bluuebunny/crossref_metadata_2025 huggingface dataset:
A new strategy for assessing selenoprotein function: siRNA knockdown/knock-in targeting the 3′-UTR
Authors: Yoo Min-Hyuk , Xu Xue-Ming , Turanov Anton A. , Carlson Bradley A. , Gladyshev Vadim N. , Hatfield Dolph L.
Published: April 2007

Selenocysteine insertion into protein in mammalian cells requires RNA elements in the 3′-untranslated regions (3′-UTRs) of selenoprotein genes. The occurrence of these conserved sequences should make selenoproteins particularly amenable for knockdown/knock-in strategies to examine selenoprotein functions. Herein, we utilized the 3′-UTR of various selenoproteins to knock down their expression using siRNAs and then knock in expression using constructs containing mutations within the target region. Thioredoxin reductase 1 (TR1) knockdown in a mouse kidney cell line resulted in the cells growing about 10% more slowly, being more sensitive to UV radiation, and having increased apoptosis in response to UV than control cells. The knockdown cells transfected with a construct encoding the wild-type TR1 gene and having mutations in the sequences targeted by siRNA restored TR1 expression and catalytic activity, rendered the knockdown cells less sensitive to UV, and protected the cells against apoptosis. We also applied this technique to other selenoproteins, selenophosphate synthetase 2 and glutathione peroxidase 1, and found that mRNA and protein levels were restored following transfection of knockdown cells with the corresponding knock-in constructs. In addition to important new insights into the functions of key mammalian selenoproteins, the data suggest that the RNAi-based knock-in technology could distinguish phenotypes due to off-targeting and provide a new method for examining many of the subtleties of selenoprotein function not available using RNAi technology alone.
Thermodynamics of organic cation exchange selectivity in smectites
Authors: Teppen Brian J. , Aggarwal Vaneet
Published: April 2007

The selectivities of clay minerals for larger organic cations over smaller ones have been attributed to favorable clay-organic interactions in clay interlayers and to hydrophobic effects resulting from (partial) dehydration of organic cations in the clay interlayers, but the magnitudes of these energy components have not been estimated. The objective of this study was to differentiate and quantify the contributions of clay-phase and aqueous-phase energy changes to the overall thermodynamics of cation exchange, and thereby to determine which forces control the general selectivity of smectites for organic cations. We compiled literature measurements and estimates for the free energies of overall cation exchange reactions and also for the free energies of organic cation hydration. Our study suggests that organic cation-exchange thermodynamics can be broken into three classes: (1) For two organic cations with identical head-groups, the difference in their cation exchange selectivities is driven almost quantitatively by the difference in their free energies of hydration. Here, the mechanism for organic cation selectivity is almost pure hydrophobic expulsion of the larger cation from water. The clay interlayer simply behaves like a subaqueous phase into which the least hydrophilic organic cations partition and the essentials of such cation exchange selectivity can be explained without any favorable clay-organic interactions. (2) For two organic cations with rather different head-groups, the difference in their cation exchange selectivities is just a small percentage of the difference in their free energies of hydration. This indicates that the clay phase interacts much more strongly with the cation having the smaller head-group, as might be expected on the basis of simple electrostatics. Here, the clay has an intrinsic strong preference for the cation with smaller head-group yet ‘selects’ for the cation with larger head-group because the aqueous-phase preference for the cation with smaller head-group is even stronger than the clay preference. (3) When the clay is already substantially loaded with organic cations, then van der Waals forces apparently can play a significant role in determining organic cation exchange selectivity differences.
HDTMA in the interlayers of high-charged Llano vermiculite
Authors: Slade Phil G. , Gates Will P.
Published: April 2007

X-ray diffraction shows that ordered interlayer structures form when high-charged Llano vermiculite is reacted with HDTMA-Br or HDTMA-acetate, but the structures differ from those given by low-charged vermiculites. The differences arise in two ways; firstly when both HDTMA+ cations and HDTMA-Br (or -acetate) ion pairs are present as interlayer guest species, a superstructure forms which is less commensurate with the host structure of high-charge vermiculite than it is for lower-charged material. Secondly, although a commensurate 3a × b interlayer superstructure forms when HDTMA+ cations are the only interlayer guests, an increasing number of charge-balancing cations must be accommodated as the layer charge increases. This results in some structural disorder which is only observed in the diffraction pattern of HDTMA+-intercalated, high-charge vermiculite. Organic ion pairs tend to order along widely spaced rows corresponding to the intersections of two sets of scattering planes. For the acetate form, one set of planes has spacings of 3.52 Å, but for the bromide form the value is 3.67 Å. Scattering planes in the second set have spacings of 4.02 Å, independently of counter-anion size. These two sets of planes diverge from one another by ∼10°. Ordering is more apparent in the presence of acetate anions than it is for the smaller Br− anions. In the high-charged intercalates, from which organic ion pairs have been removed, HDTMA+ cations occupy positions on a centered two-dimensional superlattice and also randomly, some interstitial positions as necessitated by layer charge.
Lamellar nanostructure in ‘Somasif’-based organoclays
Authors: Gelfer Mikhail Y. , Burger Christian , Nawani Pranav , Hsiao Benjamin S. , Chu Benjamin , Si Mayu , Rafailovich Miriam , Panek Grazyna , Jeschke Gunnar , Fadeev Alexander Y. , Gilman Jeffrey W.
Published: April 2007

Thermally induced lamellar structure changes due to phase transition and degradation in organoclays based on a synthetic ‘Somasif’ mineral and two organic surfactants, di-methyl dihydro-ditallow ammonia chloride (DMDTA) and tri-butyl-hexadecyl phosphonium bromide (HTBP) were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, in situ simultaneous small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) over the temperature range 30–280°C. Results indicated that the surfactant layer in ‘Somasif’-based organoclays underwent thermally induced melting-like order-disorder transition followed by desorption of surfactant molecules, resulting in drastic changes in the character of the layer periodicity. The transition temperature (Ttr), determined from the endothermic transition in DSC, was found to depend strongly on the type and the content of surfactant incorporated. Temperature-resolved SAXS indicated complex intercalated layered structures, containing multiple lamellar stack populations of two different organic layer thicknesses. A weak scattering peak (s0), located at exactly the half angular position of the strong first scattering maximum s1 (s0 = 0.5s1), was found in all tested ‘Somasif’ clays. The presence of this peak can be attributed to a slight breaking of the translational symmetry in the layered structure, causing the 1D repeat period in real space to be doubled. In other words, some portions of layers are grouped into pairs and a single pair forms the new repeat unit. This arrangement is reminiscent of the Peierls-like distortion.
Silicic acid magadiite as a host for n-alkyldiamine guest molecules and features related to the thermodynamics of intercalation
Authors: Macedo Thaís R. , Petrucelli Giovanni C. , Airoldi Claudio
Published: April 2007

Somen-alkyldiamines with thegeneral formulae H2N(CH2)nNH2 (n = 2–5) were intercalated into the layered silicic acid magadiite, from aqueous solution, causing an increase in the original interlayer distance of 1172 pm. The synthetic magadiite and all intercalated compounds were characterized by elemental analysis, infrared vibrational spectroscopy, X-ray diffractometry, 29Si nuclear magnetic resonance in the solid state, thermogravimetry, scanning electron microscopy, surface area and porosity. The intercalation was followed through a batch-wise method at 298±1 K and gave the maximum amounts 3.70, 2.80, 1.75 and 1.18 mmol g−1, for n varying from 2 to 5, respectively. The well characterized magadiite was calorimetrically titrated in a heterogeneous medium, to obtain the thermodynamic data of intercalation at the solid/liquid interface. Linear correlations were obtained for the number of moles intercalated (Nf), th einterlamellar distance (d) and the specific enthalpy (Δinth) values of the interactive process as a function of the number of C atoms of the aliphatic organic chains (nC) for n-alkyldiamine: Nf = (5.36±0.25) − (0.86±0.07)nC, d = (1406.6±1.9) + (20.9±0.5)nC and Δinth = (5.96±0.25) + (0.06±0.01)nC. The basic N guest atom/silanol acidic center interactions inside the host nanospace gallery gave exothermic enthalpies, positive entropies and negative Gibbs free energy values. This set of data suggests the spontaneity of these intercalation reactions.
Does water swell the ordered domains in polyelectrolyte/clay multilayers?
Authors: Rouse Jason H. , Ferguson Gregory S.
Published: April 2007

X-ray diffraction has been used to study the sorption of water by multilayer films containing ordered stacks of alternating layers of an organic polyelectrolyte and individual platelets of a smectite. The position and shape of the 001 reflections due to the ordered polyelectrolyte/platelet stacks were essentially the same when in air at low relative humidity (23–25% RH) and under water. These data indicate that swelling occurs exclusively in X-ray amorphous regions within the film, and that the ordered polyelectrolyte/clay domains themselves are not ‘swellable’ by water.
Fe(III)-modified montmorillonite and bentonite: Synthesis, chemical and UV-VIs spectral characterization, arsenic sorption, and catalysis of oxidative dehydrogenation of propane
Authors: Grygar T. , Hradil D. , Bezdička P. , Doušová B. , Čapek L. , Schneeweiss O.
Published: April 2007

Two major species were identified in Fe-treated montmorillonite: monomeric or dimeric hydroxoaqua cations <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:c="http://cambridge.org/core/content" xmlns:core="http://cambridge.org/core" xmlns:m="http://cambridge.org/core/metadata" xmlns:cup="http://contentservices.cambridge.org" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:mnf="http://cambridge.org/core/manifest">Fe(OH)x(3−x)+${\rm{Fe}}({\rm{OH}})_x^{(3 - x) + }$ (form I), and polymeric structures with edge-shared Fe(O,OH)6 (form II). These species have different electron spectra (absorption maximum is 29,600 cm−1 in form I, and 26,000 and 28,000 cm−1 in form II), chemical and thermal stability, and electrochemical behavior. Form I behaves as a partly exchangeable cation in interaction with Cu2+ from Cu-trien solution and Ni2+ from Ni-EDTA, that can be used for selective quantitative analysis. On heating above the dehydration temperature (∼100–150°C) montmorillonite with Fe3+ in form I is converted to a mica-like structure and Fe3+ ions are fixed more strongly in the montmorillonite structure. Form II behaves similarly to hydrous ferric oxides, but its thermal crystallization to hematite is postponed to ∼500–600°C. The Fe3+ cations in the interlayer space are much less thermally stable than Al pillars in pillared interlayered clays (PILCs). Form I is more active in oxidative dehydrogenation of propane, while form II is the active species in sorption of As and the non-specific combustion of propane. To produce only form II by the treatment of montmorillonite with Fe3+, its load must be kept below ∼20 wt.%; otherwise the usual hydrous ferric oxides are formed.
Altered volcanic ash as an indicator of marine environment, reflecting pH and sedimentation rate — Example from the Ordovician Kinnekulle bed of Baltoscandia
Authors: Kiipli Tarmo , Kiipli Enli , Kallaste Toivo , Hints Rutt , Somelar Peeter , Kirsimäe Kalle
Published: April 2007

The composition of altered volcanic ash of the Late Ordovician Kinnekulle bed was studied in geological sections of the Baltic Paleobasin. The composition of altered ash varies with paleosea depth from northern Estonia to Lithuania. The ash bed in shallow shelf limestones contains an association of illite-smectite (I-S) and K-feldspar, with the K2O content ranging from 7.5 to 15.3%. The limestone in the transition zone between shallow- and deep-shelf environments contains I-S-dominated ash with K2O content from 6.0 to 7.5%. In the deep-shelf marlstone and shale, the volcanic ash bed consists of I-S and kaolinite with a K2O content ranging from 4.1 to 6.0%. This shows that authigenic silicates from volcanic ash were formed during the early sedimentary-diagenetic processes. The composition of the altered volcanic ash can be used as a paleoenvironmental indicator showing the pH of the seawater or porewater in sediments as well as the sedimentation rate.
Role of smectite in siliceous-sinter formation and microbial-texture preservation: Octopus Spring, Yellowstone National Park, Wyoming, USA
Authors: Kyle Jennifer E. , Schroeder Paul A.
Published: April 2007

A siliceous sinter collected from Octopus Spring in Yellowstone National Park, USA contains an occluded volcanic rock fragment that has undergone alteration. The sinter piece beyond the fragment is mostly dominated by opal-A with trace amounts of bacterial cells, calcite and detrital quartz. Within the altered rock region, the mineral assemblage is dominated by dioctahedral smectite and quartz with trace amounts of pseudobrookite, ilmenite, rutile and hematite. Onset of opal-CT formation was only found in the outer spicular region of the sinter, which is unexpected given that this outer part represents newest growth. A reaction mechanism is proposed whereby the alteration of feldspar to smectitic clay locally produces excess silica, and alkali metal, and raises pH. As the clay mineral forms, it sequesters ions from pore fluids thereby inhibiting the opal-A phase change to more ordered opal-CT. Ions such as Mg are known to promote the opal-A to opal-CT reaction. Smectite formation therefore may assist microbial-texture preservation processes as excess silica produced increases the rate at which primary opal-A is formed. The altered zone also retains the greatest amount of fixed C and fixed N (operationally defined as C and N retained upon combustion at 450°C). The fixed N probably represents ammonium trapped in the exchangeable interlayer site of the smectite. This fixed N may serve as a potential biological signature of microbial activity in ancient rocks formed in similar environments.
Short-term hydrothermal effects on the ‘crystallinities’ of illite and chlorite in the footwall of the Aachen-Faille du Midi thrust fault — First results of the RWTH-1 drilling project
Authors: Sindern Sven , Stanjek Helge , Hilgers Christoph , Etoundi Yvonne
Published: April 2007

Investigation of material from three core sections of the RWTH-1 drill-hole in the Wurm syncline of Aachen, Germany, shows mineralogical and structural evidence of intensive hydrothermal activity in the footwall of the Aachen thrust. Mineral and microstructural data indicate minimum temperatures of 200–250°C. CISillite 001 values of 0.45–0.61 (Δ°2θ) and insignificant amounts of smectite indicate a late diagenetic grade for illite pointing to temperatures <200°C. Chlorite, mainly formed in veins and cleavage planes, has CISchlorite 002 values between 0.35 and 0.26 (Δ°2θ) which only in part point to anchizonal grade. In contrast to these illite and chlorite data, maximum temperatures up to 370°C can be expected based on comparison with recently published fluid inclusion and mineral thermometric data. Illite is neither significantly affected by the hydrothermal event nor by deformation, and mirrors the burial history of the Wurm syncline.

Chlorite grew syntectonically as is shown by bent and predominantly stretched sheets which do not, however, have deformed structures. Syntectonic hydrothermal growth by incipient nucleation along crystal edges limited domainsize and thus also the CISchlorite 002 values. The hydrothermal event did not last long enough to allow further crystal growth. The retarded CISillite and CISchlorite grades can be best explained by limited duration(probably <5000 y) of the hydrothermal event which for a short time reached epithermal temperatures. The hydrothermal fluid flow was caused by dewatering of sedimentary rocks during thrusting and tectonic thickening within the Variscan orogen and it was focused along the Aachen thrust which represents the frontal Variscan thrust.
Novel method for transmission infrared analysis of clay minerals using silicon wafer substrates
Authors: Caulfield Jeffrey A. , Wells Todd A. , Miller Keith E.
Published: April 2007

A novel method for the analysis of clay minerals using Fourier transform infrared spectroscopy is presented. Clay mineral suspensions are dried on a Si wafer substrate for transmission infrared (IR) analysis. Four natural Source Clays from the Source Clays Repository of The Clay Minerals Society, SWy-2, SAz-1, SHCa-1 and KGa-1b, as well as the synthetic hectorite, Laponite RD, were analyzed using the described method with signal to noise (s/n) ratios in excess of 100,000 for the strongly absorbing Si-O stretching frequency. Scanning electron microscopy (SEM) images show that the mineral films possess suitable uniformity and low surface roughness for transmission IR measurements that is confirmed by minimal deviations in the baseline of collected IR spectra. The IR spectra are generated and peak locations are compared to previously reported values, generated from KBr pellet and attenuated total reflectance methods.
Ab initio calculations of relative stabilities of different structural arrangements in dioctahedral phyllosilicates
Authors: Tunega Daniel , Goodman Bernard A. , Haberhauer Georg , Reichenauer Thomas G. , Gerzabek Martin H. , Lischka Hans
Published: April 2007

An ab initio theoretical approach has been used to calculate optimized geometries and the relative energies of various compositional arrangements in structures of dioctahedral smectites based on models consisting of two unit-cells. These calculations indicate that the energy differences between structures having vacancies in sites with cis- or trans-OH coordination are small and that their relative energies vary with the chemical nature of the substitutions. For example, a cis-OH coordination for the vacancy was the most stable when the interlayer charge originated from substitution of Al for Si in the tetrahedral sheet, whereas the trans-coordination was the more stable for most cases of substitution in the octahedral sheet, an exception being Fe(II) for Al where the cis-OH coordination was favored. It seems likely, therefore, that long-range structural disorder will be a common phenomenon in natural phyllosilicate specimens.
Book Reviews
Authors: Hartas Dimitra
Published: April 2007

The linguistics, neurology and politics of phonics: Silent e speaks out
Book Reviews
Authors: Psaltis C.
Published: April 2007

Social research methods
Book Reviews
Authors: Bray Alison
Published: April 2007

Gifted children – a guide for parents and professionals
Book Reviews
Authors: Strand Steve
Published: April 2007

Statistics for research: With a guide to SPSS (2nd ed.)
How Reliable Is a Negative Blood Culture Result? Volume of Blood Submitted for Culture in Routine Practice in a Children's Hospital
Authors: Connell Thomas G. , Rele Mhisti , Cowley Donna , Buttery Jim P. , Curtis Nigel
Published: May 2007

OBJECTIVES. The primary aims of this study were to determine the volume of blood submitted for culture in routine clinical practice and to establish the proportion of blood cultures with a blood volume inadequate for reliable detection of bacteremia.

METHODS. The volumes of blood samples submitted for culture from infants and children up to 18 years of age were measured over a 6-month period. Blood cultures were deemed adequate submissions if they contained an appropriate (age-related) volume of blood and were submitted in the correct blood culture bottle type. During the study, an educational intervention designed to increase the proportion of adequate blood culture submissions was undertaken.

RESULTS. The volume of blood submitted in 1358 blood culture bottles from 783 patients was analyzed. Of the 1067 preintervention blood cultures, 491 (46.0%) contained an adequate blood volume and only 378 (35.4%) were adequate submissions on the basis of collection into the correct blood culture bottle type. After the intervention, there were significant increases in both the proportion of blood cultures containing an adequate blood volume (186 [63.9%] of 291 cultures) and the proportion of adequate submissions (149 [51.2%] of 291 cultures). Overall, blood cultures with an adequate blood volume were more likely than those with an inadequate blood volume to yield positive blood culture results (34 [5.2%] of 655 cultures vs 14 [2.1%] of 648 cultures). Similarly, adequate blood culture submissions were more likely than inadequate submissions to yield positive blood culture results (26 [5.1%] of 506 cultures vs 22 [2.8%] of 797 cultures).

CONCLUSIONS. In routine clinical practice, a negative blood culture result is almost inevitable for a large proportion of blood cultures because of the submission of an inadequate volume of blood. Even after an educational intervention, nearly one half of blood cultures were inadequate submissions.
Digital Childhood: Electronic Media and Technology Use Among Infants, Toddlers, and Preschoolers
Authors: Vandewater Elizabeth A. , Rideout Victoria J. , Wartella Ellen A. , Huang Xuan , Lee June H. , Shim Mi-suk
Published: May 2007

OBJECTIVES. The objectives of this study were to describe media access and use among US children aged 0 to 6, to assess how many young children fall within the American Academy of Pediatrics media-use guidelines, to identify demographic and family factors predicting American Academy of Pediatrics media-use guideline adherence, and to assess the relation of guideline adherence to reading and playing outdoors.

METHODS. Data from a representative sample of parents of children aged 0 to 6 (N = 1051) in 2005 were used. Descriptive analyses, logistic regression, and multivariate analyses of covariance were used as appropriate.

RESULTS. On a typical day, 75% of children watched television and 32% watched videos/DVDs, for approximately 1 hour and 20 minutes, on average. New media are also making inroads with young children: 27% of 5- to 6-year-olds used a computer (for 50 minutes on average) on a typical day. Many young children (one fifth of 0- to 2-year-olds and more than one third of 3- to 6-year-olds) also have a television in their bedroom. The most common reason given was that it frees up other televisions in the house so that other family members can watch their own shows (54%). The majority of children aged 3 to 6 fell within the American Academy of Pediatrics guidelines, but 70% of 0- to 2-year-olds did not.

CONCLUSIONS. This study is the first to provide comprehensive information regarding the extent of media use among young children in the United States. These children are growing up in a media-saturated environment with almost universal access to television, and a striking number have a television in their bedroom. Media and technology are here to stay and are virtually guaranteed to play an ever-increasing role in daily life, even among the very young. Additional research on their developmental impact is crucial to public health.
Therapeutic Drug Monitoring for Caffeine in Preterm Neonates: An Unnecessary Exercise?
Authors: Natarajan Girija , Botica Mirjana-Lulic , Thomas Ronald , Aranda Jacob V.
Published: May 2007

OBJECTIVE. Our goal was to determine the value of measuring plasma caffeine levels in preterm neonates treated with caffeine for apnea. We evaluated plasma concentrations of caffeine attained in preterm neonates at standard doses, at varying postconceptual ages, with renal or hepatic dysfunction and when there was clinical lack of efficacy. We hypothesized that measurement of plasma caffeine concentrations during apnea therapy is not clinically helpful.

PATIENTS/METHODS. An observational study was conducted at Hutzel Women's Hospital between January 2000 and September 2005. Preterm neonates who were being treated with caffeine and who had a plasma caffeine level measured on at least 1 occasion were included.

RESULTS. A total of 231 caffeine blood levels were obtained from 101 preterm neonates with a median gestation of 28 weeks (range: 23–32 weeks) and birth weight of 1030 g (range: 540–2150 g). The caffeine citrate dose used ranged form 2.5 to 10.9 mg/kg (median: 5 mg/kg), and the levels ranged from 3.0 to 23.8 mg/L. Levels were between 5.1 and 20 mg/L in 94.8%, <5 mg/L in 2.1%, and >20 mg/L in 3.1%. Levels in the 5.1 to 20 mg/L range were attained on 91.3% of occasions when there was concomitant renal dysfunction (n = 23) and in all cases of hepatic dysfunction (n = 13). The median (25th, 75th quartiles) levels drawn for lack of efficacy (14.1 [10.2, 8.3] mg/L; n = 94) were comparable to those obtained for routine monitoring (13.7 [11, 9] mg/L; n = 107).

CONCLUSIONS. A majority of preterm neonates attain plasma caffeine levels between 5 and 20 mg/L, independent of gestation. This observation held even for the small number of subjects with elevated blood urea nitrogen, serum creatinine, or liver enzyme levels. Therapeutic drug monitoring is not necessary when caffeine is used for the treatment of apnea of prematurity in neonates.
An indirect flow cytometric test for detection of anti-neutrophil antibodies in dogs
Authors: Weiss Douglas J.
Published: May 2007

Objective—To develop a clinically applicable assay for detection of serum anti-neutrophil antibodies in dogs.

Sample Population—Serum samples of 20 healthy dogs and 20 sick dogs.

Procedures—An indirect immunofluorescence assay was developed in which canine serum was incubated with paraformaldehyde-fixed neutrophils and subsequently incubated with fluorescein-conjugated rabbit anti-dog IgG. Neutrophil median fluorescence intensity and the percentage of neutrophils with an increase in fluorescence intensity were determined by use of a flow cytometer.

Results—Neutrophils incubated with serum from healthy and sick dogs had a normally distributed curve when displayed as a histogram. Alloantibodies or immune complexes that significantly affected test results were not detected. Hyperglobulinemia did not appear to affect test results. The neutrophil donor did not significantly affect test results. With 1 exception, results for the sick dogs did not differ appreciably from those for healthy dogs. Serum from a dog with steroid-responsive neutropenia had a greater neutrophil fluorescence value and percentage of neutrophils with an increase in fluorescence intensity, compared with either healthy or sick dogs.

Conclusions and Clinical Relevance—The indirect immunofluorescence test gave consistent results for healthy and sick dogs and detected anti-neutrophil antibodies in a dog with steroid-responsive neutropenia. Definitive evaluation of the test will be dependent on evaluation of persistently neutropenic dogs and correlation of test results with a response to immunosuppressive therapy.
Early fetal sexing of Saanen goats by use of transrectal ultrasonography to identify the genital tubercle and external genitalia
Authors: Santos Maico Henrique Barbosa , Moraes Érica Paes Barreto Xavier , Bezerra Filipe Queirós Gondim , Moura Roseana Tereza Diniz , Paula-Lopes Fabiola , Neves Jairo Pereira , Lima Paulo Fernandes , Oliveira Marcos Antonio Lemos
Published: May 2007

Objective—To define the optimum period for sexing of Saanen goat fetuses by use of transrectal ultrasonography.

Animals—82 Saanen goats pregnant with 124 fetuses.

Procedures—Fetal sexing was performed on the basis of the final location of the genital tubercle or identification of external genitalia. In experiment 1, fetuses (n = 78) were monitored every 48 hours from days 40 to 60 of gestation, whereas for experiment 2, 46 fetuses were examined only once between days 47 and 77 of gestation.

Results—For experiment 1, accuracy of fetal sexing was 20 of 20 (100%) for a single fetus, 39 of 42 (92.8%) for twin fetuses, and 10 of 16 (62.5%) for triplet fetuses. Diagnostic accuracy was significantly lower for triplet fetuses than that for single or twin fetuses. Final location of the genital tubercle was detected between 45 and 55 days of gestation (mean ± SEM, 48.9 ± 1.8 days). For experiment 2, accuracy of fetal sexing for a single fetus (24/24 [100%]) was significantly higher than the accuracy for twin fetuses (16/22 [72.7%]). Considering all fetuses that were born, accuracy of diagnosis was 69 of 78 (88.4%) for experiment 1 and 40 of 46 (86.9%) for experiment 2. Accuracy did not differ significantly between experiments.

Conclusions and Clinical Relevance—Real-time ultrasonography after day 55 of gestation is a suitable method for determination of sex of Saanen goat fetuses by observation of the genital tubercle or identification of external genitalia.
Knowledge and Nature: History as the Teacher of Life Revisited
Authors: Schäfer Wolf
Published: April 2007

This contribution revisits the dictum "history is the teacher of life" (historia magistra vitae) and shows that modern knowledge-societies are beginning to use their growing information about natural and human history to address present-day problems. Starting with Leopold von Ranke's refusal to investigate history for the benefit of learning from it, the essay cites two contemporary attempts at extracting useful knowledge from history: "real-world experiments" and "natural experiments." Wolfgang Krohn developed the former with collaborators in Bielefeld and Jared Diamond features the latter.
The Lessons of Katrina for Intelligent Public Decision Making
Authors: Woodhouse Edward J.
Published: April 2007

Was the Hurricane Katrina disaster an aberration, or did it emerge from decision-making processes similar to those governing other public outcomes? Is it more reasonable to expect post-disaster analyses to lead to systematic learning and improved policy, or not to change very much? Most generally, what can be learned about appropriate expertise and usable knowledge from the Katrina experience? I argue that many of the same processes and institutions are at work to create vulnerable populations, design the built environment carelessly with respect to public values, place barriers in the way of preventive action, and make it difficult for experts to contribute to improved outcomes. No doubt there will be some hurricane-specific learning in Katrina's wake, such as more houses on stilts, but political influentials are unlikely to revamp the systemic norms, practices, and institutions that helped shape the disaster. Implications are discussed for interdisciplinary, problem-focused research and community service by scientists, engineers, and other experts.
Using Metaphors in Restoring Nature
Authors: Keulartz Jozef
Published: April 2007

There has recently been growing interest in the role of metaphors in environmentalism and nature conservation. Metaphors not only structure how we perceive and think but also how we should act. The metaphor of nature as a book provokes a different attitude and kind of nature management than the metaphor of nature as a machine, an organism, or a network. This article explores four clusters of metaphors that are frequently used in framing ecological restoration: metaphors from the domains of engineering and cybernetics; art and aesthetics; medicine and health care; and geography. The article argues that these metaphors, like all metaphors, are restricted in range and relevance, and that we should adopt a multiple vision on metaphor. The adoption and development of such a multiple vision will facilitate communication and cooperation across the boundaries that separate different kinds of nature management and groups of experts and other stakeholders.
Environment, Development, and the Global Perspective: From Critical Security to Critical Globalization
Authors: Kütting Gabriela
Published: April 2007

This article reviews the contributions of the two main discourses that study the environment and development in global politics: the human/environmental security discourse and the critical globalization discourse. Both sub-disciplines deal with what is substantively the same subject matter from different perspectives. However, there is hardly any cross-reference between these two dialogues. This article explores the contributions of these two bodies of literature and evaluates their common ground. It argues that with the exception of the traditional environmental security school of thought there is substantial overlap in terms of research concerns. However, it also finds that the language of the critical human/ecological security school of thought hinders rather than helps its research concern.
The Power of Nature and the Nature of Power: How Agrarian Myths Become Reality
Authors: Weiland Sabine
Published: April 2007

The bovine spongiform encephalopathy (BSE) crisis challenged one of the basis principles of modernity: the divide between nature and society. In a case study on the German agricultural sector, I analyze how the societal actors responded in order to cope with the crisis. In their attempt to re-establish the division between nature and society, they employed the ambivalences of this relationship for strategic purposes. The actors sought to relocate or to newly define the boundary in line with their own ideas and interests. It can be seen how "nature" was frequently used as legitimizing ground in the narratives. The analysis of the politics of nature aims to add a process dimension to Latourian diagnosis of the eroding nature-society divide.
Climates of Change: Perspectives on Past and Future Climate Change and its Impact on Human Societies
Authors: Rosen Arlene M.
Published: April 2007

Burroughs, William James. 2005. Climate Change in Prehistory: The End of the Reign of Chaos. Cambridge: Cambridge University Press, 336 pp., $30.00 (UK£19.99). ISBN 0-521-82409-5 (Hardback).

Ruddiman, W. F. 2005. Plows, Plagues, and Petroleum: How Humans Took Control of Climate. Princeton: Princeton University Press, 272 pp., $24.95 (UK£15.95). ISBN: 0-691-12164-8.
Barriers to documenting occupational injuries among personal assistance services workers
Authors: Scherzer Teresa , Newcomer Robert
Published: May 2007

Background

Personal Assistance Services (PAS) workers provide essential support to disabled and elderly individuals living at home rather than institutions. Occupational injury risks are known, but limitations in occupational injury surveillance prevent assessing injury prevalence. Changing employment arrangements adopted by publicly funded programs may complicate the classification of PAS workers.

Methods

We surveyed state workers' compensation agencies and Financial Management Services organizations used by state Medicaid programs.

Results

Changing employment arrangements pose further barriers to classifying and documenting injury, and accessing workers' compensation coverage. Workers' Compensation coverage varies according to employment arrangements of the PAS workers. Financial Management Services organizations vary in their roles for reporting injury. Most frequent activities were providing written information about injury reporting, and reporting injuries to appropriate agencies or insurance companies.

Conclusions

Current limitations undercount the prevalence and consequences of PAS‐related occupational injuries among agency workers and largely ignore independent providers. Policy and research recommendations are presented. Am. J. Ind. Med. 50:536–544, 2007. © 2007 Wiley‐Liss, Inc.
Effect of TRITON™ X‐based dispersants bearing a carboxylic terminal group on rheological properties of BAM/ethyl cellulose/terpineol paste
Authors: Lee Don‐Ik , Lee Sang M. , S. Lee Eun , Choi Jae‐Young , Bae Jin‐Young
Published: May 2007

In this study, we attempted to use TRITON™ X (or octyl phenol ethoxylate (OPE) of different oxyethylene units (i.e., n = 2, 5, and 10))‐based dispersants containing a carboxylic group in the oxyethylene chain end for the formulation of BAM phosphor paste. Thus, a three‐component system employing OPE‐COOH as a dispersant, terpineol as a solvent, and ethyl cellulose as a binder was compounded with BAM particles, and the rheological properties of the paste were investigated in detail. Among three acidic TRITON X‐based compounds we tested (i.e., [OPE2‐COOH], [OPE5‐COOH], and [OPE10‐COOH]), OPE10‐COOH containing the highest number of oxyethylene units in the backbone was found to be the dispersant showing the lowest viscosity of BAM paste under identical conditions. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Small Sample Properties of Asymptotic Tests for Two Binomial Proportions
Authors: Dozzi M. , Riedwyl H.
Published: May 2007

We compare for n1, n2 = 10(10)50 and α = .01,.05 the following tests for two binomial proportions: chisquare, chisquare with YATES correction, chisquare with BERCHTOLD correction, chisquare with SCHOUTEN et al. correction, log likelihood ratio and t‐test. The chisquare test with BERCHTOLD correction has error probabilities that in the mean are closest to the significance level. Especially for α = .01 the difference between the power of the chisquare and t‐test is in many cases surprisingly small.
Comparing Stochastically Restricted Estimators in a Linear Regression Model
Authors: Baksalary J. K.
Published: May 2007

The minimum dispersion linear unbiased estimators of the vector of parameters in a linear regression model are compared when the parameters of the model are subject to stochastic linear restrictions with different dispersion matrices of the disturbances involved in them.
A New Test for Cross‐Over Clinical Trials with Order Effects
Authors: Le Chap T.
Published: May 2007

In cross‐over designs for the comparison of two treatments, A and B, each patient receives both treatments in a randomized order. We will consider such design when the response of each patient is binary and propose a new test for treatment effect incorporating the information available from like pairs of response.
Exact Simultaneous Comparisons with Control in an r × c Contingency Table
Authors: Passing H.
Published: May 2007

Let categorical data coming from a control group and (r ‐ 1) treated groups be given in an r × c contingency table. A simultaneous test procedure of the (r ‐ 1) hypotheses that the probabilities of all c categories do not differ between the i‐th treated group and the control is derived. For small tables and small cell frequencies it is exactly performed by generation of all tables having the given marginal sums. If 2 categories or 2 groups only are given the asymptotic distribution of the test statistic is known; otherwise its distribution may be simulated if the computational expenditure of performing an exact test is too large. By means of a Monte Carlo study it is shown that this method meets its level more reliably and that it has a better power than others.
A Simple Numerical Procedure for Estimating the Prior Probability in the Biomathematical Proof of Paternity
Authors: Böhning D.
Published: May 2007

This note gives a simple procedure for finding the maximum likelihood estimate of the prior probabilities in paternity cases. The procedure is based on a fixed point principle.
Maximum Likelihood Estimation of the Mortality Rate Function
Authors: Dimitrov B. N. , Rachev S. T. , Yakovlev A. Yu.
Published: May 2007

Maximum likelihood estimator is obtained for the mortality rate function of a specific type appearing in survival data analysis. Strict consistency of this estimator is proved.
The Statistical Analysis for Incomplete Diallel Cross Series. Fixed Model Analysis of Variance
Authors: Mǎdry W. , Ubysz‐Borucka L. , Piotrowski W.
Published: May 2007

This paper presents modern statistical methods used for quantitative genetics and plant breeding. It contains biometrioal analysis principles of fixed model for an identical, incomplete diallel cross series. The theory of vector space is used for estimation of parameters assumed in the model and for performance of the analysis of variance. As a result, the estimation of all groups of parameters treated in the model, is independent. Theoretical results are illustrated by numerical examples from winter wheat breeding.
Missing Plot Technique in Diallel Crosses for Griffing Method‐III
Authors: Kaushik L. S. , Puri P. D.
Published: May 2007

The method of combining ability analysis of diallel crosses for Griffing method‐3 for one and two missing observations has been presented. The formulae for estimating the parameters, the variances of different estimates and the sum of squares for various effects have been presented. The given analysis can easily be extended for the case of missing of more than two observations. The procedure of analysis has been illustrated through an example.
Exact Calculation of Permutational Distributions for Two Independent Samples
Authors: Zimmmermann H.
Published: May 2007

A simple Fortran Subroutine is given for the exact calculation of permutational distributions for two independent samples. Important special cases are the Fisher‐Pitman randomization test, the Mann‐Whitney U‐test, the Mantel‐Haenszel‐test and the exact test for 2×k contingency tables. The algorithm needs polynomial time and is of use even for personal‐ or microcomputers.
The Concept of Additivity of Drug Combinations in the Case of Quantal Response
Authors: Wolf Th. , Unkelbach H.‐D.
Published: May 2007

The concept of additivity of drug combinations is widely accepted in pharmacology and toxicology. Up to now, no general statistical methods to test that property are available. The present paper gives a mathematical formulation of additivity, a method to fit dose response surfaces under additivity assumption and a statistical test.
Equivalence or Selection: A Distribution‐Free Approach
Authors: Desu M. M. , Bristol David R.
Published: May 2007

Using a distribution‐free approach, a modification of the usual procedure for selecting the better of two treatments is presented. Here the possibility of no selection when the treatments appear to be ‘equivalent’ is allowed. The sample size and the constant needed to implement the proposed procedure are determined by controlling the probabilities of a correct selection and a wrong selection when the two treatments are not equivalent.
A Finite Stage Decision Procedure in the Analysis of Variance
Authors: Pfuff F.
Published: May 2007

In this paper we have developed a finite stage Bayes test in the analysis of variance. Determining such a decision rule the losses of erroneously accepting the hypotheses as well as the observation costs and the a priori probabilities were considered. We have given a method of constructing the continuation intervals (at, bt) (t = 1, …, r) of a r‐stage test and have demonstrated how the decision process operates. Furthermore it has been investigated in which way the Bayes risk depends on the several parameters. Especially we have shown that the Bayes risk of an r‐stage test is much smaller than the Bayes risk of a corresponding test with fixed sample size as a rule.
Goodness‐of‐Fit Tests for the Logistic Regression Model for Matched Case‐Control Studies
Authors: Hosmer David W. , Lemeshow Stanley
Published: May 2007

A number of statistics have recently been proposed to asssess the fit of the multiple logistic regression model in both prospective and retrospective studies involving two independent samples as well as in cross sectional studies. These statistics are not appropriate for assessing fit with matched case‐control studies.

This paper presents methods for assessing fit for matched case‐control studies. Both parametric and nonparametric approaches are suggested even though none are directly analogous to the statistics proposed in the unmatched situation. Several examples are included to illustrate the methods.
Testing for the Equality of the Variance‐Covariance Matrices of Two Jointly Normal Vector Variables
Authors: Smith Patricia L. , Kshiesagar Anant M.
Published: May 2007

Assume a joint 2P‐variate normal distribution for the p‐component vectors x and y with unknown mean and unknown variance‐covariance matrices Σxx and Σyy respectively, with Cov (x, y)=Σxy. No assumptions are made about the nature of Σxy. The likelihood ratio method is investigated to test the hypothesis that Σxx = Σyy. A method of numerical solution to the likelihood equations in the restricted parameter case is given when p=2, and approximate solutions are suggested for p>2.
Statistical Analysis of Data from Gene Frequency Perturbation Experiments
Authors: Wilson S. R. , Oakeshott J. G.
Published: May 2007

Data from gene frequency perturbation experiments are being used to resolve the selectionistneutralist debate over the evolutionary significance of electrophoretic enzyme variation. Previous statistical analyses of such data have encountered the major difficulty that the effective population size is not known. In this article, we give the statistical theory for fitting various selection models, and we evaluate the known asymptotic results by simulation. We also show that there is further information in data from these experiments besides the estimates of the selection parameters, namely estimates of the bounds for the effective population sizes.
Variance Component Estimation for Dichotomous Characters and Its Use for Estimating Heritability
Authors: Guiard V. , Örfer G. Herrend , Tuchscherer A.
Published: May 2007

By transforming dichotomous characters (for instance the presence or absence of a certain disease) to zero‐one characters it is possible to estimate the variance and variance components. This paper explains the peculiarities occurring in the linear model and estimation functions and the application of the method for heritability estimation.
Multinomial Distribution and Ascertainment Models
Authors: Gupta A. K. , Lindle S. G.
Published: May 2007

In this paper general ascertainment models are studied relaxing the strong assumption of complete dominance. Probabilitis of ascertaiment for both the complete and incomplete models depending on family size and register size for two types of affected individuals are derived.
Comment on Kannemann's “The Exact Evaluation of 2‐way Cross‐classifications”
Authors: Kroonenberg Pieter M. , Verbeek Albert
Published: May 2007

KANNEMANN (1982 a, b) is critisized on several points, primarily using results available in the literature prior to his papers.
Estimating Population Size and Density Using Line Transect Sampling
Authors: Anderson D. R. , Burnham K. P. , Crain B. R.
Published: May 2007

ANDERSON and POSPAHALA (1970) investigated the estimation of wildlife population size using the belt or line transect sampling method and devised a correction for bias, thus leading to a class of estimators with desirable characteristics. This work was given a basic and rigorous mathematica framework by BURNHAM and ANDERSON (1976). In the present article we use this mathematical framework to develop an estimator of population size and density using weighted least squares. The approach is a two‐stage Method.
Some Mathematical Models for Line Transect Sampling
Authors: Anderson D. R. , Burnham K. P. , Crain B. R.
Published: May 2007

ANDERSON and POSPAHALA (1970) investigated the estimation of wildlife population size using the belt or line transect sampling method and devised a correction for bias, thus leading to an estimator with interesting characteristics. This work was given a uniform mathematical framework in BURNHAM and ANDERSON (1976). In this paper we extend that mathematical framework to several different sampling models, and a number of interesting discrete probability distributions emerge.