Paleolimnological reflections of fiber-plant retting in the sediment of a small clear-water lake

Likolampi is a small groundwater kettle-hole lake in Ilomantsi, Eastern Finland. At 11 m water depth the uppermost 51 cm of sediment contains about 390 varves. A thin layer of chrysophyte statospores is the main structural unit in these; in some varves it is followed by a layer of cf. Drepanocladus fluitans moss spores. Below the laminated sequence, two layers of moss detritus (110–87 cm, 81–51 cm) alternate with greyish brown fine detritus. Pollen analysis reveals that the start of the deposition of varved sediment coincides with the beginning of intensive fiber plant retting with large quantities of Cannabis/Humulus -type pollen and even regular occurrence of the insect-pollinated Linum usitatissimum. The cf. Drepanocladus spores are almost absent during the retting period (c. 1590–1900 by the varves), but very common before and after it. Drepanocladus fluitans is capable of assimilating dissolved CO₂ in water, so it thrives at low pH and is typical for oligotrophic clear-water lakes. We conclude that the stratigraphy of Drepanocladus fragments and spores is a true negative indicator of cultural influence in Likolampi.     

Subcellular and Perisynaptic Distribution of Rat Brain Aldehyde Dehydrogenase Activity

Abstract: The nuclear mitochondrial and synaptosomal fractions of rat brain were each found to contain some 25–30% of the total aldehyde dehydrogenase activity. The cytoplasmic fraction had a very low total aldehyde dehydrogenase activity. There were differences in the distribution of the activity when different aldehydes were used as substrates, suggesting the presence of isoenzymes in the various subcellular compartments. When rats were treated intra-cisternally with 6-hydroxydopamine there was no change in brain aldehyde dehydrogenase activity, although the noradrenaline content and the activities of tyrosine hydroxylase and dopamine-β-hydroxylase were markedly decreased. Treatment with 6-hydroxydopamine also had no significant effect on the aldehyde dehydrogenase activity in retinal homogenates. The results suggest that the aldehyde dehydrogenase activity in rat brain is predominantly outside the catecholaminergic nerve terminals.     

Yeasts isolated from industrial maltings can suppress <Emphasis Type="Italic">Fusarium</Emphasis> growth and formation of gushing factors

Fusarium infection of barley and malt can cause severe problems in the malting and brewing industry. In addition to being potential mycotoxin producers, Fusarium fungi are known to cause beer gushing (spontaneous overfoaming of beer). Cereal-derived bacteria and yeasts are potential biocontrol agents. In this study, the antifungal potential of selected yeasts (12 strains) derived from the industrial malting ecosystem was studied in vitro with a plate-screening assay. Several ascomycetous yeast strains showed antagonistic activity against field and storage moulds, Pichia anomala being the most effective strain. The effects of P. anomala VTT C-04565 (C565) were examined in laboratory scale malting with naturally contaminated barley exhibiting gushing potential. P. anomala C565 restricted Fusarium growth and hydrophobin production during malting and prevented beer gushing. Grain germination was not disturbed by the presence of yeast. Addition of P. anomala C565 into the steeping seemed to retard wort filtration, but the filtration performance was recovered when yeast culture was combined with Lactobacillus plantarum VTT E-78076. Well-characterized microbial cultures could be used as food-grade biocontrol agents and they offer a natural tool for tailoring of malt properties.     

Membrane interaction and disulphide-bridge formation in the unconventional secretion of Tau

Misfolded, pathological tau protein propagates from cell to cell causing neuronal degeneration in Alzheimer’s disease and other tauopathies. The molecular mechanisms of this process have remained elusive. Unconventional secretion of tau takes place via several different routes, including direct penetration through the plasma membrane. Here, we show that tau secretion requires membrane interaction via disulphide bridge formation. Mutating residues that reduce tau interaction with membranes or formation of disulphide bridges decrease both tau secretion from cells, and penetration through artificial lipid membranes. Our results demonstrate that tau is indeed able to penetrate protein-free membranes in a process independent of active cellular processes and that both membrane interaction and disulphide bridge formation are needed for this process. QUARK-based de novo modelling of the second and third microtubule-binding repeat domains (MTBDs), in which the two cysteine residues of 4R isoforms of tau are located, supports the concept that this region of tau could form transient amphipathic helices for membrane interaction.     

Do warmer growing seasons ameliorate the recovery of mountain birches after winter moth outbreak?

Subarctic mountain birch (Betula pubescens ssp. czerepanovii) forests in northern Fennoscandia have shown a slight recovery from recent severe defoliation by the winter moth (Operophtera brumata). This development in trees is hypothesized to be a result of ameliorated growing conditions through increased summer temperatures. We examined if accumulated thermal sum affects the ability of mountain birches to tolerate foliage losses. We quantified the number of leaf-bearing short shoots, the emergence of inflorescences and the seasonal height growth of long shoots in both intact and defoliated trees. We also determined the concentrations of carbon and nitrogen in leaves and carbohydrates in roots. Our results show that defoliation constrained the growth of long shoots, as well as the emergence of inflorescences regardless of thermal sum accumulation. However, the number of leaf-bearing short shoots did not differ between intact and defoliated trees. In the both tree groups, the amounts of emerging leaves increased as a response to thermal sum accumulation. Also the leaf carbon concentration increased in defoliated trees at higher thermal sums, whereas it decreased in intact controls. Generally, the mean carbohydrate concentrations were greater in roots of defoliated than intact trees. However, with increased thermal sums, root carbohydrates increased in intact trees but remained the same in defoliated trees. We conclude that thermal sum accumulation does not greatly promote the recovery of mountain birches. Although the damaged trees produced more leaves at warmer growing sites, this did not increase their height growth or carbohydrate gain in roots.     

Hormonal responses to a resistance exercise performed under the influence of delayed onset muscle soreness

Hormonal responses to an unaccustomed knee-extension exercise (E1; 5 times 10 repetitions with 40% load of 1RM [1 repetition maximum] followed by 2 sets until exhaustion) were compared in 6 men with the corresponding responses to an identical exercise performed 2 days later under the influence of delayed onset muscle soreness (DOMS) (E2). Both exercises were performed with a variable-resistance machine causing exhaustion with significantly fewer repetitions than a normal constant-resistance knee-extension device does. The E1 induced DOMS as expected, but the 1RM, the total work done, and the repetition number and frequency were not different in the 2 exercises. In the 2 sets to failure, the mean repetition number varied between 17 and 25. The exercise-induced norepinephrine, epinephrine, testosterone, cortisol (COR), and growth hormone (GH) increases were similar in the 2 exercises, although the overall level of COR and GH, including the preexercise concentrations, tended to decline in the second exercise. The results may thus suggest that the hormonal response to resistance exercise is not significantly altered when performed soon after an unaccustomed exercise bout leading to DOMS.     

Gestational exposure to cigarette smoke imperils the long-term physical and mental health of offspring

BACKGROUND: In this study, we sought to understand whether prenatal exposure to cigarette smoke would be associated with increased offspring hospitalization through age 22 years for various physical and mental health diagnoses. METHODS: We used multivariate logistic regression to investigate the relationship between gestational exposure to cigarette smoke and offspring hospitalization for physical and mental health conditions based on International Classification of Diseases (ICD; World Health Organization) diagnoses. RESULTS: When controlling for parental psychiatric status, maternal somatic health, socioeconomic status, parity, and maternal age, youth born to mothers who smoked six or more cigarettes per day were more likely to have experienced hospitalization for neuroses (OR, 1.97), diseases of the nervous system (i.e., neurological disorders) (OR, 1.47), respiratory infections (OR, 1.28), accidents (OR, 1.44), infections (OR, 1.54), undiagnosed symptoms (OR, 1.65), and total admissions (OR, 1.48). Female offspring prenatally exposed were more likely to have experienced hospitalization for obstetric complications (OR, 2.94). No association was found for the remaining categories analyzed: blood disorders, skin diseases, psychoses, metabolic/endocrine disease, circulatory disease, digestive disease, disease of the skeletal/muscular system, physical anomalies, neoplasms, and genital/urinary disease. CONCLUSIONS: This is the first study to investigate the impact of gestational exposure to cigarette smoke on global measures of somatic and physical health in offspring. This study adds to the literature by demonstrating that smoking during pregnancy increases offspring risk for additional health outcomes not previously recognized in the literature, and that the effect of smoking during pregnancy persists throughout the developmental period. The possibility that these findings are related to lifestyle markers or smoke exposure during childhood should also be considered.     

Cyclic nucleotide phosphodiesterases (PDEs) in human osteoblastic cells; the effect of PDE inhibition on cAMP accumulation

The regulation of the secondary messengers, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), is crucial in the hormonal regulation of bone metabolism. Both cAMP and cGMP are inactivated by cyclic nucleotide phosphodiesterases (PDEs), a superfamily of enzymes divided into 11 families (PDE1-11). We compared the PDEs of cultured human osteoblasts (NHOst) and SaOS-2 osteosarcoma cells. The PDE activity of NHOst cells consisted of PDE1, PDE3 and PDE7, whereas PDE1, PDE7 and PDE4, but no PDE3 activity was detected in SaOS-2 cells. In line with the difference in the PDE profiles, rolipram, a PDE4 inhibitor, increased the accumulation of cAMP in SaOS-2, but not in NHOst cells. Expression of PDE subtypes PDE1C, PDE3A, PDE4A, PDE4B, PDE7A and PDE7B was detected in both cell types. NHOst cells additionally expressed PDE1A.     

Robust detection of periodic time series measured from biological systems

Background  

Periodic phenomena are widespread in biology. The problem of finding periodicity in biological time series can be viewed as a multiple hypothesis testing of the spectral content of a given time series. The exact noise characteristics are unknown in many bioinformatics applications. Furthermore, the observed time series can exhibit other non-idealities, such as outliers, short length and distortion from the original wave form. Hence, the computational methods should preferably be robust against such anomalies in the data.