bluuebunny/crossref_metadata_2025 huggingface dataset:
Behaviour of tip-leakage flow in an axial flow compressor rotor
Authors: Wu Y , Chu W
Published: February 2007

The current paper reports on investigations with an aim to advance the understanding of the flowfield near the casing of a small-scale high-speed axial flow compressor rotor. Steady three-dimensional viscous flow calculations are applied to obtain flowfields at various operating conditions. To demonstrate the validity of the computation, the numerical results are first compared with available measured data. Then, the numerically obtained flowfields are analysed to identify the behaviour of tip-leakage flow, and the mechanism of blockage generation arising from flow interactions between the tip clearance flow, the blade/casing wall boundary layers, and non-uniform main flow.

The current investigation indicates that the ‘breakdown’ of the tip-leakage vortex occurs inside the rotor passage at the near stall condition. The vortex ‘breakdown’ results in the low-energy fluid accumulating on the casing wall spreads out remarkably, which causes a sudden growth of the casing wall boundary layer having a large blockage effect. A low-velocity region develops along the tip clearance vortex at the near stall condition due to the vortex ‘breakdown’. As the mass flow rate is further decreased, this area builds up rapidly and moves upstream. This area prevents incoming flow from passing through the pressure side of the passage and forces the tip-leakage flow to spill into the adjacent blade passage from the pressure side at the leading edge. It is found that the tip-leakage flow exerts a little influence on the development of the blade suction surface boundary layer even at the near stall condition.
Self-starting capability of a Darrieus turbine
Authors: Dominy R , Lunt P , Bickerdyke A , Dominy J
Published: February 2007

Darrieus-type vertical axis wind turbines have a number of potential advantages for small-scale and domestic applications. For such applications, the issues of cost and reliability are paramount and hence simplicity of design of the structure, the generator, and any control system is vital. A particular concern relating to Darrieus turbines is their potential to self-start. If, as has been suggested by several authors, they require external assistance to start then much of their advantage is lost. The purpose of the study described here is, therefore, to investigate their starting performance through the development and validation of computational simulation and to determine the parameters that govern the capability to self-start. A case study is presented based upon the use of the widely used and well documented, symmetrical NACA 0012 turbine blade profile. It is shown that a lightly loaded, three-bladed rotor always has the potential to self start under steady wind conditions, whereas the starting of a two-bladed device is dependent upon its initial starting orientation.
An investigation on fretting wear behaviour of MoS2-bonded coating on AISI 4340 steel
Authors: Ramesh R , Gnanamoorthy R
Published: February 2007

Fretting wear characteristics of Molybdenum disulphide (MoS2)-bonded solid lubricant coating on structural steel, AISI 4340, when fretted against hardened-tempered bearing steel, AISI 52100 are reported in this paper. Fretting wear tests were conducted at different normal loads and at constant slip amplitude of 60 μm. Coefficient of friction under fretting conditions and wear resistance were measured. The MoS2-bonded solid lubricant offers improved fretting wear resistance against bearing steels. Substrate hardness has influenced the coating behaviour at high loads. The fretting wear resistance also depends upon the normal load and the nature of contact, stick slip, or gross slip.
Brain-Derived Neurotrophic Factor Regulates the Maturation of Layer 4 Fast-Spiking Cells after the Second Postnatal Week in the Developing Barrel Cortex
Authors: Itami Chiaki , Kimura Fumitaka , Nakamura Shun
Published: February 2007

Brain-derived neurotrophic factor (BDNF) has been reported to play a critical role in modulating plasticity in developing sensory cortices. In the visual cortex, maturation of neuronal circuits involving GABAergic neurons has been shown to trigger a critical period. To date, several classes of GABAergic neurons are known, each of which are thought to play distinct functions. Of these, parvalbumin (PV)-containing, fast-spiking (FS) cells are suggested to be involved in the initiation of the critical period. Here, we report that BDNF plays an essential role in the normal development of PV–FS cells during a plastic period in the barrel cortex. We found that characteristic electrophysiological properties of PV–FS cells, such as low spike adaptation ratio, reduced voltage sags in response to hyperpolarization, started to develop around the second postnatal week and attained adult level in several days. We also found that immunoreactivity against PV was also acquired after the similar developmental time course. Then, using BDNF(−/−) mice, we found that these electrophysiological as well as chemical properties were underdeveloped or did not appear at all. We conclude BDNF regulates the development of electrophysiological and immunohistochemical characteristics in PV–FS cells. Because BDNF is suggested to regulate the initiation of plasticity, our results strongly indicate that BDNF is involved in the regulation of the critical period by promoting the functional development of PV–FS GABAergic neurons.
Parvalbumin Is a Mobile Presynaptic Ca2+Buffer in the Calyx of Held that Accelerates the Decay of Ca2+and Short-Term Facilitation
Authors: Müller Martin , Felmy Felix , Schwaller Beat , Schneggenburger Ralf
Published: February 2007

Presynaptic Ca2+signaling plays a crucial role in short-term plasticity of synaptic transmission. Here, we studied the role of mobile endogenous presynaptic Ca2+buffer(s) in modulating paired-pulse facilitation at a large excitatory nerve terminal in the auditory brainstem, the calyx of Held. To do so, we assessed the effect of presynaptic whole-cell recording, which should lead to the diffusional loss of endogenous mobile Ca2+buffers, on paired-pulse facilitation and on intracellular Ca2+concentration ([Ca2+]i) transients evoked by action potentials. In unperturbed calyces briefly preloaded with the Ca2+indicator fura-6F, the [Ca2+]itransient decayed surprisingly fast (τfast, ∼30 ms). Presynaptic whole-cell recordings made without additional Ca2+buffers slowed the decay kinetics of [Ca2+]iand paired-pulse facilitation (twofold to threefold), but the amplitude of the [Ca2+]itransient was changed only marginally. The fast [Ca2+]idecay was restored by adding the slow Ca2+buffer EGTA (50–100 μm) or parvalbumin (100 μm), a Ca2+-binding protein with slow Ca2+-binding kinetics, to the presynaptic pipette solution. In contrast, the fast Ca2+buffer fura-2 strongly reduced the amplitude of the [Ca2+]itransient and slowed its decay, suggesting that the mobile endogenous buffer in calyces of Held has slow, rather than fast, binding kinetics. In parvalbumin knock-out mice, the decay of [Ca2+]iand facilitation was slowed approximately twofold compared with wild-type mice, similar to what is observed during whole-cell recordings in rat calyces of Held. Thus, in young calyces of Held, a mobile Ca2+buffer with slow binding kinetics, primarily represented by parvalbumin, accelerates the decay of spatially averaged [Ca2+]iand paired-pulse facilitation.
I'm Ready for My Close‐up Now: Electronic portfolios and How We Read Identity
Authors: Williams Bronwyn T.
Published: February 2007

Electronic portfolios allow students to include video, images, hyperlinks, and audio, along with written texts, to create varied and comprehensive representations of what they have accomplished. Such collections of information also change the ways that teachers and students choose to present themselves and the ways that we read these presentations of self. As we learn more about how we read and respond to identities created by combinations of word, image, and sound, we need to help students think more carefully and critically about how this should influence the way they create and compile electronic portfolios.
Understanding and Teaching English‐Language Learners
Authors: Opitz Michael F. , Harding‐DeKam Jenni L.
Published: February 2007

The authors review several professional resources designed to assist those working with students who are learning English.
Polymeric Resins Adsorb and Release Oryzalin in Response to pH
Authors: Fain Glenn B. , Grey Timothy L. , Wehtje Glenn R. , Gilliam Charles H. , Osborne Jason A.
Published: February 2007

Two polymeric anion-exchange resins and one sorbent resin were evaluated for their propensity to adsorb, and subsequently desorb, oryzalin. The intent was to determine whether these resins could adsorb and subsequently release oryzalin in a manner that would render these resins as an option for slow-release herbicide delivery. The dinitroaniline herbicide oryzalin is weakly acidic with a dissociation constant (pKa) of 8.6. An additional objective was to determine whether altering the pH between sorption and desorption would enhance the desired performance. Maximum oryzalin sorption by the two anion-exchange resins was between 127 and 132 mg g−1ai. The sorbent resin was adsorbed at a maximum concentration of 191 mg g−1ai. Maximum sorption occurred with the pH 10 solutions with all resins. Average oryzalin desorption by the anion-exchange resin was between 0.12 and 3.84 mg g−1per desorption event. Maximum desorption occurred at pH 6.0. Results reveal that the resins evaluated may have merit for slow-release herbicide delivery.
Field Margin Weed-Species Diversity in Relation to Landscape Attributes and Adjacent Land Use
Authors: Sosnoskie Lynn M. , Luschei Edward C. , Fanning Mark A.
Published: February 2007

The importance of managing weeds in seminatural habitats that are adjacent to farm fields is unclear. Weedy-margin vegetation may harbor pests or pathogens and may ALSo serve as source populations for ongoing immigration of weeds into the field. It is ALSo possible, however, that margin vegetation provides habitat for organisms that consume weed seeds or suppress the likelihood of pest or pathogen outbreak. We examined the nature of margin habitat using spatial-scaling of Weed-Species richness as an ecological assay. In 2003, we recorded the occurrence of weedy species along the perimeters of 63 fields in Wisconsin. The fields were distributed within six counties that differed in topography, geological history, local climate, and soil type and which spanned the range of variability in the agricultural landscape. We identified seven habitats that differed in geology and land use. The relationship between species richness and margin class was estimated using an analog of the power law. Additionally, we investigated broadscale correlates of habitat heterogeneity at the field level, using a modeling strategy that included additional explanatory factors logically connected to plant diversity. Using a model-confrontation approach, the survey supported the inclusion of two topographical diversity indices, elevation gradient and a field-shape index, into our model. Our broadscale survey provides information on one of a suite of important considerations needed to make decisions about the importance of managing weeds in field margins.
Managing Sonchus arvensis using mechanical and cultural methods
Authors: VANHALA P. , LÖTJÖNEN T. , HURME T.
Published: February 2007

Perennial sow-thistle (Sonchus arvensis L.) represents an increasing problem in Finland. Options for mechanical and cultural control of S. arvensis were studied in a field experiment on clay soil under organic production. The experiment consisted of different crop sequences: spring cereal (barley, Hordeum vulgare L., in 2001, oats, Avena sativa L., in 2002) with or without inter-row hoeing and/or stubble cultivation, bare fallow, fibre hemp (Cannabis sativa L.), and ley with mowing. In 2003 the entire field was sown to spring wheat. Crop plant and Sonchus shoot density and dry mass prior to cereal harvest and crop yield were assessed. The control effect was rated: bare fallow > ley > cereal with or without inter-row hoeing > poor growth fibre hemp. Bare fallow was an effective but costly way to reduce S. arvensis infestation. Introduction of a regularly mown green fallow or silage ley in the crop rotation is advisable. Mechanical weed control by inter-row hoeing in cereals limits S. arvensis growth. Infestation might also be reduced by stubble cultivation in autumn. When managing S. arvensis using mechanical and cultural methods, appropriate options, including a competitive crop, should be chosen for the specific field and rotation.;
Depleted Uranium: All the Questions about Du and Gulf War Syndrome are Not Yet Answered
Authors: Bertell Rosalie
Published: February 2007

For 15 years, the debate about depleted uranium (DU) and its detrimental effects on the health of veterans of the Gulf War of 1991, on the Iraqi people and military (and subsequently on the people of Kosovo, Afghanistan, and Iraq during the second war) has remained unresolved. Meanwhile, the number of Gulf War veterans who have developed the so-called Gulf War syndrome has risen to about one-third of the 800,000 U.S. forces deployed, and unknown proportions of those involved in the subsequent wars. Uncounted civilians and personnel of other nations that fought in Iraq and other wars since 1991 have also been afflicted. The veterans have suffered from multiple serious physiological disorders and have received little or no official recognition, medical relief, or compensation. We need to take another look at this issue, using a holistic and interactive model for the toxic matrix of exposures, identifying the major roadblocks to resolving the scientific questions, and finding appropriate medical and political responses. This commentary is such an attempt.
Factors Influencing Ergonomic Intervention in Construction: Trunkman Case Study
Authors: Fulmer Scott , Azaroff Lenore S. , Moir Susan
Published: February 2007

This case study examines factors affecting the use of equipment designed to prevent lower back strain in laborers who pour concrete on major highway construction sites. Qualitative methods of organizational analysis were used to characterize factors identified from interviews and participant observation. The major obstacles to the use of the control on site were

Managers placing a low priority on ergonomics Safety officers' limited power in organizational hierarchies Rationalizing, rather than challenging, resistance to change Lack of a forum to share knowledge about interventions

Several organizational factors impeded the adoption of a technically effective, low-cost safety control on the site studied. The implementation of the control ultimately resulted from actions taken by the investigators, suggesting that safety programs present at the site are not always adequate to realize feasible interventions.
Online Study Groups: Reciprocal Peer Questioning versus Mnemonic Devices
Authors: Johnson Genevieve Marie
Published: February 2007

One hundred sixty students in an educational psychology course used WebCT Discussions to satisfy one of two study group conditions, reciprocal peer questioning or mnemonic devices. Students made postings according to their assigned study strategy in order to facilitate the learning of their group. At the end of the academic term, student permission was obtained to use three types of data for purposes of the investigation: 1) course grades; 2) WebCT records; and 3) rating scale responses that assessed personal evaluation of the virtual study groups. There were no differences between the two study conditions in terms of academic achievement. However, students in the reciprocal peer questioning condition made more postings and read more articles than students in the mnemonics group. Correspondingly, students in the reciprocal peer questioning group reported higher levels of satisfaction with the virtual study experience.
Child Poverty in Rich Countries, 2005, Part II
Authors: McMahon Jean
Published: February 2007

Protecting children from the sharpest edges of poverty during their years of growth and formation is both the mark of a civilized society and a means of addressing some of the evident problems that affect the quality of life in the economically developed nations. The proportion of children living in poverty has risen in a majority of the world's developed economies over the past decade. This report asks what is driving poverty rates upwards and why some OECD countries are doing a much better job than others in protecting children at risk.
Chickens and Eggs: Examining the Links between Mental Health and Chronic Disease
Authors: Dowrick Christopher
Published: February 2007

Interactions between physical and mental illness are complex. Each may lead to the other; both arise from common antecedents; they may be synergistic or associations may be spurious. There is an expanding evidence base for the efficacy of interventions at the psychological level. Patients' views on their healthcare remain crucial.
Anxiety Symptoms in Patients with Hypertension: A Community-Based Study
Authors: Wei Tie-Min , Wang Lexin
Published: February 2007

Objectives:

To investigate incidence and severity of anxiety symptoms in patients with hypertension.

Methods:

A cross-sectional survey in 891 (432 females) hypertensive patients was conducted in a regional community. All patients were interviewed and detailed physical examination was performed. Zung self-rating anxiety scale (SAS) was used to evaluate the severity of anxiety symptoms.

Results:

Anxiety was diagnosed on clinical grounds in 103 patients (11.6%) who also had a raw SAS score of more than 40. In all subjects surveyed, the average SAS score in females was higher than males (32.9 ± 7.1 vs 31.2 ± 6.4, p < 0.001). The average SAS score was also higher in patients with hypertension of more than 3 years (32.4 ± 7.0 vs 31.2 ± 6.1, p = 0.01), in patients with severe hypertension (39.8 ± 6.9 vs 29.6 ± 4.5, p < 0.001), and in patients with a history of hospitalization for cardiovascular disorders (35.7 ±7.7 vs 31.7 ±6.6, p < 0.001). Multivariate regression analysis showed that female gender, duration of hypertension, and hospitalization history were independent predictors of anxiety symptoms ( p < 0.05).

Conclusions:

Almost 12% of hypertensive patients have anxiety symptoms. Female gender, the duration of hypertension, and the history of hospitalization are associated with the occurrence and severity of anxiety symptoms in patients with hypertension.
The Boundary Questionnaire: Its Preliminary Reliability and Validity
Authors: Harrison Robert H. , Hartmann Ernest , Bevis Judith
Published: February 2007

The Boundary Questionnaire was developed to measure boundaries between various aspects of psychological experience: between primary process and secondary process thinking; between internal and external experiences; and between loose vs. organized ways of arranging ideas and opinions. A reliable 138-item scale was developed. All 138 items loaded positively on the first principal component, supporting the generality of the boundary concept. The items were then analyzed into 12 factors, each of which measured a different aspect of boundary thin-ness. Factor scores differentiated between theoretically thin groups (nightmare sufferers and art students), and a theoretically thick group of Naval officers. Many of the factor scores correlated with frequency of dream recall, and with various MMPI scales. The questionnaire promises to be useful in the study of a wide variety of boundary phenomena.
Distortion of Some of the Basic Principles of Public Health Practice in India
Authors: Banerji Debabar
Published: February 2007

India's political leadership has chosen personnel from the Indian Administrative Service cadre of generalist administrators and from the clinician-dominated cadre of the Central Health Services to run the country's health service system. The personnel's inadequate or distorted understanding of some of the basic principles of public health practice—such as developing an epidemiological approach to solving community health problems, choice of appropriate technology, and optimization of health service systems—has had a very deleterious effect on the health service system. These administrators have become vulnerable to manipulation by personnel from international agencies, who also have questionable public health credentials, to create space for imposition of their technocentric, ill-conceived, and ill-designed agenda. To rationalize adoption of such an obviously faulty agenda, they have to be ahistorical, apolitical, and atheoretical and indulge in misinformation, disinformation, and suppression and manipulation of information. This amounts to what Navarro has termed “intellectual fascism.”
Swahili Translation and Validation of the Patient Health Questionnaire-9 Depression Scale in the Kenyan Head and Neck Cancer Patient Population
Authors: Omoro S.A.O. , Fann J. R. , Weymuller E. A. , MacHaria I. M. , Yueh B.
Published: February 2007

Background:

Depression is an important predictor of post therapy quality of life (QOL) in head and neck (H&N) cancer patients. In addition, depression rates may vary among cultures.

Objective:

As part of a larger cross cultural study on post therapy QOL differences in H&N cancer patients, the goal of this project was to translate a well-validated English language depression scale into Swahili, and then validate this scale in Kenyan H&N cancer patients.

Methods, Settings and Subjects:

In Part 1 of the study, we translated the Patient Health Questionnaire-9 (PHQ-9) into Swahili, adhering to established International Quality of Life Association (IQOLA) guidelines. In Part 2, we psychometrically validated the newly translated scale using a prospective study of 48 patients at the Kenyatta National Hospital ENT clinic in Nairobi, Kenya.

Results:

The Swahili PHQ-9 had good test retest reliability (Intraclass correlation coefficient, 0.71) and internal consistency (Cronbach's alpha=0.80). It also had good construct validity, as scores correlated strongly with TNM stage (Chi square=123, p < 0.05), and with the composite and global scores of an H&N cancer specific QOL scale (UW-QOL, r = −0.87, p < 0.05).

Conclusion:

The Swahili version of the PHQ-9 is a reliable scale in Kenyan H&N cancer patients, and is a valuable tool in screening for and monitoring of depression as a function of QOL in this population.
A Successful University-Foundation Partnership to Assist Non-Traditional Transfer Women
Authors: Austin Sandra A.
Published: February 2007

This qualitative report examines a successful public university program funded by the Avon Foundation to provide scholarship and support services to non-traditional female community college transfer students. Female commuter transfer students often manage multiple roles of parent, student, and employee while attending college. This article identifies how academic and social integration occurs through the provision of scholarships, peer meeting, mentoring, early orientation to academic resources and counseling on personal and academic issues. The findings have implications for the design of university services that could enhance retention among this group of students.
State Anxiety during Watchful Waiting for Urinary Lithiasis
Authors: Kalaitzi C. , Kalantzis A. , Gravas S. , Georgiadis J. , Christodoulou C.
Published: February 2007

Objectives:

Guidelines on many disorders recommend a variable period of watchful waiting between diagnosis and indicated action. In this study, we assessed stress during the watchful waiting period for urinary lithiasis, a benign disorder treated with minimally invasive procedures, without the pitfall of the emotional burden of a terminal or debilitating disease or fear of impending major surgery and to assess the distress caused by waiting per se. Furthermore, we attempt to identify individual patients at risk of prolonged or debilitating psychological distress.

Methods:

A total of 112 lithiasis patients with stones ≤5 mm completed the study. State and trait anxiety were assessed both at baseline and after the end of watchful waiting using STAI, and then they were informed of the indicated action for their case.

Results:

During the 30 days of watchful waiting, patients experienced a significant increase in state anxiety scores, especially if they were male, had high state or trait anxiety scores at baseline, or if they had experienced more than one episode of colicky pain during the waiting period.

Conclusion:

Clinicians should be more flexible when they face the above group of patients, as far as the duration of watchful waiting period is concerned, because a long waiting sets those patients under significant emotional burden.
Aging Prisoners' Concerns toward Dying in Prison
Authors: Aday Ronald H.
Published: February 2007

Prison populations are experiencing rapid increases and many more offenders are dying in prison. This study investigated key variables associated with death anxiety among a group of aging prisoners. For this research, 102 respondents residing in a maximum security prison with a mean age of 59 completed Templer's Death Anxiety Scale. A regression analysis showed that age, inmate social supports, and a number of health related variables were important predictors of death fear. The findings revealed that fear of death is slightly higher among older prisoners than for similar age groups in the community. Qualitative information based on personal narratives found that some inmates see death as an escape, while others expressed fears of dying in prison or the stigma associated with imprisonment.
London through Rose-Colored Graphics: Visual Rhetoric and Information Graphic Design in Charles Booth's Maps of London Poverty
Authors: Kimball Miles A.
Published: February 2007

In this article, I examine a historical information graphic—Charles Booth's maps of London poverty (1889–1902)—to analyze the cultural basis of ideas of transparency and clarity in information graphics. I argue that Booth's maps derive their rhetorical power from contemporary visual culture as much as from their scientific authority. The visual rhetoric of the maps depended upon an ironic inversion of visual culture to make poverty seem a problem that could be addressed, rather than an insurmountable crisis. This visual rhetoric led directly to significant features of and concepts in western societies, including the poverty line and universal old-age pensions (social security).
Patient Characteristics Associated with Participation in a Practice-Based Study of Depression in Late Life: The Spectrum Study
Authors: Gallo Joseph J. , Bogner Hillary R. , Straton Joseph B. , Margo Katherine , Lesho Pat , Rabins Peter V. , Ford Daniel E.
Published: February 2007

Objective:

An important component of generalizing study results to patients is the extent to which study participants adequately represent individuals targeted for the study. The Spectrum study of depression in older primary care patients was utilized to consider patient characteristics associated with nonparticipation.

Method:

Interviewers utilized a validated questionnaire to screen adults aged 65 years and older for depression who presented to one of the participating primary care practices in the Baltimore, Maryland area. Screening interviews included information about sociodemographic factors, functioning, health, and attitudes about depression and its treatment in order to compare participants with persons who declined.

Results:

In all, 2,560 adults aged 65 years and older were screened. Comparison of the characteristics of the patients who were eligible for the study ( n = 773) with patients who participated fully in the in-home evaluation ( n = 355) found that the study sample included proportionately more persons who: 1) were less than 80 years old; 2) completed high school; and 3) reported two or more visits to the practice site within six months of the interview. Among patients who were depressed, no significant differences were found in the characteristics of those who met study eligibility criteria and those who agreed to participate.

Conclusions:

Persons over the age of 80 years of age or those with less than a high school education may require tailored strategies for recruitment even when approached by a trained interviewer in a primary care doctor's office.
Nanotechnology and the Challenges it Poses for the U.S. Federal Government
Authors: Elwood Thomas W.
Published: February 2007

A review and commentary on the knowns and unknowns about nanotechnology effects, perceived dangers, and the role of Government in monitoring, controlling, and protecting its citizens. The lack of a comprehensive approach to assessing emerging technologies that can have an impact on health is emphasized.
Attitude of Health Care Workers to the Involvement of Alternative Healthcare Providers in the Home Management of Childhood Malaria
Authors: Falade Catherine O. , Osowole Oyedunni S. , Adeniyi Joshua D. , Oladepo Oladimeji , Oduola Ayoade M. J.
Published: February 2007

The attitudes of 193 healthcare workers (Nurses (35.7%), auxiliary nurses (35.7%), followed by community health officers (26.4%)) in 55 primary and secondary healthcare facilities to home management of malaria were evaluated in four local government areas in Southwestern Nigeria. Results showed that mothers and patent medicine sellers were perceived as offering useful services in home management of malaria by giving first aid and selling antimalarial drugs, respectively. Although 79% of respondents expressed the opinion that mothers are the most appropriate to give first line management to children suffering from malaria, 56% were also of the view that such children should receive definitive treatment in a formal health care facility. Furthermore, 45% of the respondents felt that only formal healthcare workers should treat children who have malaria irrespective of the location of the treatment because mothers, patent medicine sellers, and traditional healers have not been formally trained. Healthcare workers were willing to train mothers and patent medicine sellers on effective management of childhood malaria, but were not favorably disposed toward collaboration with traditional healers in the home management of malaria. There is an urgent need for formal healthcare workers to seek better understanding of traditional healers' practices as well as their cooperation for improved home management of childhood malaria among indigenous groups.
Racial-Ethnic Differences in Social Anxiety among College Students
Authors: Lesure-Lester G. Evelyn , King Nancy
Published: February 2007

The present study investigated racial-ethnic differences in social anxiety among college students in two-year colleges. The sample consisted of 189 Asian American, African American, White American, and Hispanic American students from two colleges in the Southeast. Participants completed a questionnaire measure of social anxiety. The results indicated that social anxiety was lower for White American and higher for Hispanic American and Asian American students. It was reasoned that racial-ethnic differences in social anxiety might be culturally related and precipitated by varied concerns for racial-ethnic minority groups. These different concerns and implications for counseling students of color were discussed.
Stopping Out and Persisting: Experiences of Latino Undergraduates
Authors: Zurita Martha
Published: February 2007

This study examines the experiences that 10 Latino recent undergraduate students reported having at a large midwestern university. Five persisted through graduation, and five stopped out. Both groups described similar home environments, a lack of social integration, and feelings of academic unpreparedness. Differences among groups were academic difficulties, home-to-school transition, high school segregation, anticipatory socialization, first contact with the university, and education and career goals. The study's implications suggest several approaches to increasing Latino persistence.
Feasibility Study for Collecting Alcohol and other Drug Use Data among Secondary School Students: A Web-Based Survey Approach
Authors: McCabe Sean Esteban , Boyd Carol J. , Young Amy , Crawford Scott
Published: February 2007

This study examined the feasibility of using a Web-based survey to collect alcohol and other drug use data from secondary school students in an urban school district in the Midwest. A Web-based survey was self-administered by a random sample of 6th through 11th grade students in the spring of 2002. The final sample consisted of 1,536 secondary school students (781 women and 755 men). The sample was 57% White, 40% African American, and 3% from other racial and ethnic groups. Several indicators of data quality were examined including response rate, absenteeism, refusals, substantive data, and data processing time. The study achieved a response rate of 89.1%. The results of the present study provide evidence that a Web-based survey can be successfully implemented in an economically and racially diverse urban sample of secondary students. While researchers conducting survey research within secondary schools should consider using Web-based survey approaches, additional research is needed to compare Web-based surveys to more traditional approaches to collecting data.
Perceived Barriers to Health Care Access in a Treated Population
Authors: Bauer Mark S. , Williford William O. , McBride Linda , McBride Katherine , Shea Nancy M.
Published: February 2007

Objective:

Health care access may be a significant contributor to health outcome. However, few data exist on perception of barriers by patients in treatment, and attending a clinic visit does not mean that no barriers exist. Understanding barriers for treated populations is particularly important in optimizing care for high vulnerability populations, such as those with mental illness and the elderly.

Method:

A structured interview, demographic questionnaire, and SF-12 were administered to 324 veterans presenting for primary care or mental health appointments at a Veterans Affairs medical center. Principle components analysis was performed and relationships to vulnerability characteristics were identified.

Results:

Most interview items showed modest mean levels but high variance. Responses were stable over three to six weeks. As hypothesized, perceived total barriers were greater in participants from several vulnerable populations: those receiving treatment for mental health problems, those with disabilities, and those with worse physical and mental function. Minority participants did not perceive greater barriers. An “inverted-U” relationship with age was found. Principal components analysis assigned 18 items across six clinically meaningful subscales. Participants with mental health treatment perceived greater barriers in three subscales including provider communication. Curvilinear relationships were again seen between subscales and age.

Conclusions:

Even individuals “in care” perceive barriers. Members of vulnerable populations, particularly those receiving mental health treatment, perceive greater barriers. Data support a multi-dimensional conceptualization of perceived barriers, and different subgroups experience different patterns of barriers.
Putting Facts over Fears: Examining Childhood Anti-Obesity Initiatives
Authors: Szwarc Sandy
Published: February 2007

Communities and healthcare professionals are calling for a variety of public school anti-obesity initiatives, which need to be approached with caution. With no reliable or accepted clinical measure of obesity in growing children, many children are being inappropriately labeled and stigmatized as fat. The vast majority of children do not have weight problems. While intuitive, these programs are not evidence-based and none to date has proven effective in reducing long-term obesity. But they are resulting in unprecedented levels of body hatred, unhealthy and inappropriate weight loss attempts, fears of food, increased susceptibility to media messages, eating disorders, nutritional deficits, and weight discrimination. This article reviews the evidence surrounding childhood obesity and the health paradigm which has been shown to give lasting positive outcomes for children's health and well-being.
Individualized Treatment Effects of Oxygen Targets in Mechanically Ventilated Critically Ill Adults
Authors: Buell Kevin G. , Spicer Alexandra B. , Casey Jonathan D. , Seitz Kevin P. , Qian Edward T. , Graham Linck Emma J. , Self Wesley H. , Rice Todd W. , Sinha Pratik , Young Paul J. , Semler Matthew W. , Churpek Matthew M.
Published: March 2024

Importance

Among critically ill adults, randomized trials have not found oxygenation targets to affect outcomes overall. Whether the effects of oxygenation targets differ based on an individual’s characteristics is unknown.

Objective

To determine whether an individual’s characteristics modify the effect of lower vs higher peripheral oxygenation-saturation (Spo2) targets on mortality.

Design, Setting, and Participants

A machine learning model to predict the effect of treatment with a lower vs higher Spo2 target on mortality for individual patients was derived in the Pragmatic Investigation of Optimal Oxygen Targets (PILOT) trial and externally validated in the Intensive Care Unit Randomized Trial Comparing Two Approaches to Oxygen Therapy (ICU-ROX) trial. Critically ill adults received invasive mechanical ventilation in an intensive care unit (ICU) in the United States between July 2018 and August 2021 for PILOT (n = 1682) and in 21 ICUs in Australia and New Zealand between September 2015 and May 2018 for ICU-ROX (n = 965).

Exposures

Randomization to a lower vs higher Spo2 target group.

Main Outcome and Measure

28-Day mortality.

Results

In the ICU-ROX validation cohort, the predicted effect of treatment with a lower vs higher Spo2 target for individual patients ranged from a 27.2% absolute reduction to a 34.4% absolute increase in 28-day mortality. For example, patients predicted to benefit from a lower Spo2 target had a higher prevalence of acute brain injury, whereas patients predicted to benefit from a higher Spo2 target had a higher prevalence of sepsis and abnormally elevated vital signs. Patients predicted to benefit from a lower Spo2 target experienced lower mortality when randomized to the lower Spo2 group, whereas patients predicted to benefit from a higher Spo2 target experienced lower mortality when randomized to the higher Spo2 group (likelihood ratio test for effect modification P = .02). The use of a Spo2 target predicted to be best for each patient, instead of the randomized Spo2 target, would have reduced the absolute overall mortality by 6.4% (95% CI, 1.9%-10.9%).

Conclusion and relevance

Oxygenation targets that are individualized using machine learning analyses of randomized trials may reduce mortality for critically ill adults. A prospective trial evaluating the use of individualized oxygenation targets is needed.
Principles of Skin Surgery
Authors: Hussain S. Walayat , Miller Christopher J. , Wang Timothy S.
Published: March 2024

The acquisition of dermatological surgery skills is an integral component of dermatological training. Indeed, the increasing burden of skin cancer has resulted in competence in dermatological surgery being a mandatory requirement for all dermatologists. This chapter provides an overview of the fundamental basics of skin surgery and provides an introduction to more advanced surgical techniques, including Mohs micrographic surgery. This chapter is complemented by high‐quality videos of the surgical techniques discussed and may be accessed via the online version of the textbook.
Principles of Radiotherapy
Authors: Kelly Charles G. , Frew John , Mahtab Najibah
Published: March 2024

Radiotherapy has been used for over a century to treat skin malignancies and still has a curative role to play in a number of different skin pathologies, as well as in adjuvant and palliative settings and where lack of patient fitness or reserve precludes extensive surgery. It is also finding new roles, as in its use in stereotactic radiosurgery for melanoma brain metastases. The potential uses of radiotherapy provide additional options within the multidisciplinary skin cancer team meeting and helps optimise individual skin cancer management plans. Its use is not without morbidities, whose management have also to be considered.
Non‐Syphilitic Bacterial Sexually Transmitted Diseases
Authors: Kinghorn George R. , Gupta Nadi K.
Published: March 2024

Non‐treponemal bacterial sexually transmitted infections, of which gonorrhoea and genital chlamydia are the commonest, have important consequences for maternal and neonatal health worldwide. Transmission is facilitated by their high infectivity and variable periods of asymptomatic carriage. Diagnostic tests have become more sensitive and treatment schedules have recently changed to reflect increasing concerns about antimicrobial resistance. Chancroid has become a sporadic cause of genital ulceration in the UK, usually acquired during travel abroad. Its causative organism,
Haemophilus ducreyi
, is now also recognised in yaws‐like cutaneous lesions in children within isolated communities in tropical countries. Lymphogranuloma venereum has evolved and is now more usually diagnosed as a cause of rectal bleeding resembling inflammatory bowel disease, especially in men who have sex with men, with concomitant HIV infection. Granuloma inguinale has become rare worldwide.
Mycoplasma genitalium
has emerged as another cause of genital tract infection with clinical features similar those of genital chlamydia but where treatment failure is increasing.
Graft‐versus‐host Disease
Authors: Basu Tanya N.
Published: March 2024

Graft‐versus‐host disease is a major complication of allogeneic haematopoietic stem cell transplantation. It is a multiorgan disease process that results from the action of donor‐derived immunocompetent T‐lymphocyte cells against antigens expressed on the cells of the immunocompromised recipient host. The main organs affected are the skin, liver and gastrointestinal tract. Acute, chronic and overlap forms are recognised.
Atopic Eczema
Authors: Ardern‐Jones Michael R. , Flohr Carsten , Reynolds Nick J.
Published: March 2024

Atopic dermatitis is a complex disorder that is highly heritable, but which is strongly influenced by the environment. This chapter reviews the current understanding and describes in detail important concepts in disease pathogenesis in children and adults. Epidemiological understanding, allergy and trigger factors are reviewed. Alongside a comprehensive description of how to optimise topical therapies, phototherapy and the use of classic systemic treatments, we review the most important inflammatory pathways and link these directly to modern therapeutic treatment advances, and the evidence for their effectiveness and safety.
Urticaria
Authors: Grattan Clive E. H. , Sears Alison V.
Published: March 2024

Urticaria is a common illness characterised by itchy weals, angioedema or both. It may be acute (lasting less than 6 weeks) or chronic (lasting 6 weeks or more). Weals and angioedema are characterised by their transient nature and resolve within hours or days without damage. Most acute urticaria is spontaneous and most inducible urticarias are chronic. Several subtypes of inducible urticaria are defined by the provoking stimulus but overlaps between them and spontaneous types occur. The mast cell is central to all types of urticaria and histamine is a major mediator. Allergy may be a cause of acute urticaria but probably never chronic urticaria. Autoimmune and autoallergic aetiologies have been recognised in chronic spontaneous urticaria but the cause remains elusive in many patients and may be multifactorial. Management hinges on identifying a cause or trigger if one can be found, addressing co‐morbidities and optimising pharmacological treatments with antihistamines, omalizumab and other low‐evidence‐based treatments when appropriate to control symptoms. Natural remission can be expected but the illness may be prolonged in some patients.
Adamantiades–Behçet Disease
Authors: Zouboulis Christos C.
Published: March 2024

Adamantiades–Behçet disease (ABD) is a rare, multisystem inflammatory disease of unknown aetiology, classified as a systemic vasculitis and as a neutrophilic dermatosis involving all types and sizes of blood vessels. A genetically determined background with environmental triggering factor(s) are probably involved. A chronic, relapsing, progressive course of oral aphthous ulcers, genital ulcers, skin lesions (papulopustules, erythema nodosum) and iridocyclitis/posterior uveitis is characteristic. ABD is occasionally accompanied by arthritis and vascular, neurological and gastrointestinal manifestations. ABD has a worldwide occurrence with varying prevalence, being endemic in eastern and central Asian and the eastern Mediterranean countries. Characteristic histopathological features of ABD are vasculitis and thrombosis. ABD is not considered contagious. There is no specific mode of Mendelian transmission in ABD. The disease has potentially poor prognosis (especially in males with systemic presenting signs). HLA‐B51 and ERAP‐1 seem to be associated with a more severe prognosis. Immunological mechanisms are considered to play a major role in the pathogenesis of ABD. The disease has currently been classified among the autoinflammatory disorders. The endothelium seems to be the primary target. Diagnosis of ABD is based on clinical signs. The Revised International Criteria for Behçet's Disease provides the most accurate diagnosis. Ophthalmic and neurological sequelae are leading causes of morbidity, followed by severe vascular and gastrointestinal manifestations. Their effects on morbidity may be cumulative. The clinical course of ABD is variable. A multidisciplinary approach in the management of ABD patients is mandatory. The choice of treatment depends on the site and severity of the clinical manifestations of the disease.
Genetic Disorders of Pigmentation
Authors: Morice‐Picard Fanny , Taïeb Alain
Published: March 2024

Differences in skin and hair colour are principally the result of differences in the melanin content of skin. The synthesis of melanin takes place in melanocytes within specialised vesicles known as melanosomes, then distributed to surrounding keratinocytes. Development of skin pigmentation is a complex multistep process that is tightly regulated. Mutations in genes involved in any one of these steps may lead to pigmentary manifestations. Genetic pigmentary disorders provide a way to improve understanding of the development and the regulation of pigmentation.
Chromosomal Disorders
Authors: Rajan Neil , Irvine Alan D. , Mellerio Jemima E.
Published: March 2024

Chromosomal disorders may be due to abnormalities of chromosome number or structure and may involve autosomes or sex chromosomes. Approximately 7.5% of all conceptions have a chromosomal disorder, but most of these are spontaneously aborted, so the birth frequency is 0.6%. Chromosomal abnormalities generally cause multiple congenital malformations. Children with more than one physical abnormality, particularly if developmentally delayed, should undergo chromosomal analysis as part of their investigation. Recent advances for detecting chromosomal aneuploidies leverage the ability of sensitive DNA sequencing technologies to detect fetal (cell free) DNA circulating in the maternal circulation. Invasive diagnostic testing approaches such as chorionic villus sampling or amniocentesis allow access to tissue or amniocytes that can be tested for fetal chromosomal abnormalities. Many chromosomal disorders have cutaneous manifestations. In this chapter we review the cutaneous manifestations of the commonest chromosomal abnormalities.