scholarly journals Population dynamics of the Kaminuriak caribou herd, 1968 - 1985

Rangifer ◽  
1986 ◽  
Vol 6 (2) ◽  
pp. 159 ◽  
Author(s):  
Douglas C. Heard ◽  
George W. Calef
Keyword(s):  
Population Dynamics ◽  
Post Partum ◽  
Survival Rates ◽  
Fold Increase ◽  
Birth Rates ◽  
Population Processes ◽  
Birth Peak ◽  
As If

The Kaminuraik caribou herd apparently declined from about 120 000 animals in 1950 to 63 000 in 1968. Beginning in 1968 documentation of herd trend was based on the estimate of the number of breeding (pregnant and post-partum) females on the calving ground during the birth peak. It appeared as if we understood the basic population processes responsible for the decline when we correctly predicted a drop from 14 800 breeding females in 1977 to 13 000 in 1980. However a three-fold increase, to 41 000 breeding females in 1982, and continued growth thereafter, was unanticipated. Most of that increase must have resulted from an immigration of cows to the herd's traditional calving ground around Kaminuriak Lake, although increased birth rates, and increased survival rates also contributed to herd growth. Immigrant cows probably came from the northeastern mainland of the NWT

Persistence of giants: population dynamics of the limpet Scutellastra laticostata on rocky shores in Western Australia

2020 ◽  
Vol 646 ◽  
pp. 79-92
Author(s):  
RE Scheibling ◽  
R Black
Keyword(s):  
Population Dynamics ◽  
Western Australia ◽  
Size Structure ◽  
Survival Rates ◽  
Maximum Size ◽  
High Rate ◽  
Adult Survival ◽  
Rocky Shores ◽  
Adult Size ◽  
Decadal Time Scale

Population dynamics and life history traits of the ‘giant’ limpet Scutellastra laticostata on intertidal limestone platforms at Rottnest Island, Western Australia, were recorded by interannual (January/February) monitoring of limpet density and size structure, and relocation of marked individuals, at 3 locations over periods of 13-16 yr between 1993 and 2020. Limpet densities ranged from 4 to 9 ind. m-2 on wave-swept seaward margins of platforms at 2 locations and on a rocky notch at the landward margin of the platform at a third. Juvenile recruits (25-55 mm shell length) were present each year, usually at low densities (<1 m-2), but localized pulses of recruitment occurred in some years. Annual survival rates of marked limpets varied among sites and cohorts, ranging from 0.42 yr-1 at the notch to 0.79 and 0.87 yr-1 on the platforms. A mass mortality of limpets on the platforms occurred in 2003, likely mediated by thermal stress during daytime low tides, coincident with high air temperatures and calm seas. Juveniles grew rapidly to adult size within 2 yr. Asymptotic size (L∞, von Bertalanffy growth model) ranged from 89 to 97 mm, and maximum size from 100 to 113 mm, on platforms. Growth rate and maximum size were lower on the notch. Our empirical observations and simulation models suggest that these populations are relatively stable on a decadal time scale. The frequency and magnitude of recruitment pulses and high rate of adult survival provide considerable inertia, enabling persistence of these populations in the face of sporadic climatic extremes.

scholarly journals POPULATION DYNAMICS ON ONGOLE GRADE CATTLE IN KEBUMEN REGENCY - CENTRAL JAVA

2016 ◽  
Vol 41 (4) ◽  
pp. 224
Author(s):  
J. Rohyan ◽  
S. Sutopo ◽  
E. Kurnianto
Keyword(s):  
Population Dynamics ◽  
Post Partum ◽  
Natural Increase ◽  
Survey Respondent ◽  
Replacement Rate ◽  
Potential Output ◽  
Central Java ◽  
Weaning Age ◽  
Livestock Farmers ◽  
Materials Used

The objectiveof this study was to elucidatereproductive characteristics, potential output and dynamics population of Ongole Gradecattle in Kebumen Regency, Province of Central Java. The studywasconductedfromSeptemberto November 2015.The materials used in the study were165 farmers as respondentshavingOngole Gradecattle. The research method used was survey. Respondent samples were taken from five districts in which the location was determined by using purposive sampling. Data were collected through direct interviews with livestock farmers as respondents. The analysis used wasdescriptive analysis. The results showed that the age at first mating was 26.87 month, S/C was 1.64, post-partum mating was4.52 month, weaning age was 3.97 month, calving interval was 14.32 month, and the birth rate topopulation was45.5%. Reproductive efficiency value was 91.8%, natural increase was 44.68%, and net replacement rate of bull and heifer were 1,209% and 253%,respectively, andtotal output 44.11%. Population dynamics of Ongole Gradecattle from 2009 to 2014 fluctuated with average growthwas -4.84%. In 2019, cow population of Ongole Gradewasestimated about 68.381 heads. In conclusion Kebumen Regencyhasa relatively high potential output of Ongole Gradecattle thatis44.11% and population dynamics from 2010 to 2014 fluctuated with average of decrease growth is 4.84%. Estimation of cow’s population of Ongole Grade cattle willincrease 16.7% per year. 

The population dynamics of aphids on fire weed: a comparison of local populations and metapopulations

1978 ◽  
Vol 56 (12) ◽  
pp. 2554-2564 ◽  
Author(s):  
John F. Addicott
Keyword(s):  
Population Dynamics ◽  
Spatial Heterogeneity ◽  
Rocky Mountains ◽  
Median Number ◽  
Marked Variation ◽  
High Frequencies ◽  
Local Populations ◽  
Epilobium Angustifolium ◽  
Population Processes ◽  
Different Levels

Local populations of four species of aphids (Macrosiphum Valerianae, Aphis varions, A. helianthi, and A. salicariae) occur on shoots of fireweed (Epilobium angustifolium) in the Rocky Mountains of Colorado, U.S.A. Through exhaustive and repeated nondestructive sampling of the local populations on over 3800 shoots of fireweed, information was obtained on the dynamics of both the local populations and the metapopulation of each species. The dynamics of the metapopulation were analyzed in terms of the frequency of shoots occupied by aphids and the median number of aphids per occupied shoot. There were significant differences between species in both parameters, but high densities were not necessarily accompanied by high frequencies. Local populations were initiated throughout the summer, and there was marked variation in the duration and size of these populations. Most populations lasted only a few weeks, but others lasted up to 14 weeks. This turnover of local populations within the metapopulation implies that local populations must be studied in order to understand the dynamics of the metapopulation. There is a discussion of the relationships between population processes occurring at different levels of spatial heterogeneity.

scholarly journals Long-term trends in wild-capture and population dynamics point to an uncertain future for captive elephants

2019 ◽  
Vol 286 (1899) ◽  
pp. 20182810 ◽  
Author(s):  
John Jackson ◽  
Dylan Z. Childs ◽  
Khyne U. Mar ◽  
Win Htut ◽  
Virpi Lummaa
Keyword(s):  
Population Dynamics ◽  
Wild Populations ◽  
Birth Rates ◽  
As Species ◽  
In Captivity ◽  
Elephant Population ◽  
Long Term Trends ◽  
Uncertain Future ◽  
Primary Focus

Maintaining sustainable populations in captivity without supplementation through wild-capture is a major challenge in conservation that zoos and aquaria are working towards. However, the capture of wild animals continues for many purposes where conservation is not the primary focus. Wild-capture hinders long-term conservation goals by reducing remaining wild populations, but the direct and long-term indirect consequences of wild-capture for captive population viability are rarely addressed using longitudinal data. We explored the implications of changes in wild-capture on population dynamics in captivity over 54 years using a multi-generational studbook of working Asian elephants ( Elephas maximus ) from Myanmar, the largest remaining captive elephant population. Here we show that population growth and birth rates declined between 1960 and 2014 with declines in wild-capture. Importantly, wild-caught females had reduced birth rates and a higher mortality risk. However, despite the disadvantages of wild-capture, the population may not be sustainable without it, with immediate declines owing to an unstable age-structure that may last for 50 years. Our results highlight the need to assess the long-term demographic consequences of wild-capture to ensure the sustainability of captive and wild populations as species are increasingly managed and conserved in altered or novel environments.

scholarly journals Population dynamics of rice leaffolders (Lepidoptera: Pyralidae) and their natural enemies in irrigated rice in the Philippines

1999 ◽  
Vol 89 (5) ◽  
pp. 411-421 ◽  
Author(s):  
J. de Kraker ◽  
A. van Huis ◽  
K.L. Heong ◽  
J.C. van Lenteren ◽  
R. Rabbinge
Keyword(s):  
Population Dynamics ◽  
Natural Enemies ◽  
Natural Enemy ◽  
Survival Rates ◽  
The Philippines ◽  
Cnaphalocrocis Medinalis ◽  
Irrigated Rice ◽  
Larval Stages ◽  
Ovipositional Preference ◽  
Rice Leaffolders

AbstractPopulations of rice leaffolders and their natural enemies were studied in eight crops of irrigated rice in Laguna Province, the Philippines. The rice leaffolder complex consisted of three species: Cnaphalocrocis medinalis (Guenée), Marasmia patnalis Bradley and M. exigua Butler. Leaffolder population dynamics were characterized by an egg peak at maximum tillering and a broad larval peak around booting stage. Peak densities ranged from 0.2 to 2.0 larvae per hill. Most larvae originated from immigrant moths and there was no substantial second generation. The seasonal percentage egg parasitism by Trichogramma sp. ranged from 0 to 27%, and percentage larval parasitism from 14 to 56%. The braconid Macrocentrus philippinensis Ashmead was the most commonly reared larval parasitoid. Forty natural enemy taxa that may attack rice leaffolders were identified from suction and sweepnet samples: 24 predator taxa and 16 parasitoid taxa. The estimated survival rates from leaffolder egg to larval stages and between larval stages showed large variation between rice crops, but were not clearly correlated with observed levels of parasitism, natural enemy abundance, or natural enemy to leaffolder ratios. It is suggested that the generally low densities of rice leaffolders in Philippine transplanted rice are caused by their ovipositional preference for crops at the maximum tillering stage, allowing for only one generation, and by high immature mortality caused by the abundant and diverse complex of natural enemies.

The distribution indices of erythrocytes: which one for acute ischemic stroke?

2019 ◽  
Vol 45 (1) ◽  
pp. 65-75
Author(s):  
Nahide Ekici Günay ◽  
Nurullah Günay
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Linear Relationship ◽  
Survival Rates ◽  
Prognostic Significance ◽  
Fold Increase ◽  
Reference Intervals ◽  
Stroke Severity ◽  
Severity Scores ◽  
Poor Outcomes

Abstract Background The erythrocytes distribution indices are reported from same histogram but they have different reference intervals and calculated by distinct measurements. Objectives To explore whether the RDW-CV and RDW-SD values may predictive and prognostic significance in ischemic stroke patients and to clarify the relation each of these indices with stroke severity and 3-months survival. Materials and methods Cumulative survival rates were calculated with the Kaplan-Meier method, and life curves were compared to RDW-CV, RDW-SD quartiles. The risk factors were described with a multivariable cox proportional hazard model. Results In acute ischemic stroke, RDW-CV was more specific and RDW-SD was more sensitive (92% vs. 80%) (52% vs. 48%). RDW-CV values higher than 14.7% are associated with 11-fold increase in the risk of stroke; and the level of RDW-CV does show a linear relationship with the severity of stroke. However, when we evaluated RDW-SD, higher 43.55 fL RDW-SD values was have 16-fold increase in severity of stroke and have a relatively high linear relationship with stroke severity scores to RDW-CV. Conclusions RDW-CV and RDW-SD levels have different prognostic poor outcomes for interpreting in ischemic stroke events approach and these should be used alone and comparatively with the AIS predictive and prognostic approach.

Effects of Different Foliar-applied Nitrogen Fertilizers on Balsam Woolly Aphid

1973 ◽  
Vol 3 (1) ◽  
pp. 122-139 ◽  
Author(s):  
J. Roderick Carrow ◽  
Robert E. Betts
Keyword(s):  
Ammonium Nitrate ◽  
Survival Rates ◽  
Calcium Nitrate ◽  
Fold Increase ◽  
Nitrogen Fertilizers ◽  
Controlled Environment ◽  
Acid Diet ◽  
Woolly Aphid ◽  
Urea Ammonium Nitrate ◽  
Induced Changes

Balsam woolly aphids were reared on young grand fir trees maintained in controlled environment or outdoors. Solutions of various nitrogen fertilizers were applied repeatedly to the trees and the effects on aphids and bark amino acids were studied. On trees fertilized with ammonium nitrate or a sequence of compounds, aphid population growth was less than on trees fertilized with urea or potassium ammonium nitrate. On urea-fertilized trees, populations multiplied 16.5 times in five generations, compared with a 5.7-fold increase on unfertilized trees and a 1.4-fold increase on ammonium nitrate-fertilized trees. These differences resulted from effects of these nutrients on aphid life history. Urea promoted aphid establishment and reproduction, whereas ammonium nitrate affected these processes, as well as survival, adversely. The highest establishment and survival rates resulted from potassium ammonium nitrate.These differences may be related to fertilizer-induced changes in the amino acid diet of the aphid. Thin layer electrophoresis and chromatography revealed that urea, ammonium nitrate, and calcium nitrate each increased arginine concentrations in the bark, the highest levels resulting from ammonium nitrate. Traces of phenylalanine and asparagine, found in other treatments, were absent from trees fertilized with ammonium nitrate during June.

scholarly journals The GH/IGF-I axis in the brushtail possum (Trichosurus vulpecula) pouch young

2003 ◽  
Vol 176 (2) ◽  
pp. 219-225 ◽  
Author(s):  
MC Saunders ◽  
RT Gemmell ◽  
JD Curlewis
Keyword(s):  
Mrna Expression ◽  
Fetal Liver ◽  
Post Partum ◽  
Fold Increase ◽  
High Plasma ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Igf I ◽  
Plasma Gh ◽  
Igfbp 3

Plasma and pituitary GH concentrations and liver GH receptor (GHR), IGF-I and IGF-binding protein-3 (IGFBP-3) mRNA expression were determined in brushtail possum (Trichosurus vulpecula) pouch young aged 12-150 days post-partum and in adults. Mean plasma GH concentrations were highest, measuring around 150 ng/ml, from 12 to 100 days post-partum, and thereafter declined so that by 150 days post-partum levels were not significantly different from those in adults (10.8+/-1.8 ng/ml (S.E.M.)). In contrast to plasma levels, pituitary GH content increased markedly throughout pouch life, with an 87-fold increase between 12 and 150 days post-partum. However, when expressed per gram body weight, pituitary content was relatively constant between 25 and 150 days post-partum, indicating that the decline in plasma GH after 100 days post-partum was not due to decreased synthesis and/or storage of GH in the pituitary gland. Expression of GHR, IGF-I and IGFBP-3 mRNAs was determined by semi-quantitative RT-PCR. Liver GHR and IGF-I mRNA expression were low at 12 and 25 days post-partum and did not show sustained and significant increases (P<0.05) until 125 and 150 days post-partum. IGFBP-3 expression was also low at 12 days post-partum but then increased rapidly to a maximum at 50 days post-partum and thereafter declined. For all three mRNAs, liver expression at day 150 was not significantly different from that in adults. These patterns of gene expression for GHR and IGF-I suggest that the possum liver is resistant to the high plasma GH concentrations during early pouch life and in this way is similar to the fetal liver of some eutherian mammals.

Antithrombin Deficiency in Pregnancy.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1879-1879
Author(s):  
Retter J. Andrew ◽  
Hunt J. Beverley
Keyword(s):  
Caesarean Section ◽  
Post Partum ◽  
Case Series ◽  
Fold Increase ◽  
First Trimester ◽  
Antithrombin Deficiency ◽  
Sagittal Sinus ◽  
Asymptomatic Patients ◽  
Estimated Blood Loss ◽  
In Pregnancy

Abstract Background: During pregnancy untreated antithrombin deficiency is associated with up to a 50% risk of venous thromboembolism (VTE) and a relative risk of pregnancy loss of 2.1 with a 5-fold increase in stillbirths. Thus thromboprophylaxis is widely used, but little data is available to select type, dose & duration of anticoagulation. Method: We performed a retrospective, single centre observational study of our antithrombin deficient pregnancies since 1996. Results: There were 9 pregnancies in 8 women; median age at conception 33 (age-range 19–37). They separated into 3 groups (1) 4 asymptomatic patients diagnosed on family screening. They received unmonitored enoxaparin 40mg until 16 weeks then 40mg BD. (2) 2 with previous VTE, received intermediate dose enoxaparin (1mg/kg), increased to BD at 16 weeks. Monitoring was done to maintain an anti-Xa trough of <0.12 iu/ml and peak <0.8iu.ml. (3) 2 referred after presenting with VTE in pregnancy. They received enoxaparin 1mg/kg BD and the same monitoring These included a known antithrombin deficient woman, referred in her second pregnancy at 26weeks gestation with premature rupture of the membranes and an iliofemoral deep vein thrombosis which developed on enoxaparin 60mg OD. Enoxaparin was increased to 1mg/kg BD and an IVC filter inserted. Despite the filter however she had a pulmonary embolism. The filter was removed after Caesarean section at 31 weeks. Two had sagittal sinus thromboses in the first trimester associated with severe hyperemesis requiring IV fluids. One was our only thromboprophylaxis failure, receiving enoxaparin 40mg OD, she weighed 80Kg. The second presented at 11weeks gestation. She was intolerant of self injecting and so switched to warfarin at 15 weeks until 35 weeks as did one other mother. All mothers had close feto-maternal monitoring with uterine artery Doppler at 24 weeks if possible and then monthly growth scans thereafter. Delivery: Thromboprophylaxis was stopped at labour initiation or 12hrs prior to Caesarean section (3 women) and 50iu/kg of antithrombin concentrate was given. Anticoagulation was restarted 24hrs after delivery. Six weeks enoxaparin post-partum thromboprophylaxis was given or the women converted back to warfarin. Estimated blood loss at delivery was a median of 200ml (range 200–500ml), no transfusions were required. There were no post partum VTEs. Nine births occurred at a median gestation of 38weeks (range 31–41), median birth weight 3045g (range 1420–4120g). One child has West’s syndrome. Conclusion: This is the largest case series on the management of antithrombin deficiency in pregnancy. The combined use of enoxaparin in pregnancy and post partum combined with antithrombin concentrate during labour appears to improve pregnancy outcome and reduce the rate of VTE. Larger studies are required to confirm this finding.

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