By-catch and drowning in harbour porpoises (<Emphasis Type="Italic">Phocoena phocoena</Emphasis>) stranded on the northern Dutch coast

Stranding data and recorded post-mortem findings were studied for 153 harbour porpoises (Phocoena phocoena), which were collected by the Seal Rehabilitation and Research Centre (SRRC; Pieterburen, The Netherlands) in the period 1984–2006. Special consideration was given to ‘by-catch’ listed as a major cause of death. A distinct increase in the numbers of strandings of porpoises along the Dutch coastline has occurred in the recent years of the studied period. This corresponds to the number of porpoises observed in Dutch waters in the same period. Although strandings occurred throughout the entire year, they were most frequent during the January to July period. By-catch and drowning were noted most frequent in the winter and spring seasons (December–April). By-catch and drowned porpoises were found along the entire Dutch coastline. The numbers of animals per area varied depending on the collection efforts. At post-mortem investigation, three probable causes of death were identified most frequently: pneumonia, emaciation and by-catch/drowning. The by-catch and drowning rate was calculated to vary between 7% and 19%. Overall, the percentages obtained from this study appeared to be in line with those established by others in neighbouring countries. Varying fishing techniques are used in Dutch waters. A careful study of the fishing methods involved and close co-operation with fishermen are required to determine effective measures to reduce the by-catch of porpoises.     

The state of the environment of the Loosdrecht lakes

The Loosdrecht lakes are a system of shallow, interconnected, peat lakes in the centre of The Netherlands. The main environmental functions of the Loosdrecht lakes are nature and recreation. From the point of view of the Dutch policy, a Specific Environmental Quality (Bijzondere Milieukwaliteit) should be set for these lakes.The most serious environmental problem of the area is eutrophication. The Loosdrecht lakes have, by increasing external phosphorus loading, changed, from clear lakes with few macrophytes, followed by a period of abundant characean growth, to turbid lakes dominated by cyanobacteria and detrital matter. Eutrophication was counteracted by use of sewerage systems and dephosporization of the supply water. The resultant decrease in external phosphorus loading did not result in a decrease of turbidity by suspended particles.The eutrophication of the lake ecosystems was described as a series of phases. One of those phases, the status around 1940, has been used as an ecological reference system.By means of a graphical presentation technique, the so-called AMOEBE-approach, the state of the environment of the Loosdrecht lakes has been visualized. Thirty-two ecological parameters, including both biotic and abiotic factors, have been selected and quantified. Concrete target values for these parameters have been derived from historical reports and from Lake Western Loenderveen, located close to the Loosdrecht lakes, but less eutrophic.The general conclusion is that the state of the environment of the Loosdrecht lakes is far from what is required with respect to a Specific Environmental Quality, as many of the selected parameters, like water transparency, total phosphorus, mineral nitrogen, cyanobacteria, bream, pike, macrophytes, birds and otter, deviate by over an order of magnitude from their desired levels.     

Adult spinal opioid receptor μ1 expression after incision is altered by early life repetitive tactile and noxious procedures in rats

Clinical and experimental data suggests that noxious stimulation at critical stages of development results in long‐term changes on nociceptive processing in later life. Here, we use an established, well‐documented rat model of repetitive noxious procedures closely mimicking the clinical situation in the NICU. In order to understand molecular changes underlying the long‐term consequences of repetitive stimulation of the developing nociceptive system the present study aims to analyze the presence of the µ‐opioid‐receptor‐1 (OPRM1). Neonatal rats received either four needle pricks per day in the left hind‐paw from postnatal day 0–7 as a model of procedural pain in infancy. Control pups were handled in the same way but were instead tactile stimulated, or were left undisturbed. At the age of 8 weeks, all animals received an ipsilateral hind‐paw incision as a model for post‐operative pain, and mechanical sensitivity was tested at multiple time‐points. Before, and 1 or 5 days post‐incision, spinal cord tissue was collected for immunostaining of opioid receptor OPRM1. Semi‐quantitative immunocytochemical analysis of superficial laminae in lumbar spinal dorsal horn revealed that: (1) early life repetitive tactile or noxious procedures do not alter baseline levels of OPRM1 staining intensity and (2) early life repetitive tactile or noxious procedures lead to a decrease in OPRM1 staining intensity 5 days after incision in adulthood compared to undisturbed controls. We conclude that early life repetitive tactile or noxious procedures affect the intensity of OPRM1‐immunoreactivity in the lumbar superficial spinal cord dorsal horn after adulthood injury, without affecting baseline intensity. © 2018 The Authors. Developmental Neurobiology Published by Wiley Periodicals, Inc. Develop Neurobiol 78: 417–426, 2018     

Quantifying the Precision of Single-Molecule Torque and Twist Measurements Using Allan Variance

Single-molecule manipulation techniques have provided unprecedented insights into the structure, function, interactions, and mechanical properties of biological macromolecules. Recently, the single-molecule toolbox has been expanded by techniques that enable measurements of rotation and torque, such as the optical torque wrench (OTW) and several different implementations of magnetic (torque) tweezers. Although systematic analyses of the position and force precision of single-molecule techniques have attracted considerable attention, their angle and torque precision have been treated in much less detail. Here, we propose Allan deviation as a tool to systematically quantitate angle and torque precision in single-molecule measurements. We apply the Allan variance method to experimental data from our implementations of (electro)magnetic torque tweezers and an OTW and find that both approaches can achieve a torque precision better than 1 pN · nm. The OTW, capable of measuring torque on (sub)millisecond timescales, provides the best torque precision for measurement times$\mathrm{?}$10 s, after which drift becomes a limiting factor. For longer measurement times, magnetic torque tweezers with their superior stability provide the best torque precision. Use of the Allan deviation enables critical assessments of the torque precision as a function of measurement time across different measurement modalities and provides a tool to optimize measurement protocols for a given instrument and application.     

Brain-corticosteroid hormone dialogue: Slow and persistent

Summary 1. The stress response system is shaped by genetic factors and life experiences, of which the effect of a neonatal life event is among the most persistent. Here we report studies focused on the nature-nurture question using rat lines genetically selected for extreme differences in dopamine phenotype as well as rats exposed as infants to the traumatic experience of maternal deprivation.2. As key to the endocrine and behavioural adaptations occurring in these two animal models the hormone corticosterone (CORT) is considered. The stress hormone exerts slow and persistent genomic control over neuronal activity underlying the stress response system via high affinity mineralocorticoid (MR) and glucocorticoid receptors (GR). This action is exerted in a coordinate manner and involves after stress due to the rising CORT levels progressive activation of both receptor types.3. Short periods of maternal separation (neonatal handling) trigger subsequently enhanced maternal care and sensory stimulation. However, a prolonged period (24h) of depriving the infant of maternal care disrupts the stress hyporesponsive period (SHRP) and causes an inappropriate rise in CORT. During development exposure to CORT and to sensory stimulation has long-lasting consequences for organization of the stress response system.4. We find that these factors embodied by mother-pup interaction are critical for dopamine phenotype, CORT receptor dynamics and neuroendocrine regulation in adult life. The findings provide a conceptual framework to study dopamine-related psychopathology against a background of genetic predisposition, early life events, stress hormones and brain development.     

The distribution of nitrate reductase in tomato (Lycopersicon esculentum) leaves as affected by age

The distribution of nitrate reductase (NR, EC 1.6.6.1.) in the leaves of single-stem tomato plants ( Lycopersicon esculentum Mill., cv. Vandenbergs Moneydor) was studied using an in vitro test. The activity decreased from young to old leaves. However, a low value (NR minimum) occurred in some leaves below the apex, usually in the almost completely expanded leaves, provided that the plants received sufficient nitrate to induce optimum NR activity in all the leaves. When insufficient nitrate was available there was NR in the young leaves only. The observed NR minimum coincided with a low value for soluble carbohydrates and amino acids. Since there was no extra export of labelled carbon from the leaves with the NR minimum, it is suggested that in the almost completely expanded leaves carbohydrates produced by photosynthesis are mainly used for the production of polysaccharides for new cell walls. Consequently, less are left for the production of keto acids, which can act as acceptors for reduced nitrogen. Therefore, less amino acids are produced, and this may result in a lowered protein synthesis, including a lowered synthesis of nitrate reductase.     

Effects of Benzyladenine on Bean Leaf Senescence and the Translocation of 14C-Assimilates

Treating primary leaves of bean plants with benzyladenine (BA) greatly increased the retention of photosynthetic assimilates in the treated leaves. Within 24 hours of treatment, the BA treated primary leaves retained 70 % of their assimilates and maintained this high level throughout the period studied. In contrast, the primary leaves of control plants retained 30 % at week 2, increased retention to 80 % between week 4 and 5 and dropped to 50 % during senescence at week 6. When the trifoliate leaves of 5 week old plants were fed ¹⁴CO₂, less than 1 % of the total activity was recovered from the BA treated leaves. It is concluded that the retardation of leaf senescence by BA on intact plants is not due to mobilization of metabolites from other plant parts, but is associated with a high retention of photosynthates.     

Comparative Fungitoxic and Plant Growth Regulating Properties of Triazole Derivatives

The triazol derivatives, S-3307, S-3308, triadimefon, triadimenoland paclobutrazol are recommended for use as either fungicidesor plant growth regulators. However, in varying degrees theyexhibit both properties. In a comparative study with 5 differentfungi, S-3308 followed by S-3307 were the most fungitoxic (invitro) whereas S-3307 and paclobutrazol were the most activeplant growth retardants in bean (Phaseolus vulgaris L.) andKentucky bluegrass (Poa pratensis L.). (Received September 24, 1985; Accepted November 26, 1985)     

Evidence based selection of housekeeping genes

For accurate and reliable gene expression analysis, normalization of gene expression data against housekeeping genes (reference or internal control genes) is required. It is known that commonly used housekeeping genes (e.g. ACTB, GAPDH, HPRT1, and B2M) vary considerably under different experimental conditions and therefore their use for normalization is limited. We performed a meta-analysis of 13,629 human gene array samples in order to identify the most stable expressed genes. Here we show novel candidate housekeeping genes (e.g. RPS13, RPL27, RPS20 and OAZ1) with enhanced stability among a multitude of different cell types and varying experimental conditions. None of the commonly used housekeeping genes were present in the top 50 of the most stable expressed genes. In addition, using 2,543 diverse mouse gene array samples we were able to confirm the enhanced stability of the candidate novel housekeeping genes in another mammalian species. Therefore, the identified novel candidate housekeeping genes seem to be the most appropriate choice for normalizing gene expression data.