Influence of derived operation-specific tractor emission data on results from an LCI on wheat production

The shortage of data for emissions from agricultural tractors contributes to LCA results on environmental load from modern crop production possibly having high error levels and high uncertainties. The first part of this work describes measurements and calculations made in order to obtain operation-specific agricultural emission data. Calculations are based on emission data measured on a standard 70 kW tractor of a widely available make. In the second part, results from an LCI on wheat production based on traditionally used emission data are calculated and compared with results obtained when using the emission data for specific working operations derived in part one. One conclusion of the study is that the emission values, when related to the energy in the used fuel, show very large variations between different driving operations. Another conclusion is that the use of the new data results in a marked reduction of the total air emissions produced in the wheat production chain, especially for CO and HC, but also for NO_x and SO₂.     

Riochemical and physiological effects in farmed Baltic salmon fed lipids containing xenobiotics extracted from Baltic herring

During a 2-year experimental period female baltic salmon (Salmo salar) were fed pellets impregnated with oil extracted from Baltic herring (Clupea harengus). This extract contained lipid-soluble xenobiotics present in Baltic herring, which constitute a major part of the natural diet of Baltic salmon. The fish were examined at the time of ovulation in November each year. After 2 years of feeding, the load of polychlorinated dibenzo-paradioxins and furans in the exposed group was about twice that in the control group, but still low compared with concentrations in feral Baltic salmon. In spite of the relatively low exposure level, several vital biochemical functions were disturbed in the treated fish. Organic skeletal variables were affected indicating that the bone metabolism had been altered. Furthermore, the activities of enzymes involved in steroid biosynthesis were affected, which could lead to disturbances in reproductive functions. Splenocytes from exposed fish sampled in November 1990 showed a reduced mitogenic response, indicating that their immune system was suppressed. Feeding the salmon with pollutant-impregnated pellets also resulted in an induction of the hepatic ethoxyresorufin-O-deethylase (EROD) activity after only 6 weeks of exposure. Likewise, morphological abnormalities, i.e. hypertrophic hepatocytes and various stages of hepatic degeneration, were already apparent after 6 weeks of exposure. However, no EROD induction or morphological responses were recorded at the second and third sampling event, i.e. after one and 2 years of exposure, respectively. this could indicate that some physiological functions may adapt to a restricted xenobiotic load.     

Petrosal and inner ear anatomy and allometry amongst specimens referred to Litopterna (Placentalia)

New isolated petrosals from the Itaboraí beds of Brazil (late Palaeocene or early Eocene) are here described and referred to the early diverging litoptern Miguelsoria parayirunhor, based on phylogenetic, size, and abundance arguments. Both the external and internal anatomy of these specimens were investigated, which for the first time document many details of the auditory region of a Palaeogene litoptern. Our cladistic analysis, which included our new observations, failed to recover a monophyletic Litopterna but did not exclude it. A constrained analysis for the monophyly of this order showed that several features such as a (sub)quadrangular and anteroposteriorly elongated tensor tympani fossa and a large notch in the vicinity of the external opening of the cochlear canaliculus may constitute synapomorphies for Litopterna. The evolution of several other auditory characters amongst Litopterna is discussed and the relative dimensions of the inner ear and surrounding petrosal in the group were also investigated. This allowed detection of negative allometry of the bony labyrinth within the petrosal, which was confirmed by measurements and regression analysis across a larger sample of placental mammals. This scaling effect probably has an important influence on several characters of the bony labyrinth and petrosal, amongst which are the length of the vestibular aqueduct and cochlear canaliculus. It demonstrates that many aspects of the morphological variation of the bony labyrinth need to be thoroughly investigated before being incorporated into phylogenetic analyses. © 2015 The Linnean Society of London     

Optimal coordination and control of posture and movements

This paper presents a theoretical model of stability and coordination of posture and locomotion, together with algorithms for continuous-time quadratic optimization of motion control. Explicit solutions to the Hamilton–Jacobi equation for optimal control of rigid-body motion are obtained by solving an algebraic matrix equation. The stability is investigated with Lyapunov function theory and it is shown that global asymptotic stability holds. It is also shown how optimal control and adaptive control may act in concert in the case of unknown or uncertain system parameters. The solution describes motion strategies of minimum effort and variance. The proposed optimal control is formulated to be suitable as a posture and movement model for experimental validation and verification. The combination of adaptive and optimal control makes this algorithm a candidate for coordination and control of functional neuromuscular stimulation as well as of prostheses. Validation examples with experimental data are provided.     

Screening for species potentially sensitive to habitat fragmentation

FORUM is a lighter channel of communication between readers and contributors: it aims to stimulate discussion and debate, particularly by presenting new ideas and by suggesting alternative interpretations to the more formal research papers published in ECOGRAPHY and elsewhere. A lighter prose is encouraged and no summary is required. Contributions should be concise and to the point, with a relatively short bibliography. Formal research papers, however short, will not be considered.     

Effect of nutrient enrichment on the distribution and sedimentation of polychlorinated biphenyls (PCBs) in seawater

The effect of nutrient enrichment on the distribution of polychlorinated biphenyl's (PCBs) in the microbial food web and the residence time of PCBs in seawater was studied in an experimental mesocosm system. Two 5 m high temperature and light controlled mesocosm tubes (⊘ = 0,5 m) were filled with seawater from the northern Baltic Sea. Inorganic phosphorus and nitrogen were added daily to one mesocosm, while the other served as a control. Experiments were conducted at 5, 10 and 20°>C. Three ¹⁴C-labelled PCBs of different degree of chlorination were added to subsamples of the mesocosms: 4 chlorobiphenyl (MCB), IUPAC # 3; 2,2′,5,5′-tetrachlorobiphenyl (TCB), IUPAC # 52 and 2,2′, 4,4′,5,5′-hexachlorobiphenyl (HCB) IUPAC # 153. The biomasses and growth rates of the microorganisms as well as the sedimentation rate of particulate organic material increased with nutrient enrichment. The size distribution of the microorganisms changed with nutrient status, from dominance of picoplankton (< 2 μm) in the control towards increased importance of micro (> 10 μm) and nanoplankton (2– 10 μm) in nutrient enrichment. The specific growth rate of the bacterial community was found to be more temperature dependent than that of the phytoplankton community. The relative proportion of PCBs in the >2 μm fraction was observed to be in the order MCB < TCB < HCB, while the opposite distribution prevailed in the < 2 μm fraction. We hypothesize that this is due to the combined effect of the different Kow values of the PCBs and a different composition of the particulate organic carbon in the > 2 μm and < 2 μm fractions (e.g. different lipid composition). The residence time of the PCBs in the mesocosm generally decreased with nutrient enrichment, but was dependent on the degree of chlorination of the PCB. Our results indicate that the transport of organic pollutants up through the food web is more important in nutrient poor than in nutrient rich waters and that the importance of sedimentation is higher in eutrophic ecosystems. This revised version was published online in July 2006 with corrections to the Cover Date.     

DNA methylation of loci within ABCG1 and PHOSPHO1 in blood DNA is associated with future type 2 diabetes risk

Identification of subjects with a high risk of developing type 2 diabetes (T2D) is fundamental for prevention of the disease. Consequently, it is essential to search for new biomarkers that can improve the prediction of T2D. The aim of this study was to examine whether 5 DNA methylation loci in blood DNA (ABCG1, PHOSPHO1, SOCS3, SREBF1, and TXNIP), recently reported to be associated with T2D, might predict future T2D in subjects from the Botnia prospective study. We also tested if these CpG sites exhibit altered DNA methylation in human pancreatic islets, liver, adipose tissue, and skeletal muscle from diabetic vs. non-diabetic subjects. DNA methylation at the ABCG1 locus cg06500161 in blood DNA was associated with an increased risk for future T2D (OR = 1.09, 95% CI = 1.02–1.16, P-value = 0.007, Q-value = 0.018), while DNA methylation at the PHOSPHO1 locus cg02650017 in blood DNA was associated with a decreased risk for future T2D (OR = 0.85, 95% CI = 0.75–0.95, P-value = 0.006, Q-value = 0.018) after adjustment for age, gender, fasting glucose, and family relation. Furthermore, the level of DNA methylation at the ABCG1 locus cg06500161 in blood DNA correlated positively with BMI, HbA1c, fasting insulin, and triglyceride levels, and was increased in adipose tissue and blood from the diabetic twin among monozygotic twin pairs discordant for T2D. DNA methylation at the PHOSPHO1 locus cg02650017 in blood correlated positively with HDL levels, and was decreased in skeletal muscle from diabetic vs. non-diabetic monozygotic twins. DNA methylation of cg18181703 (SOCS3), cg11024682 (SREBF1), and cg19693031 (TXNIP) was not associated with future T2D risk in subjects from the Botnia prospective study.     

Oculomotor Deficits after Chemotherapy in Childhood

Advances in the diagnosis and treatment of pediatric malignancies have substantially increased the number of childhood cancer survivors. However, reports suggest that some of the chemotherapy agents used for treatment can cross the blood brain barrier which may lead to a host of neurological symptoms including oculomotor dysfunction. Whether chemotherapy at young age causes oculomotor dysfunction later in life is unknown. Oculomotor performance was assessed with traditional and novel methods in 23 adults (mean age 25.3 years, treatment age 10.2 years) treated with chemotherapy for a solid malignant tumor not affecting the central nervous system. Their results were compared to those from 25 healthy, age-matched controls (mean age 25.1 years). Correlation analysis was performed between the subjective symptoms reported by the chemotherapy treated subjects (CTS) and oculomotor performance. In CTS, the temporal control of the smooth pursuit velocity (velocity accuracy) was markedly poorer (p<0.001) and the saccades had disproportionally shorter amplitude than normal for the associated saccade peak velocity (main sequence) (p = 0.004), whereas smooth pursuit and saccade onset times were shorter (p = 0.004) in CTS compared with controls. The CTS treated before 12 years of age manifested more severe oculomotor deficits. CTS frequently reported subjective symptoms of visual disturbances (70%), unsteadiness, light-headedness and that things around them were spinning or moving (87%). Several subjective symptoms were significantly related to deficits in oculomotor performance. To conclude, chemotherapy in childhood or adolescence can result in severe oculomotor dysfunctions in adulthood. The revealed oculomotor dysfunctions were significantly related to the subjects’ self-perception of visual disturbances, dizziness, light-headedness and sensing unsteadiness. Assessments of oculomotor function may, thus, offer an objective method to track and rate the level of neurological complications following chemotherapy.     

Heparin and dermatan sulphate induced capacitation of frozen-thawed bull spermatozoa measured by merocyanine-540

Glycosaminoglycans (GAGs) are present in the oviduct in which the major part of sperm capacitation occurs. In this study we have tested how capacitation of frozen-thawed bull spermatozoa is effected by exposure to different GAGs detectable or possibly present in oviductal fluid; i.e. heparin, hyaluronan, heparan sulphate, dermatan sulphate and chondroitin sulphate. Following exposure of different duration, the spermatozoa were stained with either Chlortetracycline (CTC) or merocyanine-540 and evaluated with epifluorescent light microscopy or flow cytometry, respectively. Heparin elicited a significant increase in the number of alive, capacitated spermatozoa, either expressed as higher merocyanine-540 fluorescence (p < 0.0001) or as B-pattern (p = 0.0021) in the CTC assay, during 4 h of incubation. When comparing the different GAG treatments one by one to the negative control in the flow cytometric study, only heparin and dermatan sulphate were significant (p < 0.0001) higher than the control at 0-30 min of incubation. Duration of incubation did not affect the proportion of capacitated spermatozoa when measured as merocyanine-540 fluorescence or CTC B-pattern, but the length of the incubation did affect the number of dead (Yo-PRO 1 positive) spermatozoa (p < 0.0001). Exposure to zona pellucida proteins significantly increased the proportion of acrosome reacted spermatozoa (p = 0.016). Both heparin and dermatan sulphate induce capacitation of frozen-thawed bull spermatozoa in vitro.