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1.
Ecol Modell ; 430: 1-16, 2020 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-35769867

RESUMEN

Meiofauna are known to have an important role on many ecological processes, although, their role in food web dynamics is often poorly understood, partially as they have been an overlooked and under sampled organism group. Here, we used quantitative food web modeling to evaluate the trophic relationship between meiofauna and their food sources and how meiofauna can mediate the carbon flow to higher trophic levels in five contrasting soft-bottom intertidal habitats (including seagrass beds, mudflats and sandflats). Carbon flow networks were constructed using the linear inverse model-Markov chain Monte Carlo technique, with increased resolution of the meiofauna compartments (i.e. biomass and feeding ecology of the different trophic groups of meiofauna) compared to most previous modeling studies. These models highlighted that the flows between the highly productive microphytobenthos and the meiofauna compartments play an important role in transferring carbon to the higher trophic levels, typically more efficiently so than macrofauna. The pathway from microphytobenthos to meiofauna represented the largest flow in all habitats and resulted in high production of meiofauna independent of habitat. All trophic groups of meiofauna, except for selective deposit feeders, had a very high dependency on microphytobenthos. Selective deposit feeders relied instead on a wider range of food sources, with varying contributions of bacteria, microphytobenthos and sediment organic matter. Ecological network analyses (e.g. cycling, throughput and ascendency) of the modeled systems highlighted the close positive relationship between the food web efficiency and the assimilation of high-quality food sources by primary consumers, e.g. meiofauna and macrofauna. Large proportions of these flows can be attributed to trophic groups of meiofauna. The sensitivity of the network properties to the representation of meiofauna in the models leads to recommending a greater attention in ecological data monitoring and integrating meiofauna into food web models.

2.
Anal Bioanal Chem ; 409(3): 821-832, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27515798

RESUMEN

Significant improvements can be realized by converting conventional batch processes into continuous ones. The main drivers include reduction of cost and waste, increased safety, and simpler scale-up and tech transfer activities. Re-designing the process layout offers the opportunity to incorporate a set of process analytical technologies (PAT) embraced in the Quality-by-Design (QbD) framework. These tools are used for process state estimation, providing enhanced understanding of the underlying variability in the process impacting quality and yield. This work describes a road map for identifying the best technology to speed-up the development of continuous processes while providing the basis for developing analytical methods for monitoring and controlling the continuous full-scale reaction. The suitability of in-line Raman, FT-infrared (FT-IR), and near-infrared (NIR) spectroscopy for real-time process monitoring was investigated in the production of 1-bromo-2-iodobenzene. The synthesis consists of three consecutive reaction steps including the formation of an unstable diazonium salt intermediate, which is critical to secure high yield and avoid formation of by-products. All spectroscopic methods were able to capture critical information related to the accumulation of the intermediate with very similar accuracy. NIR spectroscopy proved to be satisfactory in terms of performance, ease of installation, full-scale transferability, and stability to very adverse process conditions. As such, in-line NIR was selected to monitor the continuous full-scale production. The quantitative method was developed against theoretical concentration values of the intermediate since representative sampling for off-line reference analysis cannot be achieved. The rapid and reliable analytical system allowed the following: speeding up the design of the continuous process and a better understanding of the manufacturing requirements to ensure optimal yield and avoid unreacted raw materials and by-products in the continuous reactor effluent. Graphical Abstract Using PAT to accelerate the transition to continuous API manufacturing.

3.
Oecologia ; 182(2): 595-609, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27272209

RESUMEN

Pollen limitation may be an important factor in accelerated decline of sparse or fragmented populations. Little is known whether hydrophilous plants (pollen transport by water) suffer from an Allee effect due to pollen limitation or not. Hydrophilous pollination is a typical trait of marine angiosperms or seagrasses. Although seagrass flowers usually have high pollen production, floral densities are highly variable. We evaluated pollen limitation for intertidal populations of the seagrass Zostera noltei in The Netherlands and found a significant positive relation between flowering spathe density and fruit-set, which was suboptimal at <1200 flowering spathes m(-2) (corresponding to <600 reproductive shoots m(-2)). A fragmented population had ≈35 % lower fruit-set at similar reproductive density than a continuous population. 75 % of all European populations studied over a large latitudinal gradient had flowering spathe densities below that required for optimal fruit-set, particularly in Southern countries. Literature review of the reproductive output of hydrophilous pollinated plants revealed that seed- or fruit-set of marine hydrophilous plants is generally low, as compared to hydrophilous freshwater and wind-pollinated plants. We conclude that pollen limitation as found in Z. noltei may be a common Allee effect for seagrasses, potentially accelerating decline and impairing recovery even after environmental conditions have improved substantially.


Asunto(s)
Polen , Polinización , Flores , Magnoliopsida , Reproducción , Semillas
4.
Mar Environ Res ; 149: 50-66, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31153060

RESUMEN

Meiofauna can play an important role in the carbon fluxes of soft-bottom coastal habitats. Investigation of their feeding behavior and trophic position remains challenging due to their small size. In this study, we determine and compare the food sources used by nematodes and benthic copepods by using stable isotope compositions, fatty acid profiles and compound specific isotope analyses of fatty acids in the mudflats, seagrass beds and a sandflat of the Marennes-Oléron Bay, France, and the Sylt-Rømø Bight, Germany. Suspended particulate organic matter was much more 13C-depleted than other food sources and meiofauna, highlighting its poor role in the different studied habitats. The very low proportions of vascular plant fatty acid markers in meiofauna demonstrated that these consumers did not rely on this food source, either fresh or detrital, even in seagrass beds. The combined use of stable isotopes and fatty acids emphasized microphytobenthos and benthic bacteria as the major food sources of nematodes and benthic copepods. Compound specific analyses of a bacteria marker confirmed that bacteria mostly used microphytobenthos as a substrate.


Asunto(s)
Organismos Acuáticos/metabolismo , Copépodos/metabolismo , Cadena Alimentaria , Sedimentos Geológicos/análisis , Nematodos/metabolismo , Animales , Organismos Acuáticos/química , Bacterias/química , Bacterias/metabolismo , Bahías , Isótopos de Carbono/análisis , Isótopos de Carbono/metabolismo , Diatomeas/química , Diatomeas/metabolismo , Ecosistema , Ácidos Grasos/análisis , Ácidos Grasos/metabolismo , Conducta Alimentaria , Francia , Sedimentos Geológicos/química , Alemania , Microalgas/química , Microalgas/metabolismo , Isótopos de Nitrógeno/análisis , Isótopos de Nitrógeno/metabolismo , Estaciones del Año , Tracheophyta/química , Tracheophyta/metabolismo
5.
Rofo ; 157(1): 11-4, 1992 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-1637997

RESUMEN

MRI of the head was performed in 25 patients suffering from Wegener's granuloma. 23 patients showed evidence of mucosal thickening in the paranasal sinuses, the middle and inner ears and in the mastoid cells; these were characterised by low signal intensity of T1-weighted and high signal intensity of T2-weighted images. In 10 patients there were granulomas in the paranasal sinuses and in the orbits which showed low signal intensity of both T1-weighted and T2-weighted images. In 4 patients, additional images were obtained after the intravenous injection of Gd-DTPA. In 2 patients this resulted in non-homogeneous contrast accumulation in the granuloma. In 7 patients there were signal changes in the brain which were typical of infarcts. The complete extent of bone destruction in the facial skeleton was visible only by CT.


Asunto(s)
Granulomatosis con Poliangitis/diagnóstico , Cabeza/patología , Imagen por Resonancia Magnética , Adulto , Anciano , Medios de Contraste , Femenino , Gadolinio , Gadolinio DTPA , Humanos , Imagen por Resonancia Magnética/instrumentación , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Membrana Mucosa/patología , Compuestos Organometálicos , Ácido Pentético
6.
Adv Exp Med Biol ; 336: 315-7, 1993.
Artículo en Inglés | MEDLINE | ID: mdl-8296625

RESUMEN

Orbital granulomas may complicate the course of Wegener's granulomatosis (WG). Granulomas that grow and compress the optic nerve may lead to blindness. Careful magnetic resonance imaging (MRI) is recommended for early detection and follow-up of intraorbital granulomas. Sufficient systemic immunosuppressive treatment should be given as usual for Wegener's granulomatosis. In order to preserve vision orbital decompression may be necessary in rapidly progressive pseudotumor of the orbit.


Asunto(s)
Granulomatosis con Poliangitis/complicaciones , Enfermedades Orbitales/etiología , Adulto , Anciano , Anticuerpos Anticitoplasma de Neutrófilos , Autoanticuerpos/sangre , Ceguera/etiología , Ciclofosfamida/uso terapéutico , Femenino , Granulomatosis con Poliangitis/tratamiento farmacológico , Humanos , Inmunoglobulina G/sangre , Masculino , Enfermedades del Nervio Óptico/etiología , Prednisolona/uso terapéutico
7.
Adv Exp Med Biol ; 336: 319-21, 1993.
Artículo en Inglés | MEDLINE | ID: mdl-8296626

RESUMEN

MRI of the head was performed in 25 patients suffering from Wegener's granulomatosis. 23 patients showed mucosal inflammation in the nasal cavity and in the paranasal sinuses, 10 patients had granulomas in the paranasal sinuses and in the orbits, 7 patients had cerebral lesions, 3 patients had submucosal hemorrhages in the paranasal sinuses and 3 patients showed bone erosions or destructions in the facial skeleton, which was visible only by CT.


Asunto(s)
Granulomatosis con Poliangitis/patología , Cabeza , Imagen por Resonancia Magnética , Huesos/patología , Encéfalo/patología , Femenino , Humanos , Cavidad Nasal/patología , Enfermedades Orbitales/patología , Enfermedades de los Senos Paranasales/patología , Sinusitis/patología
8.
Blutalkohol ; 31(3): 178-85, 1994 May.
Artículo en Inglés | MEDLINE | ID: mdl-8049036

RESUMEN

The absorption phase of alcohol is typically accompanied by more marked behavioral effects than the elimination phase. The mechanism behind this so-called "rising tide phenomenon" has not been fully elucidated. We hypothesized that the rising tide of alcohol during the absorption phase increases the permeability of the blood-brain barrier (BBB), thus elevating the free water content with consequent edema. The resulting increase in intracranial pressure, combined with alcohol's direct toxic effects, results in a synergetic reinforcement of the symptoms of intoxication. To test this hypothesis we performed proton magnetic resonance imaging (MRI) on the human brain during the alcohol absorption and elimination phases. Our results indicate that the alcohol-induced transient opening of the BBB is a possible factor behind the rising tide phenomenon.


Asunto(s)
Consumo de Bebidas Alcohólicas/metabolismo , Encéfalo/metabolismo , Etanol/farmacocinética , Imagen por Resonancia Magnética , Adulto , Encéfalo/patología , Humanos , Masculino , Tasa de Depuración Metabólica/fisiología , Valores de Referencia
9.
Bildgebung ; 60(2): 97-100, 1993 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-8358220

RESUMEN

Two cases of asymptomatic intralobar pulmonary sequestrations are reported. Chest radiographs showed a solid intrapulmonary mass left posterior at the base. By computed tomography the exact localization and relationship of the sequesters to the surrounding tissue were demonstrated, and a bolus injection of contrast medium revealed the supplying arteries. The arteriography showed a single arterial supply in both cases and their exact course. In the late phase the pulmonary veins were visualized. Finally a suggested diagnostic workup is given.


Asunto(s)
Secuestro Broncopulmonar/diagnóstico por imagen , Adulto , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Venas Pulmonares/diagnóstico por imagen , Tomografía Computarizada por Rayos X
10.
Aktuelle Radiol ; 2(3): 159-61, 1992 May.
Artículo en Alemán | MEDLINE | ID: mdl-1610932

RESUMEN

Lymphangiomas are rare benign tumours of the lymphatic system and are mostly manifested in the ENT region. The authors describe a rare localisation of this disease originating in the left lower extremity and extending into the retroperitoneum and mediastinum in a 16-year old female patient. MR enabled the diagnosis and the exact determination of the extent. MR follow-up showed 1 1/2 years after the diagnosis that the lymphangiomas and the lymphangioma in the left thigh had reduced and that the proliferation of lymphangioma in the retroperitoneum and mediastinum had stagnated.


Asunto(s)
Pierna , Linfangioma/diagnóstico , Imagen por Resonancia Magnética , Neoplasias del Mediastino/diagnóstico , Neoplasias Retroperitoneales/diagnóstico , Adolescente , Femenino , Humanos
11.
Klin Monbl Augenheilkd ; 201(5): 309-16, 1992 Nov.
Artículo en Alemán | MEDLINE | ID: mdl-1479787

RESUMEN

BACKGROUND: Granulomas of the orbit can complicate Wegener's granulomatosis (WG). If they compress the optic nerve, blindness of one or both eyes may result. Therefore, early detection and sufficient treatment are important. MATERIAL AND METHODS: Computed tomography (CT) and magnetic resonance imaging (MRI) of the orbit and CNS were performed in patients suffering from WG and orbital granulomas (n = 6). The patients were seen interdisciplinary by internists, ENT-specialists, radiologists and ophthalmologists. RESULTS: 12 out of 121 biopsy proven WG-patients showed orbital granulomas during their disease process. Granulomas of the orbit could be best visualized by MRI. However, MRI and CT taken together were most informative. 6 patients with orbital granulomas are presented as case reports, in four of them WG lead to blindness of one eye. The course of orbital granulomas may be chronic progressive or acutely fulminant. Therapy of first choice is a high dosage, long-term immunosuppression with cyclophosphamide and prednisolone. CONCLUSIONS: The detection of orbital granulomas in WG is most successful using CT and MRI. In addition to that, the analysis of visual acuity and visual field are the most important parameters in the detection and follow-up of orbital granulomas. A high dosage, long-term immunosuppression is the treatment of first choice, but in rapidly progressive cases an early decompression of the orbit has to be discussed additionally.


Asunto(s)
Granulomatosis con Poliangitis/diagnóstico , Imagen por Resonancia Magnética , Enfermedades Orbitales/diagnóstico , Tomografía Computarizada por Rayos X , Absceso/diagnóstico , Absceso/tratamiento farmacológico , Corticoesteroides/uso terapéutico , Adulto , Anciano , Femenino , Estudios de Seguimiento , Granulomatosis con Poliangitis/tratamiento farmacológico , Humanos , Inmunosupresores/uso terapéutico , Masculino , Persona de Mediana Edad , Atrofia Óptica/diagnóstico , Atrofia Óptica/tratamiento farmacológico , Enfermedades Orbitales/tratamiento farmacológico , Agudeza Visual/efectos de los fármacos
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