bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphological evolution in a hyperdiverse clade: the ant genus Pheidole
Authors: Pie M. R. , Traniello J. F. A. 
Published: September 2006

AbstractUnderstanding patterns of morphological variation and their evolutionary causes is among the main goals of evolutionary biology. In this paper we analyse the pattern of morphological variation in the hyperdiverse ant genus Pheidole (Hymenoptera: Formicidae). We describe the morphospace defined by 231 Pheidole species in the New World using 18 linear quantitative characters. The first ordination axis of the morphospace was found to mainly reflect differences in body size, which explained 83.2 and 78.6% of all morphological variation in minor and major worker subcastes, respectively. Therefore, despite considerable morphological divergence among Pheidole species, most of this variation can be attributed to allometric changes along a size axis, leaving little opportunity for ecological specialization that might be reflected in the studied morphological traits. Simulations suggest that this degree of concentration of variance on the first principal component is unlikely to be due solely to shared phylogenetic history. The second ordination axis reflected mostly variation in head characters, most notably antennal scape length. The third ordination axis described aspects of alitrunk and petiole shape. Although generally concordant, the loading patterns in the second and third axes differed between minors and majors, suggesting different selective pressures affecting the evolution of each subcaste. These general trends in shape were confirmed by additional analyses that corrected for body size. Ordination analyses were complemented by comparing patterns of interspecific morphological covariation in minors and majors of Pheidole using newly developed analyses based on the statistical concept of conditional independence of Magwene. A comparison between worker subcastes indicated substantial reorganization in the pattern of character covariation, particularly through a decrease in character‐correlation levels (dissociation). Moreover, graphical modelling indicated correlations between characters in widely different parts of the body, suggesting that the opportunity for morphological evolution in Pheidole appears to be surprisingly limited. This result might explain why morphological evolution in Pheidole has been highly conservative in spite of substantial ecological diversification.
Factors affecting juvenile survival in African wild dogs (Lycaon pictus) in Kruger National Park, South Africa
Authors: Buettner U. K. , Davies‐Mostert H. T. , Du Toit J. T. , Mills M. G. L. 
Published: September 2006

AbstractAfrican wild dog Lycaon pictus populations are declining due to persecution as well as habitat destruction and fragmentation. Understanding the natural mechanisms driving population dynamics is important for conservation management as it clarifies natural from human‐induced factors. Therefore, this understanding is essential to compensate for disadvantaging ecological factors and successfully apply conservation actions. Juvenile survival is important in driving wild dog population dynamics, and therefore this study investigated the influence of rainfall and pack size on the survival of juveniles up to the age of 12 months. We found that past rainfall significantly influenced pup survival up to 9 months of age, such that pups benefited from preceding dry periods. The positive effects of pack size on juvenile survival only became evident for pups older than 9 months and, despite this delayed Allee effect, we found no evidence of reproductive failure in small packs as compared with larger ones.
Geophagy and nutrient supplementation in the Ngorongoro Conservation Area, Tanzania, with particular reference to selenium, cobalt and molybdenum
Authors: Mills A. , Milewski A. 
Published: September 2006

AbstractWildlife and livestock in the Ngorongoro Conservation Area (NCA), Tanzania, commonly practise geophagy. We investigated the nutrient content of nine earth licks and adjacent topsoils in the NCA, and for comparative purposes, two salt pans in north‐eastern Tanzania, licks in central Tanzania and a lick near Puerto Maldonado, Peru. The licks had no consistent pattern of nutrient enrichment relative to unutilized topsoils, although the Na content of licks was greater than that of the adjacent topsoils at all but one site. The three largest licks in the NCA (Gibbs Farm, Seneto and Ascent Road) were enriched relative to topsoils and global averages in Se (maximum of 4.7 mg kg−1), Co (maximum of 107 mg kg−1) and/or Mo (maximum of 7.4 mg kg−1). We suggest that licks do provide supplemental Na, but that Se, Co and/or Mo at the largest licks provide easily overlooked nutritional benefits and are perhaps the primary target for geophagy at these sites. Subsoil zones of clay deposition are likely to be enriched in various elements through illuviation or mineral precipitation from solution. Animals may use the taste of NaCl as a clue for locating such zones where they are likely to find a greater quantity of micronutrients relative to other soils. These findings have consequences for conservation and pastoralism in that these large licks may be key resources, providing micronutrients that are essential for maintaining the health and fecundity of animal as well as human populations in the region.
Multicentre, parallel group, randomised, single‐blind study of the safety and efficacy of atosiban versus ritodrine in the treatment of acute preterm labour in Korean women
Authors: Shim J‐Y , Park YW , Yoon BH , Cho YK , Yang J‐H , Lee Y , Kim A 
Published: September 2006

Objective  To compare the efficacy and safety of atosiban with those of ritodrine in preterm labour.Design  Multicentre, single‐blind, randomised, controlled trial.Setting  Obstetric units in six referral centres in Korea.Population  Women with singleton pregnancies with preterm labour, between 24 and 33 + 6 weeks of gestation.Methods  One hundred and twenty‐eight women were randomised to receive intravenous atosiban (n= 63) or ritodrine (n= 65) and were stratified by gestational age (<28 weeks and ≥28 weeks). Atosiban or ritodrine was administered for up to 48 hours. Progression of labour was assessed by the frequency of contractions and cervical dilatation and effacement. Alternative tocolysis could be given as rescue therapy.Main outcome measure  Efficacy was assessed as the proportion of women in each group who did not deliver and did not need alternative tocolytic therapy at 48 hours and 7 days after therapy initiation. Safety was assessed as the numbers of maternal adverse events and neonatal morbidity.Results  Tocolytic efficacy after 7 days was significantly better in the atosiban group than in the ritodrine group (60.3 versus 34.9%), but not at 48 hours (68.3 versus 58.7%). Maternal adverse events related to therapy were reported less frequently in the atosiban group (7.9 vs 70.8%; P= 0.0001), resulting in fewer early drug terminations due to adverse events (0 versus 20.0%; P= 0.0001). This, however, was not accompanied by a concurrent improvement in perinatal outcomes.Conclusion  The efficacy and safety of atosiban in the treatment of preterm labour were superior to those of ritodrine.
A comparison of perinatal mortality in Korea on holidays and working days
Authors: Hong JS , Kang HC , Yi S‐W , Han YJ , Nam CM , Gombojav B , Ohrr H 
Published: September 2006

Objective  To examine whether the perinatal mortality of infants born during holidays differs from that of infants born on workdays, and to elucidate its cause.Design  Cross‐sectional study.Setting  Vital statistics linked to the National Infant Mortality Survey data for 1999 births in Korea.Population  In all, 628 485 births in 1999 in Korea.Methods  Number of births and perinatal mortality were classified according to the day of the week using the occurrence index. After adjusting for confounding factors, the odds ratios (ORs) for increased holiday mortality were estimated using logistic regression.Main outcome measure  Birthweight‐adjusted perinatal mortality.Results  Births on holidays were 33% fewer and perinatal deaths 24% higher than expected (PMR, Perinatal Mortality Rate, 16.4 versus 12.8; OR, 1.3; 95% CI, 1.2–1.4). After the adjustment of birthweight, gender, plurality and congenital anomalies, the odds ratio for death of infants born during holidays was 1.2 (95% CI, 1.1–1.3).Conclusions  The higher perinatal mortality during holidays in Korea appears to be due to different qualities of perinatal care, rather than difference in case‐mix.
Seasonal patterns and preterm birth: a systematic review of the literature and an analysis in a London‐based cohort
Authors: Lee SJ , Steer PJ , Filippi V 
Published: September 2006

Objective  The objectives of this study included a systematic review of the countries in which a seasonal pattern of preterm birth has been reported and an analysis on the seasonal variability of preterm birth in a London‐based cohort.Design  Cross‐sectional study.Setting  Eighteen maternity units in a London health region from 1988 to 2000.Population  The study population comprised 482 765, live singleton births born after 24 weeks of gestation and weighing more than 200 g.Methods  Systematic review and secondary analysis of seasonality over 13 years of births from the St Mary’s Maternity Information System (SMMIS).Main outcome measure  Annual patterns of preterm birth and a comparison of risk by seasons.Results  Three studies from developing countries and three from developed countries reported a seasonal pattern of preterm birth. One study from the USA reported no seasonal pattern of preterm birth. No British studies were located. Rates of preterm birth in developed countries were highest twice a year (once in winter and again in summer). In London (SMMIS data set), however, preterm births peaked only once a year, in winter. Babies born in winter were 10% more likely to be preterm compared with those born in spring (OR 1.10, 95% CI 1.07–1.14).Conclusion  Establishing a seasonal pattern of birth can have important implications for the delivery of healthcare services. Most studies from both developed and developing countries support the existence of preterm birth seasonality. This study has shown that the seasonality of preterm births in this London‐based cohort differs from other developed countries that have previously reported a seasonal pattern of preterm birth.
The effect of learning curve on the outcome of caesarean section
Authors: Fok WY , Chan LYS , Chung TKH 
Published: September 2006

Objective  To evaluate the operative outcomes when trainees first perform caesarean sections independently.Design  A retrospective study in a tertiary obstetric unit.Population  Five hundred caesarean sections, which represented the first 50 caesarean sections performed independently by each of ten trainees, were studied.Methods  The effect of learning curve on outcome was analysed.Main outcome measures  Total operative time, incision‐to‐delivery interval, operative blood loss, Apgar score, cord arterial pH, incidence of neonatal intensive care unit admission, postoperative complication rates and duration of hospitalisation.Results  The mean operative time for the first five cases by trainees was 52.2 ± 11.4 minutes. It progressively decreased and reached 39.6 ± 8.4 minutes for the 46th to 50th cases. The operative time was significantly longer in the first 15 caesarean sections (P < 0.05). Moreover, the incision‐to‐delivery interval was also longer during the first five cases (P= 0.02). Besides the time of the operation, the trend for operative blood loss stabilised after the first ten caesarean sections (P < 0.05). Otherwise, there were no significant differences among other outcome variables.Conclusion  This study shows that trainees need to perform 10–15 caesarean sections before their skills become more proficient. Senior obstetricians may need to provide guidance to the trainees during their first independent 15 caesarean sections.
Prediction of recurrence after treatment for high‐grade cervical intraepithelial neoplasia: the role of human papillomavirus testing and age at conisation
Authors: Verguts J , Bronselaer B , Donders G , Arbyn M , Van Eldere J , Drijkoningen M , Poppe W 
Published: September 2006

Objectives  The aim of this study was to examine the accuracy of the presence of high‐risk human papillomavirus (HR‐HPV) DNA (HR‐HPV DNA test) postconisation as prediction of recurrent or residual cervical intraepithelial neoplasia (CIN) after treatment of high‐grade cervical intraepithelial lesions (CIN2+) in a prospective study and to compare this with follow‐up cytology and the marginal status of the excised tissue.Design  Prospective follow‐up study.Setting  Unselected women presenting at colposcopy clinic of University Hospital Gasthuisberg, Leuven.Population  Seventy‐two women treated with conisation for CIN2 or CIN3.Methods  Women were followed by HR‐HPV DNA test (Hybrid Capture II test of Digene®) every 3 to 6 months. The same vial was used for cytology and the HR‐HPV DNA test (SurePath™). All women were further followed by colposcopy and cytology for 24 months at 6‐month intervals. The outcome of the study was presence of >CIN2, proven with colposcopy‐directed biopsy occurring within 24 months after treatment. HR‐HPV status was correlated with recurrent or residual CIN2+.Main outcome measures  Sensitivity, specificity, predictive values and diagnostic odds ratios to predict treatment failure or cure were computed for HR‐HPV testing, marginal status and follow‐up cytology. HR‐HPV status was also correlated with section margins postconisation and with the first cervical smear.Results  In 6 of the 72 treated women (8%), residual or recurrent CIN occurred. Women with recurrence were significantly older than women without a recurrence (51.5 ± 9.6 versus 39.8 ± 12.2 years, P= 0.007). All six women with recurrence were HR‐HPV positive, four had a positive follow‐up smear (≥atypical squamous cells of uncertain significance = ASCUS+) and only two had involved section margins. Among the 66 cured women, 15 were HR‐HPV positive, 6 had an abnormal smear and 12 had positive section margins. Sensitivity of cytology, positive section margins and HR‐HPV DNA positivity was 66.7, 33.3 and 100% to predict treatment failure. Specificity of the three tests was, respectively, 90.9, 81.8 and 77.3%. Women with HR‐HPV DNA at 3 to 6 months showed recurrent or residual CIN in 15% (2/13) if they had normal follow‐up Pap smears and in 50% (4/8) if they had abnormal Pap smears. Margin status was not statistically significantly associated with human papillomavirus status.Conclusion  Persistence or clearance of HR‐HPV DNA is an early valid prognostic marker of failure or cure after treatment for CIN2+ and is more accurate than cytology or section margin status at the time of conisation. The absence of HR‐HPV DNA has a 100% negative predictive value. Higher age at conisation may be a previously unrecognised risk factor for recurrence.
Polypharmacy and Prescribing Quality in Older People
Authors: Steinman Michael A. , Seth Landefeld C. , Rosenthal Gary E. , Berthenthal Daniel , Sen Saunak , Kaboli Peter J. 
Published: September 2006

OBJECTIVES: To evaluate the relationship between inappropriate prescribing, medication underuse, and the total number of medications used by patients.DESIGN: Cross‐sectional study.SETTING: Veterans Affairs Medical Center.PARTICIPANTS: One hundred ninety‐six outpatients aged 65 and older who were taking five or more medications.MEASUREMENTS: Inappropriate prescribing was assessed using a combination of the Beers drugs‐to‐avoid criteria (2003 update) and subscales of the Medication Appropriateness Index that assess whether a drug is ineffective, not indicated, or unnecessary duplication of therapy. Underuse was assessed using the Assessment of Underutilization of Medications instrument. All vitamins and minerals, topical and herbal medications, and medications taken as needed were excluded from the analyses.RESULTS: Mean age was 74.6, and patients used a mean±standard deviation of 8.1±2.5 medications (range 5–17). Use of one or more inappropriate medications was documented in 128 patients (65%), including 73 (37%) taking a medication in violation of the Beers drugs‐to‐avoid criteria and 112 (57%) taking a medication that was ineffective, not indicated, or duplicative. Medication underuse was observed in 125 patients (64%). Together, inappropriate use and underuse were simultaneously present in 82 patients (42%), whereas 25 (13%) had neither inappropriate use nor underuse. When assessed by the total number of medications taken, the frequency of inappropriate medication use rose sharply from a mean of 0.4 inappropriate medications in patients taking five to six drugs, to 1.1 inappropriate medications in patients taking seven to nine drugs, to 1.9 inappropriate medications in patients taking 10 or more drugs (P<.001). In contrast, the frequency of underuse averaged 1.0 underused medications per patient and did not vary with the total number of medications taken (P=.26). Overall, patients using fewer than eight medications were more likely to be missing a potentially beneficial drug than to be taking a medication considered inappropriate.CONCLUSION: Inappropriate medication use and underuse were common in older people taking five or more medications, with both simultaneously present in more than 40% of patients. Inappropriate medication use is most frequent in patients taking many medications, but underuse is also common and merits attention regardless of the total number of medications taken.
The Epidemiology of Bathing Disability in Older Persons
Authors: Gill Thomas M. , Guo Zhenchao , Allore Heather G. 
Published: September 2006

OBJECTIVES: To quantify the burden of bathing disability over time; to determine whether the burden of bathing disability differs according to age, sex, and physical frailty; and to evaluate the relationship between disability in bathing and disability in other essential activities of daily living (ADLs).DESIGN: Prospective cohort study.SETTING: General community in greater New Haven, Connecticut.PARTICIPANTS: Seven hundred fifty‐four community‐living older persons aged 70 and older who were nondisabled (required no personal assistance) in four essential ADLs: bathing, dressing, transferring from a chair, and walking inside the house.MEASUREMENTS: Bathing disability, defined as the inability to wash and dry one's whole body without personal assistance, was assessed every month for up to 6 years, along with disability in dressing, transferring, and walking.RESULTS: Over the course of 6 years, 440 participants (58.4%) had at least one episode of bathing disability, and 266 (34.0%) had multiple episodes, with the duration of each episode averaging about 6 months. Whether assessed as number of episodes, duration of episodes, incidence rates, or number of months per 100 months, the burden of bathing disability was greatest in participants who were physically frail and was consistently higher in women than men and in participants who were aged 80 and older than those who were aged 70 to 79. Most episodes of bathing disability (86.1%) were not preceded in the prior month by disability in dressing, transferring, or walking, and nearly half (48.3%) were not accompanied at onset by disability in one or more of these other ADLs. In a multivariable model that included age, sex, and physical frailty, the onset of bathing disability increased the likelihood of developing disability in the other essential ADLs the following month fivefold (hazard ratio=5.1, 95% confidence interval=4.1–6.4).CONCLUSION: Disability in bathing may serve as a sentinel event in the disabling process. Given the recurrent nature of bathing disability, programs designed to enhance independent bathing will need to focus not only on the prevention of bathing disability, but also on the restoration and maintenance of independent bathing in older persons who become disabled.
Diagnosis and Characteristics of Syncope in Older Patients Referred to Geriatric Departments
Authors: Ungar Andrea , Mussi Chiara , Del Rosso Attilio , Noro Gabriele , Abete Pasquale , Ghirelli Loredana , Cellai Tommaso , Landi Annalisa , Salvioli Gianfranco , Rengo Franco , Marchionni Niccolò , Masotti Giulio ,   for the Italian Group for the Study of Syncope in the Elderly
Published: September 2006

OBJECTIVES: To test the applicability and safety of a standardized diagnostic algorithm in geriatric departments and to define the prevalence of different causes of syncope in older patients.DESIGN: Multicenter cross‐sectional observational study.SETTING: In‐hospital geriatric acute care departments and outpatient clinics.PARTICIPANTS: Two hundred forty‐two patients (aged ≥65, mean±standard deviation =79±7, range 65–98) consecutively referred for evaluation of transient loss of consciousness to any of six clinical centers participating in the study. Of these, 11 had a syncope‐like condition (5 transient ischemic attack; 6 seizures), and 231 had syncope (aged 65–74, n=71; aged ≥75, n=160).MEASUREMENTS: Protocol designed to define etiology and clinical characteristics of syncope derived from European Society of Cardiology Guidelines on syncope.RESULTS: No major complication occurred with use of the protocol. Neurally mediated was the more prevalent form of syncope in this population (66.6%). Cardiac causes accounted for 14.7% of all cases. The neuroreflex form of syncope (vasovagal, situational, and carotid sinus syndrome) was more common in younger than in older patients (62.3% vs 36.2%; P=.001), whereas orthostatic syncope was more frequent in the older than in the younger group (30.5% vs 4.2%; P<.001). In only 10.4% of cases, syncope remained of unexplained origin. After initial evaluation, a definite diagnosis was possible in 40.1% of the cases, and a suspected diagnosis was obtained in 57.9%. Syncope of suspected cardiac origin after initial evaluation was confirmed in 43.7% of cases, and neuromediated causes were confirmed in 83.5% of the cases.CONCLUSION: The protocol is applicable even beyond the age of 90 in geriatric departments. The standardized protocol is associated with a reduction in the frequency of unexplained syncope to about 10%.