From homogeneous to fractal normal and tumorous microvascular networks in the brain

We studied normal and tumorous three-dimensional (3D) microvascular networks in primate and rat brain. Tissues were prepared following a new preparation technique intended for high-resolution synchrotron tomography of microvascular networks. The resulting 3D images with a spatial resolution of less than the minimum capillary diameter permit a complete description of the entire vascular network for volumes as large as tens of cubic millimeters. The structural properties of the vascular networks were investigated by several multiscale methods such as fractal and power- spectrum analysis. These investigations gave a new coherent picture of normal and pathological complex vascular structures. They showed that normal cortical vascular networks have scale- invariant fractal properties on a small scale from 1.4 lm up to 40 to 65 lm. Above this threshold, vascular networks can be considered as homogeneous. Tumor vascular networks show similar characteristics, but the validity range of the fractal regime extend to much larger spatial dimensions. These 3D results shed new light on previous two dimensional analyses giving for the first time a direct measurement of vascular modules associated with vessel-tissue surface exchange

Mapping of quantitative-trait loci (QTL) for adult-plant resistance to Septoria tritici in five wheat populations (Triticum aestivum L.)

Septoria tritici blotch (STB), caused by Septoria tritici (teleomorph Mycosphaerella graminicola), is one of the most important diseases in wheat varieties worldwide, responsible for severe damage of the leaves causing yield losses between 30 and 40 %. Control of STB includes crop rotation, soil tillage, fungicide application, and cultivation of resistant varieties. Profit-making wheat growers are forced to apply narrow crop rotations under reduced tillage. Some fungicides including widely-used strobilurins are no longer effective due to mutations in the highly variable pathogen population of S. tritici. Therefore, resistance breeding using genetic mapping to identify quantitative-trait loci (QTL) associated with STB resistance provides a promising strategy for controlling the disease. The main goal of this study was to detect chromosomal regions for quantitative adult-plant resistance of winter wheat to STB. Besides this, we analyzed the genetic diversity of 24 European varieties after inoculation with four different isolates of S. tritici. Multienvironmental field trials inoculated with S. tritici were applied to test isolates and varieties and to phenotype mapping populations. In detail, the objectives were to (1) compare natural infection and inoculation, (2) evaluate genotypic variation of adult-plant resistance to STB in European varieties, (3) analyze genotype x environment (G x E) interaction, (4) evaluate and analyze phenotypic data including STB severity, heading date (HED), and plant height (PLH) of five mapping populations, (5) construct genetic linkage maps of these populations using AFLP, DArT, and SSR markers, (6) determine number, positions, and genetic effects of QTL for evaluated traits, and (7) reveal QTL regions for multiple-disease resistance within mapping populations using QTL meta-analysis. In all trials, inoculation with one to four preselected isolates was performed and STB severity was visually scored plotwise as percentage coverage of flag leaves with lesions bearing pycnidia. 24 winter wheat varieties were chosen with maximal differentiation in resistance to STB and evaluated across three years including nine environments. Five mapping populations, Florett/Biscay, Tuareg/Biscay, History/Rubens, Arina/Forno, and Solitär/Bussard, each comprising a cross of a resistant and a susceptible variety, with population sizes ranging from 81 to 316, were phenotyped across four to six environments. In parallel, 221 to 491 polymorphic genetic markers were assigned to linkage groups covering 1,314 to 3,305 cM of the genome. Based on these linkage maps, the number, positions, and genetic effects of QTL could be determined by composite interval mapping. Furthermore, raw data of different experiments evaluated for resistance to two other pathogens, Fusarium head blight and Stagnospora glume blotch, were used to reveal multiple-disease resistance QTL within Arina/Forno and History/Rubens populations by the software package PLABMQTL. Results of inoculated field trials coincided with not inoculated trials showing natural infection (r = 0.84 to 0.99, P < 0.01), thus inoculation method was accurate to evaluate STB severity in the field. Genotypic variation between 24 varieties ranged from 8 % (Solitär) to 63 % (Rubens) flag leaf area infected. In the analysis of variance, genotypic variance had highest impact followed by G x E interaction (P < 0.01). Therefore, environmental stability of varieties should be a major breeding goal. The varieties Solitär, History, and Florett were most stable, as revealed by a regression approach. In contrast, disease symptoms of Biscay ranged from 19 to 72 % within the three experimental years. Phenotypic data revealed significant (P < 0.01) genotypic differentiation for STB, HED, and PLH within all five mapping populations and between the parents. Entry-mean heritabilities (h²) ranged from 0.69 to 0.87 for STB, the only exception was Tuareg/Biscay (h² = 0.38). For HED (h² = 0.78 to 0.93) and PLH (h² = 0.92 to 0.98) heritabilities were high. All correlations between STB and HED (r = -0.18 to -0.33) as well as between STB and PLH (r = -0.13 to -0.45) were negative and moderate. The exception was History/Rubens which is segregating at the Rht-D1 locus showing considerably higher correlation between STB and PLH (r = -0.55, P < 0.01). The five mapping populations showed a wide and continuous distribution of mean STB severity averaged across three to six environments in field trials at adult-plant stage. In QTL analysis, one to nine, zero to nine, and four to eleven QTL were detected for STB, HED, and PLH, respectively, across five wheat populations using composite interval mapping. One to two major QTL for resistance to STB were detected consistently across environments in each population (QStb.lsa_fb-3B, QStb.lsa_fb-6D, QStb.lsa_tb-4B, QStb.lsa_tb-6B, QStb.lsa_hr-4D, QStb.lsa_hr-5B.1, QStb.lsa_af-3B, QStb.lsa_bs-7A) explaining more than 10 % of normalized adjusted phenotypic variance. Altogether, resistance QTL explained 14 to 55 % of adjusted phenotypic variance. Both parents contributed resistant alleles. Major QTL, however, were all from the resistant parent. QTL meta-analysis revealed each of four loci for multiple-disease resistance located on chromosomes 3B, 4B, 5B, and 6D in Arina/Forno, and on chromosomes 2B, 4D, 5B, and 7B in History/Rubens. The most effective meta QTL was on chromosome 4D in History/Rubens closely linked to Rht-D1. The resistance allele from History reduced disease severity by 9.8 % for STB and 6.3 % for FHB, thus explaining 47 % and 60 % of partial phenotypic variance. In general, European wheat varieties showed a wide range of genotypic variation for STB resistance useful for breeding. Although the influence of environment and G x E interaction was high, some resistant varieties which were stable across multiple environments were found (Solitär, History, Florett). Genomic regions associated with STB resistance were mapped across 13 out of 21 wheat chromosomes. Together with the continuous distribution of five segregating populations for flag leaf infection, it can be concluded that the adult-plant resistance to S. tritici was inherited quantitatively depending on several loci explaining part of phenotypic variance. QTL meta-analysis across three severe pathogens, including Fusarium head blight, Stagnospora glume blotch, and STB, within two populations revealed eight loci for multiple-disease resistance with closely linked markers applicable in resistance breeding. Combining detected major QTL as well as meta QTL in present breeding material by applying marker-assisted selection seems a promising approach to the breeding of varieties with improved resistance to Septoria tritici blotch, Fusarium head blight, and Stagnospora glume blotch.Die Septoria-Blattdürre (Septoria tritici blotch, STB) des Weizens wird durch den Erreger Septoria tritici (teleomorph Mycosphaerella graminicola) verursacht. Die gefährliche Blattkrankheit hat in den Weizenanbaugebieten der gemäßigten Breiten weltweit große Bedeutung und führt zu Ertragsverlusten zwischen 30 und 40 %. Das Befallsrisiko kann durch Fruchtfolgegestaltung, Bodenbearbeitung, Fungizidapplikation und den Anbau resistenter Sorten verringert werden. Um Kosten zu reduzieren und das Betriebseinkommen zu steigern, sind Landwirte gezwungen, Weizen in engen Fruchtfolgen mit reduzierter Bodenbearbeitung anzubauen. Die als Fungizid weit verbreiteten Strobilurine haben aufgrund von Mutationen in der sehr anpassungsfähigen Pathogenpopulation von S. tritici ihre Wirkung verloren. Die Resistenzzüchtung liefert durch die Anwendung der genetischen Kartierung zur Lokalisierung quantitativ vererbter Resistenzloci (sog. QTL) einen vielversprechenden Ansatz zur Kontrolle der Septoria-Blattdürre bei Weizen. Im Vordergrund dieser Studie stand die Lokalisation chromosomaler Regionen für die quantitativ vererbte Adultpflanzenresistenz von Weizen gegen STB. Außerdem wurde die genetische Diversität von 24 europäischen Sorten nach Inokulation mit vier verschiedenen S. tritici-Isolaten untersucht. Es wurden Feldversuche in mehreren Umwelten mit ein bis vier ausgewählten S. tritici-Isolaten inokuliert, um Isolate und Sorten zu testen und um Kartierungspopulationen zu phänotypisieren. Diese Isolate wurden so ausgewählt, dass sie nur Adultpflanzenresistenz entdecken. Die Ziele waren im Einzelnen (1) den Krankheitsbefall bei natürlicher Infektion und nach Inokulation zu vergleichen, (2) die genetische Variation für Adultpflanzenresistenz gegen STB in europäischen Sorten zu untersuchen, (3) die Genotyp x Umwelt (G x U)-Interaktion zu analysieren, (4) die phänotypischen Merkmale STB-Befall, Ährenschieben (AES) und Wuchshöhe (WUH) von fünf Kartierungspopulationen zu erheben und varianzanalytisch auszuwerten, (5) genetische Kopplungskarten dieser Populationen mit AFLP, DArT und SSR Markern zu erstellen, (6) Anzahl, Position und die genetischen Effekte der QTL für die erhobenen Merkmale zu bestimmen und (7) Genomregionen für multiple Krankheitsresistenz innerhalb der Kartierungspopulationen mit Hilfe einer QTL Meta-Analyse zu entdecken. In allen Feldversuchen wurde nach der Inokulation der prozentuale Krankheitsbefall mit STB auf dem Fahnenblatt im Mittel über die Parzelle visuell erfasst. 24 Weizensorten, die sich in der Resistenz gegen STB unterscheiden, wurden über drei Jahre in neun Umwelten angebaut. Fünf Kartierungspopulationen, Florett/Biscay, Tuareg/Biscay, History/Rubens, Arina/Forno und Solitär/Bussard, jeweils Kreuzungen aus einer resistenten und einer anfälligen Sorte mit Populationsgrößen zwischen 81 und 316 Genotypen wurden in vier bis sechs Umwelten phänotypisiert. Parallel wurden je Population 221 bis 491 polymorphe Marker den einzelnen Kopplungsgruppen zugeordnet. Die entstandenen genetischen Karten hatten eine Genomabdeckung von 1.314 bis 3.305 cM. Auf der Grundlage dieser genetischen Karten konnten die Anzahl, die Positionen und die genetischen Effekte der QTL für die erhobenen Merkmale bestimmt werden. Hierzu wurde das Verfahren der Intervallkartierung unter Einbeziehung von Kofaktoren verwendet. Darüber hinaus wurden die ursprünglichen Daten aus anderen Feldexperimenten zur Untersuchung der Resistenz gegen zwei weitere bedeutende Krankheitserreger, Ährenfusarium und Spelzenbräune, verwendet, um QTL für multiple Krankheitsresistenz innerhalb der Populationen Arina/Forno und History/Rubens zu entdecken. Die Ergebnisse der inokulierten Parzellen stimmten gut mit den Boniturwerten in natürlich infizierten Parzellen überein (r = 0,84 bis 0,99, P < 0,01). Daraus lässt sich schließen, dass die eingesetzte Inokulationsmethodik geeignet war, um den Befall mit STB im Feld auch unter ungünstigen Bedingungen zu gewährleisten und eine ähnliche Differenzierung der Weizensorten wie in der Praxis zu ermöglichen. Zwischen den 24 Weizensorten variierte die infizierte Fahnenblattfläche von 8 % (Solitär) bis 63 % (Rubens) im Mittel über neun Umwelten. Die Varianzanalyse ergab einen hoch signifikanten (P < 0,01) Effekt des Genotyps und der G x U-Interaktion. Aus diesem Grund ist die Umweltstabilität der Sorten ein wichtiges Zuchtziel. In einem Regressionsansatz zeigten die Sorten Solitär, History und Florett die höchste Umweltstabilität. Im Gegensatz dazu schwankte der Befall der Sorte Biscay zwischen 19 und 72 % innerhalb der Umwelten über drei Versuchsjahre. Die varianzanalytische Auswertung der phänotypischen Daten ergab sowohl innerhalb der fünf Kartierungspopulationen als auch zwischen deren Eltern eine hoch signifikante (P < 0,01) genotypische Differenzierung für alle drei Merkmale STB, AES und WUH. Die Heritabiltät (h²) für STB lag zwischen 0,69 und 0,87, außer bei Tuareg/Biscay (h² = 0,38). Die Heritabilitäten für AES (h² = 0,78 bis 0,93) und WUH (h² = 0,92 bis 0,98) waren in allen Populationen sehr hoch. Die Korrelationen zwischen STB und AES (r = -0,18 bis -0,33) als auch zwischen STB und WUH (r = -0,13 bis -0,45) waren negativ und signifikant (P < 0,01), aber von geringer Bedeutung. Die einzige Ausnahme war die Population History/Rubens, die am für die Wuchshöhe relevanten Rht-D1-Locus aufspaltet und deshalb eine deutlich höhere signifikant negative Korrelation zwischen STB und WUH aufwies (r = -0,55, P < 0,01). Alle fünf Kartierungspopulationen zeigten im Adultpflanzenstadium eine breite und kontinuierliche Häufigkeitsverteilung der Befallsmittelwerte aus Feldversuchen in drei bis sechs Umwelten. In der QTL-Analyse wurden in den fünf Weizenpopulationen für die drei Merkmale STB, AES und WUH ein bis neun, null bis neun und vier bis elf QTL detektiert. Für die Resistenz gegen STB wurden in jeder Population ein bis zwei Major-QTL kartiert (QStb.lsa_fb-3B, QStb.lsa_fb-6D, QStb.lsa_tb-4B, QStb.lsa_tb-6B, QStb.lsa_hr-4D, QStb.lsa_hr-5B.1, QStb.lsa_af-3B, QStb.lsa_bs-7A), die jeweils mehr als 10 % der normalisierten adjustierten phänotypischen Varianz erklärten. Insgesamt erklärten alle 26 gefundenen Resistenz QTL zusammen 14 bis 55 % der adjustierten phänotypischen Varianz in den fünf Populationen. Resistenzallele stammten vom resistenten aber auch vom anfälligen Elter, während sie bei den gefundenen Major-QTL alle vom resistenten Elter kamen. Die abschließende Meta-Analyse entdeckte acht Loci für multiple Krankheitsresistenz, vier in Arina/Forno auf den Chromosomen 3B, 4B, 5B und 6D, sowie vier in History/Rubens auf den Chromosomen 2B, 4D, 5B und 7B. Den mit Abstand größten Effekt zeigte der Meta-QTL auf Chromosom 4D in History/Rubens, der eng gekoppelt ist mit Rht-D1. Die Resistenz von History reduziert sowohl den Fahnenblattbefall mit STB um 9,8 % als auch den Ährenbefall mit Fusarium um 6,3 % und erklärt damit jeweils 47 % bzw. 60 % der partiellen phänotypischen Varianz. Die Studie hat gezeigt, dass in europäischen Weizensorten eine für die Züchtung nutzbare, breite genetische Variation für die Resistenz gegen STB vorhanden ist. Obwohl der Einfluss der Umwelt als auch die G x U-Interaktion bedeutend waren, wurden einige resistente Sorten mit hoher Umweltstabilität gefunden (Solitär, History, Florett). Auf 13 von 21 Chromosomen des Weizens wurden QTL für die Resistenz gegen STB kartiert. Die kontinuierliche Häufigkeitsverteilung des Fahnenblattbefalls in allen fünf segregierenden Populationen zusammen mit der großen Anzahl von 26 gefundenen QTL lässt darauf schließen, dass die Adultpflanzenresistenz gegen S. tritici quantitativ vererbt wird. Die hier vorgestellte QTL-Meta-Analyse innerhalb zweier Kartierungspopulationen über die drei bedeutenden Pathogene Ährenfusarium, Spelzenbräune und STB konnte acht Loci mit eng gekoppelten Markern für multiple Krankheitsresistenz detektieren. Ein vielversprechender Ansatz in der Resistenzzüchtung ist die Anwendung der markergestützen Selektion. Dadurch ist es möglich sowohl die gefundenen Major-QTL als auch die Meta-QTL im Zuchtmaterial zu kombinieren und somit neue Sorten mit verbesserter Resistenz gegenüber Septoria-Blattdürre, Ährenfusarium und Spelzenbräune zu züchten

Electrical weed control in sugar beet - A comparison of pre-emergence methods

Im Zuckerrübenanbau können schon geringe Unkrautdichten zu enormen Ertragseinbußen führen. Diese wurden in der Vergangenheit durch den Einsatz von chemischen Herbiziden effektiv begrenzt. Mit Blick auf den zunehmenden Wegfall verfügbarer chemischer Wirkstoffe, wachsender Unkrautresistenzen, einen nachhaltigeren Bodenschutz und die Einhaltung anspruchsvollerer Ernährungssicherungsstandards müssen neue Managementansätze für einen moderneren Pflanzenschutz umgesetzt werden. Aus diesem Grund wurde die elektrische Unkrautbekämpfung im Vorauflauf in der Zuckerrübe, im Mulchsaatverfahren angebaut, in chemische und mechanische Unkrautbekämpfungsstrategien integriert. Es wurde ein randomisiertes Blockfeldversuchsdesign mit dreimal replizierten Versuchsplots und acht Varianten angewendet, wobei einzelne Plots (100 m Länge) jeweils in 50 m getrennt, mit und ohne Glyphosat als Vorsaatanwendung behandelt wurden. Das Electroherb™ der Firma Zasso wurde mit 3 und 5 km&nbsp;h‑1 Fahrgeschwindigkeit und 72 kW elektrischer Nennleistung in einer 3 m Flächenbehandlung angewendet. Der Unkrautdichte nach der Vorauflauf-Applikation setzte sich hauptsächlich aus Ausfallgetreide und zweikeimblättrigen Unkrautpflanzen zusammen und betrug 5 bis 23 Pflanzen 10 m-2, während ohne Glyphosatanwendung 5 bis 97 Pflanzen 10 m-2 gezählt wurden. Der Vergleich der Wirkungsgrade zeigte, dass die Verunkrautung am besten mit der Electroherb™ Technologie kontrolliert wurde, so dass in den Parzellen ohne Glyphosatanwendung deutlich geringere Unkrautzahlen (von 5 bis 11 Pflanzen 10 m-2) vor dem Auflaufen der Zuckerrüben zurückblieben. Mechanisches Eggen auf der anderen Seite zeigte eine geringe Effizienz bei der Reduzierung von Ausfallgetreide; die durchschnittliche Unkrautdichte betrug hier 72 Pflanzen 10 m-2. Die Ergebnisse zum Zuckerrübenertrag und -qualität werden in den Datensatz integriert und erlauben so umfassende Schlussfolgerungen zur Wirtschaftlichkeit des Electroherb™ Verfahrens zu schlussfolgern. Unsere Ergebnisse zeigen, dass die Integration von elektrischen Unkrautbekämpfungsmethoden in bestehende Strategien den Einsatz von synthetisch-chemischen Herbiziden reduzieren kann und auch einen wesentlichen Beitrag zur Vermeidung von Herbizidresistenzen leisten kann.Competition between sugar beet and weeds can result in tremendous yield losses, which were confined by the use of chemical herbicides in the past. In view to address soil conservation, a reducing number of available chemical herbicides, the need to prevent weed resistances and exacting food security standards, new management approaches must be implemented into modern crop protection. In this context, electrical weed control for pre-emergence in sugar beet, cultivated in mulch sowing to prevent erosion and to improve water infiltration after heavy rainfall, was integrated in chemical and mechanical weed control strategies. A randomized complete block field trial design with three times replicated plots and eight variants was applied, whereby individual plots (100 m length in total) were separated in 50 m, with and without glyphosate as pre-sowing application. The Zasso Electroherb™ was applied with 3 and 5 km h‑1 speed and 72 kW nominal electrical power in a 3 m area application. Weed infestation after the pre-emergence weed control, mainly volunteer grain and dicotyledonous weed plants, with glyphosate averaged densities of 5 to 23 plants 10 m-2, whereas without glyphosate application 5 to 97 plants 10 m-2 were counted, respectively. Weed control efficiency indicated that the weed community was controlled best by Electroherb™, leaving in the plots without glyphosate application significantly lower weed numbers (of 5 to 11 plants 10 m-2) behind. Mechanical harrowing on the other side showed here minor efficiency in reducing the volunteer grain weed; averaging weed densities of 72 plants 10 m-2. Results on sugar beet yields and quality are pending but will be included in the data set for comprehensive conclusions. Our results indicate that the integration of electrical weed control methods into existing strategies can reduce the use of synthetic-chemical herbicides and can also make a significant contribution to the prevention of ongoing and future herbicide resistances

Robotic intra-row weed hoeing in maize and sugar beet

A prototype of robotic intra-row weed hoeing in maize and sugar beet is presented in this study. Weeds in the crop rows were identified using a bi-spectral image analysis system and shape analysis. Positions of weeds in the images were recorded. Selective weed control in the row was performed with a modified finger weeder driven by electrical motors. Speed of the finger weeder was increased at positions where only weeds were classified. The system was triggered by an encoder and controlled by a micro-controller. Roboter-gesteuerte Unkrauthacke in der Reihe von Mais und ZuckerrübenEin Prototyp einer roboter-gesteuerten Hacke zur Unkrautbekämpfung in den Reihen von Mais und Zuckerrübe wird in dieser Studie vorgestellt. Unkräuter und Kulturpflanzen wurden mit einer bi-spektralen Kamera und Formenanalyse erkannt. Die Positionen der Unkräuter im Bild wurden bestimmt. Die selektive Unkrautbekämpfung in der Reihe geschah mit einer modifizierten Fingerhacke, die über Elektromotoren angetrieben werden. Die Fingerhacke wurde beschleunigt, wenn nur Unkräuter in der Reihe klassifiziert wurden. Das System wurde mit einem Inkrementalgeber getriggert und über einen Micro-Controller gesteuert

The Psychosocial Health of Shan Children in Northwest Thailand

We administered the Strengths and Difficulties Questionnaire (SDQ) to 51 Shan refugee children from Burma who are living in northern Thailand, and collected life histories from 11 of their families. Of the sample, 63% of the children were stateless, and none were Thai citizens. About 30% of the children had normal peer relationship subscores—a number well below Thai norms after correcting for multiple comparisons (p < .001). However, their overall functioning was not different from the Thai population as a whole

A prospective open-label treatment trial of olanzapine monotherapy in children and adolescents with bipolar disorder

OBJECTIVE: The goal of this study was to assess the effectiveness and tolerability of olanzapine in the treatment of acute mania in children and adolescents. METHODS: This was an 8-week, open-label, prospective study of olanzapine monotherapy (dose range 2.5-20 mg/day) involving 23 bipolar youths (manic, mixed, or hypomanic; 5-14 years old). Weekly assessments were made using the Young Mania Rating Scale (YMRS), Clinical Global Impressions Severity Scale (CGI-S), Brief Psychiatric Rating Scale, and Children\u27s Depression Rating Scale. Adverse events were assessed through self-reports, vital sign and weight monitoring, laboratory analytes, and extrapyramidal symptom rating scales (Barnes Akathisia Scale, Simpson-Angus Scale, and Abnormal Involuntary Movement Scale). RESULTS: Twenty-two of the 23 youths (96%) completed the study. Olanzapine treatment was associated with significant improvement in mean YMRS score (-19.0 +/- 9.2, p \u3c 0.001). Using predefined criteria for improvement of \u3e or = 30% decline in the YMRS and a CGI-S Mania score of \u3c or = 3 at endpoint, the overall response rate was 61%. Overall, olanzapine was well tolerated, and extrapyramidal symptom measures were not significantly different from baseline. Body weight increased significantly over the study (5.0 +/- 2.3 kg, p \u3c 0.001). CONCLUSIONS: Open-label olanzapine treatment was efficacious and well tolerated in the treatment of acute mania in youths with bipolar disorder. Future placebo-controlled, double-blind studies are warranted

Integrating freshwater biodiversity data sources: key challenges and opportunities

1. In order to better quantify spatial and temporal patterns in freshwater biodiversity, and potential underlying drivers of change, we must utilise the increasingly broad range of data available on freshwater ecosystems. Statistical advances in the field of integrated modelling provide new opportunities to further our understanding through the combined and simultaneous analysis of these diverse datasets. 2. We briefly introduce integrated modelling in the context of freshwater biodiversity and outline the key steps involved in its implementation, from data collection to analysis. We highlight both opportunities and challenges for the application of integrated approaches. 3. To illustrate the potential for integrated models to improve our understanding of freshwater biodiversity compared to standard approaches, we combine two datasets collected using different methods to model the distribution of Agabus water beetles in England. The integrated model had greater power to detect covariate effects on Agabus distribution, and reduced parameter uncertainty compared with analysis using only a single dataset. 4. We show that integrated methods have the potential to increase our understanding of freshwater systems and enable us to make full use of the diversity of freshwater data available

Substance abuse and psychiatric co-morbidity as predictors of premature mortality in Swedish drug abusers a prospective longitudinal study 1970 - 2006

<p>Abstract</p> <p>Background</p> <p>Few longitudinal cohort studies have focused on the impact of substances abused and psychiatric disorders on premature mortality. The aim of the present study was to identify predictors of increased risk of drug related death and non drug related death in substance abusers of opiates, stimulants, cannabis, sedatives/hypnotics, hallucinogens and alcohol over several decades.</p> <p>Methods</p> <p>Follow-up study of a consecutive cohort of 561 substance abusers, admitted to a detoxification unit January 1970 to February 1978 in southern Sweden, and followed up in 2006. Demographic and clinical data, substance diagnoses and three groups of psychiatric diagnoses were identified at first admission. Causes of death were coded according to ICD-10 and classified as drug related deaths or non drug related deaths. To identify the incidence of some probable risk factors of drug related premature death, the data were subjected to a competing risks Cox regression analysis.</p> <p>Results</p> <p>Of 561 patients in the cohort, 11 individuals had either emigrated or could not be located, and 204/561 patients (36.4%) were deceased by 2006. The cumulative risk of drug related death increased more in the first 15 years and leveled out later on when non drug related causes of death had a similar incidence. In the final model, male gender, regular use of opiates or barbiturates at first admission, and neurosis were associated with an increased risk of drug related premature death, while cannabis use and psychosis were associated with a decreased risk. Neurosis, mainly depression and/or anxiety disorders, predicted drug related premature death while chronic psychosis and personality disorders did not. Chronic alcohol addiction was associated with increased risk of non drug related death.</p> <p>Conclusions</p> <p>The cohort of drug abusers had an increased risk of premature death to the age of 69. Drug related premature death was predicted by male gender, the use of opiates or barbiturates and depression and anxiety disorders at first admission. The predicted cumulative incidence of drug related death was significantly higher in opiate and barbiturate abusers over the observed period of 37 years, while stimulant abuse did not have any impact. Alcohol contributed to non drug related death.</p

Biomechanical spinal growth modulation and progressive adolescent scoliosis – a test of the 'vicious cycle' pathogenetic hypothesis: Summary of an electronic focus group debate of the IBSE

There is no generally accepted scientific theory for the causes of adolescent idiopathic scoliosis (AIS). As part of its mission to widen understanding of scoliosis etiology, the International Federated Body on Scoliosis Etiology (IBSE) introduced the electronic focus group (EFG) as a means of increasing debate on knowledge of important topics. This has been designated as an on-line Delphi discussion. The text for this debate was written by Dr Ian A Stokes. It evaluates the hypothesis that in progressive scoliosis vertebral body wedging during adolescent growth results from asymmetric muscular loading in a "vicious cycle" (vicious cycle hypothesis of pathogenesis) by affecting vertebral body growth plates (endplate physes). A frontal plane mathematical simulation tested whether the calculated loading asymmetry created by muscles in a scoliotic spine could explain the observed rate of scoliosis increase by measuring the vertebral growth modulation by altered compression. The model deals only with vertebral (not disc) wedging. It assumes that a pre-existing scoliosis curve initiates the mechanically-modulated alteration of vertebral body growth that in turn causes worsening of the scoliosis, while everything else is anatomically and physiologically 'normal' The results provide quantitative data consistent with the vicious cycle hypothesis. Dr Stokes' biomechanical research engenders controversy. A new speculative concept is proposed of vertebral symphyseal dysplasia with implications for Dr Stokes' research and the etiology of AIS. What is not controversial is the need to test this hypothesis using additional factors in his current model and in three-dimensional quantitative models that incorporate intervertebral discs and simulate thoracic as well as lumbar scoliosis. The growth modulation process in the vertebral body can be viewed as one type of the biologic phenomenon of mechanotransduction. In certain connective tissues this involves the effects of mechanical strain on chondrocytic metabolism a possible target for novel therapeutic intervention

A 3D-investigation shows that angiogenesis in primate cerebral cortex mainly occurs at capillary level

International audienceThis paper describes the use of a new 3D high-resolution imaging technique dedicated to functional vessels for a systematic quantitative study of angiogenesis in the primate cortex. We present a new method which permits, using synchrotron X-ray micro-tomography imaging, the identification of micro-vascular components as well as their automatic numerical digitalization and extraction from very large 3D image analysis and post-treatments. This method is used to analyze various levels of micro-vascular organization and their postnatal modifications. Comparing newborn- and adult marmosets, we found an increase in vascular volume (270%), exchange surface (260%) and vessel length (290%) associated to a decrease in distances between vessel and tissue (32%). The increase in relative vascular volumes between the two ages, examined through the whole cortical depth, has been found to be mainly sustained by events occurring at the capillary level, and only marginally at the perforating vessel level. This work shows that the postnatal cortical maturation classically described in terms of synaptogenesis, gliogenesis and connectivity plasticity is accompanied by an intensive remodeling of micro-vascular patterns