Desorption processes of low-molecular-weight compounds from the surface of smectites into the gas phase determine a number of processes, e.g. those involved in drug delivery and the release of herbicides. The desorption has not been investigated thoroughly and is not well understood. The present study was undertaken in order to understand better the factors influencing these desorption mechanisms. Starting with a very pure standard (Na+-rich) montmorillonite (Kunipia-F), which was exchanged against cations with different hydration properties (Ca2+, Li+, phenyltrimethylammonium, hexyltrimethyl-ammonium), the experiments explored the rate of desorption of volatiles with different chemical functionalities (water, ethanol, ethyl acetate, and toluene). The desorption was monitored by thermogravimetry and differential scanning calorimetry under isothermal conditions, and by ramping the temperature at a constant rate. The experiments were compared with numerical calculations based on finite-element methods and with analytical models. These data point to a two-step mechanism where the desorption follows the curve of the equilibrium desorption isotherms of those molecules on the montmorillonite. The bulk-like volatiles (i.e. volatiles with release kinetics close to that of the bulk liquids) were desorbed in a first step. With a decrease in the degree of coverage of the volatile on the montmorillonite, the desorption was increasingly dominated by the strength of interaction between the volatile and the interlayer cations of the montmorillonite.

Isomorphous substitutions of Mg and Fe for Al generally appear in the octahedral sheets of montmorillonite, whereas they are infrequent in kaolinite. Therefore, the release of Mg and Fe from the octahedral sheets probably happens during the transformation of montmorillonite into kaolinite, which could affect the migration of Mg and Fe from clay minerals into surrounding environments. The objective of the current study was to investigate the relationship between Mg and Fe release during the transformation of montmorillonite into kaolinite. The results showed that the d060 value of clay minerals decreased slightly, and the intensities of both the AlMg–OH and AlFe–OH bending vibrations also decreased gradually. In addition, the (Mg+Fe)/Al (major octahedral ions) atomic ratio of kaolinite was lower than that of montmorillonite, especially in identical hydrothermal products. These results indicated that Mg and Fe ions were released progressively from the octahedral sheets during the transformation of montmorillonite into kaolinite. Moreover, the changed relative concentrations of Mg and Fe ions in the supernatant solutions after hydrothermal reactions suggested a random distribution of Mg and/or Fe in the octahedral sheets of the montmorillonite. These results improve understanding of the release relationship between Mg and Fe during clay mineral evolution and of the distribution of these two ions in the octahedral sheets, as well as the chemical composition of clay minerals as an indicator of geological environments.

The objective of this project was to collect scientific data to assist in the development of guidelines for the humane relocation of threatened and endangered arboreal non-human primate species. A troop of 31 Lowland Sykes monkeys (Cercopithecus mitis albotorquatus) was habituated to fruit bait for capture in a village and relocation to a previously selected suitable site in a protected forest reserve approximately 30 km away. Sixty-five percent (n = 20) of the animals were captured and relocated. This subgroup comprised one adult male, eight adult females, two subadult females, three juvenile males, four juvenile females and two infant males. Although the relocated group originated from one single group, post-translocation telemetry signals demonstrated that it split into two groups, which established themselves approximately 2–4 km apart in their new territory; the adult male eventually became solitary. The factors of importance for the successful capture and relocation of forest primates were found to include: proper understanding of troop home-range utilisation and of social bond organisation within the troop, method and period of habituation, method of release, suitability of the new habitat with respect to the ecological niche requirements of the species in question, and the period of post-relocation monitoring.

This study evaluates the methods utilised to release and monitor three troops of rehabilitated vervet monkeys (Chlorocebus aethiops) in South Africa. In all cases, monitoring was poor and conducted over a short time-frame disallowing release outcomes to be fully assessed. Wild troops were present at two of the three locations, casting doubt upon sightings of released monkeys and indicating that the release sites chosen were unsuitable and presented disease risks to the wild vervets. Eighty-three percent of monkeys were unaccounted for at the end of monitoring. Any future releases should make use of radio or GPS collars to track the monkeys, have a planned monitoring schedule covering a period of at least one year, collect detailed data on behaviour, demographics and ecology and should follow the IUCN Guidelines for Non-Human Primate Re-introductions.

Actions to rescue, rehabilitate and release calves of manatees are the main initiatives and strategies for conservation of the species in Brazil. The survival rate of animals in a natural environment and the reproductive success, identified by birth records, are some of the indicators used to estimate the release success for manatees. This study evaluated the effectiveness of releases of West Indian manatees based on the reproductive success of rescued animals that were released back into the wild in Brazil. Twenty-two female manatees were released in the states of Alagoas (into an extinct area) and Paraíba (into an existent population) from 1994–2020. Six females gave birth to 13 calves, all in Alagoas State. The average age of the first calving event was 11.7 (±1.49) years and 8.0 (±1.41) years after release. Among the females that had more than one calving, the average was 3.6 (±1.18) years between each calving. All calves observed were born alive; nevertheless, three (23.1%) died a few weeks after birth. In general, females rehabilitated in captivity and released in the wild were able to reproduce, especially in protected areas. This study emphasizes the need to intensify actions for the conservation of manatees and their habitats in order to achieve healthier wild populations.

Large carnivores are frequently released for conservation purposes, but early efforts struggled with inadequate monitoring and reporting, resulting in poor understanding of success. Although managers have improved release practice and monitoring, the use of orphaned, captive-raised large carnivores for release remains controversial because of the potential influence of captivity and the possible lack of natural behaviours in such individuals. Yet, rehabilitating orphaned individuals for release could help mitigate pressures on vulnerable wild populations. We present a case study on the rearing, rehabilitation and release of wild-born cheetahs Acinonyx jubatus that were rescued as orphans in Namibia. Our aim was to develop a methodological framework for cheetah release planning and post-release management based on the outcome of release trials conducted during 2004–2018. Between 2001 and 2012, we rescued 86 orphaned cheetahs from the wild. Of these, 36 (42%) were selected as release candidates. We found high success rates (75–96%) of selected individuals in achieving independence post-release. Additionally, annual survival estimates for rehabilitated individuals that reached independence were comparable to those of wild counterparts described by other studies, and some rehabilitated individuals reproduced with wild conspecifics. Our findings demonstrate the ability of wild-born, captive-raised cheetahs to transition back into the wild with strategic pre- and post-release management directed towards optimizing survival. This includes selecting appropriate release candidates, forming artificial coalitions, balancing habituation levels during captivity, choosing appropriate release sites, and providing strategic support during post-release monitoring. We encourage scientists and managers to implement and refine our protocol for rehabilitation throughout the cheetah's current and historic range.

Generally, 14C is produced in all types of reactors, mainly through neutron-induced reactions with isotopes of carbon, nitrogen, and oxygen. These isotopes are present in the fuel, fuel cladding, coolant, moderator, and structural materials of the reactor. Irradiated graphite contains a range of activation products but, from the point of view of geological disposal, another radionuclide which has to be taken into account is tritium (3H or T), produced through the neutron induced reaction Li(n,α)T. In this study we have investigated the release of 14C and 3H into the solution phase from two intact samples of irradiated graphite which have been cut from the thermal column disc located near the VVR-S reactor core. To evaluate 14C and 3H long-term release in solution the graphite samples were submerged in a solution of 0.1 M of sodium hydroxide. The experimental results regarding the release of 14C and 3H from VVR-S irradiated graphite to liquid phase show that a major fraction of the total release occurs in the first months and a slower release on a long time scale. However, these results should be applied cautiously for long time prediction.

Kochia control in continuous corn became increasingly difficult in experimental plots where isoxaflutole was used PRE for 8 yr. Studies were conducted to determine if poor kochia control resulted from an escape mechanism based on different germination rates or from a difference in sensitivity to isoxaflutole. Germination at constant temperatures showed that the kochia population in the experimental plot had greater seed dormancy compared with populations growing in adjacent fields. Germination at 25 C for seeds collected from the isoxaflutole-treated area was near 20% after 20 d, whereas germination for the other populations was above 80%. The optimal temperatures to release seed dormancy for seeds from the experimental plot were alternating 35/25 C day/night temperatures. The kochia biotype that predominated where isoxaflutole was applied PRE had elevated levels of seed dormancy and required higher alternating temperatures to release dormancy than untreated control kochia. These characteristics were unique and not found in populations never exposed to isoxaflutole. Chlorophyll content was measured to determine if differences in sensitivity to isoxaflutole existed among biotypes. Absorption at 660 nm by photosynthetic pigments was similar among the biotypes at increasing herbicide rates, indicating no differences in sensitivity to isoxaflutole among populations. Reduced kochia control in the experimental plot was due to delayed seed germination, which allowed isoxaflutole to degrade before seeds germinated. The rapid herbicide dissipation from soil can be attributed in part to coarse soils, soil moisture, and the low isoxaflutole rate.

In the eutrophic Lake Kasumigaura in Japan, a trend of dissolved Si (DSi) concentration was detected over the last three decades, probably caused by the DSi release enhanced by an increase in sediment resuspension for the same period (Arai et al., Limnol., 13, 81–95, 2012). The present study described the long-term trends of the magnitude and seasonality of diatom blooms in the lake during 1981–2010 using the database and assessed the influencing factors for the trends by the numerical simulation of DSi and diatoms. The box model was developed based on the lake budgets (inflow, outflow, release and sedimentation) and the simple diatom growth model depending on DSi, temperature and light condition. As results, database analysis detected a long-term trend of increasing diatom abundance and a shift of blooming season from spring and autumn to the winter–spring period. Si could be regarded as a main nutrient factor limiting diatom growth by analyzing N:P:Si ratios. Our model simulation relatively well-reproduced the increasing trend and the shift of seasonality of DSi and diatoms, even though peaks of diatom blooms were underestimated in some years. Among input variables, the concentration of resuspended sediments radically increased. The model simulation with the input variables or parameters changed suggested as follows: (1) the recent DSi release from resuspended sediments enhanced diatom abundance and (2) the degradation of light condition caused by resuspension affected the shift of blooming season. These findings implicate the significance of the interactions between sediments and water to phytoplankton blooms.

L'influence de Tubificidae du genre Tubifex sur le relargage des différentes formes du phosphore (particulaire, organique dissous et orthophosphates) a été étudiée au laboratoire, en conditions contrôlées. Lorsque le milieu est oxygéné, les vers entraînent une augmentation du phosphore particulaire dans la colonne d'eau mais aux dépens des orthophosphates, de sorte que le relargage de phosphore total n'est guère supérieur à celui du témoin. En milieu appauvri en oxygène, la différence est plus nette mais elle est surtout due au phosphore particulaire plus abondant. Ce phosphore particulaire semble provenir d'une agitation plus importante car la défécation est réduite par le déficit en oxygène. Le transfert apparent orthophosphates-phosphore particulaire pose le problème de la biodisponibilité de ce dernier qui conditionne l'action positive ou négative des Tubifex sur la nutrition algale.

La neurotransmission de sérotonine (5-HT) est régulée, via un rêtro-contrôle négatif, par des réceptcurs situés an niveau du raphé nucleus et des terminaisons neuronales. Ces autorécepteurs sérotoninergiques ont été étudiés aux niveaux comportemental, électrophysiologique et biochimique. Les réponses comportementales et électropliysiologiques sont atténuées par l'administration chronique des antidépresseurs. De plus, in vitro, les inhibiteurs de capture de 5-HT atténuent l'aulorégulation de la libération de [3H]5-HT. La présente étude concerne l'effet, sur cette libération induite par stimulation électrique de l'hypothalamus; de rat et sa modulation, de l'administration chronique de 2 antidépresseurs, le citalopram, inhibiteur spécifique de la capture de 5-HT, et le milnacipran (anciennement midalcipran, F 2207), qui bloque la capture de 5-HT et de noradrénaline avec la même puissance. Le eitalopram était administré à 50 et à 10 mg/kg/j pendant 21 jours et 24 h après, les rats étaient décapités, des coupes d'hypoihalamus incubées avec la [3H]5-HT, superfusées avec une solution de Krebs et stimulées électriquement. La quantité de [3H]5-HT libélée par stimulation électrique étail augmented et l'effet inhibiteur de l'agoniste, LSD, diminué chez les rats traités. Ces effets étaient présents aux 2 doses mais plus marqués à la forte dose. Donc un traitement chronique avec le citalopram provoque une «down-regulation» de l'autorécep-teur sérotonergique, permettant ainsi une augmentation de la neurotransmission de 5-HT. Cet effet peut expliquer, an moins en partie, l’action antidépressive de ce produit et it esl possible qu'il représente un mécanisme fondamental à beaucoup d'antidépresseurs qui inhibent la capture de 5-HT. Cependant, après 21 jours de traitement avec le milnacipran, à 50 mg/kg/j, aucun des paramétres étudiés n'était modifié. Cela suggère que l’hypothèse de la «down-regulation» de l’autorècepteur n'est pas l'hypothèse universelle qui explique l’action de tous les antidépresseurs agissant sur la capture de 5-HT.