Hypoxia-based habitat compression of tropical pelagic fishes   总被引：2，自引：0，他引：2  

ERIC D. PRINCE  C. PHILLIP GOODYEAR 《Fisheries Oceanography》2006,15(6):451-464

Large areas of cold hypoxic water occur as distinct strata in the eastern tropical Pacific (ETP) and Atlantic oceans as a result of high productivity initiated by intense nutrient upwelling. We show that this stratum restricts the depth distribution of tropical pelagic marlins, sailfish, and tunas by compressing the acceptable physical habitat into a narrow surface layer. This layer extends downward to a variable boundary defined by a shallow thermocline, often at 25 m, above a barrier of cold hypoxic water. The depth distributions of marlin and sailfish monitored with electronic tags and average dissolved oxygen (DO) and temperature profiles show that this cold hypoxic environment constitutes a lower habitat boundary in the ETP, but not in the western North Atlantic (WNA), where DO is not limiting. Eastern Pacific and eastern Atlantic sailfish are larger than those in WNA, where the hypoxic zone is much deeper or absent. Larger sizes may reflect enhanced foraging opportunities afforded by the closer proximity of predator and prey in compressed habitat, as well as by the higher productivity. The shallow band of acceptable habitat restricts these fishes to a very narrow surface layer and makes them more vulnerable to over‐exploitation by surface gears. Predictably, the long‐term landings of tropical pelagic tunas from areas of habitat compression have been far greater than in surrounding areas. Many tropical pelagic species in the Atlantic Ocean are currently either fully exploited or overfished and their future status could be quite sensitive to increased fishing pressures, particularly in areas of habitat compression.  相似文献   

Enhancement of transdermal delivery of phenylbutazone from liposomal gel formulations through deer skin     

R. JAYACHANDRA BABU  W. R. RAVIS  S. H. DURAN  J. SCHUMACHER  E. COX  R. STAHL  K. JONES  Y.‐J. JEAN LIN  Y.‐H. PHILLIP LEE  D. L. PARSONS  E. M. PORTMAN  S. C. R. BROWN 《Journal of veterinary pharmacology and therapeutics》2009,32(4):388-392

Phenylbutazone (PBZ) is a nonsteroidal anti‐inflammatory drug used in the treatment of chronic pain and arthritis. Topical and transdermal administration of PBZ would be beneficial in large animals in terms of minimizing gastro‐intestinal ulcerations and other side effects, easy administration to legs and joints and minimizing the dose to reduce systemic toxicity of the drug. A topical liposomal preparation with different concentrations of a mono‐substituted alkyl amide (MSA) and PBZ was formulated. The formulations were evaluated by in vitro skin‐permeation kinetics through deer skin using Franz diffusion cells. By increasing drug loading from 1% to 5% w/w, the steady‐state flux (μg/cm²/h) of PBZ was increased twofold (P < 0.001). Similarly, by increasing the MSA concentration from 0% to 4%, the steady‐state flux (μg/cm²/h) of PBZ was increased twofold (P < 0.001). Overall, by increasing the drug load and the use of an appropriate amount of the penetration enhancer, the steady‐state flux of PBZ through skin was increased fourfold (P < 0.001). MSA at both 2% and 4% w/w concentrations significantly increased the skin levels of PBZ as compared with control (P < 0.05). In conclusion, MSA served as an effective skin‐penetration enhancer in the liposomal gel of PBZ for deer.  相似文献   

Microsatellite DNA analysis and hydrodynamic modelling reveal the extent of larval transport and gene flow between management zones in an exploited marine fish (Glaucosoma hebraicum)     

OLIVER BERRY  PHILLIP ENGLAND  DAVID FAIRCLOUGH  GARY JACKSON  JIM GREENWOOD 《Fisheries Oceanography》2012,21(4):243-254

Determining the extent of dispersal in exploited marine fishes is essential for understanding their population dynamics and optimising management. The West Australian dhufish, Glaucosoma hebraicum, is a highly sought‐after, large and long‐lived reef‐dwelling species, endemic to south‐western Australia. Stock assessments indicate that this indicator species is overexploited. The fishery is managed using a zone‐based system, which implicitly assumes a high degree of demographic independence among zones. While tagging studies indicate limited movement of adult G. hebraicum, there is no understanding of the spatial scale of dispersal of its larvae and thus the true extent of interdependence of management zones. We analysed 13 microsatellite DNA loci to characterise the extent of gene flow, and conducted particle tracking simulations to model larval transport in this species. Genetic data demonstrated that some local recruitment was likely, but that on a broad scale gene flow between the management zones was extensive, and the entire fishery represents a single genetic stock. Hydrodynamic modelling predicted that the majority of dhufish larvae recruit from within the management zone where they are spawned, and that inter‐annual variation in current velocities has limited effect on the extent of larval transport. Because management zones are likely to be largely independent in terms of both larval and adult recruitment, heavy localised fishing pressure has the potential to reduce the abundance and reproductive capacity of this species in highly fished areas, but it should have limited impact on neutral genetic diversity.  相似文献   

Pharmacokinetic and pharmacodynamic evaluation of propofol administered to cats in a novel,aqueous, nano‐droplet formulation or as an oil‐in‐water macroemulsion1     

R. M. CLEALE  W. W. MUIR  A.‐C. WASELAU  M. W. LEHMANN  D. M. AMODIE  P. LERCHE 《Journal of veterinary pharmacology and therapeutics》2009,32(5):436-445

This study evaluated pharmacokinetic and pharmacologic properties of a novel, non‐lipid microemulsion, 1% w/v formulation of propofol to a conventional macroemulsion formulation of propofol (Rapinovet^®) in cats. The study utilized a two‐period crossover design with two treatments and 10 female, intact, purpose bred domestic shorthair cats. Cats were fitted with telemetry transmitters for direct measurement of arterial blood pressure, pulse rate, electrocardiogram (ECG, lead II), and body temperature. At least 7 days separated treatments. Orotracheal intubation was the clinical endpoint utilized to evaluate adequate depth of anesthesia. Blood samples were drawn from jugular vascular access ports before propofol treatment; 3, 5, 15, 25, 35, 45, and 60 min and then 2, 3, 6, 8, 12, 18, and 24 h after administration of propofol into a cephalic vein. Whole blood samples were assayed for propofol concentrations using a gas chromatography/mass spectrometry method validated for feline blood at a limit of quantification of 5 ng/mL. Pulse rate, ECG, heart rhythm, respiratory rate, systolic, diastolic and mean arterial blood pressures, SpO₂, and body temperature were monitored continuously during each anesthetic episode. Time to lateral recumbency, orotracheal intubation, and extubation, time to sternal recumbency during recovery, times to adverse events, and doses of propofol required for induction to anesthesia were documented. Cats required 6.96 ± 0.90 mg propofol/kg from the novel microemulsion formulation of propofol and 7.07 ± 1.55 mg propofol/kg from Rapinovet^® to achieve anesthesia adequate to allow orotracheal intubation (P > 0.05). Areas under the dose‐normalized propofol concentration by time curves (AUC_0‐LOQ) and maximum propofol concentrations (C_max) were equal for the novel microemulsion formulation of propofol and Rapinovet^® (P > 0.05). Effects of anesthesia induction doses on cardiorespiratory values were comparable between treatments, and consistent with known effects of propofol anesthesia. Results provide evidence that the novel microemulsion formulation of propofol and Rapinovet^® macroemulsion produced comparable pharmacodynamic, physiological, and pharmacokinetic responses in cats. The unique composition of the microemulsion formulation, and the presence of an antimicrobial preservative minimize the potential for bacterial contamination and prolong shelf life.  相似文献   

THE ROLE OF PROTECTIVE LEAD CLOTHING IN REDUCING RADIATION EXPOSURE RATES TO PERSONNEL DURING EQUINE BONE SCINTIGRAPHY     

PHILLIP F. STEYN  JOHN UHRIG 《Veterinary radiology & ultrasound》2005,46(6):529-532

Bone scintigraphy is often used in horses because of its sensitivity and noninvasive nature. A 99mTc labeled radiopharmaceutical is injected at a dose of between 5.7 and 7.3GBq. Images are acquired immediately postinjection and 2-4h post. People are often in the room with the horse during the acquisition process. Objectives of this study were to (a) document the radiation exposure rates at different distances from various sites of the horse at varying times post injection and (b) study the usefulness of wearing lead aprons to reduce exposure rates to personnel. Radiation exposure rates were measured in at three distances (at skin surface and at 30 and 100 cm from the skin) from three sites (shoulder, thorax, and pelvis) in 19 horses. Exposure rates were measured with and without shielding by a 0.5-mm lead equivalent apron during both the pool and delayed phases. A 0.5mm equivalent lead apron significantly decreases radiation exposure (P<0.05) at these three distances from the three sites during both image acquisition phases. Mean dose reduction factors from the lead apron range from 3.6 to 5.7.  相似文献   

Systemic and Local Effects Associated With Long-Term Epidural Catheterization and Morphine-Detomidine Administration in Horses     

ANNETTE M. SYSEL DVM  MS    R. SCOTT PLEASANT DVM  MS  Dipiomate ACVS    JOHN D. JACOBSON DVM  MS  Dipiomate ACVA    H. DAVID MOLL DVM  MS  Dipiomate ACVS    LORIN D. WARNICK DVM  PhD    D. PHILLIP SPONENBERG DVM  PhD  PETER EYRE BVMS  PhD  MRCVS 《Veterinary surgery : VS》1997,26(2):141-149

Objective — The purpose of this study was to determine the systemic and local effects associated with long-term epidural catheterization and epidural morphine-detomidine administration in horses. Study Design — Development of systemic or local effects was assessed by placing caudal epidural catheters in study horses and administering injections through the catheters every 12 hours for 14 days. Animals — Ten horses with epidural catheters that received daily injections; six uncatheterized horses presented for euthanasia. Methods — Horses received either 0.2 mg/kg morphine sulfate and 30 μg/kg detomidine hydrochloride or an equivalent volume of physiologic saline solution through epidural catheters. Systemic effects were compared between control and treatment horses by measuring physical parameters and hay and water consumption, as well as by evaluating major organs after euthanasia. Local effects were studied by examining cerebrospinal fluid and by grading representative samples of the spinal cord and surrounding tissues histologically for inflammation and fibrosis. Local effects were compared between control and treatment horses, as well as between catheter-ized (control plus treatment) horses and uncatheterized horses. Results — No significant difference was identified in daily variables or hay and water consumption between control and treatment horses. No growth was obtained from cerebrospinal fluid cultures. No significant difference in cerebrospinal fluid values or spinal tissue inflammation or fibrosis grades was shown between control and treatment horses. However, when compared with uncatheterized horses, cerebrospinal fluid red blood cell values were marginally higher and protein concentrations were significantly higher in the catheterized group. Lumbosacral and sacral spinal tissue segment inflammation grades, and sacral segment fibrosis grades were significantly higher in catheterized horses. Conclusions — Long-term epidural administration of a morphine-detomidine combination is not associated with apparent adverse systemic effects in horses. Localized inflammation and fibrosis seem to be catheter-related. Clinical Relevance — Potential systemic and local effects are important considerations with long-term administration of a morphine-detomidine combination through indwelling epidural catheters for alleviation of chronic musculoskeletal pain in horses.  相似文献   

NONINVASIVE ESTIMATION OF CENTRAL VENOUS PRESSURE IN ANESTHETIZED DOGS BY MEASUREMENT OF HEPATIC VENOUS BLOOD FLOW VELOCITY AND ABDOMINAL VENOUS DIAMETER     

NATHAN C. NELSON  WM TOD DROST  PHILLIP LERCHE  JOHN D. BONAGURA 《Veterinary radiology & ultrasound》2010,51(3):313-323

Determination of central venous pressure (CVP) is relevant to patients with right heart disease, hypovolemia, and following intravenous fluid therapy. We hypothesized that changes in CVP in dogs could be predicted by measurements of hepatic vein diameter, caudal vena cava (CVC) diameter, and hepatic venous flow velocities. Nine healthy American Foxhounds were anesthetized. Following baseline recordings, intravenous fluids were administered to increase CVP. Volume administration created treatment periods with CVP ranges of 5, 10, 15, 20, and 25 mm Hg. Flow velocities in the right medial hepatic vein were recorded using pulsed wave Doppler ultrasound. Hepatic vein, CVC, and aorta diameters were determined with B‐mode ultrasound. Variables were compared across the treatment periods by ANOVA for repeated measures. Relationships between CVP, Doppler, and B‐mode variables were evaluated using Spearman's rank correlations, multiple linear regression, and repeated measures linear regression. The a‐, S‐ and v‐wave velocities were augmented significantly with volume loading. The best part (semipartial) correlation coefficients predicting increasing CVP were identified with v‐wave velocity (0.823), S‐wave velocity (?0.800), CVC diameter (0.855), and hepatic vein diameter (0.815). Multiple linear regression indicated that CVP in this study could be predicted best by a combination of CVC and hepatic vein diameter and the v‐wave velocity (r=0.928). Ultrasound imaging identified gallbladder and pancreatic edema consistently, likely related to acute volume loading. These findings may be applicable in the assessment of volume status, dogs with right heart disease, and during serial monitoring of dogs receiving fluid or diuretic therapy.  相似文献   

Interactions between climate and population density in the episodic recruitment of bocaccio,Sebastes paucispinis,a Pacific rockfish     

RICHARD W. ZABEL  PHILLIP S. LEVIN  NICK TOLIMIERI  NATHAN J. MANTUA 《Fisheries Oceanography》2011,20(4):294-304

Climate strongly influences the population dynamics of many species, but intrinsic and extrinsic factors such as density‐dependence and anthropogenic impacts can confound the effects of climate. Further, the temporal scale of climate response is determined by the unique characteristics of a species’ life history, and determining the most appropriate climate indicator at the proper scale is a challenge faced by population ecologists. We focused on how climate influences juvenile survival of bocaccio (Sebastes paucispinis), a threatened Pacific rockfish, because its abundance has declined >90% in the last 25 years, ostensibly as the result of overfishing. Bocaccio recruitment is episodic, with strong recruitment events apparently related to climate conditions. We developed a sequence of models that related log of juvenile survival to the predictor variables population density and climate, as measured by the Northern Oscillation Index. A model that contained only population density as a predictor variable explained only 1.4% of the variance, while a model that included only climate indices explained 52%. Including density additively with climate did not improve model fit. However, a model that included an interaction between density and climate explained more than 68% of the variance. In addition, models that represented climate as monthly indices fit the juvenile survival data much better than those that averaged climate over 2‐ or 3‐month periods. Our results suggest that climate affects bocaccio recruitment as a series of pulses corresponding to particular life‐history events, with population density mediating the magnitude of the climate effect during the settlement stage.  相似文献   

Surgical Excision of Soft Tissue Fibrosarcomas in Cats   总被引：2，自引：1，他引：1  

ELLEN B. DAVIDSON DVM    CLARE R. GREGORY DVM  PHILLIP H. KASS DVM  PhD 《Veterinary surgery : VS》1997,26(4):265-269

Objective — The purpose of this study was to determine the tumor-free interval and survival times of cats who had one (group 1) or more (group 2) surgeries, or surgery and radiation therapy (RTH) (group 3) for treatment of soft tissue fibrosarcomas (FSA).
Study Design — Retrospective study.
Animals or Sample Population — 45 client-owned cats.
Methods — Medical records of cats with soft tissue FSA were examined. Vaccination and feline leukemia virus (FeLV) status, age, sex, breed, tumor location, number of surgeries, completeness of excision, and histopathological grade were evaluated to correlate with tumor-free interval and survival periods.
Results — Overall median tumor-free interval and survival times were 10 and 11.5 (range, 1 to 40) months. Median tumor-free interval and survival times were more than 16 months each in group 1, more than 5 and 13 months in group 2, and 4.5 and 9 months in group 3. Age, sex, breed, vaccination or FeLV status, tumor location, or histopathological grade did not affect median tumor-free interval or survival times ( P <.05). Cats with complete excisions had significantly longer median tumor-free interval (>16 versus 4 months) and survival time (>16 versus 9 months) than those with incomplete excisions ( P =.008). Radiation therapy did not seem to extend tumor-free interval and survival times ( P =.013). However, most group 3 cats had incomplete surgical excisions, resulting in recurrent or progressive disease.
Conclusions — Complete surgical excision of FSA in cats is possible and can be curative.
Clinical Relevance — Aggressive surgical excision with wide margins appears to contribute to extended tumor-free interval and survival times in cats with soft tissue FSA. Controlled prospective studies are needed to determine the efficacy of RTH in treatment.  相似文献   

Hemodynamic Responses of Horses to Anesthesia and Surgery, Before and After Administration of a Low Dose of Endotoxin     

ANN E. WAGNER DVM  MS  Diplomate ACVA  ACVP    COLIN I. DUNLOP BVSc  Diplomate ACVA    ETTA M. WERTZ DVM  MS  Diplomate ACVA    PHILLIP L. CHAPMAN PhD    GARY M. BAXTER VMD  MS  Diplomate ACVS  LISA S. KLOPP DVM 《Veterinary surgery : VS》1995,24(1):78-85

Seven horses, which were part of an investigation of the effect of endotoxin administration on vascular reactivity, were anesthetized on two separate occasions for surgical excision of 4-cm sections of palmar digital artery and vein. On the first occasion, the horses were given an infusion of 1 L 0.9% NaCl solution intravenously (IV) just before induction of anesthesia (control); on the second occasion, the horses received an infusion of 1 L 0.9% NaCl containing Escherichia coli endotoxin, 0.1 μg/kg (endotoxin). On both occasions, anesthesia was induced with xylazine, guaifenesin, and ketamine, and maintained with halothane in oxygen. Hemodynamic measurements were made with the horses under anesthesia immediately before beginning surgery (period 1), during skin incision (period 2), during dissection and excision of the vessels (period 3), during skin suturing (period 4), and after completion of surgery during bandaging (period 5). Hemoglobin concentration and mixed venous oxygen content were greater at all periods in horses that received endotoxin. Otherwise, there were no significant differences in hemodynamic parameters between control horses and horses administered endotoxin before beginning surgery (period 1). During surgery and bandaging, horses administered endotoxin had significantly higher heart rate (periods 3, 4, and 5), cardiac index (periods 3, 4, and 5), and oxygen delivery (periods 2, 3, 4, and 5) than did control horses, and mean arterial blood pressure (period 2) and systemic vascular resistance (periods 2, 3, 4, and 5) were less than in control horses. Compared with period 1, surgical stimulation in control horses was associated with increased mean arterial blood pressure and systemic vascular resistance (periods 2, 3, 4, and 5), but cardiac index and oxygen delivery were decreased (periods 3, 4, and 5). In contrast, horses administered endotoxin responded to surgical stimulation with increased mean arterial blood pressure (periods 2, 3, 4, and 5) and vascular resistance (periods 4 and 5), as well as a heart rate-induced increase in cardiac index (periods 2, 3, 4, and 5) compared with period 1; oxygen delivery also increased (periods 2, 3, 4, and 5) during surgery in the endotoxin group. This study documents some of the differences in the response to anesthesia and surgery between normal horses and those that have received endotoxin.  相似文献