Deriving Animal Behaviour from High-Frequency GPS: Tracking Cows in Open and Forested Habitat

The increasing spatiotemporal accuracy of Global Navigation Satellite Systems (GNSS) tracking systems opens the possibility to infer animal behaviour from tracking data. We studied the relationship between high-frequency GNSS data and behaviour, aimed at developing an easily interpretable classification method to infer behaviour from location data. Behavioural observations were carried out during tracking of cows (Bos Taurus) fitted with high-frequency GPS (Global Positioning System) receivers. Data were obtained in an open field and forested area, and movement metrics were calculated for 1 min, 12 s and 2 s intervals. We observed four behaviour types (Foraging, Lying, Standing and Walking). We subsequently used Classification and Regression Trees to classify the simultaneously obtained GPS data as these behaviour types, based on distances and turning angles between fixes. GPS data with a 1 min interval from the open field was classified correctly for more than 70% of the samples. Data from the 12 s and 2 s interval could not be classified successfully, emphasizing that the interval should be long enough for the behaviour to be defined by its characteristic movement metrics. Data obtained in the forested area were classified with a lower accuracy (57%) than the data from the open field, due to a larger positional error of GPS locations and differences in behavioural performance influenced by the habitat type. This demonstrates the importance of understanding the relationship between behaviour and movement metrics, derived from GNSS fixes at different frequencies and in different habitats, in order to successfully infer behaviour. When spatially accurate location data can be obtained, behaviour can be inferred from high-frequency GNSS fixes by calculating simple movement metrics and using easily interpretable decision trees. This allows for the combined study of animal behaviour and habitat use based on location data, and might make it possible to detect deviations in behaviour at the individual level.     

A Cluster-Randomized Trial of Two Strategies to Improve Antibiotic Use for Patients with a Complicated Urinary Tract Infection

Background

Up to 50% of hospital antibiotic use is inappropriate and therefore improvement strategies are urgently needed. We compared the effectiveness of two strategies to improve the quality of antibiotic use in patients with a complicated urinary tract infection (UTI).

Methods

In a multicentre, cluster-randomized trial 19 Dutch hospitals (departments Internal Medicine and Urology) were allocated to either a multi-faceted strategy including feedback, educational sessions, reminders and additional/optional improvement actions, or a competitive feedback strategy, i.e. providing professionals with non-anonymous comparative feedback on the department’s appropriateness of antibiotic use. Retrospective baseline- and post-intervention measurements were performed in 2009 and 2012 in 50 patients per department, resulting in 1,964 and 2,027 patients respectively. Principal outcome measures were nine validated guideline-based quality indicators (QIs) that define appropriate antibiotic use in patients with a complicated UTI, and a QI sumscore that summarizes for each patient the appropriateness of antibiotic use.

Results

Performance scores on several individual QIs showed improvement from baseline to post-intervention measurements, but no significant differences were found between both strategies. The mean patient’s QI sum score improved significantly in both strategy groups (multi-faceted: 61.7% to 65.0%, P = 0.04 and competitive feedback: 62.8% to 66.7%, P = 0.01). Compliance with the strategies was suboptimal, but better compliance was associated with more improvement.

Conclusion

The effectiveness of both strategies was comparable and better compliance with the strategies was associated with more improvement. To increase effectiveness, improvement activities should be rigorously applied, preferably by a locally initiated multidisciplinary team.

Trial Registration

Nederlands Trial Register 1742     

Role of Megasphaera elsdenii in the Fermentation of dl-[2-C]lactate in the Rumen of Dairy Cattle

Since Megasphaera elsdenii ferments a variable part of dl-lactate to butyrate, measurement of the percentage of dl-lactate fermented to propionate via the acrylate pathway in rumen contents will underestimate the participation of M. elsdenii in the dl-lactate fermentation. The percentage of dl-[2-C]lactate fermented via the acrylate pathway and the percentage of dl-lactate fermented to butyrate can be measured with C-FT (Fourier transform)-nuclear magnetic resonance. On the average, the contribution of M. elsdenii to dl-lactate fermentation in the rumen of dairy cattle was found to be 74% (standard deviation, 13%), but differed with animal or diet. After feeding a cow readily fermentable carbohydrates, the contribution of M. elsdenii to the fermentation of dl-lactate increased as a consequence of catabolite repression in other dl-lactate-fermenting bacteria.     

A mitochondrial-like targeting signal on the hydrogenosomal malic enzyme from the anaerobic fungus Neocallimastix frontalis: support for the hypothesis that hydrogenosomes are modified mitochondria

The hydrogenosomal malic enzyme (ME) was purified from the anaerobic fungus Neocallimastix frontalis . Using reverse genetics, the corresponding cDNA was isolated and characterized. The deduced amino acid sequence of the ME showed high similarity to ME from metazoa, plants and protists. Putative functional domains for malate and NAD⁺/NADP⁺ binding were identified. Phylogenetic analysis of the deduced amino acid sequence of the new ME suggests that it is homologous to reference bacterial and eukaryotic ME. Most interestingly, the cDNA codes for a protein which contains a 27-amino-acid N-terminus which is not present on the purified mature protein. This presequence shares features with known mitochondrial targeting signals, including an enrichment in Ala, Leu, Ser, and Arg, and the presence of an Arg at position –2 relative to amino acid 1 of the mature protein. This is the first report of a mitochondrial-like targeting signal on a hydrogenosomal enzyme from an anaerobic fungus and provides support for the hypothesis that hydrogenosomes in Neocallimastix frontalis might be modified mitochondria.     

The role of polyglucose in oxygen-dependent respiration by a new strain of Desulfovibrio salexigens

Abstract: Desulfovibrio salexigens strain Mastl was isolated from the oxic/anoxic interface of a marine sediment. Growth under sulfate-reducing conditions was accompanied by polyglucose accumulation in the cell with every substrate tested. Highest polyglucose storage was found with glucose (0.8–1.0 g polyglucose (g protein)⁻¹), but the growth rate with this substrate was very low (0.015 h⁻¹). Anaerobically grown cells of strain Mastl exhibited immediate oxygen-dependent respiration. The endogenous oxygen reduction rate was proportional to the polyglucose content. The rate of aerobic respiration of pyruvate was also directly related to the polyglucose content indicating that this organism was only able to respire with oxygen as long as polyglucose was present. Maximum oxygen reduction rates were found at air saturating concentrations and were relatively low (3–50 nmol O₂ min⁻¹ (mg protein)⁻¹). Catalase was constitutively present in anaerobically grown cells. When batch cultures were exposed to oxygen, growth ceased immediately and polyglucose was oxidized to acetate within 40–50 h. Like the oxygen reduction activity, the nitro blue tetrazolium (NBT)-reduction activity in these cells was proportional to the polyglucose content. Under anaerobic starvation conditions there was no correlation between the NBT-reduction activity and polyglucose concentration and polyglucose was degraded slowly within 240 h. The ecological significance of aerobic polyglucose consumption is discussed.     

Influence of plant species on population dynamics, genotypic diversity and antibiotic production in the rhizosphere by indigenous Pseudomonas spp

The population dynamics, genotypic diversity and activity of naturally-occurring 2,4-diacetylphloroglucinol (DAPG)-producing Pseudomonas spp. was investigated for four plant species (wheat, sugar beet, potato, lily) grown in two different soils. All four plant species tested, except lily and in some cases wheat, supported relatively high rhizosphere populations (5 x 10(4) to 1 x 10(6) CFU/g root) of indigenous DAPG-producing Pseudomonas spp. during successive cultivation in both a take-all suppressive and a take-all conducive soil. Although lily supported on average the highest population densities of fluorescent Pseudomonas spp., it was the least supportive of DAPG-producing Pseudomonas spp. of all four plant species. The genotypic diversity of 492 DAPG-producing Pseudomonas isolates, assessed by Denaturing Gradient Gel Electrophoresis (DGGE) analysis of the phlD gene, revealed a total of 7 genotypes. Some of the genotypes were found only in the rhizosphere of a specific plant, whereas the predominant genotypes were found at significantly higher frequencies in the rhizosphere of three plant species (wheat, sugar beet and potato). Statistical analysis of the phlD(+) genotype frequencies showed that the diversity of the phlD(+) isolates from lily was significantly lower than the diversity of phlD(+) isolates found on wheat, sugar beet or potato. Additionally, soil type had a significant effect on both the phlD(+) population density and the phlD(+) genotype frequencies, with the take-all suppressive soil being the most supportive. HPLC analysis further showed that the plant species had a significant effect on DAPG-production by the indigenous phlD(+) population: the wheat and potato rhizospheres supported significantly higher amounts of DAPG produced per cell basis than the rhizospheres of sugar beet and lily. Collectively, the results of this study showed that the host plant species has a significant influence on the dynamics, composition and activity of specific indigenous antagonistic Pseudomonas spp.     

Relationship between heparin binding characteristics and ability of human spermatozoa to penetrate hamster ova

Heparin binding site affinity and density on human spermatozoa were compared between fertile and infertile men with normal or abnormal results in the zona-free hamster ova-sperm penetration assay (SPA). A portion of fresh semen from fertile donors and potentially infertile men was processed through the SPA while the remainder of the ejaculate was used to quantitate heparin binding on spermatozoa. Saturation binding assays with [3H]heparin (15-375 nM) were analysed for 3 groups of men: (1) infertile patients with abnormal SPA results, (2) infertile patients with normal SPA results and (3) fertile donors. The heparin binding site density was significantly higher in men who possessed normal SPA results (infertile men and fertile donors) than in infertile men with abnormal scores in the SPA. There was no difference in heparin binding affinity between the three groups. These findings suggest that the heparin binding-site density may be related to the ability of human spermatozoa to undergo successfully the acrosome reaction.     

Primary biochemical defect in copper metabolism in mice with a recessive X-linked mutation analogous to Menkes' disease in man

The defect in Menkes' disease in man is identical to that in Brindled mice. The defect manifests itself in a accumulation of copper in some tissues, such as renal, intestinal (mucosa and muscle), pancreatic, osseous, muscular, and dermal. Hence a fatal copper deficiency results in other tissues (e.g., hepatic). The copper transport through the intestine is impaired and copper, which circumvents the block in the copper resorption, is irreversibly trapped in the above-mentioned, copper accumulating tissues where it is bound to a cytoplasmatic protein with molecular weight 10,000 daltons, probably the primary cytoplasmatic copper transporting protein. This protein shows a Cu-S absorption band at 250 nm, and the copper:protein ratio is increased. Such copper rich protein was found neither in the kidneys of the unaffected mice nor in the liver of the mice that do have the defect. Three models of the primary defect in Menkes disease are proposed.     

Selection at the Y chromosome of the African buffalo driven by rainfall

Selection coefficients at the mammalian Y chromosome typically do not deviate strongly from neutrality. Here we show that strong balancing selection, maintaining intermediate frequencies of DNA sequence variants, acts on the Y chromosome in two populations of African buffalo (Syncerus caffer). Significant correlations exist between sequence variant frequencies and annual rainfall in the years before conception, with five- to eightfold frequency changes over short time periods. Annual rainfall variation drives the balancing of sequence variant frequencies, probably by affecting parental condition. We conclude that sequence variants confer improved male reproductive success after either dry or wet years, making the population composition and dynamics very sensitive to climate change. The mammalian Y chromosome, interacting with ecological processes, may affect male reproductive success much more strongly than previously thought.     

Granzyme B is expressed in mouse mast cells in vivo and in vitro and causes delayed cell death independent of perforin

Mast cells respond to pathogens and allergens by secreting a vast array of preformed and newly synthesized mediators, including enzymes, vasoactive amines, lipid mediators, cytokines and chemokines, thereby affecting innate and adaptive immune responses and pathogenesis. Here, we present evidence that skin-, but not lung-associated primary mast cells as well as in vitro-differentiated bone marrow-derived mast cells (BMMC) express granzyme (gzm) B, but not gzmA or perforin (perf). GzmB is associated with cytoplasmic granules of BMMC and secreted after Fcepsilon-receptor-mediated activation. BMMC from wild type but not gzmB-deficient mice cause cell death in susceptible adherent target cells, indicating that the perf-independent cytotoxicity of BMMC is executed by gzmB. Furthermore, gzmB induces a disorganization of endothelial cell-cell contacts. The data suggest that activated mast cells contribute, via secreted gzmB, to cell death, increased vascular permeability, leukocyte extravasation and subsequent inflammatory processes in affected tissues.