bluuebunny/crossref_metadata_2025_split huggingface dataset:
Robust Linear Clustering
Authors: García-Escudero L. A. , Gordaliza A. , San Martín R. , Van Aelst S. , Zamar R. 
Published: October 2008

SummaryNon-hierarchical clustering methods are frequently based on the idea of forming groups around ‘objects’. The main exponent of this class of methods is the k-means method, where these objects are points. However, clusters in a data set may often be due to certain relationships between the measured variables. For instance, we can find linear structures such as straight lines and planes, around which the observations are grouped in a natural way. These structures are not well represented by points. We present a method that searches for linear groups in the presence of outliers. The method is based on the idea of impartial trimming. We search for the ‘best’ subsample containing a proportion 1−α of the data and the best k affine subspaces fitting to those non-discarded observations by measuring discrepancies through orthogonal distances. The population version of the sample problem is also considered. We prove the existence of solutions for the sample and population problems together with their consistency. A feasible algorithm for solving the sample problem is described as well. Finally, some examples showing how the method proposed works in practice are provided.
Cellular localization of GDNF and its GFRalpha1/RET receptor complex in the developing pancreas of cat
Authors: Lucini C. , Maruccio L. , Facello B. , Cocchia N. , Tortora G. , Castaldo L. 
Published: October 2008

AbstractGlial cell line‐derived neurotrophic factor (GDNF) acts through RET receptor tyrosine kinase and its co‐receptor GFRalpha1. In an effort to better understand the possible biological contribution of the GDNF and GFRalpha1/RET complex in pancreatic development, in this study we report the cellular localization of these proteins in the pancreas of domestic cat embryos and fetuses by immunocytochemical methods. In early embryos, GDNF, GFRalpha and RET immunoreactivity (IR) was localized in closely intermingled cells. GDNF and RET immunoreactive cells displayed chromogranin (an endocrine marker) and PGP 9.5 (a neuronal marker) IR, respectively. GFRalpha IR was present in both a few GDNF/chromogranin and RET/PGP 9.5 immunoreactive cells. In elderly fetuses, GDNF and GFRalpha IR were co‐localized in glucagon cells and RET IR was detected in few neurons and never co‐localized with GFRalpha or GDNF IR. In early embryos, the presence of GDNF IR in chromogranin immunoreactive cells and GFRalpha1/RET complex IR in PGP9.5 immunoreactive cells seems to suggest a paracrine action of GDNF contained in endocrine cell precursors on neuronal cell precursors expressing its receptor complex. The presence in different cell populations of RET and its co‐receptor GFRalpha1 IR could be due to independent signaling of GRFalpha1. Thus, the co‐presence of GDNF and GFRalpha1 in chromogranin and glucagon cells could lead to the hypothesis that GDNF can act in an autocrinal manner. In fetuses, RET IR was detected only in intrapancreatic ganglia. Because of the lack of GFRalpha1 IR in pancreatic innervation, RET receptor could be activated by other GFR alphas and ligands of GDNF family. In conclusion, these findings suggest that in differently aged embryos and fetuses the GDNF signal is differently mediated by RET and GFRalpha1.
Combined finite element and multibody dynamics analysis of biting in a Uromastyx hardwickii lizard skull
Authors: Moazen M. , Curtis N. , Evans S. E. , O’Higgins P. , Fagan M. J. 
Published: October 2008

AbstractLizard skulls vary greatly in shape and construction, and radical changes in skull form during evolution have made this an intriguing subject of research. The mechanics of feeding have surely been affected by this change in skull form, but whether this is the driving force behind the change is the underlying question that we are aiming to address in a programme of research. Here we have implemented a combined finite element analysis (FEA) and multibody dynamics analysis (MDA) to assess skull biomechanics during biting. A skull of Uromastyx hardwickii was assessed in the present study, where loading data (such as muscle force, bite force and joint reaction) for a biting cycle were obtained from an MDA and applied to load a finite element model. Fifty load steps corresponding to bilateral biting towards the front, middle and back of the dentition were implemented. Our results show the importance of performing MDA as a preliminary step to FEA, and provide an insight into the variation of stress during biting. Our findings show that higher stress occurs in regions where cranial sutures are located in functioning skulls, and as such support the hypothesis that sutures may play a pivotal role in relieving stress and producing a more uniform pattern of stress distribution across the skull. Additionally, we demonstrate how varying bite point affects stress distributions and relate stress distributions to the evolution of metakinesis in the amniote skull.
The effect of cAMP signaling on the longitudinal extension of spinal sensory neurons in the chicken embryo
Authors: Coutinho‐Budd Jaeda C. , Ezerman Elizabeth B. , Forehand Cynthia J. 
Published: October 2008

AbstractDeveloping sensory axons grow into the spinal cord in a three‐step process: the axons extend toward and into the cord, then branch rostrally and caudally to establish a longitudinal pathway, and finally grow into the grey matter. This study investigated regulation by cAMP of the longitudinal extension of this pathway within the spinal cord. The cAMP pathway was pharmacologically altered in chicken embryos to determine its effects on the establishment of the longitudinal extension of the dorsal funiculus. A forskolin‐induced increase in cAMP in ovo inhibited longitudinal growth by sensory afferents. Furthermore, blocking cAMP activation of protein kinase A (PKA) in ovo with H‐89 substantially increased longitudinal extension. These results demonstrate a specific role for the cAMP/PKA pathway in the initial longitudinal spinal afferent growth in the chicken embryo.
The parent–nurse relationship in the neonatal intensive care unit context – closeness and emotional involvement
Authors: Fegran Liv , Helseth Sølvi 
Published: October 2008

Aim and background:  Family‐centred care, which acknowledges parents as partners in care, is a desirable and essential part of neonatal nursing. There has been extensive research on parents’ experiences of parenting in neonatal intensive care units (NICU), but there is little research on nurses’ experiences of being in these enduring close relationships. The aim of this paper is to explore parents’ and nurses’ experiences of the close parent–nurse relationship when a premature child is hospitalized.Method:  The design was exploratory with a hermeneutic approach. The methods used were participant observation and in‐depth interviews with six mothers, six fathers and six nurses in a Norwegian 13‐bed NICU. Eighteen individual interviews and 160 hours of observations were conducted over 27 weeks from 2003 to 2004. This study complies with the principles of the Declaration of Helsinki. The Regional Committee for Medical Research Ethics, the Ombudsman for Privacy in Research at the Norwegian Social Science Data Services and the hospital’s research department approved the study protocol.Results:  The NICU context is a technological environment where human interaction is a crucial issue. The character of the context and the ongoing interactions drive parents and nurses into close relationships. Closeness increases the emotional involvement and the boundary between the professional and the personal approach is threatened. The commitment of being close, combined with the emotional involvement, can be an emotional burden to both parents and nurses.Conclusion:  Parent–nurse closeness in NICU is desirable; however, the emotional burden of this closeness seems to be seldom problematized. Awareness about the need to strike a balance between closeness and distance can positively influence parents’ independence and nurses’ ability to maintain professional relationships with their primary care parents.
Male sex and pre‐existing diabetes are independent risk factors for stillbirth
Authors: ENGEL Patricia J. , SMITH Roger , BRINSMEAD Maxwell W. , BOWE Stephen J. , CLIFTON Vicki L. 
Published: October 2008

AbstractAim:  To determine whether the risk of stillbirth is associated with male fetal sex, fetal growth and maternal factors in an Australian population.Methods:  A retrospective secondary data analysis of 16 445 singleton births was performed using a tertiary referral centre obstetric database (1995–1999). Univariate and multiple logistic regression analyses were performed.Results:  Stillbirth complicated 1% of the pregnancies in the study population, and 59% of stillbirths were associated with a male fetus. Significant characteristics associated with stillbirth were intrauterine growth restriction (IUGR), birth defects, gestational age, Aboriginal ethnicity, previous stillbirth, parity greater than three and placental abruption. Male stillbirths were more likely to occur at a later gestation (median gestation 30.5 weeks, range 20–43 weeks) compared to females (median 25 weeks, range 20–40 weeks), P = 0.01. Sixty per cent of IUGR fetuses were female (P < 0.001). Male sex (odds ratio (OR) 1.5, confidence interval (CI) 1.01, 2.17, P = 0.04) and maternal type 1 diabetes (OR 4.7, CI 1.58, 14.19, P = 0.006) were independently associated with stillbirth.Conclusion:  Male fetal sex and pre‐existing diabetes are independent risk factors for stillbirth. Diabetes remains a significant risk for stillbirth even with contemporary monitoring and clinical management. Those diabetic pregnancies where the fetus is male require appropriate monitoring and timely interventions to achieve an optimal outcome.
Use of complementary and alternative medicines by a sample of Australian women during pregnancy
Authors: SKOUTERIS Helen , WERTHEIM Eleanor H. , RALLIS Sofia , PAXTON Susan J. , KELLY Leanne , MILGROM Jeannette 
Published: October 2008

Background: The use of complementary and alternative medicines (CAM) is growing in Australia, with women higher users than men. Yet, only a few Australian studies have explored the use of CAM during pregnancy.Aims: To explore the use of CAM, the types of CAM practitioners consulted, physical symptoms/complaints for which CAM are used by a sample of pregnant Australian women, and women's perceptions of the efficacy of CAM in treating those complaints.Methods: Three hundred and twenty‐one pregnant women, who volunteered for a study exploring women's well‐being during pregnancy, completed a self‐report questionnaire in their late second/early third trimester.Results: Seventy‐three per cent of women had used at least one kind of complementary therapy in the prior eight weeks of pregnancy. Over one‐third of the women had visited at least one alternative medicine practitioner during pregnancy. Approximately one‐third of the women reported taking CAM to alleviate a specific physical symptom, with 95.7% of these women reporting they either got completely better or a little bit better with use of CAM; one quarter reported planning to use an alternative therapy to assist with labour preparation. Age, number of physical symptoms experienced, income level and level of education were not associated with greater use of CAM (P < 0.05); however, women reporting more physical symptoms were more likely to consult a CAM practitioner.Conclusion: Findings highlight the substantial use of CAM during pregnancy and the need to have all health professionals adequately informed about such therapies during this life stage.
Elective caesarean delivery at maternal request: A preliminary study of motivations influencing women's decision‐making
Authors: ROBSON Stephen , CAREY Alexandra , MISHRA Rasmita , DEAR Keith 
Published: October 2008

Background:  There is an extensive literature concerning caesarean section at maternal request, where no obstetric indication exists, yet little information about what motivates women to request such a delivery.Aims:  This paper aims to ask women who had undergone maternal‐request primary elective caesarean delivery about the reasons for their choice, their level of satisfaction with the delivery and their future childbearing plans.Methods:  Anonymous postal survey of women who have undergone maternal‐request primary caesarean section in private maternity hospitals in the eastern states of Australia.Results:  The response rate was 68%, and 78 completed surveys were included in the study. The most common reason given was, ‘I was concerned about risks to the baby’ (46%). On a scale from 1 (totally unsatisfied) to 10 (completely satisfied), the mean satisfaction rating reported was 9.25/10 (95% confidence interval: 8.89, 9.60). Only eight respondents (10%) stated an intention for more than two caesarean deliveries.Conclusions:  Women who underwent maternal‐request caesarean delivery most commonly did so from concerns for the baby. Respondents were highly satisfied with their delivery, and few wished for more than two children.
Secondary school students’ knowledge, attitudes, and practice toward epilepsy in the Batibo Health District—Cameroon
Authors: Njamnshi Alfred K. , Angwafor Samuel A. , Jallon Pierre , Muna Walinjom F. T. 
Published: October 2008

SummaryUsing a 12‐item questionnaire, we assessed knowledge, attitudes, and practice (KAP) toward epilepsy and identified determinants of inappropriate attitudes toward people with epilepsy (PWE) among 910 randomly selected secondary school students in Batibo (Cameroon). Ninety‐five percent of the students had heard or read about epilepsy, 73.3% knew an epileptic, and 76.4% had witnessed a seizure. Those who would offer equal employment opportunities to PWE, refuse to associate with, or refuse to marry PWE represented 58.6%, 25.4%, and 64.2%, respectively. Negative attitudes appeared to be reinforced by beliefs that epilepsy is hereditary (25.7%), contagious (49.9%), or a kind of insanity (38%). Acquaintance with PWE tended to improve the misconception that epilepsy is contagious (p < 0.001), and to reinforce the view that it is a form of insanity (p < 0.01). A successful epilepsy education program must account for local beliefs, and secondary school students may constitute a good channel for community education.
Single injection of a low dose of pentylenetetrazole leads to epileptogenesis in an animal model of cortical dysplasia
Authors: Oghlakian Roger O. , Tilelli Cristiane Q. , Hiremath Girish K. , Alexopoulos Andreas V. , Najm Imad M. 
Published: October 2008

SummaryPurpose: Cortical dysplasia (CD) is one of the most frequent causes of pharmacoresistent focal epilepsy. Despite significant advances in various diagnostic and therapeutic methods, the basic mechanisms of higher susceptibility for seizures in patients with CD are unknown. Animal models of CD present with a lower threshold for seizure induction. The purpose of this study is to further characterize the animal model of in utero radiation‐induced CD and to illustrate the effect of a late postnatal second hit (low dose of pentylenetetrazole, PTZ) on the development of spontaneous seizures.Methods: Pregnant Sprague–Dawley rats were irradiated on E17 (145 cGy; control group was left untreated). Litters were implanted with bifrontal epidural and hippocampal depth electrodes. After baseline electroencephalography (EEG) recording, animals received 30 mg/kg PTZ and were chronically monitored. Histopathology of the brains was verified.Results: No seizures were detected in animals that did not receive PTZ. PTZ‐injected irradiated (XRT) rats showed severe prolonged, repetitive seizures during the acute period. During the chronic period, XRT rats had recurrent seizures and epileptiform spikes. PTZ‐injected control animals exhibited milder and fewer acute seizures and did not show seizures during the chronic period. Histology was consistent with cortical and hippocampal dysplasia.Conclusions: This study shows that a single treatment with a low dose of PTZ renders XRT rats (but not age‐matched controls) epileptic, exhibiting spontaneous epileptiform spikes and seizures on EEG. These results might mirror the natural history of patients with CD thought to be caused by prenatal/congenital or perinatal insults.
Prevalence of ALDH7A1 mutations in 18 North American pyridoxine‐dependent seizure (PDS) patients
Authors: Bennett Craig L. , Chen Yingzhang , Hahn Sihoun , Glass Ian A. , Gospe Jr Sidney M. 
Published: October 2008

SummaryPurpose:  Pyridoxine‐dependent seizure (PDS) is a rare disorder characterized by seizures that are resistant to common anticonvulsants, and that are ultimately controlled by daily pharmacologic doses of pyridoxine (vitamin B6). Mutations of the antiquitin gene (ALDH7A1) are now recognized as the molecular basis of cases of neonatal‐onset PDS.Methods:  Bidirectional DNA sequence analysis of ALDH7A1 was undertaken along with plasma pipecolic acid (PA) measurements to determine the prevalence of ALDH7A1 mutations in a cohort of 18 North American patients with PDS.Results:  In patients with neonatal‐onset PDS, compound heterozygous or homozygous ALDH7A1 mutations were detected in 10 of 12 cases, and a single mutation was found in the remaining 2. In later‐onset cases, mutations in ALDH7A1 were detected in three of six cases. In two patients with infantile spasms responsive to pyridoxine treatment and with good clinical outcomes, no mutations were found and PA levels were normal. In total, 13 novel mutations were identified.Discussion:  Our study advances previous findings that defects of ALDH7A1 are almost always the cause of neonatal‐onset PDS and that defects in this gene are also responsible for some but not all later‐onset cases. Later‐onset cases of infantile spasms with good outcomes lacked evidence for antiquitin dysfunction, suggesting that this phenotype is less compelling for PDS.
Accuracy of Impression Techniques for Implants. Part 1 – Influence of Transfer Copings Surface Abrasion
Authors: Assunção Wirley Gonçalves , Cardoso Alessandra , Gomes Erica Alves , Tabata Lucas Fernando , Santos Paulo Henrique dos 
Published: October 2008

Abstract Purpose: This study evaluated the influence of surface abrasion of transfer copings to obtain a precise master cast for a partially edentulous restoration with different inclinations. Materials and Methods: Replicas (N = 30) of a metal matrix (control group) containing two implants at 90° and 65° in relation to the benchtop were obtained using a polyether impression material and three impression techniques: square impression copings splint with dental floss and autopolymerizing acrylic resin (TRS), square impression copings abraded with aluminum oxide (TA), and square impression copings abraded with aluminum oxide and adhesive‐coated (TAA). The replicas obtained in type V stone were digitalized, and the images were exported to AutoCAD software to perform the readings of possible degree alterations in implant inclinations. The results were submitted to analysis of variance (ANOVA) and Tukey test (α < 0.05). Results: Comparing the techniques with regard to the 90° implant inclination, no statistical difference was observed between the three techniques and the control group. Analyzing the three techniques with regard to the 65° implant inclination, no significant difference was seen between technique TA and the control group. Conclusions: Technique TA presented more accurate master casts than TRS and TAA techniques. The angulated implant (65°) tended to generate more imprecise master casts than implants perpendicular to the surface.
Shade‐Matching Abilities of Dental Laboratory Technicians Using a Commercial Light Source
Authors: Jasinevicius T. Roma , Curd Francis M. , Schilling Lindsey , Sadan Avishai 
Published: October 2008

Abstract Purpose: The purpose of this study was to evaluate dental laboratory technicians' abilities to match shades using a light‐corrective device under conventional laboratory conditions. The variables measured were years experience, gender, and light source. Materials and Methods: A 14‐item shade‐matching quiz (SMQ) was field‐tested and deemed adequate. Information included age, gender, number of years experience, and Ishihara's Colour‐Blindness Assessment. Forty‐two dental technicians from five northeast Ohio laboratories were invited to participate. The SMQ was administered twice: under the lighting conditions in the individual laboratories (SMQ‐Lab) and with a light‐corrective source (SMQ‐LC). For each item, the technicians were to select the matching Vita shade tab from five preselected shade tabs. SMQ scores equaled the number of correct matches. Statistical analysis included calculation of means, standard deviations, correlation coefficients, and independent and paired t‐tests. Significance was set at p≤ 0.05. Results: Twenty male and 20 female technicians participated. None were color‐deficient. The SMQ scores were significantly higher with the light‐corrective device than under laboratory lighting: 12.0 ± 1.9 and 10.0 ± 2.0, respectively (p < 0.001). There were no significant correlations between years experience and SMQ scores, nor were there differences between scores by gender. In general, the Vita C shades were least likely to be matched. Conclusions: Within the limitations of this study, dental technicians' shade‐matching abilities were better with a light‐corrective device than under the conventional laboratory lighting conditions. Gender and experience were not factors in matching shades. The Vita C shades were least likely to be matched.
Comparison of Marginal Fit between All‐Porcelain Margin versus Alumina‐Supported Margin on Procera® Alumina Crowns
Authors: Limkangwalmongkol Penwadee , Kee Edwin , Chiche Gerard J. , Blatz Markus B. 
Published: October 2008

Abstract Purpose: Procera® Alumina crowns are widely used; however, the effect of crown margin design on marginal fit is unknown. This study measured and compared the precision of fit of Procera® Alumina crowns with two crown margin designs: all‐porcelain versus alumina‐supported margins. Materials and Methods: Sixteen noncarious extracted human premolars were prepared for Procera® Alumina crowns with an internally rounded shoulder preparation. Impressions were made from all teeth, and master dies were poured with type IV dental stone. The specimens were randomly divided into two groups. Procera® Alumina crowns were fabricated: eight crowns with circumferential porcelain‐butt (all‐porcelain) margins and eight crowns with coping (alumina‐supported) margins (control). Precision of fit was measured at six points on each crown with a profilometer (profile projector). The data were statistically analyzed with an independent‐samples t‐test (α < 0.05). Results: The mean marginal gap size (μm) of coping margins was 68.07 ± 16.08 and of porcelain‐butt margins was 101.29 ± 43.71. There was no statistically significant difference (p= 0.065) of the marginal gap size between coping margins and porcelain‐butt margins. Conclusion: The results of this study demonstrate that there was no statistically significant difference in the marginal fit of coping and porcelain‐butt margins. Both margin designs are within clinically acceptable ranges. Therefore, clinicians may choose to use a coping margin, as it is less labor intensive and requires less time for fabrication, unless there is a specific high esthetic need for a porcelain‐butt margin.