Assessment of Anxiety Level and Mental Health Status in Spouses and Children of Day-Working and Shift-Working Men

The present study was aimed at assessing the effects of the unusual schedules of shift-working men on anxiety and mental health of their spouses and children. The anxiety and mental health of 396 subjects that include 133 spouses and 263 children of day-working and shift-working men were monitored by employing specific inventory. Anxiety scales (trait, state and free-floating) and mental health inventory were administrated to each subject. Results indicate that the average levels of free-floating anxiety for the spouses and children of shift-working men were found to be significantly higher in comparison with that of their counterparts sampled in the family of day workers. This was also true when data were segregated with respect of gender and compared. Except in female children of shift workers all other groups of children had statistically significantly higher level of state anxiety as compared with that of their respective mothers. The results of this study further reveal that the spouses of shift-working men exhibited lower mental health rating as compared with the spouses of day-working men. Furthermore, a significant negative relationship was noticed between anxiety and mental health in all cases excepting in spouses of shift-working men for state anxiety. Although the findings of the present study could be attributed to the irregular routine of shift workers, it appears mandatory to carryout further intensive studies to draw convincing conclusions.     

Intraspecific genetic variation in Paramecium revealed by mitochondrial cytochrome C oxidase I sequences

Studies of intraspecific genetic diversity of ciliates, such as population genetics and biogeography, are particularly hampered by the lack of suitable DNA markers. For example, sequences of the non-coding ribosomal internal transcribed spacer (ITS) regions are often too conserved for intraspecific analyses. We have therefore identified primers for the mitochondrial cytochrome c oxidase I (COI) gene and applied them for intraspecific investigations in Paramecium caudatum and Paramecium multimicronucleatum. Furthermore, we obtained sequences of the ITS regions from the same strains and carried out comparative sequence analyses of both data sets. The mitochondrial sequences revealed substantially higher variation in both Paramecium species, with intraspecific divergences up to 7% in P. caudatum and 9.5% in P. multimicronucleatum. Moreover, an initial survey of the population structure discovered different mitochondrial haplotypes of P. caudatum in one pond, thereby demonstrating the potential of this genetic marker for population genetic analyses. Our primers successfully amplified the COI gene of other Paramecium. This is the first report of intraspecific variation in free-living protozoans based on mitochondrial sequence data. Our results show that the high variation in mitochondrial DNA makes it a suitable marker for intraspecific and population genetic studies.     

Method for the Simultaneous Establishment of Many Axenic Cultures of Paramecium*†

SYNOPSIS. A method is described for the simultaneous treatment of 42 (or more) stocks of Paramecium, and their adaptation to growth in axenic culture. Samples of dense cultures of these ciliates growing with Enterobacter aerogenes are rendered bacteria-free by migration through 2 sets of tubes containing Adaptation Medium (Peters' salts solution, stigmasterol, vitamins, and autoclaved E. aerogenes). The 2nd set of tubes contains Adaptation Medium plus antibiotics. Bacteria-free samples containing ～ 100 animals are then transferred to test tubes containing Adaptation Medium without antibiotics. This medium also serves as a growth medium. It supports indefinite growth of all Paramecium stocks tested. After adaptation to this medium, the ciliates can be grown in the axenic medium developed by Soldo, Godoy & van Wagtendonk. On a single trial at least half of the stocks can be expected to produce axenic cultures within 5 to 10 days by these procedures. The method has been applied successfully to several of the species of the Paramecium aurelia complex, to all syngens of Paramecium multimicronucleatum, to several stocks of Paramecium jenningsi, and to 1 stock each of Paramecium caudatum and Paramecium calkinsi. A modification of the method also works for Didinium nasutum.     

Feeding and Mating Reactivity in Paramecium multimicronucleatum

SYNOPSIS. Paramecium multimicronucleatum produced abnormal (L- and Δ-shaped) cells when cultivated in the presence of 3 mM adenine. These abnormal cells were unable to form food vacuoles in the presence of bacteria in the culture. In bacteria-rich culture, mating reactivity was not expressed in normal Paramecium ; however, it was expressed in the adenine-treated abnormal cells even in the presence of excess bacteria. The expression of mating reactivity in Paramecium was not affected by ingestion of polystyrene latex particles. These results show that the inhibition of mating reactivity in bacterized culture medium is caused by absorption of nutrients from bacteria digested in food vacuoles.     

Effect of Adenine on Paramecium multimicronucleatum*

SYNOPSIS. The addition of adenine to the culture medium of Paramecium multimicronucleatum caused an inhibition of conjugation and fission and also an increase in the number of food vacuoles. The inhibition of conjugation was observed at the stage of adhesion of cell membranes. With adenine, the duration of fission was prolonged and L-shaped cells were formed. Adenine apparently repressed the excretion of food vacuoles and thus caused an accumulation of food vacuoles within the cells. All these effects were observed at similar concentrations of adenine higher than 2 mM. The addition of uridine to the adenine-containing medium reversed the inhibition of fission; conjugation and vacuole accumulation remained unaffected.     

Antibodies Blocking the Mating Reaction In Paramecium Multimicronucleatum Syngen 2

SYNOPSIS Antibodies induced in rabbits against Paramecium multimicronucleatum syngen 2 prevent sexually reactive cells from clumping, pairing, and forming cytoplasmic fusions. A biologic assay for the detection of these antibodies (designated blocking antibodies ) is described. the blocking antibodies, unlike the immobilization antibodies, are produced against breis of sexually reactive cells and nonreactive cells of 2 types, nonstarved and immature. Isolated cilia from reactive cells of either mating type are weak immunogens for blocking antibodies. No correlation between the mating type specificity (III or IV) and these antibodies has been detected. Blocking antibodies can be absorbed with living cells, of which sexually reactive ones are the most effective absorbers, while immature ones are the least effective.     

Relation Between Cell Union and Nuclear Reorganization in Triplet Conjugants of Paramecium caudatum and Paramecium multimicronucleatum

SYNOPSIS Triplet conjugants of Paramecium caudatum which appeared naturally in mating mixtures and those of Paramecium multimicronucleatum which were produced by conjugation-inducing chemicals were isolated. Triplet conjugants lasting for more than 3 h were stained to examine macronuclear events. In P. caudatum , only 2 triplets among 182 (1%) contained macronuclear fragmentation in all 3 members. The most frequently occurring triplets (79%) were those producing 1 cell without and 2 cells with macronuclear fragments. There were also triplets (17%) producing 1 cell with, and 2 without macronuclear fragments, and some (3%) with 3 cells that contained no fragments. The length of persistence of the triplet was not responsible for the occurrence of macronuclear fragmentation in the 3rd cell of the triplet. In P. multimicronucleatum , the same 4 classes of triplets occurred, but the most frequently occurring class was that consisting of 3 cells (91%) with macronuclear fragments. Induction of nearly 100% of triplets with 3 such cells was possible by isolating the triplets' from a culture which was treated chemically at about 24 h after the last feeding. Treatment with chemicals in starved cultures resulted in triplets with incompletely fragmented or nonfragmented macronuclei. Further, in P. multimicronucleatum , chemicallyinduced triplets involving only holdfast pairs to which the 3rd cells were uniting often produced 3 cells with fragmented macronuclei.     

Phosphorus Regeneration in Fresh-Water Paramecia*

Turnover rates of soluble phosphorus (P) by Paramecium multimicronucleatum were compared under 3 temperature regimes. Phosphorus uptake by this heterotroph was almost completely dependent on consumption of bacteria rather than direct uptake of soluble ³²PO₄. Phosphorus uptake rates by P. bursaria when in its autotrophic state (a symbiotic relationship with zoochlorellae) and when in its heterotrophic (bacteria feeding) state were also compared. Paramecium bursaria showed a much higher uptake of P when large numbers of labeled bacteria were present than when they were absent. Phosphorus turnover rates by P. bursaria were determined and compared with those of P. multimicronucleatum. These ciliates showed remarkably rapid turnover rates for soluble P. In each case turnover rates were universely related to biomass. Ciliates, although small, have very high metabolic rates and therefore may be important for nutrient regeneration in our fresh-water lakes, streams, and ponds.     

A new species of Elpidium (Crustacea,Ostracoda) from bromeliads in Cusuco National Park,Honduras

Passively dispersing aquatic invertebrates such as Ostracoda in restricted aquatic habitats such as bromeliads remain an intriguing observation considering the highly specialised dispersal vectors needed for efficient colonisation. Here we describe a new species of Elpidium, Elpidium merendonense sp. n., collected from bromeliads in the cloud forest from Cusuco National Park, Honduras. Elpidium merendonense sp. n. is a small to medium-sized species that can be easily distinguished from its congeners by its unique outgrowth at the posterior end of the left valve, visible especially in females. The species was common all through the park occurring at a wide range of altitudes and in different species of bromeliads. This finding is the first freshwater ostracod species described from Honduras and is in agreement with the prediction that the genus Elpidium contains a large number of species with small geographic distributions. We update the list of described species of Elpidium and present a key to species.     

Cultivation-independent analysis reveals a shift in ciliate 18S rRNA gene diversity in a polycyclic aromatic hydrocarbon-polluted soil

Using cultivation-independent methods the ciliate communities of a clay-rich soil with a 90-year record of pollution by polycyclic aromatic hydrocarbons (PAH) (4.5 g kg(-1) PAH) were compared with that of a nonpolluted soil collected in its vicinity and with similar properties. A ciliate-specific set of 18S rRNA gene targeting primers was designed and used to amplify DNA extracted from both soils (surface and 20 cm depth). Four clone libraries were generated with PCR products that covered an 18S rRNA gene fragment of up to 670 bp. Comparative sequence analysis of representative clones proved that the primer set was highly specific for ciliates. Calculation of similarity indices based on operational taxonomic units after amplified ribosomal DNA restriction analysis of the clones showed that the community from the nonpolluted surface soil was highly dissimilar to the other communities. The presence of several taxa, namely sequences affiliated to the orders Phyllopharyngia, Haptoria, Nassophorea, Peniculida and Scuticociliatia in samples from nonpolluted soil, points to the existence of various trophic functional groups. In contrast, the 18S rRNA gene diversity was much lower in the clone libraries from the polluted soil. More than 90% of these sequences belonged to the class Colpodea, a well-known clade of mainly bacterivorous and r-selected species, thus potentially also indicating a lower functional diversity.     

Reevaluation of the ‘well-known’ Paraurostyla weissei complex,with notes on the ontogenesis of a new Paraurostyla species (Ciliophora,Hypotrichia)

Two hypotrichous ciliates, Paraurostyla wuhanensis nov. spec. from Wuhan (China) and a new North American population of the Paraurostyla weissei complex, were studied based on live observations and protargol impregnation. Paraurostyla wuhanensis nov. spec. differs from the congeners by the combined features of having six or seven frontal cirri, 2–4 frontoventral cirri, 5–7 ventral rows, and yellow-greenish cortical granules. Ontogenesis proceeds as in the type species, except that fewer frontoventral cirri are formed in the new species. The morphology of the new population of the Paraurostyla weissei complex corresponds well with other American populations. In the phylogenetic trees based on the 18S rRNA gene, Paraurostyla sequences nest in a large clade together with Apoamphisiella and Notohymena. Monophyly of Paraurostyla is rejected by the results of the approximately unbiased test analyses. Morphological, morphogenetic, and phylogenetic analyses show a close relationship between the North American populations of the Paraurostyla weissei complex and Apoamphisiella, indicating that the taxonomic position of the former needs to be reassigned. A new combination, viz. Apoamphisiella polymicronucleata (Merriman, 1937) comb. nov., a reevaluation of the Paraurostyla weissei complex, and emended diagnoses of Paraurostyla and Apoamphisiella, are provided.     

An inter‐oscillator mechanism modulating circadian clock period in paramecium populations

Abstract

In populations of the ciliate protozoan, Paramecium multimicronucleatum, the circadian‐clock‐con‐trolled mating reaction expressed by a limited number of cells among them feeds back to contribute to coherence of their circadian rhythms of motility and mating reaction. This eventually causes a decrease in the period of the rhythms from the entrained 24h period to a steady‐state period of about 22h, with the rate of decrease depending on the strength of the mating reaction. These results suggest that the interaction among oscillators may be one of the factors which modulate the period of a circadian clock composed of nearly identical oscillators. The clock‐controlled mating reaction provides a promising inter‐oscillator pathway for obtaining more insight into the mechanism of modulation of the period of such circadian clocks through inter‐oscillator interaction.