Long-distance swimming by African lions in Uganda.

Earth's most imperiled and iconic wildlife are facing tough decisions under increasing human pressure and limited resources. Swimming across rivers and water bodies filled with high densities of predators may be one such example. In African lions Panthera leo, previous water crossings (recorded in the peer-reviewed and gray literature, on film, and found using Google Search, and YouTube) have recorded distances ranging from <10 to 100 m, with some resulting in mortality by Nile Crocodiles Crocodylis niloticus. However, we observed a coalition of male lions swimming >1 km across Uganda's Kazinga channel located in the Queen Elizabeth National Park six times, and recorded this behavior on film on February 1st 2024. We speculate that three factors could be driving these lions to take long-distance swims with a high density of crocodiles and hippos Hippopotamus amphibius, namely (1) the lack of lionesses in this ecosystem, (2) intraspecific fights over territory with other male coalitions, and (3) the only other land connection giving lions access to the peninsula is a small road bridge with a strong human presence.

Deforestation in Colombian protected areas increased during post-conflict periods.

Protected areas (PAs) are a foundational and essential strategy for reducing biodiversity loss. However, many PAs around the world exist on paper only; thus, while logging and habitat conversion may be banned in these areas, illegal activities often continue to cause alarming habitat destruction. In such cases, the presence of armed conflict may ultimately prevent incursions to a greater extent than the absence of conflict. Although there are several reports of habitat destruction following cessation of conflict, there has never been a systematic and quantitative "before-and-after-conflict" analysis of a large sample of PAs and surrounding areas. Here we report the results of such a study in Colombia, using an open-access global forest change dataset. By analysing 39 PAs over three years before and after Colombia's peace agreement with the Revolutionary Armed Forces of Colombia (FARC), we found a dramatic and highly significant increase in the deforestation rate for the majority of these areas and their buffer zones. We discuss the reasons behind such findings from the Colombian case, and debate some general conservation lessons applicable to other countries undergoing post-conflict transitions.

Soft systems thinking and social learning for adaptive management.

The success of adaptive management in conservation has been questioned and the objective-based management paradigm on which it is based has been heavily criticized. Soft systems thinking and social-learning theory expose errors in the assumption that complex systems can be dispassionately managed by objective observers and highlight the fact that conservation is a social process in which objectives are contested and learning is context dependent. We used these insights to rethink adaptive management in a way that focuses on the social processes involved in management and decision making. Our approach to adaptive management is based on the following assumptions: action toward a common goal is an emergent property of complex social relationships; the introduction of new knowledge, alternative values, and new ways of understanding the world can become a stimulating force for learning, creativity, and change; learning is contextual and is fundamentally about practice; and defining the goal to be addressed is continuous and in principle never ends. We believe five key activities are crucial to defining the goal that is to be addressed in an adaptive-management context and to determining the objectives that are desirable and feasible to the participants: situate the problem in its social and ecological context; raise awareness about alternative views of a problem and encourage enquiry and deconstruction of frames of reference; undertake collaborative actions; and reflect on learning.

Ursolic acid: an anti-tumorigenic and chemopreventive activity. Minireview.

Ursolic acid, UA, as a pentacyclic triterpene is of interest to scientists in the area of oncology because of its cytotoxicity, induction of differentiation, anti-mutagenic, antiviral and anti-invasive activities. UA is capable of inducing apoptosis in tumor cells on one side and to prevent malignant transformation of normal cells on the other side. It also interferes with numerous enzymes, including the ones serving directly to DNA synthesis. The aim of this review is to summarize reports on UA biological properties and to show its main anti-tumor effects and chemopreventive properties in normal cells.

ET(B) receptor activates adenylyl cyclase via a c-PLA(2)-dependent mechanism: a novel counterregulatory mechanism of ET-induced contraction in airway smooth muscle.

Endothelin-1 (ET-1) contracted the rabbit tracheal smooth muscle (RTSM), yielding a bell-shaped tension-concentration curve. Moreover, ET-1 induced concentration- and time-dependent increases in cAMP concentrations in RTSM (EC(50), 58 nM; t(1/2), 2.4 min). Pretreatment with the AC inhibitors, SQ-22536, or 2'-5'-dideoxyadenosine, enhanced contraction to ET-1 and converted its bell-shaped tension curve into a sigmoidal one, but left contraction to carbachol and KCl unaltered. The potent ET(B)-receptor agonists, ET-3 or sarafotoxin-c, mimicked ET-1's effects on cAMP levels (EC(50) values 55 and 50 nM). Further, cAMP formation by ETs was inhibited by BQ-788 (selective ET(B) receptor blocker; IC(50), 8 nM), but not by BQ-610 (selective ET(A) receptor blocker). Removal of the epithelium did not prevent ET-induced increases in cAMP levels. Unlike isoproterenol, ETs failed to activate AC in membrane fractions from RTSM. In intact RTSM, the c-PLA(2) inhibitor, AACOCF3, and the cyclooxygenase inhibitor, indomethacin, blocked ET-induced increases in cAMP levels. These findings reveal a novel, nonepithelial, c-PLA(2)-mediated, regulatory mechanism downstream from ET(B) receptors.

Lipid management among coronary artery disease patients with diabetes mellitus or advanced age.

Aggressive lipid management is likely beneficial for coronary artery disease patients with diabetes mellitus or of advanced age. Nevertheless, a study of a large national sample of patients seen in ambulatory medical practices suggests pharmacologic undertreatment in these high-risk groups.

Performance assessment model for guideline-recommended pharmacotherapy in the secondary prevention of coronary artery disease and treatment of left ventricular dysfunction.

The Agency for Health Care Policy and Research, the National Heart Lung and Blood Institute of the National Institutes of Health, the American Heart Association, and the American College of Cardiology have all developed guidelines for improving the care of patients with cardiovascular disease. The guidelines include recommendations for intensive lipid-lowering therapy in patients with coronary artery disease (CAD) and angiotensin-converting enzyme (ACE) inhibitors in those patients with symptomatic heart failure and asymptomatic left ventricular dysfunction. Despite clinical trial evidence and consensus that these therapies improve survival in high-risk patients, data suggest that there is wide variation in the delivery of guideline-based care. To investigate whether evidence-based assessment of provider practice patterns can impact the delivery of quality cost-effective care, Merck and Company, in conjunction with leading cardiology group practices, the University of North Carolina at Chapel Hill, and Medical Review of North Carolina developed an ambulatory medical record abstraction study. This quality assurance initiative was conducted at practices beginning in the spring of 1996 and continues. Medical records and administrative claims of patients with ischemic heart disease or heart failure were abstracted by a healthcare consulting organization to maintain patient and physician confidentiality. As of mid-July 1997, 626 group practices had completed the medical record abstraction process, with > 1,136 practices participating at some stage of the project; >6,000 physicians participated in the project and >270,000 patients charts were abstracted. Analysis of these data will provide insight and benchmark patterns of care in the pharmacologic management of heart failure and CAD. This project represents a unique collaboration between a pharmaceutical company, an academic institution, a Peer Review Organization, and practicing physicians, to support evidence-based best medical practices.

Acceleration of iterative image restoration algorithms.

A new technique for the acceleration of iterative image restoration algorithms is proposed. The method is based on the principles of vector extrapolation and does not require the minimization of a cost function. The algorithm is derived and its performance illustrated with Richardson-Lucy (R-L) and maximum entropy (ME) deconvolution algorithms and the Gerchberg-Saxton magnitude and phase retrieval algorithms. Considerable reduction in restoration times is achieved with little image distortion or computational overhead per iteration. The speedup achieved is shown to increase with the number of iterations performed and is easily adapted to suit different algorithms. An example R-L restoration achieves an average speedup of 40 times after 250 iterations and an ME method 20 times after only 50 iterations. An expression for estimating the acceleration factor is derived and confirmed experimentally. Comparisons with other acceleration techniques in the literature reveal significant improvements in speed and stability.

Lipid mediators in oxygen-induced airway remodeling and hyperresponsiveness in newborn rats.

We examined whether lipid mediators have a causal role in neonatal hyperoxia-induced lung damage, specifically, airway remodeling and hyperresponsiveness. Newborn rat pups were exposed to hyperoxia (> 95% O2 from Days 4 to 14 and 65% from Days 14 to 32) or normoxia. The 5-lipoxygenase inhibitor, LTD4 receptor antagonist, and inhibitor of platelet-activating factor synthesis, Wy-50,295 (30 mg/kg), or vehicle was administered daily from Days 3 to 32. Oxygen exposure significantly increased (p < 0.05) the production of one potential lipid mediator group, peptido-LTs, from explanted lung slices and large airways from 2-wk-old rat pups. At 4 wk, only the large airway tissue output showed significant elevation because of oxygen exposure. At both ages, Wy-50,295 significantly decreased (p < 0.05) the production of peptido-LTs in the lung and large airways of oxygen-exposed pups. Pulmonary function and airway wall morphometry were studied in 5-wk-old rat pups 2 to 3 d after oxygen exposure and drug administration ceased. The resistance change in response to methacholine (0 to 20 microg/kg body weight given intravenously) was greater (p < 0.02) in oxygen-exposed animals. Oxygen exposure caused significant (60% increase) smooth muscle thickening (p < 0.05). Wy-50,295 prevented the oxygen-induced airway hyperresponsiveness and smooth muscle thickening. We conclude that chronic hyperoxic exposure causes an increase in pulmonary production of at least one lipid mediator, peptido-LTs, from newborn rats and that this is associated with airway smooth muscle layer thickening and, consequently, airway hyperresponsiveness.

Radiation properties of a miniature X-ray device for radiosurgery.

An alternative technology for performing interstitial intracranial radiosurgery is presented. Treatments are performed intraoperatively using a stereotactically mounted, miniature X-ray device. A concentrated, spherical pattern of X-rays is generated about the tip of a needle-like probe, which is inserted into the site of the lesion allowing the absorbed dose to healthy tissue to be minimized. A description of the device is given and results of investigations into the operating characteristics discussed.

The resistant frozen shoulder. Manipulation versus arthroscopic release.

Frozen shoulder is often a self-limited disease, but approximately 10% of patients have long-term problems. Arthroscopy was done in 40 patients with persistent pain, stiffness, and functional loss for at least 1 year without improvement despite conventional treatment. In the first 20 patients, manipulation was done with an arthroscopy before and afterward; in the second 20 patients, the contracted structures were divided through arthroscopy. This was a prospective cohort study; 2 patients were not available for followup. The arthroscopic division procedure was done in 4 sequential steps: (1) resection of the inflammatory synovium in the interval area between the subscapularis and supraspinatus; (2) progressive division of the anterior superior glenohumeral ligament and anterior capsule; (3) division of the subscapularis tendon but not muscle; and (4) division of the inferior capsule. The results were assessed independently on the basis of pain, stiffness, and function. The followup varied from 2 to 5 years after intervention. Patients treated with arthroscopy and manipulation did as well as the patients treated with arthroscopic division for restoration of range of movement. However, the patients in the arthroscopic division group had significantly better pain relief and restoration of function. Fifteen of 20 patients treated with arthroscopic division had an excellent result compared with 7 of 18 patients treated with arthroscopy and manipulation. Patients with diabetes did worse initially, but the outcome was similar to patients without diabetes. Patients with diabetes in particular may benefit from early intervention.

Pasteurella multocida septicemia and subsequent Pasteurella dagmatis septicemia in a diabetic patient.

Pasteurella species may cause zoonotic infections of humans. Serious systemic infections with these organisms are unusual, but they may occur in individuals with predisposing underlying illnesses. Occurrences of bacteremia due to P. multocida are infrequent, and P. dagmatis bacteremia is even rarer. We report independent occurrences of P. multocida and P. dagmatis septicemia in the same diabetic patient after contact with two pet dogs. We review the history of Pasteurella species and discuss the biochemical and clinical features of its association with zoonosis.