bluuebunny/crossref_metadata_2025 huggingface dataset:
Orchestration of the inflammatory response in ischemia‐reperfusion injury
Authors: Iida Haruyasu , Schmeichel Ann M. , Wang Yanping , Schmelzer James D. , Low Phillip A.
Published: June 2007

Abstract  Ischemia to nerve can cause fiber degeneration and reperfusion following ischemia [ischemia‐reperfusion (IR)] adds the additional insult of an inflammatory response and oxidative injury. Limited information is available on the molecular mediators and their endoneurial targets. In this study, using a highly reproducible animal model of IR injury to nerve and selective immunolabeling methods [for nuclear factor kappa B (NF‐κB), intercellular adhesion molecule‐1 (ICAM‐1), cytokines, and inflammatory cells] over an expanded time frame, we evaluated the temporal pattern and localization of mediators of the inflammatory response. Sixty rats were used. Nine groups (N = 6 each) underwent complete hind limb ischemia for 4 h, followed by reperfusion durations of 0, 3, 12, 24, and 48 h, and 7, 14, 28, and 42 days. One group underwent sham operation (N = 6). The earliest change was ICAM‐1 expression in the microvessel (endothelial cell) followed almost immediately by NF‐κB activation with axonal expression (24 and 48 h), followed by endoneurial edema and ischemic fiber degeneration (7 and 14 days). Granulocytic infiltration was followed by endoneurial infiltration of mononuclear phagocytes (14 days), expression of interleukin 6 (IL‐6) (microvessels), and subsequent Schwann cell NF‐κB expression. Granulocytes, tumor necrosis factor alpha, and IL‐6–positive cells were observed primarily within the epineurium. IR results in changes in a number of interacting networks of targets and inflammatory mediators. NF‐κB activation has a central orchestrating role involving both the axon and the Schwann cell in effecting the inflammatory response.
Civil Service Law in the People’s Republic of China: A Return to Cadre Personnel Management
Authors: Chan Hon S. , Suizhou Edward Li
Published: June 2007

Despite the outward appearance of depoliticization, the civil service in China today is actually being repoliticized. This paper compares the 1993 Provisional Regulations on State Civil Servants with the Civil Service Law approved by the Standing Committee of the National People’s Congress of the People’s Republic of China (PRC) in April 2005. The 2005 reform formalized what had been a historical pattern—the Communist Party holds tight control over leadership change and management at various levels. The Civil Service Law has turned the Communist Party of China into a political institution that has become the source of both civil service empowerment and control. Although civil service reform in China differs markedly from approaches adopted elsewhere, China is clearly expanding its political control to ensure greater leverage over the bureaucracy. In this regard, China is in line with the global trend. That said, civil service reform in China has focused on structural elements and formal reorganizations, whereas most industrialized democracies have engaged in a dialectic between individualist and corporate responses to managerial questions. An understanding of the Chinese ability to adopt reforms—while strengthening its traditional hold—provides key perspectives not only on the world’s largest nation and a rapidly emerging force in global political and economic relationships but also on the Chinese experience with important public sector reforms that have occurred in many other countries over recent decades.
Recommendations Forestalled or Forgotten? The National Commission on the Public Service and Presidential Appointments
Authors: Light Paul C.
Published: June 2007

Nearly two decades after the first Volcker Commission issued its report on the federal public service, the presidential appointment and confirmation process remains long, cumbersome, intensive, and embarrassing. As the evidence presented in this essay suggests, the process may attract people who are motivated more by personal rewards than by the intrinsic value of public service. Although recent administrations have displayed little enthusiasm for reforming the federal appointment process, the best hope for change may reside in future presidents’ desire to assert tight political control over executive departments.
Coercion versus Choice: Citizen Evaluations of Public Service Quality across Methods of Consumption
Authors: Brown Trevor
Published: June 2007

Treating all respondents to citizen satisfaction surveys as “customers” risks misinterpreting the findings and misguiding managerial decision making. Citizen evaluations of the quality of public services are likely to vary based on whether citizens have a direct or indirect relationship to the service. Furthermore, citizens are likely to rate services differently based on whether they consume the services as a result of coercion or choice, although the quality of the interaction shapes the impact of the type of interaction. Based on a series of empirical analyses, this paper demonstrates that recipients who have superior‐quality interactions with providers are likely to report high ratings for elective services, whereas citizens who have poor‐quality interactions are likely to report low ratings for coercive services. In this way, the quality of the interaction influences citizens’ predispositions to rate services high or low based on whether they consume the service by choice or coercion.
Experience of the Management of Ventricular Tachycardia by Percutaneous Transluminal Coronary Angioplasty
Authors: MORGAN JOHN M. , BERNARDI GUGLIELMO , ROWLAND EDWARD , RICKARDS ANTHONY
Published: June 2007

Three patients with ischemic heart disease in whom ventricular arrhythmia was thought to be the consequence of acute myocardial ischemia underwent percutaneous transluminal coronary angioplasty. This approach was not consistently successful. The mechanisms of ventricular tachyarrhythmia in ischemic heart disease and the rationale for the treatment of ventricular arrhythmia by revascularization remain unclear. The role of percutaneous transluminal coronary angioplasty needs to be defined in this context.
Variability in feeding ecology of a South American cichlid: a reason for successful invasion in mediterranean‐type rivers?
Authors: Ribeiro F. , Orjuela R. L. , Magalhães M. F. , Collares‐Pereira M. J.
Published: June 2007

Abstract –  Ecological attributes behind the success of the South American cichlid Australoheros facetus in mediterranean‐type rivers remain unclear. This study addresses this issue, by analysing its abundance and feeding patterns in the lower Guadiana drainage (Portugal), during the dry season of 2003. Despite slight spatial variations in abundance and individual size, A. facetus seemed well established in the Guadiana, Vascão and Ardila rivers. No seasonal or size‐related changes in feeding intensity were found, but the diet changed across rivers, over time and throughout ontogeny. Feeding seemed highly generalist, with fish apparently reacting to both spatial and temporal changes in food supply and tending to use the most abundant and easily accessible food items. Overall prey breadth was broad relative to that of other native and non‐native species. It is suggested that a generalist feeding strategy may play a significant role in the establishment of non‐native fish in mediterranean‐type rivers.
Saposin B mobilizes lipids from cholesterol‐poor and bis(monoacylglycero)phosphate‐rich membranes at acidic pH
Authors: Remmel Natascha , Locatelli‐Hoops Silvia , Breiden Bernadette , Schwarzmann Guenter , Sandhoff Konrad
Published: June 2007

Sphingolipid activator proteins (SAPs), GM2 activator protein (GM2AP) and saposins (Saps) A–D are small, enzymatically inactive glycoproteins of the lysosome. Despite of their sequence homology, these lipid‐binding and ‐transfer proteins show different specificities and varying modes of action. Water‐soluble SAPs facilitate the degradation of membrane‐bound glycosphingolipids with short oligosaccharide chains by exohydrolases at the membrane–water interface. There is strong evidence that degradation of endocytosed components of the cell membrane takes place at intraendosomal and intralysosomal membranes. The inner membranes of the lysosome differ from the limiting membrane of the organelle in some typical ways: the inner vesicular membranes lack a protecting glycocalix, and they are almost free of cholesterol, but rich in bis(monoacylglycero)phosphate (BMP), the anionic marker lipid of lysosomes. In this study, we prepared glycosylated Sap‐B free of other Saps by taking advantage of the Pichia pastoris expression system. We used immobilized liposomes as a model for intralysosomal vesicular membranes to probe their interaction with recombinantly expressed Sap‐B. We monitored this interaction using SPR spectroscopy and an independent method based on the release of radioactively labelled lipids from liposomal membranes. We show that, after initial binding, Sap‐B disturbs the membrane structure and mobilizes the lipids from it. Lipid mobilization is dependent on an acidic pH and the presence of anionic lipids, whereas cholesterol is able to stabilize the liposomes. We also show for the first time that glycosylation of Sap‐B is essential to achieve its full lipid‐extraction activity. Removal of the carbohydrate moiety of Sap‐B reduces its membrane‐destabilizing quality. An unglycosylated Sap‐B variant, Asn215His, which causes a fatal sphingolipid storage disease, lost the ability to extract membrane lipids at acidic pH in the presence of BMP.
Mechanism of the ring contraction process in vitamin B12 biosynthesis by the anaerobe Propionibacterium shermanii under aerobic conditions
Authors: Iida Katsumi , Ohtaka Kuniaki , Kajiwara Masahiro
Published: June 2007

The mechanism of the ring contraction process during vitamin B12 biosynthesis by the anaerobe Propionibacterium shermanii was investigated under both aerobic and anaerobic conditions by means of feeding experiments with δ‐amino[1‐13C]levulinic acid (a biosynthetic intermediate of tetrapyrrole) and δ‐amino[1‐13C,1,1,4‐18O3]levulinic acid in combination with 13C‐NMR spectroscopy. We showed that the characteristic mechanism of the ring contraction process (the generation of precorrin‐3x from formation of the γ‐lactone from the ring A acetate group at C1 and hydroxylation at C20 by molecular oxygen catalyzed by CobG, and the migration of ring D by cleavage of the carbon–oxygen bond at C1 of precorrin‐3x) in the aerobe Pseudomonas denitrificans was not seen in P. shermanii under aerobic conditions, and the mechanism of the ring contraction process in P. shermanii was the same irrespective of the presence or absence of oxygen.
The colour selection of distant galaxies in the UKIDSS Ultra Deep Survey Early Data Release
Authors: Lane K. P. , Almaini O. , Foucaud S. , Simpson C. , Smail Ian , McLure R. J. , Conselice C. J. , Cirasuolo M. , Page M. J. , Dunlop J. S. , Hirst P. , Watson M. G. , Sekiguchi K.
Published: June 2007

We investigate colour selection techniques for high-redshift galaxies in the UKIRT Infrared Deep Sky Survey (UKIDSS) Ultra Deep Survey Early Data Release (UDS EDR). Combined with very deep Subaru optical photometry, the depth (KAB= 22.5) and area (0.62 deg2) of the UDS EDR allow us to investigate optical/near-infrared selection using a large sample of over 30 000 objects. By using the B−z′, z′−K colour–colour diagram (the BzK technique) we identify over 7500 candidate galaxies at z > 1.4, which can be further separated into passive and star-forming systems (pBzKs and sBzKs respectively). Our unique sample allows us to identify a new feature not previously seen in BzK diagrams, consistent with the passively evolving track of early-type galaxies at z < 1.4. We also compare the BzK technique with the R−K colour selection of extremely red objects (EROs) and the J−K selection of distant red galaxies (DRGs), and quantify the overlap between these populations. We find that the majority of DRGs at these relatively bright magnitudes are also EROs. Since previous studies have found that DRGs at these magnitudes have redshifts of z∼ 1, we determine that these DRGs/EROs have spectral energy distributions consistent with being dusty star-forming galaxies or active galactic nuclei at z < 2. Finally, we observe a flattening in the number counts of pBzK galaxies, similar to other studies, which may indicate that we are sampling the luminosity function of passive z > 1 galaxies over a narrow redshift range.
Compensating Enthalpic and Entropic Changes Hinder Binding Affinity Optimization
Authors: Lafont Virginie , Armstrong Anthony A. , Ohtaka Hiroyasu , Kiso Yoshiaki , Mario Amzel L. , Freire Ernesto
Published: June 2007

A common strategy to improve the potency of drug candidates is to introduce chemical functionalities, like hydrogen bond donors or acceptors, at positions where they are able to establish strong interactions with the target. However, it is often observed that the added functionalities do not necessarily improve potency even if they form strong hydrogen bonds. Here, we explore the thermodynamic and structural basis for those observations. KNI‐10033 is a potent experimental HIV‐1 protease inhibitor with picomolar affinity against the wild‐type enzyme (Kd = 13 pm). The potency of the inhibitor is the result of favorable enthalpic (ΔH = −8.2 kcal/mol) and entropic (−TΔS = −6.7 kcal/mol) interactions. The replacement of the thioether group in KNI‐10033 by a sulfonyl group (KNI‐10075) results in a strong hydrogen bond with the amide of Asp 30B of the HIV‐1 protease. This additional hydrogen bond improves the binding enthalpy by 3.9 kcal/mol; however, the enthalpy gain is completely compensated by an entropy loss, resulting in no affinity change. Crystallographic and thermodynamic analysis of the inhibitor/protease complexes indicates that the entropy losses are due to a combination of conformational and solvation effects. These results provide a set of practical guidelines aimed at overcoming enthalpy/entropy compensation and improve binding potency.
The Supply of Dentists and Access to Care in Rural Kansas
Authors: Allison R. Andrew , Manski Richard J.
Published: June 2007

ABSTRACT: 
Context: Rural deficits in dental care and oral health are well documented and are typically attributed to the low number of dentists practicing in rural areas, but the relationships between rural residence, dental supply, and access to care have not been firmly established, impeding the development of effective public policy. Purpose: The purpose of this study is to develop a conceptual framework for observed variations in dental supply, oral health, and access to dental care in rural versus nonrural areas, and to test key empirical implications of this framework (eg, whether lower levels of utilization are associated with the lack of dentists and/or other aspects of residence in a rural area). Methods: This study employs descriptive statistics, bivariate analyses, and multiple logistic regression to describe the relationship between oral health, access to care, and the supply of dentists in rural versus nonrural populations. Data analyzed includes Kansas' dental licensure records and the 2002 Behavioral Risk Factor Surveillance System. Findings: Bivariate results confirm that dental supply, access to care, and oral health are lower for populations living in rural areas. Multivariate models indicate that dentist supply has a positive and independent association with utilization, but that rurality is not associated with utilization and oral health after controlling for demographics and dentist supply. Conclusions: Findings are consistent with a conceptual framework linking the geography of rural residence, individual preferences for services such as dental care, and the financial disincentives for dentists to locate in rural areas.
Predictors of Colorectal Screening in Rural Colorado: Testing to Prevent Colon Cancer in the High Plains Research Network
Authors: Young Walter F. , McGloin Joe , Zittleman Linda , West David R. , Westfall John M.
Published: June 2007

ABSTRACT: 
Context:

Colorectal cancer is the second leading cause of cancer death in the United States, yet screening rates are well below target levels. Rural communities may face common and unique barriers to health care, particularly preventive health care.

Purpose:

To establish baseline attitudinal, knowledge, belief, and behavior measures on colorectal cancer screening and to identify barriers to or predictors of colorectal cancer screening.

Methods:

As part of a controlled trial using a quasi‐experimental, pretest, post‐test design, we conducted a baseline telephone survey of 1,050 rural eastern Colorado residents aged 50 years and older. Smaller counties were over‐sampled to ensure a minimum of 30 completed interviews per county.

Findings:

Seventy‐seven percent reported they ever had a colorectal cancer screening test and 59% were up‐to‐date on at least 1 test. The most important independent predictors of being up‐to‐date were having visited a doctor or other health care practitioner for a checkup in the past year, having personal or family history of colon polyps or cancer, and having asked for a colorectal cancer screening test. Financial concerns were reported reasons for not obtaining fecal occult blood testing by 18% and colonoscopy by 21%.

Conclusions:

This study suggests that health care providers should be vigilant in counseling their patients 50 and older to have a colorectal cancer test. Community programs designed to promote colon cancer screening should encourage residents to have regular contact with their primary care physician and ask their doctor for a screening test. Additionally, programs should provide financial assistance for testing for low‐income and uninsured patients.
The Association of Health and Functional Status with Private and Public Religious Practice among Rural, Ethnically Diverse, Older Adults with Diabetes
Authors: Arcury Thomas A. , Stafford Jeanette M. , Bell Ronny A. , Golden Shannon L. , Snively Beverly M. , Quandt Sara A.
Published: June 2007

ABSTRACT: 
Purpose:

This analysis describes the association of health and functional status with private and public religious practice among ethnically diverse (African American, Native American, white) rural older adults with diabetes.

Methods:

Data were collected using a population‐based, cross‐sectional, stratified, random sample survey of 701 community‐dwelling elders with diabetes in two rural North Carolina counties. Outcome measures were private religious practice, church attendance, religious support provided, and religious support received. Correlates included religiosity, health and functional status, and personal characteristics. Statistical significance was assessed using multiple linear regression and logistic regression models.

Findings:

These rural elders had high levels of religious belief, and private and public religious practice. Religiosity was associated with private and public religious practice. Health and functional status were not associated with private religious practice, but they were associated with public religious practice, such that those with limited functional status participated less in public religious practice. Ethnicity was associated with private religious practice: African Americans had higher levels of private religious practice than Native Americans or whites, while Native Americans had higher levels than whites.

Conclusions:

Variation in private religious practice among rural older adults is related to personal characteristics and religiosity, while public religious practice is related to physical health, functional status, and religiosity. Declining health may affect the social integration of rural older adults by limiting their ability to participate in a dominant social institution.
Medicare‐Certified Home Health Care: Urban‐Rural Differences in Utilization
Authors: Hartman Lacey , Jarosek Stephanie L. , Virnig Beth A. , Durham Sara
Published: June 2007

ABSTRACT: 
Context:

Availability of Medicare‐certified home health care (HHC) to rural elders can prevent more expensive institutional care. To date, utilization of HHC by rural elders has not been studied in detail.

Purpose:

To examine urban‐rural differences in Medicare HHC utilization.

Methods:

The 2002 100% Medicare HHC claims and denominator files were used to estimate use of HHC and to make urban‐rural comparisons on the basis of utilization levels within ZIP codes.

Findings:

Overall, the proportion of Medicare beneficiaries living in areas with little HHC utilization is relatively low. Rural elders, however, are more likely than their urban counterparts to live in such areas. Less than 1% of urban beneficiaries live in ZIP codes with no or low use of HHC, but over 17% of the most rural beneficiaries live in such areas.

Conclusions:

Continued monitoring of rural HHC utilization and access is important, especially as Medicare seeks to evaluate the effectiveness of payment increases to rural home health agencies.
Estimating Uncompensated Care Charges at Rural Hospital Emergency Departments
Authors: Bennett Kevin J. , Moore Charity G. , Probst Janice C.
Published: June 2007

ABSTRACT: 
Context: Rural hospitals face multiple financial burdens. Due to federal law, emergency departments (ED) provide a gateway for uninsured and self‐pay patients to gain access to treatment. It is unknown how much uncompensated care in rural hospitals is due to ED visits.

Purpose: To develop a national estimate of uncompensated care from patients utilizing the ED in rural hospitals.

Methods: Clinical data from the National Hospital Ambulatory Medical Care Survey‐ED (NHAMCS‐ED) from 1999 and 2000 were linked to billing data from South Carolina. National estimates of utilization and charges were calculated, with rurality and self‐pay status being the variables of focus.

Findings: Applying South Carolina billing data to national clinical data yields a national estimate for 1999‐2000 of nearly $441 billion in charges being generated through emergency departments, with self‐pay patients representing 9.0% of total charges. Rural self‐pay patients accounted for an estimated $3.5 billion in charges in 1999 and $5.3 billion in 2000. These charges may represent a total financial burden of more than $4 billion to rural hospitals.

Conclusions: Efforts should be made to reduce the uncompensated care burden on rural hospitals to ensure their viability. These efforts may include Medicaid/SCHIP expansions, FQHCs or RHCs, Critical Access Hospital Designation, or other indigent care programs that would reduce the need for self‐pay patients to utilize EDs.
Determination of Bromine and Iodine in Twenty‐three Geochemical Reference Materials by ICP‐MS
Authors: Chai Jian Y. , Muramatsu Yasuyuki
Published: June 2007

Trace amounts (from nanogram to microgram levels) of bromine and iodine were determined by inductively coupled plasma‐mass spectrometry (ICP‐MS) in twenty‐three geochemical reference materials issued by the GSJ, USGS, IAEA etc. The pyrohydrolysis technique was used to separate bromine and iodine from samples analysed in the form of powder. The accuracy and precision of the experimental values were assessed by the comparative analysis of well established reference materials such as USGS AGV‐1, BCR‐1 and IGGE GBW07312. The measured values agreed well with reported values within a 10% error range. We also report reliable new data for these elements in these geochemical reference materials.
The Use of EST as Adjunctive Therapy to Family‐Focussed Treatment
Authors: Paul Norman L. , Paul Betty Byfield
Published: June 2007

This article describes part of the process of using different experiential and therapeutic settings for patients. How we have used the EST training to compliment a family‐focussed treatment program and destigmatize a patient is reviewed.
PRELIMINARY HYDROLOGIC DESIGN OF SMALL FLOOD DETENTION RESERVOIRS1
Authors: Wycoff Ronald L. , Singh Udai P.
Published: June 2007

ABSTRACT. Flood detention reservoir design is a common problem encountered by engineers and others involved with water resources problems. This paper presents a method by which the volume of flood storage required for a single reservoir or a series of reservoirs may be estimated without using numeric flood‐routing techniques. The proposed procedure requires a minimum of computations and is most applicable to preliminary design situations where a high degree of accuracy is not required.
ECOLOGICAL CONSEQUENCE ASSESSMENT: EFFECTS OF BIOENGINEERED ORGANISMS1
Authors: Cairns John , Pratt James R.
Published: June 2007

ABSTRACT: The introduction of genetically altered microorganisms into natural ecosystems presents fundamentally new problems in risk assessment and ecological effect evaluation. Novel microorganisms, produced by any of several new methods, have the ability to survive and reproduce in the environment. Since most of these organisms are bacteria, they have the potential to interfere with natural processes, displace natural populations, infect new hosts, move between ecosystems, and cause far‐reaching ecological disturbanes. This paper reviews currently available methods in ecological research that might be used in evaluating the ecological effects of releasing genetically altered microorganisms. Both structural and functional evaluations are critically reviewed. Microcosm, mesocosm, and field tests should provide valuable predictions concerning the potential ecological impact of genetically altered organisms. Ecosystem assessments will also be useful in post‐release studies such as those currently used to evaluate toxic impacts. The present problem does not require the development of new testing methods but rather the creation of adequate predictive models (both conceptual and systems‐based) to predict the potential for adverse effect of genetically altered organisms.
OPTICAL CHARACTERISTICS OF NEW ZEALAND RIVERS IN RELATION TO FLOW1
Authors: Smith David G. , Davies‐Colley Robert J. , Knoef Jeroen , Slot Gerritdina W. J.
Published: June 2007

ABSTRACT: Six years (1989–1994) of data from New Zealand's National Rivers Water Quality Network were used to characterize the optical water quality regime of river waters as regards: visual clarity (black disc visibility), turbidity, and light‐absorbing aquatic humic material (referred to as ‘yellow substance,’ measured as light absorption at 440 nm). Quantitative relationships between optical water quality variables and flow in rivers are well‐described by power law expressions. Visual clarity usually decreases strongly with increasing flow in individual rivers. There is a strong, inverse relationship between turbidity and visibility, but, because of differences between sites, turbidity is not a good general predictor of visual clarity (the attribute of real interest) in rivers. Yellow substance tends to increase with increasing flow, probably because during rainstorms, soil water high in yellow‐colored humic material, rather than rain water or ground water, dominates discharge. Therefore, rivers are typically clear and low in humic matter at low flow, and turbid and yellow‐colored at high flow.
A two-component simulation model to teach respiratory mechanics
Authors: Kuebler Wolfgang M. , Mertens Michael , Pries Axel R.
Published: June 2007

Interactive learning has been proven instrumental for the understanding of complex systems where the interaction of interdependent components is hard to envision. Due to the mechanical properties and mutual coupling of the lung and thorax, respiratory mechanics represent such a complex system, yet their understanding is essential for the diagnosis, prognosis, and treatment of various respiratory disorders. Here, we present a new mechanical model that allows for the simulation of respiratory pressure and volume changes in different ventilation modes. A bellow reflecting the “lung” is positioned within the inverted glass cylinder of a bell spirometer, which is sealed by a water lock and reflects the “thorax.” A counterweight attached to springs representing the elastic properties of the chest wall lifts the glass cylinder, thus creating negative “pleural” pressure inside the cylinder and inflating the bellow. Lung volume changes as well as pleural and intrapulmonary pressures are monitored during simulations of spontaneous ventilation, forced expiration, and mechanical ventilation, allowing for construction of respiratory pressure-volume curves. The mechanical model allows for simulation of respiratory pressure changes during different ventilation modes. Individual relaxation curves constructed for the lung and thorax reflect the basic physiological characteristics of the respiratory system. In self-assessment, 232 medical students passing the physiology laboratory course rated that interactive teaching at the simulation model increased their understanding of respiratory mechanics by 70% despite extensive prior didactic teaching. Hence, the newly developed simulation model fosters students' comprehension of complex mechanical interactions and may advance the understanding of respiratory physiology.
Configuration of the hemoglobin oxygen dissociation curve demystified: a basic mathematical proof for medical and biological sciences undergraduates
Authors: Leow Melvin Khee-Shing
Published: June 2007

The oxygen dissociation curve (ODC) of hemoglobin (Hb) has been widely studied and mathematically described for nearly a century. Numerous mathematical models have been designed to predict with ever-increasing accuracy the behavior of oxygen transport by Hb in differing conditions of pH, carbon dioxide, temperature, Hb levels, and 2,3-diphosphoglycerate concentrations that enable their applications in various clinical situations. The modeling techniques employed in many existing models are notably borrowed from advanced and highly sophisticated mathematics that are likely to surpass the comprehensibility of many medical and bioscience students due to the high level of “mathematical maturity” required. It is, however, a worthy teaching point in physiology lectures to illustrate in simple mathematics the fundamental reason for the crucial sigmoidal configuration of the ODC such that the medical and bioscience undergraduates can readily appreciate it, which is the objective of this basic dissertation.
Combination of didactic lectures and case-oriented problem-solving tutorials toward better learning: perceptions of students from a conventional medical curriculum
Authors: Ghosh Sarmishtha
Published: June 2007

The Department of Physiology of Pramukhswami Medical College at Anand, Gujarat, India, started using problem-based learning in a modified way along with didactic lectures to improve students’ understanding and motivate them toward self-directed study. After the didactic lectures were taken for a particular system, clearly defined short clinical problems related to that system were given to the students in the tutorial classes. Each tutor was assigned three to four groups of five to six students each. Problems were accompanied with relevant questions so as to streamline the thought processes of the first-year undergraduates. The tutor then facilitated the study process, and the students discussed among themselves to derive their solutions. At the end of the sessions, feedback was taken from the students through a planned questionnaire on a three-point scale. Of a total of 278 students over a span of 3 yr from 1999 to 2002, 74.4% of students favored a judicious mixture of didactic lectures and case-oriented problem solving in tutorial classes to be an efficient modality in understanding a system under study, and 84% of students stated the mixture of didactic lectures and case-oriented problem solving to be beneficial in relating a clinical condition to the basic mechanism; 82% of students believed that this module helped with better interactions among their batch mates, and 77.2% of students hoped to perform better in the university examination due to this new teaching/learning modality. They also expressed that this gave them ample motivation to do self-directed learning. It may therefore be concluded from the results of the present study that it is possible to have a problem-based learning module in the form of case-oriented problem-solving tutorials coexistent with the traditional didactic lecture module in the first year of medical education under a conventional curriculum.
Creative teaching assistant organization to maintain an Integrative Physiology course with 440 students
Authors: Murrant Coral L.
Published: June 2007

We were recently challenged with trying to maintain the integrity and learning experience of our Physiology course, which included the use of long-answer, essay-style test questions, with a class size that increased over 2 yr by ∼200 students. We reorganized the teaching assistant (TA) support structure in an attempt to keep the testing style and mark (or grade) the exams accurately, in a timely fashion, and provide feedback to the students that want it. Each of four TAs became experts in two sections of the course. To assess our success, TA time allocation for specific duties was recorded. Marking (or grading) accuracy was assessed by recording test data including the number of tests returned for remarking and how much marks changed by when a grade was reassessed. Student feedback was solicited to determine whether this structure provided adequate feedback and support to the students. TAs spent an average of 115 h and 35 min ± 7 h 21 min of a total of 140 h contracted. On average, 13.2 ± 0.5% of the tests were identified as being inaccurately graded by 4.2 ± 0.7%. When asked to score whether the statement of assessment of students was fair, it scored 4.5 out of 5, where 5 equals strongly agree. When asked whether the course provided a worthwhile learning experience, the question scored 4.84 out of 5. Thus, we were successful at marking the exams accurately, in a timely fashion, and providing the necessary feedback, and we were successful at maintaining the objectives of the Physiology course with a class size of 440 students.
Texts in context: Horace Davenport, carbonic anhydrase, and gastric acid secretion
Authors: Rangachari P. K.
Published: June 2007

Many standard textbooks of physiology have a diagram that shows the transporting elements that lead to the secretion of HCl by the parietal cell. The transporters are neatly aligned, and students see an elegant mechanism that neatly balances the ions to maintain electroneutrality. They little realize the time and effort required to tease out each of those steps bit by bit. This essay uses three papers by Horace Davenport to highlight the experimental evidence for a crucial step in that process: the generation of H+ and HCO3− through the agency of carbonic anhydrase. All three papers form part of the classic papers available through the American Physiological Society Legacy Project.
Low-cost computer-controlled current stimulator for the student laboratory
Authors: Güçlü Burak
Published: June 2007

Electrical stimulation of nerve and muscle tissues is frequently used for teaching core concepts in physiology. It is usually expensive to provide every student group in the laboratory with an individual stimulator. This article presents the design and application of a low-cost [about $100 (U.S.)] isolated stimulator that can be controlled by two analog-output channels (e.g., output channels of a data-acquisition card or onboard audio channels) of a computer. The device is based on a voltage-to-current converter circuit and can produce accurate monopolar and bipolar current pulses, pulse trains, arbitrary current waveforms, and a trigger output. The compliance of the current source is ±15 V, and the maximum available current is ±1.5 mA. The device was electrically tested by using the audio output of a personal computer. In this condition, the device had a dynamic range of 46 dB and the available pulse-width range was 0.1–10 ms. The device is easily programmable, and a freeware MATLAB script is posted on the World Wide Web. The practical use of the device was demonstrated by electrically stimulating the sciatic nerve of a frog and recording compound action potentials. The newly designed current stimulator is a flexible and effective tool for teaching in the physiology laboratory, and it can increase the efficiency of learning by maximizing performance-to-cost ratio.
Teaching basic gastrointestinal physiology using classic papers by Dr. Walter B. Cannon
Authors: Bertrand Paul P. , Bertrand Rebecca L.
Published: June 2007

The movements of the gastrointestinal tract, as described by Walter B. Cannon 100 years ago, reveal much about the functions of this unique organ and how it is controlled by the body. Two classic papers by Cannon provide a rare glimpse into the hidden functions of the body and give students a great example of the scientific method in action. In this essay, we describe the basic movements and functions of the gastrointestinal tract as revealed by X-rays, contrast meals, and Cannon's careful observations. It is Cannon's experimental care and obvious interest in his subject matter that can provide your students with a taste of the excitement of discovery and insight into the processes by which experimental science moves forward.
Quantitative Circulatory Physiology: an integrative mathematical model of human physiology for medical education
Authors: Abram Sean R. , Hodnett Benjamin L. , Summers Richard L. , Coleman Thomas G. , Hester Robert L.
Published: June 2007

We have developed Quantitative Circulatory Physiology (QCP), a mathematical model of integrative human physiology containing over 4,000 variables of biological interactions. This model provides a teaching environment that mimics clinical problems encountered in the practice of medicine. The model structure is based on documented physiological responses within peer-reviewed literature and serves as a dynamic compendium of physiological knowledge. The model is solved using a desktop, Windows-based program, allowing students to calculate time-dependent solutions and interactively alter over 750 parameters that modify physiological function. The model can be used to understand proposed mechanisms of physiological function and the interactions among physiological variables that may not be otherwise intuitively evident. In addition to open-ended or unstructured simulations, we have developed 30 physiological simulations, including heart failure, anemia, diabetes, and hemorrhage. Additional stimulations include 29 patients in which students are challenged to diagnose the pathophysiology based on their understanding of integrative physiology. In summary, QCP allows students to examine, integrate, and understand a host of physiological factors without causing harm to patients. This model is available as a free download for Windows computers at http://physiology.umc.edu/themodelingworkshop .
The Structure of Incomplete Destructive Breakdown Spots in Thin Polymer Films
Authors: Sapieha S. , Jablonski W. , Kryszewski M.
Published: June 2007

Experimental observations are given on the structure of breakdown spots in thin layers of polystyrene and
polybenzene obtained by a glow discharge technique. The levels of energy associated with different types of
breakdown are identified and it is shown that within the range of breakdown energy level, lower than 10‐5 joules,
non‐destructive breakdown takes place. At higher energies, partial destruction of the breakdown channel occurs and
with energy levels greater than 5 × 10‐3 joules, single hole, self‐healing breakdown with complete destruction of the
inner morphological channel structure occurs.The nature of the breakdown is discussed in electrical and electronmicroscopy terms.
Destructive D.C. Breakdown in “Built‐Up” Barium Stearate Films
Authors: Agarwal V. K. , Srivastava V. K.
Published: June 2007

The thickness dependence of maximum breakdown voltage (d.c.) leading to the destruction of the film has been
reported for “built‐up” barium stearate films in the thickness range (400 Å–1000 Å). These films were chosen
because of their promising applications for making dielectric devices, and because their thickness is accurately
known and controllable (within 25 Å). The breakdown voltage is found to be almost independent of thickness and
microscopic observations in transmission did not show the occurrence of “single‐hole” and “propagating” breakdowns,
as observed by Klein et al. in evaporated film systems. The I–V characteristics in the “non‐destructive” phase have
also been studied and the observed maximum breakdown voltage has been distinguished from the “maximum voltage
breakdown” observed by Klein et al.
A Simulative Approach to Electron Conduction in Thick‐Film Resistors
Authors: Jacoboni C. , Prudenziati M. , Rizzi A.
Published: June 2007

A simulative approach to the calculation of electrical transport in thick‐film resistors is presented, in which electrons are considered to hop from and to metallic grains and localized states in the glass. For concentrations of metallic grains sufficiently low and of localized states sufficiently high, a maximum in conductivity as a function of temperature is obtained due to a balance between the tendency of temperature to favour hopping and to oppose an ordered response to an external force.
Mounting of Micropackages in Vapour Phase Soldering and Study of Ageing Mechanism
Authors: Val Christian M. , Agniel Jacques D.
Published: June 2007

In this paper, the metallurgical aspect of conductor/solder/metallisation are analysed after cycling and ageing and the mechanism of degradation of the micro‐solder is considered. As a consequence a new solder process of reflow is analysed (vapor phase reflow).
Experience With Polymer Thick Film Technology
Authors: Hulkkonen Raimo , Jarvinen Eero , Sortti Vesa
Published: June 2007

The paper describes a user′s experiences with polymer thick film resistor technology. The characteristics studied are resistance values and their distributing. Parameters affecting these characteristics are the material of the substrate, and the curing of the polymer resistor paste. The test conditions (temperature cycling, dip soldering, high temperature storaging) were chosen to simulate the environmental conditions, through which the polymer resistor circuits have to go during the assembly process of a typical consumer electronics product. The polymer pastes studied were from commercial paste manufacturers in USA, Europe and Japan.

Additional background information, to help in understanding the behaviour of different polymer resistor materials, was obtained through the differential thermo analysis (DTA) of the pastes under investigation.
Digital Carbon Monoxide Detector /11/
Authors: Dauchot J. P. , Hecq A. , Grognia M. T.
Published: June 2007

The switch off concentration phenomena in carbon monoxide oxidation on platinum and the parallel steep variation of resistance or surface potential of thin platinum films are used to develop a carbon detector. Coating the platinum film with an increasing thickness of polytetrafluorethylene (PTFE) makes this switch off point move to increasing CO concentrations. Therefore a series of electrical elements, platinum thin film resistances, platinum M.O.S. diodes or platinum gate M.O.S. transistors covered by calibrated thicknesses of PTFE will switch off at well determined CO concentrations and can continue the basis of a digital detector.
Thin Film Transistors and Thin Film Transistor Circuits
Authors: Van Calster Andre
Published: June 2007

In this paper the possible circuit applications of thin film transistors, made by shadow masks, are discussed. Special attention is paid to the basic parameters determining the circuit properties.
Silicon and Hybrid Micro‐Electronic Sensors
Authors: Middelhoek S. , Noorlag D. J. W. , Steenvoorden G. K.
Published: June 2007

The penetration of micro‐electronics into new markets is seriously hampered by the lack of efficient, low‐cost sensors. It is not surprising therefore to find that these devices are the subject of research in many laboratories. This paper gives a review of the most important sensors which are fabricated in silicon planar or hybrid technology. The review is preceded by some general considerations with respect to measurement systems and signal conversion.
Hybrids for Automotive Applications
Authors: Bergfried Dietrich
Published: June 2007

The design aspects of automotive hybrids are discussed in general and illustrated by two specific examples, a thick film module used in the electronic fuel injection controller and a solid state ignition module. The environmental test conditions for the automotive environment are summarized, and it is shown how these conditions influence the hybrid design.
Guidelines for Finer Lines in Thick Film Circuitry
Authors: Bertrams P. J. B. , Keuper W. , Koch G. , Van Mourik J. H. C.
Published: June 2007

Screen quality, ink, behaviour, printersettings, substrate surface condition and dry and sinterconditions determine print results. For high density printing the quality of each of those parameters is important. It was found, that ink and screen play the most important part.

The metal gauze screen provided with the mask must have a flat surface (roughness < 5/μm) and an even thickness and gauze tension. For a number of inks the viscosity at low shear‐rates defines the fine line capabilities. Some tolerance on printersettings is found to be acceptable. The application of a surfactantson the substrate surface proves to be a solution to gain a better line definition. During levelling the evaporation of solvents at room temperature has to be favoured for an optimum result.
The Influence of Contaminants During the Firing of Inks
Authors: Van Gorp A. J. M. , Van Mourik J. H. C.
Published: June 2007

During firing of resistor materials the resistance is influenced by gaseous contaminants and by compounds given off by other pastes. Nearly all inorganic salts which are slightly volatile at the firing temperature, and some rather stable organic materials influence the resistor properties. Halogenated materials are the most important and the higher ohmic series the most sensitive.

For aluminium conductors a very high sensitivity to fluorinated and chlorinated compounds has been found but in this case organic compounds have no influence.
Thick Film Fail‐Safe Resistors
Authors: Nowak St. , Wojcicka D. L.
Published: June 2007

The investigations of low resistance thick film fail‐safe resistors are presented. Particularly the shape of a resistive path; the temperature of the central part of the resistor while increasing the power up to 4 Watts; the kind of composition material for the resistive path vs. extensometer effect, and the stability of the resistor are discussed.
Parameters That Influence the Ultrasonic Bond Quality
Authors: Derks P. L. L. M.
Published: June 2007

This paper summarizes some non‐destructive ultrasonic bond quality test methods. Systems described in the literature are mainly based on monitoring the deviation of the vibration amplitude during welding and the correlation between the bond strength with these deviations. Practical application of these principles can give discouraging results. A better understanding of the bond formation process should enable one to understand what causes the amplitude to deviate, and why this is strongly dependent on the ultrasonic bond system involved.
The Influence of Conductor Particle Size Distribution on the Blending Curve of Epoxy‐Based Thick Film Resistors
Authors: Ulug Bulent , Robertson John M. , Ewen Peter J. S.
Published: June 2007

The influence of conductor particle size distribution on the blending curve of epoxy‐based thick film resistors has been investigated. It was found that the critical volume fraction shifts to higher values as the spread of the conductor particle size distribution decreases. The results are interpreted in terms of a model whose main parameter is the contact probability for the conductor particles.