Larval development and dispersal at deep-sea hydrothermal vents     

Lutz RA  Jablonski D  Turner RD 《Science (New York, N.Y.)》1984,226(4681):1451-1454

Deep-sea hydrothermal vent communities exhibit an array of reproductive strategies. Although a few vent species undergo planktotrophic, high-dispersal modes of development, most exhibit relatively low dispersal, but probably free-swimming nonplanktotrophic development. This predominance of nonplanktotrophy may be largely a reflection of phylogenetic constraints on the vent colonizing taxa; intervent dispersal among these forms may be facilitated by reduced developmental rates in the cold abyssal waters away from the vents. It is proposed that for those vent species with nonplanktotrophic development, larval dispersal is a stepwise process with oceanic ridge axes serving as discrete dispersal corridors.  相似文献   

Structure of Galphaq-p63RhoGEF-RhoA complex reveals a pathway for the activation of RhoA by GPCRs     

Lutz S  Shankaranarayanan A  Coco C  Ridilla M  Nance MR  Vettel C  Baltus D  Evelyn CR  Neubig RR  Wieland T  Tesmer JJ 《Science (New York, N.Y.)》2007,318(5858):1923-1927

The guanine nucleotide exchange factor p63RhoGEF is an effector of the heterotrimeric guanine nucleotide-binding protein (G protein) Galphaq and thereby links Galphaq-coupled receptors (GPCRs) to the activation of the small-molecular-weight G protein RhoA. We determined the crystal structure of the Galphaq-p63RhoGEF-RhoA complex, detailing the interactions of Galphaq with the Dbl and pleckstrin homology (DH and PH) domains of p63RhoGEF. These interactions involve the effector-binding site and the C-terminal region of Galphaq and appear to relieve autoinhibition of the catalytic DH domain by the PH domain. Trio, Duet, and p63RhoGEF are shown to constitute a family of Galphaq effectors that appear to activate RhoA both in vitro and in intact cells. We propose that this structure represents the crux of an ancient signal transduction pathway that is expected to be important in an array of physiological processes.  相似文献   

Comment on "Global convergence in the temperature sensitivity of respiration at ecosystem level"     

Graf A  Weihermüller L  Huisman JA  Herbst M  Vereecken H 《Science (New York, N.Y.)》2011,331(6022):1265; author reply 1265

Mahecha et al. (Reports, 13 August 2010, p. 838) estimated the temperature sensitivity of ecosystem respiration (Q(10)) and showed that temperature sensitivity and its site-to-site variability are lower than previously reported. We demonstrate that their Q(10) value of 1.4 is an underestimate if interpreted as the averaged sensitivities of all ecosystem components, because fast temperature fluctuations penetrate poorly into the soil.  相似文献   

Mechanische Fruchtbehangsregulierung bei Apfel verbessert Fruchtgröße,Fruchtfestigkeit, Fruchtausfärbung und die Source: Sink – Verhältnisse mit mehr Einzelfruchtständen (Singlets) bei ‘Gala’     

Claudia Seehuber  Lutz Damerow  Achim Kunz  Michael M. Blanke 《Erwerbs-Obstbau》2014,56(2):49-58

The objective of the MSc project was to improve fruit quality, i.e. fruit firmness, colour and size, by mechanical blossom thinning. Ten-year-old slender spindle apple cv. ‘Gala, Mondial’ trees at Campus Klein-Altendorf near Bonn, Germany with an intense flowering of 7–8 on the 0–9 scale were blossom-thinned on 21 April 2009; unthinned trees served as control. Rotor speeds were 360 rpm or 420 rpm at 5 or 7.5 km/h tractor speed using the new mechanical thinning device developed at the University of Bonn in 2004–2006. Therein, a vertical mast supports three horizontal rotors, whose vertically rotating tines remove excessive flowers; the device was mounted on the front three point hitch of the tractor with the following results:

1. Mechanical thinning reduced the number of apple fruit from 18 per branch section in the un-thinned control, 12–13 in the medium to 8 fruit in the strongest thinning (420 rpm, 5 km/h).
2. Similarly, the number of singlets (one fruitlet/flower cluster) nearly doubled from ca. 2 per branch in the control to 3–4 after mechanical thinning, as intended.
3. The natural June drop after mechanical thinning resembled that in the un-thinned control.
4. Mechanical thinning increased fruit mass by 20 g—48 g relative to the un-thinned control.
5. Mechanical thinning with 420 rpm increased the portion of premium fruit >?70 mm (class I) by 43?% (7.5 km/h) and 63?% (5 km/h); combined mechanical and hand-thinning yielded the largest portion of fruit >?70 mm (70?%), but with a dramatic loss in yield (55?%).
6. Mechanical and manual thinning improved the portion of well coloured fruit (75–100?% coloured) (78–98?%) when compared to the un-thinned control fruits with 55?%, probably due to selective removal of shaded fruits from the inner tree canopy.
7. Overall, mechanical thinning alone gave better results than hand thinning alone or its combination with hand-thinning in cv. ‘Gala’; mechanical thinning waived the need for hand thinning in this experiment.
8. Mechanical thinning improved fruit firmness from 9.4 kg/cm² in the un-thinned control to 10.4 kg/cm².
9. Neither vegetative growth nor subsequent fruit drop were stimulated by this type of mechanical thinning.
10. The risk of both alternate bearing and over-sized fruit was waived due to the variety employed.
11. An economic evaluation showed a net profit of € 220/ha in the weak (420 rpm—7.5 km/h) aνô € 1,844/ha in the intermediate (360 rpm—5 km/h), but a net loss of € 1,120/ha (420 rpm—5 km/h) for the strongest thinning treatment, assuming a cost of € 120/ha for the mechanical treatment and a saving of € 200 for reduced hand thinning.

Overall, the positive results of a better fruit quality (size, colour and firmness) offer the potential of mechanical blossom thinning in cv. ‘Gala’, which is difficult to blossom-thin chemically.  相似文献   

Predation on native fish eggs by invasive round goby revealed by species‐specific gut content DNA analyses     

Elisabeth Lutz  Philipp Emanuel Hirsch  Karen Bussmann  Joschka Wiegleb  Hans‐Peter Jermann  Roxane Muller  Patricia Burkhardt‐Holm  Irene Adrian‐Kalchhauser 《水产资源保护:海洋与淡水生态系统》2020,30(8):1566-1577

1. Conservation of riverine fish often aims to improve access to spawning grounds and restore longitudinal connectivity by removing migration barriers, and involves substantial investments. However, these investments also enable non‐native predators to invade upstream into spawning areas and potentially adversely affect the recruitment of threatened freshwater fish through egg or fry predation.
2. Detecting egg predation is often challenging. Visual inspections of fish gut contents may underestimate predation of soft materials such as eggs and fry, which limits the discovery of predators preying upon these life‐stages. DNA‐based detection assays may offer a more sensitive tool to assess predation of soft materials.
3. A conservation issue was confirmed by developing and applying a species‐specific DNA‐based detection assay: invasive round goby (Neogobius melanostomus) prey on the eggs or fry of the threatened common nase (Chondrostoma nasus) in Switzerland.
4. DNA‐based detection assays were also developed for five other valuable native fish species, including endangered salmonid and cyprinid river spawners. The applicability of the assays was confirmed in a series of laboratory and field feeding experiments involving eggs and fish tissue. In addition, this work provides a guiding framework for conservation managers regarding the use and applicability of different DNA‐based detection approaches for gut content analysis.
5. The results of this study could inform local conservation measures – such as temporary reductions in the density of round goby at spawning sites prior to spawning – and demonstrate how targeted application of species‐specific molecular markers may advance freshwater fish management.

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Untersuchungen zur entwicklung von stoffgehalten im aufwuchs von niedermoorstandweiden in abhängigkeit vom vegetationsverlauf: Investigations about development of stuff contents in growth of lowland moor large units pasture in dependence from vegetation progress     

Lutz Hasselmann  Andreas Fischer  Gisbert Schalitz 《Archives of Agronomy and Soil Science》2013,59(6):613-621

Der geringe Bestand an Rindern in den neuen Bundesländern lässt auch den Einsatz von Schafen zur Offenhaltung des Niedermoorgrünlandes erforderlich werden. Die hohe Selektivität bei der Futteraufnahme macht Maßnahmen des Weidemanagements erforderlich, die über die reine Standweide hinausgehen. Der Verlauf der TS-Gehalte im Aufwuchs zeigt ein deutliches Maximum im Juni. Durchwuchs junger Triebe im Sommer lässt die Gehalte im Mittel zwar absinken, der Bestand bleibt aber sehr unausgeglichen. Bei Einschaltung einer Mähnutzung werden wichtige Parameter im Sinne von Futterqualität und Verzehrleistung positiv beeinflusst (TS-Gehalt, Rohfaser, Rohprotein). Die späte Mahd ist kaum wirkungsvoll und kann auf biologisch aktiven Weideflächen durch Verteilung von Erdaufhäufungen zur Verschmutzung des Futters beitragen.  相似文献   

Short-term effects of a nun moth suppression programme (Lymantria monacha), (Lepidoptera: Lymantriidae) on epigeic non-target arthropods     

Manfred Wanner  Cornelia Wiesener  Lutz Otto  Willi E. R. Xylander 《Journal of pest science》2005,78(1):7-11

The short-term responses of non-target soil arthropods to insecticides (Nomolt: Teflubenzuron, Karate: lambda-Cyhalothrin) applied against the nun moth (Lymantria monacha L.) were investigated in 2003. This phytophagous pest infested 30–40-year-old monocultures of Scots pine (Pinus sylvestris L.) located at an active military training area in northeast Saxony (Germany). According to the non-target epigeic arthropods, extinction of a higher systematic taxon (family, order) was not observed. Activity densities of soil macroarthropods were lower on plots treated with Karate, while those of necrophagous ground beetles increased considerably. Nomolt revealed no distinct impact on soil invertebrate density. Statistical analysis did not prove any consistent insecticidal effects on non-target arthropods. Adjacent open-heathland arthropods were not affected by a possible drift of the agents.  相似文献   

Environmental persistence of equid herpesvirus type-1     

Nadia T. Saklou  Brandy A. Burgess  Laura V. Ashton  Paul S. Morley  Lutz S. Goehring 《Equine veterinary journal》2021,53(2):349-355

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Does an ARYL HYDROCARBON RECEPTOR (AHR)-like molecule exist in earthworms? Some implications for immunity.: The 7th international symposium on earthworm ecology · Cardiff · Wales · 2002     

Lutz Wiesner  Mark E. Hahn  Sibel I. Karchner  Edwin L. Cooper  Ellen Kauschke   《Pedobiologia》2003,47(5-6):646-650

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Midwest (U.S.A.) reservoir water quality modification I. Particulate parameters     

Victor I. Okereke  E. Robert Baumann  T. Al Austin  Donna Schulze Lutz 《Water, air, and soil pollution》1988,37(3-4):309-324

Both qualitative and quantitative approaches were used to evaluate the impact of a flood control, low flow augmentation reservoir on seven water quality parameters: Suspended solids and total phosphate (particulate parameters); BOD, COD, and ammonia (O₂-demanding parameters); and orthophosphate and nitrite plus nitrate N (soluble nutrients). Fourteen years of weekly sampling data above, in, and downstream of the reservoir both before and after the reservoir became operational were analyzed. This paper considers the effects of the reservoir on the particulate parameters. There was a dramatic decrease in both suspended solids and total phosphate concentrations in the reservoir discharges, particularly during periods of high river flows and high reservoir inflow parameter concentrations. At all sampling stations, the annual parameter loading rates (kg ha^?1 yr^?1) correlated linearly with annual runoff (cm yr^?1). The suspended solids removal efficiency of the reservoir was dependent on annual runoff and averaged about 90%. Non-point source contributions of suspended solids were well over 99% when annual runoff exceeded 6.57 cm y^?1 and over 95% even when annual runoff was as low as 1.63 cm yr^?1  相似文献