bluuebunny/crossref_metadata_2025 huggingface dataset:
Depression in Irish migrants living in London: case-control study
Authors: Ryan Louise , Leavey Gerard , Golden Anne , Blizard Robert , King Michael
Published: May 2006

Background

There is evidence that Irish migrants in Britain have higher rates of depression and suicide than other minority ethnic groups.

Aims

To examine the association between poorly planned migration and depression in Irish-born people living in London.

Method

A sample of 360 Irish-born people was recruited from 11 general practices into a case-control study Participants were interviewed using standardised measures, including the Beck Depression Inventory (BDI). We calculated the odds ratio for any association between depression and eight questions on preparation for migration.

Results

Poorly planned migration was associated with subsequent depression in Irish-born people living in London (OR=1.20, 95% CI 1.06-l.35). The odds of depression were increased by a factor of 20% for each additional negative answer to eight questions on preparation for migration. Positive post-migration influences such as adequate social support protected some against depression.

Conclusions

Depression in Irish-born people living in London is associated with poorly planned migration. However, this effect can be modified by experiences following migration.
Socio-economic deprivation and duration of hospital stay in severe mental disorder
Authors: Abas Melanie Amna , Vanderpyl Jane , Robinson Elizabeth , Prou Trix Le , Crampton Peter
Published: May 2006

Adults from South Auckland, New Zealand who required acute admission to hospital were followed from admission to discharge. After adjusting for demographic factors, diagnosis, chronicity, severity, consultant psychiatrist and involuntary admission, the length of stay for those from more deprived areas was significantly longer by 7 days than for those from less deprived areas. Information on socio-economic deprivation should be used in discharge planning and in optimising access to community care. Research is needed on group-level factors that may affect recovery from mental disorders.
Use of a routine mental health measure in an adolescent secure unit
Authors: Yates Peter , Kramer Tami , Garralda M. Elena
Published: May 2006

We examined the use of a staff-completed measure, the Health of the Nation Outcome Scales for Children and Adolescents (HoNOSCA), to record mental health problems in adolescents in local authority secure accommodation. It proved possible to train staff and implement completion of the HoNOSCA on 64 consecutive admissions. Interrater reliability was high. The HoNOSCA identified high levels of psychological problems on admission (mean 18.5, s.d.=5.5). Follow-up HoNOSCA ratings proved sensitive to change; however, correlation between HoNOSCA and adolescent-completed questionnaires was poor. We concluded that HoNOSCA can be helpful in documenting mental health problems among young people admitted to secure local authority units.
Rituximab in the Treatment of Acquired Hemophilia
Authors: Stachnik Joan M
Published: May 2006

Objective:

To review published literature evaluating the use of rituximab for treatment of acquired hemophilia.

Data Sources:

An English-language literature search was conducted using MEDLINE (1966–January 2006). References of identified articles were subsequently reviewed for additional data. Search terms included rituximab, acquired hemophilia, and inhibitors.

Data Synthesis:

Available data suggest that B-cell depletion by rituximab in patients with acquired hemophilia may contribute to the eradication of inhibitors to coagulation factors. B-cells have been shown to be essential in the development of autoimmunity or an acquired immune response. Beneficial effects of rituximab, after failure of established therapies, have been reported in case reports and one small, open-label trial.

Conclusions:

Although data are limited, administration of rituximab appears to be an effective option for treatment of patients with acquired hemophilia after established therapies have failed. Patients given rituximab experienced cessation of recurrent bleeding, normalization of factor VIII activity, and eradication of inhibitors. A complete response to rituximab (undetectable inhibitors, normalization of factor levels) generally occurred several weeks to months after initiation of therapy.
Culture, personal experience and agency
Authors: McCarthy John , Sullivan Paul , Wright Peter
Published: May 2006

In this article, we explore what we perceive to be a gap between agency as articulated in practice theories and agency as personally experienced. The gap is not created by a turn to practice in theorizing, but by the tendency to produce theoretical representations that silence the particularity of experience and the diversity of voices in experience. In exploring the gap, we identify aspects of practice theories that explicitly commit to theoretical representation over personal experience and describe Bakhtin's commitment to action and personal experience as an alternative. In order to exemplify Bakhtin's approach in practice, we then present an analysis of one artist‐teacher's experience of her own agency in making art and in teaching. Finally, we comment on what a commitment to representational theorizing does to accounts of an artist's activities and personal experience.
Heat-induced Antigen Retrieval: What Are We Retrieving?
Authors: Boenisch Thomas
Published: May 2006

Of all molecular aspects lost and recovered during formalin fixation and antigen retrieval, respectively, electrostatic charges have probably received the least attention. This review will focus on our work during the past 7 years. It strongly supports the tenet that electrostatic charges, i.e., net negative on antigens and net positive on antibodies, play an important part in immune reactions and therefore should be given greater attention when focusing on quality control in immunohistochemistry.
Roles of the Fast-Releasing and the Slowly Releasing Vesicles in Synaptic Transmission at the Calyx of Held
Authors: Sakaba Takeshi
Published: May 2006

In the calyx of Held, fast and slow components of neurotransmitter release can be distinguished during a step depolarization. The two components show different sensitivity to molecular/pharmacological manipulations. Here, their roles during a high-frequency train of action potential (AP)-like stimuli were examined by using both deconvolution of EPSCs and presynaptic capacitance measurements. During a 100 Hz train of AP-like stimuli, synchronous release showed a pronounced depression within the 20 stimuli. Asynchronous release persisted during the train, was variable in its amount, and was more prominent during a 300 Hz train. We have shown previously that slowly releasing vesicles were recruited faster than fast-releasing vesicles after depletion. By further slowing recovery of the fast-releasing vesicles by inhibiting calmodulin-dependent processes (Sakaba and Neher, 2001b), the slowly releasing vesicles were isolated during recovery from vesicle depletion. When a high-frequency train was applied, the isolated slowly releasing vesicles were released predominantly asynchronously. In contrast, synchronous release was mediated mainly by the fast-releasing vesicles. The results suggest that fast-releasing vesicles contribute mainly to synchronous release and that depletion of fast-releasing vesicles shape the synaptic depression of the synchronous phase of EPSCs, whereas slowly releasing vesicles are released mainly asynchronously during high-frequency stimulation. The latter is less subject to depression presumably because of a rapid vesicular recruitment process, which is a characteristic of this component.
Upper Temperature Tolerance of Loach Minnow under Acute, Chronic, and Fluctuating Thermal Regimes
Authors: Widmer Ann M. , Carveth Corissa J. , Bonar Scott A. , Simms Jeffrey R.
Published: May 2006

We used four methods to estimate the upper lethal temperature of loach minnow Rhinichthys cobitis: The lethal thermal method (LTM), chronic lethal method (CLM), acclimated chronic exposure (ACE) method with static temperatures, and ACE method with diel temperature fluctuations. The upper lethal temperature of this species ranged between 32°C and 38°C, depending on the method and exposure time; however, temperatures as low as 28°C resulted in slowed growth compared with the control groups. In LTM trials, we increased temperatures 0.3°C/min and death occurred at 36.8 ± 0.2°C (mean ± SE) for fish (37–49 mm total length) acclimated to 30°C and at 36.4 ± 0.07°C for fish acclimated to 25°C. In CLM trials, temperatures were increased more slowly (1°C/d), allowing fish to acclimate. Mean temperature at death was 33.4 ± 0.1°C for fish 25–35 mm and 32.9 ± 0.4°C for fish 45–50 mm. In the ACE experiment with static temperatures, we exposed fish for 30 d to four constant temperatures. No fish (20–40 mm) survived beyond 30 d at 32°C and the 30‐d temperature lethal to 50% of the test animals was 30.6°C. Growth at static 28°C and 30°C was slower than growth at 25°C, suggesting that fish were stressed at sublethal temperatures. In ACE trials with diel temperature fluctuations of 4, 6, and 10°C and a 32°C peak temperature, over 80% of fish (20–40 mm) survived 30 d. Although brief exposures to 32°C were not lethal, the growth of fish in the three fluctuating‐temperature treatments was significantly less than the growth at the ambient temperature (25–29°C). To minimize thermal stress and buffer against temperature spikes, we recommend that loach minnow habitat be managed to avoid water temperatures above 28°C.
Defining Flow Windows for Upstream Passage of Adult Anadromous Salmonids at Cascades and Falls
Authors: Reiser Dudley W. , Huang Chi‐Ming , Beck Stuart , Gagner Michael , Jeanes Eric
Published: May 2006

Variations in streamflow at falls and cascades can create transitory barriers to upstream passage of adult anadromous salmonids. In this study, we evaluated the ability of six anadromous salmonids (coho salmon Oncorhynchus kisutch, pink salmon O. gorbuscha, chum salmon O. keta, sockeye salmon O. nerka, Chinook salmon O. tshawytscha, and steelhead O. mykiss) to pass five sets of falls or cascades within Ward Creek, Alaska, a stream regulated by Connell Dam. The study focused on determining suitable instream flow releases to afford passage. Each set of falls was surveyed under three flow conditions (about 0.91, 1.34, and 3.0 m3/s), and access portals were identified. Using computed stage—discharge relationships and published swimming and jumping criteria, we evaluated the falls barrier potential over a range (0.23–11.33 m3/s) of flows. Analysis indicated pink salmon and chum salmon would be relegated to the area below the lower two falls. Flows affording passage over all five falls for the other species (excluding Chinook salmon) were defined as “flow windows” and ranged from 0.66 to 3.01 m3/s. Flow windows varied by species; the narrowest range of acceptable passage flows was found for sockeye salmon, the widest was found for steelhead, and the range for coho salmon was intermediate. Escapement surveys generally confirmed our analysis; pink salmon and chum salmon were only found below the lowermost falls. The flow windows for passage were compatible with a set of instream flow recommendations derived via a PHABSIM‐based study but were incompatible with the highest flow recommendation based on the method of Tennant (1976). Care must be taken when evaluating instream flow needs to ensure that all flow‐sensitive factors are considered.
The Use of Different Measurements and Definitions of Periodontal Disease in the Study of the Association Between Periodontal Disease and Risk of Myocardial Infarction
Authors: Andriankaja Oelisoa M. , Genco Robert J. , Dorn Joan , Dmochowski Jacek , Hovey Kathy , Falkner Karen L. , Scannapieco Frank , Trevisan Maurizio
Published: May 2006

Background: The role of periodontal disease as an independent risk factor for cardiovascular disease (CVD) has been under debate because of the inconsistency of findings across studies. One of the major issues is the method used to assess or define periodontal disease. The present study assesses if the observed association between periodontal disease and incident myocardial infarction (MI) depends on the measurements and/or criteria used to define periodontal disease.

Methods: A population‐based case‐control study to evaluate the association between PD and risk of MI was conducted between 1997 and 2001 in Western New York with 537 cases and 800 controls, aged 35 to 69 years. Cases were survivors of incident MI from local hospitals in Erie and Niagara counties. Controls were randomly selected from residents of the same counties. Periodontal disease was assessed using interproximal clinical attachment loss (CAL), probing depth (PD), alveolar crest height (ACH), and number of missing teeth. From these measurements, four different case definitions of periodontal disease were created.

Results: Using the continuous forms of periodontal measurements, the odds ratios (ORs) (95% confidence interval) of the association with incident MI were 1.46 (1.26 to 1.69), 2.19 (1.66 to 2.89), 1.30 (1.14 to 1.49), and 1.04 (1.02 to 1.07) for mean CAL, PD, ACH, and number of missing teeth, respectively. Regardless of the case definition of periodontal disease, the estimates of the association with incident MI were statistically significant.

Conclusions: The observed association between periodontal disease and incident MI was consistent across different measurements and/or case definitions of periodontal disease used. The magnitude of the association varies depending on the measurements or the criteria used to define periodontal disease.
Gastric Bypass Surgery in the United States, 1998–2002
Authors: Smoot Tonya M. , Xu Ping , Hilsenrath Peter , Kuppersmith Nancy C. , Singh Karan P.
Published: May 2006

We assessed the prevalence of gastric bypass surgeries in the United States on the basis of data from the 1998 to 2002 National Hospital Discharge Survey. Between 1998 and 2002, rates (per 100 000 adults) increased significantly (P<.001): from 7.0 to 38.6. This observed increase in the rate of gastric bypass surgery for the treatment of obesity may be attributed in part to improvements in surgical technique, improved patient outcomes, and increased popularity of this procedure.
Family Socioeconomic Position at Birth and Future Cardiovascular Disease Risk: Findings From the Aberdeen Children of the 1950s Cohort Study
Authors: Lawlor Debbie A. , Ronalds Georgina , Macintyre Sally , Clark Heather , Leon David A.
Published: May 2006

Objectives. We assessed the association of father’s social class, recorded at the time of birth, with coronary heart disease and stroke in a British cohort of 11106 individuals born in the 1950s.

Methods. Survival analysis was used to relate social class at birth to the occurrence of either fatal or nonfatal coronary heart disease or stroke.

Results. Rates of coronary heart disease and stroke increased across the social class distribution from highest to lowest, and patterns of association were similar for the 2 outcomes. The gender-adjusted hazard ratio of experiencing either coronary heart disease or stroke comparing the manual and nonmanual social class categories was 1.52 (95% confidence interval [CI]=1.14, 2.02). This ratio fell to 1.41 (95% CI = 1.05, 1.88) after adjustment for indicators of intrauterine and childhood growth. Further adjustment for educational attainment reduced the ratio to 1.28 (95% CI=0.94, 1.75).

Conclusions. We found that social class at birth was associated with risk of fatal and nonfatal cardiovascular disease among individuals born in the 1950s, a period of relative prosperity and after the introduction of the welfare state in Britain. This relation appeared to be mediated in part through educational attainment.
Advances in antimicrobial peptide immunobiology
Authors: Yount Nannette Y. , Bayer Arnold S. , Xiong Yan Q. , Yeaman Michael R.
Published: May 2006

Antimicrobial peptides are ancient components of the innate immune system and have been isolated from organisms spanning the phylogenetic spectrum. Over an evolutionary time span, these peptides have retained potency, in the face of highly mutable target microorganisms. This fact suggests important coevolutionary influences in the host–pathogen relationship. Despite their diverse origins, the majority of antimicrobial peptides have common biophysical parameters that are likely essential for activity, including small size, cationicity, and amphipathicity. Although more than 900 different antimicrobial peptides have been characterized, most can be grouped as belonging to one of three structural classes: (1) linear, often of α‐helical propensity; (2) cysteine stabilized, most commonly conforming to β‐sheet structure; and (3) those with one or more predominant amino acid residues, but variable in structure. Interestingly, these biophysical and structural features are retained in ribosomally as well as nonribosomally synthesized peptides. Therefore, it appears that a relatively limited set of physicochemical features is required for antimicrobial peptide efficacy against a broad spectrum of microbial pathogens.

During the past several years, a number of themes have emerged within the field of antimicrobial peptide immunobiology. One developing area expands upon known microbicidal mechanisms of antimicrobial peptides to include targets beyond the plasma membrane. Examples include antimicrobial peptide activity involving structures such as extracellular polysaccharide and cell wall components, as well as the identification of an increasing number of intracellular targets. Additional areas of interest include an expanding recognition of antimicrobial peptide multifunctionality, and the identification of large antimicrobial proteins, and antimicrobial peptide or protein fragments derived thereof. The following discussion highlights such recent developments in antimicrobial peptide immunobiology, with an emphasis on the biophysical aspects of host‐defense polypeptide action and mechanisms of microbial resistance. © 2006 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 84: 435–458, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Adsorption of albumin on prosthetic materials: Implication for tribological behavior
Authors: Serro A.P. , Gispert M.P. , Martins M.C.L. , Brogueira P. , Colaço R. , Saramago B.
Published: May 2006

The orthopedic prosthesis used to substitute damaged natural joints are lubricated by a pseudosynovial fluid that contains biological macromolecules with potential boundary lubrication properties. Proteins are some of those macromolecules whose role in the lubrication process is not yet completely understood. In a previous work, we investigated the influence of the presence of albumin, the major synovial protein, upon the tribological behavior of three of the most used pairs of artificial joint materials: ultra high molecular weight polyethylene (UHMWPE) against counterfaces of alumina, CoCrMo alloy, and 316L stainless steel. Albumin was found to cause a significant decrease in the friction coefficient when the counterfaces were metallic because transfer of UHMWPE was avoided, but this effect was much weaker in the case of alumina. The objective of the present work was to look for an explanation for these differences in tribological behavior in terms of albumin adsorption. With this goal, studies on adsorption of bovine serum albumin (BSA) on the counterface materials, from a biological model fluid (Hanks' balanced salt solution), were carried out using radiolabeled albumin (125I‐BSA), X‐ray photoelectron spectroscopy, and atomic force microscopy. The conclusion from all techniques is that the driving force for albumin adsorption is higher on the metals than on alumina. These results confirm that the greater the amount of protein adsorbed on the counterface, the more efficient is the protection against the transfer of polymeric film to the counterface. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Influence of different restorative materials on lysozyme and amylase activity of the salivary pellicle in situ
Authors: Hannig Christian , Wasser Mathias , Becker Klaus , Hannig Matthias , Huber Karin , Attin Thomas
Published: May 2006

Lysozyme and amylase are the most abundant enzymatic components in the salivary pellicle. The purpose of the present study was to determine the influence of different substrata on amylase and lysozyme activity in salivary pellicles formed in situ. Slabs (5 mm diameter) of bovine dentine and enamel, of titanium, gold alloy, resin composite, PMMA, amalgam, and feldspar ceramic were fixed on the buccal sites of individual splints worn by six subjects for 30 min to allow pellicle formation. Thereafter, slabs were removed from the trays and rinsed with running water. Lysozyme activity was determined via lysis of Micrococcus lysodeicticus. Amylase activity was measured with a photometric method using 2‐chloro‐4‐nitrophenyl‐4‐O‐β‐D‐galactopyranosylmaltotriosid (GalG2CNP) as substrate. Both pellicle enzymes were evaluated in the immobilized as well as in the desorbed state. Salivary enzyme activities were also measured. All investigated pellicles exhibited lysozyme and amylase activity. Great intraindividual and interindividual differences were observed. Over all samples, immobilized amylase activity amounted to 0.65 ± 0.64 mU/cm2. Immobilized lysozyme activity was 5.04 ± 1.55 U/cm2. There were no major effects of the substratum on pellicle‐bound amylase and lysozyme activity. Immobilized and desorbed enzyme activities revealed a strong correlation (lysozyme: r = 0.700; amylase: r = 0.990). Salivary enzyme activities had only little impact on pellicle‐bound enzyme activities. Amylase and lysozyme are incorporated in the acquired in situ pellicle on different solid surfaces in an active conformation. Dental material and enzyme activity in the saliva have only little impact on enzymatic activity in the pellicle in situ. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Non‐invasive detection of antibiotics and physiological substances in the aqueous humor by raman spectroscopy
Authors: Sideroudi Theoharia I. , Pharmakakis Nikolaos M. , Papatheodorou George N. , Voyiatzis George A.
Published: May 2006

Background and Objectives

Laser Raman spectroscopy is an inelastic light scattering technique able to characterize molecules in aqueous environments. The purpose of this work is to develop a non‐contact and non‐invasive spectroscopic method to identify and eventually quantify the presence of medicines (e.g., antibiotics) and physiological substances (e.g., glucose) in the aqueous humor of the eye.

Study Design/Materials and Methods

A new laser light delivery probe has been developed and adapted to a Raman spectroscopic system with the ability of favorable collection of the Raman light at 90° scattering geometry while scanning the anterior chamber of the eye. Different amounts of ceftazidime, amphotericin B, and glucose had been injected in the aqueous humor of porcine eyes, maximum 24 hours after death and extraction, in‐vitro. Raman measurements were excited with a visible (514.5 nm) laser beam at a power of 25 mW and an exposure/acquisition time of 1 second.

Results

The specific collection optics and Raman analysis components used in the present work have resolved the Raman signatures of probed molecules and low concentrations of ceftazidime (0.9 mg/mL), amphotericin B (9 µg/mL), and glucose (2 mg/ml) separately injected in the anterior chamber of porcine eyes were detected in vitro.

Conclusion

This special illumination design gives the opportunity of avoiding the direct exposure to the laser light of basic cordial tissues of the eye, like lens and retina, although an optimum collection of scattered light is accomplished. Concentrations close to the minimum inhibitory concentration (MIC) have been detected for ceftazidime and amphotericin b; the detection of glucose has been realized at concentrations close to the early pathological levels of patients with diabetes. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.
EGFR amplification and lack of activating mutations in metaplastic breast carcinomas
Authors: Reis‐Filho JS , Pinheiro C , Lambros MBK , Milanezi F , Carvalho S , Savage K , Simpson PT , Jones C , Swift S , Mackay A , Reis RM , Hornick JL , Pereira EM , Baltazar F , Fletcher CDM , Ashworth A , Lakhani SR , Schmitt FC
Published: May 2006

Metaplastic breast carcinomas are reported to harbour epidermal growth factor receptor (EGFR) overexpression in up to 80% of the cases, but EGFR gene amplification is the underlying genetic mechanism in around one‐third of these. In this study, EGFR gene amplification as defined by chromogenic in situ hybridization and protein overexpression was examined in a cohort of 47 metaplastic breast carcinomas. Furthermore, the presence of activating EGFR mutations in exons 18, 19, 20, and 21 was investigated. Thirty‐two cases showed EGFR overexpression and of these, 11 (34%) harboured EGFR gene amplification. In addition, EGFR amplification showed a statistically significant association with EGFR overexpression (p < 0.0094) and was restricted to carcinomas with homologous metaplasia. Ten cases, five with and five without EGFR amplification, were subjected to microarray‐based CGH, which demonstrated that EGFR copy number gain may occur by amplification of a discrete genomic region or by gains of the short arm of chromosome 7 with a breakpoint near the EGFR gene locus, the minimal region of amplification mapping to EGFR, LANCL2, and SEC61G. No activating EGFR mutations were identified, suggesting that this is unlikely to be a common alternative underlying genetic mechanism for EGFR expression in metaplastic breast carcinomas. Given that metaplastic breast carcinomas are resistant to conventional chemotherapy or hormone therapy regimens and that tumours with EGFR amplification are reported to be sensitive to EGFR tyrosine kinase inhibitors, these findings indicate that further studies are warranted to explore EGFR tyrosine kinase inhibitors as potential therapeutic agents for metaplastic breast carcinomas harbouring amplification of 7p11.2. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Proteomic analysis of tomato fruits from two ecotypes during ripening
Authors: Rocco Mariapina , D'Ambrosio Chiara , Arena Simona , Faurobert Mirelle , Scaloni Andrea , Marra Mauro
Published: May 2006

Ripening of climacteric fruits is a complex physiological phenomenon, which makes berries attractive/palatable and also determines their nutritional characteristics. We report here a comparative proteomic investigation on tomato fruits from a regional and commercial elite ecotype during maturation. Several hundreds of protein components were resolved on 2‐DE gels (pH range 4–7) stained with colloidal Coomassie; almost 57% presented overlapping gel coordinates between the two compared varieties. Specific proteins were recognized in each ecotype as differentially expressed during ripening. Constant and variable components were excised, in‐gel digested and analysed by MALDI‐TOF‐MS and µLC‐ESI‐IT‐MS/MS approaches. Peptide MS and MS/MS data were searched against publicly available protein and EST databases, and 83 protein spots were unambiguously identified by MS. Gel matching procedures allowed further identification of proteins between ecotypes. In general, common variably expressed proteins in both ecotypes during maturation were associated to important physiological processes such as redox status control, defence, stress, carbon metabolism, energy production and cellular signalling. Protein components differentially expressed in each variety were also identified. The role of some of the identified proteins in the berries is discussed in relation to tomato fruit ripening. Accordingly, this investigation provides the first characterization of the tomato fruit proteome and description of its variation during maturation.
Reduction of noise in strapped magnetron by electric priming using anode shape modification
Authors: Kim J. I. , Won J. H. , Park G. S. , Ha H. J. , Shon J. C.
Published: May 2006

Noise reduction in a 2.45GHz strapped magnetron oscillator is experimentally demonstrated by electric priming using anode shape modification. The sideband noise is reduced by approximately 15dB at the nominal operating current and by 28dB at the start-oscillation current; this is due to electron prebunching into the π mode, resulting from the modulation of the drift velocity of the electrons by an azimuthally periodic electric field. In this experiment, a 4.3kV–330mA half-wave rectified input power is employed.
5
GHz
surface acoustic wave devices based on aluminum nitride/diamond layered structure realized using electron beam lithography
Authors: Kirsch P. , Assouar M. B. , Elmazria O. , Mortet V. , Alnot P.
Published: May 2006

Very high frequency surface acoustic wave (SAW) devices based on AlN/diamond layered structures were fabricated by direct writing using e-beam lithography on the nucleation side of chemical vapor deposition diamond. The interdigital transducers made in aluminum with resolutions down to 500nm were patterned on AlN/diamond layered structure with an adapted technological process. Experimental results show that the Rayleigh wave and the higher modes are generated. The fundamental frequency around 5GHz was obtained for this layered structure SAW device and agrees well with calculated results from dispersion curves of propagation velocity and electromechanical coupling coefficient.
Directed growth of single-crystal indium wires
Authors: Talukdar Ishan , Ozturk Birol , Flanders Bret N. , Mishima Tetsuya D.
Published: May 2006

Tailored electric fields were used to direct the dendritic growth of crystalline indium wires between lithographic electrodes immersed in solutions of indium acetate. Determination of the conditions that suppress sidebranching on these structures has enabled the fabrication of arbitrarily long needle-shaped wires with diameters as small as 370nm. Electron diffraction studies indicate that these wires are crystalline indium, that the unbranched wire segments are single-crystal domains, and that the predominant growth direction is near ⟨110⟩. This work constitutes a critical step towards the use of simply prepared aqueous mixtures as a convenient means of controlling the composition of submicron, crystalline wires.
Imperfect oriented attachment: Direct activation of high-temperature ferromagnetism in diluted magnetic semiconductor nanocrystals
Authors: Wang Xuefeng , Xu J. B. , Ke Ning , Yu Jiaguo , Wang Juan , Li Quan , Ong H. C. , Zhang R.
Published: May 2006

We report on a simple nonequilibrium solvothermal synthesis of Co-doped ZnO diluted magnetic semiconductor (DMS) nanocrystals. The crystal growth mechanism of imperfect three-dimensionally oriented attachment was revealed by the high-resolution transmission electron microscopy. The shallow donorlike defects as the legacy of aggregation-based growth were responsible for the observed high-temperature ferromagnetism (FM), further verifying the recent proposal. The solvothermal-treated strategy may not only offer an independent approach to directly tailor magnetic properties of advanced materials and devices at the nanoscale but also contribute to the sound understanding of the microscopic mechanism behind FM in DMSs.
INHIBITION OF TUMOR GROWTH BY POLYINOSINIC-POLYCYTIDYLIC ACID
Authors: Levy Hilton B. , Law Lloyd W. , Rabson Alan S.
Published: May 2006

The synthetic double-stranded RNA, polyinosinic-cytidylic acid, inhibits the growth of some tumors in mice. Two days after implantation of a reticulum cell sarcoma, a lymphatic lymphoma, a fibrosarcoma, two leukemias, and a human adenovirus 12-induced tumor, treatment of groups of mice resulted in decreased growth rates of the tumors and increased survival times of the animals. In the two tumors tested (the reticulum cell sarcoma and the adenovirus 12-induced tumor) initiation of treatment after the tumor was grown to moderate size caused a regression of the tumor. In the case of the reticulum cell sarcoma, the tumor had not reappeared in some of the animals two months after cessation of treatment.
DOSAGE COMPENSATION FOR ENZYME ACTIVITIES IN
Drosophila melanogaster
Authors: Seecof Robert L. , Kaplan William D. , Futch David G.
Published: May 2006

There are certain genes on the sex chromosome of
Drosophila
for which the female contains twice as many copies as the male. Some of the genes in this group produce the same phenotype in each sex despite the dosage difference and are said, therefore, to manifest dosage compensation. The structural genes for glucose-6-phosphate and 6-phosphogluconate dehydrogenases are located on the sex chromosome. We measured these enzyme activities in normal flies of each sex and in flies bearing fewer or extra copies of these genes.

Normal females (two-dose) had the same 6-phosphogluconate dehydrogenase activity as normal males (one-dose). One-dose females had reduced activity (0.61 of normal) and three-dose females or two-dose males had increased activity (about 1.3 of normal). Triploid females had the normal activity. Glucose-6-phosphate dehydrogenase activity responded similarly to gene dosage. Neither activity responded to changes in the dosage of the gene for the other. These results are compatible with an interpretation whereby each activity is compensated by the products of at least two regulatory genes. One of these regulatory genes is probably sex-linked; the others may be sex-linked or autosomal.
ON THE MECHANISM OF PEPSIN ACTION
Authors: Hollands T. Ralph , Fruton Joseph S.
Published: May 2006

The problem of the mechanism of pepsin action is considered in relation to recent data on the kinetics and specificity of the enzyme, as well as the finding, reported here, that pepsin exhibits a deuterium isotope effect in the cleavage of a peptide bond.

The kinetic parameters for the hydrolysis of the Phe(NO
2
)-Phe bond of Gly-Gly-Gly-Phe(NO
2
)-Phe-OMe by pepsin have been determined in H
2
O and in D
2
O. The finding of a significant deuterium isotope effect (
k
H2O
/
k
D2O
=
ca
. 2) supports the hypothesis that the catalytic mechanism of pepsin involves the participation, in the rate-limiting step, of a proton donor (probably an enzymic carboxyl group) in addition to an enzymic carboxylate group acting as a nucleophile.
SPIN-LABELED TRANSFER RNA
Authors: Hoffman Brian M. , Schofield Peter , Rich Alexander
Published: May 2006

The α-amino group of valyl-tRNA has been combined chemically with a nitroxide spin label through an amide linkage. This spin-labeled aminoacyl-tRNA has an electron paramagnetic resonance spectrum which reflects the mobility of the aminoacyl end of the tRNA molecule. The rate of tumbling of the spin label has been measured as a function of temperature and ionic strength. An abrupt transition in the nature of the motion occurs at a temperature which is sensitive to the ionic strength of the medium. This change in behavior of the aminoacylated spin label occurs at the same temperature as the midpoint of the optical density melting curves in dilute salt solutions. However, when denaturing agents such as dimethylsulfoxide or urea are added to the solution, the spin melting temperature is lower than the melting temperature as measured by the change in optical density. This suggests that under these conditions the local region of the aminoacyl end of the molecule denatures before the rest of the molecule is disrupted.
FURTHER EXTRACELLULAR DARWINIAN EXPERIMENTS WITH REPLICATING RNA MOLECULES: DIVERSE VARIANTS ISOLATED UNDER DIFFERENT SELECTIVE CONDITIONS
Authors: Levisohn Reuben , Spiegelman S.
Published: May 2006

Experiments are described which demonstrate that it is possible to isolate
in vitro
a variety of mutant RNA molecules which exhibit qualitatively distinguishable phenotypes. The results suggest that precellular evolution could have involved selective forces of previously unsuspected diversity and subtlety.

Suitable adjustment of the selective conditions leads to the isolation of variants optimally designed to compete successfully with the original viral nucleic acid. One of the properties that can be built into the variants is resistance to the presence of inhibitory analogues of the normal riboside triphosphates. Potentially, such variants could be used as antiviral devices
in conjunction
with the more usual chemotherapeutic agents.
SPECTRAL EVIDENCE FOR A NEW PHOTOREACTIVE COMPONENT OF THE OXYGEN-EVOLVING SYSTEM IN PHOTOSYNTHESIS
Authors: Knaff David B. , Arnon Daniel I.
Published: May 2006

On illuminating chloroplasts with “short-wavelength” monochromatic light that supports oxygen evolution, spectral evidence was obtained for a new photoreactive chloroplast component, provisionally designated C550, which shows a reversible decrease of absorbance with a maximum at 550 mμ. The light-induced absorbance changes in C550 have been separated from those due to cytochromes in the same spectral region.

The light-induced decrease of absorbance in C550 appears to be independent of temperature, persisting even at -189° and is therefore likely to be linked to the primary light reaction associated with oxygen evolution in photosynthesis.
THE ORIGIN OF THE NUCLEIC ACID BASES FOUND IN THE ROYAL JELLY OF THE HONEYBEE
Authors: Painter Theophilus S.
Published: May 2006

The discovery that the royal jelly of the honeybee contains large quantities of nucleic acids raises the question, “Where do these nucleic acids come from?” A review of pertinent literature strongly suggests that the same mechanism is involved as in the case of the extrachromosomal DNA of amphibian oocytes.
THE “9 + 1” PATTERN OF MICROTUBULES IN SPERMATOZOA OF
Mesostoma
(PLATYHELMINTHES, TURBELLARIA)
Authors: Henley Catherine , Costello D. P. , Thomas Mary Beth , Newton W. D.
Published: May 2006

The living spermatozoa of the flatworm
Mesostoma georgianum
have a sperm body about 100 μ long and 0.5 μ wide, and two motile free flagella,
ca.
200 μ long. In sections examined with the electron microscope, these flagella have the usual nine pairs of peripheral doublet microtubules and have a single central core unit which is connected to the A members of the doublets by spokelike structures. There are also short connections between the doublets and the flagellar membrane. In material negatively stained with phosphotungstic acid, the doublet microtubules seem to have very different elastic properties than the core; they tend to fall on the copper grids in coils of rather uniform diameter (2-4 μ), while the core is much more rigid and is often found extending alone, along a relatively straight course, for very long distances (up to 73 μ). After negative staining, the core has a striking appearance with a dense center around which are wound two hollow structures in a double helix of 45° pitch. The center-to-center distance of each gyre is approximately 650 Å, and the hollow structures are
ca.
180 Å in diameter.
ANALYSIS OF THE CHLORAMPHENICOL-SENSITIVE AND CHLORAMPHENICOL-RESISTANT STEPS IN THE INITIATION OF DNA SYNTHESIS IN
E. coli
B/r
Authors: Ward C. B. , Glaser D. A.
Published: May 2006

Two processes that are required for the initiation of a new round of bacterial DNA synthesis and which are blocked by low and high concentrations of chloramphenicol, respectively, have been examined in order to determine the cell age at which each of these processes occurs as a function of growth rate. The timing of these steps in the life cycle was determined by observing changes in the variation with cell age of the rate of DNA synthesis during growth in medium containing chloramphenicol of the desired concentration. For cell-doubling times ranging from 27 to 49 minutes, it was found that the step which is resistant to low concentrations of chloramphenicol occurs at the cell age at which a new round of DNA synthesis is initiated. The chloramphenicol-sensitive step was found to occur about 21 minutes before the start of rounds, independent of growth rate for doubling times between 27 and 49 minutes. For doubling of times 41 minutes or less, the chloramphenicol-sensitive processes occurred within five minutes after cell division.
RIGHT-SHIFT PROCESSES
Authors: Severo Norman C.
Published: May 2006

We present a class of Markov processes with multidimensional finite state space on which the infinitesimal transition movement is a shifting of one unit from one coordinate to some other to its right. We show how to represent the Kolmogorov forward equations as a triangular system.
Polytropic Montage: Ribosomes Examined in a Tissue Section
Authors: Hart Roger G. , Yoshiyama James M.
Published: May 2006

Electron micrographs of a variably titled specimen can be blended by computer to form an image of any selected specimen plane. Thus, one can examine a tissue section layer by layer with an effective depth of focus less than 30 Å. Ribosomes so observed in rat liver have some resemblances to isolated, tungsten-shadowed particles.
Decay of Fluorescence Emission Anisotropy of the Ethidium Bromide-DNA Complex Evidence for an Internal Motion in DNA
Authors: Wahl Ph. , Paoletti J. , Le Pecq J.-B.
Published: May 2006

Evidence for an internal oscillatory Brownian motion in the DNA helix is obtained from the measurement of the decay of the fluorescence emission anisotropy of the ethidium bromide-DNA complex. The amplitude of the oscillation is found to be equal to 35° and the relaxation time equal to 28 nanoseconds.
Cooperative Effects in Models of Steady-State Transport across Membranes, II. Oscillating Phase Transition
Authors: Hill Terrell L. , Chen Yi-der
Published: May 2006

A simple model for steady-state transport of a neutral molecule across a membrane is investigated in a preliminary way. In this model, there is a possible conformation change in each membrane unit which alters the access of the binding site for the transported molecule from one bath to the other. Thus, transport cannot be accomplished without a conformation change. Furthermore, we assume a cooperative interaction between nearest-neighbor membrane units in the same conformation. Then, with suitable rate constants and bath concentrations, and if the interaction energy is large enough, the membrane will oscillate back and forth between the two conformational phases, producing a surge of flux in each cycle. The period of the cycle depends on the times necessary to nucleate the two phase transitions.
Glycosphingolipids of Plasma Membranes of Cultured Cells and an Enveloped Virus (SV5) Grown in These Cells
Authors: Klenk Hans-Dieter , Choppin Purnell W.
Published: May 2006

Glycosphingolipids of rhesus monkey kidney (MK), bovine kidney (MDBK), and two lines of hamster kidney (BHK21-F and Hak) cells have been compared with those of parainfluenza (SV5) virions grow in these cells. There are qualitative and quantitative differences in the neutral glycolipids and gangliosides found in the various cells. Cells with a high neutral glycolipid content (MK and MDBK) contain little or no gangliosides, and those with a relatively high ganglioside content (BHK21-F and HaK) contain little neutral glycolipid. Glycosphingolipids are found predominantly in the plasma membranes. Neutral glycolipids of the host cell membrane are incorporated into the envelope of SV5 virions, but neither gangliosides nor protein-bound neuraminic acid are found in virions. The absence of neuraminic acid from the virion may be due to the action of viral neuraminidase.
Neurally Mediated Increase in Dopamine-β-Hydroxylase Activity
Authors: Molinoff Perry B. , Brimijoin Steven , Weinshilboum Richard , Axelrod Julius
Published: May 2006

The development of a sensitive and specific enzymatic assay for dopamine-β-hydroxylase has enabled us to measure the activity of this enzyme in several tissues where it has previously been measured. The administration of reserpine leads to an increase in dopamine-β-hydroxylase activity in the rat adrenal, heart, salivary gland, and in sympathetic ganglia. The increase in the heart is preceded by a small but significant fall. We have confirmed the increase in tyrosine hydroxylase which follows the administration of reserpine and have found that the activity of phenylethanolamine-
N
-methyltransferase also increases after administration of this drug. The activities of two enzymes not involved in the synthesis of catecholamines, monoamine oxidase and lactate dehydrogenase, are not affected by reserpine treatment. The rise of dopamine-β-hydroxylase activity in the sympathetic ganglia is blocked by surgical decentralization.
Electron Paramagnetic Resonance Studies of Spin-Labeled Hemoglobins and Their Implications to the Nature of Cooperative Oxygen Binding to Hemoglobin
Authors: Ho Chien , Baldassare Joseph J. , Charache Samuel
Published: May 2006

The spin label technique has been used to study human hemoglobins A, F, Zürich, and Chesapeake as a function of carbon monoxide saturation. The experimental results suggest that the changes in the electron paramagnetic resonance spectra of hemoglobin labeled with
N
-(1-oxyl-2,2,6,6-tetramethyl-4-piperidinyl)iodoacetamide depend on the state of ligation of more than one heme group. For those hemoglobins with full or large cooperative ligand binding (such as A, F, and Zürich), there is a lack of isosbestic points in the spectra as a function of CO saturation. However, for those hemoglobins with little or no cooperative ligand binding (such as Chesapeake and methemoglobins), there is a sharp set of isosbestic points. These findings confirm and extend the early work of McConnell and co-workers. The absence of a set of isosbestic points in those hemoglobins with full cooperative ligand binding is consistent with the sequential model of Koshland, Némethy, and Filmer for cooperative oxygen binding to hemoglobin. The present results, with hemoglobin variants having known amino acid substitutions, also focus on the importance of the interactions among the amino acid residues located at α
1
-β
2
or α
2
-β
1
subunit contacts for the functioning of hemoglobin as an oxygen carrier. In addition, the resonance spectra of the spin label are very sensitive to small structural variations around the heme groups in the β- or γ-chains where the labels are attached. The results of the spin label experiment are discussed in relation to recent findings on the mechanism of oxygenation of hemoglobin from the nuclear magnetic resonance studies of this laboratory and the x-ray crystallographic analysis of Perutz and co-workers.
Optical Activity of Biological Membranes: Scattering Effects and Protein Conformation
Authors: Schneider Allan S. , Schneider Mary-Jane T. , Rosenheck K.
Published: May 2006

The following question has recently arisen in the literature concerning the interpretation of the optical activity of biological membranes: do the characteristic spectral distortions observed for diverse membrane systems reflect some common and unique aspect of membrane architecture or are they the result of scattering effects owing to the particulate nature of membranous systems? We have confirmed the latter interpretation on the basis of the following experimental observations: (
a
) red blood cell membranes give a normal circular dichroism spectrum when scattering is reduced and (
b
) nonaggregated, nonmembranous helical proteins give distorted membranelike spectra when scattering is introduced. An improved estimate of secondary structure on the basis of undistorted spectra results in about 50 per cent α-helix for red blood cell membrane protein. In addition we conclude that the distortions in optical activity spectra offer no evidence in support of various proposed membrane models.