A model for "splitting" of running-wheel activity in hamsters

Splitting of locomotor activity rhythm in hamsters occurs when the animals are exposed for several weeks to constant light. The authors propose a mathematical model that explains splitting in terms of a switch in the sign of coupling of two oscillators, from positive to negative, due to long-term exposure to constant light. The model assumes that the two oscillators are not identical and that the negative coupling strengths achieved by each individual animal are variable. With these assumptions, the model provides a unified picture of all different splitting patterns presented by the hamsters, provides an explanation for why the two activity components cross each other during many patterns, and explains why the phase difference achieved by the split components is often near 180 degrees.     

Mammal road‐type associations in Kruger National Park,South Africa: Common mammals do not avoid tar roads more than dirt roads

The majority of Africa''s parks and conservation areas have a vast road network, facilitating motorized vehicle game viewing. These roads have an influence that is both road type‐ and species‐specific, on the surrounding ecosystem. Due to their higher traffic volumes, we hypothesized that tar roads and their immediate surrounds within the Kruger National Park, South Africa, are avoided to a greater extent by medium‐to‐large mammals than comparable dirt roads in the park. We systematically recorded the presence of medium‐to‐large mammal species from our vehicle, recording data at 401 tar and 369 dirt road stops in the Kruger National Park. In addition to species presence, we also estimated the proximity of animals to the road, as well as herd sizes. Our results indicate an equal likelihood of viewing the commonly recorded medium‐to‐large mammal species from both road types. The likelihood of observing larger herd sizes was also similar between tar and dirt roads for the three most commonly observed species, African elephant (Loxodonta africana), impala (Aepyceros melampus), and plains zebra (Equus quagga), and the likelihood of viewing impala and zebra close to the road also did not differ between tar and dirt roads. However, elephant was observed more often close to tar roads, compared to dirt roads. We interpreted this as the result of potentially increased woody cover associated with more water runoff in close proximity to tar roads compared with dirt roads. Our results not only have ecological significance, supporting the notion that many of the park''s species are habituated to human infrastructure, but also management implications, informing park officials about the influence of road traffic and road type on wildlife distributions.     

Studies of brain myelin in the "quaking mouse"

Myelin was isolated from the brains of "quaking" and littermate control animals and its composition was determined. The brains of quaking animals contained approximately one-fourth as much myelin as the control animals. There were qualitative as well as quantitative differences between the myelin from the two groups. By continuous cesium chloride gradient flotation it was shown that the myelin from the quaking animals consisted solely of a band corresponding to the heavier and smaller of the two bands found in normal controls. Cholesterol and glycolipids were lower and phospholipids (mainly phosphatidylcholine) and protein were higher in quaking animals than in controls. Also, phosphatidal-ethanolamine was decreased, and several consistent differences in the fatty acids (both unsubstituted and hydroxy) and aldehydes of the component lipids were found. In general there were smaller amounts of monounsaturated fatty acids in quaking animals. We suggest from these findings that myelin in the quaking mouse has certain compositional similarities with juvenile myelin, but it may be an abnormal type of myelin.     

Assessment of "impulsive" behavior by the method with time calculation

In this paper the problem of "impulsive" and "self-control" behaviour in animals and the experimental models for their assessment are discussed. It is pointed out that a widely accepted model for assessment of impulsive behaviour in animals predominantly measures their ongoing properties of impulsivity/self-control independently on belonging them to the certain types of higher nervous activity. In contrary, our model at the first instance assesses the typological characteristics of animals, including impulsivity and self-control, by their abilities to perform or not to perform an appropriate behaviour. The differences in the data obtained by these two different models and the possible reasons for it are discussed.     

Phylogenetic diversity and cosymbiosis in the bioluminescent symbioses of "Photobacterium mandapamensis"

"Photobacterium mandapamensis" (proposed name) and Photobacterium leiognathi are closely related, phenotypically similar marine bacteria that form bioluminescent symbioses with marine animals. Despite their similarity, however, these bacteria can be distinguished phylogenetically by sequence divergence of their luminescence genes, luxCDAB(F)E, by the presence (P. mandapamensis) or the absence (P. leiognathi) of luxF and, as shown here, by the sequence divergence of genes involved in the synthesis of riboflavin, ribBHA. To gain insight into the possibility that P. mandapamensis and P. leiognathi are ecologically distinct, we used these phylogenetic criteria to determine the incidence of P. mandapamensis as a bioluminescent symbiont of marine animals. Five fish species, Acropoma japonicum (Perciformes, Acropomatidae), Photopectoralis panayensis and Photopectoralis bindus (Perciformes, Leiognathidae), Siphamia versicolor (Perciformes, Apogonidae), and Gadella jordani (Gadiformes, Moridae), were found to harbor P. mandapamensis in their light organs. Specimens of A. japonicus, P. panayensis, and P. bindus harbored P. mandapamensis and P. leiognathi together as cosymbionts of the same light organ. Regardless of cosymbiosis, P. mandapamensis was the predominant symbiont of A. japonicum, and it was the apparently exclusive symbiont of S. versicolor and G. jordani. In contrast, P. leiognathi was found to be the predominant symbiont of P. panayensis and P. bindus, and it appears to be the exclusive symbiont of other leiognathid fishes and a loliginid squid. A phylogenetic test for cospeciation revealed no evidence of codivergence between P. mandapamensis and its host fishes, indicating that coevolution apparently is not the basis for this bacterium's host preferences. These results, which are the first report of bacterial cosymbiosis in fish light organs and the first demonstration that P. leiognathi is not the exclusive light organ symbiont of leiognathid fishes, demonstrate that the host species ranges of P. mandapamensis and P. leiognathi are substantially distinct. The host range difference underscores possible differences in the environmental distributions and physiologies of these two bacterial species.     

Men and Women in Southern Spain: "Domestic Power" Revisited

This article offers a definition of "domestic power" and attempts to operationalize this for comparative study of gender relations in southern Europe. It describes male-female relations in two stratified rural towns in Andalusia (southern Spain). The data show that working-class women in these towns, often united with their mothers, are able in many cases to prevail in domestic decision making despite opposition from their husbands. The article explores the cultural and psychological reasons for this apparent inversion of a constituted patriarchal ideal and the relative effect of social class upon male and female power asymmetries. The implications of limited access of male fieldworkers to Andalusian women are briefly addressed. Finally, these findings are discussed in the light of broader epistemological issues in gender study.     

Contamination detection by optical measurements in a real‐life environment: A hospital case study

Organic dirt on touch surfaces can be biological contaminants (microbes) or nutrients for those but is often invisible by the human eye causing challenges for evaluating the need for cleaning. Using hyperspectral scanning algorithm, touch surface cleanliness monitoring by optical imaging was studied in a real‐life hospital environment. As the highlight, a human eye invisible stain from a dirty chair armrest was revealed manually with algorithms including threshold levels for intensity and clustering analysis with two excitation lights (green and red) and one bandpass filter (wavelength λ = 500 nm). The same result was confirmed by automatic k‐means clustering analysis from the entire dirty data of visible light (red, green and blue) and filters 420 to 720 nm with 20 nm increments. Overall, the collected touch surface samples (N = 156) indicated the need for cleaning in some locations by the high culturable bacteria and adenosine triphosphate counts despite the lack of visible dirt. Examples of such locations were toilet door lock knobs and busy registration desk armchairs. Thus, the studied optical imaging system utilizing the safe visible light area shows a promising method for touch surface cleanliness evaluation in real‐life environments.     

Road size and carrion beetle assemblages in a New York forest

In many parts of the world, roads are the most common causes of forest fragmentation. We know roads can affect wildlife, but understand little the extent to which these effects depend on road type and use. We compared the effects of several road types upon a diverse, carrion frequenting beetle assemblage in rural New York State. We found no consistent effects of distance from road on the diversity, abundance or species density of beetles across road types. However, forests near highways and two-lane paved roads were significantly less diverse than were forests near dirt roads. The reduced diversity of beetles near roads was at least in part due to lower species turnover in space near dirt roads than near either type of paved roads. Our data suggest that all roads are not created equal and that comparably sized minimum-use paved roads have a substantially greater affect on fauna than dirt roads. Highways and two-lane paved roads appear to depress biodiversity even among relatively vagile animals like beetles.     

Circadian and photoperiodic effects of brief light pulses in male Djungarian hamsters

The effects of brief light pulses (1-60 min in duration) on the circadian rhythm of locomotor activity and/or the neuroendocrine-gonadal axis was investigated in male Djungarian hamsters. Exposure of hamsters free-running in constant darkness to a single 1-h pulse of light induced phase-dependent phase shifts in the rhythm of locomotor activity. The general shape of the "phase-response curve" was similar to that observed in other animals; phase-delays and phase-advances were induced by light pulses delivered in the early and late subjective night, respectively, while light pulses during the subjective day induced little or no phase-shift in the activity rhythm. Animals exposed for 7 days to 1-min of light during the night in animals otherwise exposed to 6L:18D resulted in increased levels of serum FSH and testicular weight. Daily exposure to two 1-h or two 10-min pulses of light (but not two 1-min pulses) for 10 days resulted in stable entrainment of the activity rhythm as well as testicular weight gains and serum FSH increases. When two 10-min pulses of light were presented 8 and 16 h apart, some animals showed a short-day entrainment pattern (i.e., locomotor activity confined to the long period of darkness) while other animals showed a long-day entrainment pattern (i.e., locomotor activity confined to the short period of darkness). Importantly, the stimulatory effects of light on neuroendocrine-gonadal activity were clearly dependent on the phase-relationship between the light pulses and the circadian rhythm of locomotor activity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Light entrainment and stimulation of the secretion of prolactin in rams

Light entrainment and stimulation of PRL release were studied in rams submitted to artificial light regimes: In a first experiment four groups of animals were submitted to light regimes with a period of 6, 4, 3 or 2 months respectively (T6 to T2 groups) and amplitude of 8-16 h of daylength. In all four groups PRL level was significantly correlated with daylength (r greater than 0.51; P less than 0.01). However in July, when temperatures were indeed high, an additional PRL increase was observed in the T6, T4 and T3 groups, although the role of temperature appears debatable. In a second experiment, animals were exposed daily to 8 hrs. of light given in two photofractions. The first fraction of 7 hrs. began at the same time as "dawn", and the second of 1 hr ended at the same time as "dusk" of the T6 group in the first experiment which served as control group. Correlation of plasma prolactin in rams receiving 8 h light in one or two photofractions was highly significant (r = 0.66; P less than 0.001). This suggests that rams measured daylength between two limits considered as "dawn" and "dusk" even if lights were turned off during part of this interval.     

Testosterone and group size in cliff swallows: testing the "challenge hypothesis" in a colonial bird

The "challenge hypothesis" states that increases in testosterone levels of male animals during the breeding season are directly related to the extent of intrasexual competition for resources or mates that they experience. Although often tested in territorial species, the challenge hypothesis has not been evaluated for colonial animals that live in groups of different sizes and that thus experience different intensities of intrasexual competition. We measured circulating testosterone levels of male and female cliff swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, where these birds nest in colonies of widely different sizes. Males had significantly higher testosterone levels than females, as expected. For males especially, there was a seasonal rise in testosterone levels early in the nesting cycle, corresponding to the period when birds were establishing nest ownership and egg laying, and then a fall as they switched to parental duties. Testosterone levels varied significantly with colony size; for both sexes, birds in larger colonies had higher levels of testosterone than those in smaller colonies when controlling for date. Age and body mass were not related to testosterone levels. Higher levels of testosterone for birds of both sexes in larger colonies probably reflect greater competition for matings, often extra pair, in the more social nesting situations. The results support the predictions of the challenge hypothesis.     

Moral sensibilities and moral standing: Caplan on xenograft "donors"

[I]nterest in animals as a source of organs and tissues for human beings remains strong. New developments in immunosuppression technology promise to lower the technical barriers to a routine use of nonhumans as organ donors, and the image of colonies of animals kept at the ready for supplying the growing human need for new organs seems a much more plausible scenario now than it did when broached by transplantation specialists in the Sixties. As Arthur Caplan has powerfully argued, the prospects that other sources of organs may resolve the supply problem are grim.... In the face of these "pro-xenograft" pressures, it becomes all the more signficant to assess arguments against the practice that rest on considerations of the moral status of the nonhumans from whom the organs are taken. To be sure, xenograft faces other moral difficulties -- for example, concerns about the quality of informed consent obtained for recipients, worries about the possibility that xenografting will serve as a vector by which new and possibly virulent viruses become established in humans, and problems about whether such spending is equitable in the light of other unresolved human needs. Yet whether we morally wrong animals in taking their organs and their lives remains a decidedly central issue here, one that cannot be finessed away by developing better informed consent procedures, better anti-viral strategies, or by situating transplantation medicine in a just health care system.     

Demography of the sessile rotifers, <Emphasis Type="Italic">Limnias ceratophylli</Emphasis> and <Emphasis Type="Italic">Limnias melicerta</Emphasis> (Rotifera: Gnesiotrocha), in relation to food (<Emphasis Type="Italic">Chlorella vulgaris</Emphasis> Beijerinck, 1890) density

Circadian rhythms occur widely amongst living organisms, often in response to diel changes in environmental conditions. In aquatic animals, circadian activity is often synchronised with diel changes in the depths individuals occupy and may be related to predator–prey interactions, where the circadian rhythm is determined by ambient light levels, or have a thermoregulatory purpose, where the circadian rhythm is governed by temperature. Here, these two hypotheses are examined using animal-attached accelerometers in juvenile freshwater sawfish occupying a riverine environment displaying seasonal changes in thermal stratification. Across seasons, diel patterns of depth use (shallow at night and deep in the day) tended to occur only in the late dry seasons when the water was stratified, whereas individuals were primarily shallow in the early dry season which featured no thermal stratification. Activity was elevated during crepuscular and nocturnal periods compared to daytime, regardless of the thermal environment. Our observation of resting at cooler depths is consistent with behavioural thermoregulation to reduce energy expenditure, whereas activity appears linked to ambient light levels and predator–prey interactions. This suggests that circadian rhythms in activity and vertical migrations are decoupled in this species and respond to independent environmental drivers.     

Protochlorophyllide oxidoreductase: "dark" reactions of a light-driven enzyme

The light-driven enzyme NADPH:protochlorophyllide oxidoreductase (POR) catalyzes the reduction of protochlorophyllide (Pchlide) to chlorophyllide (Chlide), a key regulatory step in the chlorophyll biosynthesis pathway. As POR is light activated, it allows intermediates in the reaction pathway to be observed by initiating catalysis with illumination at low temperatures, a technique that has recently been used to study the initial photochemistry. Here, we use low-temperature spectroscopy to show that the catalytic mechanism of POR involves two additional steps, which do not require light and have been termed the "dark" reactions. The first of these involves the conversion of the product of the initial light-driven reaction, a nonfluorescent radical species, into a new intermediate that has an absorbance maximum at 681 nm and a fluorescence peak at 684 nm. During the second dark step this species gradually blue shifts to yield the product, Chlide. The temperature dependence for each of these two processes was measured; the data revealed that these steps could only occur close to or above the "glass transition" temperature of proteins, suggesting that domain movements and/or reorganization of the protein are required for these stages of the catalytic mechanism.     

Carcass permanency time and its implications to the roadkill data

Roadkill studies are typically conducted without regard to the carcass permanency time on the highway, which may lead to underestimation of roadkill data, especially small animals that are quickly removed by scavengers. To evaluate the carcass duration time on the lane and its relation to the roadkill time event, we conducted an experiment comparing the removal rate of small carcasses between different stretches of a highway and stretches of dirt roads. The rates found in the study were considered high, with 89 % of carcasses being removed in the first 24 h and 66 % within 12 h. The removals were high for both road categories but reached their peaks at different periods of the day, being higher during the day on the highway and at night on dirt roads. We believe that removal on the highway is dictated by higher vehicular traffic and mainly by the action of scavenger birds during the day, while on dirt roads, it is due to the action of different opportunistic scavengers during the night.     

Synthesis of abnormal immunoglobulins by hybridomas from autoimmune "viable motheaten" mutant mice.

Secretory defects in abnormal plasma cells, called Mott cells, that appear in lymphoid tissues of spontaneously autoimmune, "viable motheaten" (mev/mev) mice lead to deposition of immunoglobulin in RER-bound vesicles. Such vesicles have been termed Russel bodies. Cells with Russel bodies can also be observed rarely in normal animals, usually as a result of extreme antigenic loads or pathologic states. To understand why these abnormal cells appear commonly in mev/mev mice, we have established a panel of hybridomas that contain Russell bodies. Using immunochemical analysis and immunoelectron microscopy, we have characterized the secretory defects. Although these hybridoma cells synthesize a normal size heavy chain and it associates with light chain, the Russell bodies have many characteristics of inclusion bodies, which commonly appear in cells synthesizing mutant proteins and often are associated with incompletely or abnormally folded proteins. Pulse-chase experiments showed that immunoglobulins synthesized by these hybridomas accumulate rapidly into insoluble complexes and have an intracellular half life approximately 10 time greater than normal immunoglobulins. The defect affected only the immunoglobulin derived from the mev/mev mice and did not affect the secretion of normal immunoglobulin produced by an IgG1-secreting fusion partner. In addition to accumulating intracellular immunoglobulins, many mutant cell lines also secreted immunoglobulin. Endoglycosidase H digestion was used to determine the state of processing of the N-linked carbohydrates on the immunoglobulin molecules. This analysis demonstrated that the N-linked carbohydrates on the secreted immunoglobulin were resistant to endoglycosidase H digestion, indicating that they were processed normally. The insoluble IgM molecules were sensitive to endoglycosidase H, which is consistent with their localization to the RER. We propose several models by which these abnormal immunoglobulin-secreting cells commonly appear in this autoimmune mutant mouse.     

An even "newer" animal phylogeny

Metazoa are one of the great monophyletic groups of organisms. They comprise several major groups of organisms readily recognizable based on their anatomy. These major groups include the Bilateria (animals with bilateral symmetry), Cnidaria (jellyfish, corals and other closely related animals), Porifera (sponges), Ctenophores (comb jellies) and a phylum currently made up of a single species, the Placozoa. Attempts to systematize the relationships of these major groups as well as to determine relationships within the groups have been made for nearly two centuries. Many of the attempts have led to frustration, because of a lack of resolution between and within groups. Other attempts have led to "a new animal phylogeny". Now, a study by Dunn et al., using the expresssed sequence tag (EST) approach to obtaining high-throughput large phylogenetic matrices, presents an "even newer" animal phylogeny. There are two major aspects of this study that should be of interest to the general biological community. First, the methods used by the authors to generate their phylogenetic hypotheses call for close examination. Second, the relationships of animal taxa in their resultant trees also prompt further discussion.     

Effect of the substances "Ammivit" and "cerloplasmin" on lipid peroxidation products level and of antioxidant system indicators under irradiation

It has been shown, that the total X-ray irradiation in the dozes of 0.5 and 1 Gy influences on the content of lipid peroxidation products and enzymatic activity of antioxidant system in rat spleen and thymus cells. The influence of preparations "AMMIVIT" and "Ceruloplasmin" on these processes is investigated also. So, the animals feeding by the vitamin concentrate "AMMIVIT" have lead to increase of MDA level (a final product of lipid peroxidation) and the overactivity of some antioxidant enzymes in rat spleen and thymus cells. Injection of the preparation "Ceruloplasmin" to experimental animals up 1 hour before the irradiation has normalized LPO intensity and activity of AO enzymes.     

Effects of sequential pollination on the success of "fast" and "slow" pollen donors in Hibiscus moscheutos (Malvaceae)

Competition among pollen grains for the chance to fertilize ovules typically involves two stages: arrival times on stigmas and/or the growth of pollen tubes through styles. In a previous study of Hibiscus moscheutos, we found that individual pollen donors often differed in pollen tube competitive ability. Here we determined whether short delays in pollen arrival time altered the average success of "fast" and "slow" pollen donors when both types of pollen experienced the same delays. Hand-pollination experiments were carried out using four pairs of pollen donors that differed in competitive ability. We allowed delays of 15 or 30 min between the first and second pollen donor and then determined seed paternity using allozyme markers. The second donor typically sired fewer seeds than pollen that arrived earlier, but, contrary to expectation, "faster" pollen did not always sire significantly more seeds than "slower" pollen when each was applied after delays of the same duration. In two of the four pairs of donors, differences that were seen following simultaneous pollinations disappeared when each type of pollen was applied following identical delays of 15 or 30 min. This unexpected response suggests that the dynamics of pollen tube competition are more complex than anticipated.