ABSTRACT
An approximately 3,000 finishing swine operation in the United States experienced an outbreak of an atypical neurologic disease in 11-weeks-old pigs with an overall morbidity of 20% and case fatality rate of 30%. The clinical onset and progression of signs in affected pigs varied but included inappetence, compromised ambulation, ataxia, incoordination, mental dullness, paresis, paralysis and decreased response to environmental stimuli. Tissues from affected pigs were submitted for diagnostic investigation. Histopathologic examination of the cerebrum, cerebellum and spinal cord revealed severe lymphoplasmacytic and necrotizing polioencephalomyelitis with multifocal areas of gliosis and neuron satellitosis, suggestive of a neurotropic viral infection. Bacterial pathogens were not isolated by culture of neurologic tissue from affected pigs. Samples tested by polymerase chain reaction (PCR) were negative for pseudorabies virus and atypical porcine pestivirus. Immunohistochemistry for porcine reproductive and respiratory syndrome virus, porcine circovirus and Listeria was negative. Porcine sapelovirus (PSV) was identified in spinal cord by a nested PCR used to detect porcine enterovirus, porcine teschovirus and PSV. Next-generation sequencing of brainstem and spinal cord samples identified PSV and the absence of other or novel pathogens. In addition, Sapelovirus A mRNA was detected in neurons and nerve roots of the spinal cord by in situ hybridization. The PSV is genetically novel with an overall 94% amino acid identity and 86% nucleotide identity to a recently reported sapelovirus from Korea. This is the first case report in the United States associating sapelovirus with severe polioencephalomyelitis in pigs.
Subject(s)
Circoviridae Infections/epidemiology , Encephalomyelitis, Enzootic Porcine/virology , Enterovirus Infections/veterinary , Picornaviridae Infections/veterinary , Picornaviridae/isolation & purification , Swine Diseases/virology , Animals , Disease Outbreaks , Enterovirus Infections/virology , Enteroviruses, Porcine/isolation & purification , Immunohistochemistry , In Situ Hybridization , Nerve Tissue/virology , Picornaviridae/genetics , Polymerase Chain Reaction , RNA Viruses , Swine , Swine Diseases/epidemiology , United States/epidemiologyABSTRACT
Many issues in DNA barcoding need to be solved before it can reach its goal to become a general database for species identification. While species delimitations are more or less well established in several taxa, there are still many groups where this is not the case. Without the proper taxonomic background/knowledge and corroboration with other kinds of data, the DNA barcoding approach may fail to identify species accurately. The classification and taxonomy of phylum Nemertea (nemerteans, ribbon worms) are traditionally based on morphology, but are not corroborated by an increasing amount of genetic data when it comes to classification either into species or into higher taxa. The taxonomy of the phylum needs to be improved before the full potential of DNA barcoding can be utilized to make sure that valid Linnean names accompany the barcode sequences. We illustrate the problematic situation in the phylum Nemertea by a case study from the genus Cerebratulus.
ABSTRACT
Industry-level impacts of highly contagious foreign animal diseases can be extensive and disruptive. These impacts are the sum of disease effects on the separate economic units that comprise the input supply, production, processing and marketing system of that industry. These industry-level effects would not include government costs or costs associated with disrupted travel or tourism or general economic activity. Direct impacts are those that are related to production and result in direct economic consequences for animal protein producers. Indirect impacts are consequences that include loss of trade, market and consumer confidence, among others. While it is prudent for governments to identify the costs of effective surveillance and prevention, these costs are often very small compared to the total cost of response and recovery associated with a disease outbreak. It is important that the effectiveness of those prevention programmes not be compromised because of other short-term priorities perceived to be more urgent.
ABSTRACT
Few issues in swine production are as complex as floor space allowances. One method for pork producers to calculate floor space allowance (A) is to convert BW into a 2-dimensional concept yielding an expression of A = k * BW(0.667). Data on ADG, ADFI, and G:F were obtained from published peer-reviewed studies. Five data sets were created: A = grower-finisher pigs, fully slatted floors, and consistent group size; B = grower-finisher pigs and fully slatted floors (group size did not need to be consistent); C = grower-finisher pigs, partially slatted floors, and consistent group size; D = grower-finisher pigs, partially slatted floors (group size did not need to be consistent); and E = nursery pigs, fully slatted or woven wire floors (group size did not need to be consistent). Each data set was analyzed using a broken-line analysis and a linear regression. For the broken-line analyses, the critical k value, below which a decrease in ADG occurred, varied from 0.0317 to 0.0348. In all cases the effect of space allowance on ADG was significant (P < 0.05). Using the linear analyses based on data with k values of < 0.030, the critical k values for the 4 grower-finisher data sets did not differ from those obtained using the broken-line analysis (0.0358 vs. 0.0336, respectively; P > 0.10); however, none of the linear regressions explained a significant proportion of the variation in ADG. The slopes for the nonplateau portion of the broken-line analyses based on percent values varied among data sets. For every 0.001 decrease in k (approximately 3% of the critical k value), ADG decreased by 0.56 to 1.41%, with an average value of 0.98% for the 5%-based analyses. The use of an allometric approach to express space allowance and broken-line analysis to establish space requirements seem to be useful tools for pig production. The critical k value at which crowding becomes detrimental to the growth of the pig is similar in full- and partial-slat systems and in nursery and grower-finisher stages. The critical point for crowding determined in these analyses approximated current recommendations to ensure the welfare of pigs.
Subject(s)
Floors and Floorcoverings/standards , Housing, Animal , Swine/growth & development , Animal Husbandry , Animal Welfare , Animals , Body WeightABSTRACT
Understanding how the voice is used in different styles of singing is commonly based on intuitive descriptions offered by performers who are proficient in only one style. Such descriptions are debatable, lack reproducibility, and lack scientifically derived explanations of the characteristics. We undertook acoustic and aerodynamic analyses of a female subject with professional experience in both operatic and Broadway styles of singing, who sang examples in these two styles. How representative the examples are of the respective styles was investigated by means of a listening test. Further, as a reference point, we compared the styles with her speech. Variation in styles associated with pitch and vocal loudness was investigated for various parameters: subglottal pressure, closed quotient, glottal leakage, H1-H2 difference (the level difference between the two lowest partials of the source spectrum), and glottal compliance (the ratio between the air volume displaced in a glottal pulse and the subglottal pressure). Formant frequencies, long-term-average spectrum, and vibrato characteristics were also studied. Characteristics of operatic style emerge as distinctly different from Broadway style, the latter being more similar to speaking.
Subject(s)
Glottis/physiology , Music , Phonation/physiology , Speech Acoustics , Speech Production Measurement , Voice Quality/physiology , Adult , Female , Humans , Vocal Cords/physiologyABSTRACT
Annelids of the genus Ophryotrocha are small opportunistic worms commonly found in polluted and nutrient-rich habitats such as harbors. Within this small group of about 40 described taxa a large variety of reproductive strategies are found, ranging from gonochoristic broadcast spawners to sequential hermaphroditic brooders. Many of the species have a short generation time and are easily maintained as laboratory cultures. Thus they have become a popular system for exploring a variety of biological questions including developmental genetics, ethology, and sexual selection. Despite considerable behavioral, reproductive, and karyological studies, a phylogenetic framework is lacking because most taxa are morphologically similar. In this study we use 16S mitochondrial gene sequence data to infer the phylogeny of Ophryotrocha strains commonly used in the laboratory. The resulting mtDNA topologies are generally well resolved and support a genetic split between hermaphroditic and gonochoristic species. Although the ancestral state could not be unambiguously identified, a change in reproductive strategy (i.e., hermaphroditism and gonochorism) occurred once within Ophryotrocha. Additionally, we show that sequential hermaphroditism evolved from a simultaneous hermaphroditic ancestor, and that characters previously used in phylogenetic reconstruction (i.e., jaw morphology and shape of egg mass) are homoplasic within the group.
Subject(s)
Evolution, Molecular , Polychaeta/genetics , Animals , Base Sequence , DNA, Mitochondrial/genetics , DNA, Ribosomal/genetics , Female , Male , Molecular Sequence Data , Phylogeny , Polychaeta/classification , Polymerase Chain Reaction , Sequence Homology, Nucleic AcidABSTRACT
We estimated the phylogenetic relationships of 15 nemertean (phylum Nemertea) species from the four subclasses Hoplo-, Hetero-, Palaeo-, and Bdellonemertea with 18S rDNA sequence data. Three outgroup taxa were used for rooting: Annelida, Platyhelminthes, and Mollusca. Parsimony and maximum-likelihood analyses supported the monophyletic status of the Heteronemertea and a taxon consisting of hoplonemerteans and Bdellonemertea, while indicating that Palaeonemertea is paraphyletic. The monophyletic status of the two nemertean classes Anopla and Enopla is not supported by the data. The unambiguous clades are well supported, as assessed by a randomization test (bootstrapping) and branch support values.
Subject(s)
Invertebrates/genetics , Phylogeny , RNA, Ribosomal, 18S/genetics , Animals , Annelida/classification , Annelida/genetics , DNA/chemistry , DNA/genetics , Invertebrates/classification , Molecular Sequence Data , Mollusca/classification , Mollusca/genetics , Platyhelminths/classification , Platyhelminths/genetics , Sequence Analysis, DNAABSTRACT
Three species of marine nemerteans described and illustrated from Queensland and the Great Barrier Reef, Australia, include one new genus and two new species: these are the monostiliferous hoplonemerteans Thallasionemertes leucocephala gen. et sp. nov. and Correanemertes polyophthalma sp. nov. A new colour variety of the heteronemertean Micrura callima is also reported, this species previously only being known from Rottnest Island, Western Australia. A key for the field identification of the marine nemerteans recorded from coastal Queensland and the Great Barrier Reef is provided.
Subject(s)
Invertebrates/classification , Animals , Invertebrates/anatomy & histology , Phylogeny , QueenslandSubject(s)
Mollusca/classification , Mollusca/genetics , Phylogeny , Animals , Biometry , Mollusca/anatomy & histologyABSTRACT
OBJECTIVE: To characterize the strength and limitations of hypodermic needles to reduce the risk of leaving broken needles in the flesh of animals. SAMPLE POPULATION: Skin of porcine cadavers. Procedure-Stainless steel needles of various gauges combined with aluminum and plastic hubs were subjected to standard test-stand conditions to compare strength under various loading regimens. A device that simulated animal motion was constructed to test breakage characteristics during animal movement. RESULTS: Needles and needle/hub assemblies were resilient to needle breakage, except when bent needles were straightened and a load reapplied. Needle gauge and length drastically affected strength. For 16-and 20-gauge needles, a 1.0-in needle was 1.6 times stronger than a 1.5-in needle. Adding animal movement for 20-gauge, 1.5-in needles resulted in a 40% increase in hub failures for plastic, compared to aluminum hub needles. CONCLUSIONS AND CLINICAL RELEVANCE: Findings of this study are important considerations for meat packers to address in their Hazard Analysis and Critical Control Points plans.
Subject(s)
Needles , Syringes , Animals , Equipment Failure/veterinary , Movement , Stress, Mechanical , SwineABSTRACT
The 16S rRNA mitochondrial gene was used to reconstruct the relationships among 10 heteronemertean species (subclass Heteronemertea, phylum Nemertea); Lineus ruber and L. viridis are represented by more than one specimen to assess intraspecific variation in these enigmatic species, and the analysis includes in total 14 terminal taxa incorporating one palaeonemertean species (Tubulanus annulatus) for outgroup rooting. The aligned sequences were subjected to maximum parsimony, maximum-likelihood, and neighbor-joining analyses to estimate the phylogenetic relationship of the species. The results were concordant from all analyses and indicate that neither Lineus nor Micrura are monophyletic taxa, and that there is no support from a phylogenetic point of view to establish the monotypic genus Riseriellus.