Nest Morphogenesis and Population Ecology of Two Species of Formica

Two species of thatching ants (Formica obscuripes and F. oreas comptula) are common to the ecotone and woodland habitats of the Forest River Biology Station near Inkster, Grand Forks County, North Dakota. The general ecology for each species was determined with emphasis on mound morphogenesis, colony-founding and population characteristics. For each species the following samples and data were collected: random samples of each population, thatch sample, external and internal mound measurements, and field maps of distribution patterns. The morphogenesis of F. obscurlpes mounds was found to follow a predictable pattern with three well defined but transitional nest forms: (1) Stage I, characterized by a thatched dome without excavation, (2) Stage IT, characterized by a raised, thatched dome, earthen embankment and an excavated pocket containing thatch, and (3) Stage III, characterized by a depressed dome of deteriorating thatch, producing a crater-like effect. Random samples of workers taken from selected mounds in various stages of growth indicated that the ratio of minors to majors increased with growth and aging of colonies. Minors made up a larger percentage of the sample taken from Stage III mounds as compared to Stages I and II. Annual measurements of mounds over a the growth of mounds and population seven-year period showed followed a predictable growth curve. Stage I mounds were typically geometric In their rate of growth whereas Stage II mounds had an arithmetic growth rate. Stage III mounds showed a negative growth rate. The distribution patterns of colonies were found to be isolated and random (prairie and woodland habitats), uniform (prairie habitat), and clumped (woodland habitat). The means by which new colonies were established varied with the habitat. Indirect evidence indicates that isolated prairie and wood land colonies are probably founded by solitary queens following the marriage flight, while mounds within clusters were founded by the process of colony division. A relatively rare process, colony translocation, resulted in the abandonment of one nest in favor of another of recent origin. Individual F. oreas comptula nests were, for the most part, asymmetrical in shape with little change in morphology (except size) between Stage I and Stage III nests. No relationship was noted between major/minor ratios and nest size. The sequence of events leading to colony senescence as observed in F. obscuripes was net found to apply to this species. Clusters of F. oreas comptula nests, usually associated with dense stands of Kentucky blue grass, were not found to be composed of discrete colonies but were parts of a complex of interconnected nests. The movement of tagged workers and the transfer of brood between nests indicated that such clusters were polydomous. Isolated and randomly dispersed colonies were rare. The establishment of new colonies was through the process of colony budding. Spatial separation occasionally resulted in the establishment of secondary polydomous clusters

Rapid progression is associated with lymphoid follicle dysfunction in SIV-infected infant rhesus macaques.

HIV-infected infants are at an increased risk of progressing rapidly to AIDS in the first weeks of life. Here, we evaluated immunological and virological parameters in 25 SIV-infected infant rhesus macaques to understand the factors influencing a rapid disease outcome. Infant macaques were infected with SIVmac251 and monitored for 10 to 17 weeks post-infection. SIV-infected infants were divided into either typical (TypP) or rapid (RP) progressor groups based on levels of plasma anti-SIV antibody and viral load, with RP infants having low SIV-specific antibodies and high viral loads. Following SIV infection, 11 out of 25 infant macaques exhibited an RP phenotype. Interestingly, TypP had lower levels of total CD4 T cells, similar reductions in CD4/CD8 ratios and elevated activation of CD8 T cells, as measured by the levels of HLA-DR, compared to RP. Differences between the two groups were identified in other immune cell populations, including a failure to expand activated memory (CD21-CD27+) B cells in peripheral blood in RP infant macaques, as well as reduced levels of germinal center (GC) B cells and T follicular helper (Tfh) cells in spleens (4- and 10-weeks post-SIV). Reduced B cell proliferation in splenic germinal GCs was associated with increased SIV+ cell density and follicular type 1 interferon (IFN)-induced immune activation. Further analyses determined that at 2-weeks post SIV infection TypP infants exhibited elevated levels of the GC-inducing chemokine CXCL13 in plasma, as well as significantly lower levels of viral envelope diversity compared to RP infants. Our findings provide evidence that early viral and immunologic events following SIV infection contributes to impairment of B cells, Tfh cells and germinal center formation, ultimately impeding the development of SIV-specific antibody responses in rapidly progressing infant macaques

Low frequency of broadly neutralizing HIV antibodies during chronic infection even in quaternary epitope targeting antibodies containing large numbers of somatic mutations

Neutralizing antibodies (Abs) are thought to be a critical component of an appropriate HIV vaccine response. It has been proposed that Abs recognizing conformationally dependent quaternary epitopes on the HIV envelope (Env) trimer may be necessary to neutralize diverse HIV strains. A number of recently described broadly neutralizing monoclonal Abs (mAbs) recognize complex and quaternary epitopes. Generally, many such Abs exhibit extensive numbers of somatic mutations and unique structural characteristics. We sought to characterize the native antibody (Ab) response against circulating HIV focusing on such conformational responses, without a prior selection based on neutralization. Using a capture system based on VLPs incorporating cleaved envelope protein, we identified a selection of B cells that produce quaternary epitope targeting Abs (QtAbs). Similar to a number of broadly neutralizing Abs, the Ab genes encoding these QtAbs showed extensive numbers of somatic mutations. However, when expressed as recombinant molecules, these Abs failed to neutralize virus or mediate ADCVI activity. Molecular analysis showed unusually high numbers of mutations in the Ab heavy chain framework 3 region of the variable genes. The analysis suggests that large numbers of somatic mutations occur in Ab genes encoding HIV Abs in chronically infected individuals in a non-directed, stochastic, manner

Cigarette Smoking Interferes With Treatment of Hypertension

• We retrospectively analyzed two studies to determine whether smoking affected the treatment of hypertension. In a study of the effects of propranolol hydrochloride (a hepatically metabolized β-blocker) vs hydrochlorothiazide, 108 smokers and 232 nonsmokers were randomized to the propranolol treatment group. The propranolol-treated smokers tended to be younger, taller, thinner, and were more likely to be black. This group also had an initial blood pressure reduction (± SD) of -7.9 ± 12.9/ -8.7 ± 8.4 mm Hg compared with -10.7 ± 13.0/ -10.9 ± 7.1 mm Hg for the nonsmokers. Blood pressure increased less during the one-year maintenance period for the nonsmokers. However, when analyzed by race, this effect was seen in blacks, but not in whites. Diastolic blood pressure tended to be reduced more in nonsmokers (vs smokers) receiving hydrochlorothiazide (-12.1 ± 6.7 vs -10.7 ± 6.7 mm Hg, respectively). The second study compared the effects of nadolol (a renally excreted β-blocker) with bendroflumethiazide. There were no significant effects on blood pressure for either of these drugs. In both studies, there was a greater tendency for smokers to be terminated from the study irrespective of drug group. We conclude that cigarette smoking does interfere with the treatment of hypertension in general, and especially with reduction of blood pressure by propranolol in black patients.(Arch Intern Med 1988;148:2116-2119

Large-scale genomics unveil polygenic architecture of human cortical surface area

Little is known about how genetic variation contributes to neuroanatomical variability, and whether particular genomic regions comprising genes or evolutionarily conserved elements are enriched for effects that influence brain morphology. Here, we examine brain imaging and single-nucleotide polymorphisms (SNPs) data from ∼2,700 individuals. We show that a substantial proportion of variation in cortical surface area is explained by additive effects of SNPs dispersed throughout the genome, with a larger heritable effect for visual and auditory sensory and insular cortices (h2∼0.45). Genome-wide SNPs collectively account for, on average, about half of twin heritability across cortical regions (N=466 twins). We find enriched genetic effects in or near genes. We also observe that SNPs in evolutionarily more conserved regions contributed significantly to the heritability of cortical surface area, particularly, for medial and temporal cortical regions. SNPs in less conserved regions contributed more to occipital and dorsolateral prefrontal cortices