bluuebunny/crossref_metadata_2025 huggingface dataset:
Delayed meiotic development and correlated death of spermatocytes in male mice with chromosome abnormalities
Authors: Speed R.M. , De Boer P.
Published: May 2008

The kinetics of germ-cell development were examined in random-bred adult Swiss mice by means of tritium autoradiography. Comparisons were made between males with normal (+/+) and abnormal karyotypes: Rb(l 1.13)4Bnr/+ and T(1;13)70H/+ heterozygotes, T70H tertiary trisomies, andT70H translocation trisomies. The time taken for the first wave of labelled cells to progress from premeiotic S-phase to diplotene and then on to the second meiotic metaphase was estimated in each stock, and rates of increase of labelled meiotic figures were measured. The S-phase to diplotene interval did not differ significantly among the different genotypes, taking from 10 days, 16 h to 10 days, 19 h. In Rb4Bnr/+, T70H translocation trisomic, and T70H tertiary trisomic males, however, labelled meiotic figures accumulated at a lower rate, particularly in the tertiary trisomies. A cell delay for some meiocytes was thus indicated during meiotic prophase. A correlation was seen between the degree of meiotic delay and severity of reduction in sperm count. The period from late diplotene to metaphase II was also found to be longer in T70H tertiary trisomies than in controls (+/+) or other chromosomally abnormal males.
Chromosomal phylogeny of Muridae: a study of 10 genera
Authors: Viegas-Péquignot E. , Dutrillaux B. , Prod’Homme M. , Petter F.
Published: May 2008

The karyotypes of 10 different species of the family Muridae (Acomys airensis, Arvicanthis niloticus, Hylomyscus stella, Malacomys longipes, Mastomys huberti, Myomys daltoni, Mus musculus, Rattus norvegicus, Thamnomys gazellae, and Uranomys ruddi) are compared by different banding techniques. From a reconstruction of the presumed ancestral karyotype of the Muridae the sequence of the various rearrangements leading to the present karyotypes is proposed in order to determine their phylogenetic relationships. In particular, the present karyotypes of the mouse and rat differ from the ancestral one by at least 12 and 7 rearrangements, respectively. A clear tendency for accumulation of a specific type of rearrangement in a given branch of the cladogram is observed. In regard to the mouse, a large number of translocations, with break points situated in the proximal part of the long arms, have occurred, which conserved the acrocentric form of the ancestral chromosomes but led to multiple recombinations of the bands.
Two new X-autosome translocations in the mouse
Authors: Searle A.G. , Beechey C.V. , Evans E.P. , Kirk M.
Published: May 2008

The reciprocal translocations T(X;4)37H and T(X;11)38H were induced by acute X-irradiation of spermatozoa. Male heterozygotes are completely aspermic with a spermatogenic block at pachytene and testis masses about one third of normal, though metaphase I is very occasionally reached in T37H. For both translocations the X chromosome breakpoints are in band XA2, and the autosomal breakpoints are in 4D3 for T37H and 11E1 for T38H, leading to long and short marker chromosomes. Chain quadrivalents predominated in oocytes at MI, with no rings; there were 32% trivalent + univalent configurations in T37H and 40% in T38H. These generated (1) XO mice, (2) tertiary trisomies carrying 20 bivalents and the small X4 (T37H) or X11(T38H) markers. These trisomies were apparently lethal in T37H but sub-viable in T38H and sometimes fertile as XX11 and trisomic XXX11 females, though sterile as XX11 Y males. However, many developed exencephaly in utero, probably because of the distal duplication on chromosome 11. No tertiary monosomies were found in 12 to 14 day embryos. Seven percent of all female progeny were XO, with a higher than expected frequency in T37H and a lower than expected one in T38H. T37H is about two units and T38H about five units from the spf locus on the X chromosome with evidence for some crossover suppression between the T38H breakpoint and Ta. Autosomal linkages found were T37H-ra-6 (R.F. of 16 + 4% between T37H and m) and T38H-/Rewc (R.F. of 5 + 3%). T37H/+ females weighed about 10% less than normal females at birth and about 30% less at weaning; there was little if any effect in T38H/+ females or in males carrying either translocation. Neither translocation had any marked effect on viability. T37H/ + females showed variegation when heterozygous for b with the wild type allele in the long 4X marker. On average, about 20% of the coat was brown rather than black. However, no clear evidence for m variegation was found.
Nucleolus organizer regions of the canine karyotype
Authors: Howard-Peebles P.N. , Howell W.M.
Published: May 2008

Silver-stained preparations of cultured lymphocytes obtained from 12 pure-bred dogs revealed the presence of nucleolus organizer regions (NORs) on four to seven chromosomes in females and five to eight chromosomes in males. All seven males had a NOR on the Y chromosome. The telomeric location of the NORs on the autosomes suggested by an earlier study was confirmed.
Sperm chromosome analysis of a man heterozygous for a pericentric inversion of chromosome 3
Authors: Balkan W. , Burns K. , Martin R.H.
Published: May 2008

Using a procedure in which human sperm were allowed to fertilize zona-free golden hamster (Mesocricetus auratus) eggs in vitro, the sperm chromosomes of a man heterozygous for inv(3) (p1 1 q 11) were analyzed. When the chromosomes were Q-banded, the inverted chromosome had the bright centromeric band on the short arm rather than on the long arm, as was seen in the normal No. 3. One hundred and eleven sperm chromosome spreads were examined, of which 64 contained the normal chromosome and 47 the inverted one. This was not significantly different from the expected 1:1 ratio. No sperm containing a chromosome imbalance caused by a crossover within the inversion were seen. Ten (8.1%) of the sperm contained chromosome abnormalities unrelated to the inversion. The ratio of X- to Y-bearing sperm was 55:45.
Localization of a gene controlling the expression of the human transferrin receptor to the region q12→qter of chromosome 3
Authors: van de Rijna M. , Geurts van Kessel A.H.M. , Kroezen V. , van Agthoven A.J. , Verstijnen K. , Terhorst C. , Hilgers J.
Published: May 2008

A monoclonal antiserum, 66-IG10, raised against human thymocytes was found to be directed against the human transferrin receptor. A panel of human x Chinese hamster somatic cell hybrids, in conjunction with the 66TG10 reagent, was used to assign the gene(s) coding for the transferrin receptor to the ql2→qter region of human chromosome 3.
Chromosomal evolution in Malagasy lemurs
Authors: Rumpler Y. , Couturier J. , Warter S. , Dutrillaux B.
Published: May 2008

A chromosomal banding study was carried out on Propithecus verreauxi verreauxi, P. verreauxi deckeni, and Avahi laniger laniger. Comparison of their karyotypes with those of Microcebus murinus and Lemur fulvus led to reconstruction of the ancestral Lemuriform karyotype and a determination that the branch leading to the Indridae was isolated very early, before the separation of the Lemuridae from the Cheirogaleidae. The karyotype of Avahi remained highly ancestral, whereas that of P. verreauxi was considerably modified, chiefly by Robersonian translocations.
Chromatin organization and restriction endonuclease activity on human metaphase chromosomes
Authors: Mezzanotte R. , Bianchi U. , Vanni R. , Ferrucci L.
Published: May 2008

Human metaphase chromosomes were treated with Haelll, Hindlll, EcoRI, and Alul restriction endonucleases and subsequently stained with either Giemsa or ethidium bromide. The results obtained seemed to suggest that the structural organization of specific chromosome regions can play a primary role in determining the cytological effect after digestion with specific restriction endonucleases.
Synaptonemal complex analysis of chromosome rearrangements in domestic fowl, Gallus domesticus
Authors: Kaelbling M. , Fechheimer N.S.
Published: May 2008

Electron microscopy of synaptonemal complexes in heterokaryotypic Gallus domesticus cockerels revealed that chromosome rearrangements that had been classified by light microscopy as single breaks were in fact reciprocal translocations. A microchromosome provided the centromere for the acentric long arm of chromosome 1 in a rearrangement that had been classified as a centric fission, and microchromosomes were involved in several other rearrangements. The translocation points were mapped in three of the rearrangements.
Involvement of chromosome 6 in rearrangements in human malignant melanoma cell lines
Authors: Pathak S. , Drwinga H.L. , Hsu T.C.
Published: May 2008

We analyzed the karyotypes of nine established human malignant melanoma cell lines derived from two female and six male patients. Each of the cell lines had an aneuploid stemline chromosome number. Analysis of G-banded chromosomes identified a number of altered (marker) chromosomes in these cell lines; in all the lines, chromosome 6 was found to be involved in the marker chromosomes. A review of the literature and these cases showed that of 47 cell lines or primary melanoma cells karyotyped, 38 (80.8%) had a marker involving the 6. We believe that the genetic factor determining melanoma initiation is located in the distal segment of 6q. Deletion of this segment or the entire 6q is responsible for the cell’s (melanoblast or melanocyte) becoming malignant. The proximal segment of 6q and 6p can be involved in marker formation.
The Possibility of detecting fetal lymphocytes in the maternal blood of the domestic pig, Sus scrofa
Authors: Rudek Z. , Kwiatkowska L.
Published: May 2008

Fourteen pregnant sows were examined to determine if transplacental migration of fetal lymphocytes had occurred. Giemsa-stained and C-banded karyotypes were examined. Male metaphases constituted 1 % to 4% of all metaphases of peripheral blood leukocytes of pregnant sows. Regardless of the experimental method or stage of gestation, no essential differences were found in the number of male cells.
Elimination of mycoplasma contamination from mammalian cell cultures by the bibenzimidazole derivative Hoechst 33258
Authors: Hellkuhl B. , Grzeschik K.-H.
Published: May 2008

Cell cultures contaminated with mycoplasma or bacterial L-forms were treated with 8 µg/ml of Hoechst 33258. No microorganisms could be detected by fluorescence microscopy after two rounds of treatment.
Sex determination in the European eel (Anguilla anguilla, L.)
Authors: Wiberg U.H.
Published: May 2008

Metaphase chromosomes from cultured blood cells of female, male, and hermaphroditic European eels were analyzed. In addition, both gonads from each of the specimens were examined microscopically to ensure correct sexing. The karyological investigation revealed that in some of the specimens a heteromorphic chromosome pair was present. This heteromorphism appeared in both sexes and in the hermaphrodite. C-banding and silver nitrate staining demonstrated that the heteromorphism was due to quantitative differences in constitutive heterochromatin and nucleolar organizing regions in the short arm of chromosome 8. In G-banded preparations it was demonstrated that, except for the heteromorphism mentioned, the karyotypes from both sexes and the hermaphrodite were identical. With the G-band technique it was also easily demonstrated that both the largest metacentric (No. 1) and the smallest metacentric (No. 11) had homologs. Therefore, in contrast to some earlier reports which claimed that these two chromosomes were a heteromorphic pair of sex chromosomes, it is concluded that Anguilla anguilla has no heteromorphic sex chromosomes. The implication of these findings are discussed in relation to the many reports of strongly skewed sex ratios found in commercial eel farms. It is tentatively hypothesized that sex determination in A. anguilla may be metagamic and that sex inversion may occur in this species.
Structural correlates of cellular tumorigenicity and anchorage independence in transformed fibroblasts
Authors: Kahn P. , Heller D. , Shin S.
Published: May 2008

The ability on nonhematopoietic cells to proliferate in vitro without attachment to a solid surface (anchorage independence) is known to be highly correlated with their ability to form tumors in nude mice. Transformed cells in vitro frequently also show less organization of the intracellular actin-containing microfilament bundles and less cell-surface fibronectin compared to normal cells. We have examined whether the loss of the anchorage requirement for growth is related to either of these structural changes in the cellular cytoskeleton. Our approach was to select a series of subclones from a nontransformed Syrian hamster fibroblast line, 8, for the acquisition of either anchorage independence in vitro or tumorigenicity in nude mice. These subclones were then examined for concomitant changes in the cytoskeletal structures. We found that anchorage independence, decreased actin cable organization, and tumorigenicity in nude mice were coordinately induced in both the in vitro- and in vivo-selected subclones, whereas the loss of fibronectin was not consistently co-induced with these three markers. These results suggest that the transformation-associated decrease in actin cable organization in this type of cell enhances the ability to grow without anchorage in vitro and to form tumors in vivo.
Sequence of centromere separation: lack of Colcemid effect on the Chinese hamster genome
Authors: Figueroa M.L. , Vig B.K.
Published: May 2008

This study describes the sequence of centromere separation in the Chinese hamster genome and the lack of any effect of Colcemid on this sequence. Analysis of bone marrow cells using sequential Giemsa staining and Q-banding established the sequence of centromere separation in cells derived from four Colcemid-treated and three untreated animals. Treatment of the data by use of the ANOVA test showed that the sequences established in the Colcemidtreated group did not differ from those in the untreated animals. The sequence of centromere separation in the Chinese hamster, as expressed by the pooled data from all seven animals, is chromosomes 1 and 2, followed by 3, 4, X, Y, 8, 9, 10, 5, 6, and 7.
The Morphology of Northern Hemisphere Blocking
Authors: Tyrlis E. , Hoskins B. J.
Published: May 2008

The morphology of regional blocking in the Northern Hemisphere is discussed using the 40-yr ECMWF Re-Analysis (ERA-40) dataset and a measure of blocking based on the reversal at storm-track latitudes of meridional θ contrasts on a potential vorticity (PV) surface representative of the tropopause. The focus is on cyclonic and anticyclonic Rossby wave breaking that is inherent to the blocking development, and the extent to which this is determined by the climatological jet position and the ambient shears. More generally, the importance of the climatological planetary scale is discussed. The approach is mainly through composite behavior, but informed by consideration of many individual events. A diversity of behavior is found with longitude in both winter and summer, and there is a striking reversal of the sense of the wave breaking between the two seasons that is generally consistent with the difference in the jet locations. Preferred behaviors are found in various regions and seasons, and retrogression of blocking is discussed.
High-Resolution Observations with MU Radar of a KH Instability Triggered by an Inertia–Gravity Wave in the Upper Part of a Jet Stream
Authors: Luce H. , Hassenpflug G. , Yamamoto M. , Fukao S. , Sato K.
Published: May 2008

Kelvin–Helmholtz (KH) instability is likely one of the most important sources of clear-air turbulence in the lower atmosphere. It produces billows, which mix and transport heat and materials vertically in the stably stratified atmosphere. Billows can also dissipate energy; therefore they can affect the larger-scale dynamics. While only a few direct observations have been reported in the tropopause region, in this work the authors report very detailed observations of billow structures around 16-km altitude, in the upper part of the jet stream. Observations were made with very high frequency (VHF)-band mid- and upper-atmosphere (MU) radar (Shigaraki, Japan; 34.85°N, 136.10°E) whose height resolution was improved with a range-imaging technique. KH billow structures were observed for at least 2 h and were found to have horizontal wavelengths of about 5.3 km and vertical extents between 0.5 and 1.0 km. Analysis of wind and temperature profiles measured by radiosondes launched from nearby meteorological stations indicated the presence of nearly monochromatic disturbances, likely due to a dominant inertia–gravity wave (IGW) superimposed on the background wind field. The presence of the IGW was also confirmed by analysis of wind profiles measured by the MU radar just before the KH billows were detected by the observations in range-imaging mode. The IGW, with vertical and horizontal wavelengths of about 3.5 and 600 km, respectively, may have been a direct radiation from the jet stream, as suggested by recent works, and likely played a major role in the onset of the observed KH instability.
Predictable Components and Singular Vectors
Authors: DelSole Timothy , Tippett Michael K.
Published: May 2008

This paper shows that if a measure of predictability is invariant to affine transformations and monotonically related to forecast uncertainty, then the component that maximizes this measure for normally distributed variables is independent of the detailed form of the measure. This result explains why different measures of predictability such as anomaly correlation, signal-to-noise ratio, predictive information, and the Mahalanobis error are each maximized by the same components. These components can be determined by applying principal component analysis to a transformed forecast ensemble, a procedure called predictable component analysis (PrCA). The resulting vectors define a complete set of components that can be ordered such that the first maximizes predictability, the second maximizes predictability subject to being uncorrelated of the first, and so on. The transformation in question, called the whitening transformation, can be interpreted as changing the norm in principal component analysis. The resulting norm renders noise variance analysis equivalent to signal variance analysis, whereas these two analyses lead to inconsistent results if other norms are chosen to define variance. Predictable components also can be determined by applying singular value decomposition to a whitened propagator in linear models. The whitening transformation is tantamount to changing the initial and final norms in the singular vector calculation. The norm for measuring forecast uncertainty has not appeared in prior predictability studies. Nevertheless, the norms that emerge from this framework have several attractive properties that make their use compelling. This framework generalizes singular vector methods to models with both stochastic forcing and initial condition error. These and other components of interest to predictability are illustrated with an empirical model for sea surface temperature.
Numerical Simulation of Mammatus
Authors: Kanak Katharine M. , Straka Jerry M. , Schultz David M.
Published: May 2008

Mammatus are hanging lobes on the underside of clouds. Although many different mechanisms have been proposed for their formation, none have been rigorously tested. In this study, three-dimensional numerical simulations of mammatus on a portion of a cumulonimbus cirruslike anvil are performed to explore some of the dynamic and microphysical factors that affect mammatus formation and evolution. Initial conditions for the simulations are derived from observed thermodynamic soundings. Five observed soundings are chosen—four were associated with visually observed mammatus and one was not. Initial microphysical conditions in the simulations are consistent with in situ observations of cumulonimbus anvil and mammatus. Mammatus form in the four model simulations initialized with the soundings for which mammatus were observed, whereas mammatus do not form in the model simulation initialized with the no-mammatus sounding. Characteristics of the modeled mammatus compare favorably to previously published mammatus observations.

Three hypothesized formation mechanisms for mammatus are tested: cloud-base detrainment instability, fallout of hydrometeors from cloud base, and sublimation of ice hydrometeors below cloud base. For the parameters considered, cloud-base detrainment instability is a necessary, but not sufficient, condition for mammatus formation. Mammatus can form without fallout, but not without sublimation. All the observed soundings for which mammatus were observed feature a dry-adiabatic subcloud layer of varying depth with low relative humidity, which supports the importance of sublimation to mammatus formation.
Structure and Formation of an Annular Hurricane Simulated in a Fully Compressible, Nonhydrostatic Model—TCM4*
Authors: Wang Yuqing
Published: May 2008

The structure and formation of an annular hurricane simulated in a fully compressible, nonhydrostatic tropical cyclone model—TCM4—are analyzed. The model is initialized with an axisymmetric vortex on an f plane in a quiescent environment, and thus the transition from the nonannular hurricane to the annular hurricane is attributed to the internal dynamics. The simulated annular hurricane has all characteristics of those recently documented by Knaff et al. from satellite observations: quasi-axisymmetric structure, large eye and wide eyewall, high intensity, and suppressed major spiral rainbands. A striking feature of the simulated annular hurricane is its large outward tilt of the wide eyewall, which is critical to the quasi-steady high intensity and is responsible for the maintenance of the large size of the eye and eyewall of the storm. Although the annular hurricane has a quasi-axisymmetric structure, marked low-wavenumber asymmetries exist in the eyewall region.

The formation of the simulated annular hurricane is found to be closely related to the interaction between the inner spiral rainbands and the eyewall convection. As the inner rainbands spiral cyclonically inward, they experience axisymmetrization due to strong shear deformation and filamentation outside the eyewall and evolve into a quasi-symmetric convective ring, which intensifies as it contracts while the eyewall breaks down and weakens. Eventually, the convective ring replaces the original eyewall. The new eyewall formed in such a way is wider and tilts more outward with height than the original eyewall. Several such eyewall cycles in our simulation produce an annular hurricane with large eyewall slope, large eye, and wide eyewall. The response of low-level winds to the tilted convective heating in the eyewall is an increase outside and a decrease inside the radius of maximum wind, prohibiting further contraction of the new eyewall. Strong convective mass flux in the eyewall updraft corresponds to strong convective overturning subsidence outside the eyewall, greatly suppressing the development of any major rainbands outside the eyewall. Although the eyewall cycle documented in this study contributes to the formation of annular hurricanes, it could be a general process causing the increase in eye size of real tropical cyclones as well.
Voices of Hope
Authors: Pearson Mildred M.
Published: May 2008

Using the self-efficacy literature as a theoretical framework, this article discusses the reality of academic achievement and academic performance among selected African American middle school girls. Both quantitative and qualitative research approaches are used to investigate the influence of self-efficacy. Thirty-seven African American middle school girls filled out an adversity questionnaire and also responded to the Children's Self-efficacy Survey. Based on the results, 10 girls were selected for in-depth interviews. Responses to interview questions reveal how these girls' self-efficacy helped them not only cope with obstacles in their lives but also excel academically. These responses provide important insights for educators who want to help this population of students continue to succeed.
Sources of Discontent
Authors: James Russell N. , Carswell Andrew T. , Sweaney Anne L.
Published: May 2008

This article presents the first systematic analysis of residential satisfaction ratings from the largest consumer comment Web site for U.S. apartment residents, www.ApartmentRatings.com. Using the 464,281 tenant satisfaction ratings posted from January 1, 2000, to January 1, 2007, we examine the relative importance of seven core factors in determining tenant satisfaction: parking, noise level, landscaping, safety, building construction, office staff, and maintenance service. Cross tabulation, ordered logit, probit, and path analysis models all point to tenant relations with management office staff as the most influential factor in tenant satisfaction. The fact that the manager—tenant relationship exists for tenants but not for homeowners may help to explain why the gap in residential satisfaction between owners and renters persists even when controlling for other physical environmental characteristics.
Adolescent Parenthood Through Educators' Eyes
Authors: Wright Patricia Ann , Davis Anita Ann
Published: May 2008

This study examines how educators in traditional and alternative public high school settings conceptualize the experiences of their pregnant and parenting students. Educators' narrative responses are qualitatively analyzed to identify their perceptions of students' worries and the types of support educators provide students. Results suggest that educators' perceptions and supportive actions, although not systematically related to variables of race or gender, are related to number of years of teaching experience and differences in school environment. Findings surrounding the ways in which educators make meaning of their students' experiences and serve as social support figures are discussed.
A Compliance Evaluation of the Transition Outcomes Project
Authors: Finn Jane E. , Kohler Paula D.
Published: May 2008

This study examines the quantitative results of an evaluation investigating implementation of the Transition Outcomes Project in a midwestern state. Data collection and analysis consist of preevaluation and postevaluation of students' Individualized Education Programs (IEPs) using the Transition Requirements Checklist and include statistical analyses to evaluate the concept of “compliance” as reflected in the IEP content. Findings indicated (a) an overall increase in the frequency of IEP transition items that meet Individuals With Disabilities Education Act requirements and (b) general improvement between expected and observed frequencies of the 32 items from initial to follow-up review. Patterns of change vary considerably. More than half of the items were “in compliance” at prereview and postreview while others remained missing, changed from missing to present, or from present to missing. This article raises questions about the complexity of evaluating such a model and the kinds of information states and school districts need to improve the content of IEPs.
“Getting Gut-Level”
Authors: McKim Allison
Published: May 2008

Using ethnographic data gathered at a mandated, community-based drug treatment program for women offenders, this article analyzes how gendered notions of the self and of autonomy shape penal governance. This study examines how psychological models of women's deviance, racialized visions of motherhood, and therapeutic techniques of the self come into tension with expectations of responsible, autonomous citizenship. The program prioritized therapeutic ways of governing its clients over those that emphasized economic self-reliance, rational decision making, and normalizing gender. This is because staff attributed criminal and addictive behaviors to women's inadequate self-understanding and lack of emotional autonomy in personal relations. Staff discouraged women's motherhood and paid labor because they saw these external obligations as a threat to women's autonomous selfhood. This research complicates claims that contemporary forms of penal treatment manage offenders through rational incentives and personal responsibility by pointing to the ways that subject formation is a gendered process.
The Effects of Nonprofit Accountability Ratings on Donor Behavior
Authors: Sloan Margaret F.
Published: May 2008

Although accountability systems are established to ensure organizational adherence to financial and ethical standards for nonprofit organizations, the reality of whether such standards make a difference to donors has not been measured. This article discusses the current landscape of accountability systems and accountability ratings and describes a model for estimating the effect of ratings systems on donor behavior within the theoretical context of information asymmetry. Hypotheses are tested with nonprofit ratings for New York charities from the Better Business Bureau's Wise Giving Alliance to estimate the effect of accountability ratings on the amount of contributions an organization receives. Results indicate that the Wise Giving Alliance “pass” ratings have a statistically significant effect on the contributions received; however, “did not pass” ratings are nonsignificant. The study is important for academics as well as practitioners who are monitoring time and money spent on accountability issues.
The Temporal Stability of the Effects Induced by the Cued Reaction Time Task
Authors: Versace Francesco , Mazzetti Michela , Codispoti Maurizio
Published: May 2008

The temporal stability of the effects induced by the Cued Reaction Time Task (CRTT) on the orienting of attention was assessed across four weekly sessions. Benefits, costs, and validity effects were computed for each session, and the correlation coefficients between each session were calculated (interindividual stability index). Intraindividual stability indices, the percentage of individuals showing both costs and benefits or the validity effect, were also calculated. The results (based on 41 participants) show a low stability for the effects in which the neutral trials were involved (benefits and costs) but an acceptable reliability for the validity effect, especially when evaluated using the intraindividual index. To maximize the reliability of the data collected using the CRTT, the validity effect seems to be a better probe of spatial orienting of attention.
Equivalence of a Measurement Model of Cognitive Abilities in U.S. Standardization and Australian Neuroscience Samples
Authors: Bowden Stephen C. , Weiss Lawrence G. , Holdnack James A. , Bardenhagen Fiona J. , Cook Mark J.
Published: May 2008

A psychological measurement model provides an explicit definition of (a) the theoretical and (b) the numerical relationships between observed scores and the latent variables that underlie the observed scores. Examination of the metric invariance of a measurement model involves testing the hypothesis that all components of the model relating observed scores to latent variables are equal across groups. The assumption of metric invariance is necessary for simple interpretation of scores. Establishing metric invariance also has implications for interpretation of convergent and divergent validity and patterns of deficit or disability. In this study the equivalence of the measurement model derived from the U.S. Wechsler Adult Intelligence Scale–III standardization sample was compared with a heterogeneous neurosciences sample in Australia. A pattern of strict metric invariance was observed across samples. These results provide evidence of the generality of the model underlying measurement of cognitive abilities.
The Validity and Utility of the Positive Presentation Management and Negative Presentation Management Scales for the Revised NEO Personality Inventory
Authors: Sellbom Martin , Bagby R. Michael
Published: May 2008

Schinka, Kinder, and Kremer developed “validity” scales for the Revised NEO Personality Inventory (NEO PI-R; Costa & McCrae) to detect underreporting—the Positive Presentation Management (PPM) Scale and overreporting—the Negative Presentation Management (NPM) Scale. In this investigation, the clinical utility of these scales was examined using the established validity scales from the Minnesota Multiphasic Personality Inventory–2 (MMPI-2; Butcher et al.) as the referent. The sample was composed of 370 psychiatric patients who completed the NEO PI-R and the MMPI-2 as part of a routine evaluation. Results indicated that response distortion compromised the utility of the NEO PI-R domain scales. Moreover, the PPM and NPM scales and an NPM–PPM index significantly differentiated invalid under-and overreporting groups from a valid responding group. The PPM and NPM–PPM index were adequate in classifying under- and overreporters, respectively.
Testing the Hierarchical Structure of the Children's Depression Inventory
Authors: García Luis F. , Aluja Anton , del Barrio Victoria
Published: May 2008

Using exploratory and confirmatory factor analyses, the aims were (a) to obtain, describe, and compare different solutions of three, five, and six first-order factors raised in the previous literature about the Children's Depression Inventory (CDI); (b) analyze the number and nature of the second-order factors; (c) test which model best reproduces the CDI structure; and (d) test possible developmental differences between child and adolescent samples. The CDI was applied to 4,707 Spanish children and adolescents with an age range between 7 and 16 years. Results show that best models considered five or six factors, including Social Problems (Anhedonia), Negative Affect, Externalizing, School Problems, and Negative Self-Esteem (Self-Deprecation). Also, a factor of Biological Dysregulation obtained some support. Higher-order factors do not reproduce the classical distinction between internalizing and externalizing symptoms. Finally, no large developmental differences in the CDI structure were found between children and adolescents samples.
An Overview of the Extra-Lipid Effects of Rosuvastatin
Authors: Kostapanos Michael S. , Milionis Haralampos J. , Elisaf Moses S.
Published: May 2008

Statins, in addition to their beneficial lipid modulation effects, exert a variety of several so-called “pleiotropic” actions that may result in clinical benefits. Rosuvastatin, the last agent of the class to be introduced, has proved remarkably potent in reducing low-density lipoprotein cholesterol levels. At present, no large-scale primary or secondary prevention clinical trials document either its long-term safety or its effectiveness in preventing cardiovascular events. A substantial number of experimental and clinical studies have indicate favorable effects of rosuvastatin on endothelial function, oxidized low-density lipoprotein, inflammation, plaque stability, vascular remodeling, hemostasis, cardiac muscle, and components of the nervous system. Available data regarding the effects of rosuvastatin on renal function and urine protein excretion do not seem to raise any safety concerns. Whether the established “pleiotropy” and/or lipid-lowering efficacy of rosuvastatin may translate into reduced morbidity and mortality remains to be shown in ongoing clinical outcome trials.
Quality of Life Among HIV-Infected Children in Thailand
Authors: Oberdorfer Peninnah , Louthrenoo Orawan , Puthanakit Thanyawee , Sirisanthana Virat , Sirisanthana Thira
Published: May 2008

The aim of the study was to measure quality of life in human immunodeficiency virus-infected children. This is a cross-sectional study among main caregivers of human immunodeficiency virus-infected children. The questionnaire consisted of 5 main domains: general health, physical functioning, symptoms, psychological well being, and social and role functioning. A total of 131 main caregivers (21% males, average age 42.5 years) of human immunodeficiency virus-infected children (28% male, average age 10.1 years) answered the questionnaires. Four out of 5 domains showed that children without immune suppression had a significantly higher quality of life than children with immune suppression. There was a significant correlation between health care utility and physical functioning, symptoms, and social and role functioning. The instrument had acceptable internal consistency and was a feasible measure of quality of life among human immunodeficiency virus-infected children. The information obtained will enable health care providers to establish comprehensive health care services to serve the needs of these children and their families.
Total and caspase-cleaved cytokeratin 18 in chronic cholecystitis: A prospective study
Authors: Simopoulos Constantinos , Tsaroucha Alexandra K , Asimakopoulos Byron , Giatromanolaki Alexandra , Gavriilidis Paschalis , Polychronidis Alexandros , Karayiannakis Anastasios
Published: May 2008

Background

Cell death mode has been studied in cancer, autoimmune, and neurodegenerative diseases. In this study, apoptosis and necrosis are investigated for the first time in patients with chronic calculous cholecystitis.

Methods and materials

Thirty five (35) patients (27 women and 8 men, aged 55.65 ± 13.48 years) with symptomatic chronic calculous cholecystitis underwent laparoscopic cholecystectomy. The early specific apoptotic tendency (caspase-cleaved cytokeratin 18) was studied in these patients with M30 Apoptosense ELISA and the total cytokerarin 18 (both derived from apoptosis and necrosis) with M65 ELISA. The ratio M30/M65 (caspase-cleaved to total cytokeratin 18) was also computed. According to the histopathological examination, the patients were divided in two groups: group A included patients with chronic inactive cholecystitis (n = 10), and group B those with chronic active cholecystitis (n = 25).

Results

The concentrations of caspase-cleaved cytokerarin 18 (CK18), and especially those of total CK18, were higher in bile samples than in serum samples. In group B, there were significant differences between serum and bile samples regarding both caspase-cleaved CK18 and total CK18. Cells staining positive for caspase-cleaved CK18 were present in the epithelial cells of the mucosa of the gallbladder.

Conclusion

CK18 is expressed in the gallbladder epithelial cells. The concentrations of both caspase-cleaved CK18 and total CK18 were higher in bile samples than in serum samples. The levels of total CK18, as well as caspase-cleaved CK18, do not seem to differ between active and inactive chronic cholecystitis.
Development and validation of psychosocial determinants measures of physical activity among Iranian adolescent girls
Authors: Pirasteh Ashraf , Hidarnia Alireza , Asghari Ali , Faghihzadeh Soghrate , Ghofranipour Fazlollah
Published: May 2008

Background

The present study aimed at assessing the psychometric properties of psychosocial determinants of physical activity-related measures in Iranian adolescent girls.

Methods

Several measures of psychosocial determinants of physical activity were translated from English into Persian using the back-translation technique. These translated measures were administered to 512 ninth and tenth-grade Iranian high school students.

Results

The results of a series of factor analysis showed that the self-efficacy scale contained a single factor, the social support scale contained two factors: family support and friend support, the physical activity 'pros & cons' scale contained two factors: physical activity pros scale and physical activity cons scale, the change strategies scale contained a single factor, the environment scale also contained a single factor. Chronbach's alphas, mean inter-item correlations and test-retest coefficients showed that these solutions were reliable.

Conclusions

These preliminary results provide support for using the mentioned scales to measure psychosocial determinants of physical activity in Iranian adolescent girls.
Police and public health partnerships: Evidence from the evaluation of Vancouver's supervised injection facility
Authors: DeBeck Kora , Wood Evan , Zhang Ruth , Tyndall Mark , Montaner Julio , Kerr Thomas
Published: May 2008

In various settings, drug market policing strategies have been found to have unintended negative effects on health service use among injection drug users (IDU). This has prompted calls for more effective coordination of policing and public health efforts. In Vancouver, Canada, a supervised injection facility (SIF) was established in 2003. We sought to determine if local police impacted utilization of the SIF. We used generalized estimating equations (GEE) to prospectively identify the prevalence and correlates of being referred by local police to Vancouver's SIF among IDU participating in the Scientific Evaluation of Supervised Injecting (SEOSI) cohort during the period of December 2003 to November 2005. Among 1090 SIF clients enrolled in SEOSI, 182 (16.7%) individuals reported having ever been referred to the SIF by local police. At baseline, 22 (2.0%) participants reported that they first learned of the SIF via police. In multivariate analyses, factors positively associated with being referred to the SIF by local police when injecting in public include: sex work (Adjusted Odds Ratio [AOR] = 1.80, 95%CI 1.28 – 2.53); daily cocaine injection (AOR = 1.54, 95%CI 1.14 – 2.08); and unsafe syringe disposal (AOR = 1.46, 95%CI 1.00 – 2.11). These findings indicate that local police are facilitating use of the SIF by IDU at high risk for various adverse health outcomes. We further found that police may be helping to address public order concerns by referring IDU who are more likely to discard used syringes in public spaces. Our study suggests that the SIF provides an opportunity to coordinate policing and public health efforts and thereby resolve some of the existing tensions between public order and health initiatives.
Extraction of elementary rate constants from global network analysis of E. coli central metabolism
Authors: Zhao Jiao , Ridgway Douglas , Broderick Gordon , Kovalenko Andriy , Ellison Michael
Published: May 2008

Background

As computational performance steadily increases, so does interest in extending one-particle-per-molecule models to larger physiological problems. Such models however require elementary rate constants to calculate time-dependent rate coefficients under physiological conditions. Unfortunately, even when in vivo kinetic data is available, it is often in the form of aggregated rate laws (ARL) that do not specify the required elementary rate constants corresponding to mass-action rate laws (MRL). There is therefore a need to develop a method which is capable of automatically transforming ARL kinetic information into more detailed MRL rate constants.

Results

By incorporating proteomic data related to enzyme abundance into an MRL modelling framework, here we present an efficient method operating at a global network level for extracting elementary rate constants from experiment-based aggregated rate law (ARL) models. The method combines two techniques that can be used to overcome the difficult properties in parameterization. The first, a hybrid MRL/ARL modelling technique, is used to divide the parameter estimation problem into sub-problems, so that the parameters of the mass action rate laws for each enzyme are estimated in separate steps. This reduces the number of parameters that have to be optimized simultaneously. The second, a hybrid algebraic-numerical simulation and optimization approach, is used to render some rate constants identifiable, as well as to greatly narrow the bounds of the other rate constants that remain unidentifiable. This is done by incorporating equality constraints derived from the King-Altman and Cleland method into the simulated annealing algorithm. We apply these two techniques to estimate the rate constants of a model of E. coli glycolytic pathways. The simulation and statistical results show that our innovative method performs well in dealing with the issues of high computation cost, stiffness, local minima and uncertainty inherent with large-scale non-convex nonlinear MRL models.

Conclusion

In short, this new hybrid method can ensure the proper solution of a challenging parameter estimation problem of nonlinear dynamic MRL systems, while keeping the computational effort reasonable. Moreover, the work provides us with some optimism that physiological models at the particle scale can be rooted on a firm foundation of parameters generated in the macroscopic regime on an experimental basis. Thus, the proposed method should have applications to multi-scale modelling of the real biological systems allowing for enzyme intermediates, stochastic and spatial effects inside a cell.
Metabolic regulation analysis of an ethanologenic Escherichia coli strain based on RT-PCR and enzymatic activities
Authors: Orencio-Trejo Montserrat , Flores Noemí , Escalante Adelfo , Hernández-Chávez Georgina , Bolívar Francisco , Gosset Guillermo , Martinez Alfredo
Published: May 2008

Background

A metabolic regulation study was performed, based upon measurements of enzymatic activities, fermentation performance, and RT-PCR analysis of pathways related to central carbon metabolism, in an ethanologenic Escherichia coli strain (CCE14) derived from lineage C. In comparison with previous engineered strains, this E coli derivative has a higher ethanol production rate in mineral medium, as a result of the elevated heterologous expression of the chromosomally integrated genes encoding PDC
Zm
and ADH
Zm
(pyruvate decarboxylase and alcohol dehydrogenase from Zymomonas mobilis). It is suggested that this behavior might be due to lineage differences between E. coli W and C.

Results

This study demonstrated that the glycolytic flux is controlled, in this case, by reactions outside glycolysis, i.e., the fermentative pathways. Changes in ethanol production rate in this ethanologenic strain result in low organic acid production rates, and high glycolytic and ethanologenic fluxes, that correlate with enhanced transcription and enzymatic activity levels of PDC
Zm
and ADH
Zm
. Furthermore, a higher ethanol yield (90% of the theoretical) in glucose-mineral media was obtained with CCE14 in comparison with previous engineered E. coli strains, such as KO11, that produces a 70% yield under the same conditions.

Conclusion

Results suggest that a higher ethanol formation rate, caused by ahigher PDC
Zm
and ADH
Zm
activities induces a metabolic state that cells compensate through enhanced glucose transport, ATP synthesis, and NAD-NADH+H turnover rates. These results show that glycolytic enzymatic activities, present in E. coli W and C under fermentative conditions, are sufficient to contend with increases in glucose consumption and product formation rates.