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Background: The shift of treatment of paediatric cancer patients to include more care at home puts a lot of pressure on health care professionals (HCPs) to prepare and train parents on safe and correct drug handling at home. Parents must take in and understand the information presented to them while coping with their own fear related to their child's cancer diagnosis. In Sweden, parents are expected to handle and manipulate oral anticancer drugs (OADs) in the home setting. There is however a lack of a standardized method to inform and educate parents on how to handle OADs in a correct way at home., Aim: To describe parents' experiences of handling OADs at home after participating in an educational intervention., Method: Educational intervention in the present study aimed to improve parents' knowledge in key concepts that is, handling OADs at home by using information presented in different forms. Fifteen parents to 12 children with cancer were recruited from a paediatric oncology ward in Sweden to participate in an interview. The interviews were transcribed verbatim and subjected to qualitative content analysis., Results: Parents' experiences are presented in categories: Relieved stress, Awareness of own exposure, Facilitated my everyday life, Parents need continued support individually. The educational intervention resulted in both positive and negative feelings, increased awareness of drug exposure and correct drug handling at home. Practical training and information presented in different ways facilitated the process of drug handling. To handle the drug correctly at home parents requested to be trained and informed in the beginning of their child's oral drug treatment. In addition, parents requested to be individually approached by HCP to get answers to questions and concerns., Conclusions: This educational intervention study shows promising results for the method used by HCPs to inform and educate parents on complicated topics such as handling OADs at home., (© 2024 The Author(s). Journal of Evaluation in Clinical Practice published by John Wiley & Sons Ltd.)

The isotope shifts in electron affinities of Pb were measured by Walter et al. [Phys. Rev. A 106, L010801 (2022)] to be -0.002(4) meV for 207-208Pb and -0.003(4) meV for 206-208Pb by scanning the threshold of the photodetachment channel Pb-(S3/2◦4) - Pb (3P0), while Chen and Ning reported 0.015(25) and -0.050(22) meV for the isotope shifts on the binding energies measured relative to 3P2 using the SEVI method [J. Chem. Phys. 145, 084303 (2016)]. Here we revisited these isotope shifts by using our second-generation SEVI spectrometer and obtained -0.001(15) meV for 207-208Pb and -0.001(14) meV for 206-208Pb, respectively. In order to aid the experiment by theory, we performed the first ab initio theoretical calculations of isotope shifts in electron affinities and binding energies of Pb, as well as the hyperfine structure of 207Pb-, by using the MCDHF and RCI methods. The isotope shifts in electron affinities of 207-208Pb and 206-208Pb are -0.0023(8) and -0.0037(13) meV for the 3P0 channel, respectively, in good agreement with Walter et al.'s measurements. The isotope shifts in binding energies relative to 3P1,2, -0.0015(8) and -0.0026(13) meV for 207-208Pb and 206-208Pb, respectively, are compatible with the present measurements. The hyperfine constant for the ground state of 207Pb- obtained by the present calculations, A(S3/2◦4)=-1118 MHz, differs by a factor of 3 from the previous estimation by Bresteau et al. [J. Phys. B: At., Mol. Opt. Phys. 52, 065001 (2019)]. The reliability is supported by the good agreement between the theoretical and experimental hyperfine parameters of 209Bi., (© 2024 Author(s). Published under an exclusive license by AIP Publishing.)

Background: Diseases affecting the lungs and airways contribute significantly to the global burden of disease. The problem in low- and middle-income countries appears to be exacerbated by a shift in global manufacturing base to these countries and inadequate enforcement of environmental and safety standards. In Ghana, the potential adverse effects on respiratory function associated with occupational wood dust exposure have not been thoroughly investigated., Methods: Sixty-four male sawmill workers and 64 non-woodworkers participated in this study. The concentration of wood dust exposure, prevalence and likelihood of association of respiratory symptoms with wood dust exposure and changes in pulmonary function test (PFT) parameters in association with wood dust exposure were determined from dust concentration measurements, symptoms questionnaire and lung function test parameters., Results: Sawmill workers were exposed to inhalable dust concentration of 3.09 ± 0.04 mg/m 3 but did not use respirators and engaged in personal grooming habits that are known to increase dust inhalation. The sawmill operators also showed higher prevalence and likelihoods of association with respiratory symptoms, a significant cross-shift decline in some PFT parameters and a shift towards a restrictive pattern of lung dysfunction by end of daily shift. The before-shift PFT parameters of woodworkers were comparable to those of non-woodworkers, indicating a lack of chronic effects of wood dust exposure., Conclusions: Wood dust exposure at the study site was associated with acute respiratory symptoms and acute changes in some PFT parameters. This calls for institution and enforcement of workplace and environmental safety policies to minimise exposure at sawmill operating sites, and ultimately, decrease the burden of respiratory diseases., Competing Interests: Competing interests: The authors declare that they have no competing interests., (Copyright © 2023 Korean Society of Occupational & Environmental Medicine.)

Background: Long term treatment of pediatric patients with oral anticancer drugs (OADs) requires the parents/caregivers to prepare the drug at home. The handling procedures in the home setting are, however, not regulated by Swedish law and the parents are often left without guidance on how to handle OADs in a safe way., Aim: The aim of this study was to increase understanding of how OADs are handled by parents/caregivers in the home setting before and after an intervention., Methods: Parents of pediatric cancer patients were observed and videotaped during their handling of OADs in the home setting before and after the intervention. During the intervention, the parents were provided with written instructions, movie clips and practical training on handling the OADs. Four checklists were used to compare and score the four handling procedures (measuring an oral suspension, cutting tablets, dissolving tablets, and opening capsules) for each parent before and after the intervention., Results: The intervention significantly improved the OAD handling procedures among the studied parents. The median score for correct handling was 19% (IQR: 3.6 to 30%) before the intervention and 89.5% (IQR: 71.5 to 94.5%) after the intervention (p < 0.0001)., Conclusions: An intervention comprising practical training and information presented in different forms improved the handling of OADs at home by parents. There is an urgent need to implement this method in all oncology centers in Sweden, educate HCPs to standardize the presentation of information. There is also a great need to provide parents with age-appropriate oral drug formulations from the local hospital pharmacies in Sweden.

The long theorized two-dimensional allotrope of SiC has remained elusive amid the exploration of graphenelike honeycomb structured monolayers. It is anticipated to possess a large direct band gap (2.5 eV), ambient stability, and chemical versatility. While sp^{2} bonding between silicon and carbon is energetically favorable, only disordered nanoflakes have been reported to date. Here we demonstrate large-area, bottom-up synthesis of monocrystalline, epitaxial monolayer honeycomb SiC atop ultrathin transition metal carbide films on SiC substrates. We find the 2D phase of SiC to be almost planar and stable at high temperatures, up to 1200 °C in vacuum. Interactions between the 2D-SiC and the transition metal carbide surface result in a Dirac-like feature in the electronic band structure, which in the case of a TaC substrate is strongly spin-split. Our findings represent the first step towards routine and tailored synthesis of 2D-SiC monolayers, and this novel heteroepitaxial system may find diverse applications ranging from photovoltaics to topological superconductivity.

Aim: The aim of this study was to describe the experiences of parents handling oral anticancer drugs in a home setting., Methods: Parents of children with cancer were recruited from a paediatric oncology ward in Sweden to participate in an interview. The interviews were transcribed verbatim and subjected to qualitative content analysis., Results: We found the following categories and subcategories: parents' views on the provided information-lack of, too little or contradictory information, and parents' preferences for information delivery; safety over time; correct drug dose; and drug administration. As time passed, most parents adapted to their child's illness, felt safer and found it easier to take in and process any given information. Parents preferred information in different formats (written, movie clips and orally) and in their mother tongue. Many parents were aware of the importance of giving an accurate dose to their child and described the process of drug administration as overwhelming., Conclusion: Parents need to be provided with accurate, timely, nonconflicting and repeated information-in different forms and in their mother tongue-on how to handle oral anticancer drugs at home., (© 2022 The Authors. Journal of Evaluation in Clinical Practice published by John Wiley & Sons Ltd.)

Background: Survivors of childhood cancer can develop adverse health events later in life. Infrequent occurrences and scarcity of structured information result in analytical and statistical challenges. Alternative statistical approaches are required to investigate the basis of late effects in smaller data sets., Methods: Here we describe sex-specific health care use, mortality and causal associations between primary diagnosis, treatment and outcomes in a small cohort ( n  = 2315) of 5-year survivors of childhood cancer ( n  = 2129) in southern Sweden and a control group ( n  = 11,882; age-, sex- and region-matched from the general population). We developed a constraint-based method for causal inference based on Bayesian estimation of distributions, and used it to investigate health care use and causal associations between diagnoses, treatments and outcomes. Mortality was analyzed by the Kaplan-Meier method., Results: Our results confirm a significantly higher health care usage and premature mortality among childhood cancer survivors as compared to controls. The developed method for causal inference identifies 98 significant associations ( p  < 0.0001) where most are well known ( n  = 73; 74.5%). Hitherto undescribed associations are identified ( n  = 5; 5.1%). These were between use of alkylating agents and eye conditions, topoisomerase inhibitors and viral infections; pituitary surgery and intestinal infections; and cervical cancer and endometritis. We discuss study-related biases ( n  = 20; 20.4%) and limitations., Conclusions: The findings contribute to a broader understanding of the consequences of cancer treatment. The study shows relevance for small data sets and causal inference, and presents the method as a complement to traditional statistical approaches., Competing Interests: Competing interestsThe authors declare no competing interests., (© The Author(s) 2022.)

An association between acute myocardial infarction (AMI) and systemic lupus erythematosus (SLE) has been suggested. The cause of AMI is presumed to be atherothrombosis. In the present study, the primary objective was to assess incident AMI cases and the secondary objective was to estimate the proportion of myocardial infarction with nonobstructive coronary arteries (MINOCA) in patients with SLE. All Swedish patients with SLE without AMI before 1996 (n = 4192) were followed for 20 years in the national patient registry. For each SLE patient, 10 age- and sex-matched controls without SLE and AMI before 1996 (n = 41 892) were identified. Data from patients and controls with AMI after 1996 were linked with the Swedish coronary angiography and angioplasty register; 549 (13%) and 3352 (8%) first AMIs occurred in patients with SLE and controls, respectively. The incidence of AMI was 9.6 (95% CI: 8.9-10.5) and 4.9 (95% CI: 4.8-5.1) events/1000 person-years in patients with SLE and controls, respectively. The proportion of MINOCA was 10.8% in patients with SLE and 13.8% in controls ( P = .261), respectively. In conclusion, the incidence of AMI is increased in a European population of patients with SLE but there is no indication that the proportion of MINOCA is increased in these patients.

Alterations of the mycobiota composition associated with Crohn's disease (CD) are challenging to link to defining elements of pathophysiology, such as poor injury repair. Using culture-dependent and -independent methods, we discovered that Debaryomyces hansenii preferentially localized to and was abundant within incompletely healed intestinal wounds of mice and inflamed mucosal tissues of CD human subjects. D. hansenii cultures from injured mice and inflamed CD tissues impaired colonic healing when introduced into injured conventionally raised or gnotobiotic mice. We reisolated D. hansenii from injured areas of these mice, fulfilling Koch's postulates. Mechanistically, D. hansenii impaired mucosal healing through the myeloid cell-specific type 1 interferon-CCL5 axis. Taken together, we have identified a fungus that inhabits inflamed CD tissue and can lead to dysregulated mucosal healing., (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Objectives: To assess whether changes in patterns of combined oral contraceptive (COC) prescriptions to starters between 2008 and 2016 were in line with changes in national recommendations for use., Design: Historical prospective cohort study., Setting: The national Norwegian Prescription Database., Participants: Women aged 10-49 years who started COCs between 1 January 2008 and 30 June 2016, in total 285 009 women., Primary Outcome: The proportion of levonorgestrel-containing COC prescriptions to starters., Intervention: The Norwegian Medical Agency recommended levonorgestrel-containing COCs to starters from 2010 onwards., Results: The proportion of levonorgestrel-containing COCs prescribed to starters increased from 41% in 2008 to 80% in 2016 with the greatest increase from 2011 to 2012. This prescription pattern comprised all age groups but was observed to a lower extent among older women. Public health nurses and midwifes had the highest compliance with recommendations and prescribed levonorgestrel-containing COCs to 96% of starters aged <20 years in 2016, compared with 75% and 86% among general practitioners and doctors with no specialty., Conclusion: All professions have increased the proportion of levonorgestrel-containing COC prescriptions to starters. Public health nurses and midwives had the highest compliance with the new recommendations. Future studies will examine whether this shift in prescription pattern has prevented venous thromboembolism in women of reproductive age in Norway., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Regulation of intestinal epithelial turnover is a key component of villus maintenance in the intestine. The balance of cell turnover can be perturbed by various extrinsic factors including the cytokine TNF, a cell signaling protein that mediates both proliferative and cytotoxic outcomes. Under conditions of infection and damage, defects in autophagy are associated with TNF-mediated cell death and tissue damage in the intestinal epithelium. However, a direct role of autophagy within the context of enterocyte cell death during homeostasis is lacking. Here, we generated mice lacking ATG14 (autophagy related 14) within the intestinal epithelium [ Atg14 f/f Vil1- Cre ( VC ) + ]. These mice developed spontaneous villus loss and intestinal epithelial cell death within the small intestine. Based on marker studies, the increased cell death in these mice was due to apoptosis. Atg14 f/f VC + intestinal epithelial cells demonstrated sensitivity to TNF-triggered apoptosis. Correspondingly, both TNF blocking antibody and genetic deletion of Tnfrsf1a/Tnfr1 rescued villus loss and cell death phenotype in Atg14 f/f VC + mice. Lastly, we identified a similar pattern of spontaneous villus atrophy and cell death when Rb1cc1 / Fip200 was conditionally deleted from the intestinal epithelium ( Rb1cc1 f/f VC + ). Overall, these findings are consistent with the hypothesis that factors that control entry into the autophagy pathway are also required during homeostasis to prevent TNF triggered death in the intestine. Abbreviations: ANOVA: analysis of variance; Atg14 : autophagy related 14; Atg16l1 : autophagy related 16-like 1 (S. cerevisiae); Atg5 : autophagy related 5; cCASP3: cleaved CASP3/caspase-3; cCASP8: cleaved CASP8/caspase-8; CHX: cycloheximide; EdU: 5-ethynyl-2´-deoxyuridine thymidine; f/f: flox/flox; H&E: hematoxylin and eosin; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; Nec-1: necrostatin-1; Rb1cc1/Fip200 : RB1-inducible coiled-coil 1; Ripk1 : receptor (TNFRSF)-interacting serine-threonine kinase 1; Ripk3 : receptor (TNFRSF)-interacting serine-threonine kinase 3; Tnfrsf1a/Tnfr1 : tumor necrosis factor receptor superfamily, member 1a; Tnf/ Tnfsf1a : tumor necrosis factor; VC: Vil1/villin 1 -Cre.

A Comment on the Letter by Mendoza and Bautista [Phys. Rev. Lett. 118, 163002 (2017)PRLTAO0031-900710.1103/PhysRevLett.118.163002].

Life history theory is an essential framework to understand the evolution of reproductive allocation. It predicts that individuals of long-lived species favour their own survival over current reproduction, leading individuals to refrain from reproducing under harsh conditions. Here we test this prediction in a long-lived bird species, the Siberian jay Perisoreus infaustus. Long-term data revealed that females rarely refrain from breeding, but lay smaller clutches in unfavourable years. Neither offspring body size, female survival nor offspring survival until the next year was influenced by annual condition, habitat quality, clutch size, female age or female phenotype. Given that many nests failed due to nest predation, the variance in the number of fledglings was higher than the variance in the number of eggs and female survival. An experimental challenge with a novel pathogen before egg laying largely replicated these patterns in two consecutive years with contrasting conditions. Challenged females refrained from breeding only in the unfavourable year, but no downstream effects were found in either year. Taken together, these findings demonstrate that condition-dependent reproductive allocation may serve to maintain female survival and offspring quality, supporting patterns found in long-lived mammals. We discuss avenues to develop life history theory concerning strategies to offset reproductive costs., (© 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.)

To benchmark a Monte Carlo model of the Auger cascade that has been developed at the Australian National University (ANU) against the literature data. The model is applicable to any Auger-electron emitting radionuclide with nuclear structure data in the format of the Evaluated Nuclear Structure Data File (ENSDF). Schönfeld's algorithms and the BrIcc code were incorporated to obtain initial vacancy distributions due to electron capture (EC) and internal conversion (IC), respectively. Atomic transition probabilities were adopted from the Evaluated Atomic Data Library (EADL) for elements with atomic number, Z = 1-100. Atomic transition energies were evaluated using a relativistic Dirac-Fock method. An energy-restriction protocol was implemented to eliminate energetically forbidden transitions from the simulations. Calculated initial vacancy distributions and average energy spectra of 123 I, 124 I, and 125 I were compared with the literature data. In addition, simulated kinetic energy spectra and frequency distributions of the number of emitted electrons and photons of the three iodine radionuclides are presented. Some examples of radiation spectra of individual decays are also given. Good agreement with the published data was achieved except for the outer-shell Auger and Coster-Kronig transitions. Nevertheless, the model needs to be compared with experimental data in a future study.

The avian family Paridae (tits and chickadees) contains c. 55 species distributed in the Palearctic, Nearctic, Afrotropics and Indomalaya. The group includes some of the most well-known and extensively studied avian species, and the evolutionary history, in particular the post-glacial colonization of the northern latitudes, has been comparably well-studied for several species. Yet a comprehensive phylogeny of the whole clade is lacking. Here, we present the first complete species phylogeny for the group based on sequence data from two nuclear introns and one mitochondrial gene for 67 taxa of parids. Our results strongly support the inclusion of the Fire-capped Tit (Cephalopyrus flammiceps), currently placed in the Remizidae, as the most basal member of the Paridae. The Yellow-browed Tit (Sylviparus modestus) and the Sultan Tit (Melanochlora sultanea) constitute the next two sequential branches whereas the remaining tits fall into two large clades, one of which contains the seed hoarding and nest excavating species. The indicated clades within these two groups are largely congruent with recent classifications, but with several unforeseen relationships, such as non-monophyly of the Sombre Tit (Poecile lugubris) and the Marsh Tit (Poecile palustris), as well as non-monophyly of both the African gray and the African black tits. Further, our results support a close relationship between the White-fronted Tit (Parus semilarvatus) and the varied Tit (Poecile varius) as well as a close relationship between the White-naped Tit (Parus nuchalis) and the Yellow-cheeked and Black-lored tits (Parus spilonotus and P. xanthogenys). Finally, Hume's Ground-tit (Pseudopodoces humilis) is found to be closely related to the Green-backed Tit (Parus monticolus) and the Great Tit (Parus major). We propose a new classification that is in accordance with this phylogeny., (Copyright © 2013 Elsevier Inc. All rights reserved.)

1. There are a number of models describing population structure, many of which have the capacity to incorporate spatial habitat effects. One such model is the source-sink model, that describes a system where some habitats have a natality that is higher than mortality (source) and others have a mortality that exceeds natality (sink). A source can be maintained in the absence of migration, whereas a sink will go extinct. 2. However, the interaction between population dynamics and habitat quality is complex, and concerns have been raised about the validity of published empirical studies addressing source-sink dynamics. In particular, some of these studies fail to provide data on survival, a significant component in disentangling a sink from a low quality source. Moreover, failing to account for a density-dependent increase in mortality, or decrease in fecundity, can result in a territory being falsely assigned as a sink, when in fact, this density-dependent suppression only decreases the population size to a lower level, hence indicating a 'pseudo-sink'. 3. In this study, we investigate a long-term data set for key components of territory-specific demography (mortality and reproduction) and their relationship to habitat characteristics in the territorial, group-living Siberian jay (Perisoreus infaustus). We also assess territory-specific population growth rates (r), to test whether spatial population dynamics are consistent with the ideas of source-sink dynamics. 4. Although average mortality did not differ between sexes, habitat-specific mortality did. Female mortality was higher in older forests, a pattern not observed in males. Male mortality only increased with an increasing amount of open areas. Moreover, reproductive success was higher further away from human settlement, indicating a strong effect of human-associated nest predators. 5. Averaged over all years, 76% of the territories were sources. These territories generally consisted of less open areas, and were located further away from human settlement. 6. The source-sink model provides a tool for modelling demography in distinct habitat patches of different quality, which can aid in identifying key habitats within the landscape, and thus, reduce the risk of implementing unsound management decisions.

Food packaging papers are not sterile, as the manufacturing is an open process, and the raw materials contain bacteria. We modeled the potential transfer of the Bacillus cereus spores from packaging paper to food by using a green fluorescent protein-expressing construct of Bacillus thuringiensis Bt 407Cry(-) [pHT315Omega(papha3-gfp)], abbreviated BT-1. Paper (260 g m(-2)) containing BT-1 was manufactured with equipment that allowed fiber formation similar to that of full-scale manufactured paper. BT-1 adhered to pulp during papermaking and survived similar to an authentic B. cereus. Rice and chocolate were exposed to the BT-1-containing paper for 10 or 30 days at 40 or 20 degrees C at relative air humidity of 10 to 60%. The majority of the spores remained immobilized inside the fiber web; only 0.001 to 0.03% transferred to the foods. This amount is low compared with the process hygiene criteria and densities commonly found in food, and it does not endanger food safety. To measure this, we introduced BT-1 spores into the paper in densities of 100 to 1,000 times higher than the amounts of the B. cereus group bacteria found in commercial paper. Of BT-1 spores, 0.03 to 0.1% transferred from the paper to fresh agar surface within 5 min of contact, which is more than to food during 10 to 30 days of exposure. The findings indicate that transfer from paper to dry food is restricted to those microbes that are exposed on the paper surface and readily detectable with a contact agar method.

Deinococcus geothermalis has frequently been isolated from pink colored deposits of paper industry processes. Laboratory studies have shown that D. geothermalis is capable of forming on nonliving surfaces patchy biofilms that are resistant to adverse agents such as extreme pH, desiccation, solubilising detergents and biocides. This study was done to quantitatively assess the role of D. geothermalis as a biofouler in paper industry. Colored deposits were collected from 24 European and North American paper and board machines and the densities of the bacterial 16S rRNA genes and those of the red slime producers D. geothermalis and Meiothermus spp. were measured by QPCR (quantitative real time PCR). D. geothermalis was found at nine machines, usually from splash area deposits, but its contribution was minor, 0.001-1%, to the total bacterial burden of 8.3 to log 10.5 log units per gram wet-weight of the deposits. When D. geothermalis was found in a measurable quantity, Meiothermus spp. also was found, often in bulk quantity (7-100% of the total bacteria). The data are in line with the properties of D. geothermalis known from laboratory biofilm studies, indicating this species is a pioneer coloniser of machine surfaces and may help other bacteria to adhere and grown into biofilms, rather than competing with them.

The tendency in the paper industry is to close all water loops to save water. This leads to higher process temperatures and may increase the colloidal and dissolved material in the process circulation. Increase of nutrients in the water circuits may favor microbiological growth and fouling. In this paper the chemical and microbial compositions of water circuits and deposits were studied of two closed cycled paper/board mills, one mill totally closed (0 m(3) waste water t(-1)), and the other low discharging (about 4 m(3 )t(-1)). The zero discharge mill accumulated high amounts (>10 g C L(-1)) of organic carbon in the circulation waters, about 40% of which composed of volatile acids (lactic, acetic, propionic and butyric acid). Water contents of sulfate, chloride, sodium and calcium increased to >1 g L(-1) of each. q-PCR targeted on 16S rRNA genes indicated that the bacteria in water circuits were mainly viable cells. In both mills anaerobic growth (10(6)-10(8) CFU mL(-1)) equalled or exceeded aerobic growth, with odor problem but no actual slime problem. The major part (40%) of all identifiable bacterial sequences were closest but yet distant (<96%) to Enterococcus cecorum and in the 4 m(3 )t(-1) discharging mill also Bacillus thermoamylovorans and Bacillus coagulans. Slimes and deposits from the mills contained high amounts, > or =10(8) g(-1), of archaean, but only the genus Methanothrix was identifiable from the cloned sequences. The findings indicate that closing the water circuits strongly limited diversity of the microbiota but allowed efficient mineralization of the dissolved and suspended matter.

In retrospective radon measurements, the 22-y half life of (210)Pb is used as an advantage. (210)Pb is often considered to be relatively immobile in glass after alpha recoil implanted by (222)Rn progenies. The diffusion of (210)Pb could, however, lead to uncertain wrong retrospective radon exposure estimations if (210)Pb is mobile and can escape from glass, or lost as a result of cleaning-induced surface modification. This diffusion was studied by a radiotracer technique, where (209)Pb was used as a tracer in a glass matrix for which the elemental composition is known. Using the ion guide isotope separator on-line technique, the (209)Pb atoms were implanted into the glass with an energy of 39 keV. The diffusion profiles and the diffusion coefficients were determined after annealing at 470-620 degrees C and serial sectioning by ion sputtering. In addition, the effect of surface cleaning on diffusion was tested. From the Arrhenius fit, the activation enthalpy (H) was determined, which is equal to 3.2 +/- 0.2 eV, and also the pre-exponential factor D(0), in the order of 20 m(2)s(-1). This result confirms the assumption that over a time period of 50 y (209)Pb (and (210)Pb) is effectively immobile in the glass. The boundary condition obtained from the measurements had the characteristic of a sink, implying loss of (209)Pb in the topmost surface at high temperatures.

An analysis of reproductive success in the green woodhoopoe Phoeniculus purpures challenges the view that delayed dispersal is costly. Females delaying dispersal for longer had more reproductive events in life and higher lifetime production of offspring.

In the boreal forests of Fennoscandia, over 99% of forest area has been altered by forestry practices, which has created forest with age structures and stand characteristics that differ from primary forest stands. Although many researchers have investigated how forestry affects species abundance, few have assessed how forestry practices affect fitness correlates of species living in altered habitats, and this has negatively affected management efforts. We experimentally addressed the effect of standard forestry practices on fitness correlates of an open-nesting, long-lived bird species typical to boreal forests of Eurasia, the Siberian Jay (Perisoreus infaustus). We used a before-after comparison of reproductive data on the level of territories and found that standard forestry practices had a strong negative effect on the breeding success of jays. Both partial thinning of territories and partial clearcutting of territories reduced future breeding success by a factor of 0.35. Forestry practices reduced territory occupancy. Thus, over the 15 years of the study, productivity of the affected population declined over 50% as a result of territory abandonment and reduced breeding success. Results of previous studies on Siberian Jays suggest that the strong effect of forest thinning on fitness is explained by the fact that most common predators of nests and adults are visually oriented and thus thinning makes prey and nests more visible to predators. The consequences of thinning we observed are likely to apply to a wide range of species that rely on understory to provide visual protection from predators. Thus, our results are important for the development of effective conservation management protocols and for the refinement of thinning practices.

Colored biofilms cause problems in paper industry. In this work we used real-time PCR to detect and to quantitate members of the genus Meiothermus from the process samples and end products from 24 machines manufacturing pulp, paper and board in four countries. The results obtained from 200 samples showed the importance of members of the genus Meiothermus as ubiquitous biofoulers in paper machines. This genus was the dominant biofouler in some mills. From < or =10(4) to 10(11) copies of Meiothermus 16S rRNA genes were found per gram of process deposit (wet weight). Meiothermus spp. were found in paper and board products with colored defects and connection between deposit-forming microbes and end-product spots was shown. 16S rRNA gene sequences of 29 biofilm producing bacterial isolates from different mills were determined. Based on sequence data, 25 of the isolates were assigned to the genus Meiothermus, with Meiothermus silvanus and M. ruber as the most frequent species.

Gamma decays from excited states up to Jpi=6+ in the N=Z-2 nucleus 54Ni have been identified for the first time. Level energies are compared with those of the isobars 54Co and 54Fe and of the cross-conjugate nuclei of mass A=42. The good but puzzling f7/ cross-conjugate symmetry in mirror and triplet energy differences is analyzed. Shell model calculations reproduce the new data but the necessary nuclear charge-dependent phenomenology is not fully explained by modern nucleon-nucleon potentials.

Excited states have been observed in the N=Z-2 odd-odd nucleus 48Mn for the first time. Through comparison with the structure of 48V, a first high-spin study of an odd-odd mirror pair has been achieved. Differences between the T=1 analogue states in this pair have been interpreted in terms of Coulomb effects, with the aid of shell-model calculations in the full pf valence space. Unlike other mirror pairs, the energy differences have been interpreted almost entirely as due to a monopole effect associated with smooth changes in radius (or deformation) as a function of angular momentum. In addition, the large energy shift between analogue negative-parity states is interpreted in terms of the electromagnetic spin-orbit interaction in nuclei.

Delayed dispersal is the key to family formation in most kin-societies. Previous explanations for the evolution of families have focused on dispersal constraints. Recently, an alternative explanation was proposed, emphasizing the benefits gained through philopatry. Empirical data have confirmed that parents provide their philopatric offspring with preferential treatment through enhanced access to food and predator protection. Yet it remains unclear to what extent such benefits translate into fitness benefits such as reduced mortality, which ultimately can select for the evolution of families. Here, we demonstrate that philopatric Siberian jay (Perisoreus infaustus) offspring have an odds ratio of being killed by predators 62% lower than offspring that dispersed promptly after independence to join groups of unrelated individuals (20.6% versus 33.3% winter mortality). Predation was the sole cause of mortality, killing 20 out of 73 juveniles fitted with radio tags. The higher survival rate among philopatric offspring was associated with parents providing nepotistic predator protection that was withheld from unrelated group members. Natal philopatry usually involves the suppression of personal reproduction. However, a lower mortality of philopatric offspring can overcome this cost and may thus select for the formation of families and set the scene for cooperative kin-societies.

Kin-based societies, where families represent the basic social unit, occur in a relatively small number of vertebrate species. In the majority of avian kin societies, families form when offspring prolong their association with the parents on the natal territory. Therefore, the key to understanding the evolution of families in birds is to understand natal philopatry (i.e. the tendency to remain on the natal territory). It has been shown that, within populations, the strength of the association between parents and offspring (i.e. family stability) increases when offspring dispersal is constrained by external environmental factors, but it is unclear whether and how family wealth influences juvenile dispersal decisions. Here, we show that young carrion crows (Corvus corone corone) from territories that were food-supplemented year-round were more philopatric and more likely to help at their family's nest than the unfed ones. The results suggest that offspring philopatry and helping behaviour are influenced by the quality of 'home' and that the availability of food resources positively affects the cohesion of the family.

A 2 Gb/s0.5 microm complementary metal-oxide semiconductor optical transceiver designed for board- or backplane level power-efficient interconnections is presented. The transceiver supports optical wake-on-link (OWL), an event-driven dynamic power-on technique. Depending on external events, the transceiver resides in either the active mode or the sleep mode and switches accordingly. The active-to-sleep transition shuts off the normal, gigabit link and turns on dedicated circuits to establish a low-power (approximately 1.8 mW), low data rate (less than 100 Mbits/s) link. In contrast the normal, gigabit link consumes over 100 mW. Similarly the sleep-to-active transition shuts off the low-power link and turns on the normal, gigabit link. The low-power link, sharing the same optical channel with the normal, gigabit link, is used to achieve transmitter/receiver pair power-on synchronization and greatly reduces the power consumption of the transceiver. A free-space optical platform was built to evaluate the transceiver performance. The experiment successfully demonstrated the event-driven dynamic power-on operation. To our knowledge, this is the first time a dynamic power-on scheme has been implemented for optical interconnects. The areas of the circuits that implement the low-power link are approximately one-tenth of the areas of the gigabit link circuits.

Cooperative breeding is comparatively rare among birds in the mainly temperate and boreal Northern Hemisphere. Here we test if the distribution of breeding systems reflects a response to latitude by means of a phylogenetic analysis using correlates with geographical range among the corvids (crows, jays, magpies and allied groups). The corvids trace their ancestry to the predominantly cooperative 'Corvida' branch of oscine passerines from the Australo-Papuan region on the ancient Gondwanaland supercontinent, but we could not confirm the ancestral state of the breeding system within the family, while family cohesion may be ancestral. Initial diversification among pair-breeding taxa that are basal in the corvid phylogeny, represented by genera such as Pyrrhocorax and Dendrocitta, indicates that the corvid family in its current form could have evolved from pair-breeding ancestors only after they had escaped the Australo-Papuan shield. Within the family, cooperative breeding (alloparental care/family cohesion) is strongly correlated to latitude and its predominance in species maintaining a southerly distribution indicates a secondary evolution of cooperative breeding in the lineage leading away from the basal corvids. Multiple transitions show plasticity in the breeding system, indicating a response to latitude rather than evolutionary inertia. The evolutionary background to the loss of cooperative breeding among species with a northerly distribution is complex and differs between species, indicating a response to a variety of selection forces. Family cohesion where the offspring provide alloparental care is a main route to cooperatively breeding groups among corvids. Some corvid species lost only alloparental care, while maintaining coherent family groups. Other species lost family cohesion and, as a corollary, they also lost the behaviour where retained offspring provide alloparental care.

Life-history theory predicts that an individual should reduce its reproductive efforts by laying a smaller clutch size when high risk of nest predation reduces the value of current reproduction. Evidence in favour of this 'nest predation hypothesis', however, is scarce and based largely on correlative analyses. Here, we manipulated perceived risk of nest predation in the Siberian jay Perisoreus infaustus using playback involving a mixture of calls by corvid nest predators in the vicinity of nest sites. In response to being exposed to this acoustic cue simulating increased risk of nest predation, the jays chose a nest site offering more protective covering and reduced clutch size. This is the first experimental demonstration of clutch size adjustment and nest site selection as a result of phenotypic plasticity in an open nesting passerine reflecting a facultative response to the perceived risk of nest predation.

High-spin states in 58Ni have been investigated by means of the fusion-evaporation reaction 28Si(32S, 2p)58Ni at 130 MeV beam energy. Discrete-energy levels are observed in 58Ni at record-breaking 42 MeV excitation energy and angular momenta in excess of 30h. The states form regular rotational bands with unprecedented high rotational frequencies. A comparison with configuration dependent cranked Nilsson-Strutinsky calculations reveals an exceptional two-band crossing scenario, the interaction strength of which is strongly shape dependent.

A dual-rate (2 Gbit/s and 100 Mbit/s) optical transceiver designed for power-efficient connections within and between modern high-speed digital systems is described. The transceiver can dynamically adjust its data rate according to performance requirements, allowing for power-on-demand operation. Dynamic power management permits energy saving and lowers device operating temperatures, improving the reliability and lifetime of optoelectronic-devices such as vertical-cavity surface-emitting lasers (VCSELs). To implement dual-rate functionality, we include in the transmitter and receiver circuits separate high-speed and low-power data path modules. The high-speed module is designed for gigabit operation to achieve high bandwidth. A simpler low-power module is designed for megabit data transmission with low power consumption. The transceiver is fabricated in a 0.5 microm silicon-on-sapphire complementary metal-oxide semiconductor. The VCSEL and photodetector devices are attached to the transceiver's integrated circuit by flip-chip bonding. A free-space optical link system is constructed to demonstrate correct dual-rate functionality. Experimental results show reliable link operation at 2 Gbit/s and 100 Mbit/s data transfer rates with approximately 104 and approximately 9 mW power consumption, respectively. The transceiver's switching time between these two data rates is demonstrated as 10 micros, which is limited by on-chip register reconfiguration time. Improvement of this switching time can be obtained by use of dedicated input-output pads for dual-rate control signals.

Optical links are traditionally set to transmit maximum power for worst-case loss and consequently to dissipate more power than is required. We describe a technique to minimize power consumption based on the measured bit-error rate (BER) of the link. This technique uses a novel power-negotiation algorithm that optimizes the link power setting to achieve minimum power dissipation for a target BER. A 0.5 microm complementary metal-oxide semiconductor optical transceiver chip was fabricated, and a free-space optical interconnect system was built for validation. The results showed that the algorithm was able to find the optimum power settings for the VCSELs for a target BER and to account for dynamic changes such as variation in the optical loss in the system.

We have completed a preliminary series of experiments that compare the silicate shells of the marine organism diatoms to Single-Wall NanoTubes (SWNT), Multi-Wall NanoTubes (MWNT), Exfoliated Graphite (EG), and silica as templates for producing nanostructures of the manganese acetate cluster Mn12 (Mn12[CH3(COO)16(H2O)4O12].(2)CH3COOH.4H2O). Mn12 exhibits magnetic properties because of the molecular arrangement within the cluster and exhibits no exchange couplings between the individual clusters. Data from scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), and laser diffraction are discussed in terms of research that can expand the use of diatoms and other materials as templates for nanostructures.

Following the heavy-ion fusion-evaporation reaction 32S+24Mg at 95 MeV beam energy the lifetimes of analogue states in the T(z)=+/-1/2 A=51 mirror nuclei 51Fe and 51Mn have been measured using the Cologne plunger device coupled to the GASP gamma-ray spectrometer. The deduced B(E2;27/2(-)-->23/2(-)) values afford a unique opportunity to probe isoscalar and isovector polarization charges and to derive effective proton and neutron charges, epsilon(p) and epsilon(n), in the fp shell. A comparison between the experimental results and several different large-scale shell-model calculations yields epsilon(p) approximately 1.15e and epsilon(n) approximately 0.80e.

Sjögren's syndrome (SS) is an incurable, autoimmune exocrinopathy that predominantly affects females and whose pathogenesis remains unknown. Like rheumatoid arthritis, its severity increases after menopause, and estrogen deficiency has been implicated. We have reported that estrogen receptor-alpha and -beta-knockout mice develop autoimmune nephritis and myeloid leukemia, respectively, but neither develops SS. One model of estrogen deficiency in rodents is the aromatase-knockout (ArKO) mouse. In these animals, there is elevated B lymphopoiesis in bone marrow. We now report that ArKO mice develop severe autoimmune exocrinopathy resembling SS. By 1 year of age, there is B cell hyperplasia in the bone marrow, spleen, and blood of ArKO mice and spontaneous autoimmune manifestations such as proteinuria and severe leukocyte infiltration in the salivary glands and kidney. Also, as is typically found in human SS, there were proteolytic fragments of alpha-fodrin in the salivary glands and anti-alpha-fodrin antibodies in the serum of both female and male ArKO mice. When mice were raised on a phytoestrogen-free diet, there was a mild but significant incidence of infiltration of B lymphocytes in WT mice and severe destructive autoimmune lesions in ArKO mice. In age-matched WT mice fed a diet containing normal levels of phytoestrogen, there were no autoimmune lesions. These results reveal that estrogen deficiency results in a lymphoproliferative autoimmune disease resembling SS and suggest that estrogen might have clinical value in the prevention or treatment of this disease.

Isocyanates may be harmful to workers and methods for monitoring air exposure in the field are necessary. The main aim of this study was to study the field performance of a method using 1-(2-methoxyphenyl)piperazine (2MP)-impregnated filters, by side-by-side comparison of long-term sampling with consecutive short-term samplings and also by short-term comparisons with other methods. Apart from using 2MP-impregnated filters, air monitoring was also performed by a modified 2MP method (FINMP) and by an impinger method using dibutylamine (DBA), which was the reference method. For short-term sampling the compared methods performed equally well for 2,6-toluenediisocyanate (2,6-TDI) and for isocyanic acid. For 2,4-toluenediisocyanate (2,4-TDI), the DBA method gave approximately 10% higher results according to linear regression than the 2MP method and for phenyl isocyanate, the DBA method gave significantly higher results than both the 2MP and FINMP methods. During long-term sampling (2-4 h) of TDI with the 2MP method, significantly lower levels were found compared with parallel sampling with consecutive short-term samplings. A time-dependent correction factor for long-term sampling was calculated to be 1.7 for 2,4-TDI and 1.5 for 2,6-TDI for 4 h sampling. The long-term sampling performance for other isocyanates was not studied. In conclusion, short-term monitoring shows that the 2MP method slightly underestimates the true air concentration for some of the isocyanates studied, but the error is relatively small considering the variation in exposure. For long-term monitoring the 2MP method can be applied for TDI but, since the method underestimates the concentrations, a correction factor is needed which needs to be corroborated further.

Excited states have been studied in 35Ar following the 16O(24Mg,1alpha1n)35Ar fusion-evaporation reaction at 60 MeV using the Ge-detector array GASP. A comparison with the mirror nucleus 35Cl shows two remarkable features: (i) A surprisingly large energy difference for the 13/2(-) states, in which the hitherto overlooked electromagnetic spin-orbit term is shown to play a major role, and (ii) a very different decay pattern for the 7/2(-) states, which provides direct evidence of isospin mixing.

In most cooperative vertebrates, delayed natal dispersal is the mechanism that leads to the formation of kin societies. Under this condition, the possibility that kin-based cooperative breeding is an unselected consequence of dispersal patterns can never be ruled out because helpers can only help their relatives. Here we show that a population of carrion crows (Corvus corone corone) fully fits the central prediction of kin selection theory that cooperative breeding should arise among relatives. On their territory, resident breeders are aided not only by nonbreeding retained offspring but also by immigrants (mainly males), with whom they share matings. Philopatry cannot account, however, for the high degree of genetic relatedness found between breeders and immigrants of the same sex that cooperate at a nest, indicating that crows actively choose to breed cooperatively with their relatives.

The relative roles of ecological constraints, the benefits of philopatry, and the role of life history continue to be debated in the evolution of natal philopatry and cooperative breeding. We compare three routes to breeding: departing to search for territories as a floater, staying and queuing to inherit the natal territory, or queuing and eventually shifting to a neighboring vacancy. Our model assumed a dominance-structured population. It quantifies the benefits of philopatry for varying-rank subordinates and contrasts it against the benefit of dispersal. We apply the model to data on Siberian jay Perisoreus infaustus, a species in which retained offspring do not help at the nest. The results indicate that territorial inheritance plays a small role in this species (presumably due to inbreeding avoidance), and territory acquisition is less constrained for dispersing than philopatric offspring. Nevertheless, small family groups-one or, at the most, two same-sex queuers-are predicted to form because philopatric offspring gain nepotistic benefits that improve their survival. This fits with data on group sizes and supports the idea of the natal territory as a safe haven for waiting for breeding opportunities. We also discuss our predictions in the light of ecological constraints and clarify recent confusingly different predictions on the role of habitat saturation as an explanation for delayed dispersal and cooperative breeding. We argue that "ecological constraint" is too wide a term to yield useful predictive power and that it is more appropriate to examine the consequences of specific life-history traits on the success of dispersers.

A diffusive sampling method for determination of methyl isocyanate in air has been developed. A glass fibre filter impregnated with 1-(2-methoxyphenyl)piperazine in a commercially available diffusive sampling device was used to collect methyl isocyanate and the derivative formed was analysed with LC-MS/MS. The sampling rate was determined to be 15.6 ml min(-1), with a relative standard deviation of 7.3%. The sampler was validated for sampling periods from 15 min to 8 h, for relative humidities from 20% to 80% and for concentrations from I to 46 microg m(-3). A field validation was also made and the diffusive sampling results showed no difference compared to a pumped reference method. The impregnated filters have to be stored apart from the diffusive sampler housing and loaded into the sampler prior to each sampling.

Approximately 3% of all bird species live in families based on a prolonged parent-offspring association. Formation of family groups often appears to be associated with various constraints on the possibilities of independent reproduction for the offspring. However, delayed dispersal is not the only alternative for offspring that defer reproduction. To account for the formation of a family group it is also necessary to explain why non-dispersing offspring forego the alternative options to join other groups as 'extra birds' or to become 'floaters' and roam between territories. We removed fathers from Siberian jay Perisoreus infaustus family groups to test the proposal that nepotistic parental tolerance gives the natal territory a special value for the offspring, which they cannot find elsewhere and that makes them stay. In this species, parents are more tolerant of their retained offspring than towards immigrant extra birds. In response to the removal of fathers, retained offspring dispersed, whereas there was no similar response among the unrelated extra birds. Retained offspring, however, left only after despotic immigrant alpha-males replaced removed fathers, indicating that the presence of fathers is an essential motive for offspring to delay their dispersal. By blocking immigrant and unrelated males from becoming alpha-males and by being tolerant themselves, fathers provide a 'safe haven' in the natal territory where retained offspring can avail themselves of available resources without any, or only mild, competitive interference.

Although it is known that, in the uterus, estrogen receptor alpha (ERalpha) is involved in proliferation and progesterone receptor in differentiation, the role of the two other gonadal-hormone receptors expressed in the uterus, androgen receptor (AR) and estrogen receptor beta (ERbeta), remains undefined. In this study, the involvement of AR in 17beta-estradiol (E(2))-induced cellular proliferation in the immature rat uterus was investigated. AR levels were low in the untreated immature uterus, but 24 h after treatment of rats with E(2), there was an increase in the levels of AR and of two androgen-regulated genes, IGF-I and Crisp (cysteine-rich secretory protein). As expected, E(2) induced proliferation of luminal epithelial cells. These actions of E(2) were all blocked by both the antiestrogen tamoxifen and the antiandrogen flutamide. The E(2)-induced AR was found by immunohistochemistry to be localized exclusively in the stroma, mainly in the myometrium, where it colocalized with ERalpha but not with ERbeta. ERbeta, detected with two different ERbeta-specific antibodies, was expressed in both stromal and epithelial cells either alone or together with ERalpha. Treatment with E(2) caused down-regulation of ERalpha and ERbeta in the epithelium. The data suggest that, in E(2)-induced epithelial cell proliferation, ERalpha induces stromal AR and AR amplifies the ERalpha signal by induction of IGF-I. Because AR is never expressed in cells with ERbeta, it is unlikely that ERbeta signaling is involved in this pathway. These results indicate an important role for AR in proliferation of the uterus, where estrogen and androgen do not represent separate pathways but are sequential steps in one pathway.

Kin-based cooperative breeding, where grown offspring delay natal dispersal and help their parents to rear new young, has a long history in some avian lineages. Family formation and helping behaviour in extant populations may therefore simply represent the retention of ancestral features, tolerated under current conditions, rather than a current adaptive process driven by environmental factors. Separating these two possibilities challenges evolutionary biologists because of the tight coupling that normally exists between phylogeny and the environmental distribution of species and populations. The carrion crow Corvus corone corone, which exhibits extreme interpopulational variation in the extent of cooperative breeding, with populations showing no delayed dispersal and helping at all, provides a unique opportunity for an experimental approach. Here we show that offspring of non-cooperative carrion crows from Switzerland will remain on the natal territory and express helping behaviour when raised in a cooperative population in Spain. When we transferred carrion crow eggs from Switzerland to Spain, five out of six transplanted juveniles delayed dispersal, and two of those became helpers in the following breeding season. Our results provide compelling experimental evidence of the causal relationship between current environmental conditions and expression of cooperative behaviour.

In this study three different types of samplers for the determination of 1,6-hexamethylene diisocyanate in air were compared. The experimental set up was a simulation of real life conditions with spray painting operations performed inside a commercial, full sized, spray box. The sampling methods were 1-(2-methoxyphenyl)-piperazine impregnated on glass fibre filter, and the same reagent in impinger, and also dibutylamine in impinger. All analyses were performed by LC-MS-MS. The determined concentrations varied between 20 and 90 microg m(-3) with relative standard deviations from 7 to 17% for each method. No significant difference was found between the three methods using ANOVA with a significance level of alpha = 0.05.

We present a dynamic programming model which is used to investigate hypothermia as an adaptive response by small passerine birds in winter. The model predicts that there is a threshold function of reserves during the night, below which it is optimal to enter hypothermia, and above which it is optimal to rest. This threshold function decreases during the night, with a particularly sharp drop at the end of the night, representing the time and energy costs associated with returning to normal body temperature. The results of the model emphasise the trade-off between energy and predation, not just between foraging options, but also between foraging during the day and entering hypothermia at night. The value of being able to use hypothermia represents not just energy savings, but also reduced predation risk due to changes in the optimal foraging strategy. Conditions which give a high value of hypothermia are short photoperiod, variable food supply, low temperatures, poor and scarce food supplies.

Dystroglycan is a member of the transmembrane dystrophin glycoprotein complex in muscle that binds to the synapse-organizing molecule agrin. Dystroglycan binding and AChR aggregation are mediated by two separate domains of agrin. To test whether dystroglycan plays a role in receptor aggregation at the neuromuscular junction, we overexpressed it by injecting rabbit dystroglycan RNA into one- or two-celled Xenopus embryos. We measured AChR aggregation in myotomes by labeling them with rhodamine-alpha-bungarotoxin followed by confocal microscopy and image analysis. Dystroglycan overexpression decreased AChR aggregation at the neuromuscular junction. This result is consistent with dystroglycan competition for agrin without signaling AChR aggregation. It also supports the hypothesis that dystroglycan is not the myotube-associated specificity component, (MASC) a putative coreceptor needed for agrin to activate muscle-specific kinase (MuSK) and signal AChR aggregation. Dystroglycan was distributed along the surface of muscle membranes, but was concentrated at the ends of myotomes, where AChRs normally aggregate at synapses. Overexpressed dystroglycan altered AChR aggregation in a rostral-caudal gradient, consistent with the sequential development of neuromuscular synapses along the embryo. Increasing concentrations of dystroglycan RNA did not further decrease AChR aggregation, but decreased embryo survival. Development often stopped during gastrulation, suggesting an essential, nonsynaptic role of dystroglycan during this early period of development., (Copyright 2000 Academic Press.)

The experimental optical interconnection module of the Free-Space Accelerator for Switching Terabit Networks (FAST-Net) project is described and characterized. Four two-dimensional (2-D) arrays of monolithically integrated vertical-cavity surface-emitting lasers (VCSEL's) and photodetectors (PD's) were designed, fabricated, and incorporated into a folded optical system that links a 10 cm x 10 cm multichip smart pixel plane to itself in a global point-to-point pattern. The optical system effects a fully connected network in which each chip is connected to all others with a multichannel bidirectional data path. VCSEL's and detectors are arranged in clusters on the chips with an interelement spacing of 140 microm. Calculations based on measurements of resolution and registration tolerances showed that the square 50-microm detector in a typical interchip link captures approximately 85% of incident light from its associated VCSEL. The measured optical transmission efficiency was 38%, with the losses primarily due to reflections at the surfaces of the multielement lenses, which were not antireflection coated for the VCSEL wavelength. The overall efficiency for this demonstration is therefore 32%. With the measured optical confinement, an optical system that is optimized for transmission at the VCSEL wavelength will achieve an overall efficiency of greater than 80%. These results suggest that, as high-density VCSEL-based smart pixel technology matures, the FAST-Net optical interconnection concept will provide a low-loss, compact, global interconnection approach for high bisection-bandwidth multiprocessor applications in switching, signal processing, and image processing.