Variability in the performance of juvenile Chinook salmon is explained primarily by when and where they resided in estuarine habitats          下载免费PDF全文

Paul Chittaro  Lyndal Johnson  David Teel  Paul Moran  Sean Sol  Kate Macneale  Richard Zabel 《Ecology of Freshwater Fish》2018,27(3):857-873

Estuarine habitats provide rearing opportunities for the juvenile life stage of anadromous fishes. Because survival is positively correlated with juvenile performance, these estuarine habitats play an important role in population abundance and productivity. To provide information for the recovery of several depressed stocks of Chinook salmon in the Columbia River Basin, we sought to identify the factors that explain variability in performance. Using otolith‐derived estimates of juvenile somatic growth rate as an index of recent performance, we observed a negative nonlinear relationship between growth rate and day of year, and a decreasing and increasing trend of growth rate over the 8 years of this study and distance from the river mouth respectively. Using a generalised linear modelling approach, we found that variability in juvenile somatic growth rate was best explained by where and when individuals were collected, their body size, contaminant loads, stock of origin, and whether a fish was hatchery produced or unmarked. Lastly, we argue that a considerable improvement to the growth rate of juveniles in estuarine habitats is physiologically possible. The results of this 8‐year study provide a baseline of the performance of juvenile Chinook salmon to evaluate habitat restoration programs and to compare against future anthropogenic conditions.  相似文献   

Has bovine somatotropin (BST) an effect upon drug disposition? Comparative studies in goats and cattle with sulphadimidine and antipyrine after parenteral administration of BST,zeranol and proligestone     

R. F. WITKAMP  S. M. NIJMEIJER  C. T. M. VAN DUIN  M. M. BEVERS  TH. WENSING†  H. VAN GOGH  A.S.J.P.A.M. VAN MIERT 《Journal of veterinary pharmacology and therapeutics》1989,12(2):163-178

Daily subcutaneous BST injection in lactating cows, bulls and castrated male dwarf goats did not induce significant changes in the pharmacokinetic parameters of antipyrine (AP) and sulphadimidine (SDD). Similarly, no changes were obtained after injection of slow-release BST formulations in lactating cows and non-lactating female goats. In contrast to androgenic hormones, both zeranol and proligestone had no effect upon the disposition of AP and SDD, although both synthetic hormones did induce enhanced plasma somatotropin concentrations. In goats, metabolic effects induced by zeranol and BST included significant reductions in plasma urea values, whereas plasma creatinine levels were somewhat lower after daily BST administration.  相似文献   

Cation-ratio and accelerator radiocarbon dating of rock varnish on mojave artifacts and landforms     

Dorn RI  Bamforth DB  Cahill TA  Dohrenwend JC  Turrin BD  Donahue DJ  Jull AJ  Long A  Macko ME  Weil EB  Whitley DS  Zabel TH 《Science (New York, N.Y.)》1986,231(4740):830-833

The first accelerator radiocarbon dates of rock varnishes are reported along with potassium/argon ages of lava flows and conventional radiocarbon dates of pluvial lake shorelines, in an empirical calibration of rock varnish K(+) + Ca(2+)/Ti(4+) ratios with age in the Mojave Desert, eastern California. This calibration was used to determine the cation-ratio dates of 167 artifacts. Although cation-ratio dating is an experimental method, some dates suggest human occupation of the Mojave Desert in the late Pleistocene.  相似文献   

Self-trapping of dark incoherent light beams     

Z Chen  M Mitchell  M Segev  TH Coskun  DN Christodoulides 《Science (New York, N.Y.)》1998,280(5365):889-892

"Dark beams" are nonuniform optical beams that contain either a one-dimensional (1D) dark stripe or a two-dimensional (2D) dark hole resulting from a phase singularity or an amplitude depression in their optical field. Thus far, self-trapped dark beams (dark solitons) have been observed using coherent light only. Here, self-trapped dark incoherent light beams (self-trapped dark incoherent wavepackets) were observed. Both dark stripes and dark holes nested in a broad partially spatially incoherent wavefront were self-trapped to form dark solitons in a host photorefractive medium. These self-trapped 1D and 2D dark beams induced refractive-index changes akin to planar and circular dielectric waveguides. The experiments introduce the possibility of controlling high-power coherent laser beams with low-power incoherent light sources such as light emitting diodes.  相似文献   

An amylose antiparallel double helix at atomic resolution     

Hinrichs W  Büttner G  Steifa M  Betzel C  Zabel V  Pfannemüller B  Saenger W 《Science (New York, N.Y.)》1987,238(4824):205-208

In the crystal structure of the polyiodide complex (p-nitrophenyl-alpha-maltohexaose(2)) . Ba(I(3))(2) . 22H(2)O, the maltohexaose units form an antiparallel, left-handed double helix with O-2 ... O-3 and O-6 ... O-6 hydrogen bonding and a central cavity that encloses two triiodide units. This structure contrasts with the parallel, left-handed double helix with no central cavity proposed for the A-and B-starch helix and the left-handed single helix in V-amylose and may be relevant for the stabilization of glycogen Structure.  相似文献   

Circulating antibody response to Eimeria tenella oral and subcutaneous infections in chickens     

Nazik Abu Ali  M. Movsesijan  A. Sokolić  Zabel Tanielian 《Veterinary parasitology》1976,1(4):309-316

Immune responses in chickens to Eimeria tenella using oral and subcutaneous routes of infection were investigated. The results obtained indicated that sporulated oocysts inoculated subcutaneously in doses up to 50 000 oocysts per bird were not fatal to 21-day-old chicks. Subcutaneous inoculation of oocysts was found to be less immunogenic than oral administration. The dynamics of the antibody responses were different for the two routes of infection. Orally administered oocysts stimulated a dramatic primary increase in the serum antibody titre with a tendency towards a decrease in the titre 14 days post infection irrespective of second infections at that time. However, a third oral dose of oocysts stimulated a slight increase in antibody titre. Two doses of oocysts injected subcutaneously induced only a slight increase in serum antibody titre. Such a low titre was dramatically increased following a subsequent oral dose of oocysts. Antibodies specific to E. tenella are IgM and IgG immunoglobulins. IgA immunoglobulin was not investigated.  相似文献   

Congenital porto-systemic shunts in sixteen dogs and three cats   总被引：1，自引：0，他引：1  

J. ROTHUIZEN  TH. S. G. A. M. VAN DEN  INGH  G. VOORHOUTM†  R. J. T. VAN DER  LUER W. WOUDA 《The Journal of small animal practice》1982,23(2):67-81

Congenital porto-systemic shunts in sixteen dogs and three cats are described. A major symptom was hepato-encephalopathy. In most cases diagnosis was based on elevated venous ammonia levels, abnormal ammonia tolerance and results of operative mesenteric portography. Clinical signs, laboratory findings, results of portography, and pathologic findings in the liver and the central nervous system are described. A diagnostic schedule is proposed to aid in recognition of this syndrome.  相似文献   

The efficacy of cetirizine hydrochloride on the pruritus of cats with atopic dermatitis: a randomized,double‐blind,placebo‐controlled,crossover study     

Kerstin Wildermuth  Sonja Zabel  Rod A. W. Rosychuk 《Veterinary dermatology》2013,24(6):576-e138

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A randomized, double-blind, placebo-controlled study to evaluate the effect of EFF1001, an Actinidia arguta (hardy kiwi) preparation, on CADESI score and pruritus in dogs with mild to moderate atopic dermatitis     

Rosanna Marsella  Linda Messinger  Sonja Zabel  Rod Rosychuck  Craig Griffin  Patti Orozco Cronin  Gil Belofsky  Julie Lindemann  Dean Stull 《Veterinary dermatology》2010,21(1):50-57

Canine atopic dermatitis (AD) is common and new therapies are beneficial. This multicentric, randomized, double-blind, placebo-controlled study tested the efficacy of Actinidia arguta (hardy kiwi) (EFF1001) in dogs with mild/moderate AD. The study was divided into two stages. Stage 1 lasted 6 weeks. In the first 2 weeks prednisolone [days 1–3: 0.2 mg/kg twice daily (BID), days 4–14: 0.2 mg/kg every other day (EOD)] was administered. Responsive dogs were placed on prednisolone 0.2 mg/kg EOD + assigned test article [either placebo or EFF1001 (30 mg/kg)] once daily for 4 weeks. Stage 1 responders were advanced to stage 2, which involved 4 weeks of just EFF1001. Clinicians scored lesions using Canine Atopic Dermatitis Extent and Severity Index (CADESI) and owners scored pruritus using a Pruritus Visual Analogue Scale. Seventy-seven dogs were enrolled, 76 were randomized on day 14, and 57 (57/76 = 75%) completed stage 1 (27 in EFF1001 and 30 in placebo). At the end of stage 1, 35 of 57 dogs (35/57 = 61%) responded (18 in EFF1001 and 17 in placebo) and advanced to stage 2. At completion of stage 1, CADESI scores did not significantly differ between groups while pruritus decreased in EFF1001 group and approached significance. At completion of stage 2, 19 dogs (19/35 = 54%) responded (15/19 = 79% had received EFF1001 and 4/19 = 21% placebo in stage 1). After completing stage 2, dogs placed on EFF1001 throughout the study were 3.5 times more likely to either maintain or improve scores than those that started it in stage 2. It is concluded that EFF1001 is beneficial adjunctive therapy after prolonged use.  相似文献   

Measurement of C‐peptide concentrations and responses to somatostatin,glucose infusion,and insulin resistance in horses     

F. TÓTH  N. FRANK  T. MARTIN‐JIMÉNEZ  S. B. ELLIOTT  R. J. GEOR  R. C. BOSTON 《Equine veterinary journal》2010,42(2):149-155

Reasons for performing study: Hyperinsulinaemia is detected in horses with insulin resistance (IR) and has previously been attributed to increased pancreatic insulin secretion. Connecting peptide (C‐peptide) can be measured to assess pancreatic function because it is secreted in equimolar amounts with insulin and does not undergo hepatic clearance. Hypothesis: A human double antibody radioimmunoassay (RIA) detects C‐peptide in equine serum and concentrations would reflect responses to different stimuli and conditions. Methods: A validation procedure was performed to assess the RIA. Six mature mares were selected and somatostatin administered i.v. as a primed continuous rate infusion, followed by 50 nmol human C‐peptide i.v. Insulin and C‐peptide concentrations were measured in horses (n = 6) undergoing an insulin‐modified frequently sampled i.v. glucose tolerance test, and in horses with insulin resistance (n = 10) or normal insulin sensitivity (n = 20). Results: A human RIA was validated for use with equine sera. Endogenous C‐peptide secretion was suppressed by somatostatin and median (range) clearance rate was 0.83 (0.15–1.61) ml/min/kg bwt. Mean ± s.d. C‐peptide‐to‐insulin ratio significantly (P = 0.004) decreased during the glucose tolerance test from 3.60 ± 1.95 prior to infusion to 1.03 ± 0.18 during the first 20 min following dextrose administration. Median C‐peptide and insulin concentrations were 1.5‐ and 9.5‐fold higher, respectively in horses with IR, compared with healthy horses. Conclusions: Endogenous C‐peptide secretion decreases in response to somatostatin and increases after dextrose infusion. Results suggest that relative insulin clearance decreases as pancreatic secretion increases in response to dextrose infusion. Hyperinsulinaemia in insulin resistant horses may be associated with both increased insulin secretion and decreased insulin clearance. Potential relevance: Both C‐peptide and insulin concentrations should be measured to assess pancreatic secretion and insulin clearance in horses.  相似文献