bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling the effectiveness and risks of vaccination strategies to control classical swine fever epidemics
Authors: Backer Jantien A. , Hagenaars Thomas J. , van Roermund Herman J.W. , de Jong Mart C.M.
Published: December 2008

In a recent update of the Dutch contingency plan for controlling outbreaks of classical swine fever (CSF), emergency vaccination is preferred to large-scale pre-emptive culling. This policy change raised two questions: can emergency vaccination be as effective as pre-emptive culling, and what are the implications for showing freedom of infection? Here, we integrate quantitative information available on CSF virus transmission and vaccination effects into a stochastic mathematical model that describes the transmission dynamics at the level of animals, farms and livestock areas. This multilevel approach connects individual-level interventions to large-scale effects. Using this model, we compare the performance of five different control strategies applied to hypothetical CSF epidemics in The Netherlands and, for each of these strategies, we study the properties of three different screening scenarios to show freedom of infection. We find that vaccination in a ring of 2 km radius around a detected infection source is as effective as ring culling in a 1 km radius. Feasible screening scenarios, adapted to the use of emergency vaccination, can reduce the enhanced risks of (initially) undetected farm outbreaks by targeting vaccinated farms. Altogether, our results suggest that emergency vaccination against CSF can be equally effective and safe as pre-emptive culling.
Free light chains in plasma of patients with light chain amyloidosis and non‐amyloid light chain deposition disease. High proportion and heterogeneity of disulfide‐linked monoclonal free light chains as pathogenic features of amyloid disease
Authors: Kaplan Batia , Ramirez‐Alvarado Marina , Sikkink Laura , Golderman Sicilia , Dispenzieri Angela , Livneh Avi , Gallo Gloria
Published: December 2008

Immunoglobulin light chain amyloidosis (AL) and non‐amyloid light chain deposition disease (NALCDD) are different forms of protein aggregation disorders accompanied by a monoclonal gammopathy. Monoclonal free light chains (FLCs) are precursors of the pathological light chain tissue deposits that are fibrillar in AL and granular in NALCDD. However, direct biochemical examination of plasma FLC precursors, which would allow comparison and better understanding of these two diseases, is still lacking. In this study, we examined FLCs in plasma of patients with AL and NALCDD by employing separation on Sep‐PaK C18 cartridges, micro‐preparative electrophoresis, Western blotting and mass spectrometry. Comparative analysis of AL versus NALCDD and control plasma samples showed new evidence of increased level and heterogeneity of circulating disulfide‐bound FLC species in AL. In addition to full length monomers comprising the disulfide‐linked FLCs, the monoclonal disulfide‐bound FLC fragments were typically revealed in AL plasma. We hypothesized that enhanced disulfide binding of FLCs in AL interferes with their normal clearance and metabolism, which in turn might play a role in amyloid formation. The applied methods might be useful to diagnose or predict the pathological form of the disease and shed light on the mechanisms involved in light chain aggregation in tissues.
Loss of phosphorus from soil in semi‐arid northern Tanzania as a result of cropping: evidence from sequential extraction and 31P‐NMR spectroscopy
Authors: Solomon D. , Lehman N. J.
Published: December 2008

In semi‐arid northern Tanzania, the native woodland is being rapidly cleared and replaced by low input agriculture. This has resulted in pronounced environmental degradation, and in particular loss of phosphorus (P) from the soil. We have used sequential extraction and 31P‐NMR to investigate the effects of land use changes, i.e. native woodland, degraded woodland, cultivation for 3 and 15 years and homestead fields where manure was applied, on the amount and structural composition of P in this soil. Clearing and continuous cultivation reduced both organic and inorganic P in the soil. The difference in the amount of organic P from the bulk soil of the fields cultivated for 3 and 15 years was not statistically significant (P < 0.05), suggesting that most of the depletion in organic P occurred during the first 3 years of cultivation. By contrast, in the homesteads, there was much organic and inorganic P in the soil. The 31P‐NMR revealed that cultivation resulted in a 53% depletion of orthophosphate diester P, whereas only a 30% and 39% reduction of orthophosphate monoester P was found in the bulk soil after 3 and 15 years of cultivation, respectively. These results concur with the suggestion that diester P constitutes more easily mineralizable forms of organic P in soil than does monoester P. Our 31P‐NMR also showed that 70% of the inorganic orthophosphate P was depleted from the coarse and fine sand separates as a result of cultivation. The influence of clearing and subsequent cropping on the amount and forms of P was more pronounced in the coarse and fine sand than in the silt and clay, stressing the importance of particle size and chemical properties such as organic matter and oxides in the availability of P in this soil. Our results show that the current low input agricultural practice is not sustainable, and that practices must be developed to combat the ongoing degradation of the soil. A combined use of available organic materials such as animal manure with the judicious use of inorganic fertilizers can replenish the soil's fertility.
Transformation of organic matter from maize residues into labile and humic fractions of three European soils as revealed by 13C distribution and CPMAS‐NMR spectra
Authors: Spaccini R. , Piccolo A. , Haberhauer G. , Gerzabek M. H.
Published: December 2008

The dynamics of incorporation of fresh organic residues into the various fractions of soil organic matter have yet to be clarified in terms of chemical structures and mechanisms involved. We studied by 13C‐dilution analysis and CPMAS‐13C‐NMR spectroscopy the distribution of organic carbon from mixed or mulched maize residues into specific defined fractions such as carbohydrates and humic fractions isolated by selective extractants in a year‐long incubation of three European soils. The contents of carbohydrates in soil particle size fractions and relative δ13C values showed no retention of carbohydrates from maize but rather decomposition of those from native organic matter in the soil. By contrast, CPMAS‐13C‐NMR spectra of humic (HA) and fulvic acids (FA) extracted by alkaline solution generally indicated the transfer of maize C (mostly carbohydrates and peptides) into humic materials, whereas spectra of organic matter extracted with an acetone solution (HE) indicated solubilization of an aliphatic‐rich, hydrophobic fraction that seemed not to contain any C from maize. The abundance of 13C showed that all humic fractions behaved as a sink for C from maize residues but the FA fraction was related to the turnover of fresh organic matter more than the HA. Removal of hydrophobic components from incubated soils by acetone solution allowed a subsequent extraction of HA and, especially, FA still containing much C from maize. The combination of isotopic measurements and NMR spectra indicated that while hydrophilic compounds from maize were retained in HA and FA, hydrophobic components in the HE fraction had chemical features similar to those of humin. Our results show that the organic compounds released in soils by mineralization of fresh plant residues are stored mainly in the hydrophilic fraction of humic substances which are, in turn, stabilized against microbial degradation by the most hydrophobic humic matter. Our findings suggest that native soil humic substances contribute to the accumulation of new organic matter in soils.
Monazite chemistry: evidence for a prehistoric journey
Authors: Dawood Yehia H. , Abd El‐Naby Hamdy H.
Published: December 2008

The chemistry of monazite from the black sand deposits of northern Sinai beach suggests that pegmatites and granites of the Eastern Desert of Egypt are the most likely source rocks. The floods associated with the pluvial periods prevailed in Egypt during the Pleistocene were able to erode the source rocks and liberate heavy minerals including monazite. The mineral grains were moved through several wadis and tributaries to the River Nile. At the confluence sites, these heavy minerals were mixed with the Ethiopian and central African heavy mineral assemblages. The grains continued to move together downriver until being deposited in their current locations.
Review series on helminths, immune modulation and the hygiene hypothesis: Mechanisms underlying helminth modulation of dendritic cell function
Authors: Carvalho Lucas , Sun Jie , Kane Colleen , Marshall Fraser , Krawczyk Connie , Pearce Edward J.
Published: December 2008

Dendritic cells (DCs) play a central role in activating CD4 T (T helper, Th) cells. As a component of their response to pathogen‐associated stimuli, DCs produce cytokines and express surface molecules that provide important cues to modulate the effector functions of responding Th cells. Much is known of how DCs respond to, and influence immune response outcome to, bacterial and viral pathogens. However, relatively little is understood about how DCs respond to helminth parasites. This is an area of considerable interest since it impacts our understanding of the initiation of Th2 responses, which are stereotypically associated with helminth infections, and the regulation of allergic and autoimmune pathologies which evidence suggests are less severe or absent in individuals infected with helminths. This review attempts to summarize our understanding of the effects of helminth products on dendritic cell biology.
Review series on helminths, immune modulation and the hygiene hypothesis: Immunity against helminths and immunological phenomena in modern human populations: coevolutionary legacies?
Authors: Jackson Joseph A. , Friberg Ida M. , Little Susan , Bradley Janette E.
Published: December 2008

Although the molecules and cells involved in triggering immune responses against parasitic worms (helminths) remain enigmatic, research has continued to implicate expansions of T‐helper type 2 (Th2) cells and regulatory T‐helper (Treg) cells as a characteristic response to these organisms. An intimate association has also emerged between Th2 responses and wound‐healing functions. As helminth infections in humans are associated with a strong Th2/Treg immunoregulatory footprint (often termed a ‘modified Th2’ response), plausible links have been made to increased susceptibility to microbial pathogens in helminth‐infected populations in the tropics and to the breakdowns in immunological control (allergy and autoimmunity) that are increasing in frequency in helminth‐free developed countries. Removal of helminths and their anti‐inflammatory influence may also have hazards for populations exposed to infectious agents, such as malaria and influenza, whose worst effects are mediated by excessive inflammatory reactions. The patterns seen in the control of helminth immunity are discussed from an evolutionary perspective. Whilst an inability to correctly regulate the immune system in the absence of helminth infection might seem highly counter‐adaptive, the very ancient and pervasive relationship between vertebrates and helminths supports a view that immunological control networks have been selected to function within the context of a modified Th2 environment. The absence of immunoregulatory stimuli from helminths may therefore uncover maladaptations that were not previously exposed to selection.
Widespread mito‐nuclear discordance with evidence for introgressive hybridization and selective sweeps in Lycaeides
Authors: GOMPERT ZACHARIAH , FORISTER MATTHEW L. , FORDYCE JAMES A. , NICE CHRIS C.
Published: December 2008

We investigated the extent and potential cause(s) of mitochondrial introgression within the polytypic North American Lycaeides species complex (Lepidoptera). By comparing population genetic structure based on mitochondrial DNA (COI and COII) and nuclear DNA (251 polymorphic amplified fragment length polymorphism markers), we detected substantial mito‐nuclear discordance, primarily involving a single mitochondrial haplotype (h01), which is likely due to mitochondrial introgression between differentiated Lycaeides populations and/or species. We detected reduced mitochondrial genetic diversity relative to nuclear genetic diversity in populations where mitochondrial haplotype h01 occurs, suggesting that the spread of this haplotype was facilitated by selection. We found no evidence that haplotype h01 is associated with increased fitness (in terms of survival to eclosion, fresh adult weight, and adult longevity) in a polymorphic Lycaeides melissa population. However, we did find a positive association between mitochondrial haplotype h01 and infection by the endoparasitic bacterium Wolbachia in one out of three lineages tested. Linkage disequilibrium between mitochondrial haplotype h01 and Wolbachia infection status may have resulted in indirect selection favouring the spread of haplotype h01 in at least one lineage of North American Lycaeides. These results illustrate the potential for introgressive hybridization to produce substantial mito‐nuclear discordance and demonstrate that an individual's mitochondrial and nuclear genome may have strikingly different evolutionary histories resulting from non‐neutral processes and intrinsic differences in the inheritance and biology of these genomes.
Polymorphic MHC loci in an asexual fish, the amazon molly (Poecilia formosa; Poeciliidae)
Authors: SCHASCHL HELMUT , TOBLER MICHAEL , PLATH MARTIN , PENN DUSTIN J. , SCHLUPP INGO
Published: December 2008

Genes of the major histocompatibility complex (MHC) encode molecules that control immune recognition and are highly polymorphic in most vertebrates. The remarkable polymorphisms at MHC loci may be maintained by selection from parasites, sexual selection, or both. If asexual species show equal (or higher) levels of polymorphisms at MHC loci as sexual ones, this would mean that sexual selection is not necessary to explain the high levels of diversity at MHC loci. In this study, we surveyed the MHC diversity of the asexual amazon molly (Poecilia formosa) and one of its sexual ancestors, the sailfin molly (P. latipinna), which lives in the same habitat. We found that the asexual molly has polymorphic MHC loci despite its clonal reproduction, yet not as polymorphic as the sexual species. Although the nucleotide diversity was similar between the asexual and sexual species, the sexual species exhibited a greater genotypic diversity compared to the asexual one from the same habitats. Within‐genome diversity was similar for MHC class I loci, but for class IIB, the sexual species had higher diversity compared to the asexual — despite the hybrid origins and higher levels of heterozygosity at microsatellite loci in the asexual species. The level of positive selection appears to be similar between the two species, which suggests that these polymorphisms are maintained by selection. Thus, our findings do not allow us to rule out the sexual selection hypothesis for the evolution of MHC diversity, and although the sexual fish has higher levels of MHC‐diversity compared to the asexual species, this may be due to differences in demography, parasites, or other factors, rather than sexual selection.
Lineage diversification and historical demography of a sky island salamander,Plethodon ouachitae, from the Interior Highlands
Authors: SHEPARD DONALD B. , BURBRINK FRANK T.
Published: December 2008

Sky islands provide ideal opportunities for understanding how climatic changes associated with Pleistocene glacial cycles influenced species distributions, genetic diversification, and demography. The salamanderPlethodon ouachitaeis largely restricted to high‐elevation, mesic forest on six major mountains in the Ouachita Mountains. Because these mountains are separated by more xeric, low‐elevation valleys, the salamanders appear to be isolated on sky islands where gene flow among populations on different mountains may be restricted. We used DNA sequence data along with ecological niche modelling and coalescent simulations to test several hypotheses related to diversifications in sky island habitats. Our results revealed thatP. ouachitaeis composed of seven well‐supported lineages structured across six major mountains. The species originated during the Late Pliocene, and lineage diversification occurred during the Middle Pleistocene in a stepping stone fashion with a cyclical pattern of dispersal to a new mountain followed by isolation and divergence. Diversification occurred primarily on an east–west axis, which is likely related to the east–west orientation of the Ouachita Mountains and the more favourable cooler and wetter environmental conditions on north slopes compared to south‐facing slopes and valleys. All non‐genealogical coalescent methods failed to detect significant population expansion in any lineages. Bayesian skyline plots showed relatively stable population sizes over time, but indicated a slight to moderate amount of population growth in all lineages starting approximately 10 000–12 000 years ago. Our results provide new insight into sky island diversifications from a previously unstudied region, and further demonstrate that climatic changes during the Pleistocene had profound effects on lineage diversification and demography, especially in species from environmentally sensitive habitats in montane regions.
Phylogeographical analyses reveal global migration patterns of the barley scald pathogen Rhynchosporium secalis
Authors: ZAFFARANO PASCAL L. , MCDONALD BRUCE A. , LINDE CELESTE C.
Published: December 2008

A phylogeographical analysis of the scald pathogen Rhynchosporium secalis was conducted using nuclear DNA sequences from two neutral restriction fragment length polymorphism loci and the mating‐type idiomorphs. Approximately 500 isolates sampled from more than 60 field populations from five continents were analysed to infer migration patterns and the demographic history of the fungus. Migration rates among continents were generally low, consistent with earlier reports of significant population subdivision among continents. Northern Europe was mainly a source population for global migration. We hypothesize that the pathogen only recently moved out of its centre of origin, resulting in founder populations that are reproductively isolated due to the contemporary absence of long‐distance gene flow.
Extensive pollen flow in two ecologically contrasting populations of Populus trichocarpa
Authors: SLAVOV G. T. , LEONARDI S. , BURCZYK J. , ADAMS W. T. , STRAUSS S. H. , DIFAZIO S. P.
Published: December 2008

Pollen‐mediated gene flow was measured in two populations of black cottonwood using direct (paternity analysis) and indirect (correlated paternity) methods. The Marchel site was an area with an approximate radius of 250 m in a large continuous stand growing in a mesic habitat in western Oregon. In contrast, the Vinson site was an area with a radius of approximately 10 km and consisted of small, disjunct and isolated stands in the high desert of eastern Oregon. Pollen immigration was extensive in both populations, and was higher in the Marchel site (0.54 ± 0.02) than in the substantially larger and more isolated Vinson site (0.32 ± 0.02). Pollen pool differentiation among mothers was approximately five times stronger in the Vinson population (ΦFT = 0.253, N = 27 mothers) than in the Marchel population (ΦFT = 0.052, N = 5 mothers). Pollen dispersal was modelled using a mixed dispersal curve that incorporated pollen immigration. Predicted pollination frequencies generated based on this curve were substantially more accurate than those based on the widely used exponential power dispersal curve. Male neighbourhood sizes (sensu Wright 1946) estimated using paternity analysis and pollen pool differentiation were remarkably similar. They were three to five times smaller in the Vinson population, which reflected the substantial ecological and demographic differences between the two populations. When the same mathematical function was used, applying direct and indirect methods resulted in similar pollen dispersal curves, thus confirming the value of indirect methods as a viable lower‐cost alternative to paternity analysis.
Breeding system, colony and population structure in the weaver antOecophylla smaragdina
Authors: SCHLÜNS E.A. , WEGENER B.J. , SCHLÜNS H. , AZUMA N. , ROBSON S. K. A. , CROZIER R. H.
Published: December 2008

Weaver ants (Oecophylla smaragdina) are dominant ants in open forests from India, Australia, China and Southeast Asia, whose leaf nests are held together with larval silk. The species, together with its sole congenerO. longinoda, has been important in research on biological control, communication, territoriality and colony integration. Over most of the range, only one queen has been found per colony, but the occurrence of several queens per nest has been reported for the Australian Northern Territory. The number of males mating with each queen is little known. Here we report on the colony structure ofO. smaragdinausing published and new microsatellite markers. Worker genotype arrays reflect the occurrence of habitual polygyny (more than one queen per colony) in 18 colonies from Darwin, Northern Australia, with up to five queens inferred per colony. Monogyny (one queen per colony) with occasional polygyny was inferred for 14 colonies from Queensland, Australia, and 20 colonies from Java, Indonesia. Direct genotyping of the sperm carried by 77 Queensland queens and worker genotypic arrays of established colonies yielded similar results, indicating that less than half of the queens mate only once and some mate up to five times. Worker genotype arrays indicated that queens from Java and the Northern Territory also often mate with more than one male, but less often than those from Queensland. A strong isolation‐by‐distance effect was found for Queensland samples. The variation uncovered means thatO. smaragdinais a more versatile study system than previously supposed.
Characterization of IRX10 and IRX10‐like reveals an essential role in glucuronoxylan biosynthesis in Arabidopsis
Authors: Brown David M. , Zhang Zhinong , Stephens Elaine , Dupree Paul , Turner Simon R.
Published: December 2008

Xylan, the major hemicellulosic polysaccharide in Arabidopsis secondary cell walls, requires a number of glycosyltransferases (GT) to catalyse formation of the various glycosidic linkages found in the polymer. In this study, we characterized IRX10 and IRX10‐like (IRX10‐L), two highly homologous genes encoding members of the glycosyltransferase family 47 (GT47). T‐DNA insertions in IRX10 gave a mild irregular xylem (irx) phenotype consistent with a minor defect in secondary cell‐wall synthesis, whereas plants containing mutations in IRX10‐L showed no change. However, irx10 irx10‐L double mutant plants showed a much more severe irx and whole‐plant phenotype, suggesting considerable functional redundancy between these two genes. Detailed biochemical analysis of the irx10 irx10‐L double mutant showed a large reduction of xylan in the secondary cell walls, consistent with a specific defect in xylan biosynthesis. Furthermore, the irx10 irx10‐L mutant retains the unique oligosaccharide found at the reducing end of Arabidopsis xylan, but shows a severe reduction in β(1,4) xylosyltransferase activity. These characteristics are similar to those of irx9 and irx14, mutants that are believed to be defective in xylan chain elongation, and suggests that IRX10 and IRX10‐L also play a role in elongation of the xylan backbone.
A mutation in THERMOSENSITIVE MALE STERILE 1, encoding a heat shock protein with DnaJ and PDI domains, leads to thermosensitive gametophytic male sterility in Arabidopsis
Authors: Yang Ke‐Zhen , Xia Chuan , Liu Xiao‐Lei , Dou Xiao‐Ying , Wang Wei , Chen Li‐Qun , Zhang Xue‐Qin , Xie Li‐Fen , He Luyan , Ma Xuan , Ye De
Published: December 2008

In most flowering plant species, pollination and fertilization occur during the hot summer, so plants must have evolved a mechanism that ensures normal growth of their pollen tubes at high temperatures. Despite its importance to plant reproduction, little is known about the molecular basis of thermotolerance in pollen tubes. Here we report the identification and characterization of a novel Arabidopsis gene, THERMOSENSITIVE MALE STERILE 1 (TMS1), which plays an important role in thermotolerance of pollen tubes. TMS1 encodes a Hsp40‐homologous protein with a DnaJ domain and an a_ERdj5_C domain found in protein disulfide isomerases (PDI). Purified TMS1 expressed in Escherichia coli (BL21 DE3) had the reductive activity of PDI. TMS1 was expressed in pollen grains, pollen tubes and other vegetative tissues, including leaves, stems and roots. Heat shock treatment at 37°C increased its expression levels in growing pollen tubes as well as in vegetative tissues. A knockout mutation in TMS1 grown at 30°C had greatly retarded pollen tube growth in the transmitting tract, resulting in a significant reduction in male fertility. Our study suggests that TMS1 is required for thermotolerance of pollen tubes in Arabidopsis, possibly by functioning as a co‐molecular chaperone.
An introduction to chemokines and their roles in transfusion medicine
Authors: Davenport R. D.
Published: December 2008

Chemokines are a set of structurally related peptides that were first characterized as chemoattractants and have subsequently been shown to have many functions in homeostasis and pathophysiology. Diversity and redundancy of chemokine function is imparted by both selectivity and overlap in the specificity of chemokine receptors for their ligands. Chemokines have roles impacting transfusion medicine in haematopoiesis, haematologic malignancies, transfusion reactions, graft‐versus‐host disease, and viral infections. In haematopoietic cell transplantation, chemokines are active in mobilization and homing of progenitor cells, as well as mediating T‐cell recruitment in graft‐versus‐host disease. Platelets are rich source of chemokines that recruit and activate leucocytes during thrombosis. Important transfusion‐transmissible viruses such as cytomegalovirus and human immunodeficiency virus exploit chemokine receptors to evade host immunity. Chemokines may also have roles in the pathophysiology of haemolytic and non‐haemolytic transfusion reactions.
Metabolic and productive response to ruminal protein degradability in early lactation cows fed untreated or xylose‐treated soybean meal‐based diets
Authors: Jahani‐Moghadam M. , Amanlou H. , Nikkhah A.
Published: December 2008

Effects of different dietary rumen undegradable (RUP) to degradable (RDP) protein ratios on ruminal nutrient degradation, feed intake, blood metabolites and milk production were determined in early lactation cows. Four multiparous (43 ± 5 days in milk) and four primiparous (40 ± 6 days in milk) tie‐stall‐housed Holstein cows were used in a duplicated 4 × 4 Latin square design with four 21‐day periods. Each period had 14‐day of adaptation and 7‐day of sampling. Diets contained on a dry matter (DM) basis, 23.3% alfalfa hay, 20% corn silage and 56.7% concentrate. Cows were first offered alfalfa hay at 7:00, 15:00 and 23:00 hours, and 30 min after each alfalfa hay delivery were offered a mixture of corn silage and concentrate. Treatments were diets with RUP:RDP ratios of (i) 5.2:11.6 (control), (ii) 6.1:10.6, (iii) 7.1:9.5 and (iv) 8.1:8.5, on a dietary DM% basis. Different RUP:RDP ratios were obtained by partial and total replacement of untreated soybean meal (SBM) with xylose‐treated SBM (XSBM). In situ study using three rumen‐cannulated non‐lactating cows showed that DM and crude protein (CP) of SBM had greater rapidly degradable fractions. The potentially degradable fractions were degraded more slowly in XSBM. Treatment cows produced greater milk, protein, lactose, solids‐non‐fat and total solids than control cows. Increasing RUP:RDP reduced blood urea linearly. Feed costs dropped at RUP:RDP ratios of 6.1:10.6 and 7.1:9.5, but not at 8.1:8.5, compared with the 5.2:11.6 ratio. Intake of DM and CP, rumen pH, blood glucose, albumin and total protein, faecal and urine pH, changes in body weight and body condition score, and milk lactose and solids‐non‐fat percentages did not differ among treatments. Results provide evidence that increasing dietary RUP:RDP ratio from 5.2:11.6 to 7.1:9.5 optimizes nitrogen metabolism and milk production and reduces feed costs in early lactation cows. Reduced blood urea suggests reprodutive benefits.
SURGICAL HEURISTICS
Authors: Patkin Michael
Published: December 2008

Heuristics are rules of thumb. Rarely described in surgical or other publications, they are an essential part of safe and expert performance. This study translates such implicit or procedural knowledge into explicit or declarative knowledge, with a view to improving both training and retraining of surgeons in the steps of dissection. Tools used include ordinary observation accompanied by introspection, and study of operative videos. Validation of the value of such heuristics is yet to be achieved.
OTOLARYNGOLOGIC HEURISTICS: A RHINOLOGIC PERSPECTIVE
Authors: Weitzel Erik Kent , Floreani Steve , Wormald Peter‐John
Published: December 2008

Rhinological heuristics are adapted from common principles within the field of otolaryngology. The most important principle in achieving quality endoscopic sinus surgery is good haemostatic control of the surgical field. Once this is achieved, the surgeon can then begin advancing to other heuristic principles. Thinking one to two moves in advance allows the surgeon to take advantage of the many dually purposed instruments available. Learning to visualize buried structures by their subtle projections quickly follows. Finally, an ergonomically positioned surgeon with intricate anatomical knowledge of the sinonasal cavities permits a second surgeon to assist and greatly expand the limit of what is possible.
HEMITHYROIDECTOMY: A HEURISTICS PERSPECTIVE
Authors: Serpell Jonathan W. , Grodski Simon , Yeung Meei , Swann John , Kemp Sarah , Johnson William
Published: December 2008

Heuristics describe the multiple small steps required for successful surgery, which are often taken for granted, enabling key manoeuvres, their correct order and their timely performance. Successful hemithyroidectomy is dependent on correct siting of the incision; tension to allow elevation of sub‐platysmal flaps without damaging anterior jugular veins; strap muscle division with preservation of the ansa cervicalis; recognition of the importance of the sub‐sternothyroid plane; superior mobility of the thyroid lobe, involving freeing the superior strap muscle layer and dissection of the pyramidal lobe; division of the isthmus to assist anteromedial mobility; dissection of the lateral thyroid space to free the posterior ‘v’ lip of the superior pole; medial to lateral dissection of the avascular cricothyroid space with preservation of the external laryngeal nerve, prior to ligation of the superior thyroid vessels; anteromedial rotation of the thyroid lobe with elevation of any retrosternal component; capsular dissection of the inferior pole with preservation of vascularity of the inferior parathyroid gland; dissection of the thyroid lobe off the recurrent laryngeal nerve, especially above the inferior thyroid artery in the region of greatest risk to the nerve, the region of the ligament of Berry; preservation of a vascularized superior parathyroid gland; capsular dissection, creating windows between vessels enabling their precise control, thereby minimizing haemorrhage. This paper aims to emphasize these heuristic components of thyroidectomy.
Urothelial and incidental prostate carcinoma in prostates from cystoprostatectomies for bladder cancer: is there a relationship between urothelial and prostate cancer?
Authors: Barbisan Francesca , Mazzucchelli Roberta , Scarpelli Marina , Lopez‐Beltran Antonio , Cheng Liang , Kirkali Ziya , Montironi Rodolfo
Published: December 2008

OBJECTIVE

To determine the incidence and features of urothelial carcinoma (UC) involving the prostate (UCP) and of prostate adenocarcinoma (PA) in radical cystoprostatectomy (RCP) for bladder cancer.

PATIENTS AND METHODS

The whole‐mount prostate sections of 248 RCP consecutively examined from 1995 to 2007 were reviewed to determine the incidence and features of UCP and PA. UCP was separately evaluated for UC originating from the urethra and peri‐urethral ducts (PUC) and for direct extension of bladder UC.

RESULTS

There was UCP in 94 (37.9%) of 248 patients, whereas PUC was present in 78 (31.5%). UC in situ and noninvasive papillary PUC was present in 42 (53.9%) of the 78, whereas stromal invasion was present in 36 (46.1%). Direct extension of UC from the bladder only was present in 16 (6.5%) patients. PA was present in 123 (49.6%) of 248 patients; 96 (78.1%) were in the peripheral zone. In 107 patients (87%) the Gleason score was ≤6; 96 (78.1%) were pT2a, with a lower frequency in other pT categories. The margins were negative in 96.7% of cases. All patients were pN0 for PA; in 116 (95.1%) the volume was <0.5 mL. Of the 123 patients with incidental prostate cancer, 100 cancers (81.3%) were considered clinically insignificant. UCP coexisted with PA in 43 (17.3%) of 248 patients, whereas PUC and PA occurred together in the same prostate in 32 (12.9%). Direct extension of UC from the bladder and PA occurred together in the same prostate in 11 (4.4%) patients.

CONCLUSIONS

UC involving the prostate and PA are present in most RCP specimens. UC can arise from extension of trigonal or bladder‐neck tumours, proximal prostate ducts/urethra, or from cell implantation from manipulation of vesical neoplasms. The frequent high coincidence of prostate and bladder cancer can be explained by a common pathway of carcinogenesis.
Cancer‐specific and non‐cancer‐related mortality rates in European patients with T1a and T1b renal cell carcinoma
Authors: Zini Laurent , Patard Jean‐Jacques , Capitanio Umberto , Crepel Maxime , De La Taille Alexandre , Tostain Jacques , Ficarra Vincenzo , Bernhard Jean‐Christophe , Ferrière Jean‐Marie , Pfister Christian , Villers Arnauld , Montorsi Francesco , Karakiewicz Pierre I.
Published: December 2008

OBJECTIVE

To examine cancer‐specific and non‐cancer‐related mortality rates in 451 patients with T1a–bN0M0 renal cell carcinoma (RCC) treated with either radical or partial nephrectomy (RN or PN) in Europe.

PATIENTS AND METHODS

Between 1987 and 2007, 451 patients with T1a–bN0M0 RCC were treated for histologically confirmed RCC with RN or PN at one of seven participating European institutions. The preoperative American Society of Anesthesiology (ASA) score was available for all patients and was used to control for baseline comorbidities. The preoperative glomerular filtration rate (GFR) was estimated using the Modification of Diet in Renal Disease study group equation. We used univariate and multivariate competing‐risks regression analyses to test the effect of the ASA score, GFR, T stage (T1a vs T1b) and nephrectomy type (RN or PN) on RCC‐specific mortality and non‐RCC‐related mortality.

RESULTS

In patients with T1a–b RCC cancer‐ specific mortality was unaffected by stage, nephrectomy type or GFR. Conversely, non‐RCC‐related mortality was strongly affected by the ASA score and GFR. Unlike in a previous report, nephrectomy type did not affect non‐RCC‐related mortality. This lack of significance relative to RN may stem from the relatively high rate of PN use in the present series.

CONCLUSION

PN or RN virtually eliminate the risk of cancer‐specific mortality in patients with T1a–b RCC. Poor preoperative ASA score and impaired renal function appear to represent relative contra‐indications to surgical management of T1a–b lesions.
Intestinal reconstruction of the lower urinary tract as a prerequisite for renal transplantation
Authors: Djakovic Nenad , Wagener Nina , Adams Judith , Gilfrich Christian , Haferkamp Axel , Pfitzenmaier Jesco , Toenshoff Burkhard , Schmidt Jan , Hohenfellner Markus
Published: December 2008

OBJECTIVE

To report a two‐stage protocol for children in whom bladder reconstruction was followed by kidney transplantation, as about a quarter of children requiring a kidney transplantation show significant lower urinary tract dysfunction, and consequently their bladder is unsuitable for a kidney transplant.

PATIENTS AND METHODS

Twelve children (median age 9.5 years, range 4.2–16.8) with end‐stage renal disease had a lower urinary tract reconstruction before kidney transplantation. The cause of bladder dysfunction and renal failure included posterior urethral valves in five, neuropathic bladder in two, prune‐belly syndrome in two, anal‐rectum and urethral atresia syndrome in one, primary obstructive uropathy in one and caudal regression syndrome in one. Two children were diverted with an ileal conduit; four had a bladder augmentation, and four had a bladder augmentation with additional continent cutaneous stoma. A continent urinary reservoir was constructed in one boy, and one boy had a Mitrofanoff‐only procedure. Subsequently, 11 children were transplanted.

RESULTS

The graft survival rate was 11 of 12 at 1 year and eight of 12 at 5 years. No patient lost the graft related to the reconstructed lower urinary tract. During the median (range) follow‐up of 5.4 (1.6–12.5) years all but one child had free drainage of the upper urinary tract. All 10 children who did not have an ileal conduit are continent.

CONCLUSION

Reconstruction of the lower urinary tract followed by renal transplantation is a safe and efficient approach. It has the advantage of restoring the lower urinary tract before immunosuppressive therapy, and supplies the best possible reservoir for a transplanted kidney.
ON THE PROBABILITY OF BEING MAXIMAL
Authors: Li Deyuan
Published: December 2008

Let X1, X2, … , Xn be independent and identically distributed random variables with a continuous cumulative distribution function F, which belongs to the max‐domain of attraction of the Frechet or Gumbel extreme value distribution. We define the probability of being maximal, Dn, and approximate it. Several previous papers have considered this problem, but only for special cases. The approximations to Dn are very useful for obtaining demand functions from random utility models in the qualitative response models used in social sciences.
The Importance of Temporal Distinctiveness for Forgetting Over the Short Term
Authors: Unsworth Nash , Heitz Richard P. , Parks Nathan A.
Published: December 2008

Rapidly forgetting information once attention is diverted seems to be a ubiquitous phenomenon. The cause of this rapid decline has been debated for decades; some researchers claim that memory traces decay as a function of time out of the focus of attention, whereas others claim that prior memory traces cause confusability by interfering with the current trace. Here we demonstrate that performance after a long delay can be better than performance after a short delay if the temporal confusability between the current item and previous items is reduced. These results provide strong evidence for the importance of temporal confusability, rather than decay, as the cause of forgetting over the short term.
Boundary Conditions on Unconscious Thought in Complex Decision Making
Authors: Payne John W. , Samper Adriana , Bettman James R. , Luce Mary Frances
Published: December 2008

Should individuals delegate thinking about complex choice problems to the unconscious? We tested two boundary conditions on this suggestion. First, we found that in a decision environment similar to those studied previously, self-paced conscious thought and unconscious thought had similar advantages over conscious thought constrained to a long fixed time interval in terms of identifying the option with the highest number of positive outcomes. Second, we found that self-paced conscious thought performed better than unconscious thought in a second decision environment where performance depended to a greater extent on magnitudes of the attributes. Thus, we argue that it is critical to take into account the interaction of forms of processing with task demands (choice environments) when considering how to approach complex choice problems.
The Neural Substrates of In-Group Bias
Authors: Van Bavel Jay J. , Packer Dominic J. , Cunningham William A.
Published: December 2008

Classic minimal-group studies found that people arbitrarily assigned to a novel group quickly display a range of perceptual, affective, and behavioral in-group biases. We randomly assigned participants to a mixed-race team and used functional magnetic resonance imaging to identify brain regions involved in processing novel in-group and out-group members independently of preexisting attitudes, stereotypes, or familiarity. Whereas previous research on intergroup perception found amygdala activity—typically interpreted as negativity—in response to stigmatized social groups, we found greater activity in the amygdala, fusiform gyri, orbitofrontal cortex, and dorsal striatum when participants viewed novel in-group faces than when they viewed novel out-group faces. Moreover, activity in orbitofrontal cortex mediated the in-group bias in self-reported liking for the faces. These in-group biases in neural activity were not moderated by race or by whether participants explicitly attended to team membership or race, a finding suggesting that they may occur automatically. This study helps clarify the role of neural substrates involved in perceptual and affective in-group biases.
Initial Training With Difficult Items Facilitates Information Integration, but Not Rule-Based Category Learning
Authors: Spiering Brian J. , Ashby F. Gregory
Published: December 2008

Previous research has disagreed about whether a difficult cognitive skill is best learned by beginning with easy or difficult examples. Two experiments that clarify this debate are reported. Participants in both experiments received one of three types of training on a difficult perceptual categorization task. In one condition, participants began with easy examples, then moved to examples of intermediate difficulty, and finished with the most difficult examples. In a second condition, this order was reversed, and in a third condition, participants saw examples in a random order. The results depended on the type of categories that participants were learning. When the categories could be learned via explicit reasoning (a rule-based task), the three training procedures were equally effective. However, when the categorization rule was difficult to describe verbally (an information-integration task), participants who began with the most difficult items performed much better than participants in the other two conditions.
Social Representations and Repression: Examining the First Formulations of Freud and Moscovici
Authors: BILLIG MICHAEL
Published: December 2008

The English edition of Moscovici's classic work on the social representation of psychoanalysis enables us to reflect on the historical origins of psychoanalytic ideas and of social representation theory itself. Moscovici claimed that science was both univocal and abstract and, in these respects, it differs from the social representations of commonsense. This paper explores these notions, especially in relation to Moscovici's claim that psychoanalytic theory is to be found in Freud's first formulations. It is suggested that some of the processes, which Moscovici attributes to the passage of psychoanalytic ideas to commonsense, can be found occur in the early history of psychoanalysis. This can be seen in Freud's criticisms of the way Jung used the concept of “complex”. Moreover, psychoanalytic theory could never be univocal for it incorporated the voices of patients and their representations of the world. An examination of Studies on Hysteria reveals further multivocality as Freud uses both the “action” language of ordinary life and the reified, nominalized language of science. Examples are given in relation to the first formulations of the key psychoanalytic concept of “repression”. Some comparisons are made between Freud's first formulations of “repression” and Moscovici's first formulations of “social representation”.
Jamaica bound? Marine resources and management at a crossroads in Antigua and Barbuda
Authors: CARR LIAM M , HEYMAN WILLIAM D
Published: December 2008

Antigua and Barbuda is rapidly developing a tourism industry built around a marketed perception of a healthy marine and coastal environment. Yet economic indicators suggest that Antigua and Barbuda is overexploiting its marine resources, particularly its fish and coral reef communities. Although its marine resources remain relatively healthy, Antigua and Barbuda will jeopardise the ecological basis of its economic growth and sustainability if current exploitation rates continue. We compare the current situation and economic trends of Antigua and Barbuda's tourism and commercial fishery industries to those of Jamaica and other OECS member states. Jamaica is suggested as a cautionary example of the potential socioeconomic and ecological impacts caused by resource overexploitation and mismanagement within the various economic sectors. Antigua and Barbuda is at a crossroads. The ‘Jamaica path’ leads to large‐scale resource depletion, fishery collapse, and a mass tourism industry that can operate independent of a healthy environment. Alternatively, it can pursue a path that seeks to conserve its marine resources. Antigua and Barbuda will be better able to protect its sustainability both for commercial fishing interests and its growing high‐end destination tourism industry. To this end, Antigua and Barbuda has developed a network of marine‐protected areas along the northeastern coast of Antigua, an area popular with both fishers and tourists.
Racial and Ethnic Differences in Emergency Care for Acute Exacerbation of Chronic Obstructive Pulmonary Disease
Authors: Tsai Chu‐Lin , Camargo Jr Carlos A
Published: December 2008

Objectives:  The objective was to investigate racial and ethnic differences in emergency care for patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD).

Methods:  The authors performed a prospective multicenter cohort study involving 24 emergency departments (EDs) in 15 U.S. states. Using a standard protocol, consecutive ED patients with AECOPD were interviewed, their charts reviewed, and 2‐week telephone follow‐ups were completed.

Results:  Among 330 patients, 218 (66%) were white, 84 (25%) were African American, and 28 (8%) were Hispanic. A quarter of the 24 EDs cared for 59% of all minority patients. Compared with white patients, African American and Hispanic patients were more likely to be uninsured or with Medicaid (19, 49, and 52%, respectively; p < 0.001), were less likely to have a primary care provider (93, 81, and 82%, respectively; p = 0.005), and had more frequent ED visits in the past year (medians = 1, 2, and 3, respectively; p = 0.002). In the unadjusted analyses, minority patients were less likely to receive diagnostic procedures, more likely to receive systemic corticosteroids in the ED, less likely to be admitted, and more likely to have a relapse. After adjustment for patient and ED characteristics, these many racial and ethnic differences in quality of care were nearly completely eliminated.

Conclusions:  Despite pronounced racial and ethnic differences in stable COPD, all racial and ethnic groups received comparable quality of emergency care for AECOPD and had similar short‐term outcomes.