Long distance pollen transport cause problems for determining the timing of birch pollen season in Fennoscandia by using phenological observations

The male flowering and leaf bud burst of birch take place almost simultaneously, suggesting that the observations of leaf bud burst could be used to determine the timing of birch pollen release. However, long‐distance transport of birch pollen before the onset of local flowering may complicate the utilization of phenological observations in pollen forecasting.

We compared the timing of leaf bud burst of silver birch with the timing of the stages of birch pollen season during an eight year period (1997–2004) at five sites in Finland. The stages of the birch pollen season were defined using four different thresholds: 1) the first date of the earliest three‐day period with airborne birch pollen counts exceeding 10 grains m^?3 air; and the dates when the accumulated pollen sum reaches 2) 5%; 3) 50% and 4) 95% of the annual total. Atmospheric modelling was used to determine the source areas for the observed long‐distance transported pollen, and the exploitability of phenological observations in pollen forecasting was evaluated.

Pair‐wise comparisons of means indicate that the timing of leaf bud burst fell closest to the date when the accumulated pollen sum reached 5% of the annual total, and did not differ significantly from it at any site (p<0.05; Student‐Newman‐Keuls test). It was found that the timing of leaf bud burst of silver birch overlaps with the first half of the main birch pollen season. However, phenological observations alone do not suffice to determine the timing of the main birch pollen season because of long‐distance transport of birch pollen.     

Change of pupal size of Panolis flammea (Lepidoptera; Noctuidae) and Bupalus piniarius (Geometridae) in response to concentration of industrial pollutants in their food plant

Summary Larvae of Panolis flammea and Bupalus piniarius were reared in the laboratory on needles of Scots pine affected by industrial air pollutants in Finland. Needles were collected at different distances from a distinctive source of emission along two 9-km-long transects, and from independent control plots. The elemental composition of the needles used as larval food was analysed. Pupal weight, length and width were negatively correlated wiht the distance from the source of emission. The elemental composition of the pine needles explained 24–53% of the variation in pupal weight. Most of the explained variation was assoicated with the concentration of heavy meals in the pine needles.     

Elasmobranch qPCR reference genes: a case study of hypoxia preconditioned epaulette sharks

Background  

Elasmobranch fishes are an ancient group of vertebrates which have high potential as model species for research into evolutionary physiology and genomics. However, no comparative studies have established suitable reference genes for quantitative PCR (qPCR) in elasmobranchs for any physiological conditions. Oxygen availability has been a major force shaping the physiological evolution of vertebrates, especially fishes. Here we examined the suitability of 9 reference candidates from various functional categories after a single hypoxic insult or after hypoxia preconditioning in epaulette shark (Hemiscyllium ocellatum).     

Early-onset renal cell carcinoma as a novel extraparaganglial component of SDHB-associated heritable paraganglioma

Hereditary paraganglioma syndrome has recently been shown to be caused by germline heterozygous mutations in three (SDHB, SDHC, and SDHD) of the four genes that encode mitochondrial succinate dehydrogenase. Extraparaganglial component neoplasias have never been previously documented. In a population-based registry of symptomatic presentations of phaeochromocytoma/paraganglioma comprising 352 registrants, among whom 16 unrelated registrants were SDHB mutation positive, one family with germline SDHB mutation c.847-50delTCTC had two members with renal cell carcinoma (RCC), of solid histology, at ages 24 and 26 years. Both also had paraganglioma. A registry of early-onset RCCs revealed a family comprising a son with clear-cell RCC and his mother with a cardiac tumor, both with the germline SDHB R27X mutation. The cardiac tumor proved to be a paraganglioma. All RCCs showed loss of the remaining wild-type allele. Our observations suggest that germline SDHB mutations can predispose to early-onset kidney cancers in addition to paragangliomas and carry implications for medical surveillance.     

How specialized volatiles respond to chronic and short‐term physiological and shock heat stress in Brassica nigra

Brassicales release volatile glucosinolate breakdown products upon tissue mechanical damage, but it is unclear how the release of glucosinolate volatiles responds to abiotic stresses such as heat stress. We used three different heat treatments, simulating different dynamic temperature conditions in the field to gain insight into stress‐dependent changes in volatile blends and photosynthetic characteristics in the annual herb Brassica nigra (L.) Koch. Heat stress was applied by either heating leaves through temperature response curve measurements from 20 to 40 °C (mild stress), exposing plants for 4 h to temperatures 25–44 °C (long‐term stress) or shock‐heating leaves to 45–50 °C. Photosynthetic reduction through temperature response curves was associated with decreased stomatal conductance, while the reduction due to long‐term stress and collapse of photosynthetic activity after heat shock stress were associated with non‐stomatal processes. Mild stress decreased constitutive monoterpene emissions, while long‐term stress and shock stress resulted in emissions of the lipoxygenase pathway and glucosinolate volatiles. Glucosinolate volatile release was more strongly elicited by long‐term stress and lipoxygenase product released by heat shock. These results demonstrate that glucosinolate volatiles constitute a major part of emission blend in heat‐stressed B. nigra plants, especially upon chronic stress that leads to induction responses.     

Volume and pH regulation in agnathan erythrocytes: comparisons between the hagfish,Myxine glutinosa,and the lampreys,Petromyzon marinus and Lampetra fluviatilis

The responses of hagfish (Myxine glutinosa) and lamprey (Lampetra fluviatilis and Petromyzon marinus) erythrocytes to osmotic swelling in hypoosmotic medium and to acid-base disturbances induced by ammonium chloride prepulse were studied. The erythrocytes of hagfish regulated neither cell volume after osmotic swelling nor intracellular pH after acidification. In contrast, the erythrocytes of lamprey lost potassium and chloride after osmotic swelling, whereby their volume recovered. Furthermore, the red cell pH of lamprey recovered from experimental acidification in a nominally bicarbonate-free medium in the presence of sodium, confirming that the pathway involved is sodium/proton exchange.Abbreviation DMO 5,5-dimethyloxazolidine-2,4-dione     

Analysis of the human TrkB gene genomic organization reveals novel TrkB isoforms, unusual gene length, and splicing mechanism.

We determined the gene structure of the human TrkB gene. The gene is unusually large and spans at least 590 kbp. It contains 24 exons. Using alternative promoters, splicing, and polyadenylation sites, the gene can create at least 100 isoforms, that can encode 10 proteins. RT-PCR and Northern blot analysis reveals that only three major protein isoforms are generated by the gene: the full length receptor, an isoform lacking the tyrosine kinase domain, and a novel isoform lacking the tyrosine kinase domain but containing a Shc binding site. This novel isoform, TrkB-T-Shc is generated by the use of a new alternative exon 19. It is expressed only in brain. TrkB-T-Shc protein is located in the plasma membrane. Coimmunoprecipitation experiments show that TrkB-T-Shc is not phosphorylated by the full length receptor, indicating that it could be a negative regulator of TrkB signaling in the brain.     

Maternal Prenatal Positive Affect,Depressive and Anxiety Symptoms and Birth Outcomes: The PREDO Study

Background

We investigated whether maternal prenatal emotions are associated with gestational length and birth weight in the large PREDO Study with multiple measurement points of emotions during gestation.

Methods

Altogether 3376 pregnant women self-assessed their positive affect (PA, Positive and Negative Affect Schedule) and depressive (Center for Epidemiologic Studies Depression Scale, CES-D) and anxiety (Spielberger State Anxiety Scale, STAI) symptoms up to 14 times during gestation. Birth characteristics were derived from the National Birth Register and from medical records.

Results

One standard deviation (SD) unit higher PA during the third pregnancy trimester was associated with a 0.05 SD unit longer gestational length, whereas one SD unit higher CES-D and STAI scores during the third trimester were associated with 0.04–0.05 SD unit shorter gestational lengths (P-values ≤ 0.02), corresponding to only 0.1–0.2% of the variation in gestational length. Higher PA during the third trimester was associated with a significantly decreased risk for preterm (< 37 weeks) delivery (for each SD unit higher positive affect, odds ratio was 0.8-fold (P = 0.02). Mothers with preterm delivery showed a decline in PA and an increase in CES-D and STAI during eight weeks prior to delivery. Post-term birth (≥ 42 weeks), birth weight and fetal growth were not associated with maternal prenatal emotions.

Conclusions

This study with 14 measurements of maternal emotions during pregnancy show modest effects of prenatal emotions during the third pregnancy trimester, particularly in the weeks close to delivery, on gestational length. From the clinical perspective, the effects were negligible. No associations were detected between prenatal emotions and birth weight.