bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efferent ductules of the fan‐throated lizardSitana ponticerianaCuvier: light and transmission electron microscopy study
Authors: Akbarsha Mohammad A. , Kadalmani Balamuthu , Tamilarasan Veeramuthu 
Published: June 2007

AbstractLight microscopy histology of efferent ductules and the ultrastructural organization of their epithelium were studied in the fan‐throated lizardSitana ponticerianaCuvier. The ductules of this lizard are extra‐testicular and arise from an extra‐testicular rete testis. A major portion of the ductules is intra‐epididymal and occupies the cephalic end of the epididymis. The ductules differentiate histologically into proximal and distal portions. The epithelium is formed of two major tall columnar cell types, the non‐ciliated and ciliated, and one minor cell type, the basal cells. Dark cells were also identified. The non‐ciliated cells possess microvilli towards the luminal end, tubular coated pits at the bases of the microvilli, coated vesicles in the apical cytoplasm and multivesicular bodies, lysosomes and mitochondria in the supranuclear and perinuclear cytoplasm, which reflects their role in the uptake of the material they are processing. These cells also participate in spermiophagy. The ciliated cells reflect their role in mixing the luminal content and/or its transport to the distal parts of the male tract. The lizard efferent ductules share many features in common with those of mammals and a crocodile and several other features with birds and a turtle. Spermiophagy by the efferent ductules is reported here for the first time in a reptile.
An algorithm for managing the failure of external beam radiotherapy in prostate cancer
Authors: Dudderidge Tim , Payne Heather , Emberton Mark 
Published: June 2007

OBJECTIVETo present a management algorithm for men with prostate cancer recurring after external beam radiotherapy (EBRT), based on a review of published reports, to assist clinicians in identifying men who are suitable for salvage therapy and to help them to decide which type of salvage treatment is most likely to confer the desired outcome with the minimum of harm.METHODSMen with radiorecurrent prostate cancer require special consideration; they tend to be older, have more comorbidity and have worse disease than their contemporaries having primary treatment. Salvage treatment is compromised by the irradiated pelvis, resulting in increased treatment toxicity. Using the Pubmed database and reference lists of key articles, we identified studies relating to the management of radiorecurrent prostate cancer; the findings were incorporated into a management algorithm and summary table of treatments.RESULTSThe American Society for Therapeutic Radiology and Oncology criteria, which define biochemical failure has now been superseded by the Phoenix definition (nadir prostate‐specific antigen [PSA] plus 2 ng/mL). Biochemical follow‐up after EBRT should be 3‐monthly until the PSA level has reached a stable nadir after withdrawing androgen suppression. Contrast‐enhanced dynamic magnetic resonance imaging (MRI) is an accurate tool and can be used for both the diagnosis and staging of patients with prostate cancer, in conjunction with prostate biopsies. Prostate biopsies should only be considered >2 years after EBRT to avoid false‐positive results. In addition to MRI, high‐risk cases being considered for salvage therapy should be considered for laparoscopic lymph‐node dissection to exclude micrometastases. Deferred androgen suppression, laparoscopic or open radical prostatectomy, cryotherapy and high‐intensity focused ultrasound all seem reasonable salvage treatment approaches.CONCLUSIONThrough improved methods of detection, including frequent PSA measurements, modern imaging and carefully obtained biopsies, those with radiorecurrent disease can be identified before their disease has spread. Rigorous staging will exclude those with micrometastases. The minimally invasive salvage therapies seem to offer an advantage over salvage surgery to patients in whom the benefits and harms are so finely balanced.
Differences in the rate of lymph node invasion in men with clinically localized prostate cancer might be related to the continent of origin
Authors: Briganti Alberto , Shariat Shahrokh F. , Chun Felix K.‐H. , Hutterer Georg C. , Roehrborn Claus G. , Gallina Andrea , Rigatti Patrizio , Valiquette Luc , Montorsi Francesco , Karakiewicz Pierre I. 
Published: June 2007

OBJECTIVETo test whether the rate of lymph node invasion (LNI) differs between patients treated with radical prostatectomy (RP) at a European or a North American centre.PATIENTS AND METHODSIn all, 1385 men had RP with bilateral lymphadenectomy for clinically localized prostate cancer (587 from Dallas, Texas and 798 from Milan, Italy). Univariate and multivariate analyses focused on the association between the continent of origin and the rate of LNI, after controlling for prostate‐specific antigen (PSA) level, clinical stage, biopsy Gleason sum and the number of examined and removed lymph nodes.RESULTSEuropean men had higher PSA levels (9.1 vs 7.8 ng/mL), a higher proportion of palpable cancers (44.5 vs 32.8%), more nodes removed (mean 14.9 vs 7.8) and a higher rate of LNI (9.0% vs 1.2%; all differences P < 0.001). In multivariate analyses that controlled for PSA level and clinical variables, European men had an 8.9‐fold higher risk of LNI (P < 0.001) than their counterparts from the USA. Among preoperative variables, the continent of origin was the third most informative predictor of LNI (67.5%), after biopsy Gleason sum (74.3%) and the number of examined lymph nodes (71.0%), and improved the ability to predict LNI by 4.7%.CONCLUSIONMen treated at a European centre had a 7.3–8.9‐fold higher rate of LNI, despite adjusting for all clinical and pathological variables. It remains to be shown what predisposes European men to a higher rate of LNI.
Size evolution in island lizards
Authors: Meiri Shai 
Published: June 2007

ABSTRACTAim The island rule, small animal gigantism and large animal dwarfism on islands, is a topic of much recent debate. While size evolution of insular lizards has been widely studied, whether or not they follow the island rule has never been investigated. I examined whether lizards show patterns consistent with the island rule.Location Islands worldwide.Methods I used literature data on the sizes of island–mainland population pairs in 59 species of lizards, spanning the entire size range of the group, and tested whether small insular lizards are larger than their mainland conspecifics and large insular lizards are smaller. I examined the influence of island area, island isolation, and dietary preferences on lizard size evolution.Results Using mean snout–vent length as an index of body size, I found that small lizards on islands become smaller than their mainland conspecifics, while large ones become larger still, opposite to predictions of the island rule. This was especially strong in carnivorous lizards; omnivorous and herbivorous species showed a pattern consistent with the island rule but this result was not statistically significant. No trends consistent with the island rule were found when maximum snout–vent length was used. Island area had, at best, a weak effect on body size. Using maximum snout–vent length as an index of body size resulted in most lizard populations appearing to be dwarfed on islands, but no such pattern was revealed when mean snout–vent length was used as a size index.Main conclusions I suggest that lizard body size is mostly influenced by resource availability, with large size allowing some lizard populations to exploit resources that are unavailable on the mainland. Lizards do not follow the island rule. Maximum snout–vent length may be biased by sampling effort, which should be taken into account when one uses this size index.
What determines conformity to Bergmann's rule?
Authors: Meiri Shai , Yom‐Tov Yoram , Geffen Eli 
Published: June 2007

ABSTRACTAim  Bergmann's rule, the tendency of body size within species in bird and mammal populations to be positively correlated with latitude, is among the best known biogeographical generalizations. The factors behind such clines, however, are not well understood. Here we use a large data base of 79 mammalian carnivore species to examine the factors affecting latitudinal size clines.Location  Worldwide.Methods  We measured the skulls and teeth of carnivores in natural history museums, and calculated the amount of variation in size explained by latitude, supplementing our measurements with published data. We examined the effects of a number of variables on the tendency to show latitudinal clines.Results  We found that geographical range and latitudinal extent are strongly related to size clines. Minimum temperatures across the range, net primary productivity and habitat diversity also have some, albeit much less, influence.Main conclusions  We suggest that species with large geographical ranges are likely to encounter significant heterogeneity in those factors that influence body size, and are thus likely to exhibit size clines. However, the key factors that determine body size may not always operate along a latitudinal (or other geographical) cline, but be spatially linked to patches in the species range. One such important factor is likely to be food availability, which we show is a strong predictor of size in the brown bear (Ursus arctos) but is not associated with a latitudinal cline. We argue that the spatial distribution of key resources within the species range constitutes a significant predictor of carnivore body size.
Quercitol links the physiology, taxonomy and evolution of 279 eucalypt species
Authors: Merchant Andrew , Ladiges Pauline Y. , Adams Mark A. 
Published: June 2007

ABSTRACTAim  Increasing aridity over geological time‐scales has driven a high degree of speciation within the Eucalyptus group in Australia. Isolation of gene pools by climatic and edaphic conditions and high rates of out‐crossing have given rise to a large diversity of adaptive traits. Among these traits, adaptations of cellular biochemistry are likely to be significant in preserving cellular function during arid conditions. The aim of this study was to determine the quantitative and qualitative distribution of soluble carbohydrates and polyols in Eucalyptus.Location  Australia.Methods  We sampled 279 of the 700+ documented eucalypts (in the three genera comprising the eucalypts: Angophora Cav., Corymbia Hill & Johnson and Eucalyptus L’Hér.) and analysed leaf tissues for the occurrence of low‐molecular‐weight carbohydrates and polyols.Results  We have uncovered a discrete pattern in concentration of quercitol (a cyclitol) that correlates strongly with the current taxonomic classification based on both morphology and DNA sequencing. We also uncovered a further and stronger correlation between the presence of quercitol in leaf tissues and a reduced growth (mallee) form.Main conclusions  These findings, together with the chemical properties of quercitol, suggest that we have uncovered a chemical marker of structural adaptations to arid conditions, thus providing a putative, broad‐scale functional link to adaptation to aridity.
Selection of plants for roles in phytoremediation: the importance of glucosylation
Authors: Brazier‐Hicks Melissa , Edwards Lesley A. , Edwards Robert 
Published: June 2007

SummaryOver‐expression and transposon mutagenesis in root cultures of Arabidopsis thaliana demonstrated the importance of the family 1 glycosyltransferase UGT72B1 in catalysing the N‐glucosylation of the persistent pollutant 3,4‐dichloroaniline (DCA). In phytotoxicity studies with DCA in seedlings, over‐expression of UGT72B1 enhanced sensitivity, whereas the knockouts were more resistant than the controls. In contrast, manipulating the expression of UGT72B1 had no effect on the O‐glucosylation, or toxicity, of chlorophenols. When N‐glucosylation was disrupted in plants, radioactivity derived from [14C]‐DCA became covalently bound into high molecular weight insoluble material, principally associated with the lignin fraction. This suggested that insolubilization into stable cell wall components represented a more effective mechanism of DCA detoxification than the formation of N‐glycosidic conjugates. A screen of plants used in remediation, identified low levels of N‐glucosyltransferase activity in switchgrass and high activities in reed canary grass. When incubated with [14C]‐DCA, reed canary grass plants accumulated soluble N‐glycosides of DCA, whereas switchgrass formed insoluble residues. Consistent with the results obtained in studies with Arabidopsis, phytotoxicity trials with DCA demonstrated that switchgrass was more tolerant than reed canary grass. Our studies provide a new biochemical basis for selecting plants for useful remediating traits towards specific classes of pollutants.
Evolutionary origins of obesity
Authors: Bellisari A. 
Published: June 2007

SummaryAlthough it appeared relatively suddenly, the current obesity epidemic – largely manifest in industrialized societies but now spreading to the rest of the world – is the result of interaction between human biology and human culture over the long period of human evolution. As mammals and primates, humans have the capacity to store body fat when opportunities to consume excess energy arise. But during the millions of years of human evolution such opportunities were rare and transient. More commonly ancestral hominins and modern humans were confronted with food scarcity and had to engage in high levels of physical activity. In tandem with encephalization, humans evolved elaborate and complex genetic and physiological systems to protect against starvation and defend stored body fat. They also devised technological aids for increasing energy consumption and reducing physical effort. In the last century, industrialization provided access to great quantities of mass‐produced, high‐calorie foods and many labour‐saving and transportation devices, virtually abolishing starvation and heavy manual work. In the modern obesogenic environment, individuals possessing the appropriate combination of ancestral energy‐conserving genes are at greater risk for overweight and obesity and associated chronic diseases.
The Working Curve and Commodity Storage under Backwardation
Authors: Carter Colin A. , Giha Cesar L. Revoredo 
Published: June 2007

AbstractThere remains controversy over whether the empirical curve relating intertemporal commodity price spreads and stocks, originally drawn by Holbrook Working in 1933 (i.e., the Working curve), is a valid stylized fact in commodity markets. The core of the controversy is the portion of the curve representing commodity stocks under backwardation. In this article we analyze the original data used by Working, plus more disaggregated numbers. We find that the Working curve is indeed valid. The diversity of stockholders and different stockholding motives most likely explain the empirical Working curve relationship.
Credence Good Labeling: The Efficiency and Distributional Implications of Several Policy Approaches
Authors: Roe Brian , Sheldon Ian 
Published: June 2007

AbstractA model of vertical product differentiation is used to analyze the labeling of credence goods, focusing on the manner by which quality is communicated. The results indicate that firms prefer private labeling options. In addition, firms may hire private certifiers as well as paying for mandated government labels when the government's quality benchmark substantially deviates from firms' private quality choices. The average consumer prefers a mandatory, discrete label with a high‐quality standard while poor consumers prefer a mandatory, discrete label with a low standard.
Deriving a Flexible Mixed Demand System: The Normalized Quadratic Model
Authors: Moschini GianCarlo , Rizzi Pier Luigi 
Published: June 2007

AbstractThis article deals with the specification of a locally flexible and theory‐consistent system of mixed demand functions, a framework that allows for a rich set of possibilities about what is assumed as exogenous in a demand model. A coherent mixed demand system is derived by using the restricted expenditure function typically studied in the related area of rationed demands. The method is implemented by a new normalized quadratic (NQ) parameterization of the restricted expenditure function. The resulting NQ mixed demand system is illustrated with an application to a nine‐good model of the Italian demand for vegetables.
Adapting the Optimal Job Search Model for Active Labour Market Policy
Authors: Boys Richard J. , Dolton Peter J. , Walker Neil R. 
Published: June 2007

SummaryThe structural theoretical framework for the analysis of duration of unemployment has been the optimal job search model. Recent advances in computational techniques in Bayesian inference now facilitate the analysis of incomplete data sets and the recovery of structural model parameters. The paper uses these methods on a UK data set of the long-term unemployed to illustrate how the optimal job search model can be adapted to model the effects of an active labour market policy. Without such an adaptation our conclusion is that the simple optimal job search model may not fit empirical unemployment data and could thus lead to a misspecified econometric model and incorrect parameter estimates.
Statistical Issues in First-In-Man Studies
Authors: Senn Stephen , Amin Dipti , Bailey Rosemary A. , Bird Sheila M. , Bogacka Barbara , Colman Peter , Garrett Andrew , Grieve Andrew , Lachmann Peter 
Published: June 2007

PrefaceIn March 2006 a first-in-man trial took place using healthy volunteers involving the use of monoclonal antibodies. Within hours the subjects had suffered such adverse effects that they were admitted to intensive care at Northwick Park Hospital. In April 2006 the Secretary of State for Health announced the appointment of Professor (now Sir) Gordon Duff, who chairs the UK's Commission on Human Medicines, to chair a scientific expert group on phase 1 clinical trials. The group reported on December 7th, 2006 ( Expert Scientific Group on Clinical Trials, 2006a). Clinical trials have a well-established regulatory basis both in the UK and worldwide. Trials have to be approved by the regulatory authority and are subject to a detailed protocol concerning, among other things, the study design and statistical analyses that will form the basis of the evaluation. In fact, a cornerstone of the regulatory framework is the statistical theory and methods that underpin clinical trials. As a result, the Royal Statistical Society established an expert group of its own to look in detail at the statistical issues that might be relevant to first-in-man studies. The group mainly comprised senior Fellows of the Society who had expert knowledge of the theory and application of statistics in clinical trials. However, the group also included an expert immunologist and clinicians to ensure that the interface between statistics and clinical disciplines was not overlooked. In addition, expert representation was sought from Statisticians in the Pharmaceutical Industry (PSI), an organization with which the Royal Statistical Society has very close links. The output from the Society's expert group is contained in this report. It makes a number of recommendations directed towards the statistical aspects of clinical trials. As such it complements the report by Professor Duff's group and will, I trust, contribute to a safer framework for first-in-man trials in the future. Tim Holt (President, Royal Statistical Society)
The Teaching of Statistics in Uk Universities
Authors: Smith T. M. F. , Staetsky L. 
Published: June 2007

SummaryThe project on the teaching of statistics in UK universities has two phases. In phase 1 various data sources are explored and the Directory of Academic Statisticians is identified as the most reliable source of data on statistics teaching staff. The number of staff in core mathematical science groups peaked in 1996 and has declined since then. The decline is related to research assessment exercise score. Phase 2 is a survey of university groups that identify with the discipline of statistics within the mathematical sciences and which are the key groups for determining the future supply of statisticians. These groups can be categorized as strong, marginal or weak, depending on their recent history and perceived prospects. This categorization is used to make projections of staff numbers in 2010. A decline of between 7% and 22% is expected. The position in medical statistics is stable. Conclusions are drawn in the final section on the basis of the survey returns and the analysis of the Directory of Academic Statisticians data.
Marital Disruption and Economic Well-Being: a Comparative Analysis
Authors: Aassve Arnstein , Betti Gianni , Mazzuco Stefano , Mencarini Letizia 
Published: June 2007

SummaryThough there is a considerable literature concerned with the economic consequences of marital breakdown, there is still substantial disagreement in terms of its magnitude. One of the major problems underlying this debate is how economic well-being is defined. We implement several measures of well-being of monetary and multidimensional nature by using data from the European Community Household Panel. Another issue in this literature concerns selection bias of divorcing couples. We tackle this issue by using a propensity score matching technique combined with a difference-in-differences estimator. Results confirm the importance of the definition of well-being. We find a strong gender bias when using monetary measures but a considerably lower bias, and for some countries non-existent, when using non-monetary indices.