bluuebunny/crossref_metadata_2025 huggingface dataset:
HIGH‐RESOLUTION AIRBORNE REMOTE SENSING OF BLOOM‐FORMING PHYTOPLANKTON1
Authors: Millie David F. , Baker Michael C. , Tucker Craig S. , Vinyard Bryan T. , Dionigi Christopher P.
Published: October 2004

Remote sensing of highly turbid finfish aquaculture impoundments using the Calibrated Airborne Multispectral Scanner (CAMS) mounted on a Lear jet flown at 900 m was conducted in central Mississippi on 16 May 1990. Concurrent in situ data consisted of phytoplankton pigment concentrations and standing crop, water color, turbidity, and surface‐water temperature. Surface and near‐surface assemblages of cyanophytes and chlorophytes varied dramatically among impoundments; total chlorophyll concentrations and standing crop values ranged from 8 to 483 mg·m−3 and 8.0 × 102 to 2.2 × 106 cells‐mL−1, respectively. Regression models fit to CAMS data provided reliable estimates for and produced accurate digital cartographs of total chlorophyll and carotenoid concentrations, phytoplankton standing crop, and turbidity. Although a model to effectively estimate in situ c‐phycocyanin concentrations was not identified, the lack of a suitable model may have resulted from variability of pigment extraction during quantification rather than failure of remotely sensed imagery to detect c‐phycocyanin. Models derived from imagery of impoundments directly beneath the aircraft sufficiently described in situ parameters in imagery of adjacent series of impoundments not directly below the aircraft. High‐resolution airborne remote sensing provides a means for monitoring local phytoplankton dynamics in temporal and spatial scales analogous to biotic and abiotic processes affecting such dynamics and necessary for applications to ecological research and fisheries or aquacultural management.
INFLUENCE OF PHOSPHORUS NUTRITION ON COPPER TOXICITY TO THREE STRAINS OF SCENEDESMUS ACUTUS (CHLOROPHYCEAE)1
Authors: Twiss Michael R. , Nalewajko Czeslawa
Published: October 2004

Three strains of Scenedesmus acutus f. alternans Hortobagyi with markedly different sensitivities to copper were examined to determine the relative importance of cellular polyphosphate content on acute copper toxicity to photosynthesis. By manipulating the phosphate concentration in semicontinuous cultures, the response of each strain was assessed at three cellular phosphorus states: P‐loaded, P‐sufficient, and P‐deficient. The results demonstrated the importance of cellular polyphosphate content in reducing the toxic effect of copper on photosynthesis; the greater the cellular P content, the less inhibition of photosynthesis occurred during copper exposure. This relationship was evident for both Cu‐tolerant strains (XCu and B‐4) and a Cu‐sensitive strain (X72). The ranges of response to 9.9 μM Cu (measured as the percentage of control rate of photosynthesis within strains) were, from P‐loaded to P‐deficient cells, X72, 78–54%; XCu, 95–77%; and B‐4, 99–94%. The data suggest that polyphosphate plays a passive role in protecting cells from copper; however, with respect to the mechanism of Cu tolerance, polyphosphate appeared to be relatively unimportant because the sensitivity of the Cu‐tolerant strains showed less dependence on cellular polyphosphate than did the Cu‐sensitive strain.
DOESDINOPHYSIS(DINOPHYCEAE) HAVE A SEXUAL LIFE CYCLE?1
Authors: MacKenzie Lincoln
Published: October 2004

A variety of morphotypes (of two size classes) within two wild populations ofDinophysis acutaEhrenberg andD.cf.acuminataare described. The observation that these two cell types engaged in the formation of couplets (possibly leading to the engulfment of the smaller by the larger cell) suggests that these species may undergo a process of sexual reproduction involving the fusion of anisogamous gametes. This behavior and asexual cell division involved a small portion of the population at any one time and took place rapidly at specific subsurface depths and time of day, the former during the evening, the latter during the morning. Even though definite proof of sexuality byDinophysiswas not obtained, the possiblity that sexual dimorphism exists in several species of the genus is discussed.
Heightened condition dependence is not a general feature of male eyespan in stalk-eyed flies (Diptera: Diopsidae)
Authors: Cotton S. , Fowler K. , Pomiankowski A.
Published: October 2004

Stalk-eyed flies are exemplars of sexual selection leading to the evolution of exaggerated male ornaments (eyespan). In Sphyracephala beccarri, there is no evidence for female mate choice for exaggerated male eyespan and only minor sex differences in eyespan. We used S. beccarri to test whether heightened condition dependence only evolves when male eyespan becomes sexually exaggerated. Male eyespan showed heightened condition dependence under food stress compared with a control trait (wing length). However, female eyespan displayed a similar pattern and there was no sex difference in the degree of increased eyespan sensitivity. The finding that eyespan is a sensitive indicator of food stress, even in an unexaggerated state, suggests that this may have acted as a pre-adaptation to the role of eyespan in sexual signalling in other Diopsid species. These results are consistent with handicap theory and Fisher's view of how sexual selection is initiated.
In vitro embryo survival and early viability of larvae in relation to male sexual ornaments and parasite resistance in roach, Rutilus rutilus L.
Authors: Kortet Raine , Vainikka Anssi , Rantala Markus J. , Myntti Janne , Taskinen Jouni
Published: October 2004

According to the ‘good genes’ hypothesis, sexual ornaments provide an indication of the ‘quality’ of the bearer. In roach, Rutilus rutilus, breeding tubercles (BTs) may signal resistance against the digenean parasite, Rhipidocotyle campanula. Life history theory predicts that there should be a trade-off between parasite resistance and other life history traits. In roach, this could imply a trade-off between parasite resistance in mature fish and some larval feature. We studied embryo survival and the early viability of larvae of male roach in relation to expression of BTs and parasite resistance in maternal half-sibling families. Highly ornamented males had higher resistance against R. campanula than less ornamented males, but the BTs were not related to either embryo survival or larval viability. However, sires having higher resistance to R. campanula had lower larval viability. These results suggest that BTs of male roach do not indicate ‘quality’ in terms of early survival or viability, but rather in terms of adult parasite resistance.
Quantitative genetics of sexually dimorphic traits and capture of genetic variance by a sexually-selected condition-dependent ornament in red junglefowl (Gallus gallus)
Authors: Parker T. H. , Garant D.
Published: October 2004

We studied the quantitative genetics of sexually selected traits in a captive population of red junglefowl (Gallus gallus L.) using a multi-generational ‘animal model’ approach. We found significant heritability of mass, tarsus length (both strongly sexually dimorphic), residual mass, and male comb (a fleshy head ornament) length. Residual mass has a genetic correlation between the sexes smaller than unity and so could show partially independent responses to selection in the two sexes. In males, tarsus length and mass were not genetically correlated, and this produced a negative genetic correlation between tarsus length and residual mass. The male red junglefowl's comb, an ornament influencing female choice, is highly condition dependent. We show that expression of this ornament is heritable, however, and shows strong genetic correlation with a condition index, residual mass. Because residual mass is partly influenced by various aspects of condition, it appears that comb size has ‘captured’ genetic variability in condition.
How do natural and sexual selection contribute to sympatric speciation?
Authors: Gourbiere S.
Published: October 2004

I use explicit genetic models to investigate the importance of natural and sexual selection during sympatric speciation and to sort out how genetic architecture influences these processes. Assortative mating alone can lead to speciation, but rare phenotypes’ disadvantage in finding mates and intermediate phenotypes’ advantage due to stabilizing selection strongly impede speciation. Any increase in the number of loci also decreases the likelihood of speciation. Sympatric speciation is then harder to achieve than previously demonstrated by many theoretical studies which assume no mating disadvantage for rare phenotypes and consider a small number of loci. However, when a high level of assortative mating evolves, sexual selection might allow populations to split into dimorphic distributions with peaks corresponding to nearly extreme phenotypes. Competition then works against speciation by favouring intermediate phenotypes and preventing further divergence. The interplay between natural and sexual selection during speciation is then more complex than previously explained.
Costs and benefits of genetic heterogeneity within organisms
Authors: Pineda-Krch M. , Lehtilä K.
Published: October 2004

An increasing number of studies have recently detected within-organism genetic heterogeneity suggesting that genetically homogeneous organisms may be rare. In this review, we examine the potential costs and benefits of such intraorganismal genetic heterogeneity (IGH) on the fitness of the individual. The costs of IGH include cancerous growth, parasitism, competitive interactions and developmental instability, all of which threaten the integrity of the individual while the potential benefits are increased genetic variability, size-specific processes, and synergistic interactions between genetic variants. The particular cost or benefit of IGH in a specific case depends on the organism type and the origin of the IGH. While mosaicism easily arise by genetic changes in an individual, and will be the more common type of IGH, chimerism originates by the fusion of genetically distinct entities, and is expected to be substantially rare in most organisms. Potential conflicts and synergistic effects between different genetic lineages within an individual provide an interesting example for theoretical and empirical studies of multilevel selection.
Women's views and experiences of outpatient hysteroscopy: Implications for a patient‐centered service
Authors: Morgan Myfanwy , Dodds Wendy , Wolfe Charles , Raju Shanti
Published: October 2004

Abstract This study examined women's views and experiences of an invasive outpatient procedure and was undertaken in the context of the UK Government's policy of developing a patient‐centered service. The research was based on a consecutive series of 30 attendees for outpatient hysteroscopy at a London hospital. Pain was recorded using linear analog scales, qualitative semistructured interviews were undertaken and a diary was completed for 3 days following the procedure. Overall pain ratings for 13 women (45%) were classified as a medium to high score. However, nearly all women preferred a future outpatient procedure. A range of factors influenced this preference, including their ability to cope with the pain, the reduced anxiety associated with undergoing the procedure immediately, a dislike of general anesthetics and the convenience of not disrupting usual routines. The psychosocial aspects of care were also identified as important in assisting women to cope, and form a key factor influencing patient's evaluation of services.
Support network of adolescents with chronic disease: Adolescents’ perspective
Authors: Kyngäs Helvi
Published: October 2004

Abstract The purpose of this study was to describe the support network of adolescents with a chronic disease from their own perspective. Data were collected by interviewing adolescents with asthma, epilepsy, juvenile rheumatoid arthritis (JRA) and insulin‐dependent diabetes mellitus (IDDM). The sample consisted of 40 adolescents aged between 13 and 17 years. Interview data were examined using content analysis. Six main categories were established to describe the support network of adolescents with a chronic disease: parents, peers, school, health care providers, technology and pets. Peers were divided into two groups: fellow sufferers and peers without a chronic disease. At school, teachers, school nurses and classmates were part of the support network. Health care providers included nurses, physicians and physiotherapists. Technology was also part of the support network and included four techniques that may be used to communicate: computers, mobile telephones, television and videos. The results provided a useful insight into the social network of adolescents with chronic disease and serve to raise awareness of the problems and opinions experienced by adolescents with this condition.
Liver biopsy complicated by hemorrhage in a patient with ARC syndrome
Authors: Hayes Jason A. , Kahr Walter H.A. , Lo Bryan , Macpherson Bruce A.
Published: October 2004

ARC syndrome is a rare disorder consisting of arthrogryposis, renal tubular acidosis and cholestatic liver disease. We report the case of a 5‐week‐old patient who underwent a percutaneous liver biopsy complicated by hemorrhage, and was subsequently diagnosed with ARC syndrome. A review of the literature demonstrates that these patients are at increased risk of bleeding caused by platelet dysfunction. The evaluation and management of unexpected hemorrhage in pediatric patients as a result of undiagnosed congenital bleeding problems is discussed.
Paradoxical reaction following intravenous midazolam premedication in pediatric patients – a randomized placebo controlled trial of ketamine for rapid tranquilization
Authors: Golparvar Mohammad , Saghaei Mahmood , Sajedi Parvin , Razavi Seid Sajad
Published: October 2004

Background : Paradoxical reactions to benzodiazepines include restlessness, violent behavior, physical assault, act of self‐injury and need for restraints. These may occur at variable times after administration. This study was designed to determine the incidence of paradoxical reactions following intravenous midazolam premedication in pediatric patients and to compare the efficacy of extra doses of midazolam with low‐dose intravenous ketamine to rapidly tranquillize them.

Methods : A total of 706 ASA I, II children scheduled for elective surgery were given intravenous midazolam premedication. Children who developed a paradoxical reaction were randomly divided into three equal groups to receive: (i) extra midazolam, (ii) ketamine, or (iii) placebo as the test drug for treatment of paradoxical reaction. Ease of rapid tranquillization and need for a rescue tranquillizer (i.e. ketamine; irrespective of patient group) were compared among the three groups.

Results : Twenty‐four (3.4%) children developed paradoxical reaction after midazolam premedication. Those who received ketamine as the test drug responded rapidly to ketamine. But the responses of the other two groups to their test drug were poor and the majority of them required ketamine as rescue tranquillizer (six in midazolam, seven in placebo, but no patient in the ketamine group; P < 0.05).

Conclusions : The results of this study demonstrate that ketamine is an effective drug for the treatment of paradoxical reaction following intravenous midazolam premedication. The exact mechanisms of these reactions and how it is aborted by ketamine are not clear.
General anesthesia, surgery and hospitalization in children and their effects upon cognitive, academic, emotional and sociobehavioral development – a review
Authors: Caldas José Carlos S. , Pais‐Ribeiro José Luís , Carneiro Silvestre R.
Published: October 2004

We reviewed current knowledge about cumulative and differential consequences of general anesthesia, surgery and hospitalization upon cognitive, academic, emotional and sociobehavioral development in children. Our strategy was to search the databases Pub Med and PsycINFO for all articles published between 1990 and May 2002. Based on the abstracts, we included all articles that related in any way to our subject of interest. Analysis of the articles showed preoperative anxiety as the main contributing factor to perioperative negative developmental effects. These were generally limited in duration and reversible. Research in this area tries to investigate predictors of increased anxiety, as well as the efficacy of different interventional programs for reduction of preoperative anxiety. We found no studies attempting to differentiate the relative influences of ‘anesthetic stress’, ‘surgical stress’ and ‘hospitalization stress’ on ‘negative outcomes’, ‘areas of development affected’ or ‘duration of effects’. There are very few studies on academic and cognitive consequences. There is a need for more research in this area to provide useful guidelines for clinicians, to identify risk situations and to prevent negative outcomes.
Continuous ventilation technique for laryngeal mask airway (LMATM) removal after fiberoptic intubation in children
Authors: Weiss Markus , Gerber Andreas C. , Schmitz Achim
Published: October 2004

Background : Fiberoptic tracheal intubation through the laryngeal mask airway (LMATM) is a simple technique to establish a safe airway in neonates and infants with a difficult airway. The technique, however, is complicated by the removal of the laryngeal mask from the patient's mouth because of the similarity in length of the LMA and the tracheal tube.

Methods : Several solutions have been presented to stabilize the tracheal tube within the trachea during withdrawal of the LMA. With all these techniques ventilation of the patient is interrupted.

Results : We present a modified technique, using a double tube assembly, which allows uninterrupted ventilation of the patient during withdrawal of the LMA from the patient's mouth.

Conclusions : The technique is simple and safe, can be performed without hurry and carries potential advantages for neonates and children with limited cardiorespiratory reserve.
Cardiac tamponade in a newborn because of umbilical venous catheterization: is correct position safe?
Authors: Önal E. Esra , Saygili Arda , Koç Esin , Türkyilmaz Canan , Okumus Nurullah , Atalay YIldIz
Published: October 2004

Cardiac tamponade is a rare but life‐threatening complication of umbilical venous catheterization in the newborn. Most complications from central venous catheters are related to incorrect position of the catheter and it is emphasized to confirm the position of the catheter tip after placement in order to avoid possible complications. We present an unusual complication of cardiac tamponade because of umbilical venous catheterization in a term newborn which is extremely rare with correct location of the catheter tip at the junction of inferior vena cava and right atrium. We suggest that correct position never guarantees uneventful catheterization in the newborn. In any infant with a central venous catheter in situ who deteriorates clinically, pericardial effusion/cardiac tamponade must be considered and appropriate action taken.
Bilateral consolidation of the lungs in a preterm infant: an unusual central venous catheter complication
Authors: Pignotti Maria Serenella , Messineo Antonio , Indolfi Giuseppe , Donzelli Gianpaolo
Published: October 2004

We describe a case of bilateral parenchymal consolidation with sudden respiratory distress in a preterm baby as a complication of peripherally inserted central catheter (PICC) dislocation. The X‐rays showed bilateral pulmonary consolidation with the catheter tip initially located in the right, and later in the left pulmonary artery. The catheter was withdrawn. As soon as the catheter was repositioned all clinical signs and symptoms disappeared. Neonatologists should consider the possibility of dramatic respiratory distress deriving from PICC dislocation. Careful tip catheter placement and conscientious monitoring may reduce morbidity.
Use of low concentration factor ultrafiltration retentates in reduced‐fat Minas Frescal cheese manufacture: effect on yield and sensory properties
Authors: CUNHA C R , VIOTTO L A , VIOTTO W H
Published: October 2004

The yield and sensory properties of reduced‐fat Minas Frescal cheese made from low concentration factor (CF) retentates were studied. Three different CFs were tested (1.2, 1.5 and 1.8). The chemical compositions of the milk, retentate, whey and cheese were determined, as well as the cheese yield. The cheese moisture content decreased with increasing CF. The cheese yield was significantly dependent on the CF in the same direction as the moisture content. Despite compositional differences among the samples, only the cheese made with a CF of 1.8 presented low sensorial acceptance. CF 1.2 was found to be the optimum value for reduced‐fat Minas Frescal cheese manufacture in the CF range studied.
Fat injections for facial rejuvenation: 17 years experience in 1720 patients
Authors: Dasiou‐Plakida D
Published: October 2004

Background  Autologous adipose tissue has been proved to be an excellent filling material. Fat injections can correct cosmetic defects that are caused by loss of subcutaneous tissue, such as atrophy of the face due to significant weight loss, wrinkles and facial involution due to ageing.

Objective  To evaluate the safety and long‐term results of facial rejuvenation by autologous fat injections using the fine‐needle technique to inject fat and frozen fat for repeating the implantation procedure.

Method  Patients were evaluated clinically and photographically. Extraction, processing and implantation of fat were performed using an anaerobic technique. The fat was harvested by tumescent liposuction, using syringes and small diameter blunt‐tip cannulas (2–3 mm). After washing the collected fat in normal saline it was centrifuged, transferred to small syringes (1–2.5 mL diameter) and then injected subcutaneously using fine needles of 21–23 G. Hypercorrection was avoided, so one or two repetitions of the fat injections were usually necessary, at intervals of at least 1 month, in order to achieve the desired cosmetic result. Using frozen fat simplified repeat fat implantation.

Results  The clinical long‐term follow‐up of 1720 patients up to 17 years is presented. Absorption of the injected fat was estimated at 40–60%. The absorption rate varied a lot in each case. Long‐term follow‐up proved that final correction after two or more repetitions of frozen fat injections, persisted for many years, the longest proved to be more than 12 years.

Conclusions  The advantages of the fine‐needle technique for fat grafting were very important: more accurate and refined work, less painful injections, no scars at needle puncture points, early treatment of small defects, and the facility to treat multiple sites, even the entire face, in one session. There were no major complications. Oedema and sometimes echymoses at the donor site for 6–10 days and slight bruising at the injected areas for 3–5 days are the disadvantages of the procedure.
The ‘beauty’ of skin neurobiology
Authors: Pincelli C , Bonté F
Published: October 2004

The skin is the most densely innervated organ in the body and there is a close relationship between the skin and the nervous system. Most skin cells express receptors for neuromediators (NM) and skin cells themselves are an important source of NM. In particular, human keratinocytes synthesize neurotrophins and endorphins and express their receptors. In addition to neurotrophic activity, NM are involved in skin homeostasis, trophism and stress responses. NM released from keratinocytes also function in a paracrine fashion on other skin cells, such as Langerhans cells, melanocytes and fibroblasts. We discuss the influence of NM on these cells, which may be involved in major cosmetic problems like ageing, baldness and dyspigmentation. Based on this correlation, it seems reasonable to target neural factors for cosmetic purposes.
Do moisturizers work?
Authors: Lodén M
Published: October 2004

Moisturizers are used on large body surfaces to maintain the smoothness of the skin and to break the dry‐skin cycle. Many healthcare professionals and patients overlook the importance of moisturizers and do not consider them to be ‘active’ treatments. However, evidence from clinical and experimental studies shows that moisturizers enhance both the smoothness and hydration of skin.

Different moisturizers have different ingredients, and each may have a different mode of action. Some smooth the skin, others affect barrier function. Some enhance barrier function in both diseased and normal skin. Others impair barrier function in both diseased and normal skin. Defective barrier function may trigger the development of eczema. The composition of a particular moisturizer should reflect its desired therapeutic effect, i.e. a moisturizer to diminish dryness may need different ingredients from those required to improve barrier function. The content of excipients, such as emulsifiers, chelating agents and antioxidants, may have greater impact than is commonly believed.

Greater tailoring of moisturizers will improve their efficacy. Confidence in the therapeutic effects of moisturizers will be enhanced by well‐designed randomized controlled trials.
Surgical approach to benign small papular and dome‐shaped melanocytic naevi on the face
Authors: Tursen U , Kaya T I , Ikizoglu G
Published: October 2004

Patients frequently request removal of benign papular and dome‐shaped naevi for cosmetic or functional reasons. Melanocytic naevi can be removed by elliptical, round, punch or shave excision or destroyed using electrodessication or cryotherapy. Total elliptical excision is probably the most widely used method of removal. If malignancy is suspected, adequate specimens for histological interpretation are required. When malignancy is not suspected, the cosmetic result becomes the first priority. Smaller incisions minimize tissue trauma and so give cosmetically superior results.

Round excision has been recommended for the removal of moles but has not been widely practised. Round excision and punch excision may be better alternatives than conventional fusiform excision of benign dome‐shaped or papular naevi of the face, as more tissue is preserved. Shave excision of naevi may be preferable to elliptical excision in sites where the incidence of hypertrophic scarring is high, as preservation of some thickness of the dermis may result in a more acceptable scar or even avoid a scar entirely. Expedient and simple surgery with excellent cosmetic results can be accomplished by the use of punches. Cryotherapy with cutting or curetting and electrodesiccation combined with shaving have been described.

Round excision may be a better alternative to conventional fusiform or shave excision of benign papular or dome‐shape nevus of the face because it leaves an almost imperceptible scar. In this technique, less skin is excised and histopathological examination can be done.
Antioxidants in dermocosmetology: from the laboratory to clinical application
Authors: Andreassi M , Andreassi L
Published: October 2004

Oxygen situated in cutaneous cells can be activated by light. This makes the integumentary apparatus particularly vulnerable to oxidative damage and is responsible for the immediate cutaneous damage that is the basis of late phenomena, such as photo‐induced ageing and tumours. Thus, the cosmetic industry has undertaken research and development into antioxidant‐based products able to protect the skin from the effect of pro‐oxidizing noxae.

This review re‐examines both antioxidants suitable for dermatological application and skin care products with antioxidant capacity, as well as the laboratory methods used to evaluate the effects and in vivo efficacy of antioxidants.
Anti‐inflammatory vs. inflammatory treatments for actinic keratoses
Authors: Ortonne Jean‐Paul
Published: October 2004

The treatment of actinic keratoses (AKs) provides an important opportunity to prevent the development of squamous cell carcinoma. The recent discovery that cyclo‐oxygenase‐2 (COX‐2) is a potential pharmacological target for skin tumours has prompted interest in using topical nonsteroidal anti‐inflammatory drugs (NSAIDs) as a treatment for AKs.

Topical 3% diclofenac in 2.5% hyaluronic acid gel (Solaraze) is currently the only NSAID licensed for the treatment of AKs. In randomised, double‐blind studies, this therapy was effective in clearing AKs, with the efficacy increasing in proportion to the duration of treatment. Topical 3% diclofenac in 2.5% hyaluronic acid gel was well tolerated, with the vast majority of adverse events rated as mild or moderate. Older treatments, such as fluorouracil, which promotes an inflammatory response, are also effective in treating AKs, but are not acceptable to many patients because of severe irritation. Imiquimod is an alternative inflammatory treatment, which, although highly effective, is expensive and produces severe erythema, erosion and flaking in a large proportion of patients.

Topical anti‐inflammatory agents, such as 3% diclofenac in 2.5% hyaluronic acid gel, can facilitate the early treatment of AKs without the level of severe side‐effects observed with some of the other therapies.
‘Bad hair days’, scalp sebum excretion and the menstrual cycle
Authors: Birch M Pattie , Messenger Andrew
Published: October 2004

Background  Many women complain that their hair is periodically unmanageable, popularly known as ‘bad hair days’ (BHDs). At an anecdotal level BHDs are more common around the time of menstruation and, in view of previous studies reporting menstrual variation in sebum excretion, the authors hypothesised that changes in scalp sebum levels during the menstrual cycle might contribute to perceive differences in hair quality.

Aims  To test whether there is a relationship between BHDs, the menstrual cycle and scalp sebum excretion.

Methods  Thirteen women were studied through three menstrual cycles. Sebum levels on the scalp and forehead were measured twice weekly using a Sebumeter and each subject kept a record of hair quality and hair washing practice.

Results  BHDs occurred throughout the menstrual cycle but were more common during menstruation. There was no discernible variation in sebum levels on the scalp or forehead during the menstrual cycle and there was no correlation between individual mean skin sebum levels and the frequency of BHDs. However, BHDs were more common in those women who washed their hair infrequently, although the association between the frequency of hair washing and BHDs just failed to reach statistical significance (p = 0.06).

Conclusions  BHDs are more common during menstruation and in women who wash their hair infrequently. This may relate to a build‐up of sebum on the hair but menstrual variations in the frequency of BHDs are unrelated to sebum levels.
Return on Educational Investment in Geriatrics Training
Authors: Weeks William B. , Wallace Amy E.
Published: October 2004

The graying of America will increase demand for specialists in geriatric medicine, but the proportion of filled fellowship positions in geriatric medicine has been falling recently. The objective of this study was to examine the financial return of additional training in geriatric medicine for general internists by using survey data from the American Medical Association and standard financial techniques. The return on educational investment over a working lifetime for a third‐year resident in internal medicine who was considering specialty training in geriatric medicine between 1993 and 1999 was calculated.

Physicians self‐identified as geriatricians had lower incomes and lower incomes per hour than age‐matched general internists, although the disparities decreased somewhat over the period examined. Regression modeling suggested that incomes for geriatricians are lower than expected and that this disparity increased in the last 2 years of the study. Some of the income disparities may be attributable to the fact that geriatricians obtain a greater proportion of their total revenue from Medicare than is optimal in the generalist setting. Returns on educational investment for geriatrics training were negative, although less so in recent years. Analysis suggests that the pursuit of additional specialty training in geriatric medicine has a negative financial return. Financial returns and the incentives they create should be carefully considered in meeting the anticipated geriatrics workforce needs of the nation.
Time Since Immigration and Health Services Utilization of Korean‐American Older Adults Living in Los Angeles County
Authors: Sohn Linda , Harada Nancy D.
Published: October 2004

The aim of this study was to characterize ambulatory healthcare utilization of older Korean Americans and its association with length of time since immigration. It was hypothesized that older Korean Americans who were recent immigrants would use outpatient physician visits less often than early immigrants. The data are from the 2000 Korean‐American Health Survey, which assessed the health status and medical needs of Korean Americans living in Los Angeles County. The dependent variable was the number of visits to a physician for check‐up or consultation. Multivariate regression modeling was used to assess the influence of length of time since immigration on the dependent variable controlling for predisposing, enabling, and need variables for a sample of 208 Koreans Americans aged 65 and older. Results indicated that high school education in Korea and health insurance status were significant predictors of number of visits to a physician during the previous year (P<.05). The main variable of interest, the number of years living in the United States, approached significance at P=.09. It was concluded that enabling variables such as education and health insurance significantly influenced use of healthcare services in the older Korean‐American population. The lack of studies regarding older minority populations and their access to healthcare further highlight theneed not only to characterize the access of these often‐vulnerable populations, but also to generate interest for further studies.
Can a Spring Beat the Charges?
Authors: Partensky Michael , Partensky Peretz D.
Published: October 2004

This paper describes the properties of a simple system consisting of two charges, one of which is fixed while the second one, of variable charge q, is suspended on an insulated spring. When the interaction between the charges is attractive and the absolute value of q increases, the system exhibits complex “catastrophic” behavior resulting in a sudden collapse in response to a tiny variation of q near a “critical”value.
A Simple Device for Exploring Optical Activity
Authors: Colicchia Giuseppe
Published: October 2004

When plane-polarized light passes through an optically active material, the plane of polarization is rotated. The angle of rotation depends on the material, its temperature, and the wavelength of the light. It may also be affected by the electric and magnetic fields to which the sample is subjected. In this paper we describe a simple spinning analyzer technique that may be used to study the optical activities of materials. After passing through the sample, a polarized light beam is directed through a continuously rotating polarizing sheet (analyzer). A light detector is used to sense the intensity of the light exiting the analyzer, and the resulting signal may be displayed on an oscilloscope or computer screen and observed by many students simultaneously. With our setup we can make continuous measurements of the rotation angle and can also impressively demonstrate Malus' law.
Exponential Versus Linear Amplitude Decay in Damped Oscillators
Authors: Molina M. I.
Published: October 2004

The problem of oscillatory motion is, without any doubt, one of the main topics in physics from elementary up to advanced courses. An understanding of this motion is also relevant in many areas outside physics, including chemistry, biology, engineering, medical research, and economics to name a few. In physics, students encounter oscillatory behavior in classical mechanics, electricity, optics, and later in quantum mechanics.
Using the Stock Market to Teach Physics
Authors: Faux David A. , Hearn Stephen
Published: October 2004

Students are interested in money. Personal finance is an important issue for most students, especially as they move into university education and take a greater control of their own finances. Many are also interested in stock markets and their ability to allow someone to make, and lose, large sums of money, with their interest fueled by the boom in technology-based stocks of 2000/2001 followed by their subsequent dramatic collapse and the publicizing of so-called “rogue-traders.” There is also a much greater ownership of stocks by families following public offerings, stock-based savings products, and the ability to trade stocks online. Consequently, there has been a steady growth of finance and finance-related courses available within degree programs in response to the student demand, with many students motivated by the huge salaries commanded by those with a successful career in the financial sector. We report here details of a joint project between Charterhouse School and the University of Surrey designed to exploit the excitement of finance to teach elements of the high school (age 16–18) curriculum through modeling and simulation.
Letter to Grandma
Authors: Hicks Jim
Published: October 2004

Each year at the Summer Meeting, AAPT honors the contributions of exceptional physics teachers by presenting Excellence in Teaching awards. This year's winner for Excellence in Pre-College Teaching is James (Jim) Hicks from Barrington High School in Barrington, IL. In his acceptance speech, Jim described his primary goal in teaching as encouraging students to be “drivers instead of passengers” on the road to learning physics. As he shared techniques designed to move students from concrete reasoning to abstract thinking and problem solving, I quickly saw why he was being recognized for excellence in teaching. I don't think a student could be in Jim's class and not discover the fun in physics while developing an understanding of the relevance of physics principles to everyday life. Described below is one of Jim's favorite assessment techniques.
ON THE PHYSICO-CHEMICAL THEORY OF BIOLOGICAL EVOLUTION
Authors: GLADYSHEV G.P. , GLADYSHEV D.P.
Published: October 2004

The present paper deals with the experimental identification of previously postulated correlations linking the specific Gibbs function of the formation of supramolecular structures of living organisms with the chemical energy capacity or the relative thermodynamic stability of the substances involved in the self-assembly of these structures. The paper presents new results to further corroborate the macrothermodynamic model of the evolution of biological systems as applied to phylogenesis, ontogenesis as well as the extended periods of the general evolution of life forms.
THE DESIGN OF AN ADAPTIVE MULTIPLE AGENT FUZZY CONSTRAINT-BASED CONTROLLER (MAFCC) FOR A COMPLEX HYDRAULIC SYSTEM
Authors: TYAN CHING-YU , WANG PAUL P. , BAHLER DENNIS R.
Published: October 2004

In this paper, we present a complete design framework for an adaptive multiple agent fuzzy constraint-based controller (MAFCC) based on fuzzy penumbra constraint processing in each fuzzy constraint subnetwork collaborating with a connected constraint network and its corresponding semantic modeling in a first-order predicate calculus (FOPC) language, with application to a complex hydraulic system. The concept of “multiple agent” and “fuzzy constraint subnetwork” in a complex control system is introduced and some basic definitions of penumbra fuzzy constraint processing in a constraint subnetwork and the collaboration with an overall connected constraint network and its semantic modeling are addressed. As a result, a human agent interacts with system agents and allows the constraints to be added or deleted on-line according to the constraints imposed from the outside environment. Near-optimal system performance is accomplished by restricting all the penumbra constraints to be satisfied in each constraint subnetwork simultaneously which are interconnected as a result of constraints that exist between each of them. Following the principle of constraint satisfaction and fuzzy local propagation reasoning, each individual system agent is now constrained to behave in a certain fashion as dictated by the overall constraint network. In addition, the constraint network in MAFCC system provides an update strategy which makes a real time adaptive hydraulic control for all 20 cities possible.
Early fluid retention and severe acute mountain sickness
Authors: Loeppky Jack A. , Icenogle Milton V. , Maes Damon , Riboni Katrina , Hinghofer-Szalkay Helmut , Roach Robert C.
Published: October 2004

Field studies of acute mountain sickness (AMS) usually include variations in exercise, diet, and environmental conditions over days and development of clinically apparent edemas. The purpose of this study was to clarify fluid status in persons developing AMS vs. those remaining without symptoms during simulated altitude with controlled fluid intake, diet, temperature, and without exercise. Ninety-nine exposures of 51 men and women to reduced barometric pressure (426 mmHg = 16,000 ft. = 4,880 m) were carried out for 8–12 h. AMS was evaluated by Lake Louise (LL) and AMS-C scores near the end of exposure. Serial measurements included fluid balance, electrolyte excretions, and plasma concentrations, regulating hormones, and free water clearance. Comparison between 16 subjects with the lowest AMS scores near the end of exposure (“non-AMS”: mean LL = 1.0, range = 0–2.5) and 16 others with the highest AMS scores (“AMS”: mean LL = 7.4, range = 5–11) demonstrated significant fluid retention in AMS beginning within the first 3 h, resulting from reduced urine flow. Plasma Na+ decreased significantly after 6 h, indicating dilution throughout the total body water. Excretion of Na+ and K+ trended downward with time in both groups, being lower in AMS after 6 h, and the urine Na+-to-K+ ratio was significantly higher for AMS after 6 h. Renal compensation for respiratory alkalosis, plasma renin activity, aldosterone, and atrial natriuretic peptide were not different between groups, with the latter tending to rise and aldosterone falling with time of exposure. Antidiuretic hormone fell in non-AMS and rose in AMS within 90 min of exposure and continued to rise in AMS, closely associated with severity of symptoms and fluid retention.
Activation of phosphatidylinositol 3-kinase, Akt, and mammalian target of rapamycin is necessary for hypoxia-induced pulmonary artery adventitial fibroblast proliferation
Authors: Gerasimovskaya Evgenia V. , Tucker Doug A. , Stenmark Kurt R.
Published: October 2004

In contrast to cell types in which exposure to hypoxia causes a general reduction of metabolic activity, a remarkable feature of pulmonary artery adventitial fibroblasts is their ability to proliferate in response to hypoxia. Previous studies have suggested that ERK1/2, phosphatidylinositol 3-kinase (PI3K), Akt, and mammalian target of rapamycin (mTOR) are activated by hypoxia and play a role in a variety of cell responses. However, the pathways involved in mediating hypoxia-induced proliferation are largely unknown. Using pharmacological inhibitors, we established that PI3K-Akt, mTOR-p70 ribosomal protein S6 kinase (p70S6K), and EKR1/2 signaling pathways play a critical role in hypoxia-induced adventitial fibroblast proliferation. We found that exposure of serum-starved fibroblasts to 3% O2resulted in a time-dependent activation of PI3K and transient phosphorylation of Akt. However, activation of PI3K was not required for activation of ERK1/2, implying a parallel involvement of these pathways in the proliferative response of fibroblasts to hypoxia. We found that hypoxia induced significant increases in mTOR, p70S6K, 4E-BP1, and S6 ribosomal protein phosphorylation, as well as dramatic increases in p70S6K activity. The activation of p70S6K/S6 pathway was sensitive to inhibition by rapamycin and LY294002, indicating that mTOR and PI3K/Akt are upstream signaling regulators. However, the magnitude of hypoxia-induced p70S6K activity and phosphorylation suggests involvement of additional signaling pathways. Thus our data demonstrate that hypoxia-induced adventitial fibroblast proliferation requires activation and interaction of PI3K, Akt, mTOR, p70S6K, and ERK1/2 and provide evidence for hypoxic regulation of protein translational pathways in cells exhibiting the capability to proliferate under hypoxic conditions.
Ascorbic acid does not affect the age-associated reduction in maximal cardiac output and oxygen consumption in healthy adults
Authors: Bell Christopher , Carson John M. , Motte Nathaniel W. , Seals Douglas R.
Published: October 2004

Maximal aerobic capacity (V̇o2max) decreases progressively with age, primarily because of a reduction in maximal cardiac output (Q̇max). This age-associated decline in V̇o2max may be partially mediated by the development of oxidative stress that can suppress β-adrenergic-receptor responsiveness and, consequently, reduce Q̇max. To test this hypothesis, V̇o2max (indirect calorimetry) and Q̇max (open-circuit acetylene breathing) were determined in 12 young (23 ± 1 yr, mean ± SE) and 10 older (61 ± 1 yr) adults following systemic infusion of either saline (control) and/or the powerful antioxidant ascorbic acid (acute: bolus 0.06; drip 0.02 g/kg fat-free mass) and following chronic 30-day oral administration of ascorbic acid (500 mg/day). Plasma ascorbic acid concentration was not different between young and older adults and was increased similarly, independent of age [change (Δ) acute = 1,055 ± 117%; Δ chronic = 62 ± 19%]. Oxidized low-density lipoprotein concentration was greater ( P < 0.001) in older (57 ± 5 U/l) compared with young (34 ± 3 U/l) adults and was reduced in both groups ( P < 0.02) following acute (Δ = −6 ± 2%) but not chronic ( P = 0.18) ascorbic acid administration. Control (baseline) V̇o2max and Q̇max were positively related ( r = 0.76, P < 0.001) and were lower ( P < 0.05) in older (34 ± 2 ml·kg−1·min−1; 16.1 ± 1.1 l/min) compared with young (43 ± 3 ml·kg−1·min−1; 20.2 ± 0.9 l/min) adults. Following ascorbic acid administration, neither V̇o2max (young acute = 41 ± 2; young chronic = 42 ± 2; older acute = 34 ± 2; older chronic = 34 ± 2 ml·kg−1·min−1) nor Q̇max (young acute = 20.1 ± 0.9; young chronic = 19.1 ± 0.8; older acute = 16.2 ± 1.1; older chronic = 16.6 ± 1.4 l/min) was changed. These data suggest that ascorbic acid administration does not affect the age-associated reduction in Q̇max and V̇o2max.
Anatomically based three-dimensional model of airways to simulate flow and particle transport using computational fluid dynamics
Authors: van Ertbruggen Caroline , Hirsch Charles , Paiva Manuel
Published: October 2004

We have studied gas flow and particle deposition in a realistic three-dimensional (3D) model of the bronchial tree, extending from the trachea to the segmental bronchi (7th airway generation for the most distal ones) using computational fluid dynamics. The model is based on the morphometrical data of Horsfield et al. (Horsfield K, Dart G, Olson DE, Filley GF, and Cumming G. J Appl Physiol 31: 207–217, 1971) and on bronchoscopic and computerized tomography images, which give the spatial 3D orientation of the curved ducts. It incorporates realistic angles of successive branching planes. Steady inspiratory flow varying between 50 and 500 cm3/s was simulated, as well as deposition of spherical aerosol particles (1–7 μm diameter, 1 g/cm3 density). Flow simulations indicated nonfully developed flows in the branches due to their relative short lengths. Velocity flow profiles in the segmental bronchi, taken one diameter downstream of the bifurcation, were distorted compared with the flow in a simple curved tube, and wide patterns of secondary flow fields were observed. Both were due to the asymmetrical 3D configuration of the bifurcating network. Viscous pressure drop in the model was compared with results obtained by Pedley et al. (Pedley TJ, Schroter RC, and Sudlow MF. Respir Physiol 9: 387–405, 1970), which are shown to be a good first approximation. Particle deposition increased with particle size and was minimal for ∼200 cm3/s inspiratory flow, but it was highly heterogeneous for branches of the same generation.