Mixed intoxication with Aconitum nappellans (monkshood) and Digitalis grandiflora (large yellow foxglove)

Intoxications are frequent and relevant medical problems in emergency units.

Effects of hibernation on bone in yellow-bellied marmots

Disuse osteoporosis is a problem for people with spinal cord injury or stroke, patients confined to bed rest, and astronauts exposed to microgravity. Unlike most mammals however, bears have been shown to prevent bone loss during hibernation, a seasonal period of disuse. Similarly, studies in ground squirrels indicate preservation of whole bone strength during hibernation, though evidence suggests there may be some increased osteocytic osteolysis. Uncovering the mechanism by which these animals prevent bone loss during hibernation could lead to an improved treatment for osteoporosis in humans. Marmots are a good animal model for these studies because they are small enough to easily house in an animal facility yet still utilize intracortical remodeling like humans and bears, and unlike smaller rodents like squirrels. Marmots preserve bone mechanical and microstructural properties during hibernation. Bone mechanical and geometrical properties are not diminished in post-hibernation samples compared to pre-hibernation samples. Mineral content, measured by ash fraction, was higher in post-hibernation samples (p = 0.0003). Haversian porosity as well as remodeling cavity density were not different (p > 0.38) between pre- and post-hibernation samples. Similarly, average lacunar area, lacunar density, and lacunar porosity were all lower (p < 0.0001) in post-hibernation samples. Trabecular thickness was larger in posthibernation samples (p = 0.0058). Bone volume fraction was not different between groups, but approached significance (p = 0.0725). Further studies in marmots and other hibernators could help uncover the mechanism that allows hibernators to prevent disuse osteoporosis during hibernation.

Immunogenicity and safety of yellow fever vaccination for 102 HIV-infected patients

BACKGROUND: Yellow fever vaccine (17DV) has been investigated incompletely in human immunodeficiency virus (HIV)-infected patients, and adequate immunogenicity and safety are of concern in this population. METHODS: In the Swiss HIV Cohort Study, we identified 102 patients who received 17DV while they were HIV infected. We analyzed neutralization titers (NTs) after 17DV administration using the plaque reduction neutralization test. NTs of 1:>or=10 were defined as reactive, and those of 1:<10 were defined as nonreactive, which was considered to be nonprotective. The results were compared with data for HIV-uninfected individuals. Serious adverse events were defined as hospitalization or death within 6 weeks after receipt of 17DV. RESULTS: At the time of 17DV administration, the median CD4 cell count was 537 cells/mm(3) (range, 11-1730 cells/mm(3)), and the HIV RNA level was undetectable in 41 of 102 HIV-infected patients. During the first year after vaccination, fewer HIV-infected patients (65 [83%] of 78; P = .01) than HIV-uninfected patients revealed reactive NTs, and their NTs were significantly lower (P < .001) than in HIV-uninfected individuals. Eleven patients with initially reactive NTs lost these reactive NTs

Book Review of “Indigenous Social Work around the World. Towards Culturally Relevant Education and Practice”, 2008, edited by Mel Gray, John Coates and Michael Yellow Bird

One could be seduced into a critique of this volume that focuses on its potential to overstate the momentum for a shift in Western social work ideology when faced with the conundrum of cultural difference. One could posit that the discussion is too broad, the topics covered too numerous, the opportunity for detail missed, the urgency of the messages unnecessarily exaggerated, the “proof” not beyond anecdote and so forth. I reject this temptation to conform to the dominant professional dynamic most emphatically and offer that what Gray, Coates and Yellow Bird have presented to the social work field in this volume is the first tangible step towards an alternative paradigm for an occupation afflicted with unsustainable hypocrisy and thus at the brink of irrelevancy.

High-sensitivity rod photoreceptor input to the blue-yellow color opponent pathway in macaque retina.

Small bistratified cells (SBCs) in the primate retina carry a major blue-yellow opponent signal to the brain. We found that SBCs also carry signals from rod photoreceptors, with the same sign as S cone input. SBCs exhibited robust responses under low scotopic conditions. Physiological and anatomical experiments indicated that this rod input arose from the AII amacrine cell-mediated rod pathway. Rod and cone signals were both present in SBCs at mesopic light levels. These findings have three implications. First, more retinal circuits may multiplex rod and cone signals than were previously thought to, efficiently exploiting the limited number of optic nerve fibers. Second, signals from AII amacrine cells may diverge to most or all of the approximately 20 retinal ganglion cell types in the peripheral primate retina. Third, rod input to SBCs may be the substrate for behavioral biases toward perception of blue at mesopic light levels.

Positive effect of the yellow morph on female reproductive success in the flower colour polymorphic Iris lutescens (Iridaceae), a deceptive species

The deceptive Iris lutescens (Iridaceae) shows a heritable and striking flower colour polymorphism, with both yellow- and purple-flowered individuals growing sympatrically. Deceptive species with flower colour polymorphism are mainly described in the family Orchidaceae and rarely found in other families. To explain the maintenance of flower colour polymorphism in I.lutescens, we investigated female reproductive success in natural populations of southern France, at both population and local scales (within populations). Female reproductive success was positively correlated with yellow morph frequency, at both the population scale and the local scale. Therefore, we failed to observe negative frequency-dependent selection (NFDS), a mechanism commonly invoked to explain flower colour polymorphism in deceptive plant species. Flower size and local flower density could also affect female reproductive success in natural populations. Pollinator behaviour could explain the positive effect of the yellow morph, and our results suggest that flower colour polymorphism might not persist in I.lutescens, but alternative explanations not linked to pollinator behaviour are discussed. In particular, NFDS, although an appealingly simple explanation previously demonstrated in orchids, may not always contribute to maintaining flower colour polymorphism, even in deceptive species.

Morphological alterations in the liver of yellow perch (Perca flavescens) from a biological mercury hotspot

Mercury (Hg) contamination is a global issue due to its anthropogenic release, long-range transport, and deposition in remote areas. In Kejimkujik National Park and National Historic Site, Nova Scotia, Canada, high concentrations of total mercury (THg) were found in tissues of yellow perch (Perca flavescens). The aim of this study was to evaluate a possible relationship between THg concentrations and the morphology of perch liver as a main site of metal storage and toxicity. Yellow perch were sampled from five lakes known to contain fish representing a wide range in Hg concentrations in fall 2013. The ultrastructure of hepatocytes and the distribution of Hg within the liver parenchyma were analyzed by transmission electron microscopy (TEM) and electron energy loss spectrometry (EELS). The relative area of macrophage aggregates (MAs) in the liver was determined using image analysis software and fluorescence microscopy. No relation between general health indicators (Fulton's condition index) and THg was observed. In line with this, TEM examination of the liver ultrastructure revealed no prominent pathologies related to THg accumulation. However, a morphological parameter that appeared to increase with muscle THg was the relative area of MAs in the liver. The hepatic lysosomes appeared to be enlarged in samples with the highest THg concentrations. Interestingly, EELS analysis revealed that the MAs and hepatic lysosomes contained Hg.

Yellow laser light generation by frequency doubling of the output from a master oscillator fiber power amplifier system

We present a power-scalable approach for yellow laser-light generation based on standard Ytterbium (Yb) doped fibers. To force the cavity to lase at 1154 nm, far above the gain-maximum, measures must be taken to fulfill lasing condition and to suppress competing amplified spontaneous emission (ASE) in the high-gain region. To prove the principle we built a fiber-laser cavity and a fiber-amplifier both at 1154 nm. In between cavity and amplifier we suppressed the ASE by 70 dB using a fiber Bragg grating (FBG) based filter. Finally we demonstrated efficient single pass frequency doubling to 577 nm with a periodically poled lithium niobate crystal (PPLN). With our linearly polarized 1154 nm master oscillator power fiber amplifier (MOFA) system we achieved slope efficiencies of more than 15 % inside the cavity and 24 % with the fiber-amplifier. The frequency doubling followed the predicted optimal efficiency achievable with a PPLN crystal. So far we generated 1.5 W at 1154nm and 90 mW at 577 nm. Our MOFA approach for generation of 1154 nm laser radiation is power-scalable by using multi-stage amplifiers and large mode-area fibers and is therefore very promising for building a high power yellow laser-light source of several tens of Watt.

Dr. William Gorgas and his style of management against yellow fever during the construction of the Panama Canal: A historical case study

This study describes the style of management of Dr. William Gorgas as he led the public health effort to reduce diseases to a level that permitted the completion of the Panama Canal construction. Initially, Gorgas was skeptical of the mosquito vector theory. He fully accepted this theory after participating in Walter Reed’s massive cleanup of Havana, Cuba during the Spanish American War of 1898. During 1905 to 1914, Gorgas was selected to lead the sanitary effort during the construction of the Panama Canal. The lessons learned from this historical case study provide public health administrators with guidance to effectively lead current and future infectious diseases threats. Understanding styles of management within the context of disease control is essential in tackling epidemics like yellow fever and other infectious diseases. ^

TRANSOVARIAL TRANSMISSION OF YELLOW FEVER VIRUS BY A SYLVATIC VECTOR, HAEMAGOGUS EQUINUS (THEOBALD)

The potential of a sylvatic vector to act as reservoir of yellow fever virus was assessed in Haemagogus equinus (Theobald). Mosquitoes from the Maje'75 laboratory colony and a Panamanian human isolated strain of yellow fever virus were used. Female mosquitoes infected with yellow fever virus had a minimum transovarial transmission rate of 1:5745. This is the first time transovarial transmission of yellow fever virus has been demonstrated in a New World sylvatic vector. Transovarial transmission of yellow fever virus in this sylvatic mosquito species may be an alternative mechanism for biological survival of the virus during adverse periods or in the absence of susceptible vertebrate hosts. ^

Contemporary genetic, historical genetic and morphological data sets for the Yellow-tufted Honeyeater Lichenostomus melanops

Understanding the evolutionary history of threatened populations can improve their conservation management. Re-establishment of past but recent gene flow could re-invigorate threatened populations and replenish genetic diversity, necessary for population persistence. One of the four nominal subspecies of the common yellow-tufted honeyeater, Lichenostomus melanops cassidix, is critically endangered despite substantial conservation efforts over 55 years. Using a combination of morphometric, genetic and modelling approaches we tested for its evolutionary distinctiveness and conservation merit. We confirmed that cassidix has at least one morphometric distinction. It also differs genetically from the other subspecies in allele frequencies but not phylogenetically, implying that its evolution was recent. Modelling historical distribution supported the lack of vicariance and suggested a possibility of gene flow among subspecies at least since the late Pleistocene. Multi-locus coalescent analyses indicated that cassidix diverged from its common ancestor with neighbouring subspecies gippslandicus sometime from the mid-Pleistocene to the Holocene, and that it has the smallest historical effective population size of all subspecies. It appears that cassidix diverged from its ancestor with gippslandicus through a combination of drift and local selection. From patterns of genetic subdivision on two spatial scales and morphological variation we concluded that cassidix, gippslandicus and (melanops + meltoni) are diagnosable as subspecies. Low genetic diversity and effective population size of cassidix may translate to low genetic fitness and evolutionary potential, thus managed gene flow from gippslandicus is recommended for its recovery.