bluuebunny/crossref_metadata_2025 huggingface dataset:
Alligator aromatase cDNA sequence and its expression in embryos at male and female incubation temperatures
Authors: Gabriel Willow N. , Blumberg Bruce , Sutton Stacy , Place Allen R. , Lance Valentine A.
Published: August 2002

In all species of crocodilians, sex is determined not by genetic mechanisms, but by the temperature at which the egg is incubated. In the American alligator (Alligator mississippiensis) the thermosensitive period (TSP) for sex determination is a 7‐ to 10‐day window within stages 21–24 of development, around the middle third of the incubation period. Treating embryos with estrogen during the TSP produces female offspring, even at male incubation temperatures. Conversely, blocking embryonic estrogen synthesis at female‐inducing temperature prevents development of the female phenotype. Therefore, it has been suggested that estrogen plays a role in determination of sex in the alligator. Estrogen is produced from an androgen substrate by cytochrome P450 aromatase (CYP19). If estrogen plays a critical role in sex determination, there should be differences in aromatase expression between embryos at male‐ and female‐producing temperatures during the TSP. Therefore, to address this question, we cloned and characterized the alligator CYP19 cDNA. Based on the sequence information, a quantitative kinetic reverse transcriptase–polymerase chain reaction (TaqMan) assay was designed to measure expression of the alligator aromatase gene in RNA extracted from the gonadal and brain regions of alligator embryos incubated at male‐ or female‐producing temperatures from prior to the TSP through hatching. Aromatase expression was detected in the brain region from the earliest stage tested (stage 20) through hatching. The hypothalamus had significantly higher expression than the forebrain or hindbrain in both male and female embryos. Expression was not significantly different in the gonadal region between embryos at male and female temperatures until after the TSP, when there was a dramatic increase in expression at female temperature. These data indicate that aromatase expression and, thus, estrogen production, are not the initial trigger for sex determination but play an essential role in ovarian differentiation in the alligator. J. Exp. Zool. 290:439–448, 2001. © 2001 Wiley‐Liss, Inc.
Uterine epithelial‐sperm interaction, endometrial cycle and sperm storage in the terminal zone of the oviducal gland in the placental smoothhound,Mustelus canis
Authors: Hamlett William C. , Musick John A. , Hysell Christopher K. , Sever David M.
Published: August 2002

The fate of spermatozoa deposited within the female reproductive tract has been described in the smoothhound,Mustelus canis. Evidence of uterine epithelial‐sperm interaction is presented, as well as documentation of sperm storage specifically in the terminal zone of the oviducal gland. Sperm fate is correlated with morphology of the endometrial cycle and specificity of storage in the oviducal gland. The endometrium ofM. canisundergoes dramatic tissue remodeling associated with gestation. In females harboring fertilized ova or preimplantation yolk‐reliant embryos, the uterine epithelium is simple cuboidal with mucous droplets for lubrication. The presence of the embryo elicits a response from the uterus, which becomes modified for nutrient and respiratory exchange into vascular uterine attachment sites that abut the distal aspect of the yolk sac. Areas of the uterus adjacent to the uterine attachment sites are termed paraplacental sites. Uterine attachment sites are simple squamous while the paraplacental epithelium is simple columnar. Paraplacental cells have basal metachromatic vesicles and a dense array of apical cytoplasmic filaments. Immediately postpartum the uterine attachment sites, now termed uterine or placental scars, begin to remodel to a mucous epithelium for the next gestational cycle. Paraplacental cells slough off the apical filamentous portion, and sperm become embedded in the epithelium. Bundled sperm occur throughout gestation in the terminal zone of the oviducal gland. Sperm are not embedded in the terminal zone epithelium as in the uterus. Following sperm release from the uterus, the paraplacental epithelium reverts to a mucous epithelium for the next reproductive cycle. Fertilization is presumed to occur in the anterior oviduct above the oviducal gland. The physiological mechanisms that mediate sperm‐uterus attachment, release, and storage in the terminal zone of the oviducal gland are currently under investigation.J. Exp. Zool. 292:129–144, 2002. © 2002 Wiley‐Liss, Inc.
Scales of governance and environmental justice for adaptation and mitigation of climate change
Authors: Adger W.Neil
Published: August 2002

Global climate change is a significant challenge to structures of governance at all temporal and spatial scales, particularly in the area of managing natural resources. Advances in understanding of the nature of observed and future climate change has led to a realization that significant future impacts are inevitable and increased efforts towards understanding the process of adaptation to the threatened impacts are required. This paper examines the issue of scale of governance relevant for adaptation. The UN Framework Convention on Climate Change is the primary mechanism for co‐ordinating international action on the threat of global climate change. The Convention process perceives adaptation as a further rationale for international transfers, in this case to compensate for and prepare for potential or realised impacts. This approach can be justified by recourse to the idea that enhancing sustainable development will enhance adaptive capacity and that planned activities are a key part of overall adaptation. But many adaptations to climate change will be spontaneous actions to perceived and actual risks in the environment. Thus institutional and economic parameters determine the underlying vulnerability and adaptive capacity of societies. I therefore argue that an understanding of adaptation processes allows interventions and planned adaptations at the most appropriate scales. I illustrate these arguments with reference to adaptation in agriculture and outline the insights from interdisciplinary development studies that can inform the climate change debates. Copyright © 2001 John Wiley & Sons, Ltd.
Ultrastructure of the embryonic snake skin and putative role of histidine in the differentiation of the shedding complex
Authors: Alibardi Lorenzo
Published: August 2002

The morphogenesis and ultrastructure of the epidermis of snake embryos were studied at progressive stages of development through hatching to determine the time and modality of differentiation of the shedding complex. Scales form as symmetric epidermal bumps that become slanted and eventually very overlapped. During the asymmetrization of the bumps, the basal cells of the forming outer surface of the scale become columnar, as in an epidermal placode, and accumulate glycogen. Small dermal condensations are sometimes seen and probably represent primordia of the axial dense dermis of the growing tip of scales. Deep, dense, and superficial loose dermal regions are formed when the epidermis is bilayered (periderm and basal epidermis) and undifferentiated. Glycogen and lipids decrease from basal cells to differentiating suprabasal cells. On the outer scale surface, beneath the peridermis, a layer containing dense granules and sparse 25–30‐nm thick coarse filaments is formed. The underlying clear layer does not contain keratohyalin‐like granules but has a rich cytoskeleton of intermediate filaments. Small denticles are formed and they interdigitate with the oberhautchen spinulae formed underneath. On the inner scale surface the clear layer contains dense granules, coarse filaments, and does not form denticles with the aspinulated oberhautchen. On the inner side surface the oberhautchen only forms occasional spinulae. The sloughing of the periderm and embryonic epidermis takes place in ovo 5–6 days before hatching. There follow beta‐, mesos‐, and alpha‐layers, not yet mature before hatching. No resting period is present but a new generation is immediately produced so that at 6–10 h posthatching an inner generation and a new shedding complex are forming beneath the outer generation. The first shedding complex differentiates 10–11 days before hatching. In hatchlings 6–10 h old, tritiated histidine is taken up in the epidermis 4 h after injection and is found mainly in the shedding complex, especially in the apposed membranes of the clear layer and oberhautchen cells. This indicates that a histidine‐rich protein is produced in preparation for shedding, as previously seen in lizard epidermis. The second shedding (first posthatching) takes place at 7–9 days posthatching. It is suggested that the shedding complex in lepidosaurian reptiles has evolved after the production of a histidine‐rich protein and of a beta‐keratin layer beneath the former alpha‐layer. J. Morphol. 251:149–168, 2002. © 2002 Wiley‐Liss, Inc.
Morphometry ofMacaca mulattaforelimb. II. Fiber‐type composition in shoulder and elbow muscles
Authors: Singh Kan , Melis Ellen H. , Richmond Frances J.R. , Scott Stephen H.
Published: August 2002

The present study examined the fiber‐type proportions of 22 muscles spanning the shoulder and/or elbow joints of threeMacaca mulatta. Fibers were classified as one of three types: fast‐glycolytic (FG), fast‐oxidative‐glycolytic (FOG), or slow‐oxidative (SO). In most muscles, the FG fibers predominated, but proportions ranged from 25–67% in different muscles. SO fibers were less abundant except in a few deep, small muscles where they comprised as much as 56% of the fibers. Cross‐sectional area (CSA) of the three fiber types was measured in six different muscles. FG fibers tended to be the largest, whereas SO fibers were the smallest. While fiber‐type size was not always consistent between muscles, the relative size of FG fibers was generally larger than FOG and SO fibers within the same muscle. When fiber CSA was taken into consideration, FG fibers were found to comprise over 50% of the muscle's CSA in almost all muscles. J. Morphol. 251:323–332, 2002. © 2002 Wiley‐Liss, Inc.
Quantitative analysis of MRI signal abnormalities of brain white matter with high reproducibility and accuracy
Authors: Wei Xingchang , Warfield Simon K. , Zou Kelly H. , Wu Ying , Li Xiaoming , Guimond Alexandre , Mugler John P. , Benson Randall R. , Wolfson Leslie , Weiner Howard L. , Guttmann Charles R.G.
Published: August 2002

Purpose

To assess the reproducibility and accuracy compared to radiologists of three automated segmentation pipelines for quantitative magnetic resonance imaging (MRI) measurement of brain white matter signal abnormalities (WMSA).

Materials and Methods

WMSA segmentation was performed on pairs of whole brain scans from 20 patients with multiple sclerosis (MS) and 10 older subjects who were positioned and imaged twice within 30 minutes. Radiologist outlines of WMSA on 20 sections from 16 patients were compared with the corresponding results of each segmentation method.

Results

The segmentation method combining expectation‐maximization (EM) tissue segmentation, template‐driven segmentation (TDS), and partial volume effect correction (PVEC) demonstrated the highest accuracy (the absolute value of the Z‐score was 0.99 for both groups of subjects), as well as high interscan reproducibility (repeatability coefficient was 0.68 mL in MS patients and 1.49 mL in aging subjects).

Conclusion

The addition of TDS to the EM segmentation and PVEC algorithms significantly improved the accuracy of WMSA volume measurements, while also improving measurement reproducibility. J. Magn. Reson. Imaging 2002;15:203–209. © 2002 Wiley‐Liss, Inc.
MRI monitoring of the thermal ablation of tissue: Effects of long exposure times
Authors: McDannold Nathan , Hynynen Kullervo , Jolesz Ferenc
Published: August 2002

MRI‐derived thermometry based on the temperature‐dependence of the proton resonant frequency (PRF) is extremely sensitive to changes in tissue unrelated to temperature changes, including tissue swelling. This study investigated the maximum amount of time that this phase‐subtraction‐based method can be used to accurately monitor temperature changes in vivo. Long‐duration focused ultrasound sonications were delivered in rabbit thigh muscle with a phased‐array transducer, and the time that tissue swelling began was monitored. Tissue swelling began to occur at about one minute. The temperature correlated well with an implanted thermocouple up to this time. After this time, severe artifacts in the phase‐difference maps were observed. The thermal dose model predicted the extent of tissue damage well for subsequent one minute sonications. These results will have implications for MRI guidance of thermal therapies with long exposure times. J. Magn. Reson. Imaging 2001;13:421–427. © 2001 Wiley‐Liss, Inc.
Potential heating effect in the gravid uterus during MR HASTE imaging
Authors: Levine D. , Zuo C. , Faro C.B. , Chen Q.
Published: August 2002

Our purpose was to evaluate if temperature changes occur in maternal or fetal tissues during HASTE imaging. Methods: Pregnant pigs were scanned with the HASTE technique, and temperatures were measured with phase maps and temperature probes inserted into the amniotic fluid and fetal brain. Results: Fiberoptic probes showed that no heating occurred in fetal tissues or amniotic fluid during HASTE imaging. Conclusion: Our current HASTE protocols do not deposit a significant amount of heat in the gravid uterus. J. Magn. Reson. Imaging 2001;13:856–861. © 2001 Wiley‐Liss, Inc.
In vitro validation of MR measurements of arterial pulse‐wave velocity in the presence of reflected waves
Authors: Stevanov Maja , Baruthio Joseph , Gounot Daniel , Grucker Daniel
Published: August 2002

A magnetic resonance imaging projective velocity encoding sequence was used to determine the pulse‐wave velocity in an artery model. To this end, a well‐defined flow phantom simulating flow propagation in large arteries was used. In order to validate the measurement method in the presence of large reflected waves, these were deliberately created in the phantom. The projective sequence was applied to two measurement sites and the wave velocity was determined from the spatial and temporal separations of the foot of the velocity waveform. A theoretical model describing reflection and attenuation phenomena was compared with experimental velocity waveforms. The model showed that reflections and attenuation can explain the important changes in velocity waveforms. The model also confirmed that in the presence of reflecting waves, the foot of the waveform can be used as a characteristic point for measurements through changes in the waveform. J. Magn. Reson. Imaging 2001;14:120–127. © 2001 Wiley‐Liss, Inc.
Improved in‐gel approaches to generate peptide maps of integral membrane proteins with matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Montfort Bart A. van , Canas Benito , Duurkens Ria , Godovac‐Zimmermann Jasminka , Robillard George T.
Published: August 2002

This paper reports studies of in‐gel digestion procedures to generate MALDI‐MS peptide maps of integral membrane proteins. The methods were developed for the membrane domain of the mannitol permease of E. coli. In‐gel digestion of this domain with trypsin, followed by extraction of the peptides from the gel, yields only 44% sequence coverage. Since lysines and arginines are seldomly found in the membrane‐spanning regions, complete tryptic cleavage will generate large hydrophobic fragments, many of which are poorly soluble and most likely contribute to the low sequence coverage. Addition of the detergent octyl‐β‐glucopyranoside (OBG), at 0.1% concentration, to the extraction solvent increases the total number of peptides detected to at least 85% of the total protein sequence. OBG facilitates the recovery of hydrophobic peptides when they are SpeedVac dried during the extraction procedure. Many of the newly recovered peptides are partial cleavage products. This seems to be advantageous since it generates hydrophobic fragments with a hydrophilic solubilizing part. In‐gel CNBr cleavage resulted in 5–10‐fold more intense spectra, 83% sequence coverage, fully cleaved fragments and no effect of OBG. In contrast to tryptic cleavage sites, the CNBr cleavage sites are found in transmembrane segments; cleavage at these sites generates smaller hydrophobic fragments, which are more soluble and do not need OBG. With the results of both cleavages, a complete sequence coverage of the membrane domain of the mannitol permease of E. coli is obtained without the necessity of using HPLC separation. The protocols were applied to two other integral membrane proteins, which confirmed the general applicability of CNBr cleavage and the observed effects of OBG in peptide recovery after tryptic digestion. Copyright © 2002 John Wiley & Sons, Ltd.
Differential IgM response to conformational and linear epitopes of parvovirus B19 VP1 and VP2 structural proteins
Authors: Manaresi Elisabetta , Zuffi Elisa , Gallinella Giorgio , Gentilomi Giovanna , Zerbini Marialuisa , Musiani Monica
Published: August 2002

The IgM immune response against conformational and linear epitopes of B19 structural proteins VP1 and VP2 was examined in serum samples with a suspect B19 infection to determine the most suitable antigen for use in IgM detection and also to evaluate a possible relationship between the course of B19 infection and the presence of epitope type‐specific IgM. The detection of IgM against conformational epitopes was performed by ELISA using undenatured VP1 and VP2 antigens whereas the detection of IgM against linear epitopes was performed by Western blot assays using denatured VP1 and VP2. IgM immune response against VP1 conformational epitopes appeared dominant, being detected in all serum samples positive for specific IgM, whereas IgM against VP2 linear antigen were found less frequently, being identified in less than half of the B19 IgM positive sera. In the examination of the course of infection, IgM against VP1 conformational epitopes appeared in the active phase of B19 infection at the same time and with the same frequency as IgM anti VP2 conformational epitopes and anti linear VP1 epitopes. IgM against VP1 conformational epitopes were seen to be long‐lasting because in the recent phase of infection they were still present when other specific IgM were absent. During the active phase of B19 infection, IgM against VP2 linear epitopes were less frequently found than other specific IgM and in the recent phase they underwent a rapid temporal diminution. The data demonstrate that a sensitive B19 IgM test needs to be performed in diagnostic laboratories by ELISA using conformational B19 antigens; Western blot assays can be used only as confirmatory tests using VP1 linear antigens. J. Med. Virol. 64:67–73, 2001. © 2001 Wiley‐Liss, Inc.
Brain remodeling due to neuronal and astrocytic proliferation after controlled cortical injury in mice
Authors: Kernie Steven G. , Erwin Trent M. , Parada Luis F.
Published: August 2002

The persistence of neural stem cells into adulthood has been an area of intense investigation in recent years. There is limited knowledge about how an acquired brain injury might affect the ability of neural precursor cells to proliferate and repopulate injured areas. In the present study we utilize a controlled cortical impact model of traumatic brain injury in adult mice and subsequent BrdU labeling to demonstrate that there is significant proliferation of neural precursors in response to traumatic brain injury in areas both proximal and distal to the injury site. The fate of the proximal proliferation is almost exclusively astrocytic at 60‐days post injury and demonstrates that newly generated cells make up much of the astrogliotic scar. Moreover, in areas more distal from the injury site, neurogenesis occurs within the granular layer of the dentate gyrus at a level more than five‐fold greater than in controls. These data demonstrate that neural proliferation plays key roles in the remodeling that occurs after traumatic brain injury and suggests a mechanism as to how functional recovery after traumatic brain injuries continues to occur long after the injury itself. J. Neurosci. Res. 66:317–326, 2001. © 2001 Wiley‐Liss, Inc.
Regulation and subcellular localization of the microtubule‐destabilizing stathmin family phosphoproteins in cortical neurons
Authors: Gavet Olivier , El Messari Saïd , Ozon Sylvie , Sobel André
Published: August 2002

Stathmin is a ubiquitous cytosolic phosphoprotein, preferentially expressed in the nervous system, and the generic element of a protein family that includes the neural‐specific proteins SCG10, SCLIP, and RB3 and its splice variants, RB3′ and RB3′′. All phosphoproteins of the family share with stathmin its tubulin binding and microtubule (MT)‐destabilizing activities. To understand better the specific roles of these proteins in neuronal cells, we performed a comparative study of their expression, regulation, and intracellular distribution in embryonic cortical neurons in culture. We found that stathmin is highly expressed (∼0.25% of total proteins) and uniformly present in the various neuronal compartments (cell body, dendrites, axon, growth cones). It appeared mainly unphosphorylated or weakly phosphorylated on one site, and antisera to specific phosphorylated sites (serines 16, 25, or 38) did not reveal a differential regulation of its phosphorylation among neuronal cell compartments. However, they revealed a subpopulation of cells in which stathmin was highly phosphorylated on serine 16, possibly by CaM kinase II also active in a similar subpopulation. The other proteins of the stathmin family are expressed about 100‐fold less than stathmin in partially distinct neuronal populations, RB3 being detected in only about 20% of neurons in culture. In contrast to stathmin, they are each mostly concentrated at the Golgi apparatus and are also present along dendrites and axons, including growth cones. Altogether, our results suggest that the different members of the stathmin family have complementary, at least partially distinct functions in neuronal cell regulation, in particular in relation to MT dynamics. © 2002 Wiley‐Liss, Inc.
TrkB dimerization during development of the prefrontal cortex of the macaque
Authors: Ohira Koji , Shimizu Keiko , Hayashi Motoharu
Published: August 2002

To date, two subtypes of TrkB, a BDNF receptor, have been described. One is full‐length TrkB (TK+), which has a tyrosine kinase‐containing intracellular domain. The other is truncated TrkB (TK−), which has a short intracellular domain lacking the tyrosine kinase. In this study, we investigated the dimerization of TrkB subtypes in the developing monkey prefrontal cortex by means of cross‐linking. At embryonic day 120, the TK+/TK+ and the 100 kDa/100 kDa homodimers were observed with BDNF stimulation. At the newborn stage, the TK+/TK+ and the TK−/TK− homodimers were observed with BDNF stimulation. At the adult stage, the TK−/TK− homodimer and the TK+/TK− heterodimer were formed by BDNF stimulation. The levels of all dimers increased in proportion to the concentration of BDNF. Moreover, the dimers were clearly formed within 5 min of treatment with BDNF. BDNF and NT‐4/5 induced the dimers, whereas NT‐3 formed slight dimers but NGF did not. Furthermore, anti‐BDNF antibody inhibited the TrkB dimerization. Moreover, the intercellular binding proteins of TrkB were not cross‐linked by BS3. Therefore, these results suggest that the change in dimerization among TrkB subtypes occurs during development of the monkey prefrontal cortex. J. Neurosci. Res. 65:463–469, 2001. © 2001 Wiley‐Liss, Inc.
To vote or not to vote: abstaining from voting in union representation elections
Authors: Hepburn C. Gail , Barling Julian
Published: August 2002

We conducted two studies addressing abstaining from voting in union representation elections. In Study 1 of a faculty representation election, we showed that compared to voters abstainers possessed less extreme work and union attitudes, believed less in the ability of their vote to affect the election outcomes, and were less involved in the election (e.g., less interested, felt less responsibility to vote). To assess the practical utility of these findings, Study 2 used vignettes in a 2 (traditional bread‐and‐butter issues) × 2 (emerging issues related to fairness) × 2 (voting instrumentality) × 2 (responsibility to vote) experimental manipulation. Results showed that the likelihood of abstaining is reduced when efforts to emphasize the responsibility to vote are presented together with information on both traditional and emerging issues. The two studies show why people abstain from voting in union representation elections, and suggest how abstaining might be reduced. Conceptual implications, practical interventions and research directions raised by the two studies are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Attachment, decay, and social network
Authors: Burt Ronald S.
Published: August 2002

To study decay in attachment to an organization, I analyse data on women who obtained an MBA from the University of Chicago's Graduate School of Business (GSB). I measure attachment in terms of network embedding: an alumna is attached to the GSB to the extent that people close to her graduated from the GSB. Behavioral data corroborate the network data in that alumnae measured to be more attached are more likely to have joined an alumni club and made a financial contribution to the school. The hypothesis is that alumnae attachment will decay over time, more slowly when the school is deeply embedded in an alumna's network, more quickly when disruptive events compete for the alumna's time and energy. As expected, attachment declines across the years after graduation (linearly for the first 20 years to about half its initial level), and decay is inhibited when connections with GSB graduates are embedded in stable relations of family, work, or long‐term friendship. Decay is remarkably robust to events after graduation (which account for only 2 per cent of explained variance in attachment). In other words, an alumna's attachment today was largely determined while she was in school. The results should be of practical value to people who design programmes to build personal attachment to organizations, and of theoretical interest to scholars who study such connections. Copyright © 2001 John Wiley & Sons, Ltd.
Mental health outcomes of job stress among Chinese teachers: role of stress resource factors and burnout
Authors: Tang Catherine So‐Kum , Au Wing‐Tung , Schwarzer Ralf , Schmitz Gerdamarie
Published: August 2002

This study examined the mental health outcomes of job stress among Chinese teachers in Hong Kong. A total of 269 Chinese teachers participated in Study 1 which provided cross‐sectional data regarding the associations among stress resource factors, burnout, and negative mental health. Study 2 was a six‐month longitudinal study which aimed to establish the direction of the associations among the hypothesized variables across two time points with a separate sample of 61 Chinese secondary school teachers. Results of the structural equation modelling analyses on the cross‐sectional data at T1 showed that stress resource factors of self‐efficacy and proactive attitude were negatively related to burnout, which in turn had a direct effect on negative mental health. Stress resource factors were also directly linked to mental health status of teachers. Results of similar analyses on the longitudinal data at T2 further indicated that burnout at T1 had a direct impact on burnout at T2, which in turn had a direct effect on negative mental health at T2. Findings and limitations of the study were discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Principal sequence pattern analysis: a new approach to classifying the evolution of atmospheric systems
Authors: Compagnucci Rosa H. , Araneo Diego , Canziani Pablo O.
Published: August 2002

A new eigentechnique approach, Principal Sequence Pattern Analysis (PSPA), is introduced for the analysis of spatial pattern sequence, as an extension of the traditional Principal Component Analysis set in the T‐Mode. In this setting, the variables are sequences of k spatial fields of a given meteorological variable. PSPA is described and applied to a sample of 256 consecutive daily 1000 hPa geopotential height fields. The results of the application of the technique to 5‐day sequences demonstrate the advantages of this procedure in identifying field pattern sequences, thereby allowing the determination of the evolution and development of the systems, together with cyclogenesis and anticyclogenesis processes.

In order to complete the study, the more traditional Extended Empirical Orthogonal Function (EEOF) analysis, which is the S‐mode equivalent of the PSPA, was applied to the same dataset. For EEOF, it was not possible to identify any real sequences that could correspond to the sequences of patterns yielded by the EEOF. Furthermore, the explained variance distribution in the EEOF was significantly different from that obtained with PSPA. Conversely, the PSPA approach allowed for the identification of the sequences corresponding to those sequences observed in the data. Using diagrams of the squares of the component loadings values, as a function of time, the study of the times of occurrence of dominant field characteristics was also possible. In other words, successful determination of periods where the basic flow was dominant and times when strongly perturbed transient events with a significant meridional component occurred, was facilitated by PSPA. Copyright © 2001 Royal Meteorological Society
Modelling summer extreme rainfall over the Korean peninsula using Wakeby distribution
Authors: Park Jeong‐Soo , Jung Hyun‐Sook , Kim Rae‐Seon , Oh Jai‐Ho
Published: August 2002

Attempts to use the Wakeby distribution (WAD) with the method of L‐moments estimates (L‐ME), on the summer extreme rainfall data (time series of annual maximum of daily and 2‐day precipitation) at 61 gauging stations over South Korea have been made to obtain reliable quantile estimates for several return periods. The 90% confidence intervals for the quantiles determined by WAD have been obtained by the bootstrap resampling technique. The isopluvial maps of estimated design values corresponding to selected return periods have been presented. Copyright © 2001 Royal Meteorological Society
Investigating the link between early season Caribbean rainfall and the El Niño + 1 year
Authors: Anthony Chen A. , Taylor Michael A.
Published: August 2002

The Caribbean rainfall season is best characterized by its bimodal nature, with an initial peak in May–June and a second more prominent one in September–October. This allows for a convenient division into an early and a late rainfall season. In this study we examine the rainfall patterns of the early rainfall season (mid April to July) for links with El Niño–Southern Oscillation (ENSO) events. Whereas traditionally ENSO events have been identified with dry conditions during the later Caribbean rainfall season, recent research suggests a second signal that manifests itself as a wet early rainfall season of the year of ENSO decline (the El Niño + 1 year). Two leading empirical orthogonal function modes of early season Caribbean rainfall are examined for evidence of this. Strong correlations are shown to exist between the first mode and wintertime equatorial Pacific anomalies. The first mode explains nearly half of the early season variability. The idea that the wintertime Pacific anomalies alter the early Caribbean rainfall season via the warm spring sea surface temperature anomalies they induce in the north tropical Atlantic is also investigated. An atmospheric general circulation model is also used to show that, when warm/cold anomalies exist across the north tropical Atlantic, this results in a large‐scale atmospheric circulation that is more/less favourable to rainfall production over the Caribbean. Copyright © 2002 Royal Meteorological Society.
A 13C NMR spectral examination of α- and β-carbon signal peak heights in some disubstituted arylporphyrins
Authors: SHAW SUSANNA J. , SHANMUGATHASAN SAKTHITHARAN , CLARKE OLIVER J. , BOYLE ROSS W. , OSBORNE ALAN G. , EDWARDS CHRISTINE
Published: August 2002

A 13 C NMR spectral study of 29 arylporphyrin derivatives is presented. In all of the tetrasubstituted and trisubstituted compounds examined the α- and β-carbons exhibited the expected broadened signals. In complete contrast, the diphenylporphyrins all showed sharp α- and β-carbon peaks which facilitated structural confirmation. These observations have been correlated with differing tautomeric exchange rates.
Interactions of tetracationic mercury(II), cadmium(II) and lead(II) porphyrins with DNA and their effects on DNA cleavage
Authors: NYARKO ELVIS , TABATA MASAAKI
Published: August 2002

The effects of tetrakis(1-methylpyridinium-4-yl)porphyrinatomercury(II) [ Hg ( TMPyP )]4+(6) along with [ Pb ( TMPyP )]4+(7), [ Cd ( TMPyP )]4+(8), and [ H2( TMPyP )]4+(1) (free base porphyrin) on DNA cleavage by Haemophilus aegyptius (HaeIII) have been studied using gel electrophoresis, UV-vis absorption spectroscopy, and circular dichroism (CD) spectroscopy. The gel electrophoresis results indicate that in the absence of 6, HaeIII restriction enzyme could not cleave plasmid DNA at a low concentration of 0.2 units μl-1after 1 h incubation at 37 °C. However, DNA cleavage occurred in the presence of 6 at the concentrations of 1.0 × 10-6and 1.0 × 10-7M and 0.2 units μl-1of HaeIII under the same conditions. In addition, acceleration of DNA cleavage occurred at a higher concentration of HaeIII (0.4 units μl-1) in the presence of a wider concentration range of 6 from 1.0 × 10-5to 1.0 × 10-7M . 8, 7, and 1 could not enhance DNA cleavage in the presence of HaeIII (0.2 units μl-1). However, when the concentration of HaeIII was increased to 0.4 units μl-1, only 8 inhibited DNA cleavage by HaeIII at higher concentrations (1.0 × 10-5-10-6M ) whereas 6, 7, and 1 did not. The UV-vis and CD spectroscopic results indicate that these porphyrins interact differently with DNA based on their binding modes. 6 enhanced DNA cleavage due to the synergistic effect of the Hg2+ions and the free base porphyrin 1 that dissociated from the mercury(II) porphyrin complex upon binding to DNA which resulted in the enhanced transformation of the DNA conformation from the original B-form to a Z-like conformation, while 8 inhibited HaeIII activity at higher concentrations and 7 and 1 neither enhanced nor inhibited DNA cleavage. A mechanism for this phenomenon is suggested.
Colour fixation in ripe olives. Effects of type of iron salt and other processing factors
Authors: García Pedro , Brenes Manuel , Romero Concepción , Garrido Antonio
Published: August 2002

A detailed study has been made of the colour fixation stage of ripe olive processing. The effects of the degree of iron oxidation and the colour‐fixing liquid on iron availability have been investigated and an explanation is given for the greater effectiveness of ferrous salts compared to ferric salts. Likewise, a 24 factorial design was used to study the influence on olive colour of the pH of the aeration solution, the type of colour‐fixing liquid, the type of ferrous salt and the aeration system. The data were analysed by multivariate and univariate analysis of variance (MANOVA/ANOVA), the best results being obtained with low pH (4.0), tap water, ferrous lactate and no aeration during the first 3 h of immersion in the colour‐fixing solution. These results can be explained by the iron availability averages having been altered by differences in the concentration of organic matter, the pH of the solution and the diffusion of iron into the olive flesh. The results can be used to reduce iron residues in ripe olives.

© 2001 Society of Chemical Industry
The impact of ecotourism on livelihood and natural resource management in Eselenkei, Amboseli Ecosystem, Kenya
Authors: Ogutu Z. A.
Published: August 2002

This paper presents the impact of ecotourism on livelihood and natural resource management in the periphery of Amboseli Biosphere Reserve in Kenya. Ecotourism initiatives that have been introduced by Porini Ecotourism, a private investor, are benefiting Eselenkei Group Ranch in terms of income, improved infrastructure, employment opportunities and exposure. Over US$5000 is received annually as land rent, gate fee and bed charges. Twenty‐six Maasai men are employed for the upkeep of project facilities. The community's capacity to facilitate resource‐related conflicts has improved following support from development institutions. An expanding livelihood base is reducing local vulnerability to disaster and people–wildlife conflicts. The numbers of resident wildlife species in the conservation area have increased due to regeneration of woody species and reduced frequency of livestock.

Despite the achievements, ecotourism is threatened by cultivation. The latter is jeopardizing conservation efforts, as the area frequented by wildlife is being lost and people–wildlife conflicts intensified. Another dilemma is that the Eselenkei community is not effectively participating in ecotourism a situation that is associated with inadequate management and negotiation skills in the group ranch committee. The latter requires leadership and microenterprise management skills if earnings from ecotourism are to be effectively invested in alternative sources of livelihood, to reduce current and potential conflicts. There is also need to build the community's capacity for the promotion of activities that compliment ecotourism. Frequent breakdown of community boreholes lead to dependence on the conservation area for water during prolonged drought, intensifying conflicts between livestock and wildlife.

Referring to low‐impact nature‐based tourism packages that benefit local communities and the national government while helping to conserve the resource base (Kenya Wildlife Service (KWS), unpublished report, 2001).

Copyright © 2002 John Wiley & Sons, Ltd.
Laser treatment of congenital facial port‐wine stains: Long‐term efficacy and complication in Chinese patients
Authors: Ho Wai Sun , Chan Henry H , Ying Shun Yuen , Chan Pik Chu
Published: August 2002

Background and Objective

Pulsed dye laser (585 nm, 450 μs) and variable pulse width frequency doubled Nd:YAG 532 nm laser have been proven to be effective in treating vascular lesions in Caucasians especially in facial port‐wine stain. Their roles in dark‐skinned Asian have not been determined. The objective of this study was to assess the long‐term outcome and complication of laser treatment of congenital facial port‐wine stain in Chinese patients retrospectively.

Study Design/Materials and Methods

Files of all patients with port‐wine stains who had received laser treatment in a major regional laser center in a 5‐year period were reviewed. Chinese patients with congenital facial port‐wine stains were recruited for the study. They were called back for questionnaire assessment of their degree of clearance and clinical examination for treatment complication. Detail demographics, result of questionnaire and clinical examination were entered into a database and statistical analyses were conducted where applicable.

Results

One hundred and seven patients with congenital facial port‐wine stain were recruited for the study. Thirty‐six patients had received PDL treatment, 40 patients had VP532 treatment and 31 patients had been treated by both laser systems. A total of 665 treatment sessions had been performed with an average of 6.1 ± 2.8 sessions (range 3–12). They had been followed‐up from 2 to 5 years with a mean period of 3.4 ± 1.1 years. Over 60% of patients had more than 25% of clearing and the majority of patients (41.1%) had 25–50% of clearing. Less than one‐quarter of patients (23%) experienced a clearing more than 50% and no patient had complete clearing. There was no significant difference in the subjective assessment of clearing between patients that had different forms of laser treatments. No patient had recurrence of pigmentation after treatment. Fourteen percent of patients experienced complications and the majority of them had pigmentary changes. Sex, age, number of treatment session, and type of laser machine used were not related to a higher complication rate using the multiple regression analysis.

Conclusions

Chinese patients were less responsive to laser treatment with higher complication rate. In addition, more treatment sessions were required to achieve a maximum clearing. However, most of our patients were satisfied with laser treatment (Patient Satisfaction Score = 7.25). Dark‐skinned patients should not be excluded from laser therapy provided that treatment expectations and risks are fully discussed. Lasers Surg. Med. 30:44–47, 2002. © 2002 Wiley‐Liss, Inc.
PHOTOFRIN‐mediated photodynamic therapy for treatment of early stage oral cavity and laryngeal malignancies*
Authors: Schweitzer Vanessa Gayl
Published: August 2002

Background and Objective

To determine the efficacy of PHOTOFRIN‐mediated photodynamic therapy (PDT) for treatment of diffuse “field cancerization” of the oral cavity and Cis‐T2N0M0 squamous cell carcinoma (SqCCa) of the larynx in patients not amenable or that have failed conventional head and neck treatment.

Study Design/Materials and Methods

Over the past 15 years 10 patients with early stage Tis‐T2N0M0 SqCCa of the oral cavity and oropharynx and 10 patients with Tis‐T2N0M0 SqCCa of the larynx were treated. Intravenous PHOTOFRIN (porfimer sodium) (dose 2.0 mg/kg) was administered outpatient, followed 48–60 hours later by intraoperative light photoactivation at 630 nm via fiberoptic microlens (ML) delivery (surgical light dose, 50–100 J/cm2) and/or cylindrical diffuser (CD) delivery (80–100 J/cm).

Results

Complete responses (CRs) (follow up 6 months–9 years) were achieved in eight of 10 patients with diffuse field cancerization of the oral cavity. CRs (follow up 6 months–8 years) were achieved in eight of 10 patients with superficial laryngeal cancer obviating the need for total laryngectomy in previously treated radiation therapy patients.

Conclusion

PHOTOFRIN‐mediated PDT provides a surgical oncologic modality for potentially curative treatment of early stage oral cavity and laryngeal malignancies with minimal side effects, absence of systemic toxicity, preservation of oral function and voice quality, with multiple drug administration, and laser light retreatment capability. Lasers Surg. Med. 29:305–313, 2001. © 2001 Wiley‐Liss, Inc.
Determinants of mail‐survey response: Survey design factors and respondent factors
Authors: Helgeson James G. , Voss Kevin E. , Terpening Willbann D.
Published: August 2002

With the use of a hierarchy‐of‐effects model, the decision to complete a mail survey was modeled as a process moving through several stages. A set of variables thought to influence the survey‐completion decision process was examined. These variables include survey design factors, which were manipulated by the researchers, and respondent factors, such as attitudinal and personal constructs. Based on the research findings, the hierarchy‐of‐effects model is an appropriate way to model the mail‐survey‐response process. The data indicate that among the survey design factors included in the study, the monetary incentive had the most effect on the decision process, with a pervasive impact throughout the process. Importantly, respondent factors such as attitude toward research were of critical importance in moving respondents through the survey‐response process. Research into the response‐rate phenomenon is likely to benefit by considering how both survey design and respondent factors affect specific stages of the response process and enhance participation in surveys. © 2002 Wiley Periodicals, Inc.
Quinoxaline 1,4‐dioxides: Hypoxia‐selective therapeutic agents
Authors: Diab‐Assef Mona , Haddadin Makhluf J. , Yared Pierre , Assaad Chafika , Gali‐Muhtasib Hala U.
Published: August 2002

A problem that confronts clinicians in the treatment of cancer is the resistance of hypoxic tumors to chemotherapy and radiation therapy. Thus, the development of new drugs that are toxic to hypoxic cells found in solid tumors is an important objective for effective anticancer chemotherapy. We recently showed that the heterocyclic aromatic N‐oxides, quinoxaline 1,4‐dioxides (QdNOs), are cytotoxic to tumor cells cultured under hypoxia. In this study, we evaluated the hypoxia‐selective toxicity of four diversely substituted QdNOs and determined their effect on the expression of hypoxia inducible factor (HIF) 1α in the human colon cancer cell line T‐84. The various QdNOs were found to possess a 50‐ to 100‐fold greater cytotoxicity to T‐84 cells cultured under hypoxia compared with oxia. Interestingly, the hypoxia cytotoxicity ratio (HCR), the ratio of equitoxic concentrations of the drug under aerobic/anoxic conditions, was highly structure related and depended on the nature of the substituents on the QdNO heterocycle. The most cytotoxic 2‐benzoyl‐3‐phenyl‐6,7‐dichloro derivative of QdNO (DCQ) was potent at a dose of 1 μM with an HCR of 100 and significantly reduced the levels of HIF‐1α transcript and protein. The 2‐benzoyl‐3‐phenyl derivative (BPQ) had a hypoxia potency of 20 μM and an HCR of 40. By contrast, the 2‐aceto‐3‐methyl and the 2,3‐tetramethylene (TMQ) derivatives of QdNO were much less cytotoxic under hypoxia (HCRs of 8.5 and 6.5, respectively) and reduced the expression of HIF‐1α mRNA to a much lesser extent. Because the nonchlorinated analogue BPQ did not demonstrate behavior similar to that of DCQ, we hypothesize that the C‐6, C‐7‐chlorine of DCQ might play a significant role in the selective hypoxic cytotoxicity of the drug. © 2002 Wiley‐Liss, Inc.
The probability and timing of price reversals in the property market
Authors: Partington Graham , Stevenson Max
Published: August 2002

In this paper, we develop models for estimating the time varying probability that there will be a price reversal in the property market. Knowledge of such price reversals may be helpful in forming property trading strategies, and providing confirming evidence of turning points in property cycles. Using an index from the UK property market, we obtain the time varying probabilities by estimating state transition rates. State transition rates are estimated for cases where the up‐state (a run of positive price changes) switches to the down‐state (price falls) and vice versa. We also estimate a model for absolute transitions, where we take no account of the direction of the state transition. The predictive power of our models is assessed using data from a holdout period. We find that the absolute transition model performs worse than separate state transition models for the up‐state and the down‐state. For these latter models, the more rapid the decline in the forecast probability of a run continuing beyond a certain time, the less likely it is that the run will actually continue. Further, the probability profiles provide a perfect rank ordering of the length of runs in the holdout period. This suggests that the probabilities could be used to predict whether a sequence of price rises or falls will be long‐ or short‐lived. Copyright © 2001 John Wiley & Sons, Ltd.
Parkinsonism after glycine‐derivate exposure
Authors: Barbosa Egberto R. , Leiros da Costa Maria D. , Bacheschi Luiz A. , Scaff Milberto , Leite Claudia C.
Published: August 2002

This 54‐year‐old man accidentally sprayed himself with the chemical agent glyphosate, a herbicide derived from the amino acid glycine. He developed disseminated skin lesions 6 hours after the accident. One month later, he developed a symmetrical parkinsonian syndrome. Two years after the initial exposure to glyphosate, magnetic resonance imaging revealed hyperintense signal in the globus pallidus and substantia nigra, bilaterally, on T2‐weighted images. Levodopa/benserazide 500/125 mg daily provided satisfactory clinical outcome.