bluuebunny/crossref_metadata_2025_split huggingface dataset:
Why birds sing at dawn: the role of consistent song transmission
Authors: Brown Timothy J. , Handford Paul 
Published: March 2003

The dawn chorus is a widely observed phenomenon. One of the common, but inadequately studied, explanations for the occurrence of the dawn chorus is based on the rationale that atmospheric turbulence, which impairs acoustic communication, is least at dawn, and thus singing at dawn in some way maximizes signal performance. To investigate what possible acoustic benefit is gained through singing at dawn, we transmitted Swamp Sparrow Melospiza georgiana and White‐throated Sparrow Zonotrichia albicollis song through open grassland and closed forest both at dawn and at midday. The transmitted songs were re‐recorded at four distances from 25 to 100 m. Our results show that the mean overall absolute transmission quality of the signals was not significantly better at dawn than at midday. However, the signal transmission quality was significantly more consistent at dawn than at midday. Also, in general, signal transmission quality decreased with increasing distance. Variability in the transmission quality increased with distance for the White‐throated Sparrow song, but not for the Swamp Sparrow song. Consistency in signal transmission quality is a factor that, arguably, is crucial for the identity function of song. This study strongly supports the acoustic transmission hypothesis as an explanation for the existence of the dawn chorus while the demonstration of variability as a key factor in singing at dawn is novel.
Repeatability of subjective refraction in myopic and keratoconic subjects: results of vector analysis
Authors: Raasch Thomas W. , Schechtman Kenneth B. , Davis Larry J. , Zadnik Karla ,   The CLEK Study Group
Published: March 2003

SummaryThis paper evaluates the repeatability of refraction in keratoconus patients and normal myopes, using representations of spherocylindrical power that are theoretically valid. Data consist of test–retest refraction data from the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study and similar data from normal myopes. Dioptric powers are transformed to an orthogonal vector representation of dioptric power. The metric of change is the dioptric difference between test and retest. The median difference between test and retest in keratoconus patients is four to six times larger than in normal myopes. Refraction over a rigid contact lens on a keratoconic cornea improves repeatability but remains approximately twice as large as in normal myopes. The methods demonstrated here possess advantages over previous methods and provide a more valid comparison between test and retest and between different subject groups. The repeatability of refraction in keratoconus patients is substantially worse than in normal myopes.
Referral rates for a functional vision screening among a large cosmopolitan sample of Australian children
Authors: Junghans Barbara , Kiely Patricia M. , Crewther David P. , Crewther Sheila Gillard 
Published: March 2003

The aim of this study was to investigate the incidence of functional vision problems in a large unselected cosmopolitan population of primary school‐age children and to investigate whether constant clinical criteria for functional vision problems would be implemented by the practitioners involved in the screening. Refractive errors, near point of convergence, stereopsis, strabismus, heterophoria and accommodative facility were assessed for 2697 children (3–12 years) of varying racial backgrounds living in Australia. The spherical component of the refractive error ranged from −7.75 to +9.50 D (mean +0.54 D, ±0.79) with a distribution skewed towards hypermetropia; astigmatism ranged from 0 to 4.25 D (mean −0.16 D, ±0.35). There was a trend towards less hypermetropia and slightly more astigmatism with age. Mean near point of convergence was 5.4 ± 2.9 cm, heterophoria at far and near was 0.12 ± 1.58Δ exophoria and 1.05 ± 2.53Δ exophoria, respectively, 0.55% of children exhibited vertical phoria at near >0.5Δ, accommodative facility ranged from 0 to 24 cycles per minute (cpm) (mean 11.2 cpm, ±3.7), stereopsis varied from 20 to 800 s (′′) of arc with 50% of children having 40′′ or better. The prevalence of strabismus was particularly low (0.3%).Twenty percent of the children were referred for further assessment based on criteria of one or more of: stereopsis >70′′, accommodative facility <8 cpm, near point of convergence (NPC) >9 cm, near exophoria >10Δ or near esophoria >5Δ, shift in eso or exophoria ≥ 4Δ between distance and near, astigmatism ≥ 1 D, myopia more than −0.75 D, or hyperopia >+1.50 D. Post‐hoc analysis of the record cards seeking the reason for further assessment indicates that referrals appear to have been based upon clinical intuition rather than on a set number of borderline or unsatisfactory results.
A multi‐centre study of lapsed contact lens wearers
Authors: Young Graeme , Veys Jane , Pritchard Nicola , Coleman Sarah 
Published: March 2003

AbstractPurpose:  Discontinuation from contact lens wear has been identified as a contributing factor in the lack of growth of contact lens use in Europe. The purpose of this study was to determine the proportion of lapsed contact lens wearers that can be refitted successfully with contact lenses and to evaluate the reasons for discontinuation from contact lens wear.Methods:  This was a multi‐site clinical study involving 15 UK investigators and 236 lapsed contact lens wearers who had previously tried contact lenses and discontinued. The reasons for discontinuation were assessed by subjects, who were then refitted with contact lenses. Investigators subsequently evaluated factors associated with their initial discontinuation. Short‐term success was defined as the successful completion of 1 month of contact lens wear with absence of complications that would prevent further wear. Subjects were interviewed by telephone 6 months after being refitted to determine whether they were still wearing contact lenses. Those who were not wearing lenses were questioned about the reasons for discontinuation and their likelihood of resuming lens wear.Results:  A majority of subjects (51%) cited discomfort as the principal reason for having previously given up contact lens wear. Problems with vision were the second most common reason (13%), either with reading (6%) or general vision (7%). The most common type of discomfort was dryness (40%). In almost all cases (97%), the investigator's assessment of the reasons for discontinuation agreed with the subject's own assessment but investigators also cited product‐related and practitioner‐related factors as contributing to previous failure. The short‐term success rate for refitting lapsed wearers was found to be 77% (CI: 70–82%). The highest short‐term success rates were for 2‐weekly/monthly soft spherical lenses (91%) and daily disposable lenses (89%). Lower success rates were found for soft toric (69%) and soft bifocal (53%) lenses. At the 6‐month stage, 73% of those who continued in lenses after the 1‐month visit were still wearing contact lenses and a further 18% indicated that they were either ‘very likely’ or ‘likely’ to resume lens wear.Conclusions:  A high proportion of lapsed contact lens wearers can be successfully refitted with contact lenses. The prime reason for previous discontinuation from contact lenses is discomfort and, in particular, dryness‐related discomfort. In many cases, previous contact lens failure is product or practitioner‐related rather than because of patient‐specific problems. Once refitted with contact lenses, lapsed wearers cite vision problems rather than discomfort as the most common reason for discontinuing. This finding suggests that recent advances in contact lens material, design, replacement frequencies and care systems have improved the prospects for avoiding lens‐related discomfort and for continuing contact lens wear.
Efficacy of treatment for convergence insufficiency using vision therapy
Authors: Adler Paul 
Published: March 2003

AbstractPurpose: The purpose of this study was to determine if vision therapy (VT), as practised within the constraints of UK optometric practice, employing graded routine eye exercises, is as an effective method for treatment of convergence insufficiency (CI) as previously published data suggest. The study also evaluates the associated symptoms before and after therapy.Methods: As many optometrists diagnose CI solely on the basis of near point of convergence (NPC) and treat only when symptoms are present (Letourneau et al., 1979; Rouse et al., 1997), in this study CI was defined as NPC of 10 cm or greater (either with or without the presence of asthenopic symptoms for near work) accompanied by exophoria greater at near than at distance. The effect of treatment by optometric vision therapy (OVT) on the NPC and number of symptoms was investigated for 92 patients by retrospectively reviewing the clinical records. Success was defined as the restoration of NPC to normal values and significant reduction in the presenting symptoms.Results: The effect of treatment on the NPC was shown to be highly significant (t = 14.61, p < 0.001). Although treatment times were slightly longer, the success rates were higher than reported by other authors. Post‐treatment values for NPC were: <10 cm (98.9%), <8.5 cm (95.7%) and <6.5 cm (80.4%). Longer treatment times were noted for patients who complained that the text appeared to move (χ2, p = 0.007).Conclusion: Vision therapy is an effective method for treatment of CI.
Stereoacuity versus fixation disparity as indicators for vergence accuracy under prismatic stress
Authors: Kromeier Miriam , Schmitt Christina , Bach Michael , Kommerell Guntram 
Published: March 2003

AbstractBackground: Fixation disparity has been widely used as an indicator for vergence accuracy under prismatic stress. However, the targets used for measuring fixation disparity contain artificial features in that the fusional contours are thinned out. We considered that stereoacuity might be a preferable indicator of vergence accuracy, as stereo targets represent natural viewing conditions.Methods: We measured fixation disparity with a computer adaptation of Ogle's test and stereoacuity with the automatic Freiburg Stereoacuity Test. Eight subjects were examined under increasing base‐in and base‐out prisms.Results: The response of fixation disparity to prismatic stress revealed the curve types described by Ogle and Crone. All eight subjects reached a stereoscopic threshold below 10 arcsec. In seven subjects the stereoscopic threshold increased before double vision occurred.Conclusion: Our data suggest that stereoacuity is suitable to assess the range of binocular vision under prismatic stress. As stereoacuity bears the advantage over fixation disparity in that it can be measured without introducing artificial viewing conditions, we suggest exploring whether stereoacuity under prismatic stress would be more meaningful in the work‐up of asthenopic patients than is fixation disparity.
Important Relationships Between Diet, Nutrition, and Oral Health
Authors: Palmer Carole A. 
Published: March 2003

AbstractNutritional factors are important for dental health. Diet and nutritional status contribute to the development of caries, periodontal disease, osteoporosis, and other conditions. Primary care clinicians can play an important role in the maintenance of oral health; likewise, dentists should not neglect nutritional issues. This review describes the role of various nutritional factors on oral health; special concerns for pregnant women, infants, toddlers, children, adolescents, adults, and elders; and specific oral health concerns of individuals with various medical conditions.
The Continuity of Nutrition Care Through Liver Transplantation
Authors: Vintro Andrea Q. 
Published: March 2003

AbstractRecent advancements in pharmacotherapies and medical technologies have significantly improved long‐term survival rates after liver transplantation. However, as survival rates increase, so do incidences of other chronic diseases more commonly associated with advanced age. In fact, as a population, post‐liver‐transplant patients are at greater risk for cardiovascular disease, diabetes mellitus, cancer, and osteoporosis than the general public. Moreover, disease risk factors such as hyperglycemia, dyslipidemia, hypertension, and excess weight gain continue to plague this population despite reduced‐dose requirements for immunosuppressives—a class of drugs with numerous side effects—which, historically, were thought to contribute heavily to chronic disease risk. Thus, clinicians treating liver‐transplant candidates are challenged to broaden the scope of their care to include prevention of other chronic diseases that may have strong nutritional components. Although nutrition and medical therapies should continue to treat specific symptoms associated with the stages of liver disease and transplantation, therapies and information provided to pre‐transplant patients should include preventative measures to ensure optimal outcomes for improved longevityaftertransplant. The medical team should utilize the nutritional expertise of dietitians to lead this continuity of care through all stages of liver transplantation. To maximize longevity and quality of life, dietary intervention for chronic disease prevention should be implemented as soon as medically feasible. This paper reviews nutrition therapies for complications seen during liver transplantation and proposes individualized diet recommendations to be considered at the very earliest stages of caring for patients with liver disease.
Nutritional Factors in the Control of Blood Pressure and Hypertension
Authors: Suter Paolo M. , Sierro Christophe , Vetter Wilhelm 
Published: March 2003

AbstractDiffering hypertension prevalence rates between certain population and age groups are partially due to differences in the intake of certain nutrients. Blood pressure is positively associated with higher sodium, alcohol, and protein intakes; it is inversely associated with potassium, calcium, and magnesium intakes. Salt may lead to an increase in blood pressure in the presence of salt sensitivity, but there is no inexpensive or easy strategy to identify salt‐sensitive patients. Other risk factors for hypertension include obesity and lack of regular physical activity.The best strategy appears to be moderate salt restriction (6–7 g/day) in combination with an optimal compliance of the antihypertensive drug therapy, as well as adoption of the combination diet of the DASH study—a diet rich in fruits and vegetables, and thus rich in potassium. Current evidence does not support the increased intake of Ca2+ or Mg2+ for blood‐pressure‐lowering purposes only; however, calcium and magnesium may represent important components in the combination diet of the DASH study. It seems that it is the combination of these nutrients that is of crucial importance for the achievement of optimal blood‐pressure reduction. Also recommended is a decrease in alcohol consumption and an increase in regular physical activity. Instead of a severe intervention with regard to 1 risk factor alone, positive changes in 5 habits combined—high salt intake, high sodium‐to‐potassium ratio, alcohol intake, calorie imbalance, and a sedentary life—may be the most realistic and effective strategy to counteract the present hypertension epidemic.
Regional variation in exhumation and strain rate of the high‐pressure Sambagawa metamorphic rocks in central Shikoku, south‐west Japan
Authors: Yagi K. , Takeshita T. 
Published: March 2003

AbstractRegional variation in the P–T path of the Sambagawa metamorphic rocks, central Shikoku, Japan has been inferred from compositional zoning of metamorphic amphibole. Rocks constituting the northern part (Saruta River area) exhibit a hairpin type P–T path, where winchite/actinolite grew at the prograde stage, the peak metamorphism was recorded by the growth of barroisite to hornblende and sodic amphibole to winchite/actinolite grew at the retrograde stage. In the southern part (Asemi River area), rocks exhibit a clockwise type P–T path, where barroisite to hornblende core is rimmed by winchite to actinolite. The difference in P–T path could suggest a faster exhumation rate (i.e. more rapid decompression) in the southern than in the northern part. On the other hand, physical conditions of deformation during the exhumation stage have been independently inferred from microstructures in deformed quartz. Recrystallized quartz grains in rocks from the low‐grade (chlorite and garnet) zones are much more stretched in the southern part (aspect ratio ≥ 4.0) than in the northern part (aspect ratio< 4.0), indicating a higher strain rate in the former than in the latter. These facts may indicate that the exhumation and strain rates are correlated (i.e. the exhumation rate increases with increasing the strain rate). The difference in the exhumation rate inferred from amphibole zoning between the northern and southern parts could be explained by an extensional model involving normal faulting, where the lower plate can be exhumed faster than the upper plate due to the displacement along the fault. Furthermore, the model may explain the positive correlation between the exhumation and strain rates, because the lower plate tended to support more stress than the upper plate.
Indications for Vancomycin in Dialysis Patients
Authors: Golper Thomas A. , Schulman Gerald , D'agata Erika M. C. 
Published: March 2003

ABSTRACTResistance to vancomycin has emerged among Staphylococcus aureus, coagulase‐negative staphylococci (CNS), and enterococci, and this emergence has particular prevalence in dialysis units. It has therefore become imperative that physicians use vancomycin judiciously. General recommendations regarding the appropriate use of vancomycin have been developed. Although in theory implementation of these guidelines should not be difficult, the medical community may be unable or unwilling to make the necessary adjustments in practice. The onslaught of cost constraints and bureaucratic encumbrance has occurred simultaneously with the increase in vancomycin resistance among pathogens commonly isolated among the dialysis population. When a patient responds to empiric antibiotic therapy and susceptibility data indicate that an antibiotic other than vancomycin would be appropriate, the clinician far too often does not make the change to this alternative. Previously there was no biological imperative to change the antibiotic. That complacency has infected an entire generation of physicians, and especially nephrologists. Furthermore, there is an active movement against change, driven by concerns such as malpractice accusations and frank errors in the interpretation of medical facts.
Role of β2‐Microglobulin in the Immune Response in Renal Osteodystrophy
Authors: Balint Eva 
Published: March 2003

ABSTRACTRenal osteodystrophy is the major cause of skeletal morbidity in dialysis patients. It is characterized by β2‐microglobulin (β2M) amyloid deposition at the osteoarticular sites and a destructive arthropathy. β2M is present on the surface of all nucleated cells as the small extracellular subunit of the major histocompatibility complex (MHC) class I molecule and actively participates in the immune response. Accumulating evidence suggests that β2M plays a key role in the development of renal osteodystrophy through a T cell‐mediated inflammatory immune mechanism.
How Important Is Atheromatous Renal Artery Stenosis as a Cause of End‐Stage Renal Disease?
Authors: Main John 
Published: March 2003

ABSTRACTIn recent years atheromatous renal artery stenosis has been proposed as a common and potentially preventable cause of end‐stage renal disease (ESRD). Occlusive renal artery disease causes renal failure that can be reversed following successful revascularization, but this scenario is relatively rare. Nonocclusive renal artery stenosis is commonly found in association with varying degrees of renal impairment. However, recent evidence and clinical observation suggest that a cause and effect relationship is unlikely. Experimentally, split renal function studies in cases of unilateral stenosis find similar degrees of renal impairment in both kidneys. Clinically, severe renal impairment is often found in the presence of unilateral stenoses. Another nephropathic process must be going on, probably a combination of hypertensive and atheroembolic damage. It is not surprising that the two pathologies often coexist, in view of their shared causes (principally hypertension and tobacco smoking). Previous studies of the importance of renal artery stenosis in causing ESRD probably included many cases of hypertensive and atheroembolic nephropathy. Unfortunately the potential for renal revascularization to prevent ESRD has been exaggerated.
The Dialysis Outcomes and Practice Patterns Study (DOPPS): How Can We Improve the Care of Hemodialysis Patients?
Authors: Goodkin David A. , Mapes Donna L. , Held Philip J. 
Published: March 2003

ABSTRACTOutcomes among dialysis patients vary considerably internationally and across regions within the United States. The Dialysis Outcomes and Practice Patterns Study (DOPPS) is a large, prospective, observational study of representative samples of hemodialysis patients in France, Germany, Italy, Japan, Spain, the United Kingdom, and the United States. The DOPPS collects a wealth of data regarding the patients' demographic characteristics, medical histories, laboratory values, prescriptions, dialysis unit practices, and outcomes. The study seeks to clarify which dialysis practices contribute to improved mortality rates, hospitalization rates, health related quality of life, and vascular access outcomes, after adjusting for the effects of comorbid disease and demographic variables. Over 18,000 patients have been enrolled to date. This paper describes the initial findings and outlines the plans to expand the trial.
Renal Transplantation Update Series Editor: V. Ram Peddi and M. Roy First: Recent Advances in Immunosuppressive Therapy for Renal Transplantation
Authors: Peddi V. Ram , First M. Roy 
Published: March 2003

ABSTRACTRecent advances in immunosuppression have focused on more effective, safer, and targeted therapies that have resulted in improved short‐ and intermediate‐term renal allograft survival. During the past decade there has been a marked decrease in acute rejection rates following renal transplantation because of the use of newer immunosuppressive agents. Recent data indicate that the average yearly reduction in the relative hazard of graft failure beyond 1 year was 4.2% for all recipients (0.4% for those recipients who had an acute rejection episode and 6.3% for those who did not have an acute rejection). Despite these improvements the currently available immunosuppressive agents are associated with significant cardiovascular risk factors, an increased risk of infection, and the development of malignancies in the long term. Predictive parameters of donor‐specific hyporesponsiveness are needed so as to allow identification of patients in whom immunosuppressive therapy can be safely reduced. Immunosuppressive agents that have recently been approved for use in the United States and those that are in clinical and preclinical studies are discussed.