Modelado de restauración forestal en sistemas de Dehesa sometidos a herbivoría

Los sistemas forestales de dehesa, presentan en la actualidad un serio problema de regeneración. Por este motivo es necesario diseñar estrategias que faciliten el reclutamiento de plantas jóvenes. En este trabajo desarrollamos un modelo teórico de un sistema con alta presión de herbivoría en el que se simula el efecto de dos medidas de manejo: la repoblación con planta o semilla y la protección de plantones. Se concluye que, según el modelo, resulta más rentable la protección de plantones que la repoblación, pero dado que ambas medidas no son excluyentes en restauración forestal se recomienda una estrategia mixta, siendo la protección de los plantones repoblados muy importante en sistemas con alta presión de herbivoría

Evaluation of Vitamin B12 levels in patients with Type 2 Diabetes Mellitus taking Metformin in the ambulatory care setting

Background: Metformin is the most widely used oral, anti-hyperglycemic medication, prescribed to more than 100 million people across the entire globe (1). Although Metformin has proven beneficial for patients with pre-diabetes, type 2 diabetes, insulin resistance, and PCOS, studies have also shown its use may be associated with vitamin B12 deficiency. Due to a lack of screening criteria, B12 deficiency is likely unrecognized in the ambulatory setting. Our project aimed to improve screening for vitamin B12 deficiency in our clinic amongst patients with diabetes on long-term metformin therapy. Methods: Clinic data was collected from July 1st, 2020, to July 1st, 2022, for a retrospective analysis. After analyzing the initial data, our intervention was initiated as a lecture educating our UTRGV-DHR internal medicine residents on vitamin B12 screening in patients taking Metformin. After the intervention, clinic data was securely collected from January 13th, 2023, to March 1st, 2023, for proper analysis to compare the rates of vitamin B12 screening before and after the intervention. Results: Of 266 patients in our preintervention data, 164 met the exclusion criteria. Of the remaining 102 patients, 18 were appropriately screened for B12 deficiency in the setting of metformin use, equivalent to 17.65% of the total population. Only three patients were found to have B12 deficiency, and all of them received appropriate treatment. After the intervention, the patient´s charts were again evaluated to assess for change in the screening rate. Of the initial 102 patients who met the selection criteria, only 53 were followed up post-intervention. Eight patients were screened for vitamin B12 deficiency, equivalent to 15.09% of the total population. Of these eight patients, two patients did not have a result available on the medical records, four patients had normal B12 levels, and two patients were found to have B12 deficiency. Only 1 of 2 patients received appropriate treatment since the second patient was also lost to follow-up. Conclusion: Our intervention did not result in an increased screening rate for B12 deficiency in the ambulatory setting. Despite our efforts, our project had multiple limitations, including an underserved patient population, elevated test costs, a high rate of patients lost to follow-up, and the impact of COVID-19 in healthcare during 2020 and 2021. Further studies are needed to evaluate if Vitamin B12 should be part of the routine screening of Diabetic patients on Metformin

Kretzoiarctos gen. nov., the Oldest Member of the Giant Panda Clade

The phylogenetic position of the giant panda, Ailuropoda melanoleuca (Carnivora: Ursidae: Ailuropodinae), has been one of the most hotly debated topics by mammalian biologists and paleontologists during the last century. Based on molecular data, it is currently recognized as a true ursid, sister-taxon of the remaining extant bears, from which it would have diverged by the Early Miocene. However, from a paleobiogeographic and chronological perspective, the origin of the giant panda lineage has remained elusive due to the scarcity of the available Miocene fossil record. Until recently, the genus Ailurarctos from the Late Miocene of China (ca. 8–7 mya) was recognized as the oldest undoubted member of the Ailuropodinae, suggesting that the panda lineage might have originated from an Ursavus ancestor. The role of the purported ailuropodine Agriarctos, from the Miocene of Europe, in the origins of this clade has been generally dismissed due to the paucity of the available material. Here, we describe a new ailuropodine genus, Kretzoiarctos gen. nov., based on remains from two Middle Miocene (ca. 12–11 Ma) Spanish localities. A cladistic analysis of fossil and extant members of the Ursoidea confirms the inclusion of the new genus into the Ailuropodinae. Moreover, Kretzoiarctos precedes in time the previously-known, Late Miocene members of the giant panda clade from Eurasia (Agriarctos and Ailurarctos). The former can be therefore considered the oldest recorded member of the giant panda lineage, which has significant implications for understanding the origins of this clade from a paleobiogeographic viewpoint

Rats dying for mice: Modeling the competitor release effect

Introduced vertebrate predators are one of the most important threats to endemic species throughout a range of ecosystems, in particular on islands in biodiversity hot spots. Consequently, the reduction of predator numbers is considered a key conservation action in the management of many native vertebrates vulnerable to predators. It is now established that control attempts may affect non-target species through trophic interactions, but little is known concerning their consequences on competitive relationships. We study a mathematical model mimicking the effects of controlling introduced species in the presence of their competitors. We used two competing rodents to illustrate our study: black rats, Rattus rattus, and mice, Mus musculus. Analyses of the model show that control of only one introduced species logically results in the dramatic increase of the overlooked competitor. We present empirical data that confirm our theoretical predictions. Less intuitively, this process, which we term ‘the competitor release effect’, may also occur when both introduced competitors are simultaneously controlled. In our setting, controlling both predators can promote their coexistence. This occurs as soon as the inferior competitor benefits from the differential effect of the simultaneous control of both competitors, that is, when the indirect positive effect of control (the removal of their competitors) exceeds its direct negative effect (their own removal). Both control levels and target specificity have a direct influence on the extent of this process: counter-intuitively, the stronger and more specific the control, the greater the effect. The theoretical validation of the competitor release effect has important implications in conservation, especially for control management

Lince Ibérico (Lynx pardinus Temminck, 1827) en la Comunidad de Madrid

El Lince Ibérico (Lynx pardinus) es una de las especies de felino más amenazada del planeta, considerándose extinguido en la Comunidad Autónoma de Madrid (C. A. M) desde comienzos del siglo XXI. Sin embargo, las citas en esta región continúan acumulándose. El objetivo del presente estudio ha sido realizar un diagnóstico de la población de L. pardinus en la C. A. M, así como, un modelo de idoneidad de hábitat en esta región

Double specific nested PCR and diagnostic SNP assay for species identification in lynx fecal critical samples

The single lynx species present in the Iberian Peninsula—Lynx pardinus (Temmink, 1827)—is one of the most threatened felines in the world so, any biological indication of its presence is significant. However, it is a very elusive species and physical evidence through direct visualization or camera trapping is difficult to obtain. Genetic noninvasive methods, in particular, molecular scatology, are a reliable alternative to unequivocally identify the presence of a species in a given geographical area. We have developed a highly specific and sensitive molecular method to identify the presence of this critically endangered lynx species from severely deteriorated fecal samples. The method consists in a double specific nested PCR of mitochondrial D-loop sequences and two diagnostic SNPs detected by a multiplex primer extension reaction