Morphometric similarity of Mallards and American Black Ducks

1994 ◽  
Vol 72 (12) ◽  
pp. 2248-2251 ◽  
Author(s):  
Alan R. Hanson ◽  
C. Davison Ankney
Keyword(s):  
New Brunswick ◽  
Discriminant Function ◽  
Lake Erie ◽  
Correct Classification ◽  
Tarsus Length ◽  
Eastern Canada ◽  
Morphometric Analyses ◽  
Wing Chord ◽  
American Black ◽  
Discriminant Function Analyses

Morphometric data were collected from 347 American Black Ducks (Anas rubripes), and 1466 Mallards (Anas platyrhynchos) taken by hunters in the Lake St. Clair and Lake Erie regions of southwestern Ontario during autumn 1986 and from 511 American Black Ducks shot throughout the province of New Brunswick during the 1988 and 1989 hunting seasons. Discriminant function analyses based on eight external morphometric variables (wing chord, tarsus length, middle toe length, hind toe length, culmen, head length, naris width, and bill width) did not accurately distinguish Black Ducks from Mallards. Discriminant function analyses produced correct classification rates that, averaged over the four age–sex classes, were 61% for Mallards and 71% for Black Ducks. The highest classification rates were from the discriminant function analyses of Ontario Black Ducks and New Brunswick Black Ducks that, averaged over the four age–sex classes, were 74% for Ontario Black Ducks and 80% for New Brunswick Black Ducks. Although our morphometric analyses did not incorporate all morphometric characteristics of Black Ducks and Mallards, they do show that Black Ducks and Mallards collected in eastern Canada are morphometrically very similar.

scholarly journals A Critical Evaluation of Kenyon's Shag (Phalacrocorax [Stictocarbo] Kenyoni)

The Auk ◽  
2000 ◽  
Vol 117 (2) ◽  
pp. 308-320 ◽  
Author(s):  
Sievert Rohwer ◽  
Christopher E. Filardi ◽  
Kimberly S. Bostwick ◽  
A. Townsend Peterson
Keyword(s):  
Discriminant Function ◽  
Principal Components ◽  
North Pacific ◽  
Critical Evaluation ◽  
Aleutian Islands ◽  
Type Specimens ◽  
Morphometric Analyses ◽  
Qualitative Characters ◽  
Morphometric Evaluation ◽  
Discriminant Function Analyses

Abstract We examine the validity of Phalacrocorax [Stictocarbo] kenyoni, which was described by Siegel-Causey (1991) from the Aleutian Islands using midden remains and existing skeletal specimens. We emphasize a morphometric evaluation of the taxon using 224 skeletal specimens of North Pacific cormorants, but we also evaluate the qualitative characters originally used to characterize P. kenyoni. Principal components and discriminant function analyses of 14 skeletal characters failed to support the validity of the species. Similarly, all seven of the character states that Seigel-Causey described as unique to P. kenyoni also were found in P. pelagicus and P. urile. Thus, the three type specimens of P. kenyoni appear to be P. pelagicus. Although we could not confirm the validity of P. kenyoni, our morphometric analyses revealed that P. pelagicus individuals from the central Aleutians are smaller than those from surrounding populations.

Evidence for genetic hybridization between Ixodes scapularis and Ixodes cookei

2017 ◽  
Vol 95 (8) ◽  
pp. 527-537 ◽  
Author(s):  
James W. Patterson ◽  
Anna M. Duncan ◽  
Kelsey C. McIntyre ◽  
Vett K. Lloyd
Keyword(s):  
Mitochondrial Dna ◽  
Genetic Analysis ◽  
New Brunswick ◽  
Nuclear Dna ◽  
Ixodes Scapularis ◽  
Companion Animals ◽  
Genetic Introgression ◽  
Eastern Canada ◽  
As Species ◽  
Intermediate Traits

Ixodes scapularis Say, 1821 (the black-legged tick) is becoming established in Canada. The northwards expansion of I. scapularis leads to contact between I. scapularis and Ixodes cookei Packard, 1869, a well-established tick species in Eastern Canada. Examination of I. cookei and I. scapularis collected from New Brunswick revealed ticks with ambiguous morphologies, with either a mixture or intermediate traits typical of I. scapularis and I. cookei, including in characteristics typically used as species identifiers. Genetic analysis to determine if these ticks represent hybrids revealed that four had I. cookei derived mitochondrial DNA but I. scapularis nuclear DNA. In one case, the nuclear sequence showed evidence of heterozygosity for I. scapularis and I. cookei sequences, whereas in the others, the nuclear DNA appeared to be entirely derived from I. scapularis. These data strongly suggest genetic hybridization between these two species. Ixodes cookei and hybrid ticks were readily collected from humans and companion animals and specimens infected with Borrelia burgdorferi Johnson et al., 1984, the causative agent of Lyme disease, were identified. These findings raise the issue of genetic introgression of I. scapularis genes into I. cookei and warrant reassessment of the capacity of I. cookei and I. cookei × I. scapularis hybrids to vector Borrelia infection.

scholarly journals A revision of bird skin preparation aimed at improving the scientific value of ornithological collections

2021 ◽  
pp. 175815592098715
Author(s):  
José Carrillo-Ortiz ◽  
Santi Guallar ◽  
Jessica Martínez-Vargas ◽  
Javier Quesada
Keyword(s):  
The Body ◽  
Biological Knowledge ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Tarsus Length ◽  
Skin Preparation ◽  
Primary Feather ◽  
Preparation Methods ◽  
Wing Chord ◽  
Scientific Value

The methods used to preserve bird skins in museums have a potentially crucial impact on the feasibility and use of these specimens as a source of biological knowledge, although this subject is rarely broached. Study skins of birds are usually prepared with folded wings and straight legs to facilitate storage in the collection; yet, this method can hamper the measurement and examination of certain important features such as wing-feather moult. To make consultation easier for ornithologists, alternative preparation methods such as the splitting of wings and tarsi from the rest of the animal have been proposed by curators. Our aim was to study whether or not preparing bird specimens with spread limbs makes consultation simpler. First, we used two different methods to prepare two specimens each of two common European passerine species: (1) ‘traditional’ (folded wings and straight tarsi) and (2) ‘spread’ (limbs spread on one side of the body). Then, we asked 22 experienced ornithologists to identify moult limits and take three biometric measurements (wing chord, length of the third primary feather and tarsus length) from all four specimens. Subsequently, we asked which preparation method they preferred for obtaining data. The ‘spread’ preparation was preferred for moult, third primary feather length and tarsus length, whilst the ‘traditional’ preparation was preferred for wing chord. Data obtained from the folded and spread preparations were very highly repeatable within each method but only moderately to highly repeatable between methods. One of the handicaps with the ‘spread’ preparation is the increase in storage space required, a factor that should be taken into account before it is employed. Nevertheless, this specimen preparation technique can greatly facilitate consultation and therefore improve the scientific value of ornithological collections.

Studies of Predators of the Balsam Woolly Aphid, Adelges piceae (Ratz.) (Homoptera: Adelgidae): XI. Cremifania nigrocellulata Cz. (Diptera: Chamaemyiidae), An Introduced Predator in Eastern Canada

1962 ◽  
Vol 94 (11) ◽  
pp. 1171-1175 ◽  
Author(s):  
R. C. Clark ◽  
N. R. Brown
Keyword(s):  
Biological Control ◽  
New Brunswick ◽  
Eastern Canada ◽  
Introduced Predator ◽  
Woolly Aphid ◽  
Commonwealth Institute ◽  
Adelges Piceae ◽  
Research Institute

Cremifania nigrocellulata Cz. is one of the complex of predators that attacks A. piceae (Ratz.) in Europe. After studies on its morphology, biology, and distribution were made by Delucchi and Pschorn-Walcher (1954), C. nigrocellulata was reared in Europe by the Commonwealth Institute of Biological Control and introduced into New Brunswick via the Entomology Research Institute for Biological Control, Belleville, Ontario.

CLAY ILLUVIATION IN SOME ORTHIC PODZOLS OF EASTERN CANADA

1965 ◽  
Vol 45 (2) ◽  
pp. 127-138 ◽  
Author(s):  
J. E. Brydon
Keyword(s):  
Organic Matter ◽  
New Brunswick ◽  
Iron Oxides ◽  
Clay Content ◽  
Granular Structure ◽  
Charge Component ◽  
Eastern Canada ◽  
Free Iron ◽  
Fine Clay ◽  
Ph Dependent

The Arago, Barney, and Holmesville soils, Podzols from Quebec, Nova Scotia, and New Brunswick, respectively, each had friable Bfh horizons with moderate granular structure, and with organic matter and free Fe2O3 contents greater than the Ae and C horizons. The Arago and Holmesville had thin Bhft horizons containing over 10% organic matter and 5% free iron oxides. The C horizons of these two soils had some features characteristic of fragipans.The B horizons of the three soils had a high "pH-dependent charge component" in the C.E.C. values. The "permanent charge component" was similar throughout the Arago profile except for the Bhft horizon where clay accumulation had occurred.Translocation of clay from the Ae to the upper B horizons was indicated by the twofold increase in clay content and the relative enrichment of fine clay in the B horizons. Removal of free iron affected the clay contents differently in the different: horizons but the maximum clay content in the upper B horizons remained. The definitions of Orthic Podzols, Textural Podzols, and t horizons should be re-examined.

Validity and Clinical Scale Comparisons between the MMPI and MMPI-2 with Psychiatric Inpatients

1992 ◽  
Vol 70 (1) ◽  
pp. 323-332 ◽  
Author(s):  
Dudley David Blake ◽  
Phillip M. Kleespies ◽  
Walter E. Penk ◽  
Suellen S. Walsh ◽  
DeAnna L. Mori ◽  
...  
Keyword(s):  
Discriminant Function ◽  
Relative Stability ◽  
Patient Population ◽  
Psychiatric Patients ◽  
Special Populations ◽  
Clinical Scale ◽  
Acute Psychiatry ◽  
Highly Correlated ◽  
Discriminant Function Analyses

This study was designed to investigate the comparability of the original MMPI (1950) and the MMPI-2 (1989) with a psychiatric patient population. 34 male and 3 female patients, shortly after admission to one of two acute psychiatry units, completed the old and revised versions of the MMPI. Paired t tests indicated but scant differences for raw scores, while many more differences were found among T scores for validity, clinical, and supplemental scales. Analyses, however, showed all scales on the two forms to be highly correlated. Analysis of the high-point and two-point codes across the two administrations also showed relative stability, although the proportion of Scales 2 (Depression) and 8 (Schizophrenia) decreased, while those for Scales 6 (Paranoia) and 7 (Psychasthenia) increased markedly in the MMPI-2 protocols. Examination of each version's discriminability among mood- and thought-disordered subsamples suggested that the MMPI provides slightly better delineation between diagnostic classes. Discriminant function analyses showed that there were essentially no differences between the two forms in the accurate classification of clinical and nonclinical groups. The findings reported here provide support for the MMPI-2; despite modification, the newer form retains the advantages of the original MMPI. Differences found here may be unique to psychiatric patients and their patterns of MMPI/MMPI-2 equivalence and may not generalize to other special populations.

scholarly journals New records and AMS radiocarbon dates on Quaternary Walrus ( Odobenus Rosmarus ) from New Brunswick

2002 ◽  
Vol 51 (1) ◽  
pp. 107-111 ◽  
Author(s):  
Randall F. Miller
Keyword(s):  
New Brunswick ◽  
New Records ◽  
Temporal Distribution ◽  
Late Glacial ◽  
Bay Of Fundy ◽  
Eastern Canada ◽  
Radiocarbon Dates ◽  
Odobenus Rosmarus ◽  
Sand And Gravel ◽  
Past Summer

Abstract Walrus fossils are occasionally recovered during scallop dragging in the Bay of Fundy and from sand and gravel deposits along the coastline of New Brunswick in eastern Canada. Six new fossils and four new AMS radiocarbon dates significantly increase the information concerning late-glacial to postglacial walrus in New Brunswick. Dates range from about 12 800 BP to 2 900 BP, almost half falling between 9 000 and 10 000 BP. Temporal distribution of walrus, compared to estimates of past summer sea surface temperature, suggest that in the Bay of Fundy walrus occurred in waters ranging from 12 to 15° C.

scholarly journals Truss network based morphometric and meristic variations among south-western populations of Macrognathus aculeatus in Bangladesh

2021 ◽  
Vol 42 (3(SI)) ◽  
pp. 887-894
Author(s):  
M. Sarower-E-Mahfuj ◽  
◽  
S.K. Das ◽  
K.N. Azad ◽  
A.K. Paul ◽  
...  
Keyword(s):  
Analysis Of Variance ◽  
Discriminant Function ◽  
Network System ◽  
Meristic Characters ◽  
Morphometric Characters ◽  
Baseline Information ◽  
Macrognathus Aculeatus ◽  
Post Hoc ◽  
Separation Results ◽  
Discriminant Function Analyses

Aim: Landmark-based truss network system was applied to examine the morphometric and meristic differences among four different populaces of Macrognathus aculeatus namely; Dhakuriabeel, Jashore (DBJ); Arial Kha River, Madaripur (AKRM); Nabaganga River, Jhenaidah (NRJ); Kopotakkha River, Jashore (KRJ) in Bangladesh. Methodology: Completely 80 samples of M. aculeatus were collected (20 individuals from each population) for this study. Six meristic characters, 6 morphometric characters and 15 truss-based morphometric characters were measured for one-way analysis of variance (ANOVA) and Tukey-HSD post hoc test. Discriminant function analyses were also performed by using morphometric and truss-based morphometric characters to detect potential characters responsible for population separation. Results: Completely 80 samples of M. aculeatus were collected (20 individuals from each population) for this study. Six meristic characters, 6 morphometric characters and 15 truss-based morphometric characters were measured for one-way analysis of variance (ANOVA) and Tukey-HSD post hoc test. Discriminant function analyses were also performed by using morphometric and truss-based morphometric characters to detect potential characters responsible for population separation. Interpretation: The baseline information derived from the present study would be useful for appropriate conservation of M. aculeatus populations as well as for the researchers for further investigation.

Obsidian Blades from La Blanca, a Changing Lithic Industry on the South Coast of Guatemala

1991 ◽  
Vol 2 (4) ◽  
pp. 371-383 ◽  
Author(s):  
C. Roger Nance ◽  
Katharine A. Kirk
Keyword(s):  
Low Power ◽  
Discriminant Function ◽  
Linear Discriminant Function ◽  
South Coast ◽  
Linear Discriminant ◽  
Bipolar Technology ◽  
Lithic Industry ◽  
Edge Wear ◽  
Middle Preclassic ◽  
Discriminant Function Analyses

In a study of Middle Preclassic (Conchas phase) ceramics from the site of La Blanca, Love (1989) derived a sequence of four subphases. Here, the focus is on 431 prismatic obsidian blades excavated from the same deposits in order to discern if patterns of change can be discovered in this lithic industry. For each blade, recorded attributes describe blade dimensions and edge wear, as observed through low-power microscopy. Chronological controls were set by ceramic associations. Through the sequence, blades became smaller and more fragmentary, due, we hypothesized, to an increasing scarcity of obsidian. As predicted from these trends, we found that wear patterns became more pronounced through time, and use of a bipolar technology became increasingly important for removing (rejuvenating) worn lateral edges. A definite obsidian-blade sequence emerged, which was investigated through linear discriminant-function analyses.

scholarly journals Detection of Malignancy Associated Changes in Cervical Cell Nuclei Using Feed-Forward Neural Networks

1997 ◽  
Vol 14 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Roger A. Kemp ◽  
Calum MacAulay ◽  
David Garner ◽  
Branko Palcic
Keyword(s):  
Neural Networks ◽  
Discriminant Function ◽  
Severe Dysplasia ◽  
Correct Classification ◽  
Correct Classification Rate ◽  
Classification Rate ◽  
Normal Cells ◽  
Feed Forward ◽  
Linear Discriminant ◽  
Feed Forward Neural Networks

Normal cells in the presence of a precancerous lesion undergo subtle changes of their DNA distribution when observed by visible microscopy. These changes have been termed Malignancy Associated Changes (MACs). Using statistical models such as neural networks and discriminant functions it is possible to design classifiers that can separate these objects from truly normal cells. The correct classification rate using feed‐forward neural networks is compared to linear discriminant analysis when applied to detecting MACs. Classifiers were designed using 53 nuclear features calculated from images for each of 25,360 normal appearing cells taken from 344 slides diagnosed as normal or containing severe dysplasia. A linear discriminant function achieved a correct classification rate of 61.6% on the test data while neural networks scored as high as 72.5% on a cell‐by‐cell basis. The cell classifiers were applied to a library of 93,494 cells from 395 slides, and the results were jackknifed using a single slide feature. The discriminant function achieved a correct classification rate of 67.6% while the neural networks managed as high as 76.2%.

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