Anesthetic block of the dorsal penile nerve inhibits vibratory-Induced ejaculation in men with spinal cord injuries

Objectives. We investigated which nerve pathways are necessary to achieve ejaculation using penile vibratory stimulation (PVS) in men with spinal cord injury (SCI). Methods. Eight men with SCI were selected based on the presence of a bulbocavernosus reflex (BCR) and consistent antegrade ejaculation with PVS. Level of injury was cervical (4), upper thoracic (4), and lower thoracic (1). Mean age was 30.4 years (range 22 to 38). Usual responses to PVS included autonomic dysreflexia (4), erection (4), and consistent somatic responses such as abdominal contractions (8). Local anesthesia of the dorsal penile nerves (penile block) was achieved using 1% plain lidocaine injection. Effective penile block was confirmed by loss of the BCR. Two PVS ejaculation trials were performed: one trial during the penile block and one trial when the penile block had worn off. In 4 subjects, the bladder contents were analyzed for retrograde ejaculation. Results. With the penile block, ejaculation was inhibited in 100% of the subjects. None of the bladder washings demonstrated sperm, indicating absence of retrograde ejaculation. None of the subjects exhibited their usual erectile response, somatic responses, or signs of autonomic dysreflexia. After the penile block wore off, PVS induced ejaculation in all subjects. If subjects usually had erection, somatic responses, or signs of autonomic dysreflexia, these also returned. Conclusions. Our data suggest that ejaculatory response to PVS in SCI men requires the presence of intact dorsal penile nerves

Brown‐Colored Semen in Men With Spinal Cord Injury

The interesting condition of brown‐colored semen has often been observed during assisted ejaculation of men with spinal cord injury (SCI). This condition has not been reported in the literature, and its cause is unknown. To investigate this condition, the present study examined the incidence and quality of brown semen and its relationship to level of SCI, time since SCI, number of successive ejaculations, ejaculation frequency, and ejaculation method in a total of 664 semen specimens from 162 SCI men. In addition, a microscopic evaluation was performed on brown semen specimens from SCI men, not‐brown specimens from SCI men, and normally colored specimens from normal men. The results showed that 27% of SCI subjects had brown semen on at least one ejaculation. There was no difference between men producing and men not producing brown semen in age, level of injury, or years postinjury. The duration of anejaculation, number of successive ejaculations, and frequency of ejaculation were not associated with occurrence of brown semen. Sperm concentration and sperm motility were not significantly different in brown and not‐brown specimens. Specimens from subjects who produced brown semen had similar pH but lower volume than specimens from subjects who did not produce brown semen. Brown semen had a thin consistency more often than not‐brown semen. Brown specimens contained intact red blood cells (RBCs) and/or heme pigment more often than not‐brown specimens; however, one half and one third of the specimens, respectively, contained neither RBCs nor heme pigment. The cause of brown semen is unknown but may relate to seminal‐vesicle dysfunction

Moisture-driven divergence in mineral-associated soil carbon persistence

Mineral stabilization of soil organic matter is an important regulator of the global carbon (C) cycle. However, the vulnerability of mineral-stabilized organic matter (OM) to climate change is currently unknown. We examined soil profiles from 34 sites across the conterminous USA to investigate how the abundance and persistence of mineral-associated organic C varied with climate at the continental scale. Using a novel combination of radiocarbon and molecular composition measurements, we show that the relationship between the abundance and persistence of mineral-associated organic matter (MAOM) appears to be driven by moisture availability. In wetter climates where precipitation exceeds evapotranspiration, excess moisture leads to deeper and more prolonged periods of wetness, creating conditions which favor greater root abundance and also allow for greater diffusion and interaction of inputs with MAOM. In these humid soils, mineral- associated soil organic C concentration and persistence are strongly linked, whereas this relationship is absent in drier climates. In arid soils, root abundance is lower, and interaction of inputs with mineral surfaces is limited by shallower and briefer periods of moisture, resulting in a disconnect between concentration and persistence. Data suggest a tipping point in the cycling of mineral-associated C at a climate threshold where precipitation equals evaporation. As climate patterns shift, our findings emphasize that divergence in the mechanisms of OM persistence associated with historical climate legacies need to be considered in process-based models

Biological and Environmental Research Exascale Requirements Review

The article of record as published may be found at http://dx.doi.org/10.2172/1375720An Office of Science review sponsored jointly by Advanced Scientific Computing Research and Biological and Environmental Research, March 28-31, 2016, Rockville, MarylandUnderstanding the fundamentals of genomic systems or the processes governing impactful weather patterns are examples of the types of simulation and modeling performed on the most advanced computing resources in America. High-performance computing and computational science together provide a necessary platform for the mission science conducted by the Biological and Environmental Research (BER) office at the U.S. Department of Energy (DOE). This report reviews BER’s computing needs and their importance for solving some of the toughest problems in BER’s portfolio. BER’s impact on science has been transformative. Mapping the human genome, including the U.S.-supported international Human Genome Project that DOE began in 1987, initiated the era of modern biotechnology and genomics-based systems biology. And since the 1950s, BER has been a core contributor to atmospheric, environmental, and climate science research, beginning with atmospheric circulation studies that were the forerunners of modern Earth system models (ESMs) and by pioneering the implementation of climate codes onto high-performance computers. See http://exascaleage.org/ber/ for more information.USDOE Office of Science (SC), Advanced Scientific Computing Research (SC-21)USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23