Calcification of Intervertebral Discs in the Dachshund: A Radiographic Study of 21 Stud-Dogs

The vertebral columns of 21 clinically normal, 4.9 to 13.2 year old dachshunds were x-rayed. This sample represented 55.3% of all male dachshunds with 20 or more offspring registered with the Norwegian Kennel Club in the period 1985-1989. Calcified intervertebral discs were identified in 9 (42.9%) of the stud-dogs, and the number of calcified discs in each individual varied from 2 to 5 with a mean of 3.7. The frequency of stud-dogs with 1 or more calcified discs was compared with the corresponding frequency in a material of 327 one-year-old dachshunds. In this comparison, the relative risk was estimated with 95% confidence bounds. When the different composition of size and coat varieties in the 2 materials was not considered, the relative risk of calcified discs was found to be 1.77 (0.99-3.2) times higher in stud-dogs than in young dogs. When the different composition of varieties in the 2 materials was considered, the relative risk was found to be 1.9 (1.1-3.4) times higher in stud-dogs than in young dogs. The results of the present study strongly suggest that an increase in the frequency of dachshunds with 1 or more calcified intervertebral discs occurs after 1 year of age.     

Colonial breeding and speciation in birds

Summary It was recently suggested that bird species which breed colonially might be under stronger sexual selection, have faster rates of evolution and might therefore speciate more rapidly than bird species which do not. If true, then colonial taxa should contain more species than non-colonial taxa, other things being equal. When similarity through common descent is accounted for, there is little evidence for an association between the number of species in a clade and whether it is colonial or not.     

Nonlinearity in interspecific interactions in response to climate change: Cod and haddock as an example

Climate change has profound ecological effects, yet our understanding of how trophic interactions among species are affected by climate change is still patchy. The sympatric Atlantic haddock and cod are co‐occurring across the North Atlantic. They compete for food at younger stages and thereafter the former is preyed by the latter. Climate change might affect the interaction and coexistence of these two species. Particularly, the increase in sea temperature (ST) has been shown to affect distribution, population growth and trophic interactions in marine systems. We used 33‐year long time series of haddock and cod abundances estimates from two data sources (acoustic and trawl survey) to analyse the dynamic effect of climate on the coexistence of these two sympatric species in the Arcto‐Boreal Barents Sea. Using a Bayesian state‐space threshold model, we demonstrated that long‐term climate variation, as expressed by changes of ST, affected species demography through different influences on density‐independent processes. The interaction between cod and haddock has shifted in the last two decades due to an increase in ST, altering the equilibrium abundances and the dynamics of the system. During warm years (ST over ca. 4°C), the increase in the cod abundance negatively affected haddock abundance while it did not during cold years. This change in interactions therefore changed the equilibrium population size with a higher population size during warm years. Our analyses show that long‐term climate change in the Arcto‐Boreal system can generate differences in the equilibrium conditions of species assemblages.     

Identification of stool proteins in C57BL/6J mice by two-dimensional gel electrophoresis and MALDI-TOF mass spectrometry

Gastrointestinal disease is a major cause of mortality in humans and animals, and the detection of disease-associated protein in stool is an established diagnostic method in this context. Yet, no data currently exists about the protein composition of mammalian faeces. Using a newly developed two-dimensional (2D) gel method, 28 of the most abundant proteins in murine faeces were identified. Mammalian faeces contains protein from multiple species (from the individual, from gastrointestinal bacteria, from food, etc.). Yet, it was found that the majority of mouse stool proteins were of mouse origin, with a minority of proteins being derived from food (in particular soybean glycinin and conglycinin) and bacteria (flagellin). Most mouse proteins were proteases and saccharidases derived from the exocrine pancreas. In addition, two unexpected mouse proteins were identified: one was a newly described mucin-like protein from intestinal goblet cells (FcγBP); the other was the secreted form of carbonic anhydrase (type VI) from salivary gland. The data suggest that 2D analysis of faecal protein is likely to provide meaningful information about the physiological stage of the gastrointestinal tract. Compared with studies based on biopsies, faecal protein analysis may reduce the number of laboratory animals, and might also allow quicker bridging from animal studies to humans, where biopsy material is more difficult to obtain and is less relevant for general practice use.     

Antimicrobial activity and structure of a consensus human β-defensin and its comparison to a novel putative hBD10

The spread of multidrug resistant bacteria owing to the intensive use of antibiotics is challenging current antibiotic therapies, and making the discovery and evaluation of new antimicrobial agents a high priority. The evaluation of novel peptide sequences of predicted antimicrobial peptides from different sources is valuable approach to identify alternative antibiotic leads. Two strategies were pursued in this study to evaluate novel antimicrobial peptides from the human β-defensin family (hBD). In the first, a 32-residue peptide was designed based on the alignment of all available hBD primary structures, while in the second a putative 35-residue peptide, hBD10, was mined from the gene DEFB110. Both hBDconsensus and hBD10 were chemically synthesized, folded and purified. They showed antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Mycobacterium tuberculosis, but were not hemolytic on human red blood cells. The NMR-based solution structure of hBDconsensus revealed that it adopts a classical β-defensin fold and disulfide connectivities. Even though the mass spectrum of hBD10 confirmed the formation of three disulfide bonds, it showed limited dispersion in ¹H NMR spectra and structural studies were not pursued. The evaluation of different β-defensin structures may identify new antimicrobial agents effective against multidrug-resistant bacterial strains.     

Late Ordovician brachiopods from eastern North Greenland: equatorial offshore migration of the Red River fauna

Abstract: Late Ordovician rhynchonelliformean brachiopods, typical of the North American Red River fauna, are found sporadically in the Børglum River Formation of the Centrum Sø area, Kronprins Christian Land, eastern North Greenland. The geographical distribution of this characteristic brachiopod fauna is thus extended to the easternmost extremity of the Laurentian craton. The assemblage compares specifically with the Hiscobeccus brachiopod fauna, based on key taxa such as notably Hiscobeccus gigas (Wang, 1949), and indicates a late Katian age for this part of the succession. For the first time, this typically inland, shallow‐water fauna is found associated with genera like Bimuria, suggesting a transitional marginal facies with outer shelf benthos. The current study describes a Hiscobeccus fauna that lived at the seaward edge of its preferred habitat. Furthermore, an unpublished Hiscobeccus fauna, from the Børglum River Formation of Peary Land, central North Greenland, as well as several occurrences from the Kap Jackson and Cape Calhoun formations in various parts of Washington Land, western North Greenland, are described here. These show a distinct shift from older strata containing H. capax (Conrad, 1842) to younger strata exclusively yielding specimens of H. gigas. As H. gigas occurs in the upper part of the Cape Calhoun Formation in Washington Land, it indicates that the upper boundary of the Cape Calhoun Formation is considerably younger than previous estimates, reaching into the uppermost Katian (middle Cautleyan–Rawtheyan). The Cape Calhoun Formation correlates with the upper member of the Børglum River Formation and further demonstrates that the Hiscobeccus fauna was widespread in Laurentian marginal settings of North Greenland. Even though the Hiscobeccus fauna was pan‐continental during the late Katian (Richmondian), it possesses a strong provincial signal during the later Ordovician. The new occurrences indicate that this fauna extended to the north‐eastern margin of the Laurentian Craton. It lived in close association with cosmopolitan faunal elements that may have been the earliest sign of the succeeding invasion of migrants from Baltica that arrived later during the Hirnantian. The offshore migration of this atypical Hiscobeccus fauna likely demonstrates the path of warm‐water currents as the Centrum Sø locality was located at the equator during the Late Ordovician.     

Fertility of gynogenetic Atlantic cod (Gadus morhua L.)

In order to investigate whether meiotic gynogenetic Atlantic cod is fertile and able to produce viable offspring, meiotic gynogenetic females were produced in spring 2010 by activating cod eggs using irradiated sperm. The extrusion of the second polar body was prevented by the application of hydrostatic pressure (56.6 MPa) 36 min after fertilization. In February 2012, their mean round weight was 972 g, and 2580 g in March 2013. In 2012, when the fish were 2 years old, about 52% were mature, 33% were immature, and 13% had undifferentiated gonads. One year later, 77% were mature, 11% were immature, and 11% had undifferentiated gonads. Several of the mature females had malformed gonads, with only one developed ovary lobe or with the two lobes fused. The mean gonadosomic index (GSI) of the 2‐year‐old mature females was 5.2%, with an estimated relative fecundity of 581 000 eggs kg ovary‐free wet weight^?1. Females were stripped for eggs when 2 and 3 years old (2012 and 2013), and fertilized with sperm from normal males. Offspring were obtained from 12 of 17 and 12 of 15 egg batches incubated in 2012 and 2013, respectively, proving that the gynogenetic females are fertile. Furthermore, larvae in all but one of the hatched groups from 2013 had commenced feeding 2 h after being startfed using rotifers 4 days after hatch, indicating viable offspring.