended by exudate and free to expel it. Severance of the ventral nerve cord anterior to the terminal ganglion also eliminated impregnation behaviour. Cyclic turning of the caerpillar in the cocoon persisted after spinneret occlusion or silk gland excision, but at a markedly depressed frequency.     

Photoperiodic time measurement in the aphid Megoura viciae

Megoura produces parthenogenetic virginoparae in long day conditions, gamic oviparae in short days. The nature of this photoperiodic response has been analysed by rearing parent apterae in a wide range of circadian and non-circadian light cycles. By varying the light and dark components independently in a two-component cycle it has been established that the time measuring function is associated primarily with the dark period. There is no evidence that an endogenous circadian oscillation is implicated: thus (a) the ‘short day’ response is abolished by ‘night interruptions’ positioned in the early or late night. But this bimodal response pattern remains unchanged when the duration of the ‘main’ photoperiod is varied from ca. 6 hr to at least 25·5 hr. The stability of the maxima within the scotophase is inconsistent with the ‘coincidence’ models of photoperiodic timing that have been proposed. It is suggested that the essential timing process operates on the hour-glass principle, beginning anew with the onset of each period of darkness; (b) night interruption experiments employing very long (up to 72 hr) scanned dark periods yielded response maxima explicable in terms of the hour-glass hypothesis but did not reveal any circadian relationship between the maxima.The ‘dark reaction’ comprises a sequence of four stages, definable by the effects of light. Stage 1, extending from dark hr 0 to ca. 2·5, is fully photoreversible: at the next dark period the entire timing sequence is repeated up to the 9·5 hr critical night length. Towards the end of stage 1 reversibility is gradually lost and after a light interruption the reaction is resumed from a later time equivalent than dark hr 0; the subsequent critical night length is therefore reduced. The extent of the photoreversal is related to light duration. The period of maximum light insensitivity (stage 2) is attained at the end of the fourth hour. From ca. dark hr 5 to just short of the critical night length light exerts an increasingly promotive action which favours the production of virginoparae. This dark process is not photoreversible. Stage 4, which begins at hr 9·5, marks the end of the timing sequence. Light will not then annul the non-promotive action of the previous long night.Light has three effects which are determined by its duration and position within the cycle. The two terminal effects, mentioned above, are associated with the interception of dark stages 1 and 3 by either short (1 hr) or longer photoperiods. Light also prepares or primes the dark period timer. Thus the critical length is increased, and timing accuracy lost, if the preceding photoperiod is less than ca. 6 hr. Light during stage 4 has a priming action but no terminal function. Repeated cycles are ‘read’ in various ways, depending on the cycle structure. For example, if light intercepts stage 3, a two-component cycle is interpreted as the overlapping sequence light/dark/light. One and the same photoperiod then acts terminally in respect of the preceding dark period and as a primer for the next dark period.There is also a mechanism for summing the promotive effects produced by repeated interruption of dark stage 3. With complex (four-component) cycles both halves of the same cycle may contribute. ‘Product accumulation’ falls below threshold if the frequency of presentation of a given promotive cycle is too low. This occurs if there are very long, relatively non-promotive dark components. Such cycles are accepted as ‘continuous darkness’.     

An isotonic saline for the adult blowfly, Phormia regina, and its application to perfusion experiments

Measurements have been made of Na (119 mM), K (5·6 mM), and Ca (2·4 mM) concentrations and total osmotic pressure (487 mOs/kg) of blood of adult Phormia regina. From these data an isotonic saline has been constructed which can be coupled successfully with a newly described total perfusion technique. Using this method it has been shown that adult male Phormia 5 days after emergence recover 50 per cent of their blood trehalose within 12 hr after total perfusion, and are back to normal with reference to this carbohydrate between 24 and 48 hr.     

A comparative study of flight performance and fuel utilization as a function of age in females of Florida mosquitoes

Sugar-fed females of 7 species of Florida mosquitoes were flown for 4·5 hr on a flight-mill system twice a week during their life span and analysed for flight performance (speed of flight during the first hour, the distance flown at the end of 4·5 hr flight period, and per cent reduction in flight speed of the fourth hour as compared to the first hour) and for utilization of haemolymph sugars, glycogen, and triglycerides reserves.Species-specific differences occurred in 50 per cent survival age and flight performance. Aedes taeniorhynchus, Mansonia titillans, Culex nigripalpus, Psorophora confinnis, and A. sollicitans exhibited maximum flight potential during 2 to 8 weeks after emergence, as compared with only 1 to 2 weeks in A. aegypti and Anopheles quadrimaculatus. This suggested that the former group of mosquitoes possessed a greater potential for dispersal by searching flights during their life span when compared with the latter group. Glycogen was the only energy reserve utilized during sustained tethered flight in all species. The energy requirements as calculated from depletion of glycogen during sustained flight for 4·5 hr in different species varied from 0·06 to 0·09 cal/1000 m or 16 to 32 cal/hr per g. The considerably lower values of energy expended, on the average of 16 to 22 cal/hr per g in C. nigripalpus, P. confinnis, A. sollicitans, and A. aegypti, compared with 30 to 32 cal/hr per g in A. taeniorhynchus and M. titillans, is most probably due to the substantially lower speed of the former group of mosquitoes, 1000 to 1500 m/hr, than in the latter group of mosquitoes, 1500 to 2000 m/hr. A. sollicitans and M. titillans started to show wing abrasion and distinct signs of senescence during the last 2 to 3 weeks of their life span.Non-flown females of different species maintained on sugar ab lib. achieved maximum levels of glycogen and triglycerides reserves during the second week and they maintained these levels for the major portion of their life span, after which the levels of these reserves showed a distinct decline. It is suggested that this stabilization and decline of the energy reserves control longevity and flight potential in each mosquito species.     

Composition,synthetic and cytolytic activities of Galleria mellonella silk glands during the last-larval instar under the action of juvenile hormone

Within the first 48 hr of the last-larval instar of Galleria mellonella the silk glands grow but silk production is restrained. This ‘preparatory phase’ of the glands is probably maintained by juvenile hormone. Silk production and accumulation are stimulated in the ‘accumulation phase’ between 60 and 132 hr by unknown factors in the absence of juvenile hormone. The rate of RNA synthesis culminates at 84 hr but the RNA content increases until the end of cocoon spinning at 144 hr. In the following ‘regression phase’ (144–160 hr), when the glands exhibit high activities of acid and alkaline DN-ases and of acid phosphatase, the RNA and protein contents rapidly decrease, but that of DNA remains high. This phase is typical of moulting insects, is independent of juvenile hormone, and seems to be caused either by an increase in ecdysteroids or by lack of nutrients. The following ‘degeneration phase’ occurs when the surge of ecdysteroids terminates the larval-pupal transformation. Disintegration of silk glands by autolysis and phagocytosis is completed after pupal ecdysis (180 hr). Treatment of larvae with a juvenoid (ZR 512) at 48 or 132 hr in the last instar dramatically alter the composition, synthetic and cytolytic activities of silk glands. At the next ecdysis the glands attain a state very similar to that of the preparatory phase. They are capable of intensive silk production and completion of developmental cycle when the supernumerary larvae prepare for pupation. The results indicate that juvenile hormone can reverse the development of the silk glands.     

Aflatoxin contamination of Virginia peanuts for the crop-years 1982–1986

To establish those environmental conditions which promote the growth of aflatoxin (AFT)-producing Aspergillus spp. on peanuts, a four-year (1982–1986) investigation was undertaken to examine possible relationships between air temperature (AT), precipitation (P), and AFT contamination of stored nuts. The mean percentages of nuts that possessed various AFT levels for the years 1982–1986 (June–July) ranged from 74·2 to 88·0 for 0–4 ppb, 6·3 to 14·9 for 5–15 ppb, 2·4 to 5·9 for 16–25 ppb, 2·3 to 6·4 for 26–100 ppb, and 0 to 4·7 for > 100 ppb. The mean percentages for the years which exceeded USDA/FDA regulations were 7·1 (1982–1983), 7·6 (1983–1984), 11·6 (1984–1985), and 17·0 (1985–1986). Examination of the mean percentage > 15 ppb for each month during these four years revealed that the following months fell within that range; Septtember, November, December, January, February, and May (1982–1983); July, October, April, and June (1983–1984); August, and June, (1984–1985); and July, April, and May (1985–1986). Comparisons of pooled-AFT levels, rainfall, and temperature over four years suggested a ‘better fit’ between mean monthly P and mean percentage AFTs > 15 ppb, than between the latter and mean monthly AT. However, application of a predictor equation suggested a correlation between AFT levels and monthly AT.     

Misunderstanding on germination sensu stricto leads us to a false positive germination-dormancy balance in diaspores of Paepalanthus chiquitensis Herzog (Eriocaulaceae), a threatened everlasting flowering species

Although germination sensu stricto and germination–dormancy balance are essential to each other, few reports demonstrate the effects of their relationship on patterns of seed–seedling transition. We studied this relationship by using diaspores of Paepalanthus chiquitensis, a threatened everlasting flowering species. We assessed three aspects: (a) water dynamics in germinating diaspores, (b) thermal stimulation (35, 40, 50, 60 and 70°C for 30 min) and (c) imbibition (4 hr) in growth stimulators (100, 200 or 300 mg · L⁻¹ GA₃; 0.1% KNO₃). Our findings demonstrate that there are no barriers in the diaspore for diffusion. Additionally, there is high variability in diaspore permeability, and the germination of the species has two steps divided into five stages. These stages were defined by inflections on velocity in water dynamics, which ranged from −0.05 to 0.05 g · hr⁻¹, where only the last stage (Phase V) is associated with the second step of germination sensu stricto. The imbibition phase was the shortest germination phase (1.3 hr), whereas the predominantly biochemical phase was the longest (5 days after sowing [DAS]). Germinability was high (77.5–86.5%), with high daily embryo protrusion (2.46–3.03 diaspores · day⁻¹). Protocorm emergence marked the end of the first step of germination sensu stricto (9 DAS), and first protocorm rupture (11 DAS) marked the end of the second step. The growth stimulus only concentrated the germination process, showing that the diaspores do not have primary dormancy. Knowing these diaspores’ peculiarities during germination sensu stricto avoids a false positive statement on the existence of diaspore dormancy.     

Preparation and crystal structure of bis(acetato)(trans-1,2-diaminocyclohexane)platinum(II)

The structure of the complex [Pt(trans-1,2-di- aminocyclohexane) (acetate)₂]·H₂O has been determined by X-ray diffraction. This racemic compound is orthorhombic, space group Aba2, a = 20.813(9), b = 7.926(5), c = 17.296(8) Å, Z = 8. The structure was refined on 1214 nonzero Cu Kα reflections to R = 0.028. The square planar environment of Pt includes the amino groups of the diamine in cis positions and oxygens from two monodentate acetates. The PtN and PtO distances average 2.00(3) and 2.02(3) Å, respectively. The bite of the diamine ligand imposes a NPtN angle of 85(1)°, whereas the small OPtO angle of 85(1)° probably results from packing effects. The average plane through the puckered cyclohexyl ring makes an angle of 19° with the PtN₂O₂ plane. The molecules are stacked by pairs along the b axis. The two molecules of each pair are 180° apart about the stacking axis, and form altogether four NH···O hydrogen bonds.     

Unusual occurrence of aldehydes and ketones in the defensive secretion of the tenebrionid beetle, Eleodes beameri

The defensive secretion of the tenebrionid beetle, Eleodes beameri, is quite unlike the benzoquinone and 1-alkene secretion of other species of Eleodes and Tenebrionidae. Twenty-three compounds were isolated from the secretion by gas-liquid chromatography (GLC) and 13 of these were identified by infrared, nuclear magnetic resonance, ultraviolet, and mass spectroscopy. Identified compounds were: 1-nonene (3·2%), 1-undecene (<0·5%), n-hexanal (15·6%), n-heptanal (0·9%), n-octanal (4·5%), trans-2-hexenal (2·0%), trans-2-heptenal (1·5%), trans-2-nonenal (28·6%), trans-2-decenal (3·4%), n-3-nonanone (0·5%), n-1-nonen-3-one (16·8%), methyl-1,4-benzoquinone (22·0%), and 1-hexanol (<0·5%). 1-Nonen-3-one is unique to E. beameri. A number of minor components remain unidentified. The morphology and ultrastructure of the glands were similar to other species of Eleodes. The gland reservoirs are a pair of strongly bilobed sacs with narrow exit ducts opening between abdominal sternites 7 and 8. There are two types of secretory cell units: Type 1 consisting of cells closely attached to the reservoir intima, with large, central vesicles drained by highly convoluted tubules. Type 2 units are composed of a pair of cells functioning together, the cuticular organelle from the microvilli-filled vesicle of the distal cell (2a) passing through the vesicle of the proximal one (2b) and then draining more or less directly into the reservoir via a cuticular tubule.