A series of experiments was carried out primarily between the 22nd of March and the 27th of June, on 60 Lacerta muralis maintained either under semi-natural conditions in large enclosures or in constant-temperature cabinets maintained at 17.5 degrees C, 20 degrees C, 22.5 degrees C and 27.5 degrees C with a natural photoperiod. Following an injection of tritiated thymidine, the animals were sacrificed at regular intervals and the rate of spermatogenesis was deduced from the progression of the radioactive front in the seminiferous epithelium. The following results were obtained: 1. The rate of spermatogenesis is temperature dependent and increases by a factor of approximately 1.2 per degree centigrade between 17.5 and 27.5 degrees C. The rate is seven times greater at 27.5 degrees C than at 17.5 degrees C. 2. Under semi-natural conditions the interval leptotene-spermatozooid lasts 70 days, slightly less than that found at a constant temperature of 22.5 degrees C. 3. Under semi-natural conditions the rate of spermatogenesis was similar to that in August-September, April-May and May-June which indicates that the lizards were able to maintain their body temperature at an equivalent level by behavioural temperature regulation during the greater part of their activity period. 4. Under semi-natural conditions, or at temperatures in excess of 22 degrees C, spermiogenesis lasts 1.8 times as long as meiosis. 5. At constant temperatures lower than 21 degrees C the development of the cellular lineage is aressted at the young spermatid stage. 6. Constant temperatures between 17.5 and 22.5 degrees C had no effect on the time of involution of the testis at the start of summer. 7. At low constant temperatures, secondary sexual characteristics regress before the usual time: after 4 weeks at 20 degrees C and after 8 weeks at 17.5 degrees C. An expected regression after 8 weeks produced after exposure to a temperature of 22.5 degrees C is probably due to factors other than temperature. 8. In the case of different individuals kept either under natural, semi-natural or experimental conditions, there was no close relationship observed between the time of involution of the seminiferous tubules and regression of secondary sexual characters. ters. 9. These results confirm the concept of endogenous control of sexual regression at the commencement of summer and argue in favour of 2 separate gonadotrophic hormones in reptiles.
Mesh-terms: Animals; English Abstract; Epididymis :: growth & development; Hibernation; Kidney :: anatomy & histology; Lizards :: physiology; Male; Meiosis; Seasons; Seminiferous Tubules :: cytology; Seminiferous Tubules :: growth & development; Sex Characteristics; Sperm Maturation; Spermatids :: ultrastructure; Spermatocytes :: ultrastructure; Spermatogenesis; Spermatozoa :: ultrastructure; Temperature; Testis :: anatomy & histology; Thymidine :: metabolism; Time Factors;
Other papers by authors:
L Jacquamet,
J Joly,
A Bertoni,
P Charrault,
M Pirocchi,
X Vernede,
F Bouis,
F Borel,
J P Périn,
T Denis,
J L Rechatin,
J L Ferrer
Groupe Synchrotron (GSY), Laboratoire de Cristallographie et Cristallogenèse des Protèines (LCCP), Institut de Biologie Structurale J.-P. Ebel, UMR5075 CEA-CNRS-University J. Fourier, 41 rue Jules Horowitz, 38027 Grenoble Cedex 1, France.
An upgraded version of the sample changer ;CATS'(Cryogenic Automated Transfer System) that was developed on the FIP-BM30A beamline at the ESRF is presented. At present, CATS is installed at SLS (three systems), BESSY (one system), DLS (two systems) and APS (four systems for the LSCAT beamline). It consists mainly of an automated Dewar with an assortment of specific grippers designed to obtain a fast and reliable mounting/dismounting rate without jeopardizing the flexibility of the system. The upgraded system has the ability to manage any sample standard stored in any kind of puck.
Département de psycho-éducation, université de Sherbrooke, 2500, boulevard de l'Université Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada. Eve-Marie.Bouchard@USherbrooke.ca
BACKGROUND: The co-occurrence of child victimization experiences is not a rare phenomenon. However, few studies have explored the long-term consequences of such experiences. Empirical studies present important methodological limitations, namely the fact that few studies have documented more than two forms of victimization, that they rely on non representative samples and have not used multivariate analyses. The present study aims to evaluate the specific contribution of each form of child victimization (sexual, physical and psychological) on the outcomes in adulthood. Moreover, the study explores the role of co-occurrence on these symptoms. METHODS: A phone survey was conducted with a representative sample of 804 adults from the province of Quebec. Households were randomly selected among those having a telephone. Sociodemographic variables, child victimization experiences (sexual, physical and psychological) and partner violence were evaluated to explore their links with psychological distress, post-traumatic stress symptoms and physical health of participants. RESULTS: Higher psychological distress in men is associated with younger age, lower education level and having experienced sexual and physical violence in childhood. For women, psychological distress is linked to younger age, having experienced partner violence, childhood physical and psychological violence. Only experiencing partner violence and childhood sexual and psychological victimization are linked to greater post-traumatic stress symptoms in men and women. Finally, lower education level and childhood sexual and physical victimization increase physical health problems for men, while for women, only lower education level contributes to the prediction. CONCLUSION: The results of this study show that experiencing more than one form of childhood victimization increases the negative outcomes in adulthood, underlying the relevance of considering the phenomenon of co-occurring victimization in the elaboration and dissemination of intervention programs.
Service de Gynécologie-Obstétrique, Hôpital Louis Mourier, Colombes.
The objective of this article is to describe the conditions under which very premature babies were born in the Paris region between June 1 and December 31, 1998, that is to say those born prior to reaching 33 weeks of term (SA) and/or having a birth weight less than 1500 grams. The study looked at all pre-term births, including medical terminations of pregnancy (TOP), occurring in one of the 135 maternity units in the Paris region. Between June 1 and December 31, 1998, 1337 mothers gave birth to babies prior to reaching 33 weeks of term (SA) and/or having a birth weight less than 1500 grams in 84 maternity units in the Paris region, 263 of which had a medical termination of pregnancy (20%). These mothers were older than average for the region (25% were 35 years old or older); 4.3% of them do not have social insurance coverage. The remaining 1074 mothers (excluding TOP) gave birth to 1290 children, of which 202 were stillbirths, 46 died in the labor ward and 1042 were admitted to a neo-natal unit. Of the same group of 1074 mothers, 195 (18%) had a multiple pregnancy--175 twins, 19 triplets, and 1 quadruplet 60% of them (599 women) who had very premature or low birth weight babies (excluding TOPs) delivered them in a tertiary perinatal centre (TPC). This proportion varies according to two variables: 1) the community in which the family lives (40% in the Seine-et-Marne department, the eastern region of Paris and a district without TPCs, to 70% in the Hauts-de-Seine, a northern district), and 2) whether the pregnancy is single (58.8%), twin (72.6%) or triple (84.2%). In utero transfer accounts for 62.7% of the mothers who delivered in TPC, who were transferred prior to delivery. This type of study is useful for measuring the implementation of the regionalisation high-risk perinatal care and access to adequate services. It clearly demonstrates that inequities in access to care exist for women by district of residence.
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J Environ Sci Health A Tox Hazard Subst Environ Eng. 2009 Oct ;44 (12):1298-305 19847718 (P,S,G,E,B,D)
Technologies for Water Management and Treatment Group, Department of Civil Engineering and Water Research Institute, University of Granada, Granada, Spain.
Inoculation of a submerged filter was carried out using three bacterial strains previously selected on the basis of their psychrotolerance and high denitrifying activity with the aim of apply selective inoculation to a submerged filter system for the denitrification of groundwater. Laboratory-scale assays were carried out at 5, 10 20 and 30 degrees C. Surface scanning microscopy was used to evaluate the capacity of each inoculant to colonise the support. In all cases a biofilm in the initial stages of development was observed, with abundant connection material and cells in division. Increase in temperature had a negative effect on colonisation evolution, motivated by the use of psychrotolerant bacteria. Each inoculant presented a different colonisation optimum, but always at temperatures under 20 degrees C. To monitor system setup, concentrations of total nitrogen, nitrate and nitrite after treatment were measured. In most cases, the stabilisation phase was observed to be longer at lower temperatures, independently of the inoculant employed. However, at 5 degrees C, only one of the inoculants reached steady-state phase with total nitrogen elimination. In all the assays, an accumulation of nitrite was observed during stabilisation phase. At lower temperatures, maximum concentrations of nitrite were greater and were reached after longer operation times. Use of selective inoculants was shown to promote subsequent development of a stable biofilm achieving efficient elimination of nitrate from the influent. This occurs regardless of the inoculant employed, except at a temperature of 5 degrees C, at which the type of inoculant conditions system setup. However, colonisation capacity of the inoculant at low temperatures is not a determining factor.
Melanie J Bugler,
Stephen T Grimes,
Melanie J Leng,
Simon D Rundle,
Gregory D Price,
Jerry J Hooker,
Margaret E Collinson
School of Earth, Ocean & Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK.
Experimental measurements of the (18)O/(16)O isotope fractionation between the biogenic aragonite of Viviparus contectus (Gastropoda) and its host freshwater were undertaken to generate a species-specific thermometry equation. The temperature dependence of the fractionation factor and the relationship between Deltadelta(18)O (delta(18)O(carb.)- delta(18)O(water)) and temperature were calculated from specimens maintained under laboratory and field (collection and cage) conditions. The field specimens were grown (Somerset, UK) between August 2007 and August 2008, with water samples and temperature measurements taken monthly. Specimens grown in the laboratory experiment were maintained under constant temperatures (15 degrees C, 20 degrees C and 25 degrees C) with water samples collected weekly. Application of a linear regression to the datasets indicated that the gradients of all three experiments were within experimental error of each other (+/-2 times the standard error); therefore, a combined (laboratory and field data) correlation could be applied. The relationship between Deltadelta(18)O (delta(18)O(carb.)- delta(18)O(water)) and temperature (T) for this combined dataset is given by:$${\rm T}=- 7.43(+ .87,- 1.13)*\Delta {\rm \delta };{18}{\rm O}+ 22.89(\pm 2.09)$$(T is in degrees C, delta(18)O(carb.) is with respect to Vienna Pee Dee Belemnite (VPDB) and delta(18)O(water) is with respect to Vienna Standard Mean Ocean Water (VSMOW). Quoted errors are 2 times standard error).Comparisons made with existing aragonitic thermometry equations reveal that the linear regression for the combined Viviparus contectus equation is within 2 times the standard error of previously reported aragonitic thermometry equations. This suggests there are no species-specific vital effects for Viviparus contectus. Seasonal delta(18)O(carb.) profiles from specimens retrieved from the field cage experiment indicate that during shell secretion the delta(18)O(carb.) of the shell carbonate is not influenced by size, sex or whether females contained eggs or juveniles. Copyright (c) 2009 John Wiley & Sons, Ltd.
School of Biological & Earth Sciences, Liverpool John Moores University, Liverpool L3 3AF, UK.
Little is known about the impact of increased metabolism on body temperatures of small ectotherms. We found that postprandial metabolic rates of 5g Anolis carolinensis lizards were elevated by factorial increases of 2.3+/-1. (mean+/-S. E.) at 26 degrees C and 3.8+/-2.1 at 30 degrees C over their fasting rates. Cloacal body temperatures exceeded environmental temperatures by a small amount in fasted individuals (26 degrees C: .3+/- .02 degrees C, 30 degrees C: .3+/- .02 degrees C), and by a significantly larger amount in fed individuals (26 degrees C: 1. +/- .06 degrees C, 30 degrees C: .8+/- .08 degrees C). We conclude that an increased metabolic rate due to specific dynamic action leads to a small but significant elevation of body temperature in this species. Comparisons with thermal increments reported for a large (750 g) varanid lizard suggest that body size has only a minor influence on body-air temperature differentials of ectotherms. This is consistent with theoretical predictions. Finally, endogenous heat production could help elevate body temperatures in the wild and therefore play a minor role in thermoregulation.
The optimum temperature for embryogenesis in Meloidogyne javanica lies between 25 and 30 C. Embryogenesis is slightly more rapid at 30 C (9-10 days), but more eggs complete development at 25 C (11-13 days). At temperatures of 25, 27.5, and 30 C, embryogenesis is about twice as rapid as at 20 C (23-25 days), and about four times as rapid as at 15 C (46-48 days). Time-lapse studies showed that the thermal optimum is similar throughout the different stages of embryonic development.
Longidorus africanus multiplication on tomato was highest at 29 degrees C. Few nematodes were recovered after 6 weeks at soil temperatures of 35 degrees C or below 23 degrees C. The time to egg hatching was shortest and the percentage of eggs hatching was highest at 29 degrees C. The minimum temperature and the heat sum above this temperature required for egg development were calculated to be 14.3 degrees C and 94.08 degree-days, respectively. The thermal times required for egg development by L. africanus and L. elongatus were nearly identical. For both species the product of the base temperature and the heat sum was near constant, and at a temperature of 22.3 degrees C the rates of egg development were equal.
We acclimated adults of Takydromus septentrionalis (northern grass lizard) from four localities (populations) under identical thermal conditions to examine whether local thermal conditions have a fixed influence on thermal preference and thermal tolerance in the species. Selected body temperature (Tsel), critical thermal minimum (CTMin), and critical thermal maximum (CTMax) did not differ between sexes and among localities in lizards kept under identical laboratory conditions for approximately 5 months, and the interaction effects between sex and locality on these measures were not significant. Lizards acclimated to the three constant temperatures (20, 25, and 35 degrees C) differed in Tsel, CTMin, and CTMax. Tsel, CTMin, and CTMax all shifted upward as acclimation temperature increased, with Tsel shifting from 32. to 34.1 degrees C, CTMin from 4.9 to 8. degrees C, and CTMax from 42. to 44.5 degrees C at the change-over of acclimation temperature from 20 to 35 degrees C. Lizards acclimated to the three constant temperatures also differed in the range of viable body temperatures; the range was widest in the 25 degrees C treatment (38.1 degrees C) and narrowest in the 35 degrees C treatment (36.5 degrees C), with the 20 degrees C treatment in between (37.2 degrees C). The results of this study show that local thermal conditions do not have a fixed influence on thermal preference and thermal tolerance in T. septentrionalis.
Multiple advertising sexual traits may either advertise different characteristics of male condition or be redundant to reinforce reliability of signals. Research has focused on multiple visual traits. However, in animals that use different multiple additional sensory systems, such as chemoreception, different types of traits might have evolved to signal similar characteristics of a male quality using different sensory channels. We examined whether ventral coloration and chemicals in femoral gland secretions of male common wall lizards, Podarcis muralis, are affected by their health state (blood-parasite load and cell-mediated immune response). Our results indicated that less parasitized lizards had brighter and more yellowish ventral colorations and also femoral secretions with higher proportions of two esters of octadecenoic acid. In addition, lizards with a greater immune response had more saturated coloration and secretions with higher proportions of octadecenoic acid methyl ester. We suggest that these signals would be reliable because only healthier males seemed able to allocate more carotenoids to coloration and presumably costly chemicals to secretions. The use of multiple sensory channels may provide more opportunities to signal a male quality under different circumstances, but also may reinforce the reliability of the signal when both types of traits may be perceived simultaneously.
Convoluted seminiferous tubules and spermatozoa of albino rats under conditions of thermal exposure were studied by scanning electron microscopy. Exposure at 40 degrees C (in a thermostat) for 1 h caused significant changes in spatial structure of the tubules and spermatozoa. The tubular lumens acquired an irregular shape. The integrity of the spermatid layer was disrupted. The spermatozoon heads were deformed, the tails became bifurcated and convoluted. The appearance of erythrocytes on the spermatid surface attested to impairment of the blood-testis barrier.
The influence of roasting conditions on the acrylamide content and on the color of roasted almonds of 3 cultivars was investigated. The temperature inside the almond kernel, the water content, the color, and the acrylamide content were determined at different roasting temperatures and times. The formation of acrylamide started only when the kernel temperature had exceeded approximately 130 degrees C. The activation energy for the acrylamide formation during the roasting of almonds was 123 kJ.mol(-1). The color as measured by the degree of brightness correlated well with the acrylamide content as acrylamide content increased with increasing darkness. Therefore, control of roasting temperature presents the critical factor for limiting the acrylamide concentration in the final product. At constant roasting conditions, almonds with higher initial moisture content contained less acrylamide after roasting, which is probably due to the influence of moisture on the development product temperature during roasting.
The ability of the aphid pathogenic fungus Pandora neoaphidis to remain active in the absence of a resting stage through a combination of continuous infection and as conidia deposited on soil was assessed alongside the potential for planted field margins to act as a refuge for the fungus. P. neoaphidis was able to infect the pea aphid, Acyrthosiphon pisum, when maintained under controlled conditions that simulated those that occur seasonally in the UK. Although there was a significant inverse relationship between temperature and time-to-kill, with death occurring after 4.2, 6.9 and 13.6 days when maintained under fluctuating summer, autumn and winter temperatures, respectively, there were no additional statistically significant effects of photoperiod. The activity of inoculum on soil was indirectly assessed by baiting with A. pisum. Under controlled conditions P. neoaphidis remained active on soil and was able to infect aphids for up to 80 days. However, the percentage of aphids that became infected decreased from 76% on day 1 to 11% on day 80. Whereas there was little difference in the activity of conidia that had been maintained at 4 degrees C and 10 degrees C, activity at 18 degrees C was considerably reduced. Under field conditions the activity of inoculum was strongly influenced by season. On day 49 there was little or no activity during spring, summer or winter. However, during autumn a mean proportion of .08 aphids still became infected with P. neoaphidis. Margin type did not affect the activity of conidia nor was there a difference in activity between blocks that had regenerated naturally and those that had been planted. These results suggest that P. neoaphidis can infect aphids and remain active on soil under the abiotic conditions that occur seasonally in the UK and that this fungus may be able to persist annually without a resting stage.
