System and climate related pythium problems in mobile chrysanthemum growing systems

One Dutch greenhouse company started to grow chrysanthemums in a mobile system. The system’s basic unit is a sub-irrigated V-shaped gully of 8.0 m long and 5 cm wide, filled with a peat-coir mix. The system is hampered by growth differences along the length profile of the gullies and Pythium related yield reductions of up to 10% during the summer period. A series of experiments aimed to mimic the problems, explain causes and to advice on improvements. A Pythium ultimum pathogen from the grower was cultured in the laboratory and disseminated in the irrigation water tanks. In part of the cultivations the plants were subjected to high temperature and low air humidity treatments aimed at creating stress and Pythium susceptibility. Various plugs fit for transporting rooted chrysanthemum cuttings were tested as well. The results show that Pythium ultimum is initially the result of a too high water content in the first 10 days of the propagation phase. This was a direct consequence of precipitation of pure water by the mist system used to keep the relative humidity high. A related factor was a too low EC o

Wortelverdikking bij komkommer : pH, potsoort en waardplanten

Wortelverdikking (WVD) bij komkommer komt een aantal jaren in Nederland voor. Uit eerder onderzoek kwam naar voren dan de vermoedelijke veroorzaker een bacterie is. Over het gedrag van de bacterie en het effect van omgevingsfactoren op het optreden van WVD was nog zeer weinig bekend. In het onderzoek zijn verschillende aspecten van het gedrag van de bacterie onderzocht en is bekeken of de kans op WVD en schade door WVD kan worden verminderd door teeltaanpassingen. Hierbij is het effect onderzocht van pH op WVD, de overlevingsduur van de bacterie in de voedingsoplossing en het effect van potsoort en watergehalte van de opkweekpot op WVD. Tevens is onderzocht of planten die niet tot de komkommerachtigen behoren aangetast kunnen worden door de bacterie, of de bacterie droge condities kan overleven en of door verlaging van de pH in het teeltsubstraat WVD-schade kan worden verminderd

Phenotype of autosomal dominant spastic paraplegia linked to chromosome 2

Summary We report the clinical features of 12 families with autosomal dominant spastic paraplegia (ADSP) linked to the SPG4 locus on chromosome 2p, the major locus for this disorder that accounts for ∼40% of the families. Among 93 gene carriers, 32 (34%) were unaware of symptoms but were clinically affected. Haplotype reconstruction showed that 90% of the asymptomatic gene carriers presented increased reflexes and/or extensor plantar responses independent of age at examination. The mean age at onset was 29 years, ranging from 1 to 63 years. Intra- as well as inter-familial variability of age at onset was important, but did not result from anticipation. Phenotype—genotype correlations and comparison with SPG3 and SPG5 families indicated that despite the variability of age at onset, SPG4 is a single genetic entity but no clinical features distinguish individual SPG4 patients from those with SPG3 or SPG5 mutation

Voorkomen uitval bij Lisianthus : onderzoek op 3 praktijkbedrijven

Eén van de problemen in de teelt van Lisianthus (Eustoma) is de uitval in de tweede helft van de teelt. Er zijn verschillen tussen de rassen: ‘Picolo’, ‘Fuji Aprico’, ‘Fuji White’, ‘Kyoto Purple’ en ‘Blue Purple’ zijn gevoelig. De uitval heeft een negatief effect op het bedrijfsrendement. Voor de oorzaak van het probleem werd aan de volgende oorzaken gedacht; 1. Het vermoeden was dat de uitval samenhangt met een toxische stof in de grond, die ontstaat bij de vertering van het restmateriaal van voorgaande Lisianthusteelten. Uit een literatuurstudie (Kreij, 2001) blijkt, dat bij andere gewassen aanwijzingen zijn voor autotoxiciteit; het gaat om luzerne, asperge, appel, perzik, druif en ander fruit. Uit de praktijk komen signalen, dat een goede organische stofvoorziening van de grond een vermindering geeft van de uitval bij Lisianthus. Waarschijnlijk moet dit dan organische stof zijn, die snel afbreekbaar is. Dat dit het geval is, zou kunnen komen door het microleven in de grond, wat beter wordt bij toevoer van organische stof. Dit microleven is in staat om de toxische stof af te breken. Ook is het denkbaar, dat de toxische stof geadsorbeerd wordt aan de organische stof. 2. Een andere veronderstelling was dat door een slechte beworteling in de bovengrond en een droge grond er vochtgebrek ontstaat. Door in de tweede helft van de teelt nagenoeg geen water te geven wordt bij de Lisianthusteelt bloemknopvorming geïnduceerd. Een te extreme droogte zou mogelijk uitval geven. 3. In uitgevallen plantmateriaal worden meermalen vaatziekten zoals Myrothecium en Fusarium geïsoleerd. Bij determinatie blijkt, bij monde van Dhr. J. Meffert van de PD het voornamelijk te gaan om F. avenaceum en F. solani . Mogelijk wordt de grond onvoldoende goed gestoomd. Stomen met onderdruk in de grond zou aanzienlijk beter resultaat opleveren. 4. Voor de vertering van het restmateriaal is extra zuurstof nodig. Mogelijk ontstaat er zuurstof tekort in de grond, waardoor de wortels afsterven, wat ook tot uitval van de planten kan leiden

The role of pain and functional impairment in the decision to recommend total joint replacement in hip and knee osteoarthritis: an international cross-sectional study of 1909 patients. Report of the OARSI-OMERACT Task Force on total joint replacement

International audienceSummary Objective To assess the pain and functional disability levels corresponding to an indication for total joint replacement (TJR) in hip and knee osteoarthritis (OA). Methods Design: International cross-sectional study in 10 countries. Patients: Consecutive outpatients with definite hip or knee OA attending an orthopaedic outpatient clinic. Gold standard measure for recommendation for TJR: Surgeon's decision that TJR is justified. Outcome measures: Pain (ICOAP: intermittent and constant osteoarthritis pain, 0-100) and functional impairment (HOOS-PS/KOOS-PS: Hip/Knee injury and Osteoarthritis Outcome Score Physical function Short-form, 0-100). Analyses: Comparison of patients with vs without surgeons' indication for TJR. Receiver Operating Characteristic (ROC) curve analyses and logistic regression were applied to determine cut points of pain and disability defining recommendation for TJR. Results In all, 1909 patients were included (1130 knee/779 hip OA). Mean age was 66.4 [standard deviation (SD) 10.9] years, 58.1% were women; 628/1130 (55.6%) knee OA and 574/779 (73.7%) hip OA patients were recommended for TJR. Although patients recommended for TJR (yes vs no) had worse symptom levels [pain, 55.5 (95% confidence interval 54.2, 56.8) vs. 44.9 (43.2, 46.6), and functional impairment, 59.8 (58.7, 60.9) vs. 50.9 (49.3, 52.4), respectively, both P < 0.0001], there was substantial overlap in symptom levels between groups, even when adjusting for radiographic joint status. Thus, it was not possible to determine cut points for pain and function defining 'requirement for TJR'. Conclusion Although symptom levels were higher in patients recommended for TJR, pain and functional disability alone did not discriminate between those who were and were not considered to need TJR by the orthopaedic surgeon

Clinical Heterogeneity of Autosomal Recessive Spastic Paraplegias: Analysis of 106 Patients in 46 Families

Background Hereditary spastic paraplegias (HSPs) are a heterogeneous group of neurodegenerative disorders characterized by progressive and predominant spasticity of the lower limbs, in which dominant, recessive, and X-linked forms have been described. While autosomal dominant HSP has been extensively studied, autosomal recessive HSP is less well known and is considered a rare condition. Objective To analyze the clinical presentation in a large group of patients with autosomal recessive HSP from Portugal and Algeria to define homogeneous groups that could serve as a guide for future molecular studies. Results Clinical features in 106 patients belonging to 46 Portuguese and Algerian families with autosomal recessive HSP are presented, as well as the results of molecular studies in 23 of these families. Five phenotypes are defined: (1) pure early-onset families, (2) pure late-onset families, (3) complex families with mental retardation, (4) complex families with mental retardation and peripheral neuropathy, and (5) complex families with cerebellar ataxia. Six additional families have specific complex presentations, each of which is unique in the present series. Pyramidal signs in the upper limbs and pes cavus are frequent findings, while pseudobulbar signs, including dysarthria, dysphagia, and brisk jaw jerks, are more frequent in the complex forms. The complex forms have a poorer prognosis, while pure forms, particularly those with early onset, are more benign. One Algerian pure early-onset kindred was linked to the locus on chromosome 8, previously reported in 4 Tunisian families. Two of the Portuguese kindreds with complex forms (one with mental retardation and the other associated with hypoplasia of the corpus callosum) showed linkage to the locus recently identified on chromosome 16. Conclusions Although autosomal recessive HSP represents a heterogeneous group of diseases, some phenotypes can be defined by analyzing a large group of patients. The fact that only one Algerian family was linked to chromosome 8 suggests that this is a rare localization even in kindreds with the same ethnic background. Linkage to chromosome 16 was found in 2 clinically diverse Portuguese kindreds, illustrating that this locus is also rare and may correspond to different phenotypes.This study was supported by Généthon, Paris, France; and 2 grants from the Portuguese Foundation for Science and Technology and the Portuguese Health Administration (projects STRDA/C/SAU/277/92 and PECS/C/SAU/219/95)

FRAX (R): Prediction of Major Osteoporotic Fractures in Women from the General Population: The OPUS Study

Purposes: The aim of this study was to analyse how well FRAXH predicts the risk of major osteoporotic and vertebral fractures over 6 years in postmenopausal women from general population. Patients and methods: The OPUS study was conducted in European women aged above 55 years, recruited in 5 centers from random population samples and followed over 6 years. The population for this study consisted of 1748 women (mean age 74.2 years) with information on incident fractures. 742 (43.1%) had a prevalent fracture; 769 (44%) and 155 (8.9%) of them received an antiosteoporotic treatment before and during the study respectively. We compared FRAXH performance with and without bone mineral density (BMD) using receiver operator characteristic (ROC) c-statistical analysis with ORs and areas under receiver operating characteristics curves (AUCs) and net reclassification improvement (NRI). Results: 85 (4.9%) patients had incident major fractures over 6 years. FRAXH with and without BMD predicted these fractures with an AUC of 0.66 and 0.62 respectively. The AUC were 0.60, 0.66, 0.69 for history of low trauma fracture alone, age and femoral neck (FN) BMD and combination of the 3 clinical risk factors, respectively. FRAXH with and without BMD predicted incident radiographic vertebral fracture (n = 65) with an AUC of 0.67 and 0.65 respectively. NRI analysis showed a significant improvement in risk assignment when BMD is added to FRAXH. Conclusions: This study shows that FRAXH with BMD and to a lesser extent also without FN BMD predict major osteoporotic and vertebral fractures in the general population