Defect reconstruction in a two-dimensional semi-analytical waveguide model via derivative-based optimization

This paper considers an indirect measurement approach to reconstruct a defect in a two-dimensional waveguide model for a non-destructive ultrasonic inspection via derivative-based optimization. The propagation of the mechanical waves is simulated by the scaled boundary finite element method that builds on a semi-analytical approach. The simulated data are then fitted to given data associated with the reflected waves from a defect which is to be reconstructed. For this purpose, we apply an iteratively regularized Gauss-Newton method in combination with algorithmic differentiation to provide the required derivative information accurately and efficiently. We present numerical results for three kinds of defects, namely, a crack, delamination, and corrosion. The objective function and the properties of the reconstruction method are investigated. The examples show that the parameterization of the defect can be reconstructed efficiently as well as robustly in the presence of noise.

Depressive symptoms are not associated with long-term integrated testosterone concentrations in hair

OBJECTIVES

The association between depressive symptomatology and endogenous testosterone levels is inconclusive. Large inter- and intra-individual testosterone differences suggest point measurements from saliva or serum to be inadequate to map basal testosterone concentrations highlighting the potential for long-term integrated testosterone levels from hair.

METHODS

Using data from a prospective cohort study, a total of 578 participants (74% female) provided complete data on depressive symptomatology, clinical features, and hair samples for quantification of testosterone concentrations at baseline. Available data of three annual follow-up examinations were used for longitudinal analyses.

RESULTS

Correlation analysis showed in both, men and women, hair testosterone across all the four time points not to be significantly related to depressive symptoms. Examined clinical features were not associated with testosterone levels, except for having a current diagnosis of a psychological disorder, which was associated with reduced testosterone levels in men, but not in women. Acceptable model fit for an autoregressive cross-lagged panel analysis emerged only for the female subsample suggesting inverse cross-relations for the prediction of testosterone by depressive symptomatology and vice versa.

CONCLUSIONS

Findings from this study add to the literature by showing no association between long-term integrated testosterone in hair and depressive symptomatology in men and women.

Age-Related Alterations in Endocrine Markers Do Not Match Changes in Psychosocial Measures: Findings From the Men's Health 40+ Longitudinal Study

While life expectancy continues to increase, aging can bring several distinct endocrine and psychosocial changes. The study aimed to investigate the interplay between biopsychosocial factors of healthy aging in specifically healthy aging men. Ninety-seven healthy aging men were investigated at two time points spanning 4 years. Participants completed questionnaires measuring several psychosocial dimensions and gave saliva samples for hormone quantification during a laboratory appointment. The study applied a random intercept mixed-model approach. Age-related changes were found in most endocrine markers (cortisol, testosterone, dehydroepiandrosterone-sulfate, and progesterone), except for estradiol. Psychosocial measures remained stable, except for increased social support. Further, changes in endocrine and psychosocial measures were independent of each other. The results suggest that in healthy aging men, age-related endocrine changes occur, but do not necessarily determine a change in psychosocial measures. Potentially, preventive interventions can be derived from these results.

Do dehydroepiandrosterone, progesterone, and testosterone influence women's depression and anxiety levels? Evidence from hair-based hormonal measures of 2105 rural Indian women

Depressive and anxiety disorders substantially contribute to the global burden of disease, particularly in poor countries. Higher prevalence rates for both disorders among women indicate sex hormones may be integrated in the pathophysiology of these disorders. The Kshetriya Gramin Financial Services study surveyed a random sample of 4160 households across 876 villages in rural Tamil Nadu, India. An interviewer-administered questionnaire was conducted to quantify depressive (K6-D) and anxiety (K6-A) symptoms. Alongside, hair samples for sex hormone profiling were collected from a subsample of 2105 women aged 18-85 years. Importantly, 5.9%, 14.8%, and 46.3% of samples contained non-detectable hormone levels for dehydroepiandrosterone, progesterone, and testosterone, respectively. Our primary analysis imputes values for the non-detectable sample and we check robustness of results when non-detectable values are dropped. In this cohort of women from rural India, higher depressive symptomatology is associated with lower levels of dehydroepiandrosterone and higher depressive and anxiety symptoms are associated with higher levels of testosterone. Progesterone shows no clear association with either depressive or anxiety symptoms. These results support a potential protective effect of higher endogenous dehydroepiandrosterone levels. An important caveat on the potential negative effect of hair testosterone levels on women's mental health is that the testosterone analysis is sensitive to how non-detectable values are treated.

Higher testosterone levels are associated with unfaithful behavior in men

BACKGROUND

Infidelity in romantic relationships is a common, but severe issue often causing breakup and severe psychological impairment. Higher levels of testosterone are related to mating-behavior, sexual desire, and infidelity in men with sexual dysfunctions. Previous studies, have insufficiently addressed the potential role of testosterone in infidelity in healthy men.

METHODS

A sample of 224 middle-aged self-reporting healthy men being currently in a relationship completed questionnaires on relationship characteristics, infidelity, and provided overnight-fasting saliva samples for testosterone quantification.

RESULTS

In the sample, 37.5% men answered having been unfaithful in the current relationship, while 29% were identified as fulfilling criteria for a sexual dysfunction. Adjusting for covariates, a significant positive association for the frequency of unfaithful behavior and testosterone levels emerged. Subsample analysis indicates a positive association between testosterone and infidelity only to be present in men without sexual dysfunction.

CONCLUSION

Unfaithful behavior in males is associated with higher testosterone levels.

Correction: Safety and utility of image-guided research biopsies in relapsed high-grade serous ovarian carcinoma-experience of the BriTROC consortium

This article was originally published under a CC BY NC SA License, but has now been made available under a CC BY 4.0 License.

Associations between digit ratio (2D4D), mood, and autonomic stress response in healthy men

The ratio between the length of the second (index) and the fourth (ring) finger (2D4D) is a putative biomarker of prenatal testosterone (T) exposure, with higher exposure leading to a smaller ratio. 2D4D has further been linked to mental and somatic disorders. Healthy male Swiss recruits (N = 245; M_age = 20.30 years) underwent a psychosocial stress test. Mood and salivary alpha-amylase (sAA) were assessed before and after the stress test, while heart rate (HR) and heart rate variability (HRV) were measured continuously. Additionally, 2D4D (right: R2D4D; left: L2D4D) was determined and divided into quartile groups. Correlation analysis showed no associations between R/L2D4D and outcome measures. Comparing calculated quartiles for R2D4D, subjects in the lowest R2D4D quartile expressed trendwise (p < 0.10) lower positive and higher negative affect, significantly elevated sAA activity (p < 0.05), but no HR and HRV differences at baseline as compared to subjects in the upper three quartiles. With regard to acute stress, subjects in the lowest as compared to subjects in the upper three R2D4D quartiles showed a higher increase of negative affect and a stronger cardiac response (p < 0.05), but no alterations in positive affect and sAA activity. Young healthy men in the lowest R2D4D quartile revealed a more negative affect and increased physiological activity at baseline and in response to acute stress. An exposure to high levels of prenatal T might constitute a risk factor potentially increasing vulnerability to stress-related disorders in men.

Lower birthweight and left-/mixed-handedness are associated with intensified age-related sex steroid decline in men. Findings from the Men's Health 40+ Study

In males, age‐related decline in free testosterone (T) and dehydroepiandrosterone (DHEA) by 2–3% per year has been reported. Estradiol (E2) and progesterone (P) seem to decrease as well, but to a lesser extent. Lower sex steroid levels in men have been related to physical and mental symptoms. Low birthweight and left‐/mixed‐handedness (L/MH) are indicators of an adverse fetal environment during pregnancy, and both have been linked to morbidity in later life. The aim of this study is to examine the relationship between lower birthweight as well as L/MH and age‐related sex steroid decline. In a cross‐sectional study design, saliva samples were collected under standardized conditions from healthy men for subsequent steroid hormone analysis using standard luminescence immunoassays. T (M = 67.57 pg/mL), DHEA (M = 247.91 pg/mL), E2 (M = 1.29 pg/mL), and P (M = 28.20 pg/mL) have been quantified leading to a final sample of 256 men providing complete data on sex hormones (M_Age=57.8; SD_Age = 10.8). Information on participants’ birthweight was obtained from birth reports (N = 134), and participants were asked about their handedness (right‐handed, left‐handed, mixed‐handed) (N = 256). Multivariate‐adjusted linear regression models relating each sex hormone individually and the principal component of declining steroid hormones (DSH)—an integrated hormonal parameter—with handedness and birthweight did not identify significant associations except for handedness and E2. Moderation analysis using robust regression accounting for bias due to influential data points detected a significant association between age and DSH for handedness (β = −0.0314, p = 0.040) but only a trend for birthweight (β = 0.0309, p = 0.073). For lower birthweight, a trend toward intensified age‐related sex steroid decline in men was observed, while for L/MH, a significant association with intensified age‐related sex steroid decline was identified. These results indicate that L/MH and potentially also lower birthweight might be considered as early risk factors for endocrine health in later life.

Safety and utility of image-guided research biopsies in relapsed high-grade serous ovarian carcinoma-experience of the BriTROC consortium

BACKGROUND

Investigating tumour evolution and acquired chemotherapy resistance requires analysis of sequential tumour material. We describe the feasibility of obtaining research biopsies in women with relapsed ovarian high-grade serous carcinoma (HGSC).

METHODS

Women with relapsed ovarian HGSC underwent either image-guided biopsy or intra-operative biopsy during secondary debulking, and samples were fixed in methanol-based fixative. Tagged-amplicon sequencing was performed on biopsy DNA.

RESULTS

We screened 519 patients in order to enrol 220. Two hundred and two patients underwent successful biopsy, 118 of which were image-guided. There were 22 study-related adverse events (AE) in the image-guided biopsies, all grades 1 and 2; pain was the commonest AE. There were pre-specified significant AE in 3/118 biopsies (2.5%). 87% biopsies were fit-for-purpose for genomic analyses. Median DNA yield was 2.87 μg, and was higher in biopsies utilising 14 G or 16 G needles compared to 18 G. TP53 mutations were identified in 94.4% patients.

CONCLUSIONS

Obtaining tumour biopsies for research in relapsed HGSC is safe and feasible. Adverse events are rare. The large majority of biopsies yield sufficient DNA for genomic analyses-we recommend use of larger gauge needles and methanol fixation for such biopsies, as DNA yields are higher but with no increase in AEs.

Temporal control of i-motif switch lifetimes for autonomous operation of transient DNA nanostructures

System integration of the DNA i-motif switch with a tunable pH environment allows programmable lifetimes of DNA duplex hybridization and higher level self-assemblies in closed and autonomous systems.

Functional DNA nanotechnology creates increasingly complex behaviors useful for sensing, actuation or computation, as enabled via the integration of dynamic and responsive structural DNA motifs. However, temporally controlled and dynamic DNA structures with programmable lifetimes, that are able to operate autonomously and self-revert to the starting state are challenging to achieve due to tedious and very system-specific sequence design. Here, we present a straightforward concept to program transient lifetimes into DNA duplexes based on the pH-sensitive DNA i-motif switch. We integrate the i-motif switch with an internal, non-linear pH-resetting function using a rationally designed chemical reaction framework, by which the switch autonomously undergoes a complete “off–on–off”-cycle without the use of additional external triggers. The lifetime of the activated “on”-state (i.e. the hybridized state) can be systematically programmed over several hours. The system can be readily implemented into hybrid DNA structures on larger length scales. Focusing on autonomous materials, we demonstrate temporal control of transient fluorescence signals and temporary aggregation of gold nanoparticles.

[Position Paper: Perioperative Management of Adult Patients with Obstructive Sleep Apnea in ENT Surgery]

Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder with an increasing prevalence. Affected individuals suffer from a repetitive partial or complete occlusion of the pharyngeal airway despite continued respiratory efforts leading to sleep fragmentation, abnormal gas exchange and significant cardiovascular and metabolic morbidity. Surgical patients with OSA, which in the majority of cases has not been diagnosed prior to surgery, have an increased risk of developing a variety of pulmonary, cardiovascular and other complications throughout the perioperative period. Certain actions may contribute to increase the safety of patients with OSA during this time. Among them are preoperatively, a timely recognition and assessment of OSA and potentially co-existing diseases, intraoperatively, the selection of an appropriate anaesthesia and monitoring technique, and postoperatively, the continuation of monitoring for an adequate period of time with the option of intensive care treatment. The actual clinical approach should follow the risk profile of the individual patient which is determined by OSA severity, invasiveness of the surgical procedure and requirement for postoperative opioids as well as the incidence of critical events in the early postoperative period. Initiated and mandated by the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery, and conceived on the basis of the available literature and existing guidelines, the following paper provides recommendations for the perioperative management of adult patients with OSA in ENT surgery.

Blending of reactive prepolymers to control the morphology and polarity of polyglycidol based microgels

The compartmentalization of microgels is a challenging task for synthetic polymer chemistry. Although the complexation with low molecular weight compounds or the use of microfluidic techniques offer attractive possibilities for other length scales, it is difficult to implement compartments in the mesoscale range of 10-100 nm. Herein we show how simple blending of reactive prepolymers is suitable to design new microgel morphologies with tailored compartments. We use poly(EEGE)-block-poly(AGE) as crosslinkable, pro-hydrophilic prepolymer in blends with varying amounts of crosslinkable, yet hydrophobic poly(THF-stat-AllylEHO) or inert and hydrophobic polystyrene, and crosslink the allyl functional prepolymer(s) in a thiol-ene click-type reaction after miniemulsification. Our strategy shows how arrested versus free nanophase separation can be used to control easily the morphology and polarity of microgel particles.

[Microvascular effects of burn plasma transfer and therapeutic options in a rat model]

INTRODUCTION

Thermal injuries with more than 20% of burned body surface area (BSA) lead to systemic shock with generalised oedema in addition to local tissue destruction. This condition, known as burn injury, is caused by immunmodulative mediators whose individual significance is not known in detail. We present an experimental model where plasma of burned animals (burn plasma) is transmitted to healthy animals, to trigger burn iniury without performing direct burn trauma.

MATERIAL AND METHODS

The systemic oedema is measured by extravasation of fluorescent albumin in mesenterial venules of Wistar rats. In addition, leukocyte-endothelial interactions ("leukocyte rolling and sticking") is examined.

RESULTS

The systemic capillary leak is induced by both direct thermal trauma as well as by infusion of burn plasma. This is evident even after plasma dilution (1% in Ringer's lactate) of the burn plasma. In addition, topical therapy for burned animals (donors) with cerium nitrate led to a significant reduction of plasma extravasation in receiver animals. In addition, systemic antioxidant therapy with high-dose vitamin C of receiver animals, led to a significant reduction of the capillary leak. Leukocyte-endothelial interactions are not significantly affected in either case.

CONCLUSION

In summary, for the first time a reliable model of burn injury has been established, which eliminates mediator-independent effects. In addition, our studies show that antioxidant therapy with high doses of vitamin C and topical treatment with cerium nitrate both reduce the systemic capillary leak in receiver animals. Their positive influence could therefore soon be integrated in clinical treatment algorithms.

Controlling fast transport of cold trapped ions

We realize fast transport of ions in a segmented microstructured Paul trap. The ion is shuttled over a distance of more than 10(4) times its ground state wave function size during only five motional cycles of the trap (280 μm in 3.6 μs). Starting from a ground-state-cooled ion, we find an optimized transport such that the energy increase is as low as 0.10±0.01 motional quanta. In addition, we demonstrate that quantum information stored in a spin-motion entangled state is preserved throughout the transport. Shuttling operations are concatenated, as a proof-of-principle for the shuttling-based architecture to scalable ion trap quantum computing.

[Outpatient anesthesia for patients with obstructive sleep apnea: results of a national survey]

BACKGROUND

In Germany there is currently no national standard for the management of patients with obstructive sleep apnea syndrome (OSAS). The object of this survey was to obtain information on the treatment concept for patients with OSAS and to report on the current practice in Germany.

METHODS

Data collection was obtained through an online questionnaire. A total of 12,113 members of the supporting anesthesia societies from all over Germany were invited to participate via e-mail. Additionally an announcement was made in a professional journal.

RESULTS

A total of 1,671 questionnaires were analyzed. The average age of the respondents was 45 years, 64% were male and 36% were female. The average work experience was 16 years and 85% of the respondents were consultants. In total 85% of anesthesiologists were predominantly working in inpatient care and 12% were predominantly active in outpatient care. Of the respondents 63% preferred regional anesthesia, 20% preferred general anesthesia for patients with OSAS and 17% did not have a preference for a specific anesthesia procedure. Outpatient surgery for patients with OSAS was performed by 72% of the respondents using regional anesthesia and by 55% of the respondents using local anesthesia with sedation. Of the anesthesiologists 49% consented to outpatient surgery using general anesthesia and 14% to interventions involving the airways. Compared to anesthesiologists working predominantly in inpatient departments, those working predominantly in outpatient departments treated patients with OSAS more frequently on an outpatient basis, used general anesthesia significantly more often, discharged those patients significantly earlier and observed less complications.

CONCLUSIONS

This survey shows that outpatient surgery for patients with sleep apnea is common practice in Germany. It is also performed when patients have moderate or severe OSAS and for respiratory tract surgery. This means that the management is not conform to the guidelines of the American Society of Anesthesiologists (ASA).

[Who dictates the rhythm which must be followed? : Pacemakers and implantable cardioverter defibrillators in anesthesiology]

The number of patients with implantable cardiac devices for the treatment of cardiac dysrhythmia is steadily climbing. Due to the increase in indications for implantation and the range of functions, an end to this development is not yet in sight. In order to provide safety in the everyday handling of these systems it is necessary to pay attention to various aspects prior to, during and after surgery or anesthesia.

Observing the phase space trajectory of an entangled matter wave packet

We observe the phase space trajectory of an entangled wave packet of a trapped ion with high precision. The application of a spin-dependent light force on a superposition of spin states allows for coherent splitting of the matter wave packet such that two distinct components in phase space emerge. We observe such motion with a precision of better than 9% of the wave packet extension in both momentum and position, corresponding to a 0.8 nm position resolution. We accurately study the effect of the initial ion temperature on the quantum entanglement dynamics. Furthermore, we map out the phonon distributions throughout the action of the displacement force. Our investigation shows corrections to simplified models of the system evolution. The precise knowledge of these dynamics may improve quantum gates for ion crystals and lead to entangled matter wave states with large displacements.

Storage and recall of weak coherent optical pulses with an efficiency of 25%

We demonstrate experimentally an efficient coherent rephasing scheme for the storage and recall of weak coherent light pulses in an inhomogeneously broadened optical transition in a Pr(3+):YSO crystal at 2.1 K. Precise optical pumping using a frequency stable (≈1  kHz linewidth) laser is employed to create a highly controllable atomic frequency comb structure. We report single photon level storage and retrieval efficiencies of 25%, based on coherent photon-echo-type reemission in the forward direction. The high efficiency is mainly a product of our highly controllable and precise ensemble-shaping technique. The coherence property of the quantum memory is proved through interference between a super-Gaussian pulse and the emitted echo.

[Anesthesiologic procedure for elective aortic surgery]

Aortic aneurysms are frequent in the elderly who often suffer from relevant co-morbidities. In Germany it is estimated that approximately 250,000 patients suffer from an aortic aneurysm. Due to the high risk of cardiac or pulmonary complications operative management poses a challenge to the anesthesiologist. Especially hemodynamic management during aortic cross-clamping requires anesthesiologic know-how and an anticipatory use of vasodilators and catecholamines. Furthermore, the anesthesiologist has to protect renal function. In order to avoid paraplegia due to spinal ischemia cerebrospinal fluid drainage may be necessary in patients with aneurysms of the thoracic aorta. In recent years endovascular repair of aortic aneurysms has been established in addition to conventional open surgery. As a consequence in some patients aortic surgery can be performed under regional or local anesthesia. In special cases thoracic endovascular repair requires a medicinal induction of heart arrest or the reduction of aortic blood flow by overpacing.

[Diagnosis, therapy and secondary prophylaxis of acute pulmonary embolism. Presentation of and commentary on the new ESC 2008 guidelines]

Acute venous thromboembolism is a common cardiovascular emergency. Acute pulmonary embolism (PE) is present in one third of these patients. With an average lethality rate of 11% within the first two weeks following diagnosis, approximately 40,000 patients in Germany die annually as a result of PE; therefore, their diagnosis and therapy is of particular importance. For this reason, the European Society of Cardiology published guidelines on diagnosis and therapy in 2000. The current article presents and discusses the points as updated and extended in the 2008 version of the guidelines, including: (1) initial risk stratification--when PE is already suspected; (2) diagnostic procedures and algorithms; (3) further risk stratification; (4) therapeutic strategies in the acute phase; (5) further management and (6) long-term anticoagulation and secondary prophylaxis.

Association between chromosomal instability and prognosis in colorectal cancer: a meta-analysis

BACKGROUND

Several studies have suggested that microsatellite instability (MSI) resulting from defective DNA mismatch repair confers a better prognosis in colorectal cancer (CRC). Recently, however, data have suggested this is secondary to the effects of ploidy/chromosomal instability (CIN). To estimate the prognostic significance of CIN for survival, data from published studies have been reviewed and pooled.

METHODS

Studies stratifying survival in CRC by CIN status were identified by searching PubMed and hand-searching bibliographies of identified studies. Two reviewers confirmed study eligibility and extracted data independently, and data were pooled using a fixed-effects model. The principal outcome measure was the HR for death.

RESULTS

63 eligible studies reported outcome in 10 126 patients, 60.0% of whom had CIN+ (aneuploid/polyploid) tumours. The overall HR associated with CIN was 1.45 (95% CI 1.35 to 1.55, p<0.001). In patients with stage II-III CRCs, the HR was 1.45 (95% CI 1.27 to 1.65, p<0.001). The effect was similar for progression-free survival (HR = 1.71, 95% CI 1.51 to 1.94, p<0.001). There was no evidence of significant interstudy heterogeneity.

CONCLUSION

CIN is associated with a worse prognosis in CRC, and should be evaluated as a prognostic marker, together with MSI status, in all clinical trials, particularly those involving adjuvant therapies.

Molecular diversity at 18 loci in 321 wild and 92 domesticate lines reveal no reduction of nucleotide diversity during Triticum monococcum (Einkorn) domestication: implications for the origin of agriculture

The diploid wheat Triticum monococcum L. (einkorn) was among the first crops domesticated by humans in the Fertile Crescent 10,000 years ago. During the last 5,000 years, it was replaced by tetraploid and hexaploid wheats and largely forgotten by modern breeders. Einkorn germplasm is thus devoid of breeding bottlenecks and has therefore preserved in unfiltered form the full spectrum of genetic variation that was present during its domestication. We investigated haplotype variation among >12 million nucleotides sequenced at 18 loci across 321 wild and 92 domesticate T. monococcum lines. In contrast to previous studies of cereal domestication, we sampled hundreds of wild lines, rather than a few dozen. Unexpectedly, our broad sample of wild lines reveals that wild einkorn underwent a process of natural genetic differentiation, most likely an incipient speciation, prior to domestication. That natural differentiation was previously overlooked within wild einkorn, but it bears heavily upon inferences concerning the domestication process because it brought forth 3 genetically, and to some extent morphologically, distinct wild einkorn races that we designate here as alpha, beta, and gamma. Only one of those natural races, beta, was exploited by humans for domestication. Nucleotide diversity and haplotype diversity in domesticate einkorn is higher than in its wild sister group, the einkorn beta race, indicating that einkorn underwent no reduction of diversity during domestication. This is in contrast to findings from previous studies of domestication history among more intensely bred crop species. Taken together with archaeological findings from the Fertile Crescent, the data indicate that a specific wild einkorn race that arose without human intervention was subjected to multiple independent domestication events.

Understanding laser stabilization using spectral hole burning

There have recently been several studies of the performance of laser frequency stabilization using spectral holes in solids, instead of an external cavity, as a frequency reference. Here an analytical theory for Pound-Drever-Hall laser frequency stabilization using spectral hole-burning is developed. The interaction between the atomic medium and the phase modulated light is described using a linearized model of the Maxwell-Bloch equations. The interplay between the carrier and modulation sidebands reveals significant differences from the case of locking to a cavity. These include a different optimum modulation index, an optimum sample absorption, and the possibility to lock the laser in an inherent linear frequency drift mode. Spectral holes in solids can be permanent or transient. For the materials normally used, the dynamics and time scales of transient holes often depend on population relaxation processes between ground state hyperfine levels. These relaxation rates can be very different for different solid state materials. We demonstrate, using radio-frequency pumping, that the hyperfine population dynamics may be controlled and tailored to give optimum frequency stabilization performance. In this way also materials with initially non-optimum performance can be used for stabilization. The theoretical predictions regarding the inherent linear frequency drift is compared to experimental data from a dye laser stabilized to a spectral hole in a Pr(3+)3+:Y(2)SiO(5) crystal.

A comparison of growing season indices for the Greater Baltic Area

Predictions of the effects of global warming suggest that climate change may have large impacts on ecosystems. The length of the growing season is predicted to increase in response to increasing global temperatures. The object of this study was to evaluate different indices used for calculating the thermal growing season for the Greater Baltic Area (GBA). We included established indices of growing season start, end and length, as well as new and modified indices. Based on the results, the GBA can be divided into a maritime western part and a more continental eastern part, with the western part reacting more sensitively to the use of different indices. The eastern part is more stable, but even here the index-to-index differences are large. It was found that including or excluding a frost criterion had a significant influence on the initiation of the growing season in the western, maritime, parts of the GBA. Frost has not the same importance for the end of the growing season. However, some end indices can result in a "never ending" growing season. When looking at twentieth century trends in growing season parameters, it was found that, when averaged over the whole GBA, there was little difference in trends depending on the indices used. The general mean trend in the GBA for the twentieth century discloses an earlier onset of c. 12 days, a delayed end of c. 8 days and consequently a lengthening of the growing season of about 20 days.

Deletion of the dynein heavy-chain gene DYN1 leads to aberrant nuclear positioning and defective hyphal development in Candida albicans

Cytoplasmic dynein is a microtubule-associated minus-end-directed motor protein. CaDYN1 encodes the single dynein heavy-chain gene of Candida albicans. The open reading frames of both alleles of CaDYN1 were completely deleted via a PCR-based approach. Cadyn1 mutants are viable but grow more slowly than the wild type. In vivo time-lapse microscopy was used to compare growth of wild-type (SC5314) and dyn1 mutant strains during yeast growth and after hyphal induction. During yeast-like growth, Cadyn1 strains formed chains of cells. Chromosomal TUB1-GFP and HHF1-GFP alleles were used both in wild-type and mutant strains to monitor the orientation of mitotic spindles and nuclear positioning in C. albicans. In vivo fluorescence time-lapse analyses with HHF1-GFP over several generations indicated defects in dyn1 cells in the realignment of spindles with the mother-daughter axis of yeast cells compared to that of the wild type. Mitosis in the dyn1 mutant, in contrast to that of wild-type yeast cells, was very frequently completed in the mother cells. Nevertheless, daughter nuclei were faithfully transported into the daughter cells, resulting in only a small number of multinucleate cells. Cadyn1 mutant strains responded to hypha-inducing media containing l-proline or serum with initial germ tube formation. Elongation of the hyphal tubes eventually came to a halt, and these tubes showed a defect in the tipward localization of nuclei. Using a heterozygous DYN1/dyn1 strain in which the remaining copy was controlled by the regulatable MAL2 promoter, we could switch between wild-type and mutant phenotypes depending on the carbon source, indicating that the observed mutant phenotypes were solely due to deletion of DYN1.