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Purpose: This exploratory study sought to establish the psychometric stability of a dynamic norming system using the Systematic Analysis of Language Transcripts (SALT) databases. Dynamic norming is the process by which clinicians select a subset of the normative database sample matched to their individual client's demographic characteristics. Method: The English Conversation and Student-Selected Story (SSS) Narrative databases from SALT were used to conduct the analyses in two phases. Phase 1 was an exploratory examination of the standard error of measure (SEM) of six clinically relevant transcript metrics at predetermined sampling intervals to determine (a) whether the dynamic norming process resulted in samples with adequate stability and (b) the minimum sample size required for stable results. Phase 2 was confirmatory, as random samples were taken from the SALT databases to simulate clinical comparison samples. These samples were examined (a) for stability of SEM estimations and (b) to confirm the sample size findings from Phase 1. Results: Results of Phase 1 indicated that the SEMs for the six transcript metrics across both databases were low relative to each metric's scale. Samples as small as 40–50 children in the Conversation database and 20–30 children in the SSS Narrative database resulted in stable SEM estimations. Phase 2 confirmed these findings, indicating that age bands as small as ±4 months from a given center-point resulted in stable estimations provided there were approximately 35 children or more in the comparison sample. Conclusion: Psychometrically stable comparison samples can be achieved using SALT's dynamic norming system that are much smaller than the standard sample size recommended in most tests of children's language.

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele. © 2022. The Author(s).

We use Si MEMS cantilevers as sample carriers to gain high cycle fatigue data for thin metal films by accelerated stress testing. A typical number of 107 cycles can thus be achieved in a couple of hours. A closed loop control using laser beam deflection allows to keep the load on the thin film constant while in parallel its degradation is monitored continuously by recording resonance frequency, thin layer electrical resistance and surface roughness, the latter ex situ by AFM. We show a correlation between those three failure indicators and motivate a relationship with the failure parameter within a physics-of-failure based reliability paradigm. The proposed method opens an introspect view on the degradation behaviour of thin metal films as well as a rapid statement on their reliability under vibration loading at different temperatures. In this paper, the method is exemplified on the disruption of $1.2 \mu \mathrm{m}$ thin sputtered Aluminium layers.

Sintered silver (SAG) is a widely-used die attach (DA) technology in automotive industry, especially for power modules in electric vehicles (EV) defined by higher power densities. High operation temperatures (> 175°C) are particularly resulting from the application of dies based on wide bandgap semiconductors materials like SiC and GaN. The thermo-mechanical stress resulting from large temperature swings in EV applications fatigues the porous layer of SAG. In order to estimate the reliability of die attach layers physics-of-failure (PoF) based lifetime models are needed. In this study, comparative parametric simulations are used to estimate the influence of geometric factors on the lifetime of the die attach layer. In addition, the state of the art of accelerated fatigue experiments is presented.

Mastectomy is the standard procedure in patients with in-breast tumor recurrence (IBTR) or breast cancer after irradiation of the chest due to Hodgkin’s disease. In certain cases a second breast conserving surgery (BCS) in combination with intraoperative radiotherapy (IORT) is possible. To date, data concerning BCS in combination with IORT in pre-irradiated patients are limited. This is the first pooled analysis of this special indication with a mature follow-up of 5 years. Patients with IBTR after external beam radiotherapy (EBRT; treated in two centers) for breast cancer were included. Patients with previous EBRT including the breast tissue due to other diseases were also included. IORT was performed with the Intrabeam™-device using low kV X-rays. Clinical data including outcome for all patients and toxicity for a representative cohort (LENT-SOMA scales) were obtained. Statistical analyses were done including Kaplan–Meier estimates for local recurrence, distant metastasis and overall survival. A total of 41 patients were identified (39 patients with IBTR, 2 with Hodgkin`s disease in previous medical history). Median follow-up was 58 months (range 4–170). No grade 3/4 acute toxicity occurred within 9 weeks. Local recurrence-free survival rate was 89.9% and overall survival was 82.7% at 5 years. Seven patients developed metastasis within the whole follow-up. BCS in combination with IORT in IBTR in pre-irradiated patients is a feasible method to avoid mastectomy with a low risk of side effects and an excellent local control and good overall survival.

Integration of more functionality and smaller chips into decreasing package volume leads to increasing heat generation. In addition, the use of new compound semiconductors like SiC and GaN require a high thermal conductivity of the interconnect materials. One of the promising solutions is a layer of sintered silver between semiconductor and substrate. The advantages compared to conventional solders are significant. A higher thermal and electrical conductivity in combination with a higher duty temperature due to a higher melting point should enhance the reliability of the package. However, even as the large scale commercial usage of the material has been started by the industry recently, many important details of the mechanical properties and the reliability behavior are still unknown. While the thermal properties could be characterized relatively easy and are quite repeatable and stable, the mechanical properties - important for the reliability - are extremely process-dependent and wide-spreading. The hunt for lowest feasible sintering process parameters - such as temperature, time and especially pressure - even amplify that behavior and led to an impasse in some cases. Also their failure mechanisms, to be identified in lifetime investigations, are yet unknown as well as their stability and predictability. In order to enable prolonged function of these interfaces, thermo-mechanical reliability has to be assured. Within this paper, we show the status of silver sintering and the problems regarding mechanical material characterization found in literature. Additionally, we present a guideline for the mechanical acceleration of reliability experiments by isothermal bending tests. Finally a proof of concept by failure analysis will be presented.

Thermal greases allow a low stress bond at low bond line thicknesses (BLT) at medium thermal conductivities and simple application, all of which make it an alternative to solders, thermal adhesives or pads. It is widely used in power and microprocessor applications, most of which involve large areas to be used for heat transfer. However, for years thermal overload failure of power modules and chips has been a pressing problem due to pump-out of thermal grease as a die or module thermal interface material (TIM): Most thermal greases are Bingham fluids and thus not solids, so they can be squeezed out from in between the gap, driven by thermo-mechanical action of the adjacent layers as e.g. DCB substrate or silicon chip with the heat sink. Today, thermal greases have to be qualified in lengthy stress tests in a product relevant environment which consumes substantial resources as often a system test is required. Therefore, a fast test is necessary which accelerates testing and thus allows a fast screening of commercial greases on one hand, and guidelines for material development on the other. For that purpose this paper addresses this topic in a combined simulative and experimental way, where at the same time a novel test procedure is proposed for accelerated grease pump-out testing (GPOT) in the framework of a completely new approach, combining loading with in-situ failure analytical techniques and decoupling thermal from mechanical loading. This allows for the first time a realistic loading of greases during accelerated testing with testing times below one hour. The method is demonstrated on various commercial and custom greases, varying their composition and structure, and benchmarked against industry standard thermal cycling tests. Further, two fundamental failure mechanisms have been identified being at work simultaneously, notably fluid transport (which constitutes actually a pump-in phenomenon) and air entrapment. We were able to identify key properties of the materials and loading variables, on which their intensity depends.

In this paper we summarize extensive literature review on the fatigue of thin metal films. Additionally we describe our custom-made set-up for isothermal mechanical cycling of thin films on cantilever-like reflective substrates. The device is made for in-resonance testing in the frequency ranges from 10 Hz to 1000 Hz and allows detection of failure by shift in stiffness of the sample.

Novel concepts in power electronics rely heavily on the availability and processability of new materials and packaging technologies to meet the requirements of increasing performance and reliability at lower form factor, weight and cost. Today’s main technological route for converter modules is still the power die soldered and wire-bonded to a DCB substrate. New applications or semiconductor technologies like e.g. SiC, however, require enhanced thermal management using standard commercial casings within the same, usually very limited thermal budget. This paper is the final of a series of publications dealing with a novel thermal management concept for power electronics enabled by the use of advanced packaging technologies as well as smart handling of power transients, making use of a TEC and a thermal buffer using a low melting BiSn eutectic as phase change material to store excess heat temporarily exploiting the PCM’s enthalpy of fusion. This concept is exemplified on a typical six-pack converter module for industrial applications (4 kW, 1200 Volts) to be integrated into a standard easyPIM casing while being able to cope with overload power pulses. This paper summarises the whole system approach, references back to literature for details finishes the series of papers with the reliability analysis of the buffer technology. Thus, all stages of product development covering design, technology and performance are finally highlighted.

Thermal greases allow a low stress bond at low bond line thicknesses (BLT) at medium thermal conductivities and simple application, all of which make it an alternative to solders, thermal adhesives or pads. It is widely used in power and microprocessor applications, most of which involve large areas to be used for heat transfer. However, for years thermal overload failure of power modules and chips has been a pressing problem due to pump-out of thermal grease as die or module thermal interface material (TIM): Most thermal greases are Bingham fluids and thus not solids, so they can be squeezed out from in between the gap, driven by thermo-mechanical action of the adjacent layers as e.g. DCB substrate or silicon chip with the heat sink. Today, thermal greases have to be qualified in lengthy stress tests in a product relevant environment which consumes substantial resources as often a system test is required. Therefore, a fast test is necessary which accelerates testing and thus allows a fast screening of commercial greases on one hand, and guidelines for material development on the other. For that purpose this paper addresses this topic in a combined simulative and experimental way, where at the same time a novel test procedure is proposed for accelerated grease pump-out testing (GPOT) in the framework of a completely new approach, combining loading with in-situ failure analytical techniques and decoupling thermal from mechanical loading. This allows for the first time a realistic loading of greases during accelerated testing. The method is demonstrated on various commercial and custom greases, varying their composition and structure, and benchmarked against industry standard thermal cycling tests.

Thin metal layers, especially those made of copper, are omnipresent in today's packaging applications as e.g. RDL structures, conductor traces on flexible and stretchable substrates, chip finishes or terminal metallisation, serving electrical, thermal or mechanical purposes. During operation, thermo-mechanical stress will cause failures in the Cu layers and interfaces over time. As Cu is very process and size dependent, its resistance to fatigue failure needs to be characterised with samples which have undergone identical processing steps as those in the real application. For that purpose, simple specimens and fast testing routines are necessary, some of which may need special loading stages for varying the load variables of interest such as stress amplitude and temperature. This paper addresses fatigue characterisation of thin Cu films on silicon under typical processing conditions on simple and inexpensive but industry-grade samples. Along with them, custom built test stands have been used to handle those specimens appropriately within a specimen-centred approach.

Permanentmagnet-Bremsen als Haltebremsen mit Notstoppfunktion gehören heute aus guten Gründen zu den am meisten verbreiteten Sicherheitsbremsen in der Robotik und im Maschinenbau. Sie überzeugen durch höchste Drehmomente bezogen auf die Baugröße (Leistungsdichte), einen verschleiß- und restmomentfreien Betrieb, kurze Schaltzeiten und Verdrehspielfreiheit. Damit sind sie bestens geeignet für Servomotoren in den unterschiedlichsten Einsatzbereichen. Bei konventionellem Design der PM-Bremsen gibt es allerdings Grenzen bedingt durch das Wirkprinzip, was z. B. Spannungs- toleranzen oder Betriebstemperaturbereich anbelangt. Permanentmagnetbremsen in „High-Torque“- Technologie bieten hier Vorteile und sind deshalb für anspruchsvolle Anwendungen die richtige Wahl. Typische Beispiele dafür finden sich vor allem bei Outdoor-Anwendungen, z. B. in Windkraftanlagen oder im Sicherheitsbereich.

Thermal greases allow a low stress bond at low bond line thicknesses (BLT) at medium thermal conductivities and simple application, all of which make it an alternative to solders, thermal adhesives or pads. It is widely used in power and microprocessor applications, most of which involve large areas to be used for heat transfer. However, for years thermal overload failure of power modules and chips has been a pressing problem due to pump-out of thermal grease as die or module thermal interface material (TIM): Most thermal greases are Bingham fluids and thus no solids, so they can be squeezed out from in between the gap, driven by thermo-mechanical action of the adjacent layers as e.g. DCB substrate or silicon chip with the heat sink. Today, thermal greases have to be qualified in lengthy stress tests in a product relevant environment which consumes substantial resources as often a system test is required. Therefore, a fast test is necessary which accelerates testing and thus allows a fast screening of market-available greases on one hand, and guidelines for material development on the other. For that purpose this paper addresses this topic in a combined simulative and experimental manner, where at the same time a novel test procedure is proposed for accelerated grease pump-out testing (GPOT) in the framework of a completely new approach, combining loading with in-situ failure analytical techniques and decoupling thermal from mechanical loading.

In Saccharomyces cerevisiae , the vacuolar protein sorting complexes Vps51/52/53/54 and Vps15/30/34/38 are essential for efficient endosome-to-Golgi complex retrograde transport. Here we investigated the function of Vps15 and Vps51, representative members of these complexes, in the stress resistance, host cell interactions, and virulence of Candida albicans . We found that C. albicans vps15 Δ/Δ and vps51 Δ/Δ mutants had abnormal vacuolar morphology, impaired retrograde protein trafficking, and dramatically increased susceptibility to a variety of stressors. These mutants also had reduced capacity to invade and damage oral epithelial cells in vitro and attenuated virulence in the mouse model of oropharyngeal candidiasis. Proteomic analysis of the cell wall of the vps51 Δ/Δ mutant revealed increased levels of the Crh11 and Utr2 transglycosylases, which are targets of the calcineurin signaling pathway. The transcript levels of the calcineurin pathway members CHR11 , UTR2 , CRZ1 , CNA1 , and CNA2 were elevated in the vps15 Δ/Δ and vps51 Δ/Δ mutants. Furthermore, these strains were highly sensitive to the calcineurin-specific inhibitor FK506. Also, deletion of CHR11 and UTR2 further increased the stress susceptibility of these mutants. In contrast, overexpression of CRH11 and UTR2 partially rescued their defects in stress resistance, but not host cell interactions. Therefore, intact retrograde trafficking in C. albicans is essential for stress resistance, host cell interactions, and virulence. Aberrant retrograde trafficking stimulates the calcineurin signaling pathway, leading to the increased expression of Chr11 and Utr2, which enables C. albicans to withstand environmental stress.

Aluminium is still one of the most important contact metallisations for power electronic chips like MOSFETs or IGBTs. With a large difference in thermal expansion coefficients (CTEs) between aluminium and silicon and the temperatures generated in hot-spots during high power transients, these layers are prone to failure due to thermo-mechanical fatigue. Usually lifetime assessment is done by subjecting dedicated test specimens to standardised stress tests as e.g. active or passive thermal cycling. This paper proposes a novel method for accelerated stress testing and lifetime modelling of thin aluminium films in the high-cycle fatigue regime by isothermal mechanical loading. The proposed novel test method is suggested to complement or replace resource-demanding thermal cycling tests and allow simple in-situ monitoring of failure.

Lifetime (or health) monitoring in modern power electronics & luminaries continuously gains in importance, especially if safety-relevant applications are in the focus. Moreover, technology development of such devices requires fast and if possible continuous assessment of structural integrity. This work proposes a simplification of transient thermal testing (TTA) of LEDs by condensing measurement data analysis into one characteristic value to be stored and compared to successive or previous measurements for damage evaluation. Our custom-built in-situ monitoring system is based on microcontroller (uC) functionalities and can be used as stand-alone solution for reliability testing without any other electronic equipment. For quantitative assessment of measurement system performance we used Luxeon Z LEDs with different thermal interface materials. Pre-calibrated samples were inspected for structural integrity before and after cycling tests by X-Ray inspection. Measurement concept as detection for failure at thermal interface or die attach was qualitatively proven by correlation with structure function evaluation.

The authors consider two lattice gas models where dimers are placed on the simple cubic lattice with an attractive interaction between collinear dimers. They prove (using reflection positivity and Peierls' argument) that at low enough temperatures both models exist in an ordered state where one or two of the three orientations are preferred. No attempt is made at deciding whether the ordered state actually has dimers of two orientations or only of one orientation. Both models have earlier been considered in the two-dimensional version and proved to exhibit ordering at low temperature.

This paper presents a systematic study of sintered silver. In order to investigate the correlation between processing conditions, microstructures, thermal and electrical properties, sintered silver samples have been prepared in 27 variations of sintering temperature between 200°C and 270°C and sintering pressure between 5 MPa and 25 MPa. For the thermal and electrical characterization, the innovative test stand LaTIMA has been used. The microstructures of the samples have been analyzed by focused ion beam (FIB) and scanning electron microscope (SEM). The results of the thermal and electrical characterizations as well as the structure analysis showed clear correlation to the process conditions of sintered silver.

The cost and the package size driven size reduction of semiconductors lead to much higher heat generation. Also the use of new high power technologies on the basis of SiC produces is a need for high conductivity of the interconnect materials. Therefore the requirements for mechanical, thermal and electrical properties of interconnect materials increase compared to existing eutectic solder and glue materials. One of the promising solutions is a sintered layer between semiconductor and substrate. Especially from sintered layers one expects very high thermal conductivity and good mechanical properties in the package. Therefore, new materials with advanced behavior exploiting nano-effects have been developed in the last years. However, processes to use such materials as TIM-material for power applications are still to be optimized for e.g. zero pressure processing. So also their failure mechanisms, to be identified in lifetime investigations, are yet unknown as well as their stability. In order to enable prolonged function of these interfaces, thermo-mechanical reliability has to be assured. Dedicated fatigue tests have to be conducted to evaluate lifetime under relevant testing conditions, then failure mechanisms such as delamination or cracking have to be identified, understood and quantitatively condensed into a lifetime model to predict reliability for future designs. Within this paper, we present a guideline for the mechanical acceleration of reliability experiments for end-of-lifetime prognostics as well as the state of the art regarding reliability and mechanical characterization of sintered silver.

Aluminium is still one of the most important contact metallisations for power electronic chips like MOSFETs or IGBTs. With a large difference in thermal expansion coefficients (CTEs) between aluminium and silicon and the temperatures generated in hot-spots during high power transients, these layers are prone to failure due to thermo-mechanical fatigue. So far, lifetime modelling was done by subjecting dedicated test specimens to the thermal cycling one would expect during normal operation. This paper will propose a novel method for creating accelerated lifetime models of thin aluminium films within the high-cycle fatigue regime by isothermal mechanical loads. The specially designed test stand is suggested to complement or replace expensive and lengthy thermal cycling and allow in-situ monitoring of failure indicators.

The major fungal pathogen Candida albicans can occupy diverse microenvironments in its human host. During colonization of the gastrointestinal or urogenital tracts, mucosal surfaces, bloodstream, and internal organs, C. albicans thrives in niches that differ with respect to available nutrients and local environmental stresses. Although most studies are performed on glucose-grown cells, changes in carbon source dramatically affect cell wall architecture, stress responses, and drug resistance. We show that growth on the physiologically relevant carboxylic acid, lactate, has a significant impact on the C. albicans cell wall proteome and secretome. The regulation of cell wall structural proteins (e.g. Cht1, Phr1, Phr2, Pir1) correlated with extensive cell wall remodeling in lactate-grown cells and with their increased resistance to stresses and antifungal drugs, compared with glucose-grown cells. Moreover, changes in other proteins (e.g. Als2, Gca1, Phr1, Sap9) correlated with the increased adherence and biofilm formation of lactate-grown cells. We identified mating and pheromone-regulated proteins that were exclusive to lactate-grown cells (e.g. Op4, Pga31, Pry1, Scw4, Yps7) as well as mucosa-specific and other niche-specific factors such as Lip4, Pga4, Plb5, and Sap7. The analysis of the corresponding null mutants confirmed that many of these proteins contribute to C. albicans adherence, stress, and antifungal drug resistance. Therefore, the cell wall proteome and secretome display considerable plasticity in response to carbon source. This plasticity influences important fitness and virulence attributes known to modulate the behavior of C. albicans in different host microenvironments during infection.

SUMMARY The purpose of this study was to report the outcome of radio(chemo)therapy in the curative management of esophageal squamous cell carcinoma (ESCC). We retrospectively analyzed 163 patients with T1-T4, N0-1, M0 ESCC who were treated between January 1988 and December 2006 at the Technische Universitat Munchen. One hundred sixty patients were inoperable due to a poor performance status, comorbidities or locally advanced unresectable disease. External beam radiation therapy (EBRT) was performed with (n= 146) or without (n= 17) systemic chemotherapy. Fifty-four patients received an additional boost with intraluminal brachytherapy (IBT). Surviving patients were followed for a median of 72 months (range 10–173 months). The estimated overall survival (OS) at 2 and 5 years was 27 ± 4% and 11 ± 3%, respectively. Loco-regional recurrence at the primary site was observed in 29% of patients (n= 47). The recurrence-free survival (RFS) at 2 and 5 years was 24 ± 3% and 9 ± 2%, respectively. In multivariate analyses, the ECOG performance status (P= 0.004), 3D conformal (vs conventional) radiotherapy (P= 0.031) and continuous standard fractionation (vs split-course radiotherapy, P= 0.048) were associated with a better OS. Simultaneous chemotherapy (P= 0.49) or IBT (P= 0.31) had no significant impact on survival. Outcome for patients with ESCC is poor. Despite the very unfavorable patient selection (poor performance status, high rate of comorbidities, and advanced disease), long-term survival with radio(chemo)therapy was achieved in about 10% of patients. The introduction of modern treatment techniques/modalities (3D conformal planning/ continuous standard fractionation) might be associated with better outcomes.

Within this paper, we present a guideline for the mechanical acceleration of reliability experiments for end-of-lifetime prognostics of metal based die attach materials. First, we used an advanced hybrid nano-effect sintered silver layer as interface between die and substrate which has very good electrical and thermal conductivities. Two pairs ofexperiment/simulation are scheduled. An isothermal mechanical 3-pt bending experiment to induce fatigue the specimens rapidly as well as a thermal induced strain fatigue by thermal chamber for validation. The manufactured specimens are designed to be used for both. With a FEM of this subsystem to simulate the failure parameter which is the accumulated von Mises strain, lifetime modelling can be performed.

The generation of meaningful lifetime-models is a serious and time-consuming challenge throughout the field of packaging. Wherever different materials are joined, the CTE mismatch will usually lead to thermo-mechanical fatigue due to the temperature cycles during the usage of the system [1–3]. As a result, the fatigue of interconnections is the limiting factor for reliability of electronic systems [4]. Usually lifetime investigations are executed as active or passive thermal cycles using the final systems with fixed amplitudes. The main objective is rather the validation that the system will exceed a minimum threshold than the developing of a full lifetime-model. Detailed investigations are often bypassed due to time and financial limitations not realizing the future benefits of a lifetime-model, i.e. by gaining understanding of failure mechanisms and the possibility to predict them by modelling [5–9]. Especially for interfaces based on new developed and mostly insufficiently examined materials like sintered (porous) or composite with their predicted time-depending or highly anisotropic behavior, more detailed experiments are necessary to understand the physics of failure. Such results are required for the technology developing and optimization of fatigue behavior. Therefor more experiments with samples of different technology-parameters as well as different amplitudes or load-regimes are necessary to examine the stability of failure mechanisms and the damage accumulation. New concepts to conduct such lifetime investigations faster are urgently needed [5]. The idea presented in this paper is to show a suitable method to substitute lengthy thermal cycling tests by results obtained by rapid isothermal fatigue tests at different temperatures and how to establish a correlation between both of them. For now, samples based on galvanically deposited copper are used as common reference-material. Based on physics of failure principles, the applicability and viability of such a concept then is evaluated and discussed. In conclusion, this work shows a approach for a significant acceleration of the design for reliability procedure in system integration. It is based on the now possible rapid generation of a lifetime model by thin metal layer samples which are easily manufacturable with the same technology as the thermal cycling test (TCT) samples and should show the same failure mechanism. Detailed investigations are still needed to confirm an applicability of the method also to other metal layers used in the electronic packaging industry.

Heilmann, L. J., Nitzan, N., Johnson, D. A., Pasche, J. S., Doetkott, C., and Gudmestad, N. C. 2006. Genetic variability in the potato pathogen Colletotrichum coccodes as determined by amplified fragment length polymorphism and vegetative compatibility group analyses. Phytopathology 96:1097-1107. Amplified fragment length polymorphism (AFLP) using three primer sets was used to characterize 211 Colletotrichum coccodes isolates from North America, 112 of which were assigned to six vegetative compatibility groups (VCGs) using nitrate nonutilizing (nit) mutants. These isolates clustered into five corresponding groups by unweighted pairgroup method with arithmetic means-based cluster analysis of AFLP banding patterns. Isolates of C. coccodes belonging to NA-VCG1 and NA-VCG3 were closely related, as were isolates belonging to NA-VCG2 and NA-VCG5. Based on bootstrap analysis of AFLP data, the two isolates originally assigned to NA-VCG4 clustered with isolates belonging to NA-VCG2 and NA-VCG5. C. coccodes isolates that clustered with two isolates belonging to NA-VCG6 were the most diverged from other groups, including seven isolates collected from hosts other than potato. As opposed to the bootstrap analysis, a quadratic discriminant analysis (QDA) of AFLP data correctly categorized the two isolates of NA-VCG4. Furthermore, in isolates where VCG determinations had been made, this model correctly classified isolates of all VCGs. QDA classifications were identical to those made by the bootstrap analysis, with the exception of VCG4. Overall, classifications made by the QDA model were strongly correlated (r = 0.970, P < 0.001) to the VCGs assigned by traditional methods. All 99 C. coccodes isolates evaluated only by AFLP also were subjected to QDA, leading to the assignment of a presumptive VCG for each isolate. No isolates of VCG4 or VCG6 were identified by QDA within this population. Symptoms of black dot developed in plants inoculated with isolates collected from both potato and non-potato hosts. However, total yield was not significantly reduced by infection with non-potato isolates. The lack of any additional groups identified by AFLP analysis may be an indicator of a limited level of genetic variation among North American C. coccodes isolates. AFLP is a much more efficient technique for subspecific characterization in C. coccodes than VCG analysis utilizing nit mutants and will provide an effective means by which the population biology of this pathogen can be further investigated worldwide.

An one dimensional model for an open system with two kinds of particles which are driven in opposite directions by an external field is suggested. An exact solution for a steady state is given for the low density regime and it is shown that the model possesses what might be considered a phase transition from a gaseous to a liquid state. The relation to models with a fixed number of particles on a ring is discussed.

A total of 44 lipophilic and hydrophilic extracts obtained from 22 samples of cultured terrestrial and freshwater cyanobacteria were investigated for their biological activities. Of these, 54.5% of all extracts showed activity against Grampositive bacteria while 9.1% possessed antifungal activity against Candida albicans. No extract was active against Gram-negative bacteria. Two extracts exhibited significant activity against brine shrimp (Artemia salina). Cytotoxic activity against KB cells was demonstrated for 38.6% of the extracts. Of the 22 cyanobacteria investigated, 19 were active in at least one of the assays used. These results prove that terrestrial and freshwater cyanobacteria are still a promising source of new bioactive natural products.

This paper proposes a guideline for the mechanical acceleration of end-of-lifetime prognostics of metal based die attach materials. As a such, we used first an advanced nano-effect sintered silver layer as interface between die and substrate which has very god electrical and thermal conductivities. Two pairs of experiment/simulation are scheduled. An isothermal mechanical 3-pt bending experiment to induce fatigue the specimens rapidly as well as a thermal induced strain fatigue by thermal chamber for validation. The manufactured specimens are designed to be used for both. With a FEM of this subsystem to simulate the failure parameter which is the accumulated von Mises strain, lifetime modelling is possible.

Language sampling, recognized as a gold standard for expressive language assessment, is often elicited using wordless picture storybooks. A series of wordless storybooks, commonly referred to as 'Frog' stories, have been frequently used in language-based research with children from around the globe.To examine the impact that differences in stories have on narrative output by comparing narrative productions across a series of five storybooks produced by 831 bilingual (Spanish-English) children in kindergarten through third grade.Each participant produced oral narratives using one of the five Frog storybooks in both English and Spanish. The narratives were recorded, transcribed and coded for a variety of measures of language production.Negligible differences were observed in language measures when comparing groups of children who told different stories, with the exception of lexical diversity.The implications of using different storybooks to elicit narrative language samples from children are discussed from the perspectives of research and clinical practice.

We assume the rate constants of Smoluchowski's coagulation equation to be of the form, Ki,j = a(i). a(j)/[a(i)+a(j)-a(i+j)]. If a(i)/i>K>0 for all i then the model will have gelation (provided the solution exists). If a(i)/i0 as i it is then suggested that the model will not have gelation.

It is proven that the diagonal version of Smoluchowski's coagulation equation has a unique behaviour for large times, independent of the initial condition. Roughly speaking, the concentration then goes to zero as , where is a constant which depends only on the size of the polymer (and the rate constants). If the rate constants increase sufficiently fast with molecular size, then the total number of monomer units in solution also goes to zero as 1/t.