Effect of (Changes in) Air Humidity on Transpiration and (Adaptation of) Stomatal Closure of Tradescantia Leaves during Water Stress

This paper summarises our recent research on the physiological effects of prolonged high RH during growth on stomatal function and we discuss possibilities that arise from this work for reducing postharvest quality problems in cut flowers. Chlorophyll fluorescence imaging was used to measure stomatal closure in response to desiccation of Tradescantia virginiana leaves grown under high (90%) and moderate (55%) relative humidities, or transferred between these humidities. Stomata of plants transferred from moderate RH conditions to high RH showed the same diminished closure in response to desiccation, as did stomata that developed at high RH. This response was found both when the leaves were either fully expanded or still actively expanding during the moderate RH pre-treatment. However, when leaves were grown in high RH prior to a moderate RH treatment, the reduced stomatal closure response to desiccation was only reversed in leaves (regions) which were still actively expanding during moderate RH treatment. This indicates that with respect to stomatal responses to desiccation, high RH leaf regions have only a limited capacity to adapt after transfer to moderate RH conditions. It is suggested that the diminished stomatal closure in high RH-grown plants is the result of changes in the signalling pathway for ABA-related closure induced by a prolonged period (several days) at a low ABA level. A short increase of VPD (by decreasing RH or increasing temperature) once every 2 or 3 days is probably sufficient to overcome vase life problems of cut flowers grown at high RH. Testing the acclimation ability of stomata to desiccation by transferring high RH grown plants to low VPD for just a few days would be a simply and effective screening procedure for genotypes with more adaptable stomat

Assessment of Functions and Functional Activities of the Upper Extremity

The author was born in Rotterdam on the 21 of July 1963 and spent her childhood in Breda and Dordrecht. From 1975 to 1981 she attended Het Christelijk Lyceum (VWO ) in Dordrecht. In 1981 she started medical studies at the Erasmus University Rotterdam and obtained her medical degree in 1988. After this she worked as a resident in the departments of Surgery, Neurology and Rehabilitation Medicine for children. Three years later, in 1992, she started her residency in the department of Rehabilitation Medicine at the University Hospital Rotterdam Dijkzigt; head of the department and trainer Prof.dr. H.J. Stam. The residency consisted of 3 years rehabilitation in the university hospital and 1 year in the rehabilitation centre de Hoogstraat in Utrecht; trainer drs. W. van Haselen. From 1996 onwards, she has been a member of staff of the department of Rehabilitation Medicine at the Erasmus Medical Centre Rotterdam and has also worked, for several years, in the children's hospital Sophia, part of the Erasmus MC. Since 1999 she has been a member of the Concilium of the VRA (Vereniging voor revalidatieartsen) and since 2005 she has served as president of the Concilium. Jetty van Meeteren is married to Paul de Graaff and they have two daughters Anouk (1999) and Kyra (2003).This thesis describes different methods used to measure of functions and functional activities of the upper extremity. In rehabilitation medicine, treatment aims to improve functions, to diminish limitations in functional activities, and to achieve an optimal level of social participation. The International Classification of Functioning, Disability and Health (ICF) published in 2001 by the World Health Organization (WHO) describes the terms functions, functional activities and participation. This thesis is divided into two parts; the first part presents studies investigating measurement of the function of the shoulder and the relation with functional activities. The second part consists of studies that determine relationships between measurements of functions, functional activities of the upper extremity, and participation in young adults with cerebral palsy (CP)

De ongekende samenleving: schattingen en inzichten over irreguliere migranten en economische schaduwactiviteiten

Inleiding en probleemstelling: Overheden in landen met een hoge economische ontwikkeling beschikken doorgaans over een uitgebreid systeem om hun economie en bevolking te monitoren. Door de uitgebreidheid en de effectiviteit van deze systemen wordt er meestal van uitgegaan dat de gegevens van overheden een adequaat beeld schetsen van de werksituatie, het economische en het sociale leven ‘zoals ze zijn’. Niets is minder waar. De beschikbare informatie lijdt structureel onder het euvel dat ze voorbijgaat aan een samenleving die weliswaar reëel bestaat, maar die grotendeels verborgen blijft voor het oog van officiële waarneming en registratie. Deze ongekende samenleving geeft haar geheimen slechts mondjesmaat prijs. Tussen de gedocumenteerde werkelijkheid en het ware sociaaleconomische en werkzame leven van de inwoners van Vlaanderen gaapt een kloof. Over de oorzaken, de grootte en de veranderingen van deze kloof kan gedebatteerd worden ‑ en dat wordt daadwerkelijk gedaan – maar dat ze bestaat en significant is, wordt zelfs door oppervlakkige waarneming bevestigd. Waar hebben we het dan over, wanneer we spreken over een kloof tussen het werkelijke land en datgene dat gedocumenteerd is? Een drietal illustraties zal duidelijk maken waar het probleem zich situeert. ..

Effect of pharmacologically induced smooth muscle activation on permeability in murine colitis.

BACKGROUND: Both intestinal permeability and contractility are altered in inflammatory bowel disease. Little is known about their mutual relation. Therefore, an in vitro organ bath technique was developed to investigate the simultaneous effects of inflammation on permeability and smooth muscle contractility in different segments of the colon. METHODS AND MATERIALS: BALB/c mice were exposed to a 10% dextran sulphate sodium drinking water solution for 7 days to induce a mild colitis, while control mice received normal tap water. Intestinal segments were placed in an oxygenated organ bath containing Krebs buffer. Permeability was measured by the transport of the marker molecules 3H-mannitol and 14C-polyethyleneglycol 4000. Contractility was measured through a pressure sensor. Smooth muscle relaxation was obtained by salbutamol and l-phenylephrine, whereas contraction was achieved by carbachol and 1-(3-chlorophenyl)-biguanide. RESULTS: The intensity of mucosal inflammation increased throughout the colon. Also, regional differences were observed in intestinal permeability. In both normal and inflamed distal colon segments, permeability was diminished compared with proximal colon segments and the non-inflamed ileum. Permeability in inflamed distal colon segments was significantly decreased compared with normal distal segments. Pharmacologically induced relaxation of smooth muscles did not affect this diminished permeability, although an increased motility positively affected permeability in inflamed and non-inflamed distal colon. CONCLUSIONS: Inflammation and permeability is inversely related. The use of pro-kinetics could counteract this disturbed permeability and, in turn, could regulate the disturbed production of inflammatory mediators

Quantification of Emboli by Visualization of Air Filled Xylem Vessels

Between harvest and vase life the cut surface of most cut flowers is exposed to air for a longer or shorter period. It was hypothesized that under normal harvest and transport conditions air only enters the cut open vessels and does not move to non-cut vessels. The vessel length distribution of chrysanthemum stems was analyzed with the latex particle method and compared to the distribution of air embolisms in 5øw/w) desiccated stems, visualized using cryo-scanning electron microscopy. It was concluded that by moderate desiccation all cut open vessels are completely air-filled and that intact vessels are not embolized

The use of imaging of the efficiency of photosystem II electron transport to visualise the effect of dry storage on the photosynthesis and stomatal closure of cut rose stems

Following their harvest, cut roses are generally stored dry prior to and during transport and only rewetted once they near the end of the chain. This treatment results in overall dehydration of the rose shoots and to the development of emboli within the xylem of the stems. A major consequence of this dehydration event will be stomatal closure as a result of the water stress that develops in the leaves. In addition to reducing water loss from the leaves, stomatal closure will also have major effects on leaf photosynthesis. Quantitative chlorophyll fluorescence imaging of leaves (or any other photosynthetic tissue) permits the visualisation of how efficiently light is being used to drive photosynthetic electron transport. Stomatal closure affects photosynthesis and thus photosynthetic electron transport. So, chlorophyll fluorescence imaging can be used to visualise the responses of leaves to the water stress imposed by cutting and the relief of water stress by rewetting. Results show that the degree of recovery of stomatal opening is generally only partial and that in addition to a persistent limitation of stomatal opening, there is an effect on photosynthetic electron transport due to processes acting at the level of the mesophyll. The results obtained illustrate the usefulness of chlorophyll fluorescence imaging to rapidly and effectively visualise and measure the effect of water stress on cut flowers and to quantify their recovery from this stres

Somatostatin does not attenuate intestinal injury in dextran sodium sulphate-induced subacute colitis.

FRom several in vitro and in vivo studies involvement of somatostatin (SMS) in intestinal inflammation emerge. Acute colitis induced in rats is attenuated by the long-acting SMS analogue octreotide. We studied the potential beneficial effect of SMS on non-acute experimental colitis. BALB/c mice received either saline, SMS-14 (36 or 120 microg daily) or octreotide (3 microg daily) subcutaneously delivered by implant osmotic pumps. A non-acute colitis was induced by administration of dextran sodium sulphate (DSS) 10% in drinking water during 7 days. DSS evoked a mild, superficial pancolitis, most characterized by mucosal ulceration and submucosal influx of neutrophils. Neither SMS-14 nor octreotide reduced mucosal inflammatory score or macroscopical disease activity, although reduction of intestinal levels of interleukin-1beta (IL-1beta), IL-6 and IL-10 during DSS was augmented both by SMS and octreotide. A slight increase of neutrophil influx was seen during SMS administration in animals not exposed to DSS. In conclusion, SMS or its long-acting analogue did not reduce intestinal inflammation in non-acute DSS-induced colitis. According to the cytokine profile observed, SMS-14 and octreotide further diminished the reduction of intestinal macrophage and Th2 lymphocyte activity

Fatigue Profiles in Patients with Multiple Sclerosis are Based on Severity of Fatigue and not on Dimensions of Fatigue

Fatigue related to Multiple Sclerosis (MS) is considered a multidimensional symptom, manifesting in several dimensions such as physical, cognitive, and psychosocial fatigue. This study investigated in 264 patients with severe primary MS-related fatigue (median MS duration 6.8 years, mean age 48.1 years, 75% women) whether subgroups can be distinguished based on these dimensions. Subsequently, we tested whether MS-related