Modélisation de la réponse des flux de respiration d'un sol forestier selon les principales variables climatiques

Modelling of the response of forest soil respiration fluxes to the main climatic variables. The objective of this article is to model the carbon dioxide (CO2) efflux to the atmosphere due to soil respiration. First, we will synthesize the main components of soil respiration fluxes as found in the literature. Then, we will present a system of automatic measurements, which was set up in a forest stand in Vielsalm (Ardennes, Belgium). This system recorded measurements of soil efflux and of climatic variables every 30 minutes. Its spatial resolution was limited to six collars of 20 cm diameter in a two-meter diameter curve. The measurements were analyzed according to their climatic components: temperature and relative soil water content. We analyzed 2 2 , 9 2 6 cycles of soil respiration measurements, and we followed a strict procedure of data selection in order to characterize soil respiration fluxes according to the main environmental components. We modelized those soil temperature-dependent fluxes with a Q1 0 function and A r r h e n i u s ' law with temperature-adjusted activation energ y, which both gave very similar results. Our best estimation for Q1 0 is 3.86 and for A in Arrhenius ' l a w, 17,479. We then adjusted two line segments beneath and beyond 0 . 2 7 m3.m- 3 of water in the soil in order to describe the response of respiration fluxes to soil moisture content. The soil temperature at 4.5 cm could explain over 86 % of the soil respiration fluxes. Relative moisture content narrows this by 2 %

Serosurvey for viruses associated with reproductive failure in newly introduced gilts and in multiparous sows in Belgian sow herds

A serosurvey for viruses associated with reproductive disorders was conducted in 25 conventional Belgian farms. Serum antibody titers for porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), porcine parvovirus (PPV), porcine enteroviruses (PEV) and swine influenza viruses (SIV) were determined in gilts and sows. All the animals were seropositive for PCV2 and >95% were seropositive for all 4 embryopathogenic PEV serotypes. Consequently, special preventive measures appear to be unnecessary for these viruses. In I farm, non-vaccinated gilts were found to run a risk of developing PPV-induced reproductive disorders. Vaccination against PPV could exclude this risk. In 10 farms, gilts seronegative for one or more specific SIV subtypes were introduced into a herd that had previously been infected with the same subtypes. Vaccination of gilts against SIV may prevent reproductive disorders in gilts and respiratory problems in their offspring. In I farm, newly purchased gilts that were possibly shedding PRRSV were introduced into a PRRSV seronegative sow herd. Serological screening prior to purchase or vaccination of the sows could have resolved this dangerous situation

Feeding behaviour of weaned pigs fed either pellets or meal: effects of the number of animals per feeding place

peer reviewe

Modelling short-term CO2 fluxes and long-term tree growth in temperate forests with ASPECTS

peer reviewedThe net ecosystem exchange (NEE) Of CO2 between temperate forests and the atmosphere governs both carbon removal from the atmosphere and forest growth. In recent years, many experiments have been conducted to determine temperate forest NEE. These data have been used by forest modellers to better understand the processes that govern CO, fluxes, and estimate the evolution of these fluxes under changing environmental conditions. Nevertheless, it is not clear whether models capable of handling short-term processes, which are mostly source-driven, can provide an accurate estimate of long-term forest growth, which is potentially more influenced by sink- and phenology-related processes. To analyse the interactions between short- and long-term processes, we developed the ASPECTS model, which predicts long-term forest growth by integrating, over time, hourly NEE estimates. Validation data consisting of measurements of NEE by eddy-covariance and forest carbon reservoir estimates were obtained from mixed deciduous and evergreen experimental forests located in Belgium. ASPECTS accurately estimated both: (1) the NEE fluxes for several years of data; and (2) the amount of carbon contained in stems, branches, leaves, fine and coarse roots. Our simulations demonstrated that: (1) NEE measurements in Belgian forests are compatible with forest growth over the course of the 20th century, and (2) that forest history and long-term processes need to be considered for accurate simulation of short-term CO2 fluxes

A single, episodic event of unilateral/bilateral scrotal swelling in a group of adult boars at an Austrian boar stud

Background Scrotal swelling is a clinical situation which can be caused by different aetiologies. In this case report, we describe a multi-week episode of unilateral and bilateral scrotal swelling in boars at an Austrian boar stud and its diagnostic work-up. Case presentation In the summer of 2020, the herd veterinarian of an Austrian boar stud reported that over a period of six weeks, five out of 70 boars presented with unilateral severe swelling of the left scrotum and three out of 70 boars with bilateral severe swelling of the left and moderate swelling of the right scrotum, respectively. A complete history was obtained and an on-site evaluation of the facility was done. Five boars were necropsied, and a variety of samples harvested for further diagnostic investigations. Infectious differential diagnoses associated with unilateral swelling of the scrotum or the testis were excluded through serological and tissue testing. In three of the five boars, histopathology revealed complete acute haemorrhagic necrosis of the left testis concurrent with strongly congested blood vessels. Review of the collected information with a group of experts in the field of boar stud management resulted with consensus that, most likely, trauma was the etiologic event causing the clinical signs and pathology. Coincident with discussion of implementing video recording cameras in the boar housing area, no further clinical cases followed. As this case occurred during the first lockdown of the COVID-19 pandemic, we propose that the distress and travelling restrictions may have contributed to frustration among boar stud workers, which was consequently expressed as misbehaviour against boars. Conclusions Once all known infectious causes of unilateral swelling of the scrotum were excluded, a critical diagnostic work-up focused on non-infectious causes. Non-infectious causes, such as trauma, need to be carefully evaluated, as it may also include human misbehaviour against boars. Summarizing all findings of this case report, the authors hypothesize that a blunt trauma was the reason for the series of mainly unilateral swelling of the scrota of boars.info:eu-repo/semantics/publishedVersio

Improved evaporative flux partitioning and carbon flux in the land surface model JULES: impact on the simulation of land surface processes in temperate Europe

The primary role of land surface models embedded in climate models is to partition surface available energy into upwards, radiative, sensible and latent heat fluxes. Partitioning of evapotranspiration, ET, is of fundamental importance: as a major component of the total surface latent heat flux, ET affects the simulated surface water balance, and related energy balance, and consequently the feedbacks with the atmosphere. In this context it is also crucial to credibly represent the CO2 exchange between ecosystems and their environment. In this study, JULES, the land surface model used in UK weather and climate models, has been evaluated for temperate Europe. Compared to eddy covariance flux measurements, the CO2 uptake by the ecosystem is underestimated and the ET overestimated. In addition, the contribution to ET from soil and intercepted water evaporation far outweighs the contribution of plant transpiration. To alleviate these biases, adaptations have been implemented in JULES, based on key literature references. These adaptations have improved the simulation of the spatio-temporal variability of the fluxes and the accuracy of the simulated GPP and ET, including its partitioning. This resulted in a shift of the seasonal soil moisture cycle. These adaptations are expected to increase the fidelity of climate simulations over Europe. Finally, the extreme summer of 2003 was used as evaluation benchmark for the use of the model in climate change studies. The improved model captures the impact of the 2003 drought on the carbon assimilation and the water use efficiency of the plants. It, however, underestimates the 2003 GPP anomalies. The simulations showed that a reduction of evaporation from the interception and soil reservoirs, albeit not of transpiration, largely explained the good correlation between the carbon and the water fluxes anomalies that was observed during 2003. This demonstrates the importance of being able to discriminate the response of individual component of the ET flux to environmental forcing

Bilateral scrotal swelling in a boar

Introduction: A 3-year-old Landrace boar with a bilateral swelling of the scrotum was submitted to the Swine clinic in August. History reported a period of hyperthermia, anorexia, depression and weight loss in May. Recovery was obtained after a treatment based on antibiotic (lincomycin and ceftiofur) and anti-inflammatory (steroid) medication injections. On July, the boar fell down after a supervised natural mating. Materials and Methods: The present poster describes our clinical approach and conclusions. Results: The boar had a good general condition and a normal appetite. Scrotal palpation was painless. The left hemiscrotum was more enlarged than the right one. Serological analysis allowed to exclude Aujeszky disease virus, Brucella suis and Chlamydia spp., the main agents responsible for orchitis in pigs. Ultrasonography revealed multiple hypoechogenic cavities around both testicles. Semen analysis performed using microscope showed azoospermia. Dissection of the scrotal tissues - performed in October - revealed the presence of kystic structures filled with serous fluid; the largest one had a diameter of approximately 15 cm. These kystic structures were surrounded by an abondant fibrous connective tissue. Histological examination showed the presence of large amount of lymphocytes and hemosiderophages around the kysts. No sign of spermatogenesis was detected in testis. An hyperplasia of the interstitial tissue in detriment to seminiferous tubules was also observed. Conclusion: These results led us to confirm the traumatic origin of the bilateral scrotal swelling observed in this boar. The lesions were the result of a partial resorption of a complex extratesticular hematoma