bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of high-operating-temperature InAs∕GaAs quantum-dot infrared detectors
Authors: Pal D. , Towe E.
Published: April 2006

Characteristics of high-operating-temperature InAs∕GaAs quantum-dot infrared detectors with a wide band gap current-blocking layer are reported. Clean photoresponse spectra were observed up to 220K. A high peak responsivity of about 4.3A∕W was measured at 100K; this responsivity decreased to 34mA∕W at 220K. The typical corresponding detectivity for the devices at 100K was ∼2×109cmHz1∕2∕W. This detectivity can be improved by increasing the areal quantum-dot density and by carefully optimizing the dopant impurity concentration in the device.
New possibilities for the measurement of wavelength-resolved photoconductivity
Authors: Montenegro Renata , Inocente-Junior Nilson R. , Frejlich Jaime
Published: April 2006

We report a new setup for the measurement of photoconductivity that is based on discrete quasimonochromatic light-emitting diodes. This setup allows new possibilities combining preexposure and measurement at different wavelengths as well as the possibility of rapidly switching from one wavelength to any other at will and also varying the irradiance over a comparatively wide range. It is also easy to use an equalized photonic flux over the entire operating wavelength range. We show the interest of using a normalized photoconductivity coefficient that takes into account the distribution of light in the sample’s volume and characterizes the specific properties of the material. We report typical results obtained in different conditions for the same undoped Bi12TiO20 photorefractive crystal.
Improving the thermal conductivity of nanocomposites by increasing the length efficiency of loading carbon nanotubes
Authors: Song P. C. , Liu C. H. , Fan S. S.
Published: April 2006

Since long and slender carbon nanotubes (CNTs) are usually self-entangled, we propose a factor, length efficiency, in this study to analyze the thermal conductivity of nanocomposites with CNT loading. Theoretical analysis reveals that an appropriate length distribution of CNTs could improve their length efficiency and more effectively enhance the thermal conductivity of the composites. This theory was supported by the experimental results of glycerin or silicone composites with modified CNT loading. Results also indicated that when length efficiency was taken into account, interfacial resistance effect would be less serious.
Genome evolution of wild cereal diversity and prospects for crop improvement
Authors: Nevo Eviatar
Published: April 2006

Genomic and proteomic diversity provide the basis of evolutionary change by natural selection under abiotic and biotic stresses, and the human-driven evolutionary process of domestication by artificial selection. Described here are some of the regional and local genomic and proteomic long-term multidisciplinary studies conducted at the Institute of Evolution, University of Haifa, Israel, during 1975–2005 (see publications athttp://evolution.haifa.ac.il), involving both wild barley,Hordeum spontaneum, the progenitor of cultivated barley and wild emmer sheat,Triticum dicoccoides, the progenitor of modern tetraploid and hexaploid cultivated wheat. Wild cereals harbour large amounts of as yet untapped adaptive genetic resources for crop improvement (resistances against abiotic and biotic stresses, micronutrient metal deficiencies, storage proteins, amylases and photosynthetic yield, among others). The adaptive genomic diversity of wild cereals, including cryptic beneficial alleles at specific quantitative trait loci ofT. dicoccoidesandH. spontaneumis the best genomic resource to be conservedin situandex situfor utilization by classical and modern biotechnologies, to enrich the genetically impoverished and stress-vulnerable food cultivars, advance crop improvement, and thereby increase and optimize world food production in a second genetic green revolution.
DNA banks and their role in facilitating the application of genomics to plant germplasm
Authors: Rice Nicole , Cordeiro Giovanni , Shepherd Mervyn , Bundock Peter , Bradbury Louis , Pacey-Miller Toni , Furtado Agnelo , Henry Robert
Published: April 2006

Advances in genomics have provided technologies for high throughput analysis of plant genomes with potential for use in gene discovery in germplasm collections. The establishment of DNA banks facilitates this screening by making DNA from large numbers of plant accessions widely available. DNA banks require the development of appropriate policies for access and benefit sharing. Tools for automating sample and data handling are essential. Standard molecular methods for fingerprinting DNA accessions for international comparisons need to be determined. New screening technologies are required to take advantage of the emerging availability of large DNA collections. The Australian Plant DNA Bank aims to collect DNA from all Australian plant species and to sample the diversity within each species. DNA from all individuals of the species is being stored for rare species. Domesticated or economically important species from all countries are also being collected and stored. International networking of DNA banks will be a key step in linking genomics tools to global plant diversity.
Impact of plant breeding on genetic diversity of agricultural crops: searching for molecular evidence
Authors: Fu Yong-Bi
Published: April 2006

There is a long-standing concern that modern plant breeding reduces crop genetic diversity, which may have consequences for the vulnerability of crops to changes in pests, diseases, climate and agricultural practices. Recent molecular assessments of genetic diversity changes in existing genepools of major agricultural crops may shed some light on the impact of plant breeding on crop genetic diversity. Reviewing published assessments revealed different impacts of plant breeding on improved genepools, not only narrowing or widening their genetic base, but also shifting their genetic background. In general, the genome-wide reduction of crop genetic diversity accompanying genetic improvement over time is minor, but allelic reduction at individual chromosomal segments is substantial. More efforts are needed to assess what proportion of lost alleles is associated with undesirable traits.
A panel of elite accessions of durum wheat (Triticum durumDesf.) suitable for association mapping studies
Authors: Maccaferri Marco , Sanguineti Maria Corinna , Natoli Vincenzo , Ortega José Luis Araus , Salem Moncef Ben , Bort Jordi , Chenenaoui Cynda , De Ambrogio Enzo , del Moral Luis Garcia , De Montis Andrea , El-Ahmed Ahmed , Maalouf Fouad , Machlab Hassan , Moragues Mark , Motawaj Jihan , Nachit Miloudi , Nserallah Nasserlehaq , Ouabbou Hassan , Royo Conxita , Tuberosa Roberto
Published: April 2006

The effectiveness of association mapping (AM) based on linkage disequilibrium (LD) is currently being tested in a number of crops. An important prerequisite for the application of AM is the availability of collections of accessions with a suitable level of genetic variation for target traits and with limited spurious LD due to the presence of population structure. Herein, the results of a genome-wide molecular characterization of a collection of elite durum wheat accessions well-adapted to Mediterranean environments are presented. Ninety-seven highly polymorphic simple sequence repeats and 166 amplified fragment length polymorphism markers were used to characterize 189 durum accessions, mainly cultivars and advanced breeding lines. Genome-wide significant and sizeable LD indices at a centimorgan scale were observed, while LD mainly decayed within 10 cM. On the other hand, effects due to spurious LD were notably lower than those previously observed in a durum wheat collection sampling durum gene pools of more diverse origin. These results, coupled with the high level of genetic variability detected for a number of important morpho-physiological traits and their high heritability, indicate the suitability of this collection for AM studies targeting agronomically important traits.
The processing of lexical stress during visual word recognition: Typicality effects and orthographic correlates
Authors: Arciuli Joanne , Cupples Linda
Published: April 2006

Many studies that have examined reading at the single-word level have been restricted to the processing of monosyllabic stimuli, and, as a result, lexical stress has not been widely investigated. In the experiments reported here, we used disyllabic words and nonwords to investigate the processing of lexical stress during visual word recognition. In Experiments 1 and 2, we found an effect of stress typicality in naming and lexical decision. Typically stressed words (trochaic nouns and iambic verbs) elicited fewer errors than atypically stressed words (iambic nouns and trochaic verbs). In Experiment 3, we carried out an analysis of 340 word endings and found clear orthographic correlates of both grammatical category and lexical stress in word endings. In Experiment 4, we demonstrated that readers are sensitive to these cues in their processing of nonwords during two tasks: sentence construction and stress assignment. We discuss the implications of these findings with regard to psycholinguistic models of single-word reading.
Survival time and period of catheterization in patients treated with percutaneous nephrostomy for urinary obstruction due to malignancy
Authors: Radecka E. , Magnusson M. , Magnusson A.
Published: April 2006

Purpose: To assess patient mortality and survival time, period of catheterization, and indications for percutaneous nephrostomy (PCN) withdrawal in patients treated with PCN for urinary obstruction due to malignancy.

Material and Methods: A retrospective analysis of 151 patients treated with 257 PCNs in a 5-year period was performed. Data on survival time, duration of catheterization, and clinical end-points for PCN treatment were collected.

Results: The median survival time of the patients was 255 days, while median catheterization time was 62 days. The majority of patients (84) died with the catheter. Indications for PCN withdrawal were surgery, stent treatment, catheter displacement, and response to medical treatment.

Conclusion: The majority of patients with malignancy treated with PCN have advanced disease and short life expectancy. Factors such as diagnosis, prognosis, economy, and the patient's preference influence the choice of urinary diversion method. However, PCN should be considered in patients with malignancy on grounds of safety and low cost.
Glioma assessment using quantitative blood volume maps generated by T1-weighted dynamic contrast-enhanced magnetic resonance imaging: a receiver operating characteristic study
Authors: Lüdemann L. , Grieger W. , Wurm R. , Wust P. , Zimmer C.
Published: April 2006

Purpose: To investigate the use of blood volume maps in the non-invasive separation of glioma grades.

Material and Methods: T1-weighted quantitative dynamic contrast-enhanced magnetic resonance imaging was used to quantify the fractional intratumoral blood volume of 41 gliomas (World Health Organization (WHO) grades II–IV). Two methods, mean fractional intratumoral blood volume determination and a system based on thresholds for extracting the tumor pixels with the highest vascularization from the blood volume maps, were investigated by means of receiver operating characteristic (ROC) analysis. The thresholds were adjusted using the ROC curve area calculated using the trapezoid method.

Results: The ability to separate grade II (WHO) gliomas from grades III–IV was nearly the same for both methods (ROC curve area 0.941 (threshold) versus 0.932 (mean value)) and significantly greater than the ability to separate grade IV (WHO) gliomas from grades II–III (ROC curve area 0.792 (threshold) versus 0.787 (mean value)). The best correspondence with WHO glioma grading was achieved using thresholds corresponding to only the 5.2% of tumor voxels with the largest blood volume for separating grade II gliomas and 4% for separating grade IV gliomas.

Conclusion: Use of the optimized threshold resulted in matching with the WHO grading system in 74% of cases.
Transcatheter arterial embolization in patients with bleeding duodenal ulcer: an alternative to surgery
Authors: Bendix Holme J. , Tønner Nielsen D. , Funch-Jensen P. , Viborg Mortensen F.
Published: April 2006

Purpose: To evaluate the efficacy and safety of transcatheter arterial embolization (TAE) in patients with bleeding/rebleeding duodenal ulcers.

Material and Methods: Over a 6-year-period, 40 consecutive patients with bleeding/rebleeding after endoscopic therapy and/or surgery for duodenal ulcer were included in the study. Superselective angiographic catheterization and coil embolization were performed by the same interventional radiologist.

Results: Lasting hemostasis was achieved in 26 of 40 patients (65%). Transfusion requirement was reduced from median 14 (range 3–35) units of blood before TAE to 2 (range 0–53) units after TAE. Ten patients died, five because of continuous bleeding. No adverse effects as a result of TAE were seen.

Conclusion: TAE is an effective and safe treatment in a significant proportion of patients with bleeding duodenal/rebleeding ulcers after therapeutic endoscopy and/or surgery.
Multidetector computed tomography and neuroendocrine pancreaticoduodenal tumors
Authors: Rappeport E. D. , Palnaes Hansen C. , Kjaer A. , Knigge U.
Published: April 2006

Purpose: To investigate the accuracy of dedicated pancreatic multidetector computed tomography (MDCT) in the diagnosis of neuroendocrine pancreaticoduodenal tumors (NPTs).

Material and Methods: MDCT and other imaging studies in patients with suspected NPTs were identified. Thirty dedicated MDCT studies were done in 23 patients. Fourteen patients (16 operations) subsequently had surgery. Imaging reports were reviewed and findings compared with surgical findings and findings in other imaging studies.

Results: Patients with surgery: 19 NPTs (16 extrapancreatic gastrinomas and 3 pancreatic NPTs) were identified at surgery. MDCT identified 16 and somatostatin receptor scintigraphy (SRS) 11 out of 19 tumors. Endoscopic ultrasound detected 11 out of 14 NPTs. Patients without surgery: In 4 out of 9 patients, no NPTs were identified at MDCT.

Conclusion: Dedicated MDCT of the pancreas can identify many NPTs, including small duodenal and periduodenal tumors, and the detection rate is better than reported in the older literature on CT.
Indications of inflammation visualized by ultrasound in osteoarthritis of the knee
Authors: Kristoffersen H. , Torp-Pedersen S. , Terslev L. , Qvistgaard E. , Cato Holm C. , Ellegaard K. , Bliddal H.
Published: April 2006

Purpose: Ultrasound examination of a group of patients with osteoarthritis (OA) of the knee for signs of inflammation.

Material and Methods: 71 knees in 71 patients with osteoarthritis of the knee were examined with high-resolution gray-scale ultrasound combined with color and spectral Doppler. The medial, lateral, and antero-superior compartments were examined. Hyperemia was identified as presence of color Doppler signals in the synovial membrane. Low resistance flow was defined as a resistive index <0.80 on spectral Doppler.

Results: Synovial thickening was found in all knees; fluid in 61 patients; and hyperemia (color Doppler activity) in 51 patients. Of these, 44 had arterial flow on spectral Doppler – 36 with a low resistance flow. When present, fluid and color Doppler activity was found in all three compartments, but with uneven distribution.

Conclusion: The finding in the majority of cases of both effusions on B-mode US and Doppler activity confirms that there is a varying degree of inflammation in knee OA as diagnosed by the ACR criteria.
Priming and trial spacing in extinction: Effects on extinction performance, spontaneous recovery, and reinstatement in appetitive conditioning
Authors: Moody Erik W. , Sunsay Ceyhun , Bouton Mark E.
Published: April 2006

Previous research in this laboratory suggests that priming of the conditional stimulus (CS) in short-term memory may play a role in the trial-spacing effects in appetitive conditioning. For example, a nonreinforced presentation of a CS 60 s before a reinforced trial with the same CS produced slower acquisition than a CS presentation that occurred 240 s before the reinforced trial. The results were consistent with the self-generated priming mechanism proposed by Wagner (e.g., Wagner 1978, 1981). The present experiments extended the earlier work by examining the effects of trial spacing in extinction rather than acquisition. After conditioning with a mixture of intertrial intervals (ITIs), rats received extinction with ITIs of 60 or 240 s, longer or shorter values, or different ways of “chunking” extinction trials in time. Although trial spacing produced effects on extinction performance that were consistent with our previous research on acquisition, there were few long-term differences in spontaneous recovery or in reinstatement. Short ITIs in extinction appear to affect extinction performance more than they affect extinction learning. Mechanisms of trial spacing in conditioning and extinction are discussed.
A dynamic ubiquitin equilibrium couples proteasomal activity to chromatin remodeling
Authors: Dantuma Nico P. , Groothuis Tom A.M. , Salomons Florian A. , Neefjes Jacques
Published: April 2006

Protein degradation, chromatin remodeling, and membrane trafficking are critically regulated by ubiquitylation. The presence of several coexisting ubiquitin-dependent processes, each of crucial importance to the cell, is remarkable. This brings up questions on how the usage of this versatile regulator is negotiated between the different cellular processes. During proteotoxic stress, the accumulation of ubiquitylated substrates coincides with the depletion of ubiquitylated histone H2A and chromatin remodeling. We show that this redistribution of ubiquitin during proteotoxic stress is a direct consequence of competition for the limited pool of free ubiquitin. Thus, the ubiquitin cycle couples various ubiquitin-dependent processes because of a rate-limiting pool of free ubiquitin. We propose that this ubiquitin equilibrium may allow cells to sense proteotoxic stress in a genome-wide fashion.
Cytotoxic T lymphocyte–induced killing in the absence of granzymes A and B is unique and distinct from both apoptosis and perforin-dependent lysis
Authors: Waterhouse Nigel J. , Sutton Vivien R. , Sedelies Karin A , Ciccone Annette , Jenkins Misty , Turner Stephen J. , Bird Phillip I. , Trapani Joseph A.
Published: April 2006

Cytotoxic T lymphocyte (CTL)–induced death triggered by the granule exocytosis pathway involves the perforin-dependent delivery of granzymes to the target cell. Gene targeting has shown that perforin is essential for this process; however, CTL deficient in the key granzymes A and B maintain the ability to kill their targets by granule exocytosis. It is not clear how granzyme AB−/− CTLs kill their targets, although it has been proposed that this occurs through perforin-induced lysis. We found that purified granzyme B or CTLs from wild-type mice induced classic apoptotic cell death. Perforin-induced lysis was far more rapid and involved the formation of large plasma membrane protrusions. Cell death induced by granzyme AB−/− CTLs shared similar kinetics and morphological characteristics to apoptosis but followed a distinct series of molecular events. Therefore, CTLs from granzyme AB−/− mice induce target cell death by a unique mechanism that is distinct from both perforin lysis and apoptosis.
Occurrence of Co-colonization or Co-Infection with Vancomycin-Resistant Enterococci and Methicillin-ResistantStaphylococcus aureusin a Medical Intensive Care Unit
Authors: Warren David K. , Nitin Anand , Hill Cheri , Fraser Victoria J. , Kollef Marin H.
Published: April 2006

Objective:

To determine the occurrence of co-colonization or co-infection with VRE and MRSA among medical patients requiring intensive care.

Design:

Prospective, single-center, observational study.

Setting:

A 19-bed medical ICU in an urban teaching hospital.

Patients:

Adult patients requiring at least 48 hours of intensive care and having at least one culture performed for microbiologie evaluation.

Results:

Eight hundred seventy-eight consecutive patients were evaluated. Of these patients, 402 (45.8%) did not have microbiologie evidence of colonization or infection with either VRE or MRSA 355 (40.4%) were colonized or infected with VRE, 38 (4.3%) were colonized or infected with MRSA, and 83 (9.5%) had co-colonization or co-infection with VRE and MRSA. Multiple logistic regression analysis demonstrated that increasing age, hospitalization during the preceding 6 months, and admission to a long-term-care facility were independently associated with colonization or infection due to VRE and co-colonization or co-infection with VRE and MRSA. The distributions of positive culture sites for VRE (stool, 86.7%; blood, 6.5%; urine, 4.8%; soft tissue or wound, 2.0%) and for MRSA (respiratory secretions, 34.1%; blood, 32.6%; urine, 17.1%; soft tissue or wound, 16.2%) were statistically different (P< .001).

Conclusions:

Co-colonization or co-infection with VRE and MRSA is common among medical patients requiring intensive care. The recent emergence of vancomycin-resistantStaphylococcus aureusand the presence of a patient population co-colonized or co-infected with VRE and MRSA support the need for aggressive infection control measures in the ICU.
Carriage of Methicillin-ResistantStaphylococcus aureusAmong Hospital Employees: Prevalence, Duration, and Transmission to Households
Authors: Eveillard Matthieu , Martin Yolaine , Hidri Nadia , Boussougant Yves , Joly-Guillou Marie-Laure
Published: April 2006

Objective:

To assess the prevalence and duration of methicillin-resistantStaphylococcus aureus(MRSA) carriage among hospital employees and transmission to their households.

Design:

A point-prevalence survey of MRSA carriage (nasal swabbing) of staff and patients throughout the hospital; a prevalence survey of MRSA carriage in 2 medical wards, with carriers observed to estimate carriage duration; and evaluation of transmission to MRSA-positive workers' families. All MRSA isolates were analyzed by pulsed-field gel electrophoresis. During the study, no MRSA outbreak was detected among hospitalized patients.

Setting:

A 600-bed, public tertiary-care teaching hospital near Paris.

Results:

Sixty MRSA carriers were identified among 965 healthcare providers (prevalence, 6.2%; CL,, 4.7%-7.7%). Prevalence was higher in staff from clinical wards than from elsewhere (9.0% vs 2.1%;P< .0001). Identity of isolates from employees and patients varied from 25% in medical wards to 100% in the long-term-care facility. MRSA carriage was identified in 14 employees from 2 medical wards (prevalence, 19.4%; CI95, 10.3%-28.5%). Prevalence depended on the length of service in these wards. Transmission to households was investigated in 10 MRSA-positive workers' families and was found in 4. All isolates from each family were identical.

Conclusions:

Few data are available concerning the prevalence of MRSA carriers among hospital employees in the absence of an outbreak among patients. MRSA transmission between patients and employees likely depends on the frequency and duration of exposure to MRSA-positive patients and infection control measures employed. Frequent transmission of MRSA from colonized healthcare workers to their households was documented.
A Longitudinal Analysis of Methicillin-ResistantStaphylococcus aureusin a Hong Kong Teaching Hospital
Authors: Ip Margaret , Lyon D. J. , Chio F. , Cheng A. F.
Published: April 2006

Objectives:

To review the incidence and trends of MRSA during a 12-year (1989-2000) period at a university teaching hospital and the relationship between strain distribution by antibiogram and molecular typing.

Design:

Retrospective review of laboratory-based surveillance records on MRSA isolation and characterization of strains by antimicrobial susceptibility and PFGE. A patient episode was counted at the time when MRSA was first isolated.

Setting:

A 1,350-bed university teaching hospital in Hong Kong.

Patients:

Those with clinical isolates of MRSA.

Results:

During 1989 to 2000, the hospital recorded 1,203,175 deaths and discharges (D&D) and encountered 5,707 patient episodes of new MRSA isolation. The overall incidence of patient episodes of MRSA was 0.47/100 D&D. In 1989, the incidence was 0.81/100 D&D and fell to a low of 0.33/100 D&D in 1995, but then rose to 0.50/100 D&D in 2000. Antibiogram and DNA typing identified 5 major types. PFGE type A constituted 68% (211/312) of isolates and was present throughout the 12-year period. PFGE type B constituted 13% (40/312) of isolates and was only present from 1995 to 2000. These isolates form a distinct clone and had unique antibiotic resistance profiles.

Conclusions:

The study showed the establishment of a dominant MRSA clone (PFGE type A group) in the intensive care, medical, and surgical units and the appearance of a new MRSA strain in 1995 (PFGE type B), which partly explained the rise in incidence of MRSA cases and a disproportionate rise in MRSA bacteremia from 1995 to 2000.
Health System Preparedness for Bioterrorism: Bringing the Tabletop to the Hospital
Authors: Henning Kelly J. , Brennan Patrick J. , Hoegg Cindy , O'Rourke Eileen , Dyer Bernard D. , Grace Thomas L.
Published: April 2006

Objective:

To evaluate the acceptance and usefulness of a hospital-based tabletop bioterrorism exercise.

Design:

A descriptive study of responses to a smallpox scenario delivered as a tabletop exercise in three modules.

Setting:

A large, multi-institutional urban health System.

Participants:

Healthcare workers representing 16 hospital departments.

Results:

Thirty-nine (78%) of 50 invited employees from 4 hospitals participated. Key responses highlighted the importance of pre-event planning in intra-departmental communication, identification of resources for the dependents of health-care workers, clarification of the chain of command within the hospital, establishment of a link to key governmental agencies, and advanced identification of negative pressure rooms for cohorting large numbers of patients. Almost one-fourth of the participants described their hospital departaient as poorly prepared for a bioterrorism event of moderate size. At the conclusion of the tabletop, 79% of the participants stated that the exercise had increased their knowledge of preplanning activities. Seventy-nine percent of all participants, 94% of physicians and nurses, and 95% of participants from non-university hospitals ranked the exercise as extremely or very useful. The exercise was completed in 3% hours and its total direct cost (excluding lost time from work) was $225 (U.S.).

Conclusions:

Tabletop exercises are a feasible, well-accepted modality for hospital bioterrorism preparedness training. Hospital employees, including physicians and nurses, rank this method as highly useful for guiding preplanning activities. Infection control staff and hospital epidemiologists should play a lead role in hospital preparedness activities. Further assessment of the optimal duration, type, and frequency of tabletop exercises is needed.
Acquisition of Nosocomial Pathogens on Hands After Contact With Environmental Surfaces Near Hospitalized Patients
Authors: Bhalla Anita , Pultz Nicole J. , Gries Delores M. , Ray Amy J. , Eckstein Elizabeth C. , Aron David C. , Donskey Curtis J.
Published: April 2006

We examined the frequency of acquisition of bacterial pathogens on investigators' hands after contacting environmental surfaces near hospitalized patients. Hand imprint cultures were positive for one or more pathogens after contacting surfaces near 34 (53%) of 64 study patients, withStaphylococcus aureusand vancomycin-resistantEnterococcusbeing the most common isolates.
Descriptive Analysis of Patients With Community-Onset and Hospital-Onset Methicillin- Resistant Staphylococcus aureus Infections
Authors: Rosario-Rosado Rosa V. , René Antonio A. , Jones Bobby
Published: April 2006

Three hundred sixty-seven hospital- and community-onset methicillin-resistant Staphylococcus aureus (MRSA) infections diagnosed in a Dallas-Fort Worth Metroplex community hospital are described. Differences in age, gender, ethnicity, and susceptibility to four antibiotics between the two groups of patients are explored.
Facility-Level Correlates of Antimicrobial Use in Nursing Homes
Authors: Loeb Mark , McGeer Allison , Simor Andrew , Walter Stephen D. , Bradley Suzanne , Low Donald E. , Moss Lorraine
Published: April 2006

We assessed the contribution of facility-Ievel variables to antimicrobial use in a cohort of 50 nursing homes and found that antimicrobial use was significantly correlated with the percentage of nursing home residents with feeding tubes, the number of healthcare aides, and the country of origin of the facility.
MEKHLA, a Novel Domain with Similarity to PAS Domains, Is Fused to Plant Homeodomain-Leucine Zipper III Proteins
Authors: Mukherjee Krishanu , Bürglin Thomas R.
Published: April 2006

Homeodomain (HD) proteins play important roles in the development of plants, fungi, and animals. Here we identify a novel domain, MEKHLA, in the C terminus of HD-Leu zipper (HD-ZIP) III plant HD proteins that shares similarity with a group of bacterial proteins and a protein from the green alga Chlamydomonas reinhardtii. The group of bacterial MEKHLA proteins is found in cyanobacteria and other bacteria often found associated with plants. Phylogenetic analysis suggests that a MEKHLA protein transferred, possibly from a cyanobacterium or an early chloroplast, into the nuclear genome of an early plant in a first step, and attached itself to the C terminus of an HD-ZIP IV homeobox gene in a second step. Further position-specific iterated-BLAST searches with the bacterial MEKHLA proteins revealed a subregion within the MEKHLA domain that shares significant similarity with the PAS domain. The PAS domain is a sensory module found in many proteins through all kingdoms of life. It is involved in light, oxygen, and redox potential sensation. The fact that HD-ZIP III proteins are transcription factors that have this sensory domain attached to their C terminus uncovers a potential new signaling pathway in plants.
Effects of preservation on pigmentation and length measurements in larval lampreys
Authors: Neave F. B. , Mandrak N. E. , Docker M. F. , Noakes D. L.
Published: April 2006

The effects of two methods of preservation (fixation and storage in 10% formalin, and fixation in 10% formalin followed by storage in 95% alcohol) on pigmentation and morphometric features used for identification of larval Ichthyomyzon lampreys were analysed. Both short‐term (3 weeks) and long‐term (6 months) studies were conducted using digital analysis of images of fresh and preserved lampreys. Six standard morphometric lengths and 10 areas of pigmentation were analysed. All measurements were significantly affected by preservation. Preservative type affected pigmentation and morphometric characteristics differently, and characters were affected to different degrees. Multiple measurements over time showed that almost all changes occurred within 3 weeks of preservation. Regression equations allowed for accurate correction of preservation effects on morphometric measurements, but the effects on pigmentation levels were less predictable. Effects of preservation on larval lampreys need to be considered when comparing fresh and preserved specimens because they influence critical identification features.
The effects of carotenoid and food intake on caudal fin regeneration in male guppies
Authors: Kolluru G. R. , Ruiz N. C. , Del Cid N. , Dunlop E. , Grether G. F.
Published: April 2006

The trade‐offs involved in allocating carotenoid pigments and food to healing and regrowing damaged caudal fin tissue v. other functions were examined in guppies Poecilia reticulata, a species in which females prefer males that display larger amounts of carotenoids in their skin. The guppies were derived from four natural populations in Trinidad that differed in resource availability but not predation intensity. Carotenoids, food and site of origin did not affect either absolute or relative fin regrowth, which suggested that fin regeneration in guppies was not constrained by carotenoid availability. It is possible that carotenoid intake influences fin regeneration in the presence of natural stressors such as predators. There was a significant negative interaction between food level in the laboratory and resource availability in the field: males from low‐resource‐availability sites regrew more fin tissue when raised on the high food level, and males from high‐resource‐availability sites regrew more fin tissue when raised on the low food level. The direction of this interaction runs counter to theoretical expectations.
Feeding ecology and habitat preferences of the catfish genus Trichomycterus in low‐order streams of the Colombian Andes
Authors: Chará J. D. , Baird D. J. , Telfer T. C. , Rubio E. A.
Published: April 2006

Six lower order streams in the south‐west of Colombia were sampled on a monthly basis in order to determine the status of Trichomycterus species in relation to their food supply (macroinvertebrates), and physico‐chemical habitat. Fishes were sampled by electrofishing and samples taken for dietary analysis. Macroinvertebrates were collected using a Surber sampler. Trichomycterus spp. populations were present in all streams in habitats ranging from soft to hard substrata and from relatively stagnant waters to fast flowing streams. The average density of the fishes ranged from 0·06 to 1·14 individuals m−2 with peaks in population corresponding to recruitment of individuals of <1 g. Trichomycterus spp. were found to be benthic carnivores with a diet mostly of aquatic insects. The index of relative importance for the dietary items was 35·0, 10·5, 1·9 and 7·8% for Chironomidae, Trichoptera, Ephemeroptera and Oligochaeta respectively. Combined with physical habitat data, ordinations of fishes and macroinvertebrate data suggested that differences in abundance among sites were driven by stream size and flow regime, indicating dominance of the physical habitat, although a high correlation between Trichomycterus spp. and Chironomidae abundances (r = 0·81, P = 0·049) was also recorded.
The effect of temperature and fish size on growth and feed efficiency ratio of juvenile spotted wolffish Anarhichas minor
Authors: Imsland A. K. , Foss A. , Sparboe L. O. , Sigurdsson S.
Published: April 2006

The growth properties of juvenile spotted wolffish Anarhichas minor reared at 4, 6, 8 and 12° C, and a group reared under ‘temperature steps’, (T‐step)i.e. with temperature reduced successively from 12 to 9 and 6° C were investigated. Growth rate and feed efficiency ration was significantly influenced by temperature and fish size. Overall growth rate was highest at 6° C (0·68% day−1) and lowest at 12° C (0·48% day−1), while the 4 and 8° C, and the T‐step groups had similar overall growth rates, i.e. 0·59, 0·62 and 0·51% day−1 respectively. Optimal temperature for growth (Topt G) and feed efficiency ratio (Topt FCE) decreased as fish size increased, indicating an ontogenetic reduction in Topt G and Topt FCE. The results suggest a Topt G of juvenile spotted wolffish in the size range 135–380 g, dropping from 7·9° C for 130–135 g to 6·6° C for 360–380 g juveniles. The Topt FCE dropped from 7·4° C for 120–150 g to 6·5° C for 300–380 g juveniles. A wider parabolic regression curve between growth, feed efficiency ratio and temperature as fish size increased, may indicate increased temperature tolerance with size. Individual growth rates varied greatly at all time periods within the experimental temperatures, but at the same time significant size rank correlations were maintained and this may indicate stable size hierarchies in juvenile spotted wolffish.
Growth, maturity and fecundity of wolffish Anarhichas lupus L. in Icelandic waters
Authors: Gunnarsson Á. , Hjörleifsson E. , Thórarinsson K. , Marteinsdóttir G.
Published: April 2006

Fecundity, maturity and the relationship between growth and maturity of common wolffish Anarhichas lupus were studied in Icelandic waters. A total of 788 female common wolffish were sampled in two areas: one in the relatively warm sea west of Iceland and the other in the colder sea east of Iceland. No difference was detected in fecundity of common wolffish between areas. The time from the onset of the cortical alveolus stage until spawning, was on average, 10 years in the east and 8 years in the west area. Common wolffish in the east area reached cortical alveolus stage, on average, at a greater age but similar size compared to common wolffish in the west area. Similarly, common wolffish started spawning, on average, at greater age and larger size in the east than in the west area. Common wolffish grew faster in the west than in the east area. Spawning common wolffish grew faster than common wolffish at the cortical alveolus stage in both areas. The relationship between growth and maturity for common wolffish in Icelandic waters appeared to be related to temperature, characterized by fast growth and early maturation in the west and slower growth and delayed maturation in the east.
The effect of size on the timing of visually mediated escape behaviour in staghorn sculpinLeptocottus armatus
Authors: Paglianti A. , Domenici P.
Published: April 2006

The effect of prey size on the timing of the startle response in the sculpinLeptocottus armatuswas investigated. Escape responses were triggered visually by a looming image obtained using a computer‐generated animation of an approaching black disk. The results showed that apparent looming threshold (TAL,i.e.the threshold at which the rate of change of the visual angle subtended by predator frontal profile onto the prey's eye triggers an escape response by the prey) decreased with increasing prey size. Distance travelled within a fixed time was unaffected by size. Theoretical considerations suggest that larger prey would need to travel a longer distance (and so they would need more time) in order to move their whole body outside the predator's approaching gape. Therefore, the scaling ofTALmay be explained by taking into account both ultimate and proximate considerations that need not be mutually exclusive. At an ultimate level, lowerTALin larger fish may be explained in terms of offsetting the disadvantage of offering a larger volume to be intercepted by the predator. At a proximate level,TALmay be related to the fish's visual acuity, which is higher in larger fish.
The effects of introduced salmonids on two native stream‐dwelling salmonids through interspecific competition
Authors: Hasegawa K. , Maekawa K.
Published: April 2006

Using an artificial stream, habitat use by two sympatric native salmonids in the presence and absence of introduced salmonid species was investigated experimentally. When only native white‐spotted charr Salvelinus leucomaenis and masu salmon Oncorhynchus masou were sympatric, they occupied different microhabitats. In the presence of introduced brown trout Salmo trutta or rainbow trout Oncorhynchus mykiss, however, white‐spotted charr and masu salmon were observed to use a similar habitat and interspecific competition between white‐spotted charr and masu salmon was initiated. The study suggested that the coexistence of native salmonids was negatively affected through interspecific competition between native and introduced salmonids.
Chondroid bone and secondary cartilage contribute to apical dentary growth in juvenile Atlantic salmon
Authors: Gillis J. A. , Witten P. E. , Hall B. K.
Published: April 2006

The microstructure and tissue composition of the dentary bone in Atlantic salmonsalmo salarparr were examined using a variety of histological and whole‐mount techniques. Proximally, the dentary is composed of typical cellular lamellar bone with Sharpey's fibres extending dorsally, proximally and ventrally. Meckel's cartilage is located medially through the entire length of the dentary, and degrades distally resulting in a short transitional zone between hyaline cartilage and connective tissue. At the distal tip of the dentary, isogenic clusters of chondrocytes of periosteal origin were observed secreting small amounts of pericellular cartilage matrix within the bone matrix. These characteristics are highly indicative of secondary chondrogenesis, and suggest that the apical part of the dentary bone in Atlantic salmon does not growvia‘pure’ intramembranous ossification, but ratherviaa modified mode of periosteal ossification involving secondary cartilage and chondroid bone. Furthermore, the unusual mode of gender‐related dentary growth (kype formation) in adult male Atlantic salmon could be the continuation of a general mode of salmonid apical dentary growth.
Ontogenetic variability in external morphology and microhabitat use of spirlin Alburnoides bipunctatus from the River Rudava (Danube catchment)
Authors: Kováč V. , Katina S. , Copp G. H. , Siryová S.
Published: April 2006

The external morphometry of spirlin Alburnoides bipunctatus, a threatened species in parts of its native range, was re‐examined in specimens from the River Rudava, Slovakia, using geometrical shape analysis, and the relationships between morphometry and habitat use were evaluated. Spirlin <40 mm standard length (LS)(early and ‘middle’ juveniles) were found to differ significantly from those >51 mm (adults), whereas individuals between 41 and 50 mm LS(late juveniles) represented an intermediate interval during which major changes in shape appeared to occur. Adults had proportionally smaller eyes, deeper body, and longer preanal part of the body than the early and ‘middle’ juveniles. These differences tended to coincide with the differences observed in microhabitat use of spirlin, namely a generally increasing preference for high velocity areas with increasing age of the fish. Thus, changes in external morphometry occurring during the ontogeny of spirlin might reflect an increasing affinity for more complex, lotic microhabitats as well as developments associated with sexual maturation.
Correlations between type‐indicator fish species and lake productivity in German lowland lakes
Authors: Garcia X.‐F. , Diekmann M. , Brämick U. , Lemcke R. , Mehner T.
Published: April 2006

Morphotypes for 67 lakes in the German lowlands were derived, based on maximum depth and mixis type. A threshold of 11 m maximum depth was identified to be the best level to discriminate shallow from deep lake morphotypes. The fish communities in these two morphotypes were significantly different. Indicator species analyses based on fish biomasses found vendace Coregonus albula in deep lakes and ruffe Gymnocephalus cernuus, bream Abramis brama, white bream Abramis bjoerkna, roach Rutilus rutilus, pikeperch Sander lucioperca and small perch Perca fluviatilis in shallow lakes to be the most representative species of their communities. Lake productivity was closely related to biomass and in part abundance of the type‐indicator species, with vendace declining with increasing chlorophyll a concentration in the deep lakes, whereas biomass of pikeperch, bream, white bream and ruffe increased and biomass of small perch decreased with increasing chlorophyll a. These results indicate that assessment of ecological integrity of lakes by their fish fauna is generally possible, if lakes are initially separated according to a depth‐related morphotype before the assessment, and if eutrophication is considered to be the main anthropogenic degradation.
Nest guarding in a damselfish: evidence of a role for parasites
Authors: Sasal P.
Published: April 2006

A potential effect of parasitism on male egg loss while guarding was tested using damselfishStegastes planifrons. Despite an apparent low energetic cost of the parasite on the male condition, there was a significant positive relationship between egg loss and parasite load. These data provide the first evidence that parasites could play a role in male guarding behaviour. The effect of the parasite could have resulted in low male condition compensated by an increase in filial cannibalism or in a lesser ability to protect the nest from predators.
Heparin‐binding epidermal growth factor‐like growth factor as a novel targeting molecule for cancer therapy
Authors: Miyamoto Shingo , Yagi Hiroshi , Yotsumoto Fusanori , Kawarabayashi Tatsuhiko , Mekada Eisuke
Published: April 2006

HB‐EGF, a member of the EGF family of growth factors, exerts its biological activity through activation of the EGFR and other ErbB receptors. HB‐EGF participates in diverse biological processes, including heart development and maintenance, skin wound healing, eyelid formation, blastocyst implantation, progression of atherosclerosis and tumor formation, through the activation of signaling molecules downstream of ErbB receptors and interactions with molecules associated with HB‐EGF. Recent studies have indicated that HB‐EGF gene expression is significantly elevated in many human cancers and its expression level in a number of cancer‐derived cell lines is much higher than those of other EGFR ligands. Several lines of evidence have indicated that HB‐EGF plays a key role in the acquisition of malignant phenotypes, such as tumorigenicity, invasion, metastasis and resistance to chemotherapy. Studies in vitro and in vivo have indicated that HB‐EGF expression is essential for tumor formation of cancer‐derived cell lines. CRM197, a specific inhibitor of HB‐EGF, and an antibody against HB‐EGF are both able to inhibit tumor growth in nude mice. These results indicate that HB‐EGF is a promising target for cancer therapy, and that the development of targeting tools against HB‐EGF could represent a novel type of therapeutic strategy, as an alternative to targeting ErbB receptors. (Cancer Sci 2006; 97: 341–347)
Mouse models of gastrointestinal tumors
Authors: Taketo Makoto Mark
Published: April 2006

The laboratory mouse (Mus musculus) has become one of the best model animal species in biomedical research today because of its abundant genetic/genomic information, and easy mutagenesis using transgenic and gene knockout technology. Genetically engineered mice have become essential tools in both mechanistic studies and drug development. In this article I will review recent topics in gastrointestinal cancer model mice, with emphasis on the results obtained in our laboratory. They include: (i) mouse models for familial adenomatous polyposis (Apc mutant mice; modifier genes of Apc intestinal polyposis; stabilizing β‐catenin mutant mice); (ii) mouse models for colon cancer (mouse models for hereditary non‐polyposis colon cancer; additional mutations in Apc mutant mice; models with mutations in other genes; models for colon cancer associated with inflammatory bowel diseases); and (iii) mouse models for gastric cancer. (Cancer Sci 2006; 97: 355 –361)