Climate change-induced ecosystem disturbance: a review on sclerophyllous and semi-deciduous forests in Tunisia.

According to the sixth assessment report of the Intergovernmental Panel on Climate Change (IPCC), global climate change is now unequivocal. Tunisia, like many other countries, has been affected by climate changes, including rising temperatures, intense heatwaves, and altered precipitation regimes. Tunisia's mean annual temperatures has risen about +1.4 °C in the twentieth century, with the most rapid warming taking place since the 1970s. Drought represents a primary contributing factor to tree decline and dieback. Long-term drought can result in reduced growth and health of trees, thereby increasing their susceptibility to insect pests and pathogens. Reported increases in tree mortality point toward accelerating global forest vulnerability under hotter temperatures and longer, more intense droughts. In order to assess the effect of these climate changes on the current state of forest ecosystems in Tunisia and their evolution, an investigative study was required. Here, we review the current state of knowledge on the effects of climate change on sclerophyllous and semi-deciduous forest ecosystems in Tunisia. Natural disturbance during recent years, as well as the adaptability and resilience of some forest species to climate change, were surveyed. The Standardized Precipitation Evapotranspiration Index (SPEI) is a multi-scalar drought index based on climate data that has been used to analyse drought variability. The SPEI time scale analysis showed a negative trend over the 1955-2021 period in Tunisian forest regions. In 2021, Tunisia lost 280 km2 of tree cover to fires, which is equivalent to 26% of the total lost area between 2008 and 2021. Changing climate conditions have also affected phenological parameters, with an advance in the start of the green season (SOS) of 9.4 days, a delay at the end of the green season (EOS) of 5 days, with a consequent extended duration of the green season (LOS) by an average of 14.2 days. All of these alarming findings invite us to seek adaptation strategies for forest ecosystems. Adapting forests to climate change is therefore a challenge for scientists as well as policymakers and managers.

Effect of heat waves on embryo mortality in the pine processionary moth.

Extreme climate events such as heat waves are predicted to become more frequent with climate change, representing a challenge for many organisms. The pine processionary moth Thaumetopoea pityocampa is a Mediterranean pine defoliator, which typically lays eggs during the summer. We evaluated the effects of heat waves on egg mortality of three populations with different phenologies: a Portuguese population with a classical life cycle (eggs laid in summer), an allochronic Portuguese population reproducing in spring, and a Tunisian population from the extreme southern limit of T. pityocampa distribution range, in which eggs are laid in fall. We tested the influence of three consecutive hot days on egg survival and development time, using either constant (CT) or daily cycling temperatures (DT) with equivalent mean temperatures. Maximum temperatures (T max) used in the experiment ranged from 36 to 48°C for DT and from 30 to 42°C for CT. Heat waves had a severe negative effect on egg survival when T max reached 42°C for all populations. No embryo survived above this threshold. At high mean temperatures (40°C), significant differences were observed between populations and between DT and CT regimes. Heat waves further increased embryo development time. The knowledge we gained about the upper lethal temperature to embryos of this species will permit better prediction of the potential expansion of this insect under different climate warming scenarios.

[30 microg intrathecal clonidine prolongs labour analgesia, but increases the incidence of hypotension and abnormal foetal heart rate patterns]. / 30 microg de clonidine en intrathécal prolonge l'analgésie du travail, mais augmente l'incidence des hypotensions et des anomalies du rythme cardiaque foetal.

OBJECTIVE: To assess the efficacy of spinal clonidine combined with bupivacaine and sufentanil and its effects on maternal and foetal outcome. STUDY DESIGN: Prospective double-blind randomized study. PATIENTS AND METHODS: One hundred and five patients requesting labour analgesia had combined spinal epidural analgesia with intrathecal bupivacaine 2.5 mg and were randomly assigned to receive in addition either sufentanil 5 microg (S5), sufentanil 5 microg and clonidine 30 microg (C30), or sufentanil 10 microg (S10). Onset time, duration of analgesia, visual analogue scores, blood pressure, ephedrine requirements, heart rate, nausea, pruritus, sedation, motor block, foetal heart rate abnormalities, mode of delivery and Apgar scores were recorded. RESULTS: Mean duration of spinal analgesia was significantly longer in patients receiving spinal clonidine compared to patients in S5 group (144+/-61 min versus 95+/-37 min). The onset time of analgesia was significantly shorter in S10 group (3+/-1 min) versus C30 group (4+/-1 min) and S5 group (4+/-1 min) (P=0.002). Hypotension was significantly more frequent in C30 group (29 versus 3% and 3% in S5 and S10 groups) (p=0,001). Foetal heart rate abnormalities and sedation were also significantly more frequent in C30 group. Mode of delivery (spontaneous, instrumental or caesarean delivery) and Apgar scores were unaffected by clonidine treatment. CONCLUSION: Intrathecal clonidine 30 mug prolongs analgesia. However, it increases the incidence of hypotension, and abnormal foetal heart rate patterns. Thus, this study confirms that the use of 30 mug intrathecal clonidine for labour analgesia is not recommended.

Bilateral chylothorax following neck dissection: a new method of treatment.

Chylothorax is a serious condition with a high rate of morbidity that may lead to death. Although it is encountered more frequently with certain thoracic procedures, it is considered to be a rare complication of neck dissection. Different forms of management have been postulated; however, no consensus of treatment has been achieved. A case of severe bilateral chylothorax that developed after bilateral neck dissection in a patient with laryngeal carcinoma is presented. Somatostatin injection was successful after total parenteral nutrition failed to control the chylothorax. On the basis of this case and the review of the literature discussed here, we advocate the use of somatostatin with other conservative measures in the management of chylothorax.

Skull base meningioma: delayed extracranial presentation.

Meningiomas are common intracranial tumors that rarely extend to extracranial sites. When they occur extracranially near the skull base, their diagnosis and management represent tremendous challenges. Although the extracranial component tends to manifest at the same time as the intracranial component, this is not always the case. In the patient reported in this article, 13 years separated the diagnosis of the intracranial tumor from the appearance of an extracranial component. The clinical presentation, radiologic findings, and management of this large skull base meningioma are discussed with reference to the literature. A high index of suspicion and clinical acumen are needed to ensure that the extracranial component of these frequent tumors is discovered, especially when it presents later than the intracranial component.