Search results for "Esox"
showing 10 items of 33 documents
Contrasting structural complexity differentiate hunting strategy in an ambush apex predator.
2021
AbstractStructural complexity is known to influence prey behaviour, mortality and population structure, but the effects on predators have received less attention. We tested whether contrasting structural complexity in two newly colonised lakes (low structural complexity lake—LSC; high structural complexity—HSC) was associated with contrasting behaviour in an aquatic apex predator, Northern pike (Esox lucius; hereafter pike) present in the lakes. Behaviour of pike was studied with whole-lake acoustic telemetry tracking, supplemented by stable isotope analysis of pike prey utilization and survey fishing data on the prey fish community. Pike displayed increased activity, space use, individual …
Zur Regiochemie von [4 + 2]-Cycloadditionen mit Methylpyrano[3,4-b]indol-3-onen und unsymmetrischen Dienophilen
1989
Die methylierten Pyrano[3,4-b]indol-3-one 1a, 1b reagieren mit acyclischen, unsymmetrischen CC-Dienophilen nach einer Diels-Alder-Reaktion/CO2-Extrusion zu selektiv funktionalisierten Carbazolen 2. In Abhangigkeit von der Struktur der Reaktionspartner wird keine oder geringe bis hohe Regioselektivitat festgestellt. Diethylmesoxalat reagiert mit 1a, 1b regioselektiv zu neuen 2,3-difunktionalisierten Indolen 4a, 4b, die aus einer regiokontrollierten [4 + 2]-Cycloaddition und Cycloreversion resultieren, wobei Pyrano[3,4-b]indoldicarbonsaure-diethylester 3a, 3b als Intermediate auftreten durften. Regiochemistry of [4 + 2] Cycloadditions with Methylpyrano[3,4–b]indol-3-ones and Unsymmetric Dieno…
Zur Reaktion vonE/Z-N-Benzolsulfonyl-3(2-methoxyvinyl)-indol mit Carbo- und Heterodienophilen: NeueDiels-Alder-Addukte aus der Indol- bzw. Carbazol-R…
1987
E/Z-Benzenesulfonyl-3(2-methoxyvinyl)-indole1 reacts viaDiels-Alder type mechanism with dimethyl acetylendicarboxylate, N-phenyltriazolindione and diethyl mesoxalate to give new cycloadducts2–5 with [b]annellated indole structures.
Fluence Rate or Cumulative Dose? Vulnerability of Larval Northern Pike (Esox lucius) to Ultraviolet Radiation
2007
Newly hatched larvae of northern pike were exposed in the laboratory to four fluence rates of ultraviolet radiation (UVR; 290-400 nm) over three different time periods, resulting in total doses ranging from 3.0 +/- 0.2 to 63.0 +/- 4.4 kJ.m(-2). Mortality and behavior of the larvae were followed for 8-12 days, and growth measured at the end of the experiment. Also, the principle of reciprocity-that the UVR-induced mortality depends on the cumulative dose, independent of fluence rate-was tested. Fluence rates higher than 1480 +/- 150 mW.m(-2) caused mortality and growth retardation. The highest fluence rate (3040 +/- 210 mW.m(-2)) caused 100% mortality in 5 days. All fluence rates caused beha…
[Cu3(Hmesox)3]3−: a Precursor for the Rational Design of Chiral Molecule-Based Magnets (H4mesox = 2-dihydroxymalonic acid)
2010
Two new compounds K(3)[Cu(3)(Hmesox)(3)(H(2)O)] x 4 H(2)O (1) and {(PPh(4))(2)[CoCu(3)(Hmesox)(3)Cl]} (2) [H(4)mesox = mesoxalic acid (2-dihydroxymalonic acid) and PPh(4)(+) = tetraphenylphosphonium cation] have been prepared and magneto-structurally characterized. Compound 1 contains the [Cu(3)(Hmesox)(3)](3-) entity which can be considered as a new precursor for molecular magnetism. In 1 the triangular arrangement of three copper(II) ions bridged by alkoxo groups are further connected to a symmetry-related tricopper(II) unit through a double oxo(carboxylate) bridge. The resulting hexacopper(II) entities are joined further through anti-syn carboxylate groups into an anionic three-dimension…
Role of Kras Status in Patients with Metastatic Colorectal Cancer Receiving First-Line Chemotherapy plus Bevacizumab: A TTD Group Cooperative Study
2012
Background: In the MACRO study, patients with metastatic colorectal cancer (mCRC) were randomised to first-line treatment with 6 cycles of capecitabine and oxaliplatin (XELOX) plus bevacizumab followed by either single-agent bevacizumab or XELOX plus bevacizumab until disease progression. An additional retrospective analysis was performed to define the prognostic value of tumour KRAS status on progression-free survival (PFS), overall survival (OS) and response rates. Methodology/Principal Findings: KRAS data (tumour KRAS status and type of mutation) were collected by questionnaire from participating centres that performed KRAS analyses. These data were then cross-referenced with efficacy da…
Standardized staining methods: Feulgen-Rossenbeck reaction for desoxyribonucleic acid and periodic acid-Schiff (PAS) procedure
2002
A project group working under the European Confederation of Laboratory Medicine (ECLM) presents recommendations for standardized procedures for the Feulgen-Rossenbeck-Schiff and the periodic acid-Schiff (PAS) reactions on cytological and histological material. The advantages and disadvantages of such standardized procedures are presented here in a preamble. Both users and manufacturers are encouraged to give their opinions with a view to achieving consensus on these procedures and on how further work on these lines may proceed.
Changes in fish mercury concentrations over 20 years in an acidified lake subject to experimental liming
2007
Abstract Lake Iso Valkjarvi (southern Finland, Europe) was divided in two with a plastic curtain in 1991. One half was neutralized with CaCO 3 , and the other acted as a control. Mercury concentrations of perch ( Perca fluviatilis ) and northern pike ( Esox lucius ) in the limed and control side of the lake were studied both before and after the treatment. Average Hg concentrations of perch and pike were 0.40 and 1.2 μg g −1 (ww) in the early 1980s and 0.25 and 0.72 μg g −1 (ww) a decade later at the time of liming. Ten years after the liming the Hg concentrations of perch in the limed and control sides of the lake were 0.21 and 0.28 μg g −1 (ww) and those of pike were 0.69 and 0.43 μg g −1…
Predation risk allocation or direct vigilance response in the predator interaction between perch (Perca fluviatilis L.) and pike (Esox lucius L.)?
2005
Predation risk allocation hypothesis predicts that a prey's response to predator depends on prey's previous experience on predator. Here we tested whether the group of three perch respond differentially to pike, predator of perch, depending on the timing of high constant (HC) and high unpredictable (HU) risk periods within low constant risk periods in short-term (10 h) experiments, and whether the response is stronger during a HU risk period than during a HC risk period. Perch clearly erected the dorsal fin in response to predation risk treatments (pike odour only, odour and visible pike). Decrease in activity and increase in shoaling behaviour were observed mainly during high risk periods.…
Studies on bucephalid digeneans parasitising molluscs and fishes in Finland I. Ecological data and experimental studies
1991
Two types of bucephalid cercariae are reported from the bivalve Anodonta anatina in two Finnish lakes. One, Type A, resembles in gross morphology the cercaria of Bucephalus polymorphus, and the other, Type B, resembles the cercaria of Rhipidocotyle campanula. Type A daughter-sporocysts develop more slowly, have a greater cercarial productivity and exhibit a differential diurnal rhythm to that of Type B. Cercariae of Type A have a shorter longevity than Type B and tend to encyst in the fins rather than the gill-arches of fish intermediate hosts. The main definitive host of Type A is pike Esox lucius and, in the case of Type B, perch Perca fluviatilis. Adults of Types A and B are morphologica…