bluuebunny/crossref_metadata_2025 huggingface dataset:
Chiton myogenesis: Perspectives for the development and evolution of larval and adult muscle systems in molluscs
Authors: Wanninger Andreas , Haszprunar Gerhard
Published: September 2002

We investigated muscle development in two chiton species, Mopalia muscosa and Chiton olivaceus, from embryo hatching until 10 days after metamorphosis. The anlagen of the dorsal longitudinal rectus muscle and a larval prototroch muscle ring are the first detectable muscle structures in the early trochophore‐like larva. Slightly later, a ventrolaterally situated pair of longitudinal muscles appears, which persists through metamorphosis. In addition, the anlagen of the putative dorsoventral shell musculature and the first fibers of a muscular grid, which is restricted to the pretrochal region and consists of outer ring and inner diagonal muscle fibers, are generated. Subsequently, transversal muscle fibers form underneath each future shell plate and the ventrolateral enrolling muscle is established. At metamorphic competence, the dorsoventral shell musculature consists of numerous serially repeated, intercrossing muscle fibers. Their concentration into seven (and later eight) functional shell plate muscle bundles starts after the completion of metamorphosis. The larval prototroch ring and the pretrochal muscle grid are lost at metamorphosis. The structure of the apical grid and its atrophy during metamorphosis suggests ontogenetic repetition of (parts of) the original body‐wall musculature of a proposed worm‐shaped molluscan ancestor. Moreover, our data show that the “segmented” character of the polyplacophoran shell musculature is a secondary condition, thus contradicting earlier theories that regarded the Polyplacophora (and thus the entire phylum Mollusca) as primarily eumetameric (annelid‐like). Instead, we propose an unsegmented trochozoan ancestor at the base of molluscan evolution. J. Morphol. 251:103–113, 2002. © 2002 Wiley‐Liss, Inc.
Quantification of grafted poly(ethylene glycol)‐silanes on silicon by time‐of‐flight secondary ion mass spectrometry
Authors: Norrman K. , Papra A. , Kamounah F. S. , Gadegaard N. , Larsen N. B.
Published: September 2002

Silicon grafted monodisperse poly(ethylene glycol) (PEG) silanes with various PEG chain lengths and mixtures of these were systematically analyzed with static time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS). The mass spectra show differences in the various relative signal intensities, an observation that was used to elucidate important aspects of the grafting process. The relationship between PEG‐silane fragment ion abundances and Si+ ion abundances were used to (i) qualitatively describe layer thicknesses of grafted mixtures of PEG‐silanes on silicon, (ii) construct a calibration curve from which PEG chain length (or molecular mass) can be determined and (iii) quantitatively determine surface mixture compositions of grafted monodisperse PEG‐silanes of different chain lengths (3, 7 and 11 PEG units). The results suggest that discrimination does take place in the adsorption process. The PEG‐silane with the shorter PEG chain is discriminated for mixtures containing PEG3‐silane, whereas the PEG‐silane with the longer PEG chain is discriminated in PEG7/PEG11‐silane mixtures. The origin of this difference in adsorption behavior is not well understood. Aspects of the grafting process and the TOF‐SIMS analyses are discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Molecular changes associated with the transmission of avian influenza a H5N1 and H9N2 viruses to humans*
Authors: Shaw M. , Cooper L. , Xu X. , Thompson W. , Krauss S. , Guan Y. , Zhou N. , Klimov A. , Cox N. , Webster R. , Lim W. , Shortridge K. , Subbarao K.
Published: September 2002

In order to identify molecular changes associated with the transmission of avian influenza A H5N1 and H9N2 viruses to humans, the internal genes from these viruses were compared to sequences from other avian and human influenza A isolates. Phylogenetically, each of the internal genes of all sixteen of the human H5N1 and both of the H9N2 isolates were closely related to one another and fell into a distinct clade separate from clades formed by the same genes of other avian and human viruses. All six internal genes were most closely related to those of avian isolates circulating in Asia, indicating that reassortment with human strains had not occurred for any of these 18 isolates. Amino acids previously identified as host‐specific residues were predominantly avian in the human isolates although most of the proteins also contained residues observed previously only in sequences of human influenza viruses. For the majority of the nonglycoprotein genes, three distinct subgroups could be distinguished on bootstrap analyses of the nucleotide sequences, suggesting multiple introductions of avian virus strains capable of infecting humans. The shared nonglycoprotein gene constellations of the human H5N1 and H9N2 isolates and their detection in avian isolates only since 1997 when the first human infections were detected suggest that this particular gene combination may confer the ability to infect humans and cause disease. J. Med. Virol. 66:107–114, 2002. Published 2002 Wiley‐Liss, Inc.
Constellations and careers: toward understanding the effects of multiple developmental relationships
Authors: Higgins Monica C. , Thomas David A.
Published: September 2002

This paper examines the effects of individuals' primary and multiple developmental relationships in a longitudinal study of the careers of lawyers. By juxtaposing the effects of the primary developmental relationship with those of individuals' sets or ‘constellations’ of developmental relationships, the present study lends insight into if and when these two perspectives on mentoring yield different results regarding the effects of mentoring on protégé career outcomes. The findings from the present study show that while the quality of one's primary developer affects short‐term career outcomes such as work satisfaction and intentions to remain with one's firm, it is the composition and quality of an individual's entire constellation of developmental relationships that account for long‐run protégé career outcomes such as organizational retention and promotion. Further, results from the present study provide evidence that the constellation perspective explains greater variance with respect to protégé career outcomes than does the primary or more traditional perspective on mentoring. Implications for research on mentoring, developmental relationships, and careers are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
The effect of distal learning, outcome, and proximal goals on a moderately complex task
Authors: Seijts Gerard H. , Latham Gary P.
Published: September 2002

The effects of learning versus outcome distal goals in conjunction with proximal goals were investigated in a laboratory setting using a class‐scheduling task. The participants (n = 96) needed to acquire knowledge in order to perform the task correctly. A ‘do your best’ outcome goal led to higher performance than the assignment of a specific, difficult outcome goal. However, the assignment of a specific, difficult learning goal led to higher performance than urging people to ‘do their best.’ Goal commitment was higher in the learning goal than in the outcome goal condition. The correlation between task‐relevant strategies discovered and performance was positive and significant. The number of task‐relevant strategies implemented by participants assigned a distal learning goal in conjunction with proximal goals was higher than in any other goal condition. Setting a distal outcome or learning goal that included proximal outcome goals, however, did not lead to higher performance than the setting of a distal outcome or learning goal alone. Self‐efficacy correlated significantly with performance, and this effect was mediated through strategy development. Furthermore, the discovery of task‐relevant strategies affected self‐efficacy through an increase in performance. Copyright © 2001 John Wiley & Sons, Ltd.
Spatial variations in the average rainfall–altitude relationship in Great Britain: an approach using geographically weighted regression
Authors: Brunsdon C. , McClatchey J. , Unwin D.J.
Published: September 2002

The relationship between annual rainfall totals and gauge elevation over Great Britain is re‐examined using the recently developed technique of geographically weighted regression (GWR). This enables the spatial drift of regression parameters to be identified, estimated and mapped. It is shown that the rate of increase of precipitation with height, or height coefficient, varies from around 4.5 mm/m in the northwest to almost zero in the southeast. There is a particularly rapid change in this value across the English Midlands. The predicted sea level precipitation varies from 1250 mm to less than 600 mm in much the same way. Copyright © 2001 Royal Meteorological Society
Monsoon rainfall variations and teleconnections over South and East Asia
Authors: Kripalani R.H. , Kulkarni Ashwini
Published: September 2002

Seasonal summer monsoon (June–September) data for 120 stations over East Asia (China, Japan, Mongolia, Korea) varying from 1881 to 1998 are utilized to understand their interannual and climate characteristics, and to investigate their teleconnections with South Asian (in particular India's) monsoon rainfall. Contemporaneous relations on an interannual time‐scale reveal that the rainfall variations over north China (southern Japan) are in‐phase (out‐of‐phase) with South Asian rainfall.

Based on the instrumental data available, regional rainfall anomaly time series for the 118‐year period for the two coherent regions, over north China and southern Japan are prepared. All the three series (India, China, Japan) have been subjected to statistical tests. Results reveal that while there are year‐to‐year fluctuations, the Mann–Kendall rank statistic suggests no significant long‐term trends. However, the application of Cramer's statistic to study the short‐term climate variability depicts decadal variability with certain epochs of above and below normal rainfall over each region. The epochs tend to last for about three decades over India and China, and about five decades over Japan. The turning points for China follow those of India about a decade later.

The relationships of South and East Asian monsoon rainfall exhibit secular variations. The inter‐connections between the monsoon‐related events (rainfall over South Asia, rainfall over East Asia, Northern Hemisphere circulation, tropical Pacific circulation) appear to strengthen (or weaken) around the same time, implying that the monsoon related events over geographically separated regions seem to get linked (or delinked) around the same time. Copyright © 2001 Royal Meteorological Society
Spatial grouping of United States climate stations using a hybrid clustering approach
Authors: DeGaetano Arthur T.
Published: September 2002

The development of a hybrid clustering technique based on the geographic proximity of observing stations and some application‐driven measure of statistical similarity (in this case rank correlation) is described. The procedure is then applied to temperature and precipitation data from the United States (US) Historical Climatology Network. The resulting station groups provide some insight into the number of observation stations that are necessary to monitor adequately the climate of the US.

Based on temperature data alone, a 287‐station subset of the original 1145 sites would be adequate to account for 80% of the spatial variability in seasonal temperature across the US. Geographically the distribution of these stations would be relatively sparse in the centre of the country with higher station density along the East Coast and from the Rocky Mountains to the West Coast. Generally, the temperature clusters match the existing US climate divisions to some extent. To monitor adequately the spatial variability of precipitation, a network of similar size could be used. However, such a network would only account for 65% of the spatial variability in precipitation. In this case, fairly uniform station density is indicated across the country with the highest station density in Florida and the Dakotas. A similar number of stations, but with slightly different geographic groupings would be adequate to monitor precipitation and temperature simultaneously. Copyright © 2001 Royal Meteorological Society
Climate variability in Malawi, part 2: sensitivity and prediction of lake levels
Authors: Jury M. R. , Gwazantini M. E.
Published: September 2002

Southern Africa has only a few large lakes, one of which is Lake Malawi. It forms part of the lower Zambezi catchment and the Great Rift Valley. The lake provides food, energy, transport and recreation to the local people. Inflow to the lake increases through summer (December to April) when the equatorial convection zone lies overhead. An analysis of lake levels in the period 1937–95 has been conducted and changes are related to variations in rainfall and atmospheric conditions. Interannual cycles in the time series are consistent with those found for Zambezi River streamflows, suggesting a degree of regional coherence. Years with high inflow are contrasted with mean conditions using the National Centres for Environmental Prediction reanalysis data for the period since 1958. Composite anomalies of wind fields for wet years reveal a zonal overturning circulation. Low (upper) level westerlies (easterlies) link with a sub‐tropical trough in the Mozambique Channel to enhance regional convection and lake inflows. The results provide input to predictive models for Lake Malawi to plan better the management of water resources in this part of Africa. Copyright © 2002 Royal Meteorological Society.
Stalagmite lamina doublets: a 1000 year proxy record of severe winters in northwest Scotland?
Authors: Baker Andy , Proctor Christopher J. , Barnes William L.
Published: September 2002

Stalagmites can contain annual luminescence laminae, and some samples provide long continuous chronologies from which climatic information can be extracted. One such site is Uamh an Tartair in Assynt, northwest Scotland, where most stalagmites contain continuous laminae sets for the last two to three millennia. At this site, the normal mode of deposition is for one luminescent lamina to be deposited in autumn, derived from luminescent organic matter that is flushed onto the sample from the overlying peat. However, in the stalagmite investigated here, 43 lamina doublets occur, where two laminae appear to be preserved in a winter. We argue, both from the timing of these events within the ‘Little Ice Age’, as well as from analogous situations in alpine streams, that the doublets occur due to the presence of a second, spring melt flush of organic matter. The interpretation of stalagmite double laminae, therefore, has considerable potential as a palaeoclimate proxy, and at our study site, we suggest one of severe winters over the last millennium. Copyright © 2002 Royal Meteorological Society.
The lake breeze–ground‐level ozone connection in eastern Wisconsin: a climatological perspective
Authors: Lennartson G. Jay , Schwartz Mark D.
Published: September 2002

The Lake Michigan Air Quality Region (LMAQR) experiences exceedances of the 1 h health standard for ozone numerous times each summer. Previous short‐term investigations have revealed that the lake breeze circulation is connected with very high levels of ozone in eastern Wisconsin (EWI). Findings from one of the more recent short‐term research efforts have led to the development of a generalized conceptual model that details the role that the lake breeze circulation plays in transporting ozone‐rich air of the Lake Michigan conduction layer onshore to EWI. Short‐term studies, however, are limited by the small number of cases examined. To understand the ozone–lake breeze relationship from a climatological perspective, we analysed the spatial and temporal pattern of 1 h ozone exceedances in EWI during the months of May through to September, over the period 1985–99. Further, we used Laird et al.'s recently developed technique for discriminating lake breeze days to determine which exceedance‐days over the period of our climatology occurred in association with lake breezes.

Our results show: (1) a decrease in both magnitude and frequency of exceedances of the 1 h ozone standard in EWI with increasing distance from the lakeshore; (2) a positive correlation between average onset time of the initial exceedance‐hour and a site's distance from Lake Michigan; (3) a very high percentage of initial exceedance‐hours occurring in association with southeasterly surface air flow; and (4) exceedances occurring in association with lake breezes 82.1% of the time at near‐shore sites.

Collectively, our findings provide strong evidence that the lake breeze circulation is closely associated with the distribution of ozone in EWI in both space and time. Moreover, our results show that the lake breeze circulation is directly associated with a significant proportion of the exceedances of the 1 h ozone standard in EWI–particularly at near‐shore sites. Thus, mandated reductions in regional‐scale NOx may be sufficient to allow ‘inland’ locations in EWI to meet the new 8 h, 80 ppb Environmental Protection Agency health standard. However, further reductions in volatile organic compounds and NOx within the major metropolitan centres of the LMAQR will likely be necessary if ‘shoreline’ locations in EWI are to meet the 1 h standard, and the stricter 8 h standard in the future. Copyright © 2002 Royal Meteorological Society.
Redating the onset of burning at Lynch's Crater (North Queensland): implications for human settlement in Australia
Authors: Turney C. S. M. , Kershaw A. P. , Moss P. , Bird M. I. , Fifield L. K. , Cresswell R. G. , Santos G. M. , Di Tada M. L. , Hausladen P. A. , Zhou Y.
Published: September 2002

Lynch's Crater preserves a continuous, high‐resolution record of environmental changes in north Queensland. This record suggests a marked increase in burning that appears to be independent of any known major climatic boundaries. This increase is accompanied, or closely followed, by the virtually complete replacement of rainforest by sclerophyll vegetation. The absence of any major climatic shift associated with this increase in fire frequency therefore has been interpreted as a result of early human impact in the area. The age for this increase in burning, on the basis of conventional radiocarbon dating, was previously thought to be approximately 38 000 14C yr BP, supporting the traditional model for human arrival in Australia at 40 000 14C yr BP Here we have applied a more rigorous pre‐treatment and graphitisation procedure for radiocarbon dating samples from the Lynch's Crater sequence. These new dates suggest that the increase in fire frequency occurred at 45 000 14C yr BP, supporting the alternative view that human occupation of Australia occurred by at least 45 000–55 000 cal. yr BP. Copyright © 2001 John Wiley & Sons, Ltd.
Raman microprobe spectroscopy and transmission electron microscopy of thermal sprayed ZrO2 coatings before and after rub testing of outer air seals
Authors: Witke K. , Österle W. , Skopp A. , Woydt M.
Published: September 2002

8 wt% Y2O3–ZrO2 spray powder and thermally sprayed as thermal barrier coatings on outer air seals were characterized by Raman microprobe spectroscopy (RMS) and transmission electron microscopy to investigate the lateral distribution, composition, structure and grain size of ZrO2 phases and to separate ZrO2 and Y2O3. RMS of transfer layers on ZrO2‐coated shrouds after rub tests against SiC laser‐tipped metallic blades showed the formation of metallic oxides MeIMeII2O4 of spinel type. Wear tracks were partly covered by graphite and spinel‐type oxides. In some cases, the latter were better detectable after laser enhanced cleaning by burning off the covering carbon layer. Copyright © 2001 John Wiley & Sons, Ltd.
Intestinal structure and function of broiler chickens on diets supplemented with a mannan oligosaccharide
Authors: Iji Paul A , Saki Ali A , Tivey David R
Published: September 2002

A study was conducted to evaluate the response of broiler chickens to a commercial synthetic mannan oligosaccharide, Bio‐Mos™ (BM), included in sorghum/lupin‐based diets at 0.0, 1.0, 3.0 or 5.0 g kg−1 diet. The diets were fed between 7 and 28 days of age, and both the gross response and mechanisms involved were evaluated. The highest level of BM in the diet resulted in longer (P < 0.01) jejunal villi than those observed at other levels of supplementation. The RNA content of the ileal mucosal homogenate was significantly greater (P < 0.05) in chicks raised on diets supplemented with 3.0 and 5.0 g BM kg−1 diet than in other groups. The protein/DNA ratio of the jejunal mucosal homogenate was also higher (P < 0.05) in chicks fed the 1.0 g BM kg−1 diet than in chicks fed the other diets. The protein/RNA and RNA/DNA ratios in ileal homogenates were significantly (P < 0.01) influenced by the presence of BM in the diet. There were significantly greater specific activities of maltase (P < 0.01), leucine aminopeptidase (P < 0.05) and alkaline phosphatase (P < 0.001) in the jejunum as a result of supplementation with BM. Digestive enzyme activities in the ileum were unaffected. L‐Tryptophan uptake by jejunal brush‐border membrane vesicles was significantly higher (P < 0.01) in chicks raised on the 5.0 g BM kg−1 diet than in the other chicks. The supplement led to minor improvement in body weight but no improvement in feed conversion ratio. These effects were related to changes in digestive enzyme activities and, perhaps, amino acid transport.

© 2001 Society of Chemical Industry
Study and quantification of monomeric flavan‐3‐ol and dimeric procyanidin quinonic forms by HPLC/ESI‐MS. Application to red wine oxidation
Authors: de Gaulejac Nathalie Vivas , Vivas Nicolas , Nonier Marie‐Françoise , Absalon Christelle , Bourgeois Guy
Published: September 2002

Monomeric flavan‐3‐ols and dimeric procyanidins of red wine were oxidised by two processes, chemical and enzymatic. Unstable quinonic forms were stabilised by sulphonation, and the resulting sulphones were quantified by coupled HPLC/ESI‐MS. The effects of temperature and UV light on the oxidation of phenolic compounds were also investigated. The concentration of quinones increased with increasing temperature, but the kinetics of the reaction was independent of temperature. Likewise, more quinones were formed in the presence of UV light than in its absence, but UV light also did not affect the kinetics of the reaction. Thus temperature and UV light affect the quantity of quinones formed but not the rate at which they appear.

© 2001 Society of Chemical Industry
Retinoic acid–induced expression of autotaxin in N‐myc–amplified neuroblastoma cells
Authors: Dufner‐Beattie J. , Lemons R. S. , Thorburn A.
Published: September 2002

Neuroblastoma, the most common extracranial solid tumor in children, arises from precursors of the sympathetic nervous system. Neuroblastoma cell lines are responsive to the differentiation agent retinoic acid, which induces its effects by altering transcription rates of specific target genes. We identified autotaxin (ATX), which encodes an autocrine tumor motility‐stimulating factor, as a gene whose expression is significantly induced by retinoic acid in neuroblastoma cells. ATX induction was specific for neuroblastoma cell lines that contain N‐myc amplification, a cytogenetic feature commonly associated with aggressive neuroblastomas. Although ATX expression was associated with amplification of the N‐myc locus, N‐myc itself was neither sufficient nor required for ATX expression, suggesting that a coamplified gene is responsible. ATX induction by retinoic acid was due to increased transcription and required new protein synthesis. © 2001 Wiley‐Liss, Inc.
Role of intracellular interleukin‐1 receptor antagonist in skin carcinogenesis
Authors: La Eunhye , Rundhaug Joyce E. , Fischer Susan M.
Published: September 2002

Interleukin 1 (IL‐1) is a major mediator of inflammation and exerts pleiotropic effects on many systems. To elucidate the role of its endogenous inhibitor, intracellular IL‐1 receptor antagonist (icIL‐1Ra), in mouse skin, we produced an icIL‐1Ra–overexpressing skin carcinoma cell line (icIL‐1Ra‐JWF2). Altered expression of icIL‐1Ra did not change IL‐1α mRNA levels in these transfected cells. In icIL‐1Ra‐JWF2 cells, however, cyclooxygenase‐2 mRNA levels were dramatically reduced and shown to be transcriptionally regulated by icIL‐1Ra. To determine the effect of icIL‐1Ra on cell proliferation, cell counts were done 24 h after plating equal numbers of cells. Cells from three icIL‐1Ra‐JWF2 clones showed significantly reduced growth rates compared with parental JWF2 cells. We subcutaneously injected five independent clones of icIL‐1Ra‐JWF2 cells into nude mice and measured the tumor doubling time by weekly measurements of tumor volume. IcIL‐1Ra appeared to significantly slow the growth of tumors in vivo. Collectively these observations suggest that IL‐1Ra has antiproliferative effects in murine skin carcinoma cells. © 2001 Wiley‐Liss, Inc.
Effects of some pharmacological agents on the survival of unipedicled venous flaps: an experimental study
Authors: Askar Ibrahim , Saray Aydin , Gurlek Ali , Sevin Kutlu , Sabuncuoglu Bizden Tavil
Published: September 2002

Clinical and experimental studies have been conducted to improve the survival of venous flaps. As a result of these studies, although various survival mechanisms were raised, none obtained satisfactory information. Venous stasis, and the resultant venous thrombosis, is a factor that decreases the survival of venous flaps. In this study, we evaluated the effects of two antiinflammatory agents, etodolac and etofenamate, on the survival of unipedicled venous flaps. In this study, 35 male New Zealand white rabbits (3,500–4,000 g) (70 ears) were used. Perichondrocutaneous flaps, 3 × 4.5 cm in size, were designed and raised, keeping the central veins intact in the middle of venous flap. Central arteries and nerves were ligated and transected both proximally and distally, to prepare unipedicled venous flaps. A silicone sheet was placed between the cartilage tissue and flap, to prevent blood flow and revascularization beneath. The subjects were divided into seven groups, consisting of five rabbits (10 ears). In the negative control group (group I), the single vascular pedicle of venous flaps, central veins were ligated and flaps sutured into their own place as the composite graft. In the positive control group (group II), after venous flaps were prepared, normal saline, 0.2 mL, was given subcutaneously. In the first of five experimental groups (group III), unfractionated heparin (100 U/day) was given subcutaneously. In the second experimental group (group IV), etodolac (5 mg/kg/day) was given subcutaneously. In the third experimental group (group V), etophenamate (5 mg/kg/day) was given orally through a feeding tube. In the fourth experimental group (group VI), parnaparin (5 anti‐Xa U/kg/day) was given subcutaneously. In the fifth experimental group (group VII), nadroparin (5 anti‐Xa U/kg/day) was given subcutaneously, about 7 days postoperatively. At the eighth postoperative day, surviving areas of venous flaps were measured, and the results were evaluated by Kruskal‐Wallis ANOVA and Mann‐Whitney U‐test (P < 0.05). Biopsies were also taken from the flaps for histological evaluation of border of necrotic tissue. Surviving areas of unipedicled venous flaps were larger in experimental groups than those in negative and positive control group (P < 0.05). However, comparison of the experimental groups demonstrated no statistically significant difference (P > 0.05). We concluded that all pharmacological agents used in the experimental groups succeeded in increasing the survival of unipedicled venous flaps. Survival of the unipedicled venous flap was higher in venous flaps than that of composite graft, clearly showing the importance of the venous pedicle. © 2001 Wiley‐Liss Inc. MICROSURGERY 21:350‐‐356, 2001
Vascular fluid dynamics and vascular biology and disease
Authors: Caro C. G.
Published: September 2002

My tribute to James Lighthill, one of the world's great mathematical scientists, is offered with admiration and sadness—he was both colleague and friend. I met James in 1964, through an introduction by Sir Geoffrey (G.I.) Taylor. He was then Royal Society Research Professor at Imperial College and I was a lecturer in medicine at St. Thomas's Hospital, with a particular interest in cardiovascular and respiratory mechanics. Within a short while we began to collaborate and about a year later James proposed to Imperial College that it should take the then almost unique step of setting up an activity in physiological flow. The Physiological Flow Studies Unit was started at the College in 1966—on an experimental basis with a staff of one (the writer). Looking back over a period of more than 30 years, I have three outstanding, interrelated impressions. First, that the field of physiological fluid dynamics has grown hugely worldwide, attesting in no small measure to James Lighthill's prescience and contributions. Second, that close collaboration between life scientists and doctors and engineers and physical scientists, has led to great advances in the understanding of normal and disturbed biology and of the relevant fluid dynamics. Third, that recognition that mechanical stresses play a key role in cellular and molecular biology, has given a tremendous boost to physiological mechanics. My aim in this note is to describe some earlier and current work on vascular fluid dynamics and vascular biology and disease and, where appropriate, to trace its descent from early studies undertaken with James. Copyright © 2001 John Wiley & Sons, Ltd.
Transitions in function at low Reynolds number: hair‐bearing animal appendages
Authors: Koehl M. A. R.
Published: September 2002

Many types of animals use appendages bearing arrays of hair‐like structures to capture molecules (e.g. olfactory antennae, gills) or particles (e.g. suspension‐feeding appendages) from the surrounding water or air, and to locomote or move fluid past themselves. The performance of these functions depends on how much of the fluid encountered by the array of hairs flows through the gaps between the hairs rather than around the perimeter of the whole array. By modelling such arrays of hairs as rows of finite width of cylinders operating at low Reynolds numbers, the fluid velocity fields with respect to the hairs were calculated. Such models revealed a transition from non‐leaky to leaky behaviour as Re was increased. The purpose of this paper is to provide a brief review of the features of this transition as revealed by models, and then to describe examples of how animals use the transition in fluid flow to perform particular functions: rejection of captured material by copepods, and sniffing by lobsters. Copyright © 2001 John Wiley & Sons, Ltd.
On the potential of graded‐chiral Dallenbach absorbers
Authors: Reinert Jens , Psilopoulos Jannis , Grubert Jens , Jacob Arne F.
Published: September 2002

In this contribution, the potential of graded‐chiral/dielectric absorbers is explored theoretically. To this end, two different design procedures are introduced that allow us to improve single‐layer and graded‐dielectric Dallenbach absorbers. Both design concepts finally lead to graded‐chiral/dielectric Dallenbach absorbers. The first experiments prove the concept, and allow us to identify and discuss the effects and problems associated with the practical realization. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 254–257, 2001.
The role of hormones in breast carcinogenesis: Issues of relevance to female childhood cancer survivors*
Authors: Ganz Patricia A.
Published: September 2002

Breast cancer is the most common cancer among women in Western industrialized countries, and is an important potential second cancer to consider in young women who are survivors of childhood or adolescent cancers. This paper reviews the relationship between hormones and breast biology, cancer treatment factors that may increase or reduce the risk of breast cancer in female survivors of childhood cancer, the treatment of ovarian failure in these survivors, and the potential for preventive strategies in this population. The expanding numbers of female childhood cancer survivors increase the need for health care providers to understand the late health effects of treatments on reproductive health and breast cancer risk. Med. Pediatr. Oncol. 36:514–518, 2001. © 2001 Wiley‐Liss, Inc.
Psychological aspects of cancer screening in high‐risk populations*
Authors: Kash Kathryn M. , Dabney Mary Kay
Published: September 2002

Background

The focus of this paper is to define who is at high risk for breast cancer and the psychological issues in breast cancer screening. Within this context, the emphasis is on secondary malignancies after treatment for childhood cancers, including age appropriate guidelines for cancer screening. While there have been no studies of distress in women at high risk for breast cancer related to childhood cancer treatments, we can extrapolate from this study of women at high risk for breast cancer because of genetic susceptibility.

Methods

Three hundred and ninety one women at increased risk for developing breast cancer from rural and urban areas of the United States completed a questionnaire regarding genetic testing, psychological distress, and health beliefs. They were compared with 382 age‐matched controls, from the same geographical areas, with no family history of breast cancer in a first degree relative.

Results

A multiple regression analysis revealed that the best predictors of willingness to undergo genetic testing were: greater perception of being a gene mutation carrier, fewer negative and more positive aspects to testing, being at higher risk for breast cancer, and greater breast cancer anxiety (30% of variance).

Conclusions

Greater anxiety increased interest in testing but decreased adherence to screening behaviors. Women who have had childhood cancers with chest radiation treatment are at higher risk for breast cancer. The information gleaned from this study can be adapted to help them learn their real risk for developing breast cancer and to understand the importance of screening in the early detection of breast cancer. Med. Pediatr. Oncol. 36:519–524, 2001. © 2001 Wiley‐Liss, Inc.
Prediction of health behaviors in pediatric cancer survivors
Authors: Tyc Vida L. , Hadley Wendy , Crockett Genea
Published: September 2002

Background

It is important to understand the factors that motivate survivors of childhood cancer to engage in healthy behaviors. This is because of their susceptibility to adverse late effects from their malignancy and its treatment. We specifically examined sociodemographic and health perception variables as predictors of health‐protective behaviors in pediatric cancer survivors.

Procedure

Forty‐six patients, ages 10–18 years, who were previously treated for cancer and were 1–4 years off‐therapy, were assessed using a battery of testing instruments.

Results

Preadolescent and adolescent cancer survivors reported moderately frequent practice of a variety of health‐protective behaviors. The prevalence of risky health behaviors, as indicated by alcohol and tobacco use, was low. Regression analyses indicated that the practice of health‐protective behaviors was best predicted by patient's age and socioeconomic status (SES); younger adolescents and patients from higher SES more frequently engaged in healthy behaviors. Health perception variables were not significantly related to health‐protective behaviors. This was true despite findings that survivors perceived themselves to be vulnerable to health problems, identified a need to protect their health, and perceived their health outcomes to be largely determined by their own behaviors.

Conclusions

Sociodemographic factors should be kept in mind when designing interventions to promote continuing good health for young cancer survivors. Also to be included is the assessment of specific health risks secondary to the cancer therapies given. Risk counseling that recognizes and builds on these variables will be most effective in helping this patient population observe sound health habits. Med. Pediatr. Oncol. 37:42–46, 2001. © 2001 Wiley‐Liss, Inc.
Proliferative and apoptotic differences between alveolar rhabdomyosarcoma subtypes: A comparative study of tumors containing PAX3‐FKHR or PAX7‐FKHR gene fusions
Authors: Collins Margaret H. , Zhao Huaqing , Womer Richard B. , Barr Frederic G.
Published: September 2002

Background

Most alveolar rhabdomyosarcomas (ARMS) have chromosome translocations and resultant gene fusion products. The more common translocation fuses the PAX3 and FKHR genes; patients who have PAX3‐FKHR‐positive ARMS have reduced event‐free survival compared to patients with ARMS containing the less common translocation that fuses the PAX7 and FKHR genes.

Procedure

We examined histology, immunohistochemical markers of differentiation, and cell cycle characteristics of a panel of ARMS containing either PAX3‐FKHR or PAX7‐FKHR transcript to determine if these features differ between the ARMS subsets.

Results

Cell cycle parameters varied significantly: the number of nuclei that stained with either an immunohistochemical marker of proliferation (MIB1), or a TUNEL‐based assay for apoptosis was significantly greater in tumors that expressed PAX3‐FKHR compared to tumors that expressed PAX7‐FKHR transcript.

Conclusions

We conclude that compared to PAX7‐FKHR‐containing tumors, ARMS that contain PAX3‐FKHR transcript have (1) increased cell proliferation, consistent with greater loss of cell cycle regulation, and (2) apoptosis that is increased but insufficient to prevent tumor formation. More marked cell cycle dysregulation may contribute to poorer prognosis for patients with ARMS that have PAX3‐FKHR fusion. Med Pediatr Oncol 2001;37:83–89. © 2001 Wiley‐Liss, Inc.
NMR processing techniques based on multivariate data analysis and orthogonal signal correction. 13C CP/MAS NMR spectroscopic characterization of softwood kraft pulp
Authors: Hauksson Jón B. , Edlund Ulf , Trygg Johan
Published: September 2002

This paper presents a novel way of extracting information from a series of severely overlapped NMR spectra using multivariate data analysis techniques. A number of softwood pulps were prepared from wood chips that were subjected to kraft cooking conditions in laboratory digesters. In addition to measurements of traditional physical parameters, the pulps were characterized using standard 13C CP/MAS NMR spectroscopy. The relationship between the kappa number and both the NMR time domain and frequency domain data was modeled using multivariate data analysis techniques. The variation in the NMR spectra that was not correlated with the kappa number was removed using a new preprocessing tool, orthogonal signal correction (OSC). The resulting OSC‐treated NMR spectra were used as descriptors to generate partial least‐squares projections to latent structures (PLS) models for the variation of the kappa number. PLS weights were used to generate NMR ‘sub‐spectra’ which correspond to changes in the pulps that occur as the pulping process proceeds from high to low values of the kappa number. The sub‐spectra were used to gain insight into the changes in the pulps occurring at the molecular level. Concomitant changes in cellulose crystallinity and the amounts of hemicellulose and lignin were observed in these sub‐spectra. Copyright © 2001 John Wiley & Sons, Ltd.
1H NMR isotope shifts arising from the substitution of 12C by 13C: application to polycyclic aromatic hydrocarbon anions
Authors: Hoffman Roy E. , Treitel Noach , Rabinovitz Mordecai
Published: September 2002

Isotope shifts are a well‐established tool for structural analysis by NMR. The substitution of a protium with a deuterium is the most widely studied of these effects. However, such studies call for specific deuteration that requires complex synthetic techniques owing to the low natural abundance of deuterium. 13C occurs at a higher natural abundance and couples strongly with its attached proton. We have developed and refined a method to reliably observe these much smaller shifts without needing to resort to chemical synthesis. We show that carbon induced isotope shifts reflect structural features. Copyright © 2001 John Wiley & Sons, Ltd.
Essential role of the nonreducing terminal α‐mannosyl residues of the N‐linked carbohydrate chain of bovine zona pellucida glycoproteins in sperm‐egg binding
Authors: Amari S. , Yonezawa N. , Mitsui S. , Katsumata T. , Hamano S. , Kuwayama M. , Hashimoto Y. , Suzuki A. , Takeda Y. , Nakano M.
Published: September 2002

It has been proposed that mammalian sperm bind species‐specifically to carbohydrate chains of zona pellucida glycoproteins at fertilization. Although the sperm ligand carbohydrate chains have been characterized in mice and pigs, the existence of the ligands of other mammals remains unclear. In order to explore the bovine sperm ligand, two in vitro competition assay methods were applied. As a result, a high‐mannose‐type carbohydrate chain, Manα1‐6(Manα1‐3)Manα1‐6(Manα1‐3)Manβ1‐4GlcNAcβ1‐4GlcNAc, which is the major neutral chain in bovine egg zona glycoproteins, was shown to possess bovine sperm ligand activity. When nonreducing terminal α‐mannosyl residues were eliminated from the zona glycoproteins by α‐mannosidase digestion, the ligand activity was reduced, indicating that the α‐mannosyl residues play an essential role in bovine sperm‐egg binding. The number of sperm binding to eggs was reduced to about one‐half after fertilization. The ligand‐active high‐mannose‐type chain may be buried after fertilization, since its amount remains unchanged. Pretreatment of bovine sperm with the sperm ligand‐carbohydrate chain significantly inhibited penetration of the sperm into oocyte and the male pronucleus formation. Thus, a correlation between the sperm ligand activity and in vitro fertilization rate was observed. Mol. Reprod. Dev. 59:221–226, 2001. © 2001 Wiley‐Liss, Inc.
ADC mapping of the human optic nerve: Increased resolution, coverage, and reliability with CSF‐suppressed ZOOM‐EPI
Authors: Wheeler‐Kingshott Claudia A.M. , Parker Geoffrey J.M. , Symms Mark R. , Hickman Simon J. , Tofts Paul S. , Miller David H. , Barker Gareth J.
Published: September 2002

The mean apparent diffusion coefficient (ADC) of the human optic nerve (ON) has been quantified in vivo, and mean ADC maps are shown along the complete length of the nerve from the globe to the optic chiasm. The mean ADC, over the whole nerve, is shown to be 1058 × 10–6 mm2 s–1 (standard deviation (SD), over nine 3‐mm slices, 101×10–6 mm2 s–1; range (833–1178)×10–6 mm2 s–1). The robustness of the method relies on acquisition of high‐resolution coronal images of the ON using the ZOOM‐EPI technique, which makes use of a shortened echo train length for increased resolution with decreased susceptibility‐induced distortions. Suppression of the cerebrospinal fluid (CSF) and fat signals from tissues that surround the ON also helps successful identification and delineation of the nerve. Averaging of magnitude images is used to compensate for the inherently low signal‐to‐noise ratio (SNR) of the acquired images; the effects of the Rayleigh distributed noise in such images are allowed for during ADC calculations. Magn Reson Med 47:24–31, 2002. © 2002 Wiley‐Liss, Inc.
Regional magnetization transfer ratio changes in mild cognitive impairment
Authors: Kabani Noor Jehan , Sled John G. , Shuper Anita , Chertkow Howard
Published: September 2002

Reduction in temporal lobe volume is consistently found in dementia of Alzheimer's type (DAT). However, due to the lack of a consistent association between brain volume and cognitive decline in mild cognitive impairment (MCI), volumetric measures are not a reliable predictor for the progression of the disease. In our study, we hypothesized that changes in the magnetization transfer ratio (MTR) may reflect underlying brain pathology in the absence of quantifiable volumetric changes. Such a measure may be used as a predictor for abnormal cognitive decline in elderly subjects. The study was carried out on 15 normal elderly controls, 11 subjects with DAT, and 12 subjects with MCI. We used MTRs with magnetic resonance imaging (MRI) to detect tissue changes in the four lobes of each hemisphere, and compared that to the volumetric changes in the same regions. Our results indicate that the MTR of both temporal lobes is significantly reduced in subjects with MCI in the absence of significant volumetric changes. In comparison, DAT subjects have significantly reduced temporal lobe volumes and MTR. We conclude that changes in MTR have the potential to mark the progression of MCI to DAT, before volumetric changes are detected on conventional MRI scans.
Generalized SMASH imaging
Authors: Bydder Mark , Larkman David J. , Hajnal Joseph V.
Published: September 2002

A generalized parallel imaging method has been developed that uses coil profiles to generate missing k‐space lines. The proposed method is an extension of SMASH, which uses linear combinations of coil sensitivity profiles to synthesize spatial harmonics. In the generalized SMASH approach described here, coil sensitivity profiles are represented directly in the Fourier domain to provide a general description of the spatial properties of the coils. This removes restrictions imposed by conventional SMASH, so that the choice and position of the receiver coils can be made on the basis of sensitivity to the volume of interest rather than suitability for constructing spatial harmonics. Generalized SMASH also intrinsically allows the freedom to accommodate acquisitions with uniform or nonuniform k‐space sampling. The proposed method places SMASH on an equal footing with other parallel imaging techniques (SENSE and SPACE‐RIP), while combining strengths from each. The method was tested on phantom and human data and provides a robust method of data recovery. Magn Reson Med 47:160–170, 2002. © 2002 Wiley‐Liss, Inc.
Assessment of hepatic perfusion parameters with dynamic MRI
Authors: Materne R. , Smith A.M. , Peeters F. , Dehoux J.P. , Keyeux A. , Horsmans Y. , Van Beers B.E.
Published: September 2002

Quantification of hepatic perfusion parameters greatly contributes to the assessment of liver function. The purpose of this study was to describe and validate the use of dynamic MRI for the noninvasive assessment of hepatic perfusion parameters. The signal from a fast T1‐weighted spoiled gradient‐echo sequence preceded by a nonslice‐selective 90° pulse and a spoiler gradient was calibrated in vitro with tubes filled with various gadolinium concentrations. Dynamic images of the liver were obtained after intravenous bolus administration of 0.05 mmol/kg of Gd‐DOTA in rabbits with normal liver function. Hepatic, aortic, and portal venous signal intensities were converted to Gd‐DOTA concentrations according to the in vitro calibration curve and fitted with a dual‐input one‐compartmental model. With MRI, hepatic blood flow was 100 ± 35 mL min‐1 100 mL‐1, the arterial fraction 24 ± 11%, the distribution volume 13.0 ± 3.7%, and the mean transit time 8.9 ± 4.1 sec. A linear relationship was observed between perfusion values obtained with MRI and with radiolabeled microspheres (r = 0.93 for hepatic blood flow [P < 0.001], r = 0.79 for arterial blood flow [P = 0.01], and r = 0.91 for portal blood flow [P < 0.001]). Our results indicate that hepatic perfusion parameters can be assessed with dynamic MRI and compartmental modeling. Magn Reson Med 47:135–142, 2002. © 2002 Wiley‐Liss, Inc.