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While climate change has been shown to impact several life-history traits of wild-living animal populations, little is known about its effects on dispersal and connectivity. Here, we capitalize on the highly variable flooding regime of the Okavango Delta to investigate the impacts of changing environmental conditions on the dispersal and connectivity of the endangered African wild dog (Lycaon pictus). Based on remote sensed flood extents observed over 20 years, we derive two extreme flood scenarios: a minimum and a maximum flood extent, representative of very dry and very wet environmental periods. These conditions are akin to those anticipated under increased climatic variability, as it is expected under climate change. Using a movement model parameterized with GPS data from dispersing individuals, we simulate 12,000 individual dispersal trajectories across the ecosystem under both scenarios and investigate patterns of connectivity. Across the entire ecosystem, surface water coverage during maximum flood extent reduces dispersal success (i.e., the propensity of individuals to disperse between adjacent subpopulations) by 12% and increases dispersal durations by 17%. Locally, however, dispersal success diminishes by as much as 78%. Depending on the flood extent, alternative dispersal corridors emerge, some of which in the immediate vicinity of human-dominated landscapes. Notably, under maximum flood extent, the number of dispersing trajectories moving into human-dominated landscapes decreases by 41% at the Okavango Delta's inflow, but increases by 126% at the Delta's distal end. This may drive the amplification of human-wildlife conflict. While predicting the impacts of climate change on environmental conditions on the ground remains challenging, our results highlight that environmental change may have significant consequences for dispersal patterns and connectivity, and ultimately, population viability. Acknowledging and anticipating such impacts will be key to effective conservation strategies and to preserve vital dispersal corridors in light of climate change and other human-related landscape alterations.
Assuntos
Distribuição Animal , Mudança Climática , Ecossistema , Inundações , Animais , Canidae/fisiologia , Espécies em Perigo de ExtinçãoRESUMO
Integrated step-selection analyses (iSSAs) are versatile and powerful frameworks for studying habitat and movement preferences of tracked animals. iSSAs utilize integrated step-selection functions (iSSFs) to model movements in discrete time, and thus, require animal location data that are regularly spaced in time. However, many real-world datasets are incomplete due to tracking devices failing to locate an individual at one or more scheduled times, leading to slight irregularities in the duration between consecutive animal locations. To address this issue, researchers typically only consider bursts of regular data (i.e., sequences of locations that are equally spaced in time), thereby reducing the number of observations used to model movement and habitat selection. We reassess this practice and explore four alternative approaches that account for temporal irregularity resulting from missing data. Using a simulation study, we compare these alternatives to a baseline approach where temporal irregularity is ignored and demonstrate the potential improvements in model performance that can be gained by leveraging these additional data. We also showcase these benefits using a case study on a spotted hyena (Crocuta crocuta).
RESUMO
INTRODUCTION: Inguinal lymph nodes dissection (ILND) is recommended in patients presenting with high-risk penile (PC) or vulvar cancers (VC). Though, this surgical procedure is underused because of its anticipated morbidity. Minimally invasive approaches were proposed to minimize complications associated with open surgery. In this review, we analyze current available data exploring intra and perioperative outcomes of robot-assisted ILND (RAIL). EVIDENCE ACQUISITION: On April 9th, 2023, a literature search was conducted using the PubMed and Scopus databases. The search employed the combination of the following terms: ("robotic assisted" OR "robot-assisted" OR "robotic") AND ("inguinal lymph node dissection" OR "lymphadenectomy") AND ("penile cancer" OR "vulvar cancer"). Out of the 404 identified articles, 18 were used for the present scoping review and their results were reported according to the PRISMA statement. EVIDENCE SYNTHESIS: Data on 171 patients, ranging in age from 32 to 85 years, were obtained. Most of them (90.6%) harbored a penile squamous cell carcinoma and presented with no palpable nodes (85%). Operation time (OT) ranged between 45 and 300 min. Estimated blood loss varied from 10 to 300 mL. One single intra-operative complication was reported and one conversion to open was recorded. The lymph nodes (LNs) count spanned from 3 to 26 per groin, with 17 studies reporting a median yield >7 nodes. Hospital stay was 1-7 days, while the duration of drainage ranged from 4 to 72 days. Post-operative complications included lymphocele (22.2%; 0-100%), lymphedema (13.4%; 0-40%), cellulitis (11.1%; 0-25%), skin necrosis (8.7%; 0-15.4%). seroma (3.5%; 0-20%) and wound breakdown/wound infection (2.9%; 0-10%). Out of the included studies, 7 provided at least a 12-month follow-up, with recurrence-free rates ranging from 50% to 100% in patients affected by penile cancer and from 92% to 100% in vulvar cancer patients. CONCLUSIONS: The available evidence on RAIL for the treatment of PC and VC is limited. The approach appears to be safe and effective, as it provides an adequate lymph node yield while ensuring a minimally morbid postoperative course and a short hospital stay.