231 research outputs found
On the Estimation of Euler Equations in the Presence of a Potential Regime Shift
The concept of a peso problem is formalized in terms of a linear Euler equation and a nonlinear marginal model describing the dynamics of the exogenous driving process. It is shown that, using a threshold autoregressive model as a marginal model, it is possible to produce time-varying peso premia. A Monte Carlo method and a method based on the numerical solution of integral equations are considered as tools for computing conditional future expectations in the marginal model. A Monte Carlo study illustrates the poor performance of the generalized method of moment (GMM) estimator in small and even relatively large samples. The poor performance is particularly acute in the presence of a peso problem but is also serious in the simple linear case.peso problem; Euler equations; GMM; threshold autoregressive models
Mucopolysaccharidosis VI in cats - clarification regarding genetic testing
Debate.
Published online: 02 July 2016.The release of new DNA-based diagnostic tools has increased tremendously in companion animals. Over 70 different DNA variants are now known for the cat, including DNA variants in disease-associated genes and genes causing aesthetically interesting traits. The impact genetic tests have on animal breeding and health management is significant because of the ability to control the breeding of domestic cats, especially breed cats. If used properly, genetic testing can prevent the production of diseased animals, causing the reduction of the frequency of the causal variant in the population, and, potentially, the eventual eradication of the disease. However, testing of some identified DNA variants may be unwarranted and cause undo strife within the cat breeding community and unnecessary reduction of gene pools and availability of breeding animals. Testing for mucopolysaccharidosis Type VI (MPS VI) in cats, specifically the genetic testing of the L476P (c.1427T>C) and the D520N (c.1558G>A) variants in arylsulfataseĀ B (ARSB), has come under scrutiny. No health problems are associated with the D520N (c.1558G>A) variant, however, breeders that obtain positive results for this variant are speculating as to possible correlation with health concerns. Birman cats already have a markedly reduced gene pool and have a high frequency of the MPS VI D520N variant. Further reduction of the gene pool by eliminating cats that are heterozygous or homozygous for only the MPS VI D520N variant could lead to more inbreeding depression effects on the breed population. Herein is debated the genetic testing of the MPS VI D520N variant in cats. Surveys from different laboratories suggest the L476P (c.1427T>C) disease-associated variant should be monitored in the cat breed populations, particularly breeds with Siamese derivations and outcrosses. However, the D520N has no evidence of association with disease in cats and testing is not recommended in the absence of L476P genotyping. Selection against the D520N is not warranted in cat populations. More rigorous guidelines may be required to support the genetic testing of DNA variants in all animal species.Leslie A. Lyons, Robert A. Grahn, Francesca Genova, Michela Beccaglia, John J. Hopwood and Maria Longer
Quantitative Trait Loci affecting the somatic cell score on chromosome 4 and 26 in Italian Holstein cattle
This work aimed to confirm previously reported quantitative trait loci (QTL) affecting the somatic cell score (SCS) in dairy cattle on Bos taurus autosomes (BTA) 4 and 26. A granddaughter design with selective genotyping was implemented that included half-sib families from 12 male lines of Italian Holstein cattle. The animals were genotyped for 5 microsatellite markers each on regions of BTA 4 (average marker spacing 9.42 cM) and BTA 26 (average marker spacing 5.26 cM), previously reported by other authors as carrying QTL for somatic cell count. Quantitative trait loci analyses were performed using interval mapping by regressing sire breeding values for SCS onto genotype probabilities at 1-cM intervals along the 2 chromosome regions. Breeding values for SCS were estimated for the whole population using a test-day repeatability animal model. Results were not significant on a chromosome basis, but a possible QTL was found at BM4505 on BTA 26, confirming this region for further studies of QTL affecting SCS in the Italian Holstein population
Mitochondrial DNA control region variation in Sanfratellano horse and two other Sicilian autochthonous breeds
Mitochondrial D-loop hypervariable region was analysed in 20 Sanfratellano and two other Sicilian autochthonous horse breeds (20 Sicilian Oriental Purebred and 20 Sicilian Indigenous) in order to investigate matrilineal genetic diversity. A total of 20 different haplotypes were identified sequencing a fragment of 397 bp; overall, haplotypes showed 31 polymorphic sites (7.8%). High diversity was detected in Sanfratellano (11 haplotypes) and Sicilian Indigenous (13 haplotypes), whereas only one haplotype was found in Sicilian Oriental Purebred. Sanfratellano sequences were compared with those belonging to the other Sicilian autochthonous horses and 118 sequences selected from the GenBank database in order to calculate the statistics of molecular diversity. Six haplotypes were exclusive of Sanfratellano which shares haplotype C, D, H, and O with the Sicilian Indigenous and haplotype U with the Sicilian Oriental Purebred; not significant differentiation was found between Sanfratellano and Sicilian Indigenous. BLAST search showed Sicilian haplotypes overlap with the database sequences but for three. Phylogenetic analysis did not show monophyletic group for Sanfratellano samples or the other breeds included in this analysis
Correlation between neurotrasmitter levels and anxietyrelated behaviours in cats
Introduction:
The present study aims to evaluate the existing correlations between neurotransmitter levels and
anxiety-related aggressive behaviour.
Materials and methods:
22 adult cats (age > 6months; no pharmacological therapy for behaviour problems) were grouped
according to three different levels of aggressive behaviour: Group 1 (N=11): rare aggressive
attacks, anxiety and aggressive-related behaviour problems reported by the owner; Group 2 (N=4):
frequent aggressive attacks (n attacks > 12/year); Group 3 (N=7): control, no aggressive attacks
reported by the owners. An accurate questionnaire focusing on anxiety and aggressive behaviour
was filled in for every subject and evaluated by a DVM certified Specialist in Veterinary
Behavioural Medicine. Blood samples were collected in EDTA for all the subjects for
neurotransmitters analysis (standard blood processing procedures for HPLC neurotransmitter
analysis were applied). HPLC analysis was carried out for the following neurotransmitters:
Dopamine precursor LDOPA, dopamine DA, noradrenalin NA, adrenalin A, serotonin SE levels in
plasma and platelets; 5-hidrossiindolacetic acid HIAA (serotonin metabolite) and Homovanillic acid
(dopamine metabolite) in platelets. SAS \uae statistic package was applied to data analysis: FREQ,
MEAN and NPAR1WAY procedures were applied; the analysis of variance was carried out using a
Kruscal-Wallis one-way ANOVA.Results:
The results indicate that during the history taking session, the origin of the cat, age at weaning and
human family structure are very helpful in aggressive behaviour evaluation, furthermore
nervousness, shyness and fearfulness related information are closely linked to anxiety related
problems. Higher levels of NA (pg/ml), DA (pg/ml), LDOPA plasma (pg/ml), LDOPA platelet
(pg/ml) were found in Control group (P 640.05). A correlation between neurotransmitter
concentrations and anxiety related behavioural problems has been calculated.
Discussion:
The obtained results suggest, in particular, that the reduction in platelet DA levels could be related
to aggressive behaviour towards animals and human beings. Further analysis is needed to improve
the knowledge of the complex relations between nervous system and behaviour. In addition the
investigation of the genetic basis of behaviour could supply powerful tools in the understanding of
anxiety and aggressiveness in companion animals
The cadaver dog: phenotypical analysis of behaviour
Introduction:
The aim of the present research was to evaluate the behavioural patterns in working cadaver dogs.
Materials and methods:
7 specifically trained dogs (6 Labrador Retrievers; 1 Italian Wolfdog) for human remains search
(HRS) activity were singularly video-recorded during 21 HRS tests in standardied conditions (3
sessions). 3 different odorous samples were used (decomposing teeth, decomposing soft-tissues,
decomposing blood). Frequency(N) and lasting (s) of the scanned behaviours were calculated. Dog
posture and handler behaviour were considered to verify handler dog interaction and response. An
anamnestic-behavioural report was filled for each dog. SAS \uae statistic package was applied to data
analysis: MEAN and NPAR1WAY procedure were applied; the analysis of variance was carried out
using a Kruscal-Wallis one-way ANOVA. Dogs sex and breed, Odorous sample, wind speed and
direction and test order were considered sources of variance.
Results:
The obtained results list an objective sequence of naturally expressed quantitative behaviours during
HRS activity. A strong influence of genetics on trained dogs was recorded, thus breed and sex
showed the most significant effect on dogs HRS behaviours.
Discussion:
Objective studies of breed and sex specific behaviours in HRS, such as the preliminary one we are
presenting, could improve training success and limit training costs and results variability.
Furthermore the constant measurements of environmental and atmospheric variables should become
a common practice before every HRS activity.
According to our results; the handlers could be able to modify through the comprehension of dog\u2019s
behaviour a better way to carry on the HRS
Histocompatibility genes and somatic cell count (SCC) in Italian Holstein Friesian
Geni di istocompatibilit\ue0 e conta delle cellule somatiche (SCC) nella Frisona Italiana \u2013
Lo studio ha considerato l\u2019effetto del Complesso Maggiore di Istocompatibilit\ue0 (MHC) sulla mastite, clinica e subclinica, utilizzando l\u2019Indice Genetico (I.G.) per la conta delle cellule somatiche: SCC (Somatic Cell Count). Su un totale di 302 tori di razza Frisona Italiana, valutati geneticamente per le cellule somatiche, sono stati analizzati il polimorfismo degli antigeni di istocompatibilit\ue0 di classe I (test di microlinfocitotossicit\ue0 locus BoLA-A) e di classe II (PCR/RFLP del locus DRB3 esone 2). L\u2019effetto degli antigeni di istocompatibilit\ue0 sugli indici genetici \ue8 stato valutato con un modello di sostituzione genica
Genetic variability of Akhal-Teke horses bred in Italy
Background. The Akhal-Teke horse (AKH) is native of the modern Turkmenistan area. It was introduced in Italy from 1991 to 2000 mainly as an endurance horse. This paper characterizes the genetic variability of the whole Italian AKH horse population and evaluates their inbreeding level by analyzing microsatellite markers and mitochondrial
D-Loop sequences. Methods. Seventeen microsatellite marker loci were genotyped on 95 DNA samples from almost all the AKH horses bred in Italy in the last 20 years. Standard genetic variability measures (Ho, He, FIS) were compared against the same variables published on other eight AKH populations. In addition, 397 bp of mtDNA D-loop region were sequenced on a sub-group of 22 unrelated AKH out of the 95 sampled ones, and on 11 unrelated Arab horses. The haplotypes identified in the Italian population were aligned to sequences ofAKH(56), Arab (five), Caspian Pony (13), Przewalskii (two) and Barb (15) horses available in GenBank. The Median Joining Network (MJN), Principal Component Analysis (PCA) and Neighbor-joining (NJ) tree were calculated on the
total 126 sequences. Results. Nucleic markers showed a high degree of polymorphism (Ho D 0.642; He D
0.649) and a low inbreeding level (FIS D 0.016) in Italian horses, compared to other AKH populations (ranged from 0.103 AKH from Estonia to 0.114 AKH from Czech Republic). High variability was also recorded in the D-Loop region. 11 haplotypes were identified with haplotype diversity (hd), nucleotide diversity () and average number
of nucleotide differences (k) of 0.938, 0.021 and 6.448, respectively. When all the 126 D-Loop sequences were compared, 51 haplotypes were found, and four were here found only in the Italian AKH horses. The 51 haplotypes were conformed to eight recognized mtDNA haplogroups (A, C, F, G, L, M, P and Q) and confirmed by MJN analysis, Italian horses being assigned to five haplogroups (A, C, G, L and M). Using a PCA approach to the same data, the total haplotypes were grouped into two clusters including A+C+M+P and G+F haplogroups, while L and Q haplogroups remained ungrouped. Finally, the NJ algorithm effectively discretizes only the L haplogroup. All
the above data univocally indicate good genetic variability and accurate management of the Akhal-Teke population in Italy
First genome-wide CNV mapping in FELIS CATUS using next generation sequencing data
Background: Copy Number Variations (CNVs) have becoming very significant variants, representing a major source of genomic variation. CNVs involvement in phenotypic expression and different diseases has been widely demonstrated in humans as well as in many domestic animals. However, genome wide investigation on these structural variations is still missing in Felis catus. The present work is the first CNV mapping from a large data set of Next Generation Sequencing (NGS) data in the domestic cat, performed within the 99 Lives Consortium. Results: Reads have been mapped on the reference assembly_6.2 by Maverix Biomics. CNV detection with cn.MOPS and CNVnator detected 592 CNVs. These CNVs were used to obtain 154 CNV Regions (CNVRs) with BedTools, including 62 singletons. CNVRs covered 0.26% of the total cat genome with 129 losses, 19 gains and 6 complexes. Cluster Analysis and Principal Component Analysis of the detected CNVRs showed that breeds tend to cluster together as well as cats sharing the same geographical origins. The 46 genes identified within the CNVRs were annotated. Conclusion: This study has improved the genomic characterization of 14 cat breeds and has provided CNVs information that can be used for studies of traits in cats. It can be considered a sound starting point for genomic CNVs identification in this species
- ā¦