Phase synchronization between culture and climate forcing.

Over the history of humankind, cultural innovations have helped improve survival and adaptation to environmental stress. This has led to an overall increase in human population size, which in turn further contributed to cumulative cultural learning. During the Anthropocene, or arguably even earlier, this positive sociodemographic feedback has caused a strong decline in important resources that, coupled with projected future transgression of planetary boundaries, may potentially reverse the long-term trend in population growth. Here, we present a simple consumer/resource model that captures the coupled dynamics of stochastic cultural learning and transmission, population growth and resource depletion in a changing environment. The idealized stochastic mathematical model simulates boom/bust cycles between low-population subsistence, high-density resource exploitation and subsequent population decline. For slow resource recovery time scales and in the absence of climate forcing, the model predicts a long-term global population collapse. Including a simplified periodic climate forcing, we find that cultural innovation and population growth can couple with climatic forcing via nonlinear phase synchronization. We discuss the relevance of this finding in the context of cultural innovation, the anthropological record and long-term future resilience of our own predatory species.

An Unusual Bacterial Etiology of Fournier's Gangrene in an Immunocompetent Patient.

Fournier's gangrene (FG) is necrotizing fasciitis that affects the penis, scrotum, or perineum. Males are more likely to get affected by this disease. The most common predisposing risk factors are diabetes, alcoholism, hypertension, smoking, and immunosuppressive disorders. FG is a polymicrobial infection caused by both aerobic and anaerobic bacteria. The most common aerobic organisms are Escherichia coli, Klebsiella, Proteus, Staphylococcus, and Streptococcus. The most common anaerobic organisms are Bacteroides, Clostridium, and Peptostreptococcus. The disease carries high mortality and morbidity, so timely diagnosis and treatment are of utmost importance. Here, we report a case of a 61-year-old male with a medical history significant for benign prostatic hyperplasia (BPH), who presented to our hospital with fever, watery diarrhea, and painful swelling of the scrotum and penis. The patient was started on piperacillin-tazobactam, vancomycin, and clindamycin. A computed tomography scan of the pelvis showed prostatic enlargement, edema of the penis and scrotum, and air collection within the corpus cavernosum. The patient underwent multiple surgical debridements of the glans penis. Patient wound cultures were positive for Streptococcus anginosus, Actinomyces turicensis, and Peptoniphilus harei. As mentioned earlier, FG is common in diabetic and immunocompromised patients, and infection is usually polymicrobial. Our patient was immunocompetent and his cultures grew atypical organisms.