抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Secret History: Return of the Black Death Channel 4, 7-8pm In 1348 the Black Death swept through London, killing people within days of the appearance of their first symptoms. Exactly how many died, and why, has long been a mystery. This Secret History documentary follows experts as they pick through the evidence and reveal why the plague killed on such a scale. And they ask, what might be coming next?

Medscape

‡We describe the use of singular value decomposition in transforming genome-wide expression data from genes 3 arrays space to reduced diagonalized ‘‘eigengenes’’ 3 ‘‘eigenarrays’’ space, where the eigengenes (or eigenarrays) are unique orthonormal superpositions of the genes (or arrays). Normalizing the data by filtering out the eigengenes (and eigenarrays) that are inferred to represent noise or experimental artifacts enables meaningful comparison of the expression of different genes across different arrays in different experiments. Sorting the data according to the eigengenes and eigenarrays gives a global picture of the dynamics of gene expression, in which individual genes and arrays appear to be classified into groups of similar regulation and function, or similar cellular state and biological phenotype, respectively. After normalization and sorting, the significant eigengenes and eigenarrays can be associated with observed genome-wide effects of regulators, or with measured samples, in which these regulators are overactive or underactive, respectively.

Singular Value Decomposition for Genome-Wide Expression Data Processing and Modeling

Conscious and unconscious perception: An approach to the relations between phenomenal experience and perceptual processes

Optogenetics has revolutionized the experimental interrogation of neural circuits and holds promise for the treatment of neurological disorders It is limited, however, because visible light cannot penetrate deep inside brain tissue Upconversion nanoparticles (UCNPs) absorb tissue-penetrating near-infrared (NIR) light and emit wavelength-specific visible light Here, we demonstrate that molecularly tailored UCNPs can serve as optogenetic actuators of transcranial NIR light to stimulate deep brain neurons Transcranial NIR UCNP-mediated optogenetics evoked dopamine release from genetically tagged neurons in the ventral tegmental area, induced brain oscillations through activation of inhibitory neurons in the medial septum, silenced seizure by inhibition of hippocampal excitatory cells, and triggered memory recall UCNP technology will enable less-invasive optical neuronal activity manipulation with the potential for remote therapy

http://science.sciencemag.org/content/sci/359/6376/679.full.pdf

Near-infrared deep brain stimulation via upconversion nanoparticle–mediated optogenetics

Improved methods of noninvasively modulating human brain function are needed. Here we probed the influence of transcranial focused ultrasound (tFUS) targeted to the human primary somatosensory cortex (S1) on sensory-evoked brain activity and sensory discrimination abilities. The lateral and axial spatial resolution of the tFUS beam implemented were 4.9 mm and 18 mm, respectively. Electroencephalographic recordings showed that tFUS significantly attenuated the amplitudes of somatosensory evoked potentials elicited by median nerve stimulation. We also found that tFUS significantly modulated the spectral content of sensory-evoked brain oscillations. The changes produced by tFUS on sensory-evoked brain activity were abolished when the acoustic beam was focused 1 cm anterior or posterior to S1. Behavioral investigations showed that tFUS targeted to S1 enhanced performance on sensory discrimination tasks without affecting task attention or response bias. We conclude that tFUS can be used to focally modulate human cortical function.

Transcranial focused ultrasound modulates the activity of primary somatosensory cortex in humans

Antibasal ganglia antibodies (ABGA) are associated with Sydenham's chorea and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections. We present 10 patients with acute disseminated encephalomyelitis (ADEM) associated with Group A beta hemolytic streptococcal infection. The clinical phenotype was novel, with 50% having a dystonic extrapyramidal movement disorder, and 70% a behavioral syndrome. None of the patients had rheumatic fever or Sydenham's chorea. Enzyme-linked immunosorbent assay, Western immunoblotting, and immunohistochemistry were used to detect ABGA. Neurological (n = 40) and streptococcal (n = 40) controls were used for comparison. Enzyme-linked immunosorbent assay results showed significantly elevated ABGA in the patients with poststreptococcal ADEM. Western immunoblotting demonstrated ABGA reactivity to three dominant protein bands of 60, 67, or 80 kDa; a finding not reproduced in controls. Fluorescent immunohistochemistry demonstrated specific binding to large striatal neurones, which was not seen in controls. Streptococcal serology was also significantly elevated in the poststreptococcal ADEM group compared with neurological controls. Magnetic resonance imaging studies showed hyperintense basal ganglia in 80% of patients with poststreptococcal ADEM, compared to 18% of patients with nonstreptococcal ADEM. These findings support a new subgroup of postinfectious autoimmune inflammatory disorders associated with Group A beta hemolytic streptococcus, abnormal basal ganglia imaging, and elevated ABGA.

Poststreptococcal acute disseminated encephalomyelitis with basal ganglia involvement and auto-reactive antibasal ganglia antibodies.

Great Boiling Spring is a large, circumneutral, geothermal spring in the US Great Basin. Twelve samples were collected from water and four different sediment sites on four different dates. Microbial community composition and diversity were assessed by PCR amplification of a portion of the small subunit rRNA gene using a universal primer set followed by pyrosequencing of the V8 region. Analysis of 164 178 quality-filtered pyrotags clearly distinguished sediment and water microbial communities. Water communities were extremely uneven and dominated by the bacterium Thermocrinis. Sediment microbial communities grouped according to temperature and sampling location, with a strong, negative, linear relationship between temperature and richness at all taxonomic levels. Two sediment locations, Site A (87–80 °C) and Site B (79 °C), were predominantly composed of single phylotypes of the bacterial lineage GAL35 (p=36.1%), Aeropyrum (p=16.6%), the archaeal lineage pSL4 (p=15.9%), the archaeal lineage NAG1 (p=10.6%) and Thermocrinis (p=7.6%). The ammonia-oxidizing archaeon ‘Candidatus Nitrosocaldus’ was relatively abundant in all sediment samples <82 °C (p=9.51%), delineating the upper temperature limit for chemolithotrophic ammonia oxidation in this spring. This study underscores the distinctness of water and sediment communities in GBS and the importance of temperature in driving microbial diversity, composition and, ultimately, the functioning of biogeochemical cycles.

/pdf/sediment-microbial-communities-in-great-boiling-spring-are-le7hjcux9i.pdf

Sediment microbial communities in Great Boiling Spring are controlled by temperature and distinct from water communities.

We examined the prevalence of vitamin D deficiency and insufficiency in children attending our tuberculosis (TB) clinic during a 2-year period. Sixty-four patients were included with active TB (n = 26) or latent TB infection (n = 38). Eighty-six percent (n = 55) were either vitamin D deficient (serum 25-hydroxyvitamin D <20 nmol/L) or insufficient (serum 25-hydroxyvitamin D <75 nmol/L). Only 1 child with active TB was vitamin D replete.

Amanda J. Williams

Papers

Transcranial focused ultrasound modulates the activity of primary somatosensory cortex in humans

Poststreptococcal acute disseminated encephalomyelitis with basal ganglia involvement and auto-reactive antibasal ganglia antibodies.

Sediment microbial communities in Great Boiling Spring are controlled by temperature and distinct from water communities.

Vitamin D deficiency and insufficiency in children with tuberculosis.

Biological Soil Crusts in the Mojave Desert, USA: Micromorphology and Pedogenesis