A revised method for estimating population densities of common wombats (Vombatus ursinus)

2012 ◽  
Vol 34 (2) ◽  
pp. 170
Author(s):  
John McIlroy ◽  
John Collins ◽  
Philip Borchard
Keyword(s):  
Population Density ◽  
Regression Equations ◽  
Population Densities ◽  
Common Wombat ◽  
The Common ◽  
The Mean

Estimation of the population density of the common wombat (Vombatus ursinus) has used regression equations based on the mean number of burrows used per 24 h over five successive 24-h periods. While adequate, the method has several deficiencies and required 6 successive days of fieldwork to carry out. We describe a revised method based on considerably more data. It provides more precise estimates, can be used for greater numbers of used burrows and can be carried out over a much shorter period.

Population dynamics and production of a brine shrimp, Parartemia zietziana Sayce (Crustacea : Anostraca), in two salt lakes in westren Victoria, Australia

1977 ◽  
Vol 28 (4) ◽  
pp. 417 ◽  
Author(s):  
R Marchant ◽  
WD Williams
Keyword(s):  
Population Dynamics ◽  
Population Density ◽  
Temperature Stress ◽  
Brine Shrimp ◽  
Dry Weight ◽  
Salt Lakes ◽  
Confidence Limits ◽  
Length Frequency ◽  
Population Densities ◽  
The Mean

Quantitative samples of P. zietziana were taken monthly for two years from Pink Lake and Lake Cundare. Shrimps were usually contagiously distributed. To reduce error, samples were stratified resulting in confidence limits of 40-50% for the mean population density. Despite this variability, stable trends emerged, and variation was not so great as to mask significant differences. Length-frequency analyses distinguished cohorts; a regression was established between length and dry weight, enabling growth to be estimated from samples. By combining growth with population densities in Allen curves, production was computed. In Pink Lake and Lake Cundare mean pro- duction was 11.3 and 1.0 g dry weight m-2 year-1 respectively. Generally there were two or three generations per year, but time and extent of recruitment were not predictable. Each generation suffered continuous mortality, the death of young shrimps accounting for most of the production. This mortality remains unexplained; there are no significant predators and salinity and temperature stress would occur only during summer.

The Kidney Structure of the Common Wombat (Vombatus-Ursinus) and the Hairy-Nosed Wombat (Lasiorhinus-Latifrons)

1995 ◽  
Vol 43 (2) ◽  
pp. 181 ◽  
Author(s):  
BM Mcallan ◽  
JR Roberts ◽  
PS Barboza
Keyword(s):  
Plasma Sodium ◽  
Kidney Weight ◽  
Kidney Size ◽  
Kidney Structure ◽  
Collecting Ducts ◽  
Common Wombat ◽  
The Common ◽  
The Mean ◽  
Distal Tubules ◽  
Urinary Concentrating Ability

The common wombat (Vombatus ursinus) lives in a mesic habitat whereas the hairy-nosed wombat (Lasiorhinus latifrons) inhabits a xeric habitat. The kidney structure of these two wombats was studied and it was found that kidney size, kidney weight, and kidney weight as a percentage of body weight, were larger in V. ursinus. However, relative medullary thickness, percentage medullary volume, and medullary thickness as a percentage of total thickness, were significantly greater in L. latifrons, suggesting that L. latifrons has a greater capacity to conserve water than does V. ursinus. The number of glomeruli and mean glomerular area were the same in both species whereas the mean diameter of the proximal and distal tubules was larger in V. ursinus. There were more proximal tubules per square millimetre in L. latifrons. The larger number of collecting ducts per square millimetre in the medullary region in L. latifrons indicates that the nephrons join the collecting ducts deep in the medulla, a feature that has been associated with increased urinary concentrating ability. Urinary pH was significantly lower, and urinary ammonia, creatinine and sodium levels were higher, in L. latifrons, as were plasma sodium and chloride levels. These data suggest that L. latifrons has a greater capacity to conserve water.

Estimating Population Densities of Root Lesion Nematodes, Pratylenchus spp., from Soil Samples Using Dual Active and Passive Assays

2012 ◽  
Vol 13 (1) ◽  
pp. 4 ◽  
Author(s):  
Ann E. MacGuidwin ◽  
Breann E. Bender
Keyword(s):  
Population Density ◽  
Soil Samples ◽  
Scaling Factor ◽  
The Other ◽  
Testing Methods ◽  
Population Densities ◽  
Lesion Nematodes ◽  
The Mean ◽  
Time Of Year ◽  
Root Lesion Nematodes

Root lesion nematodes are versatile parasites that move freely between root and soil habitats. Most laboratories conduct separate assays for soil or root tissue, using time-of-year as the selecting factor. We used a dual assay that simultaneously extracts nematodes from soil and root fragments in soil samples to identify the value of soil versus root tests using 920 research samples collected 1 April to 15 May, and 853 clinic samples collected year round. Nematodes were recovered from both soil and root fragments regardless of the time of year or origin of the sample. When the data were summarized by cohort, the mean percentage of nematodes recovered from root fragments was 65% for the research samples, 59% for clinic samples submitted 1 March to 15 June, 56% for clinic samples submitted 16 June to 31 July, and 49% for clinic samples submitted after 1 August. Both the incidence and population density of root lesion nematodes was underestimated if only the soil or only the root fraction was considered, indicating the need for testing methods that consider both habitats. The variability among samples for the distribution of nematodes between root and soil habitats was high, negating the option of running one assay and using a constant scaling factor to account for the other. Accepted for publication 30 October 2012. Published 20 November 2012.

scholarly journals Culture of rotifer Brachionus angularis Hauer feeding with dried Chlorella

1970 ◽  
Vol 26 ◽  
pp. 73-76 ◽  
Author(s):  
Shabnam Mostary ◽  
M Shahidur Rahman ◽  
M Amzad Hossain
Keyword(s):  
Population Density ◽  
Dissolved Oxygen ◽  
Air Temperature ◽  
Physicochemical Parameters ◽  
Culture Medium ◽  
Yeast Culture ◽  
Population Densities ◽  
The Mean ◽  
Brachionus Angularis ◽  
Better Than

A study was carried out to know the performance of powdered dried Chlorella for culture of rotifer Brachionus angularis. B. angularis was fed with powdered dried Chlorella in treatment 1, live or fresh cultured Chlorella in treatment 2 and baker’s yeast in treatment 3. The rage of physicochemical parameters during culture of rotifer such as water temperature, air temperature, pH and dissolved oxygen were within the suitable ranges for B. angularis culture and more or less similar in all the treatments. The highest population densities of B. angularis recorded in treatment 1, treatment 2 and treatment 3 were 50, 60 and 30 ind/ml, respectively. The mean population densities were 30.1±12.2, 37.4±14.6 and 21.1±6.1 ind./ml in treatment 1, treatment 2 and treatment 3, respectively. The results revealed that the powdered dried Chlorella had significant effect on the population density of B. angularis and was better than that of baker’s yeast. So, when live Chlorella will not be available, powdered dried Chlorella can be successfully used as feed for B. angularis culture. Keywords: Rotifer, Chlorella, yeast, culture medium Univ. j. zool. Rajshahi Univ. Vol. 26, 2007. pp. 73-76

Studies on the spatial heterogeneity of shallow water benthos with particular reference to the Chironomidae

1971 ◽  
Vol 49 (7) ◽  
pp. 1013-1019 ◽  
Author(s):  
C. G. Paterson ◽  
C. H. Fernando
Keyword(s):  
Opposite Effect ◽  
Common Species ◽  
Distributional Pattern ◽  
Population Densities ◽  
Benthic Species ◽  
Experimental Examination ◽  
The Common ◽  
The Mean ◽  
Total Fauna ◽  
Behavioral Mechanisms

The examination of numbers of 6-in. Ekman grab samples from areas of 2 m2 or less in a variety of shallow lentic habitats revealed heterogeneity in the spatial distribution of most species of macrobenthos in each habitat. Chironomus abortivus Malloch, Glyptotendipes barbipes (Staeger), Procladius freemani Sublette, and the Oligochaeta were invariably aggregated when their population densities were adequate to determine a distributional pattern. The Chironomidae, considered as a group, also displayed an aggregated distribution in all habitats. Other benthic species had distributional patterns that varied from random to highly aggregated in the different habitats. No evidence was found that any species are normally randomly distributed. Analyses of mean crowding of the common species in each habitat suggest that the species often respond independently to microenvironmental variations. The factors which produce well-defined aggregations of one species may be neutral, or they may have the opposite effect on the distribution of other species. Experimental examination of the possible occurrence of behavioral mechanisms of aggregation in the two chironomids, Chironomus attenuatus Walker and Glyptotendipes barbipes, revealed that they lend to aggregate at low population densities (≈ 1/10 cm2) but are randomly distributed in a uniform environment when present in higher densities. Because of the aggregated nature of most benthic species four 6-in. Ekman grab samples were usually required to obtain a population estimate of the total fauna, total chironomid fauna, and the dominant species within ± 30% of the mean obtained with a larger number of samples.

Comparison of Heffner Criteria and Light Criteria in Differentiating Exudative and Transudative Pleural Effusion

2020 ◽  
Vol 22 (3) ◽  
pp. 141-145
Author(s):  
Krishna Chandra Devkota ◽  
S Hamal ◽  
PP Panta
Keyword(s):  
Pleural Effusion ◽  
Cross Sectional Study ◽  
Pleural Space ◽  
Sectional Study ◽  
Inclusion Criteria ◽  
Cross Sectional ◽  
Medical College ◽  
The Common ◽  
The Mean ◽  
Exudative Pleural Effusion

Pleural effusion is present when there is >15ml of fluid is accumulated in the pleural space. It can be divided into two types; exudative and transudative pleural effusion. Tuberculosis and parapneumonic effusion are the common cause of exudative pleural effusion whereas heart failure accounts for most of the cases of transudative pleural effusion. This study was a hospital based cross sectional study performed at Nepal Medical College during the period of January 2016-December 2016. A total of 50 patients who fulfilled the inclusion criteria were enrolled. Pleural effusion was confirmed by clinical examination and radiology. After confirmation of pleural effusion, pleural fluid was aspirated and was analysed for protein, LDH, cholesterol. The Heffner criteria was compared with Light criteria to classify exudative or transudative pleural effusion. Among 50 patients, 30 were male and 20 were female. The mean age of patient was 45.4±21.85 years. The sensitivity and specificity of using Light criteria to detect the two type of pleural effusion was 100% and 90.9%, whereas using Heffner criteria was 94.87%, 100% respectively(P<0.01). There are variety of causes for development of pleural effusion and no one criteria is definite to differentiate between exudative or transudative effusion. In this study Light criteria was more sensitive whereas Heffner criteria was more specific to classify exudative pleural effusion. Hence a combination of criteria might be useful in case where there is difficulty to identify the cause of pleural effusion.

Of Reformed Versifying

2018 ◽  
Author(s):  
Neil Rhodes
Keyword(s):  
Sixteenth Century ◽  
Faerie Queene ◽  
Classical Literature ◽  
Native Form ◽  
Christian Doctrine ◽  
English Verse ◽  
The Common ◽  
The Mean ◽  
The Faerie Queene ◽  
Stylistic Ideal

This chapter examines how the development of English poetry in the second half of the sixteenth century is characterized by the search for an appropriate style. In this context, ‘reformed versifying’ may be understood as a reconciliation of high and low in which the common is reconfigured as a stylistic ideal of the mean. That development can be traced in debates about prosody where an alternative sense of ‘reformed versifying’ as adapting classical metres to English verse is rejected in favour of native form. At the same time Sidney recuperates poetry by reforming it as an agent of virtue. Reformation and Renaissance finally come together in Spenser, who realizes Erasmus’ aim of harmonizing the values of classical literature with Christian doctrine, and reconciles the foreign and the ‘homewrought’. The Faerie Queene of 1590 represents the triumph of the mean in both style and, through its celebration of marriage, in substance.

scholarly journals Genetic gain in the breeding program of common beans at IAC from 1989 to 2007

2010 ◽  
Vol 10 (4) ◽  
pp. 329-336 ◽  
Author(s):  
Alisson Fernando Chiorato ◽  
Sérgio Augusto Morais Carbonell ◽  
Roland Vencovsky ◽  
Nelson da Silva Fonseca Júnior ◽  
José Baldin Pinheiro
Keyword(s):  
Grain Yield ◽  
Common Bean ◽  
Genetic Gain ◽  
Grain Quality ◽  
The State ◽  
Breeding Program ◽  
Common Beans ◽  
The Common ◽  
The Mean ◽  
Second Period

The goal of the present work was to evaluate the genetic gain obtained in grain yield for the common bean genotypes from 1989 until 2007, at the Instituto Agronômico de Campinas, in the state of São Paulo. Genetic gain has been separated into two research periods; the first, from 1989 to 1996, and the second, from 1997 to 2007. In the first period, a genetic gain of 1.07 % per year was obtained, whereas for the second period, the gain was zero. However, the mean yield of the evaluated lines was approximately 1000 kg ha-1 superior to the figures obtained in the first period. The main cause for the absence of genetic gain in the second period is that the focus of the breeding program was changed to grain quality. The individualized analysis of the genotypes with carioca grains in the second period indicated the lack of genetic gain during the investigated period.

scholarly journals Population density of helminths in ducks: effects of host’s age, sex, breed and season

1970 ◽  
Vol 6 (1) ◽  
pp. 45-51 ◽  
Author(s):  
T Farjana ◽  
KR Islam ◽  
MMH Mondal
Keyword(s):  
Population Density ◽  
Key Words ◽  
Parasitic Infection ◽  
Winter Season ◽  
Helminth Parasites ◽  
Domestic Ducks ◽  
The Mean

 A study was conducted to investigate the population density of helminth parasites in domestic ducks (Anas boschas domesticus) in relation to host's age, sex, breed and seasons of the year from March 2002 to May 2003. A total of 300 ducks were collected from different villages of Netrokona and Mymensingh districts of Bangladesh and autopsied to collect the parasites and counted to determine the population density of parasites. Off 300 ducks examined, 290 (96.66%) were infected with 17 species of helminth parasites in which 11 species were trematodes, 4 were cestodes and 2 nematodes. Among the parasites, density of cestodes was the highest (33.15±5.26), followed by trematodes (5.98±1.32); and nematodes (2.95±0.68). Mean density of parasites increased with the increase of age (young: 21.23±1.09, adult: 26.18±2.14 and old: 27.87±2.98) while the mean density of most of the helminth parasites was higher in female ducks (31.35±4.72) than in males (27.52±3.32). Indigenous ducks (33.72±3.61) were infected with the highest load of helminths than Khaki Campbell breed (29.61±4.32) of ducks. Mean density of most trematodes (5.42±0.80) were highest in winter season whereas mean density of all cestodes (48.43±4.85) and nematodes (4.13±1.76) were highest in summer.  The present study suggests that age, sex, breed of ducks and seasons of the year influence the parasitic infection to a greater extend. Key words: Population density, helminths, duck, Bangladesh DOI = 10.3329/bjvm.v6i1.1338 Bangl. J. Vet. Med. (2008). 6 (1): 45-51

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