Water-borne seed transport and seed deposition during flooding in a small river-valley in Northern Germany

Water-borne seed transport and seed deposition during flooding were studied in the Upper Eider river (N-Germany) by direct sampling of the rivers seed content with aquatic seed traps and by analysing the number of deposited seeds on sedimentation mats which were exposed near the river on the soil surface during a flooding period of approx. three weeks.The number of seeds which were transported at the surface of the river Eider was continuously analysed by four aquatic seed traps for a period of 20 weeks (July–December 2000). To test the capture rate of these traps, a recapture experiment with colour marked seeds of Helianthus annuus L. was carried out. During the investigation period approx. 9000 seeds of 76 species were captured by the four aquatic seed traps. The number of trapped seeds varied both spatially (across the river profile) and temporally. Considering this variation and the capture rate of the traps, the water-borne seed transport was estimated to be 3139 seeds per week and meter of the river profile.The seed deposition during a flood in early spring 2002 was analysed by using 20 sedimentation mats. To distinguish effects of seed dispersal into patches from outside from seed rearrangement within patches, the water-borne seed transport was excluded from one half of the mats by fencing them with a woven fabric which was permeable for water but not for floating seeds. Outside of the exclosures 152 viable seeds of 26 species were deposited on the sedimentation mats while only one single seedling was found on mats from which water-borne seed transport was excluded.The results demonstrate that hydrochorous dispersal processes might play an important role in connecting otherwise fragmented populations in periodically flooded habitats along rivers.     

Forest classification in an Amazonian rainforest landscape using pteridophytes as indicator species

Habitat classification systems are poorly developed for tropical rainforests, where extremely high plant species richness causes numerous methodological difficulties. We used an indicator species approach to classify primary rainforest vegetation for purposes of comparative wildlife habitat studies. We documented species composition of pteridophytes (ferns and fern allies) in 635 plots (2×100 m) along 8 transects within a continuous rainforest landscape in northeastern Peruvian Amazonia. Considerable floristic variation was found when the data were analyzed using multivariate methods. The obtained forest classification was interpreted with the help of indicator value analysis and known soil preferences of the pteridophyte species. The final classification included four forest types: 1) inundated forests, 2) terrace forests, 3) intermediate tierra firme forests and 4) Pebas Formation forests. This rapid and relatively simple vegetation classification technique offers a practical, quantitative method for large-scale vegetation inventory in complex rainforest landscapes.     

Metabolite profiles of Stachybotrys isolates from water-damaged buildings and their induction of inflammatory mediators and cytotoxicity in macrophages

The metabolite profiles of 20 Stachybotrys spp.isolates from Finnish water-damaged buildings were compared with their biological activities. Effects of purified compounds on cytotoxicity and production of inflammatory mediators such as nitric oxide, IL-6 and TNFα in murine RAW264.7 macrophage cells were studied. The 11isolates belonging to the satratoxin-producing chemotype were highly cytotoxic to the macrophages. The isolates inducing inflammatory mediators all belonged to the atranone-producing chemotype, but pure atranones B, and D did not elicit a response in the bioassay. Altogether, cytotoxicity ofStachybotrys sp. isolates appear to be related to satratoxin production whereas the specific component inducing inflammatory responses in atranone-producing isolates remains obscure. This revised version was published online in June 2006 with corrections to the Cover Date.     

Adaptation to fluctuations in temperature by nine species of bacteria

Rapid environmental fluctuations are ubiquitous in the wild, yet majority of experimental studies mostly consider effects of slow fluctuations on organism. To test the evolutionary consequences of fast fluctuations, we conducted nine independent experimental evolution experiments with bacteria. Experimental conditions were same for all species, and we allowed them to evolve either in fluctuating temperature alternating rapidly between 20°C and 40°C or at constant 30°C temperature. After experimental evolution, we tested the performance of the clones in both rapid fluctuation and in constant environments (20°C, 30°C and 40°C). Results from experiments on these nine species were combined meta‐analytically. We found that overall the clones evolved in the fluctuating environment had evolved better efficiency in tolerating fluctuations (i.e., they had higher yield in fluctuating conditions) than the clones evolved in the constant environment. However, we did not find any evidence that fluctuation‐adapted clones would have evolved better tolerance to any measured constant environments (20°C, 30°C, and 40°C). Our results back up recent empirical findings reporting that it is hard to predict adaptations to fast fluctuations using tolerance curves.     

Objective working hour characteristics and work–life conflict among hospital employees in the Finnish public sector study

This epidemiological cohort study, based on Finnish public sector data, investigated the associations between objective working hour characteristics and work–life conflict in day and shift work. The comprehensive data of hospital workers (n = 8 931, 92% women, average age 45 years), consisted of survey responses from 2012, linked with the payroll data of working hour characteristics from 91 days preceding the survey. Logistic regression analysis was used to investigate the associations between working hour characteristics and experiencing work–life conflict often/very often. The analyses were adjusted for age (< 39, 40–49 and >50 years), sex, level of education, marital status, number of small (0–6 years) and school-aged (7–18 years) children, and the overall stressfulness of the life situation. We also conducted stratified analyses of age and sex on the basis of significant interactions. Difficulties in combining work and life were more often associated with shift work without night shifts and shift work with night shifts than with day work (41% and 34 versus 27%; OR for shift work with night shifts 1.78, 95% CI 1.59–2.00, OR for shift work without night shifts 1.42, 95% CI 1.26–1.60). A high proportion (> 25%) of long (> 40h, (OR 1.26, 95% 1.14–1.39) and very long (> 48h, OR 1.31, 95% CI 1.15–1.49) weekly working hours were associated with work–life conflict, and in the stratified analysis, the latter was also true among women (OR 1.54, 95% CI 1.25–1.89). Of the unsocial working hour characteristics, a relatively large amount (> 10% of all shifts) of evening (OR 1.56, 95% CI 1.41–1.72) and night shifts (OR 1.46, 95%CI 1.32–1.61), a high proportion (> 25% of all shifts) of quick returns (< 11h) (OR 1.46, 95% CI 1.31–1.63), and weekend work (OR 1.44, 95% CI 1.31–1.58) were associated with work–life conflict. A large amount of single days off (> 25% of all days off) was associated with work–life conflict among men (OR 1.90, 95% CI 1.11–3.25), but not in the whole sample. When the two types of shift work were analyzed separately, shift work without night shifts and very long work weeks had higher odds (OR 1.47, 95% CI 1.20–1.80) of work–life conflict than shift work with night shifts. Conversely, weekend work and evening shifts had higher odds of work–life conflict among shift workers with night shifts (OR 1.74, 95% 1.55–1.96; (OR 1.57, 95% CI 1.40–1.77) than among those without night shifts. To conclude, this study shows that shift workers with and without night shifts more often have difficulties combining work and life than day workers. Several unsocial working hour characteristics, including long work weeks, evening and night shifts, weekend work, and quick returns, are associated with work–life conflict.     

Synthesis and SAR of novel 1,1-dialkyl-2(1H)-naphthalenones as potent HCV polymerase inhibitors

A series of gem-dialkyl naphthalenone derivatives with varied alkyl substitutions were synthesized and evaluated according to their structure-activity relationship. This investigation led to the discovery of potent inhibitors of the hepatitis C virus at low nanomolar concentrations in both enzymatic and cell-based HCV genotype 1a assays.     

Autocommunication and Perceptual Markers in Landscape: Japanese Examples

Juri Lotman distinguishes between two main types of communication. In addition to the classical I-YOU communication, he speaks about I-I communication, where both the addresser and the addressee are one and the same person. Contrary to how it sounds, autocommunication is not self-sufficient musing inside one’s self, it is remodelling oneself through a code from an entity outside oneself, be it animate or inanimate. According to Lotman, it is often the rhythmical phenomena like poetry, the rhythm of waves, etc. that lend themselves for the act of autocommunication as external codes. After having received the message one is not identical to the original oneself anymore. Perceptual markers of landscape—specific rhythms, ephemera, the rhythm of human everyday activities, bodily movement—can be considered as a secondary code leading to autocommunication in the person who contemplates the landscape. Looking at the landscape—which also implies the rhythmical movement of the eyes—one uses it as a code to reconstitute oneself. A person who has confronted a landscape does not leave it as the same person. The present article poses a definition of autocommunication in landscapes and discusses the way in which other sensorial information apart from the visual—smell, movement, rhythms etc—are used culturally to reinforce autocommunication with oneself. It can be said that several institutionalised religious and cultural practices expect the subject to reconstitute him- or herself mainly through the bodily landscape experience.     

Cryptic gametic interactions confer both conspecific and heterospecific advantages in the Chrysochus (Coleoptera: Chrysomelidae) hybrid zone

Most species pairs are isolated through the collective action of a suite of barriers. Recent work has shown that cryptic barriers such as conspecific sperm precedence can be quite strong, suggesting that they evolve quickly. However, because the strength of multiple barriers has been formally quantified in very few systems, the relative speed with which conspecific sperm precedence evolves remains unclear. Here, we measure the strength of both conspecific sperm precedence and cryptic non-competitive isolation between the hybridizing sister species, Chrysochus auratus and C. cobaltinus (Coleoptera: Chrysomelidae), and compare the strength of those barriers to the strength of other known reproductive barriers in this system. Overall, cryptic barriers in this system are weaker than other barriers, indicating that they have not evolved rapidly. Furthermore, their evolution has been asymmetric. Non-competitive barriers substantially reduce the production of hybrid offspring by C. auratus females but not by C. cobaltinus females. In multiply-mated C. cobaltinus females, heterospecific sperm outcompete conspecific sperm, as evidenced by the fact that heterospecific males sired disproportionately more offspring than predicted from the results for singly-mated females. In C. auratus females, neither sperm type has a competitive advantage. Such asymmetries explain why nearly all F1 hybrids in the field are from crosses between C. cobaltinus females and C. auratus males. We discuss these findings in terms of understanding the cost of mating 'mistakes' in the Chrysochus hybrid zone. In addition, our discovery that 95% confidence intervals for commonly-used isolation statistics can be very wide has important implications for speciation research. Specifically, to avoid biases in the interpretation of such isolation metrics, we suggest that studies should routinely include error estimates in their analyses of reproductive isolation.     

Shunt in the diagnosis of initial lung lesion in smokers

Cigarette smoking is an important risk factor for all respiratory tract diseases. Unfortunately, the symptoms develop slowly, thus patients feel the consequences of the slowly developing inflammation too late. The inflammation first develops in the area of respiratory bronchioles. In this stage, the disease is asymptomatic. The study included a sample of 31 smokers, mean age 36.38 years, with normal spirometry indices, acid-base status and arterial blood gases. The mean smoking index was 11.28 smoking/years. All subjects were healthy, without any subjective health problems or disease indicators. The aim was to define dead lung area (V/Q) as an early indicator of changes in smokers. Study results demonstrated the mean shunt value in smokers of 8.25%, which showed positive correlation with smoking. The shunt size yielded negative correlation with the forced expiratory volume in one second and midexpiratory flow in smokers. In conclusion, determination of lung shunt is a simple method that is sensitive enough in the diagnosis of initial lung lesion due to cigarette smoking.