bluuebunny/crossref_metadata_2025 huggingface dataset:
Combined non‐linear laser imaging (two‐photon excitation fluorescence microscopy, fluorescence lifetime imaging microscopy, multispectral multiphoton microscopy) in cutaneous tumours: first experiences
Authors: De Giorgi V , Massi D , Sestini S , Cicchi R , Pavone FS , Lotti T
Published: January 2009

Background  Two‐photon excitation (TPE) fluorescence microscopy is a high‐resolution laser‐scanning imaging technique enabling deep imaging inside biological tissues. TPE microscopy has the triple advantage of offering high spatial resolution (250 nm radially, 800 nm axially), high penetration depth inside skin (200mm ), and low photodamage effects. Further, cells and extracellular matrix intrinsically contain a variety of fluorescent molecules (NADH, tryptophan, keratins, melanin, elastin, cholecalciferol and others), so that biological tissues can be imaged by TPE microscopy without any exogenous probe.

The time‐resolved analysis of the fluorescence signal, known as fluorescence lifetime imaging microscopy (FLIM), is an additional non‐invasive microscopy technique useful to characterize endogenous fluorescence species and their surrounding medium by measuring the mean lifetime of fluorescent emission. Finally, multispectral (MTPE) tissue imaging can also be used to identify different endogenous fluorescent species by measuring their two photon emission spectra. Those techniques offer functional information about the relative quantities of fluorescent molecules, which are correlated with tissue structure in physiological and pathological states.

Objective  We have decided to apply these three methods at the same time for cutaneous tumors in order to evaluate their possible future use.

Method  We have analyzed a melanoma and a basal cell carcinoma, with their surrounding healthy skin, to evaluate any difference in healthy skin and neoplasia.

The samples were excised during dermatological surgery, then cut, saving some healthy skin in both, to obtain a regular shape, allowing its positioning either with the skin surface parallel to the optical axis (horizontal optical sectioning), or perpendicular (vertical optical sectioning).

Conclusion  This first result demonstrates that FLIM is effective in discriminating healthy skin from MM, while MTPE is effective in discriminating healthy skin from BCC.

Conflicts of interest

None declared
Effect of commercial adjunct lactobacilli on biochemical and sensory characteristics of Iranian white‐brined cheese
Authors: HASHEMI MARYAM , AZAR MAHIN , TAGHI MAZLUMI MOHAMMAD
Published: January 2009

Iranian white‐brined cheese was made in open vats using commercial adjunct culture of Lactobacillus helveticus Lh.Bo2 in viable and freeze‐shocked (FS) forms. Biochemical and sensory characteristics of the trial cheese were studied during 2 months of ripening. Assessment of primary proteolysis by SDS‐PAGE and water soluble nitrogen for the trial cheese showed no or small differences throughout ripening. However, the experimental cheeses exhibited significantly greater rates of free amino group formation. Lipolysis as measured by total free fatty acid was consistently higher in cheese made with the FS adjunct culture. Expert panellists detected significant differences between the control and the experimental cheese.
Extracellular protease from Mucor pusillus: purification and characterization
Authors: NOUANI A , BELHAMICHE N , SLAMANI R , BELBRAOUET S , FAZOUANE F , BELLAL M M
Published: January 2009

Extracellular protease from Mucor pusillus was purified 18‐fold with 7.56% recovery by ion‐exchange chromatography and gel filtration. The enzyme was found to be monomeric in nature, having a molecular mass of 49 kDa. The enzyme acted optimally at 50°C and was stable in the temperature range 30–50°C. It was completely inactivated by heating for 30 min at 65°C. The optimum of activity for the purified extract was observed at milk CaCl2 concentration of 0.02 m and at milk pH of 5. These properties, except for temperature, were similar to those of rennet.
Swapping roles or swapping desks? When experienced practitioners become students on placement
Authors: Crisp Beth R. , Maidment Jane
Published: January 2009

The social work education literature on the preparation of students for their first practice learning placement, and the support needs of such students once in placement, tend to include implicit assumptions that the students being placed are novice practitioners, with little experience of working in social welfare agencies. Although there are some students for whom these assumptions are undoubtedly correct, another common phenomenon is that practice experience often leads to practitioners enrolling in professional degrees to qualify as a social worker. As credit for prior work experience in social welfare settings has only recently become possible for Australian social work students, we routinely work with aggrieved students who believe they should be exempted from placements, some of whom subsequently find the transition from experienced practitioner to student on placement somewhat difficult. This paper reports on a study which sought to explore the specific needs of experienced practitioners who become social work students on practice learning placements, with the aim of developing procedural recommendations for the placement and support of such students in the future. One of our findings was that several of the students continued to identify as practitioners, albeit in a different agency or programme from their normal place of employment, rather than take on the student identity. The implications of this for the development of practice learning opportunities for students who are experienced practitioners will be discussed.
Experimental Observations and Modelling of Compaction Bands in Oedometric Tests on High Porosity Rocks
Authors: Castellanza R. , Gerolymatou E. , Nova R.
Published: January 2009

Abstract:  Experimental results obtained in a series of displacement controlled oedometric tests on soft rocks are presented. Four different materials characterised by a high void ratio have been examined; three natural soft rocks and an artificial one. The materials under investigation were conchyliates stone, calcarenite, pumice stone and Gasbeton. In order to monitor the stress path as well, a soft oedometer ring was designed and constructed for the measurement of the radial stresses. The observed behaviour can be divided in three phases. After an initial phase in which the mechanical response is essentially elastic, a second phase starts, in which bonds are progressively broken, so that in the axial stress–strain curve a stress decrease is recorded and in some cases, a sort of ‘curl’ appears in the stress path. This is associated to the occurrence of strain non‐homogeneities in the form of compaction bands. In the final part of the experiment the axial stress increases exponentially and the stress path returns to be linear, as the one expected for a cohesionless material. The experimental behaviour is reproduced by means of an elastoplastic strain‐hardening/softening constitutive model and the occurrence of compaction bands is theoretically predicted.
The Impact of Social Amplification and Attenuation of Risk and the Public Reaction to Mad Cow Disease in Canada
Authors: Lewis Roxanne E. , Tyshenko Michael G.
Published: January 2009

Following the detection of bovine spongiform encephalopathy (BSE) in Canada, and subsequently in the United States, confidence in the safety of beef products remained high. Consumers actually increased their consumption of beef slightly after the news of an increased risk from mad cow disease, which has been interpreted as public support for beef farmers and confidence in government regulators. The Canadian public showed a markedly different reaction to the news of domestic BSE than the furious and panicked responses observed in the United Kingdom, Germany, and Japan. Using the social amplification of risk framework, we show that, while other countries displayed social amplification of risk, Canada experienced a social attenuation of risk. The attenuated reaction in Canada toward mad cow disease and increased human health risks from variant Creutzfeldt‐Jakob disease (vCJD) was due to the social context at the time when BSE was discovered domestically. Mortality, morbidity, and psychosocial impacts resulting from other major events such as severe acute respiratory syndrome (SARS), West Nile virus (WNV), and the U.S.‐Iraq war made the theoretical risks of BSE and vCJD a lower priority, reducing its concern as a risk issue.
ECG Evaluation of Ventricular Properties: The Importance of Cardiac Cycle Length
Authors: Extramiana Fabrice , Leenhardt Antoine , Maison‐Blanche Pierre
Published: January 2009

Ventricular repolarization properties are dependent on cardiac cycle length. The aim of this article is to emphasize the importance of taking into account heart rate influences on QT duration but also on current and future T‐wave morphology parameters. The relationship between QT interval duration and RR interval is a fundamental property of the myocardium that is impaired by the presence of channelopathies such as the LQTS or SQTS, but also by the presence of a cardiomyopathy. Assessing this property is also important when the individual QT/RR relationship is used for individual QT correction in the setting of evaluation of drugs' effect on QT duration. T‐wave descriptors such as the relative weight of the terminal part of the T‐wave, the amplitude of T‐wave apex and Principal Component Analysis parameters are also dependent on heart rate. Assessing ventricular repolarisation ECG parameters at different heart rates avoids the need for difficult rate‐correction and helps to better understand and characterize ventricular repolarisation properties.
Philips QT Interval Measurement Algorithms for Diagnostic, Ambulatory, and Patient Monitoring ECG Applications
Authors: Zhou Sophia H. , Helfenbein Eric D. , Lindauer James M. , Gregg Richard E. , Feild Dirk Q.
Published: January 2009

Background: Commonly used techniques for QT measurement that identify T wave end using amplitude thresholds or the tangent method are sensitive to baseline drift and to variations of terminal T wave shape. Such QT measurement techniques commonly underestimate or overestimate the “true” QT interval.

Methods: To find the end of the T wave, the new Philips QT interval measurement algorithms use the distance from an ancillary line drawn from the peak of the T wave to a point beyond the expected inflection point at the end of the T wave. We have adapted and optimized modifications of this basic approach for use in three different ECG application areas: resting diagnostic, ambulatory Holter, and in‐hospital patient monitoring. The Philips DXL resting diagnostic algorithm uses an alpha‐trimming technique and a measure of central tendency to determine the median QT value of eight most reliable leads. In ambulatory Holter ECG analysis, generally only two or three channels are available. QT is measured on a root‐mean‐square vector magnitude signal. Finally, QT measurement in the real time in‐hospital application is among the most challenging areas of QT measurement. The Philips real time QT interval measurement algorithm employs features from both Philips DXL 12‐lead and ambulatory Holter QT algorithms with further enhancements.

Results: The diagnostic 12‐lead algorithm has been tested against the gold standard measurement database established by the CSE group with results surpassing the industrial ECG measurement accuracy standards. Holter and monitoring algorithm performance data on the PhysioNet QT database were shown to be similar to the manual measurements by two cardiologists.

Conclusion: The three variations of the QT measurement algorithm we developed are suitable for diagnostic 12‐lead, Holter, and patient monitoring applications.
Automated QT Analysis That Learns from Cardiologist Annotations
Authors: Strachan Iain Guy David , Hughes Nicholas Peter , Poonawala Mustafa Hashim , Mason Jay W. , Tarassenko Lionel
Published: January 2009

Background: Reliable, automated QT analysis would allow the use of all the ECG data recorded during continuous Holter monitoring, rather than just intermittent 10‐second ECGs.

Methods: BioQT is an automated ECG analysis system based on a Hidden Markov Model, which is trained to segment ECG signals using a database of thousands of annotated waveforms. Each sample of the ECG signal is encoded by its wavelet transform coefficients. BioQT also produces a confidence measure which can be used to identify unreliable segmentations. The automatic generation of templates based on shape descriptors allows an entire 24 hours of QT data to be rapidly reviewed by a human expert, after which the template annotations can automatically be applied to all beats in the recording.

Results: The BioQT software has been used to show that drug‐related perturbation of the T wave is greater in subjects receiving sotalol than in those receiving moxifloxacin. Chronological dissociation of T‐wave morphology changes from the QT prolonging effect of the drug was observed with sotalol. In a definitive QT study, the percentage increase of standard deviation of QTc for the standard manual method with respect to that obtained with BioQT analysis was shown to be 44% and 30% for the placebo and moxifloxacin treatments, respectively.

Conclusions: BioQT provides fully automated analysis, with confidence values for self‐checking, on very large data sets such as Holter recordings. Automatic templating and expert reannotation of a small number of templates lead to a reduction in the sample size requirements for definitive QT studies.
PC‐Based ECG Waveform Recognition—Validation of Novel Software Against a Reference ECG Database
Authors: Dota Corina‐Dana , Edvardsson Nils , Skallefell Bo , Fager Gunnar
Published: January 2009

Background: PC‐based ECG measurements must cope with normal as well as pathological ECGs in a reliable manner. EClysis, a software for ECG measurements was tested against reference values from the Common Standards for Quantitative Electrocardiography (CSE) database.

Methods: Digital ECGs (12 leads, 500 Hz) were recorded by the CSE project. Data Set 3 contains reference values for 125 ECGs (33 normal and 92 pathological). Median values of measurements by 11 computer programs and by five cardiologists, respectively, refer to the earliest P and QRS onsets and to the latest P, QRS, and T offsets in any lead of a selected (index) beat. EClysis automatically measured all ECGs, without user interference.

Results: The PQRST points were correctly detected but in two ECGs with AV block II–III. The software was not designed to detect atrial activity in atrial fibrillation (n = 9) and flutter (n = 1). In one case of atrial fibrillation, atrial activity interfered with positioning of QRS and T offsets. Regression coefficients between EClysis© and CSE (software‐generated and human) were above 0.95 (P < 0.0001). The confidence intervals were 95% for the slope and the intercept of the regression lines.

Conclusions: The PC‐based detection and analysis of PQRST points showed a high level of agreement with the CSE database reference values.
The comparative study digestion and metabolism of nitrogen and purine derivatives in male, Thai, Swamp buffalo and Thai, Brahman cattle
Authors: JETANA Thongsuk , TASRIPOO Kringsak , VONGPIPATANA Cheerapath , KITSAMRAJ Suriya , SOPHON Sunpeth
Published: January 2009

Studies on in vivo digestion, rates of passages, metabolism of nitrogen, urinary purine derivative excretion and blood metabolites were carried out in Thai Brahman cattle and Thai swamp buffaloes (16 months old). The animals were fed mixed diets based on pineapple (Ananas comusus) waste silage containing urea‐N (NPN) and true protein from a concentrate (TP). The Brahman cattle (310 ± 15 kg) were heavier than the swamp buffaloes (195 ± 9.4 kg) and had higher dry matter (DM), organic matter (OM) and neutral detergent fiber (NDF) intakes when compared on the basis of their metabolic body weight (BW0.75), but these intakes did not differ significantly when the diets of each animal species were compared. The total tract, apparent digestibilities of dry matter (DM) and organic matter (OM) were not significantly different between the animal species when comparing the two types of diets. The NDF digestibility was significantly (P < 0.01) decreased in both animal species when fed the TP diet, but was significantly (P < 0.01) greater in cattle than in swamp buffaloes. The passage rate digesta k1 (P < 0.01) and the passage rate digesta k2 (through the caecum and proximal colon) (P < 0.03) were significantly slower, and the total mean retention time (TMRT) (P < 0.01) was significantly longer in swamp buffaloes when compared to Brahman cattle, but the transit time (TT) showed no difference (P = 0.07) between the animal species or the diets. The N intakes were not different in both animal species and diets, but urine‐N was greater (P < 0.05) in Brahman cattle than that in swamp buffaloes. Urine N and digestibility of N were significantly (P < 0.04) higher in animals fed the NPN diet than those fed the TP diet. Urinary purine derivatives (PD) and the creatinine (Cr) excretion of swamp buffaloes were significantly (P < 0.01) lower than those in Brahman cattle. Plasma urea‐N (BUN) concentration was significantly (P < 0.01) higher in swamp buffaloes than that in Brahman cattle, but plasma glucose and insulin concentrations were significantly (P < 0.01) higher in Brahman cattle than in swamp buffaloes. The concentrations of non‐esterified fatty acids (NEFA) were not significantly (P > 0.05) different in animals fed different diets. The present study demonstrated that Brahman cattle were better in fiber digestibility than swamp buffaloes at utilizing pineapple waste silage with both N sources.
Formation of zinc protoporphyrin IX in Parma‐like ham without nitrate or nitrite
Authors: WAKAMATSU Jun‐ichi , UEMURA Juichi , ODAGIRI Hiroko , OKUI Jun , HAYASHI Nobutaka , HIOKI Shoji , NISHIMURA Takanori , HATTORI Akihito
Published: January 2009

Zinc protoporphyrin IX (ZPP) is a characteristic red pigment in meat products that are manufactured without the addition of a curing agent such as nitrate or nitrite. To examine the effects of impurities such as mineral components in sea salt on the formation of ZPP, we manufactured Parmatype dry‐cured hams that were salted with refined salt or sea salt and examined the involvement of oxidation‐reduction potential (ORP) in the formation of ZPP. The content of ZPP was increased drastically after 40 weeks. Microscopic observation showed strong fluorescence caused by ZPP muscle fiber after 40 weeks. Conversely, heme content varied considerably during processing. ORP increased during processing. However, there was no obvious difference between ham salted with refined salt and that salted with sea salt. Therefore, it was concluded that impurities in sea salt were not involved in the formation of ZPP.
Effect of D‐mannitol on feed digestion and cecotrophic system in rabbits
Authors: HANIEH Hamza , SAKAGUCHI Ei
Published: January 2009

This study aimed to evaluate the effect of sugar alcohol as an energy source for cecal microbes on digestibility, cecotrophy (i.e. reingestion of microbial products of cecum, cecotrophs) and performance in rabbits. Thus, we fed rabbits an experimental diet that included 5% of D‐mannitol, and collected hard feces and cecotrophs to be analyzed for crude protein (CP), acid detergent fiber (ADF), ether extract (EE), crude ash (CA) and dry matter (DM). Cecotrophic behavior of the rabbits was also observed. Feeding D‐mannitol increased (P < 0.01) digestibility of ADF, resulting in a decrease (P < 0.05) in the concentration in hard feces. The increase (P < 0.05) in CP concentration was attributed to lower (P < 0.05) digestibility. D‐mannitol had a similar modulatory effect on CP and ADF concentrations in hard feces and cecotrophs. Accordingly, estimations of the proportion of nutrients recycled by cecotrophy to dietary intake (PR), obtained by the two calculation methods, showed an increase (P < 0.01) in PR of CP and a decrease (P < 0.05) in that of ADF. Daily weight gain and feed efficiency increased (P < 0.05) for D‐mannitol‐fed rabbits, while daily feed intake decreased (P < 0.05). These results suggest the possibility of using D‐mannitol as a stimulator of cecal microbial growth and cellulolytic activity, and therefore, improved rabbits performance.
Administrative Politics and the Public Presidency
Authors: BRANDICE CANES‐WRONE
Published: January 2009

As a field, we know exceedingly little about how presidents’ public relations affect administrative politics. For instance, when will presidents create new agencies to satisfy public concern about an issue? When does public opinion provoke presidents to fire officials? The dearth of scholarship on these sorts of questions is striking, particularly given the literature's emphasis on the importance of public relations to the presidency. I argue that we cannot fully understand bureaucratic politics without considering the impact of this development, which scholars call the “public presidency.” Furthermore, research on the public presidency has concentrated on legislative politics, which differ considerably from administrative politics. After delineating general claims, the author outlines theoretical and empirical considerations for two specific avenues of research.
Organizational Complexity and Coordination Dilemmas in U.S. Executive Politics
Authors: KRAUSE GEORGE A.
Published: January 2009

Modern scholarship on the institutional presidency has emphasized the formal mechanisms that presidents employ to obtain bureaucratic compliance. This literature emphasizes presidents' effective use of both expressed and implied constitutional powers. Unfortunately, little systematic inquiry has analyzed how extraconstitutional features of the executive branch limit the president's capacity for effective control over administrative agencies. This essay highlights three problems of organizational complexity relating to presidential control over the bureaucracy that merit greater attention from scholars of U.S. executive politics: (1) vertical coordination, (2) horizontal coordination, and (3) credible commitment. The author sketches out elements of a research agenda that examines presidential control over the bureaucracy in relation to each of these coordination problems. The basic implication of this essay is a simple one—failing to account for these organizational problems overstates the true capacity of presidential control over executive administration.
Back to the Future? Toward Revitalizing the Study of the Administrative Presidency
Authors: DURANT ROBERT
Published: January 2009

This article argues that despite the significant insights offered by prior research, assessments of the efficacy of the administrative presidency to date are both premature and in need of refocusing to comport with the realities of the American political system. In regard to prematurity, assessments must be withheld until four interrelated limitations of prior research are addressed. First, unlike early qualitative research on the topic, most recent research related to the administrative presidency has used neoclassical economics‐based or statistically sophisticated research designs that marginalize the implementation processes accompanying these efforts to advance presidential agendas. Second, assessments of the administrative presidency using this approach typically incorporate questionable assumptions. Third, typical criteria for assessing the administrative presidency fail to incorporate the realities of presidential decision making. Finally, most recent research fails to employ methodologies capable of incorporating these realities.
On the origin of eccentricities among extrasolar planets
Authors: Malmberg Daniel , Davies Melvyn B.
Published: January 2009

Most observed extrasolar planets have masses similar to, but orbits very different from, the gas giants of our Solar system. Many are much closer to their parent stars than would have been expected and their orbits are often rather eccentric. We show that some of these planets might have formed in systems much like our Solar system, i.e. in systems where the gas giants were originally on orbits with a semimajor axis of several au, but where the masses of the gas giants were all rather similar. If such a system is perturbed by another star, strong planet–planet interactions follow, causing the ejection of several planets while leaving those remaining on much tighter and more eccentric orbits. The eccentricity distribution of these perturbed systems is very similar to that of the observed extrasolar planets with semimajor axis between 1 and 6 au.
Millimetre observations of Pleiades stars: a lack of solar-analogue planetesimal discs at 100 Myr?
Authors: Greaves J. S. , Stauffer J. R. , Collier Cameron A. , Meyer M. R. , Sheehan C. K. W.
Published: January 2009

Solar analogues approximately 100 Myr old may have dusty debris from collisions within evolving cometary belts, and such remnant discs might also be associated with earlier stellar-spin braking. We observed at 1.2 mm wavelength a sample of 17 fast and slow rotators, mostly single K dwarfs, in the 100 Myr Pleiades cluster. No dust was detected for individual stars or the ensemble, so there are no cold massive debris discs nor any discernible relation of such distant material to stellar spin. The net limits from these data and our earlier far-infrared results imply that the typical Pleiades G/K dwarf has a relative disc-to-star luminosity ≲2 × 10-4. Collisional evolution models have predicted greater luminosities at the 108 yr epoch, for debris discs evolving out of a proto-solar nebula. This suggests that substantial primordial discs such as that of the Sun are not the norm amongst young solar analogues, or that dynamical interactions with giant planets can remove much of the comet belt by as early as 100 Myr.
The Local Dimension: a method to quantify the Cosmic Web
Authors: Sarkar Prakash , Bharadwaj Somnath
Published: January 2009

It is now well accepted that the galaxies are distributed in filaments, sheets and clusters, all of which form an interconnected network known as the Cosmic Web. It is a big challenge to quantify the shapes of the interconnected structural elements that form this network. Tools like the Minkowski functionals which use global properties, though well-suited for an isolated object like a single sheet or filament, are not suited for an interconnected network of such objects. We consider the Local Dimension D, defined through N(R) =A RD, where N(R) is the galaxy number count within a sphere of comoving radius R centred on a particular galaxy, as a tool to locally quantify the shape in the neighbourhood of different galaxies along the Cosmic Web. We expect D∼ 1, 2 and 3 for a galaxy located in a filament, sheet and cluster, respectively. Using LCDM N-body simulations, we find that it is possible to determine D through a power-law fit to N(R) across the length-scales 2 to 10 Mpc for ∼33 per cent of the galaxies. We have visually identified the filaments and sheets corresponding to many of the galaxies with D∼ 1 and 2, respectively. In several other situations, the structure responsible for the D value could not be visually identified, either due to it being tenuous or due to other dominating structures in the vicinity. We also show that the global distribution of the D values can be used to visualize and interpret how the different structural elements are woven into the Cosmic Web.
Preferences for Oral Health States in a US Community‐Dwelling Functionally Impaired Older Adult Population: 2000–2001
Authors: Thierer Todd , Friedman Bruce
Published: January 2009

Objectives:To determine whether and how much time in a state of ill oral health an older person would be willing to trade for optimal oral health. Methods:This is a cross‐sectional observational study of 76 subjects (52 female, 24 male) ages 47–93 (mean 75.2) recruited from a Medicare demonstration. Subjects had to need or receive help with 2+ activities of daily living (ADLs) or 3+ instrumental ADLs plus had to have had recent significant healthcare services use. A Time Trade‐Off (TTO) approach was used. TTO utility is defined as the amount of symptom‐free time (i.e., the optimal oral health state) divided by the amount of time with symptoms (either their current oral health state or the worst imaginable oral health state, depending on the scenario), at the point of indifference (the point past which the person is unwilling to trade additional life expectancy). Results:When starting from their current oral health state, 39% of the subjects were willing to exchange time resulting in a shorter life with optimal oral health. Theywere willing to trade 14.0 months of life on average and valued each year in their current oral health state as 91% of a year in optimal oral health. When starting in the poorest oral health state, 79% of the subjects were willing to accept a shorter life. They were willing to trade 33.7 months of life on average, and valued the poorest state as worth 79% of a year in optimal oral health. Conclusions:Dentists should take into consideration this group's preference for optimal oral health.
Infection Control Measures Among Senior Dental Students in Rio de Janeiro State, Brazil
Authors: de Souza Rogério A. , Namen Fátima M. , Jr Joāo Galan , Vieira Cristine , Sedano Heddie O.
Published: January 2009

Objectives:The aim of this study was to verify the practices and attitudes of senior dental students about infection control procedures. Methods:A cross‐sectional survey was performed during the 1st semester of 2003. Open‐ and close‐ended questions were given to 196 students in 6 universities. Results:Overall, 90.8% of students had been vaccinated for hepatitis B. Only 25.0% have been assessed for anti‐HBs. A total of 99.5% students reported always using gloves for all procedures. Eye protection were always used by 84.2% of students, and all the students used face masks for all procedures. Caps or hair covers were used by 92.3% of students and 87.8% reported no objection to treating patients with infectious diseases. Among instructors, the students observed that 60.2% of them did not use gloves for all procedures, 43.4% of those didn't change gloves between patients. Conclusions:These results address the need for an improved quality assurance, in order for the students and faculty to improve their practices and attitudes on infection control measures.
Spatially Resolved Streaming Potentials of Human Intervertebral Disk Motion Segments Under Dynamic Axial Compression
Authors: Iatridis James C. , Furukawa Masaru , Stokes Ian A. F. , Gardner-Morse Mack G. , Laible Jeffrey P.
Published: January 2009

Intervertebral disk degeneration results in alterations in the mechanical, chemical, and electrical properties of the disk tissue. The purpose of this study is to record spatially resolved streaming potential measurements across intervertebral disks exposed to cyclic compressive loading. We hypothesize that the streaming potential profile across the disk will vary with radial position and frequency and is proportional to applied load amplitude, according to the presumed fluid-solid relative velocity and measured glycosaminoglycan content. Needle electrodes were fabricated using a linear array of Ag∕AgCl micro-electrodes and inserted into human motion segments in the midline from anterior to posterior. They were connected to an amplifier to measure electrode potentials relative to the saline bath ground. Motion segments were loaded in axial compression under a preload of 500N, sinusoidal amplitudes of ±200N and ±400N, and frequencies of 0.01Hz, 0.1Hz, and 1Hz. Streaming potential data were normalized by applied force amplitude, and also compared with paired experimental measurements of glycosaminoglycans in each disk. Normalized streaming potentials varied significantly with sagittal position and there was a significant location difference at the different frequencies. Normalized streaming potential was largest in the central nucleus region at frequencies of 0.1Hz and 1.0Hz with values of approximately 3.5μV∕N. Under 0.01Hz loading, normalized streaming potential was largest in the outer annulus regions with a maximum value of 3.0μV∕N. Correlations between streaming potential and glycosaminoglycan content were significant, with R2 ranging from 0.5 to 0.8. Phasic relationships between applied force and electrical potential did not differ significantly by disk region or frequency, although the largest phase angles were observed at the outermost electrodes. Normalized streaming potentials were associated with glycosaminoglycan content, fluid, and ion transport. Results suggested that at higher frequencies the transport of water and ions in the central nucleus region may be larger, while at lower frequencies there is enhanced transport near the periphery of the annulus. This study provides data that will be helpful to validate multiphasic models of the disk.
A Field Experiment to Test the Importance of Estuaries for Chinook Salmon (Oncorhynchus tshawytscha) Survival: Short-Term Results
Authors: Macdonald J. Stevenson , Levings Colin D. , McAllister Carey D. , Fagerlund U. H. M. , McBride J. R.
Published: January 2009

In late April of 1983, 1984, and 1985, 140 000 marked chinook salmon (Oncorhynchus tshawytscha) smolts (2–4 g) were transported by helicopter from Quinsam Hatchery to four release sites near Campbell River, B.C. (river, estuarine, transition, and marine), in an experiment to test the importance of estuarine residency to chinook survival. At the marine site, fish were released directly into seawater. These fish had high cortisol levels and larger interrenal nuclear diameters than those at the estuarine site, indicating a transitory stress response to seawater exposure. Nevertheless, there was little direct mortality due to stress or osmoregulatory shock at any of the release sites. Marine-released fish were exposed to more bird and fish predators. Mortality of caged chinook was higher at the marine location than at all other sites despite seawater challenge tests indicating that the chinook were smolted and "ready for sea." Beach seine data obtained biweekly for 4 mo after the releases showed that fish released directly into marine waters rarely dispersed to the Campbell River estuary. Fish released immediately adjacent to the mouth of the estuary (transition zone) had the widest immediate dispersal pattern, with many of them returning to the estuary. Estuarine zone fish displayed the most restricted distribution. Fish released to the river and estuary remained in the sampling area for a longer period (34–47 d) than those released in the marine or transition zone (20–23 d).
Scaled Chrysophytes (Chrysophyceae) as Indicators of pH in Sudbury, Ontario, Lakes
Authors: Dixit Sushil S. , Dixit Aruna S. , Evans R. Douglas
Published: January 2009

Surface sediment chrysophytes (Chrysophyceae) of 30 Sudbury, Ontario, lakes were analyzed to investigate the relationship of these algal microfossils with the limnological characteristics of the study lakes. The distribution of the majority of common chrysophyte taxa is correlated closely with lake water pH, pH-related factors, or both. Chrysodidymus synuroideus, Synura echinulata, Mallomonas hamata, M. acaroides var. muskokana, and Chrysosphaerella longispina appear to be indicators of strongly to moderately acidic waters whereas M. pseudocoronata and M. caudata are indicators of circumneutral to alkaline waters. Using multiple regression of pH indicator chrysophyte assemblages against the measured lake pH, a calibration equation was developed to compute chrysophyte-inferred pH. Chrysophyte-inferred pH values were closely related with measured lake water pH (r2 = 0.74). The study indicates that in the absence of historical pH data, stratigraphic analysis of scaled chrysophytes would provide useful information about the history of lake acidification in the Sudbury area. There is some indication that high metal concentrations, in addition to pH, may influence chrysophycean species distribution in acidic lakes.
An Evaluation of Lake Trout (Salvelinus namaycush) Hooking Mortality in the Upper Great Lakes
Authors: Loftus Andrew J. , Taylor William W. , Keller Myrl
Published: January 2009

Investigation of lake trout (Salvelinus namaycush) hooking mortality was conducted in Lakes Michigan, Huron, and Superior during 1984 and 1985. Fish were caught and handled by charterboat operators and sport fishermen. Mortality was estimated by returning hooked fish to the lake after tethering them to a line–buoy system. Overall hooking mortality was estimated to be 14.9% (95% C.I. = 7.4–25.7). Significantly higher mortalities occurred in fish that were not discovered to have been hooked and in fish of smaller size classes. In addition, lake trout that were hooked in internal regions produced a mortality of 71.4% whereas those hooked in the upper or lower jaw had a mortality of 6.9%. The depth from which the fish was angled, the temperature differential from this depth to the surface, gear type, and handling times had no significant impact on survival. These results support the use of size limits, creel limits, and season restrictions as effective methods to reduce sport fishing mortality of lake trout.
Seasonal Ingestion Rates of Pontopareia hoyi (Amphipoda) in Lake Ontario
Authors: Dermott Ronald , Corning Karl
Published: January 2009

Pontoporeia hoyi in Lake Ontario do not feed continually, their guts averaging 48% full. Feeding intensity of immature amphipods follows the changes in percent of carbon of the settling organic matter, being highest during the late spring and fall. Gut filling time ranged from 6.7 to 3.4 h at 5 and 14 °C Daily ingestion of organic matter ranged from 0.05 g∙m−2∙d−1 at the deepest station sampled (125 m) to 0.17 g∙m−2∙d−1 at the shallowest (35 m). The organic matter ingested by the Pontoporeia present represented 8.8 and 7.9% of the average daily rate of organic matter deposited at these two stations respectively. The lakewide estimate of the organic matter consumed by Pontoporeia in Lake Ontario was about 19 g∙m−1 during 1981 and 21 g∙m−2∙yr−1 during 1982.
Fish Species Richness in Relation to Lake Area, pH, and Other Abiotic Factors in Ontario Lakes
Authors: Matuszek J. E. , Beggs G. L.
Published: January 2009

Survey data from 2931 Ontario lakes were analyzed to determine how fish species richness was empirically related to a set of 19 physical and chemical limnological variables. Lake area was the dominant factor, explaining 18% of the variation in species number. Total aluminum, latitude, dissolved organic carbon, and elevation together explained an additional 16%. The strong relationship between species number and lake area was quantified using lakes with pH [Formula: see text] and then applied to ail the surveyed lakes to estimate species number. Deviations from the expected values indicated that species number decreased with decreasing pH below 6.0, resulting in significantly fewer species in lakes with pH < 6.0. In the subset of lakes with pH < 6.0, pH alone explained 21% of the variation in species number; elevation, lake area, and dissolved organic carbon together explained an additional 20%. Interactions between pH and lake area were identified; lake size decreased significantly both at low pH (<6.8) and at high pH [Formula: see text]. An understanding of these interactions was essential in explaining the relative roles of pH and lake area in determining species richness.
Growth and Feeding Responses of Male versus Female Yellow Perch (Perca flavescens) Treated with Estradiol-17β
Authors: Malison Jeffrey A. , Kayes Terrence B. , Wentworth Bernard C. , Amundson Clyde H.
Published: January 2009

In yellow perch (Perca flavescens) (initially 13–16 g total weight) fed to satiation (3.0–3.5% of body weight per day), estradiol-17β (E2) at 15 μg/g diet stimulated weight gain and food consumption of both sexes but did not influence food conversion efficiency (FCE), as measured by weight gain of fish per weight of food consumed. Females fed to satiation gained more weight, consumed more food, and had higher FCE than males. In perch fed a restricted ration (1.2% of body weight per day), the differences between the sexes in weight gain were reduced and due entirely to differences in FCE, and weight gain was not improved by E2. Spatial segregation or integration of the sexes had no influence on sex-related growth patterns in perch fed either the satiation or restricted ration. Carcass composition of perch treated for 84 d with E2 at 2, 20, or 50 μg/g diet did not differ from that of controls. These data indicate that (1) estrogens promote growth in yellow perch by stimulating food consumption, (2) female perch outgrow males because of both greater food consumption and higher FCE, and (3) growth differences between the sexes are not a consequence of intersexual competition for food.
Distribution and Abundance of the Toxic Dinoflagellate Gonyaulax excavata in the Bay of Fundy
Authors: Martin Jennifer L. , White Alan W.
Published: January 2009

Water samples were collected for five consecutive summers (1980–84) in the Bay of Fundy at the surface and at 5 m to examine the distribution patterns of the motile stages of the toxic dinoflagellate Gonyaulax excavata, which has caused shellfish toxicity in this area for years, as well as occasional fish kills. In 1980 and 1981, 128 and 122 stations were sampled, respectively, and 84 and 41% of the samples contained G. excavata cells. Further sampling in 1982–84 was reduced to areas where most cells were observed in previous years. During this period, G. excavata was observed in 91–100% of the locations sampled. Despite variations in abundance of G. excavata cells from year to year, the overall distribution patterns were similar. The highest concentrations of cells occurred in the south-central and southwestern portions of the Bay in the area bounded by the Quoddy Region and Saint John, New Brunswick, and Digby, Nova Scotia. The distribution of various life cycle stages (plahozygotes, vegetative duplets, and sexually fusing cells) was similar to that of individual motile cells, suggesting that the annual blooms in this region behave as one large population. Few or no G. excavata cells were found at the head of the Bay or at the seaward approaches. Results suggest the prevailing circulation in the Bay and the presence of tidal fronts are dominant factors in retaining G. excavata and its life cycle stages in the south-central and southwestern portion of the Bay and that this accounts for its perennial occurrence in this area.
Patterns in Biomass and Cover of Aquatic Macrophytes in Lakes: Test with Florida Lakes
Authors: Canfield Jr. Daniel E. , Duarte Carlos M.
Published: January 2009

Data from 69 Florida lakes were used to test 15 empirical models that were developed from a worldwide data base to describe the biomass and cover of aquatic macrophytes in lakes. Ten of the models failed to provide useful predictions in Florida because the models did not adequately reflect the limnological characteristics of Florida lakes. Submerged and emergent biomass in the Florida lakes was predicted by the models that estimated these parameters from the areal cover of submerged and emergent vegetation. Total macrophyte cover in Florida lakes could be predicted from a model based on lake size, annual irradiance at the surface, and the mean annual irradiance within the mean depth of the lake. Even the best models, however, overestimated submerged plant biomass and cover in highly colored (>400 Pt–Co units) lakes and lakes with steep (slope >15%) littorals. This suggests that the influence of light (quantity and quality) and littoral slope on the abundance of aquatic macrophytes needs additional research before improved empirical models can be developed for lakes located in limited geographic regions.
Impact of Heavy Metals on Insect Communities in Streams: A Comparison of Observational and Experimental Results
Authors: Clements Williams H. , Cherry Donald S. , Cairns Jr. John
Published: January 2009

This research compares effects of heavy metals on macroinvertebrate communities in outdoor experimental streams with those observed at impacted field sites. Natural assemblages of aquatic macroinvertebrates were established on substrate-filled trays which were then transferred to outdoor stream mesocosms. Exposure of these communities to low levels of copper and zinc (target concentration = 12 μg/L) significantly reduced the number of taxa, number of individuals, and abundance of most dominant taxa within 4 d. After 10 d, control streams were dominated by Ephemeroptera and Tanytarsini chironomids, whereas treated streams were dominated by Hydropsychidae and Orthocladiini. Responses of benthic communities to metals observed at the Clinch River (Russell Co., Virginia), a system impacted by copper and zinc, were similar to those in experimental streams. Ephemeroptera and Tanytarsini, which comprised 38–46% of the macroinvertebrate community at upstream reference stations, were significantly reduced at all effluent sites. As in treated experimental streams, impacted stations were dominated by Hydropsychidae and Orthocladiini. The similarity of our experimental results to those obtained from Clinch River field sites suggests that outdoor stream mesocosms may be employed to predict macroinvertebrate community responses to heavy metals.
The Mansouri–Sexl formalism for the Michelson–Morley experiment in nonvacuum media
Authors: Sfarti A
Published: January 2009

In the present paper, we construct the complete Mansouri–Sexl formalism for the Michelson–Morley and Kennedy–Thorndike experiments executed in a refractive medium by extending their previous formalism derived for vacuum-based experiments. This is an important step since we will show that the experiments executed in a refractive medium give new possibilities for testing for Lorentz violations. In a previous paper, we developed the correct nonparametric treatment under the framework of special relativity, so no violation testing was possible. On the other hand, a parameterized theory, like that of Mansouri–Sexl is the standard way of testing for Lorentz symmetry violations. While other parameterized theories, like the Standard Model extension (SME) emerged in the late 1990s The Mansouri–Sexl formalism is still very much employed in experiments due to its relative simplicity and its lower number of parameters (three) versus the 19 parameters used in SME. This is why we are undertaking the novel step of constructing the corresponding Mansouri–Sexl formalism. Yet another novel attempt is to describe an unprecedented variation of the Kennedy–Thorndike experiment employing different refractive media for the interferometer arms. We will also demonstrate the advantages of deferring the expansion of the Mansouri–Sexl parameters a, b, and d as long as possible, thus obtaining a higher level of precision in deriving the violations.PACS No.: 03.30.+p
Determining the sp2/sp3 bonding concentrations of carbon films using X-ray absorption spectroscopy
Authors: Hamilton T , Wilks R G , Yablonskikh M V , Yang Q , Foursa M N , Hirose A , Vasilets V N , Moewes A
Published: January 2009

The sp2 bonding concentrations of nitrogen-doped amorphous carbon samples and nanodiamond films were determined from their soft X-ray absorption spectra. The amorphous carbon (a-C) samples were deposited under atmospheres of varying nitrogen concentrations onto polytetrafluoroethylene (PTFE) polymer and silicon substrates. The nanodiamond films were synthesized on silicon substrates in a CH4/H2 gas mixture by microwave plasma chemical vapour deposition. The sp2 bonding concentrations in the a-C films (deposited on PTFE substrates) increase from 74% to 93% as nitrogen doping increases, with a step-like increase in sp2 fraction when nitrogen concentrations in the films exceed 27%. The a-C films on silicon substrates display the same trend of increasing sp2 concentration as a function of greater nitrogen concentration. Nanodiamond deposition conditions, such as bias voltage and methane concentration, affect the purity of the film. Our analysis reveals sp2 bonding concentrations in these samples ranging from a few percent to 11%.PACS Nos.: 78.70.Dm, 61.10.Ht, 61.46.+w, 81.05.Uw