bluuebunny/crossref_metadata_2025 huggingface dataset:
A detailed proteomic profiling of plasma membrane from zebrafish brain
Authors: Smidak Roman , Aradska Jana , Kirchberger Stefanie , Distel Martin , Sialana Fernando J. , Wackerlig Judith , Mechtcheriakova Diana , Lubec Gert
Published: July 2016

Zebrafish (Danio rerio) is a well‐established model organism in developmental biology and disease modeling. In recent years, an increasing amount of studies used zebrafish to analyze the genetic changes underlying various neurological disorders. The brain plasma membrane proteome represents the major subsets of signaling proteins and promising drug targets, but is often understudied due to traditional experimental difficulties including problems with solubility, detergent removal, or low abundance. Here, we report a comprehensive dataset of the proteins identified in the enriched plasma membrane of the zebrafish brain by applying sequential trypsin/chymotrypsin digestion with multidimensional LC‐MS/MS. A total number of 97 017 peptide groups corresponding to 9201 proteins were identified. These were annotated in various molecular functions or neurological disorders. The dataset of the current study provides a useful data source for further utilizing zebrafish in basic and clinical neuroscience.
Interactions of hydrogen with vanadium in crystalline silicon
Authors: Mullins Jack , Markevich Vladimir P. , Halsall Matthew P. , Peaker Anthony R.
Published: July 2016

In this work, we have investigated interactions of vanadium with hydrogen in n‐ and p‐type float zone grown silicon using deep level transient spectroscopy (DLTS), Laplace DLTS, capacitance‐voltage and secondary ion mass spectroscopy measurements (SIMS). Vanadium was introduced into Si wafers by ion implantation with subsequent heat treatments at 800 °C for removing the implantation induced lattice damage. In the DLTS spectra of the annealed samples, we have observed two deep level states due to interstitial vanadium (Vi) atoms in n‐type Si and one in p‐type Si. A comparison of concentration profiles of the Vi atoms with those for the total concentration of V measured by SIMS has shown that at the projected implantation depth the [Vi]/[Vtotal] ratio is less than 0.05 at chemical concentration of vanadium of 1 × 1015 cm−3, so the majority of V atoms are in electrically inactive states in this region. At lower chemical concentrations of vanadium, similar values of [Vi] and [Vtotal] are observed. After the treatment of the n‐type V‐doped samples in a remote hydrogen plasma at room temperature, we have found that the concentration of the Vi atoms decreases while additional electron traps emerge in the DLTS spectra. A trap with the highest concentration has been attributed to a vanadium–hydrogen complex. In the p‐type Si:V samples, no new levels have emerged in the DLTS spectra after the H‐plasma treatments. It is suggested that in p‐type Si:V an interaction of H atoms with the Vi atoms is suppressed because of the Coulombic repulsion of positively charged Vi and hydrogen defects. It is argued that no electrically active defects are formed in either the n‐ or p‐type Si:V samples due to possible interactions of hydrogen with electrically inactive V‐related defects. We present evidence that annealing of the n‐type Si:V samples in the temperature range 75–125 °C following the application of hydrogen plasma results in up to 20% decrease in the total concentration of electrically active V‐related defects, indicating the formation of some electrically inactive V–H complexes. Heat treatments at temperatures above 175 °C have resulted in the disappearance of all the V–H complexes and recovery of electrical activity of the Vi atoms.
Abundance of field‐ionized ion species and current stability of ion beam emitted in He–Ne gas mixture
Authors: Komaki Keisuke , Nagai Shigekazu , Iwata Tatsuo , Kajiwara Kazuo , Hata Koichi
Published: July 2016

An attempt to increase the He ion current of a gas field ion source is made using a He–Ne mixture. The abundance of each ion in the produced ion beam is examined as a function of the applied field, along with the composition of the supplied gas mixture, using a field ion microscope equipped with a time‐of‐flight mass spectrometer. The operating conditions under which the He ion current is enhanced and no Ne ions are detected are confirmed. For the conditions under which He and Ne ions are detected simultaneously, a spike‐like current change showing the positive correlation between each ion current is observed. Copyright © 2016 John Wiley & Sons, Ltd.
Effect of Cu in electroless Ni–Cu–P coating on passivation process
Authors: Gan Yiwei , Zhao Tingting , Kang Zhixin , Sang Jing
Published: July 2016

Electroless Ni–P and Ni–Cu–P coatings were passivated by chromate conversion treatment respectively. The anticorrosive performances of passivated coatings were investigated by potentiodynamic polarization and electrochemical impedance spectroscopy measurements. The passivated Ni–Cu–P coating exhibited a high corrosion resistance with the icorr of 0.236 μA/cm,2 while the value of passivated Ni–P coating was only 1.030 μA/cm,2 indicating the passive film could improve the corrosion resistance of Ni–Cu–P coating to a significant extent. High‐resolution X‐ray photoelectron spectroscopy was used to determine the chemical states of elements detected in the passive film. Compared with passivated Ni–P coating, the passive film on Ni–Cu–P coating exhibited a higher ratio of Cr2O3 to Cr(OH)3 with the value of 72:28, which was the main factor for passivated Ni–Cu–P coating showing excellent corrosion resistance. The effect of Cu in electroless Ni–Cu–P coating on passivation process was discussed by the contrast experiment. Copyright © 2016 John Wiley & Sons, Ltd.
Immobilization of Cryptococcus flavus α‐amylase on glass tubes and its application in starch hydrolysis
Authors: Pereira Sueli Essado , Fernandes Kátia Flávia , Ulhoa Cirano José
Published: July 2016

α‐Amylase from Cryptococcus flavus was previously purified after exchange chromatography on Q‐Sepharose and gel filtration on Sephacryl S‐100. The enzyme was purified 128‐fold with a recovery rate of 81% of activity. The molecular mass of the α‐amylase was 67 kDa as determined by SDS–PAGE. The enzyme was characterized after immobilization on glass tubes. The immobilization yield, efficiency, and activity recovery of α‐amylase were 79, 57, and 45%, respectively. The optimum pH of the immobilized enzyme was shifted to a more acidic pH (4.5) compared with the free enzyme (5.5). The optimum temperature of the immobilized enzyme was the same for the free enzyme (50°C), but it showed a higher thermal stability. The immobilized enzyme showed activity until the 10th cycle, maintaining 47% of initial activity, and was capable of hydrolyzing starch from potato, wheat, corn, and cassava. The main products released from starch were maltose, maltotriose, and maltotetraose.
The Role of Emotions for the Perceived Usefulness in Online Customer Reviews
Authors: Felbermayr Armin , Nanopoulos Alexandros
Published: July 2016

Online customer reviews often express emotions. This can enable marketers to analyze the textual content of online reviews with the aim to understand the role of emotions and how they can affect other customers. In this paper, we present an approach to extracting emotion content from online reviews in order to measure the importance of various emotion dimensions within different product categories. The approach uses an emotion lexicon to extract emotion terms, while it also builds a classification model to measure the importance of emotion dimensions based on the quality of reviews. Review quality is measured based on the usefulness of online customer reviews, which are perceived and evaluated by other customers through their helpfulness ratings. This approach allows the identification of emotion dimensions that characterize qualitative reviews. The empirical evaluation in our study suggests that trust, joy, and anticipation are the most decisive emotion dimensions, although substantial variance across product categories can also be detected. Additionally, we compared two contrasting emotion dictionaries. One lexicon was crowd-funded and contained a large vocabulary, whereas the other was more focused and smaller, since it was created word-wise by an expert. Our empirical findings indicate that the crowd-funded solution outperforms its smaller counterpart in terms of classification precision. The main implication of this study is that it adds an emotional perspective to the broad set of existing tools that marketers employ to analyzing online reviews. Our contributions are: i) we are the first to analyze emotions’ role in online customer reviews; ii) we demonstrate how to develop a big data model such as this, without external assistance; iii) we show how to interpret the results of the created model; and iv) we show which dictionary to prefer when creating the model.
Models and metrics to assess humanitarian response capacity
Authors: Acimovic Jason , Goentzel Jarrod
Published: July 2016

The race to meet vital needs following sudden onset disasters leads response organizations to establish stockpiles of inventory that can be deployed immediately. These government or non‐government organizations dynamically make stockpile decisions independently. Even though the value of one organization's stock deployment is contingent on others' decisions, decision makers lack evidence regarding sector capacity to assess the marginal contribution (positive or negative) of their action. To our knowledge, there exist no metrics describing the system capacity across many agents to respond to disasters. To address this gap, our analytical approach yields new humanitarian logistics metrics based on stochastic optimization models. Our study incorporates empirical data on inventory stored by various organizations in United Nations facilities and in their own warehouses to offer practical insights regarding the current humanitarian response capabilities and strategies. By repositioning inventory already deployed, the system could respond to disasters in the same expected time with a range of 7.4%–20.0% lower cost for the items in our sample.
Analgesia for acute gingivostomatitis: a national survey of pediatric emergency physicians
Authors: MacLellan Joe , Ali Samina , Curtis Sarah , Baserman Jason , Dixon Andrew
Published: July 2016

Objectives

Gingivostomatitis is a common, painful pediatric presentation, and yet, few studies are available to guide management. We aimed to describe pediatric emergency physicians’ current practice patterns, with respect to analgesic use in children with acute gingivostomatitis, in order to inform future studies.

Methods

A national survey was conducted at all 15 national academic pediatric centres.

Electronic surveys were distributed to pediatric emergency physicians using a modified Dillman protocol; non-respondents received paper surveys via post. Data were collected regarding demographic characteristics, clinical behaviour, factors that may influence practice, and future directions.

Results

Response rate was 74% (150/202). Most physicians (72%) preferred the combination of acetaminophen and ibuprofen to either agent alone (ibuprofen 19%, acetaminophen 7%). The preferred second-line analgesics were oral morphine (48%, 72/150) and compounded topical formulas (42%, 64/150). The most commonly cited compounded agent was Benadryl plus Maalox (23%, 35/150). Clinical experience with a medication had the greatest influence on practice pattern, with 52% (78/149) strongly agreeing. The most commonly cited barrier to adequate analgesia was difficulty in the administration of topical or oral medication to children.

Conclusions

As with many other painful conditions, the combination of acetaminophen and ibuprofen was preferred, followed by either agent alone. Oral morphine and topical compounded agents were also frequently prescribed. Regardless of patient age, physicians preferred oral morphine as a second-line agent to treat pain from severe gingivostomatitis. Future research will focus on determining which analgesic and route (oral or topical) is the most effective and best-tolerated choice.
Disaster Preparedness Among Older Japanese Adults With Long-Term Care Needs and Their Family Caregivers
Authors: Wakui Tomoko , Agree Emily M. , Saito Tami , Kai Ichiro
Published: July 2016

Objective

In the 2011 Great East Japan Earthquake, as in Hurricanes Katrina and Rita in the United States, older individuals were at the greatest risk of mortality. Much concern has been raised about developing plans to reduce these risks, but little information has been provided about preparedness, and the key role played by caregivers has been largely unexplored. The aims of this study were thus to examine the preparedness of family caregivers of older adults with long-term care needs and to identify the characteristics of older adults and their caregivers that are associated with poor preparedness and greater concern about disasters.

Methods

Shortly after the Great East Japan Earthquake, the second wave of the Fukui Longitudinal Caregiver Study was administered to the family caregivers of older Japanese individuals with long-term care needs. The sample included 952 caregivers from 17 municipalities in Fukui prefecture. Logistic regression analyses were used to identify the factors associated with self-assessed preparedness, evacuation planning, and caregivers’ concerns about preparedness.

Results

The majority (75%) of the caregivers had no concrete plans for evacuation in an emergency, and those caring for persons with dementia were 36% less likely to have any plan. In multivariate models, caregivers who were more experienced and wealthier and who reported more family and community support were more likely to feel well prepared. Caregivers with poor health or limited financial resources or who were responsible for older persons with mobility difficulties reported higher levels of anxiety about their disaster preparedness.

Conclusions

This study indicates that most caregivers are ill prepared to respond in emergencies and that caregiver resources, community support, and the needs of older care recipients influence both preparedness and concern about disasters. Education for caregivers and the development of community support programs could provide important sources of assistance to this vulnerable group. (Disaster Med Public Health Preparedness. 2017;11:31–38)
Spectroscopic Pulsational Frequency and Mode Determination of the γ Doradus Star HD 189631
Authors: Davie M. W. , Pollard K. R. , Cottrell P. L. , Brunsden E. , Wright D. J. , De Cat P.
Published: July 2016

We present improvement and confirmation of identified frequencies and pulsation modes for the γ Doradus star HD 189631. This work improves upon previous studies by incorporating a significant number of additional spectra and precise determination of frequencies. Four frequencies were identified for this star: 1.6774 ± 0.0002 d−1, 1.4174 ± 0.0002 d−1, 0.0714 ± 0.0002 d−1, and 1.8228 ± 0.0002 d−1 which were identified with the modes (l,m) = (1, +1), (1, +1), (2, −2), and (1, +1) respectively. These findings are in agreement with the most recent literature. The prevalence of (l,m) = (1, +1) modes in γ Doradus stars is starting to become apparent and we discuss this result.
Type 1 Diabetes and Prediabetic State in a Monozygotic Triplet
Authors: Krokowski M. , Abel M. , Teodorczyk A. , Szadkowska A. , Pyrżak B. , Rymkiewicz-Kluczyńska B. , Bodalski J.
Published: July 2016

Type 1 diabetes mellitus (IDDM) results from a chronic process of autoimmune destruction of ß cells of the Langerhans islets. The presence of autoantibodies (ICA, GADA, anti-IA2, IAA) in serum preceds the clinical onset of the disease. Genetic predisposition for IDDM is connected with HLA, CTLA-4 and insulin gene region.

The aim of the study was the genetic and immunological analysis of a triplet. One of them developed Type 1 diabetes mellitus. We analysed HLA class II, CTLA-4 and insulin gene polymorphisms in the whole family. Besides, we investigated immunological status of three brothers.

All patients present identical genotype for VNTR loci: D1S80, D17S5 and Apo B, as well as for HLA-DRB1, — DQA1, — DQB1, CTLA-4 gene and all studied insulin gene polymorphisms. That proves their monozigosity. The triplet presents strong genetic predisposition for IDDM. The two patients without overt diabetes have increased levels of ICA, GADA, IA2 and IAA.
From the Research on Electrophoretical Mobility of Nuclei in Twins
Authors: Rębacz E.
Published: July 2016

I studied 8 pairs of male twins and 14 pairs of female twins. The aim of this paper is to demonstrate the evaluation of development age in pairs of twins examined through the electrophoretical mobility of nuclei. EMN index in pairs of male twins, the index figures do not change dramatically between the ages of 8 – 12. EMN index in pairs of female twins rises from 9 – year – old to 11 – year – old pair. In this paper I want to indicate the studies on development age, which began at The Twins Festival in Szczecin in 1998.
A Comparative Study of Twinning and Triplet Rates in 17 Countries, 1972-1996
Authors: Imaizumi Y.
Published: July 2016

Secular changes in twinning and triplet rates were analyzed using vital statistics in Austria, the Czech Republic, the Slovak Republic, England and Wales, Germany, the Netherlands, Switzerland, Denmark, Finland, Norway, Sweden, Canada, Australia, Hong Kong, Israel, Japan, and Singapore during the period from 1972 to 1996. Among those 17 countries, the twinning and triplet rates in the Czech Republic and in the Slovak Republic remained constant from 1972 to 1994, whereas these rates increased significantly year by year in the other 15 countries during the examined period in each country. Twinning rates increased from 1.2-fold in Austria to 2-fold in Denmark from 1972 to 1996. As for triplets, the rate increased from 3-fold in Denmark to 9-fold in Norway during that period. With one exception, that being the Slovak Republic, the triplet rate was highest in the Scandinavian countries, followed by the other European and Asian countries. The rising twinning and triplet rates have been attributed to the higher proportion of mothers treated with ovulation-inducing hormones and partially attributed to IVF.
Ultrasound Examination in Twin Pregnancy and Late Fetal Death
Authors: Rydhstroem H. , Walles B.
Published: July 2016

Objective. To test the hypothesis that the (case) twin later to succumb in utero has biparietal diameter measurements (by ultrasound) different from those (control) twins surviving the perinatal period.

Material and methods. Information from the Medical Birth Registry, National Board of Health and Welfare, Stockholm, was used to identify all births in a defined population in southern Sweden with about 20,000 deliveries each year. In 3,019 twin pregnancies between 1973 and 1989, one or both twins were stillborn in 47 cases (gestational duration ≥28 weeks, birthweight ≥500g.). For each case pregnancy, two control pregnancies were selected, the matching criteria being: same delivery unit, same parity (0, I, II, III+), similar year of delivery (± 1 year) and maternal age (± 5 years). Data on ultrasound examinations were extracted from the original medical records. Screening in early second trimester started at one of the units as early as 1973 and at the latest of 12 units in 1982.

Results. There was no obvious difference between cases and controls in intra-pair discordant biparietal diameter (BPD) measured in early second trimester. Nor was there any evident difference in the rate of deviant BPD between cases and controls. In all, 8% of dead male and 24% of dead female fetuses were by definition small-for-gestational age (<-2 standard deviations).

Conclusions. No significant difference was seen between cases and controls regarding deviating biparietal diameters. Abdominal diameter may be a better predictor of subsequent fetal death (not analysed in this study), though only about 15% of all dead twins were deemed small-for-gestational age.
Trends of Twinning Rates in Ten Countries, 1972-1996
Authors: Imaizumi Y.
Published: July 2016

Trends of twinning rates were analyzed using vital statistics in Austria, Finland, Norway, Sweden, Canada, Australia, Hong Kong, Israel, Japan, and Singapore during the period from 1972 to 1996. The twinning rates increased significantly year by year in each country. During these periods, the twinning rate increased by twenty percent in Austria and Canada, and by sixty percent in Norway and Sweden. The twinning rate was 1.6 times higher in Sweden than in Hong Kong in 1972 and by eighty percent in Israel in 1995. Twinning rates were higher in European countries, Canada, and Australia than in Asia. The variations of the twinning rates among countries were not only due to biological factors, but also to assisted reproductive techniques. In Australia, the overall twinning rate was 1.3 times higher in the nuptial births (14.1 per 1000 births) than in the ex-nuptial births (10.7) during the period 1994-1996. As for maternal age, twinning rates in Sweden increased year by year for maternal age groups except the youngest and the oldest age groups. In Sweden, the rising twinning rate has been attributed to the higher proportion of mothers (for the 25-39 year old age groups) treated with ovulation-inducing hormones and attributed to in-vitro fertilization.
Balanced X; 22 Translocation in a Patient with Premature Ovarian Failure
Authors: Banerjee N. , Kriplani A. , Takkar D. , Kucheria K.
Published: July 2016

A case of balanced X; autosome translocation 46, X, t (X; 22) (q 24; q 13) in a 25-year-old female with secondary amenorrhea and premature ovarian failure (POF) is described. The relationship between balanced X; autosome translocation [t (X; A)] and varied phenotypic expression observed in these women is discussed. This case highlights the importance of early recognition of these women in order to give them the best chance of conception in their oligohypomenorrhic phase before complete loss of gonadal function.
Very Early and Simple Determination of Chorionic and Amniotic Type in Twin Gestations by High-Frequency Transvaginal Ultrasonography
Authors: Malinowski W.
Published: July 2016

Objective. The aim was to determine the chorionic and amniotic types in multifetal pregnancies with transvaginal ultrasonography at very early stage of gestation.

Study design. Twenty-one spontaneous multifetal pregnancies were scanned transvaginally before 8 weeks' gestation (four of them from 4th week). The chorionic and amniotic type was determined ultrasonographically. All twin gestations had postpartum pathologic evaluation of the placenta and histologic determination of the chorionic and amniotic type.

Results. Ultrasonographic evaluation of the 21 pregnancies demonstrated 20 twin and 1 triplet gestation. Four of the twin pregnancies were monochorionic-diamniotic. Triplet was monochorionic-triamniotic (spontaneously aborted in 8th week of gestation). In all 20 twin pregnancies, transvaginal ultrasonography correctly predicted the chorionic and amniotic type before 8 weeks of gestation.

Conclusion. Transvaginal ultrasonography allows a reliable, simple and rapid determination; the dichorionic twin pregnancy in 4 weeks, monochorionic in 5 weeks, and differentiation of mono-or diamniotic in 7 weeks of gestation.
Contributions of Mouse Genetic Studies to Genomic Imprinting
Authors: Cattanach B.M.
Published: July 2016

Maternal and paternal disomies and equivalent duplications for specific chromosome regions can readily be generated in the mouse. Most do not result in abnormality but for 10 regions distributed over 6 chromosomes developmental anomalies ranging from early embryonic lethalities to characteristic phenotypic abnormalities occur. With certain chromosome regions, maternal or paternal duplication leads to different and, in some cases, opposite anomalies so that, in total, 15 different imprinting effects can be distinguished. These observations have provided key evidence on the occurrence of imprinting in mammals.

On the basis of the established homologies between mouse and human chromosomes, it is possible to predict which segments of the human genome are subject to equivalent imprinting. In this regard it is significant that candidate imprinting effects for the two classical examples of imprinting in humans, namely the Prader-Willi and Angelman syndromes, have been found in the mouse.

Current studies are aimed at reducing the size of the imprinting regions with the objective of facilitating identification of the genes involved. Furthermore, the developmental profiles of genes already identified as being subject to imprinting are being determined.

A new approach involves the analysis of a novel mutation that causes growth retardation and cranial abnormalities and which shows the inheritance pattern of an imprinted gene, as originally predicted by Hall (Am J Hum Genet 46: 857, 1990). It is anticipated that the mutation will represent a deletion and will lie within one of the recognised imprinting regions.
Wiedman-Beckwith Syndrome, Tumorigenesis and Imprinting
Authors: Junien C.
Published: July 2016

WBS is an overgrowth malformation syndrome characterized by highly variable expressivity, associated with predisposition to different types of pediatric tumors including Wilms' tumor (WT), adrenocortical carcinoma (ADCC), rhabdomyosarcoma (RMS) and hepatoblastoma (HEP). Most cases are sporadic, however 15% of the cases are familial. Cytogenetic, genetic and molecular analysis of the different forms of this syndrome and associated tumors have provided increasing evidence that the gene (or genes) map to 11p15.5 and that genomic imprinting can account for the strange genetics of this syndrome/tumors [1]. Two candidate genes, H19 and Igf2, which are both imprinted, but in opposite direction, map close to but not within one of the two smallest region(s) defined both by constitutional and tumoral rearrangements. These two genes, H19 and Igf2, and their specific parental imprint, may thus account for the pattern of inheritance observed, the variable expressivity, the specific loss of alleles and the loss of imprint. However, that these genes map 400 kb away from one cluster of breakpoints observed in the cytogenetic cases of WBS suggests that other genes could be involved. Indeed, although mapping to a different subregion, a sequence wit the properties of a tumor Suppressor (rhabdomyosarcoma cell line) has recently been isolated [2].

Furthermore, neither reduplication of the active Igf2 paternal allele nor relaxation of Igf2 imprinting is sufficient for tumorigenesis, thus indicating that other mutation(s) must occur. The phenotypic consequences of these aberrant expressions will be better understood when the tissues, the stage of development or the state of differentiation are precisely identified [3-5].
Isochromosome 15q of Maternal Origin in a Prader-Willi Patient with Pituitary Adenoma
Authors: Bettio D. , Giardino D. , Rizzi N. , Riva P. , Volpi L. , Barantani E. , Tagliaferri A. , Larizza L.
Published: July 2016

We report on a Prader-Willi syndrome (PWS) patient carrier of a balanced 15q15q translocation and affected by a prolactin-secreting pituitary adenoma. Evidence provided by molecular studies indicates that the structural rearrangement is an isochromosome of maternal origin. According to the identification of isodisomy as the basis of the association of rare disorders and the recent report on chromosome 15 monosomy and nullisomy in pituitary adenoma, we suggest that in our case PWS and pituitary adenoma might be related.
Secular Changes of Twinning Rates in Nordic Populations
Authors: Eriksson A. W. , Abbott C. , Kostense P. J. , Fellman J. O.
Published: July 2016

In each species, natural selection has resulted in an optimal litter size, to ensure the largest average number of surviving offspring and the lowest maternal mortality. The terrestrial insectivores from which the primates evolved had large litters. It has been argued that in primates adaptation to an arboreal mode of life led to a reduction of litter size to a single offspring because of the difficulty of producting and caring for a large litter in a tree [6]. A recent critical survey of the literature indicates that twinning frequency in most nonhuman primates is lower than in man [20].

There are clear ethnogeographic differences in the incidence of human twinning. Among peoples of Eastern Asia, multiple maternities are rare; in Japan for instance, the twinning rate is only 3-7 per mill, according both to the official statistics and hospital records. These low rates seem not to be caused by the facts that it is customary in Japan to have children very early in life or that twin births were at one time viewed with displeasure and concealed, or sometimes twins were even killed in some areas [21].

In hospital series among some Negro tribes almost 10 times higher twinning frequencies than among Japanese have been reported e.g. the Yorubas in western Nigeria with values above 60 per mill [24]. However, where national birth statistics of Blacks are available, twinning is lower, e.g. in U.S.A. 13-15 per mill [1].
Annual Variation of Sex Ratio in Twin Births and in Singletons in Brazil
Authors: Beiguelman B. , Franchi-Pinto C. , Colletto G. M. D. Dal , Krieger H.
Published: July 2016

The annual variation of the sex ratio (SR) of 1385 twin births was analyzed and compared to that of 85909 singletons. These births referred not only to live births but also to stillbirths in two southeastern Brazilian maternity hospitals from 1984 to 1993. While the annual variation of the SR of singletons was very small, that of twin births was extremely high, due to the significant heterogeneity of the annual data. It is suggested that the large SR annual variation of the twin birth might be a consequence of the variation of male or female monozygotic twins.The hypothesis that twin births show a lower sex ratio than singletons could not be supported by the present data.
Intrapair Differences of the Blood Cell Components and Lymphocyte Subsets in Monozygotic and Dizygotic Twins
Authors: Yokoyama Y. , Akiyama T.
Published: July 2016

We evaluated the relative influence of genetic and environmental factors on leukocytes, lymphocytes, neutrophils, monocytes, erythrocytes, reticulocytes, hemoglobin, platelets, T lymphocyte subsets, and NK marker cells in monozygotic (MZ) and dizygotic (DZ) twins. Peripheral blood components were measured in 154 healthy twin pairs (118 MZ pairs and 36 DZ pairs) and lymphocyte subsets in 48 healthy twin pairs (38 MZ pairs and 10 DZ pairs).

Platelets and erythrocytes showed higher intraclass correlations in the MZ pairs than in the DZ pairs in the males. However, in the females, the intraclass correlations for these components were similar between the MZ and DZ pairs. Neutrophils and monocytes showed low intraclass correlations in the MZ pairs. The absolute number of CD4+cells and the CD4+/CD8+cell ratio showed high intraclass correlations regardless of age in the MZ pairs in both males and females. The intraclass correlation for the absolute number of CD3+cells was low in pairs aged ≥ 60 years in the MZ pairs. The absolute numbers of CD16+cells and CD56+cells showed high intraclass correlations regardless of age in the MZ pairs.
Prenatal Weight Gain and the Birthweight of Triplets
Authors: Luke B. , Bryan E. , Sweetland C. , Leurgans S. , Keith L.
Published: July 2016

The objective of this study was to evaluate the association between maternal factors, including rates of gestational weight gain before and after 24 weeks' gestation, and adequacy of intrauterine growth for gestational age at birth of triplets, as a mean Z-score of the triplet set. The study design was a retrospective, anonymous, pilot telephone survey of mothers of triplets and an historical cohort analysis of their prenatal weight gain records. The statistical analyses performed included multiple regression analysis to formulate a model for mean triplet Z-score (a measure of birthweight-for-gestational age) and analysis of variance to confirm and simplify the components of this model. Factors significant in the final model and their beta coefficients included weeks' gestation (-0.124, p <0.0001), rate of gain before 24 weeks' gestation (0.606, p = 0.005), and induced conception (−0.404, p = 0.01). Rate of gain > 1.5 lbs/week before 24 weeks was significant in the analysis of variance (p = 0.009). Better intrauterine growth for gestational age is achieved in triplet gestations with maternal weight gains of >1.5 lbs/week before 24 weeks' gestation.
Accommodating a Twin Pregnancy: Maternal Processes
Authors: der Zalm J. E. Van
Published: July 2016

The object of this study was to develop a theory of the relationship between a mother and her unborn twins using a qualitative grounded theory methodology. Ten women participated in interviews during the last trimester of a twin pregnancy and again during the early postpartum period. Data provided by these women was analysed using the constant comparative method. Two additional informants were sampled in order to formulate and verify the tentative theory. For women in this study, the findings indicate that mothers form a relationship with their unborn twins within the wider context of accommodating the twin pregnancy in their lives. A woman accomplishes this process by immediately seeking information about twin pregnancy, by making room, in all senses, for two babies instead of one in her life, and by appraising her own pregnancy risk. A mother engages in self-protective behaviors and in behaviors designed to protect the health of her unborn twins as a method of coping with the perceived risk of the twin pregnancy and with the twin pregnancy itself. As the twin pregnancy progresses, women move toward accepting the idea of being pregnant with twins. For women pregnant with twins, the birth of two infants confirms the reality of the pregnancy.
Hypertensive Disorders in Twin Pregnancies
Authors: Chaim W. , Fraser D. , Mazor M. , Leiberman J. R.
Published: July 2016

This study investigates the influence of hypertensive disorders on twin pregnancies for an unselected, population-based series. Between 1986 and 1991, out of a total of 56,381, 766 (1.3%) were twin deliveries at our institution, the only tertiary care hospital serving a population of about 400, 000 inhabitants. The incidence of hypertensive disorders was significantly higher in twin gestations than in singleton pregnancies, at 3437/55,615 (6.2%) vs 85/766 (11.1%) (p<0.001, OR=1.8, 95% CI =1.4-2.3). Hypertensive disorders were significantly higher in twin as compared to singleton pregnancies, regardless of parity, and even after adjusting for maternal age. More instrumentai or surgical deliveries were needed when pregnancies were complicated by hypertension, in twin as well as singleton gestations. Despite the association between prematurity and hypertensive disorders, and prematurity and perinatal mortality, no significant difference was found in perinatal mortality between hypertensive and nor-motensive twin pregnancies. The neonatal death-rate in normotensive and hypertensive twin pregnancies (3.7% and 3.5% respectively) was higher than that of stillbirths (respectively 2.3% and 0%).
Low Birthweight in Twins: Black and White Differences
Authors: Waller P.L. , Ross A. , Hoskins R.E. , Daling J.R.
Published: July 2016

Washington State birth certificate data for the years 1984-1988 were analyzed for 2,804 mothers of twins in order to determine whether black mothers of twins have a higher risk of delivering a low birthweight twin infant than white mothers. Seventy four percent of black mothers of twins gave birth to an infant weighing < 2500 grams (white 52.9%), while slightly less than 20% gave birth to an infant weighing <1500 grams (white 9.4%). After adjustment for maternal age, parity and marital status, the risk of black mothers giving birth to at least one twin infant <2500 grams relative to white mothers was 1.3 (95% confidence interval, 1.2, 1.5). When this analysis was restricted to very low birthweight babies (<1500 grams), the relative risk for infants of black mothers compared to white mothers adjusted for the same factors was 2.1 (95% confidence interval, 1.5, 3.0). The frequency of neonatal mortality in the study population was also assessed. The overall frequency of mortality in black twin infants was double that in white twins infants. When stratified by birthweight category, the frequency was higher in white infants (30.2%) than in black infants (24.1%) weighing less than 1500 grams at birth. However, within higher birthweight categories, (≥1500 grams to <2500 grams and >2500 grams), relative frequencies of neonatal mortality were higher in black infants. This analysis reveals that black mothers of twins are more likely to deliver low birthweight twin infants than white mothers. The increased risk is even more pronounced in very low birthweight twin pairs. However, the additional risks for low birthweight black twin pairs and very low birthweight twin pairs found in this study are lower than the risk increase commonly reported for the respective birthweight categories in black singleton infants relative to white singleton infants. This implies that while black twin pregnancies require many of the same special antepartum considerations given to black singleton pregnancies, the increased baseline risks associated with low birthweight and very low birthweight twin deliveries offset racial disparities traditionally seen in singleton infants.
Confirmatory Factor Analysis of Reading and Mathematics Performance: A Twin Study
Authors: Gillis J.J. , DeFries J.C. , Fulker D.W.
Published: July 2016

Reading and mathematics performance data from a sample of 264 reading-disabled twin pairs and 182 matched control twin pairs were subjected to multivariate behavior genetic analysis. The factor structure of reading and math performance measures was found to be highly similar for both groups. Consistent with previous findings obtained using alternative methods, a significant heritable component to individual differences in reading performance was found both within the reading-disabled (h2 = 0.78) and control (h2 = 0.74) twin samples. In addition, a substantial genetic influence on mathematics performance was found (h2 = 0.51 and 0.60 in the reading-disabled and control samples, respectively), although shared environmental influences common to both members of a twin pair also contribute significantly to the variance in math scores of both groups (c2 = 0.44 and 0.37). Moreover, genetic influences accounted for 98% of the observed correlation between reading and math performance within the sample of reading-disabled twin pairs, and for 55% of the observed correlation in the control sample. Thus, individual differences in both reading and mathematics perfomance are highly heritable and appear to be caused by many of the same genetic influences.
Alcohol Use, Smoking Habits and the Junior Eysenck Personality Questionnaire in Adolescent Australian Twins
Authors: Hopper J.L. , White V.M. , Macaskill G.T. , Hill D.J. , Clifford C.A.
Published: July 2016

In 1988, questionnaires were received from 1,400 twin pairs (17% MZM, 23% MZF, 17% DZM, 19% DZF, 24% DZO) aged 11 to 18, registered with the Australian NHMRC Twin Registry. Twins reported independently on themselves and on the perceived behaviour of their parents, siblings and friends. For smoking and for drinking in the previous month, the prevalence was modelled as a logistic function of age, sex, perceived smoking or drinking behaviour of family and friends, and the Junior Eysenck Personality Questionnaire (JEPQ) scales. Strenghts of association were: family behaviour, odds ratio (OR) ≤2; Extraversion and Psychoticism, interquartile OR ≈ 1.6; behaviour of friend, OR ≈ 3 to 6. Twin associations were represented by odds ratios. For smoking they were 16 in MZ and 7 in DZ same-sex pairs, and 3 in DZO pairs. Although the former is consistent with genetic factors determining adolescent smoking behaviour, the reduced association in DZO pairs and strong association with smoking by friends argue to the contrary. For drinking, twin odds ratios were 11 in MZM, MZF and DZF pairs, and 4 in DZM and DZO pairs, consistent with genetic factors determining alcohol use in male but not female, adolescents. Twin odds ratios were not influenced by adjustment for the JEPQ scales; this does not support the hypothesis that genetic factors which determine personality also determine smoking or drinking behaviour during adolescence.
From Puberty to Mid-life: A Follow-up Study of Twins and Controls
Authors: Lange A-L. , Fischbein S.
Published: July 2016

During the years 1964 to 1971 a group of twins and a control group of singletons in the same classes, were followed from grade 3 at 10 years of age to grade 9 at 16 years of age in the Swedish compulsory school. The study was called the SLU-project (Skolöverstyrelsens och Lärarhögskolans Utvecklingsprojekt) and the main purpose was to study physical and mental growth during puberty as well as heredity and environment influences on these growth processes. Originally 323 twin pairs, MZ and DZ, and 1193 controls were included in the sample. Among the DZ twin pairs there were both same-sex and opposite-sex pairs. They were a nationally representative sample. Several kinds of information were collected, such as, a) Physical measurements (height and weight measurements, menarche, ratings of secondary sex characteristics); b) Ability and achievement measures (intelligence tests, standardized achievement tests); c) Self ratings; d) Ratings by teachers and classmates; e) Socioeconomic background data (fathers occupation and income). For the boys, supplementary data on physical growth and mental ability was collected on enrollment to military service at the age of 18. In this pilotstudy, we have made a follow-up of the original SLU-sample after 20 years. They are now in their mid-thirties. The main purpose has been to investigate if they are willing to participate in a new study on health and well-being at mid-life.
A Twin Study of Odor Identification and Olfactory Sensitivity
Authors: Segal N.L. , Brown K.W. , Topolski T.D.
Published: July 2016

Interindividual variation in odor identification and olfactory sensitivity has been explained primarily with reference to age, sex and/or experiential factors. A twin study of olfaction can, therefore, substantially contribute to current research in this area. Thirty-nine monozygotic and twenty dizygotic twin pairs have completed the University of Pennsylvania Smell Identification Test (UPSIT), an olfactory preference questionnaire, and two odor detection threshold tests (phenyl ethyl alcohol and butanol). A genetic influence on odor identification, as assessed by the UPSIT, has been demonstrated. Future plans and directions for this research program are discussed.
Within-pair Similarity in MZ and DZ Twins from Birth to Eighteen Years of Age
Authors: Åkerman B. Alin , Fischbein S.
Published: July 2016

This study is based on 145 pairs of twins included in a longitudinal study of a cohort of singletons born in 1953 and living in the Stockholm metropolitan area in 1963. Of these 145 pairs, 28 were classified as MZ, 103 as DZ and 14 pairs could not be classified. School achievement and ability test results have been collected for this group as well as data for the boys from physical and mental examinations on enrollment to military service. The purpose of this study was to compare within-pair similarity for MZ and DZ twins from birth onwards. There seems to be a divergent trend over time for MZ twin pairs to become more similar and DZ twin pairs to become less similar in height growth, school achievement and verbal ability. This is in accordance with previous research in this field. In relating similarity within pairs to birthweight, we found a drop in within-pair similarity for low birthweight MZ and DZ twin pairs (both twins ≤2.500 g), but not for normal weight twin pairs. A discussion is initiated concerning methodological implications of these results.
Secular Trend and Associated Factors of Twinning in Taiwan
Authors: Chen C.J. , Lee T.K. , Wang C.J. , Yu M.W.
Published: July 2016

Delivery records of public hospitals and local health centers were analyzed to investigate the secular trend of multiple births from 1955 to 1990 in Taiwan. Twinning rates decreased gradually from the late 1950s to 1973, slightly increased and remained stable from 1974 to 1980, and then increased strikingly from 1981 to 1990. During the study period, MZ rates were consistently higher than DZ rates except in 1986 when a higher DZ rate was observed. The highest MZ rate of 7.7 per 1,000 deliveries was observed in 1985, while the highest DZ rate of 4.6 per 1,000 deliveries was observed in 1986. The triplet incidence rate also declined from the early 1960s to 1973 and then increased markedly from 1974 to 1990. A case-control study including 482 MZ and 252 DZ twin pairs and 1,496 singletons was carried out in four teaching hospitals in Taipei City between October 1985 and June 1989 to examine factors related to twinning. The zygosity of twin pairs was determined by sex, placentation and red blood cell antigens. Multiple logistic regression analysis showed that the higher the maternal age, the lower the MZ and DZ rates, while the higher the parity, the higher the rates. There was no association of paternal age or of maternal educational level with twinning rates
Intrauterine Death in Multiple Gestation
Authors: Liu S. , Benirschke K. , Scioscia A.L. , Mannino F.L.
Published: July 2016

Intrauterine death of one fetus in a multiple gestation is associated with significant morbidity and mortality in the surviving infant. This study is a retrospective review of 38 twin and 3 triplet gestations involving the intrauterine death of at least one fetus. The obstetrical history, placental pathology, autopsy findings, and neonatal history of the surviving infant are reviewed. Three cases involved the recent stillbirth of both twins, the remaining cases involved a surviving infant. In one case, neonatal death of a surviving twin occurred on day 19. In two sets of triplets, two stillbirths occurred, in the third case two infants were liveborn. The incidence of preterm delivery was 34%, which decreased to 18% if fetal cotwin death had occurred before 20 weeks gestation. Cesarean section was the method of delivery in 16 cases. There was an excess of velamentous cord insertions, which was most pronounced in the stillborn twin. Monochorionic placentation was found in 72%, also an excess.

Neurological damage was known to have occurred in 19 of the 39 surviving infants. Fifteen of these 19 (79%) were associated with monochorionic placentation. The neurologically damaged twin infants, when compared to the normal infants, had the cotwin die later in gestation (31 vs 16.5 weeks), had a shorter duration between the death of the cotwin and delivery (2.5 vs 21 weeks), and delivered earlier in gestation (36.5 vs 39.5 weeks). The probable cause of neurological damage, in our opinion, was either exsanguination into the dead twin fetus, or disseminated intravascular coagulation which occurred in at least 13 cases. The incidence of antepartum death in a multiple gestation, and the potential for neurological damage is probably higher than previously thought. A review of the literature is presented and the clinical implications of this phenomenon are discussed.