Genetic control over survival in Pacific salmon (Oncorhynchus spp.): experimental evidence between and within populations of New Zealand chinook salmon (O. tshawytscha)

2003 ◽  
Vol 60 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Martin J Unwin ◽  
Michael T Kinnison ◽  
Nelson C Boustead ◽  
Thomas P Quinn

The ability to survive to adulthood and return to natal sites is a fundamental characteristic of anadromous salmonids, and low survival is likely to have prevented establishment of new populations within and outside their native range. We hypothesised that there is family-level genetic variation in traits contributing to survival and that populations evolve to maximise survival in response to prevailing local conditions. To test these predictions, we compared postrelease survival for chinook salmon families from two populations established in New Zealand in the 1900s. Both populations, Glenariffe Stream and Hakataramea River, had similar survival when released after translocation to a drainage familiar to neither population. However, Glenariffe families had higher survival than Hakataramea families when both populations were released from Glenariffe Stream, indicating a survival advantage for the local fish. In addition, there were significant correlations between survival rates for paternal half-sib families of Glenariffe fish and between survival rates for families released from the two locations. Family-specific survival was positively correlated with weight at release, but there were underlying genetic correlations unexplained by size. Taken together, these results suggest considerable genetic influence over survival and return of salmon and that population-specific adaptation can occur within 30 generations of establishment.


1997 ◽  
Vol 54 (6) ◽  
pp. 1246-1254 ◽  
Author(s):  
M J Unwin

Fry-to-adult survival rates for chinook salmon (Oncorhynchus tshawytscha) from Glenariffe Stream, a tributary of the Rakaia River, New Zealand, were estimated for fish of both natural and hatchery origin. Survival of naturally produced fry, most of which leave Glenariffe Stream within 24 h of emergence, averaged 0.079% (range 0.013-1.17%). For hatchery fish released at 8-12 months, standardised to a mean weight of 38 g, survival covaried with weight at release consistently across all brood years and averaged 0.34% (range 0.008-3.28%). Survival rates for hatchery fish were four times higher than for naturally produced fry, but were extremely poor relative to their size at release. Survival rates for fish of natural and hatchery origin were positively correlated, suggesting that recruitment of both stocks is primarily controlled by common influences within the marine environment, probably during the first winter at sea. Stock-recruitment analysis for the natural population showed little tendency for recruitment to increase with stock size, suggesting that marine survival rates may be density dependent. Although the reasons for the relatively poor survival of hatchery fish are unclear, the results provide a case study in which hatchery fish appear to have a poorer ``fitness to survive'' than their natural counterparts.



1987 ◽  
Vol 14 (4) ◽  
pp. 491 ◽  
Author(s):  
N Gilbert ◽  
K Myers ◽  
BD Cooke ◽  
JD Dunsmore ◽  
PJ Fullagar ◽  
...  

Shot samples of rabbits were collected over several years at 11 sites in Australia and one in New Zealand. At any one site, pregnancy rates and litter sizes vary both with age of mother and with time of year. Few rabbits become pregnant before the age of 19 weeks; pregnancy rate increases until the full adult rate is achieved about 27 weeks old. Litter size is also affected by age, adult litter size being reached by females at about 43 weeks old. Rates and timing of reproduction vary greatly from site to site in response to local conditions. The annual production of young per fully adult female is highest at Wairarapa, N.Z. (53 young) and lowest in the semiarid (17) and subalpine (15) environments. At six of the sites cohorts of marked rabbits provided estimates of seasonal survival rates; survival improves with age but becomes relatively constant in rabbits aged more than 24 weeks; survival patterns differ between sites. Life tables were constructed combining the information on reproduction and survival. Their possible usefulness is discussed.



1993 ◽  
Vol 50 (7) ◽  
pp. 1414-1421 ◽  
Author(s):  
Thomas P. Quinn ◽  
Martin J. Unwin

Chinook salmon (Oncorhynchus tshawytscha) were introduced to New Zealand, apparently from a single California population, and have been self-sustaining since about 1905. Salmon from the Waimakariri, Rakaia, Rangitata, and Waitaki rivers differed in various life history traits. The proportion of stream-type adults ranged from 29.1 to 75.6% in Rakaia and Waimakariri tributaries, respectively. Average age at maturity not only differed among the major rivers but also between two tributaries within the Rakaia River catchment. Length at age varied among rivers, the differences being most pronounced in older fish. Age structure and size at age combined to produce 91-, and 73-mm differences in mean length of males and females, respectively, among populations. Waitaki River salmon were not only long at age but also heavier for their length than other populations. The timing of entry into freshwater varied by over 1 mo between the Rakaia and Waitaki rivers, and median date of arrival on spawning grounds varied by 16 d between Rakaia and Waimakariri river tributaries. These life history traits are influenced, to varying degrees, by genetic and environmental factors. However, the suite of differences indicates that considerable adaptation to local conditions has occurred in about 20 generations.



Stroke ◽  
2001 ◽  
Vol 32 (suppl_1) ◽  
pp. 333-333
Author(s):  
Enrico Ascher ◽  
Prasad Gade ◽  
Anil Hingorani ◽  
Yilmaz Gunduz

96 Objective. Safety, effectiveness and cost issues of carotid endarterectomy (CEA) in the elderly patient have been debated because of limited life expectancy and presumably increased complications. We compared characteristics of two populations who underwent CEA: 80 or older (older group) and 65–79 year old patients (younger group). Methods. Medical and financial data were obtained by retrospective review of hospital charts and billing records. Recent follow-up was accomplished by telephone interview. Life-table and Chi-square tests were used for statistical analysis. We analyzed 109 CEAs performed in 101 older patients from 2/1/90 to 8/30/97 and 125 CEAs performed in 121 younger patients. Results. Comparing the older with younger groups, there were no differences in gender (50% male vs 59%), incidence of preop CVA (22% vs 17%) history of TIA (23% vs 25%), amaurosis fugax (6% vs 8%), hypertension (62% vs 60%), combined perioperative death and stroke rate (1.8% vs 1.7%) or other complications (11% vs 10%). Significant differences (p<0.05) were noted between older and younger groups in incidence of diabetes (17% in the older group vs 30%) , smoking (39% vs57%) and heart disease (48% vs 28%). Length of stay (2.8 in older group vs 3.0 days) or hospital cost including readmission for treatment of complications ($9,400 in older vs $7,842) were similar. Survival rates were not significantly different at the end of three years of follow up. Conclusions. Carotid endarterectomy can be performed in the elderly as safely and cost effectively as in the younger population.



Author(s):  
J. Ure

The region contains half the area of exotic forest in New Zealand and the major industries dependent thereon. Both are expanding rapidly to meet promising export markets. Local conditions are particularly favourable for this form of primary production and continued expansion is expected.



2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Angela Brenton-Rule ◽  
Daniel Harvey ◽  
Kevin Moran ◽  
Daniel O’Brien ◽  
Jonathon Webber

Abstract Background Podiatrists in New Zealand have a duty of care to assist patients in an emergency, and current cardiopulmonary resuscitation (CPR) certification is a requirement for registration. However, it is unknown how competent and confident podiatrists are in administering CPR and how they would respond in an emergency. Having a health professional who has a competent knowledge of CPR and skills in basic life support, can improve survival rates from sudden cardiac arrest. Therefore, the aim of this study was to survey New Zealand podiatrists to determine their CPR knowledge and qualifications; beliefs about the application of CPR; and perceptions of their competency in CPR. Methods This cross-sectional study used a web-based survey. Participants were New Zealand registered podiatrists with a current annual practising certificate. The 31-item survey included questions to elicit demographic information, CPR practice and attitudes, and CPR knowledge. Responses were collected between March and August 2020. Results 171 podiatrists responded to the survey. 16 % of the podiatrists (n = 28) had performed CPR in an emergency, with a 50 % success rate. Participants were predominantly female (n = 127, 74 %) and working in private practice (n = 140,82 %). Nearly half of respondents were younger than 40 years (n = 75,44 %) and had less than 10 years of clinical experience (n = 73, 43 %). Nearly all (n = 169,97 %) participants had received formal CPR training in the past two years, with 60 % (n = 105) receiving training in the past 12 months. Most respondents (n = 167,98 %) self-estimated their CPR ability as being effective, very effective, or extremely effective. Participants’ knowledge of CPR was variable, with the percentage of correct answers for CPR protocol statements ranging between 20 and 90 %. Conclusions This study provides the first insight into New Zealand podiatrists’ CPR knowledge and perceptions. Podiatrists were found to have high levels of CPR confidence but demonstrated gaps in CPR knowledge. Currently, New Zealand registered podiatrists require biennial CPR re-certification. However, resuscitation authorities in New Zealand and overseas recommend an annual update of CPR skills. Based on this study’s findings, and in line with Australia and the United Kingdom, the authors recommend a change from biennial to annual CPR re-certification for podiatrists in New Zealand. Trial registration The study was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12620001144909).



Forests ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 491 ◽  
Author(s):  
Irena Fundova ◽  
Tomas Funda ◽  
Harry X. Wu

Wood stiffness is an important wood mechanical property that predetermines the suitability of sawn timber for construction purposes. Negative genetic correlations between wood stiffness and growth traits have, however, been reported for many conifer species including Scots pine. It is, therefore, important that breeding programs consider wood stiffness and growth traits simultaneously. The study aims to (1) evaluate different approaches of calculating the dynamic modulus of elasticity (MOE, non-destructively assessed stiffness) using data from X-ray analysis (SilviScan) as a benchmark, (2) estimate genetic parameters, and (3) apply index selection. In total, we non-destructively measured 622 standing trees from 175 full-sib families for acoustic velocity (VEL) using Hitman and for wood density (DEN) using Resistograph and Pilodyn. We combined VEL with different wood densities, raw (DENRES) and adjusted (DENRES.TB) Resistograph density, Pilodyn density measured with (DENPIL) and without bark (DENPIL.B), constant of 1000 kg·m−3 (DENCONST), and SilviScan density (DENSILV), to calculate MOEs and compare them with the benchmark SilviScan MOE (MOESILV). We also derived Smith–Hazel indices for simultaneous improvement of stem diameter (DBH) and wood stiffness. The highest additive genetic and phenotypic correlations of the benchmark MOESILV with the alternative MOE measures (tested) were attained by MOEDENSILV (0.95 and 0.75, respectively) and were closely followed by MOEDENRES.TB (0.91 and 0.70, respectively) and MOEDENCONST and VEL (0.91 and 0.65, respectively for both). Correlations with MOEDENPIL, MOEDENPIL.B, and MOEDENRES were lower. Narrow-sense heritabilities were moderate, ranging from 0.39 (MOESILV) to 0.46 (MOEDENSILV). All indices revealed an opportunity for joint improvement of DBH and MOE. Conclusions: MOEDENRES.TB appears to be the most efficient approach for indirect selection for wood stiffness in Scots pine, although VEL alone and MOEDENCONST have provided very good results too. An index combining DBH and MOEDENRES.TB seems to offer the best compromise for simultaneous improvement of growth, fiber, and wood quality traits.



2000 ◽  
Vol 78 (11) ◽  
pp. 1420-1429 ◽  
Author(s):  
Theresa M Culley

Few studies of inbreeding depression have focused on species producing both showy, chasmogamous (CH) flowers and self-pollinated, cleistogamous (CL) flowers. The goals of this investigation were to measure the level of inbreeding depression in the North American violet, Viola canadensis L., and to determine if any fitness differences were linked to floral type (CH versus CL) rather than to cross type (self versus outcross). Hand pollinations were carried out to produce self- and outcross-pollinated CH progeny, and CL seeds were also collected. In a greenhouse, selfed and outcrossed CH flowers produced similar numbers of seeds, and both types of progeny had similar survival rates and comparable numbers of CH flowers, although outcrossed CH progeny had 14% greater vegetative biomass than selfed CH progeny. The level of inbreeding depression in V. canadensis was low, indicating that there may be few drawbacks to selfing in this species. A comparison of CL and self-pollinated CH progeny showed that, although there were differences in CH flower number, overall fitness differences were minimal. The similar performance of selfed (CL and CH) and outcrossed progeny in early life-history stages of V. canadensis suggests a history of inbreeding in the population.Key words: cleistogamy, inbreeding depression, outcrossing, selfing, Viola canadensis.



1988 ◽  
Vol 120 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Norma E. Sanchez ◽  
Jerome A. Onsager

AbstractA combination of published techniques provided point estimates of life history parameters for two natural field populations of Melanoplus sanguinipes (F.) in crested wheatgrass pastures. Stage-specific survival rates averaged 0.4798, 0.2261, 0.7628, and 0.6903 for egg, instars I–III combined, instar IV, and instar V, respectively. Daily survival rates of adults averaged 0.9702, but were slightly lower for females than for males. Estimated duration of nymphal instars averaged 8.4 days, the adult preoviposition period averaged 13.3 days, and adult longevity averaged 26.7 and 36.3 days in the two populations. Oviposition rates were estimated for up to four successive ovipositions, and net replacement rates of populations also were estimated. Neither population replaced itself, indicating that potential capacities for increase were not approached under conditions of these studies.



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