Temperature-dependent Processes Research Articles

O(2) cost of contractility but not of mechanical energy increases with temperature in canine left ventricle.

We investigated the effects of myocardial temperature on left ventricular (LV) mechanoenergetics in the excised, cross-circulated canine heart. We used the framework of the LV contractility (E(max))-pressure-volume area (PVA; a measure of total mechanical energy)-myocardial oxygen consumption (VO(2)) relationship. We have shown this framework to be useful to integrative analysis of the mechanoenergetics of a beating heart. In isovolumic contractions at a constant pacing rate, increasing myocardial temperature from 30 to 40 degrees C depressed E(max) and increased the oxygen cost of E(max), which was enhanced by dobutamine, in a linear manner. However, the slope of the VO(2)-PVA relation (reciprocal of contractile efficiency) and its VO(2) intercept remained constant. Q(10) values of E(max), the oxygen cost of E(max), and the oxygen cost of PVA were 0.4, 2.1 and 1.0, respectively, around normothermia. We conclude that the temperature-dependent processes of cross-bridge cycling and Ca(2+) handling integratively depress E(max) and augment its oxygen cost without affecting the oxygen cost of PVA as myocardial temperature increases by 10 degrees C around normothermia.

Local recombination mechanisms in type-II GaAs/AlAs superlattices: The role of temperature-dependent transport processes

We study type-II GaAs/AlAs short-period superlattices by spatially resolved photoluminescence spectroscopy $(\ensuremath{\mu}$-PL). We observe two groups of spectrally narrow luminescence lines. The origin of one group is localized type-II states while the other group is related to deeply localized type-I states. The latter result from a local crossover of the band alignment from type-II to type-I induced by a variation of the well width of 2 bilayers. The use of nonresonant excitation and the variation of the lattice temperature give a direct access to the transport processes preceding the recombination. We can distinguish between two cases. Among the localized type-II states, phonon-assisted relaxation of the excitons is identified by a redshift of the envelope of the $\ensuremath{\mu}$-PL lines. For the deeply localized type-I states, the luminescence intensity increases exponentially with rising temperature. We model this behavior by electron tunneling into the luminescing states.

Simulating temperature-dependent ecological processes at the sub-continental scale: male gypsy moth flight phenology as an example

We simulated male gypsy moth flight phenology for the location of 1371 weather stations east of 100° W longitude and north of 35° N latitude in North America. The output of these simulations, based on average weather conditions from 1961 to 1990, was submitted to two map-interpolation methods: multiple regression and universal kriging. Multiple regression was found to be as accurate as universal kriging and demands less computing power. A map of the date of peak male gypsy moth flight was generated by universal kriging. This map itself constitutes a useful pest-management planning tool; in addition, the map delineates the potential range of the gypsy moth based on its seasonality at the northern edge of its current distribution in eastern North America. The simulation and map-interpolation methods described in this paper thus constitute an interesting approach to the study and monitoring of the ecological impacts of climate change and shifts in land-use patterns at the sub-continental level.

TEMPERATURE EFFECTS ON WASTEWATER NITRATE REMOVAL IN LABORATORY-SCALE CONSTRUCTED WETLANDS

Constructed wetlands may be used for removal of high nutrient loads in greenhouse wastewater prior to discharge into the environment. Temperature affects both the physical and biological activities in wetland systems. Since nitrification and denitrification are temperature-dependent processes, effluent nitrate concentrations will fluctuate due to changes in air and wetland temperature. In a cold climate, constructed wetlands can function in a temperature-controlled, greenhouse environment year-round. This work evaluates four temperature treatments on nitrate removal rates in five planted and five unplanted laboratory-scale wetlands. Wetlands were supplied with a nutrient solution similar to the fertigation runoff solution (100 PPM nitrate-N) used in greenhouse crop production. A first-order kinetic model was used to describe experimental nitrate depletion data and to predict nitrate removal rate constants (k) in the wetlands planted with Iris pseudocoras. The negligible removal in unplanted wetlands was thought to be due to lack of carbon source in the fertigation solution. Between 18 and 23°C in planted systems, k increased from 0.062 to 0.077 h–1, appeared to peak around 30°C (k = 0.184 h–1), but decreased at 38°C (k = 0.099 h–1). Based on the Arrhenius equation, k was a first-order exponential function of temperature between 18 and 30°C in planted systems. Quantification of temperature effects on planted and unplanted laboratory-scale constructed wetlands can be used to enhance the design and management of wastewater treatment wetlands.

Sedimentary thickness variations and deformation intensity during basin inversion in the Flinders Ranges, South Australia

The central and northern parts of the Adelaide fold belt in the Flinders Ranges, South Australia, consist of a sequence of Neo-Proterozoic–Cambrian sediments overlying a Meso-Proterozoic basement complex, both of which were mildly deformed in an intracratonic setting during the ∼500 Ma Delamerian orogeny. The fold belt lies within a prominent heat flow anomaly (average heat flows of ∼90 mWm −2) reflecting extraordinary enrichments in heat producing elements in the Meso-Proterozoic basement, suggesting that anomalous thermal regimes may have been significant in localising Delamerian deformation. However, spatial variations in deformation intensity correlate more closely with variations in the thickness of the sedimentary sequence than with observed variations in heat flow, suggesting that the thickness of the sedimentary blanket plays a crucial role in localising Delamerian deformation during basin inversion. We use simple numerical models of lithospheric strength to investigate the potential role of sedimentary thickness variations on the distribution and style of deformation, focussing on the impact of a variable thickness sediment pile deposited above a ‘radioactive’ basement. We show that for thermal parameters appropriate to the Flinders Ranges, Moho temperatures may vary by ∼25–30°C for every additional kilometre of sediment. For a ‘Brace–Goetze’ lithospheric rheology, controlled by a combination of temperature-dependent creep processes and frictional sliding, the observed variations in thickness of the sedimentary pile are sufficient to cause dramatic reductions in the vertically-integrated strength of the lithosphere (by many orders of magnitude), thereby providing a plausible explanation for observed correlation between sediment thickness and deformation intensity during basin inversion.

The reaction of isoquinolinium N-phenylimide with 1-(diethylamino)propyne and carbon disulfide

The cycloadduct 1 exists in a mobile equilibrium with isoquinolinium N-phenylimide ( 2) and CS 2. The reaction of 1 with 1-(diethylamino)propyne ( 3) afforded the 1:1:1 products 4 and 5, the latter predominating with higher CS 2 concentration. The NMR spectra and an X-ray analysis of 4 clarified the structures. The hindered rotation about the CN bond of the N, N-diethylthiocarboxamide groups is responsible for the temperature-dependent dynamic processes observed in the 1H NMR spectra of 4 and 5. In analogy with the known reaction of the ynamine 3 with CO 2, the thiocarbamoyl-thioketene 11 is assumed as key intermediate which accepts the 1,3-dipole either at the CC or the CS bond. The reaction of ynamine 3 with CS 2 in the absence of 2 provided a 2:2 product in modest yield.

Aquisição de tempos de vida de fosforescência com resolução de fase e sua aplicação ao estudo de relaxações em polímeros

We describe in this work a simple experimental set up to perform time dependent luminescence experiments in time scales from mili-seconds to seconds, based on the phase resolution of the emission signal. This system is composed by modulation of a continuous light source with an external chopper controlled by a lock-in amplifier. We exemplified the utility of the system in studies of phosphorecence emission using benzophenone dissolved in polystyrene and since the phosphorescence intensity and lifetime are temperature-dependent processes, we also studied polymer relaxation processes in the temperature range from 20 to 400K. A software that drives the spectrofluorimeter and controls both the cryosystem and the lock-in amplifier was developed.

MBE growth of quantum-size Si-dots on SiC(0001) monitored by RHEED

Due to the large misfit (20%), Si grows in Stranski–Krastanov mode on SiC(0001) leading to the formation of Si islands with quantum-size (quantum dot) dimensions in the range of 2–6 nm in height and 10–25 nm in diameter after the transition from two-dimensional (2D) to 3D growth mode at coverages >1.25 monolayers (ML). The growth mode transition and the post growth evolution of the system towards equilibrium surface conditions by dot formation was studied in real time at temperatures between 475 and 825°C and coverages in the range of 2 ML by recording the RHEED intensities of both the specular beam and the (222)-Si-bulk spot. From that we analysed the temperature-dependent dynamic processes leading to dot formation. Above 625°C, the formation of Si dots takes place within a sub-ML range above 1.25 ML. At these temperatures, the obtained activation energy of 0.6 eV for the dot growth indicates that surface diffusion is the dominant process. Below 625°C, the occurrence of RHEED specular beam intensity oscillations indicates a 2D growth mode also at higher coverages. However, after the deposition was finished, the specular beam intensity decreased, and simultaneously, a 3D Si diffraction pattern occurred due to the formation of Si islands. The activation energy for the island growth process at these lower temperatures was determined to be much higher (2.1 eV), indicating a more complex process due to the mass transfer out of the 2D layer towards the Si islands.

Evidence for biquadratic exchange interactions in GdAg1_xZnx

Copyright (c) 1997 Elsevier Science B.V. All rights reserved. We have re-examined the magnetic-phase diagram of GdAg 1−x Zn x , an intermetallic solid solution of a ferromagnet (GdZn) and an antiferromagnet (GdAg). Samples of the intermediate composition range 0.48<x<0.59 show new magnetic-ordering phenomena and all exhibit nearly the same phase diagram at the application of a magnetic field. These phase diagrams comprise two ferrimagnetic phases with ground-state magnetization values of m≃(1)/(3) and m≃(2)/(3) and one uncommon high-temperature phase which is nearly ferromagnetic but which has a finite susceptibility and therefore no spontaneous magnetization. All ordered phases seem to coexist at one multicritical point. It is argued that the observed variety of magnetic phases is due to biquadratic exchange interactions which remain as the only active ones in a situation where the ferromagnetic and antiferromagnetic bilinear interactions compensate each other. The easiest method to identify biquadratic interactions is the Curie−Weiss law of the cubic susceptibility χ 3 . However, in metallic systems the Curie−Weiss temperature regime of χ 3 is not nearly reached even at five times the ordering temperature, thus preventing the evaluation of t 3 which provides a measure for the strength of the biquadratic interaction in insulating systems. This shows that there are much stronger and strongly temperature-dependent individual biquadratic interaction processes of either sign than one might assume according to the macroscopically observed average interaction. Although the existence of the new magnetically ordered states is confirmed with magnetization, dilatometric and specific heat measurements, no corresponding neutron-diffraction intensities are observed in zero-magnetic field which points to strongly fluctuating or non-collinear magnetic structures. Since the outlined observations fall into a composition and temperature range in this random magnetic-bond system where magnetic non-equilibrium phenomena become visible, special precautions are necessary to obtain the low-temperature equilibrium magnetization curves.

Thermotaxis and protoplasmic oscillations inPhysarum plasmodia analysed in a novel device generating stable linear temperature gradients

The application of sublethal temperature gradients offers a simple, non-invasive means for in vivo studies of thermotaxis and other temperature-dependent processes in various organisms. Development, for instance, can be dramatically desynchronized, and the resulting development gradients allow to analyze physiological inter-dependencies between locally separated subsystems. For this purpose a simple device has been developed, by which a stable linear gradient of 8 °C/cm is established on an inert metal sheet with the aid of Peltier elements. The effects of linear temperature gradients on fusion, growth, and migration of plasmodia of the slime moldPhysarum polycephalum was filmed by 16 mm film time-lapse technique, and their local contraction—relaxation cycles analysed by “multistrip kymography”, which represents a graphic documentation of the spatio-temporal pattern of protoplasmic movements that occur along well-defined regions within the giant cell.Physarum plasmodia preferentially fuse, and grow, in the range of 24–26 °C. Different parts of a single macroplasmodium can simultaneously show positive and negative thermotaxis. The contraction—relaxation cycles generating the protoplasmic shuttle streaming within the network of veins essentially depend on local temperatures and are instantaneously desynchronized by the temperature gradient. Thus they cannot be controlled by a central pacemaker or an overall electric signal. However, there is a strong tendency to locally synchronize the various oscillation frequencies present within the giant cell if temperature differences do not exceed 2 °C.

Diminished neuronal damage in the rat brain by late treatment with the antipyretic drug dipyrone or cooling following cerebral ischemia.

It has been shown that changes in body core temperature several hours after a transient ischemic insult affect neuronal survival. We report that body core temperature in normal rats fluctuates over a 24-h period, while in rats subjected to 10 min transient ischemia induced by occlusion of the common carotid arteries in combination with hypotension, body temperature persistently increases to above 38.5 degrees C from 21 to 63 h following recirculation. The antipyretic drug dipyrone administered from 12 to 72 h recovery depresses body temperature to normothermic values and markedly diminishes neuronal damage in the neocortex and hippocampus when evaluated at 7 days of survival. Cooling the animals down to normothermic levels provided similar protection to that obtained with dipyrone treatment. These results suggest that hyperthermia occurring late during reperfusion aggravates delayed neuronal damage and can be effectively prevented by antipyretic drugs. The data imply that: (1) temperature-dependent processes occurring late during recovery are involved in delayed neuronal death, (2) inflammation may be an important factor in delayed neuronal death, (3) prostanoids and interleukins may contribute to this process (4) postischemic prolonged (days) temperature control is required for proper evaluation of drug therapy in brain ischemia models, and (5) fever in patients suffering brain ischemia should be impeded.

Generalized Approach to Landscape-Wide Seasonal Forecasting with Temperature-Driven Simulation Models

Determining and depicting the landscape-wide outcome of temperature-dependent ecological processes is important in the study of spatial patterns in insect ecology as well as in the efficient deployment of human and material resources for pest management. A generalized approach is proposed that consists of a temperature-driven simulation model that uses data from a limited number of strategically located points in the landscape as its input. Elevation, slope, and aspect are varied systematically for each point. Air temperature data are obtained as both real-time and climatic average data, matched with simulation points on the basis of distance, elevation, and climatic zones. Differences in latitude and elevation are compensated for with lapse rate transformations. Slope and aspect are combined into a single exposure expression, and overheating is calculated on the basis of incoming solar radiation. Landscape-wide projections of features in model output are obtained by algebraic transformation of a digital elevation model of the landscape, using a multiple regression equation relating the output feature to latitude, longitude, elevation, and exposure. The various sources of error involved in seasonal forecasting in insect ecology and management, as well as an outline of the procedure required to test the validity of landscape-wide projections, are discussed through a case study of the phenology of the spruce budworm, Choristoneura fumiferana (Clemens).

Post mortem Release of Fish White Muscle α-Actinin as a Marker of Disorganisation

α-Actinin release and its degradation from myofibrils Z-line were studied in post mortemwhite dorsal muscle from bass and sea trout stored at 4°C and 10°C. Using α-actinin specific antibodies, we show that this protein is rapidly released within the first 24 h for the two species, and reaches a plateau within 4 days. Proteolysis take place very rapidly in bass muscle yielding 80 and 40 kDa fragments from α-actinin as major bands of proteolysis. Sea trout muscle is more resistant, and muscle stored at 4°C is not significantly α-actinin degraded even 10 days after death. In the case of sea trout muscle stored at 10°C, an increasing quantity of 80 and 40 kDa fragment can be observed after the third day. These results show that release and proteolysis of α-actinin are time- and temperature-dependent processes that take place at the early stages of fish storage. Furthermore, we observed that proteolysis of α-actinin seems to be dependent on fish species. In both species studied, the early release of α-actinin comes before the degradation of released molecules, and appears as a biphasic process throughout the disorganisation ofpost mortemmuscle in fish cold-stored above 0°C.

Intermediate steps in cellular iron uptake from transferrin. II. A cytoplasmic pool of iron is released from cultured cells via temperature-dependent mechanical wounding.

A previous study described a cytoplasmic, transferrin (Tf)-free, iron (Fe) pool that was detected only when cells were mechanically detached from the culture substratum at 4 degrees C, after initial incubation with 59Fe-125I-Tf at 37 degrees C (Richardson and Baker, 1992a). The release of this internalized 59Fe could be markedly reduced if the cells were treated with proteases or incubated at 37 degrees C prior to detachment. The present study was designed to characterize this Fe pool and understand the mechanism of its release. The results show that cellular 59Fe release increased linearly as a function of preincubation time with 59Fe-Tf subsequent to mechanical detachment at 4 degrees C using a spatula. These data suggest that the 59Fe release was largely composed of end product(s) and was not an "intermediate Fe pool." When the Fe(II) chelator, dipyridyl (DP), was incubated with 59Fe-Tf and the cells, it prevented the accumulation of 59Fe that was released following mechanical detachment at 4 degrees C. Other chelators had much less effect on the proportion of 59Fe released. Examination of the 59Fe released showed that after a 4-h preincubation with 59Fe-Tf, approximately 50% of the 59Fe was present in ferritin. These data indicate that mechanical detachment of cells at 4 degrees C resulted in membrane disruptions that allow the release of high M(r), molecules. Moreover, electron microscopy studies showed that detachment of cells from the substratum at 4 degrees C resulted in pronounced membrane damage. In contrast, when cells were detached at 37 degrees C, or at 4 degrees C after treatment with pronase, membrane damage was minimal or not apparent. These results may imply that temperature-dependent processes prevent the release of intracellular contents on membrane wounding, or alternatively, prevent wounding at 37 degrees C. The evidence also indicates that caution is required when interpreting data from experiments where cells have been mechanically detached at 4 degrees C.

Coordinative Unsaturation in Chiral Organolanthanides. Synthetic and Asymmetric Catalytic Mechanistic Study of Organoyttrium and -lutetium Complexes Having Pseudo-mesoMe2Si(η5-RC5H3)(η5-R*C5H3) Ancillary Ligation1

As established by NMR, circular dichroism, and X-ray diffraction, organolanthanide complexes of the new chelating ligand Me2Si(3-Me3SiCp)[3-(−)-menthylCp]2- (Cp = η5-C5H3) preferentially adopt a single planar chiral configuration of the asymmetric metal−ligand template. Chloro complexes (S,R)-Me2Si(Me3SiCp)[(−)-menthylCp]Ln(μ-Cl)2Li(OEt2)2 (Ln = Y, Lu) were isolated diastereomerically pure by crystallization from diethyl ether. The unusual pseudo-meso configuration leads to a gross distortion from ideal C2v symmetry, evidenced by a significant deviation of ∠Sibridge−Lu−Li from linearity (158°). At least two additional epimers are detected in THF solution. Alkylation of the (S,R) epimers with LiCH(SiMe3)2 proceeds with retention of configuration, affording chiral hydrocarbyl complexes in quantitative yield. In solution, the hydrocarbyls exhibit temperature-dependent conformational exchange processes in the NMR ascribable to restricted rotation about the Ln−CH(SiMe3)2 bond. These complexes are effective pre...

Temperature and strain-rate effects on low-cycle fatigue behavior of alloy 800H

The effects of strain rate (4 × 10-6 to 4 × 10-3 s-1) and temperature on the low-cycle fatigue (LCF) behavior of alloy 800H have been evaluated in the range 750 ° to 950 °. Total axial strain controlled LCF tests were conducted in air at a strain amplitude of ± 0.30 pct. Low-cycle fatigue life decreased with decreasing strain rate and increasing temperature. The cyclic stress response behavior showed a marked variation with temperature and strain rate. The time- and temperature-dependent processes which influence the cyclic stress response and life have been identified and their relative importance assessed. Dynamic strain aging, time-dependent deformation, precipitation of parallel platelets of M23C6on grain boundaries and incoherent ledges of twins, and oxidation were found to operate depending on the test conditions. The largest effect on life was shown by oxidation processes.

Temperature dependence of processes proximal and distal to the glucose-induced [Ca2+]i rise in stimulus-secretion coupling in rat pancreatic islets.

Cooling is known to inhibit glucose-induced insulin secretion from pancreatic islets, but temperature-dependent processes in stimulus-secretion coupling remain unclear. In the present study, we examined the effects of cooling on the glucose-induced increase in cytoplasmic Ca2+ concentration ([Ca2+]i) and concomitant insulin secretion in rat pancreatic islets to analyze the temperature dependence of processes proximal and distal to the Ca2+ signal in stimulus-secretion coupling. Rat pancreatic islets were isolated and perifused. [Ca2+]i was measured using fura-2. Glucose (15 mM) caused a triphasic [Ca2+]i response in single islets at 35 degrees C: an initial decrease and a transient increase followed by a gradual increase, on which series of Ca2+ transients were frequently superimposed. Cooling to 30 and 25 degrees C caused slower and smaller [Ca2+]i responses with a Q10 (temperature coefficient) of 1.8. Glucose caused biphasic insulin secretion at 35 degrees C, which was inhibited by cooling, with a Q10 of 11.6. The ratio of glucose-induced insulin secretion to [Ca2+]i rise (IS/Ca) was calculated to represent the efficiency of Ca2+ to cause exocytosis. The Q10 value of the ratio of IS/Ca was 6.6. The Q10 values of the ratio of IS/Ca in the responses to high K+ (30 mM), carbamylcholine (100 microM) and glibenclamide (2 microM) were 5.6, 3.8, and 13.0, respectively. These values were greater than the Q10 values of corresponding [Ca2+]i responses: 1.2, 1.4, and 1.8, respectively. From these results, we conclude that cooling inhibits not only the glucose-induced [Ca2+]i rise but also Ca(2+)-activated exocytosis, and that the latter is much more sensitive to cooling than the former.

Release and uptake of vitamin B12 by asakusanori (Porphyra tenera) seaweed.

When asakusanori was incubated in artificial seawater, it released a significant amount of vitamin B12. The rate of release was very high at the beginning of incubation and steeply decreased. Four-fifths of the released B12 was a macromolecule-bound form and the rest was free form, of which some were taken up by the asakusanori tissue. Asakusanori took up the free form B12 from the incubation medium by concentration- and temperature-dependent processes. The amount of uptake increased with the time of incubation and did not attain a plateau after 4 h. The capacity was retained even after storage in frozen state for 11 months.

Ornithine Decarboxylase from Leishmania mexicana Promastigotes: Interaction with Pyridoxal 5′-Phosphate and α-Difluoromethylornithine

The catalytic properties of ornithine decarboxylase (ODC) from Leishmania mexicana as well as the interaction with its cofactor pyridoxal 5′-phosphate (PLP) and the irreversible inhibitor α-difluoromethylornithine (DFMO) have been studied using partially purified preparations of the enzyme obtained from parasite promastigotes. Leishmania extracts prepared in the presence of saturating concentrations of PLP yielded an enzyme considerably more resistant to heat inactivation and with a three-fold higher activity than the ODC obtained without the addition of cofactor. The complete removal of PLP by treatment with hydroxylamine yielded the apoenzyme which shows an absolute requirement for PLP to recover its enzymatic activity. The Km values for L-ornithine and PLP were 0.7 mM and 25 μM, respectively, while Ki for DFMO was 0.2 mM. The restoration of ODC activity from apoenzyme and cofactor seems to involve time and temperature-dependent activation processes. L. mexicana ODC has an apparent molecular mass of 240 ± 20 kDa.

Organic matter, iron and nutrient transport and nature of dissolved organic matter in the drainage basin of a boreal humic river in northern Finland

Organic carbon and iron transport into the Gulf of Bothnia and the seasonal changes in the nature of dissolved organic matter (DOM) were studied in 1983 and 1984 at the mouth of the River Kiiminkijoki, which crosses an area of minerotrophic mires in northern Finland. Organic and inorganic transport within the drainage basin was studied in the summer and autumn of 1985 and 1986, and information was also acquired on the nature of DOM by gel filtration in river, brook and peat mining water. The river water is organically coloured, with high organic matter, Fe concentrations and transport rates, while the values for phosphorus and nitrogen are low. The organic carbon concentrations increase with discharge with the major organic load restricted to the time of spring floods. The results indicate that the dissolved organic carbon (DOC) is mainly of terrestrial origin, leaching mostly from peatlands. Autochthonous DOC sources seem also to be important in summer. The DOC concentrations decrease under low flow conditions probably mainly due to sedimentation and decomposition of humic substances. The proportion of drifting algae as a particulate organic carbon (POC) source seems to increase in summer. The changes in the ratio of Fe/DOC, the colour of the DOM and the ratio of fluorescence to DOC with discharge give indications of the origin, formation, nature and fate of the DOM in the river water. Temperature-dependent microbiological processes in the formation and sedimentation of Fe-organic colloids seem to be important. Estimates are given for the amounts and transport rates of organic carbon and Fe discharged into the Gulf of Bothnia by river. High apparent molecular weight (HAMW) organic colloids are important for the organic, Fe and P transport in the basin. The gel filtration data suggest that the DOM in the water consists mainly of fulvic acids, although humic acids are also important. The apparent molecular weight of the DOM is higher than in the lakes in the area of ombrotrophic peatlands in southern Finland. Colour in this humic water increases with DOC and Fe concentrations. The results indicate an increase in the mobilization of HAMW Fe-organic colloids in the peatlands following drainage and peat mining. The transport of inorganic nitrogen from the peatlands in the area and in the river is increasing due to peat mining. The corresponding changes in the transport of organic matter, Fe and P are less marked but point in a similar direction.