Both asymmetric mitotic segregation and cell-to-cell invasion are required for stable germline transmission of Wolbachia in filarial nematodes.

Parasitic filarial nematodes that belong to the Onchocercidae family live in mutualism with Wolbachia endosymbionts. We developed whole-mount techniques to follow the segregation patterns of Wolbachia through the somatic and germline lineages of four filarial species. These studies reveal multiple evolutionarily conserved mechanisms that are required for Wolbachia localization to the germline. During the initial embryonic divisions, Wolbachia segregate asymmetrically such that they concentrate in the posteriorly localized P(2) blastomere, a precursor to the adult germline and hypodermal lineages. Surprisingly, in the next division they are excluded from the germline precursor lineage. Rather, they preferentially segregate to the C blastomere, a source of posterior hypodermal cells. Localization to the germline is accomplished by a distinct mechanism in which Wolbachia invade first the somatic gonadal cells close to the ovarian distal tip cell, the nematode stem cell niche, from the hypodermis. This tropism is associated with a cortical F-actin disruption, suggesting an active engulfment. Significantly, germline invasion occurs only in females, explaining the lack of Wolbachia in the male germline. Once in the syncytial environment of the ovaries, Wolbachia rely on the rachis to multiply and disperse into the germ cells. The utilization of cell-to-cell invasion for germline colonization may indicate an ancestral mode of horizontal transfer that preceded the acquisition of the mutualism

An Investigation of the Kinematic and Microphysical Control of Lightning Rate, Extent and NOx Production using DC3 Observations and the NASA Lightning Nitrogen Oxides Model (LNOM)

The Deep Convective Clouds and Chemistry (DC3) experiment seeks to quantify the relationship between storm physics, lightning characteristics and the production of nitrogen oxides via lightning (LNOx). The focus of this study is to investigate the kinematic and microphysical control of lightning properties, particularly those that may govern LNOx production, such as flash rate, type and extent across Alabama during DC3. Prior studies have demonstrated that lightning flash rate and type is correlated to kinematic and microphysical properties in the mixedphase region of thunderstorms such as updraft volume and graupel mass. More study is required to generalize these relationships in a wide variety of storm modes and meteorological conditions. Less is known about the coevolving relationship between storm physics, morphology and threedimensional flash extent, despite its importance for LNOx production. To address this conceptual gap, the NASA Lightning Nitrogen Oxides Model (LNOM) is applied to North Alabama Lightning Mapping Array (NALMA) and Vaisala National Lightning Detection Network(TM) (NLDN) observations following ordinary convective cells through their lifecycle. LNOM provides estimates of flash rate, flash type, channel length distributions, lightning segment altitude distributions (SADs) and lightning NOx production profiles. For this study, LNOM is applied in a Lagrangian sense to multicell thunderstorms over Northern Alabama on two days during DC3 (21 May and 11 June 2012) in which aircraft observations of NOx are available for comparison. The LNOM lightning characteristics and LNOX production estimates are compared to the evolution of updraft and precipitation properties inferred from dualDoppler and polarimetric radar analyses applied to observations from a nearby radar network, including the UAH Advanced Radar for Meteorological and Operational Research (ARMOR). Given complex multicell evolution, particular attention is paid to storm morphology, cell mergers and possible dynamical, microphysical and electrical interaction of individual cells when testing various hypotheses

Software for Partly Automated Recognition of Targets

The Feature Analyst is a computer program for assisted (partially automated) recognition of targets in images. This program was developed to accelerate the processing of high-resolution satellite image data for incorporation into geographic information systems (GIS). This program creates an advanced user interface that embeds proprietary machine-learning algorithms in commercial image-processing and GIS software. A human analyst provides samples of target features from multiple sets of data, then the software develops a data-fusion model that automatically extracts the remaining features from selected sets of data. The program thus leverages the natural ability of humans to recognize objects in complex scenes, without requiring the user to explain the human visual recognition process by means of lengthy software. Two major subprograms are the reactive agent and the thinking agent. The reactive agent strives to quickly learn the user s tendencies while the user is selecting targets and to increase the user s productivity by immediately suggesting the next set of pixels that the user may wish to select. The thinking agent utilizes all available resources, taking as much time as needed, to produce the most accurate autonomous feature-extraction model possible

The Kinematic and Microphysical Control of Lightning Rate, Extent and NOX Production

The Deep Convective Clouds and Chemistry (DC3) experiment seeks to quantify the relationship between storm physics, lightning characteristics and the production of nitrogen oxides via lightning (LNOx). The focus of this study is to investigate the kinematic and microphysical control of lightning properties, particularly those that may govern LNOx production, such as flash rate, type and extent across Alabama during DC3. Prior studies have demonstrated that lightning flash rate and type is correlated to kinematic and microphysical properties in the mixed-phase region of thunderstorms such as updraft volume and graupel mass. More study is required to generalize these relationships in a wide variety of storm modes and meteorological conditions. Less is known about the co-evolving relationship between storm physics, morphology and three-dimensional flash extent, despite its importance for LNOx production. To address this conceptual gap, the NASA Lightning Nitrogen Oxides Model (LNOM) is applied to North Alabama Lightning Mapping Array (NALMA) and Vaisala National Lightning Detection Network(TM) (NLDN) observations following ordinary convective cells through their lifecycle. LNOM provides estimates of flash rate, flash type, channel length distributions, lightning segment altitude distributions (SADs) and lightning NOx production profiles. For this study, LNOM is applied in a Lagrangian sense to multicell thunderstorms over Northern Alabama on two days during DC3 (21 May and 11 June 2012) in which aircraft observations of NOx are available for comparison. The LNOM lightning characteristics and LNOX production estimates are compared to the evolution of updraft and precipitation properties inferred from dual-Doppler and polarimetric radar analyses applied to observations from a nearby radar network, including the UAH Advanced Radar for Meteorological and Operational Research (ARMOR). Given complex multicell evolution, particular attention is paid to storm morphology, cell mergers and possible dynamical, microphysical and electrical interaction of individual cells when testing various hypotheses

Invitation of Echoes: Part One

Four strangers are stranded in an old farmhouse by a winter storm. Gilley lives on the farm. Shadows move of their own volition on the farm, and Gilley talks to echoes and sees the dead reflected in mirrors. Gilley\u27s husband, Frank, disappeared over forty years ago. Jason is a college student who seeks Gilley out for an interview. He agrees to help Gilley find Frank. Jesse is a young boy who finds his way to the house after an accident. August is a private investigator whom Jason calls for help in finding Frank. August does not have a shadow nor a reflection of his own, and he can\u27t remember how he lost them. Each wants something that only the others can provide, but each wants to keep their own secrets

Invitation of Echoes: Part One

Four strangers are stranded in an old farmhouse by a winter storm. Gilley lives on the farm. Shadows move of their own volition on the farm, and Gilley talks to echoes and sees the dead reflected in mirrors. Gilley\u27s husband, Frank, disappeared over forty years ago. Jason is a college student who seeks Gilley out for an interview. He agrees to help Gilley find Frank. Jesse is a young boy who finds his way to the house after an accident. August is a private investigator whom Jason calls for help in finding Frank. August does not have a shadow nor a reflection of his own, and he can\u27t remember how he lost them. Each wants something that only the others can provide, but each wants to keep their own secrets

CCR2⁺CD103⁻ intestinal dendritic cells develop from DC-committed precursors and induce interleukin-17 production by T cells

The identification of intestinal macrophages (m phi s) and dendritic cells (DCs) is a matter of intense debate. Although CD103(+) mononuclear phagocytes (MPs) appear to be genuine DCs, the nature and origins of CD103(-) MPs remain controversial. We show here that intestinal CD103(-)CD11b(+) MPs can be separated clearly into DCs and m phi s based on phenotype, gene profile, and kinetics. CD64(-)CD103(-)CD11b(+) MPs are classical DCs, being derived from Flt3 ligand-dependent, DC-committed precursors, not Ly6C hi monocytes. Surprisingly, a significant proportion of these CD103(-)CD11b(+) DCs express CCR2 and there is a selective decrease in CD103(-)CD11b(+) DCs in mice lacking this chemokine receptor. CCR2(+)CD103(-) DCs are present in both the murine and human intestine, drive interleukin (IL)-17a production by Tcells in vitro, and show constitutive expression of IL-12/IL-23p40. These data highlight the heterogeneity of intestinal DCs and reveal a bona fide population of CCR2(+) DCs that is involved in priming mucosal T helper type 17 (Th17) responses

Studies on the comparative physiology of the heart

From the time of Harvey until the middle of the nineteenth century practically nothing that was fundamental had been added to our knowledge of the physiology of the heart - a circumstance which is the more remarkable considering the stimulus to investigation in this very field which the publication of Harvey's immortal work should have afforded. The mid-nineteenth century, however, saw the commencement of investigations along several distinct lines, the results of which were to lead to a greater advance in our knowledge of the heart in the succeeding sixty years than previous hundreds had witnessed. This new era, which we may take as having been initiated by the work of Remak, Stannius and the brothers Weber, has continued to the present day, and as it concerns aspects of cardiac physiology with which it is the business of this paper to deal the question of the cause of the heart beat and of the cause of the effects produced by the extrinsic regulatory nerves.The rapid and indeed sensational advance of endocrinology and the consequent demonstration of the comparatively simple chemical basis of some of the most complicated of physiological processes led to the evolution of a new views point and a new technique in physiological research - hormonic, indeed, in more senses than one. Investigations in this new field by this new technique left practically no organ in the body untouched and so the heart, in common with the other organs, came in for its due share of attention.Soon after the appearance of Loewi's work, which will be reviewed in a later section of this paper, articles appeared almost simultaneously from three different laboratories describing experiments which were interpreted as showing that the rhythmicity of cardiac tissue was due to the action on the otherwise non- rhythmic myocardium of substances r,roduced by, or at least acting through, the special (nodal) system of the heart.Thus Demoor, Professor of Physiology in the University of Brussels, showed that non-rhythmic portions of mammalian cardiac muscle could be made to beat rhythmically if bathed in Locke solution to which had been added an extract of the sinoauricular node, and he concluded from this that the automatic rhythmicity of the heart was dependent on the continuous action on the myocardium of what he called the "substances actives", produced by the sinoauricular node, and, as demonstrated later, found also in the node of Tawara, bundle of His, and the Purkinje tissue of the subendocardium.Haberlandt, of Innsbruck, working independently of Demoor and in ignorance of the latter's work, showed that the sinus venosus of the frog's heart produced a substance - " Herzhormon" - which would initiate rhythmic contractions in the long perfused and quiescent frog ventricle, and to which therefore the normal automaticity of the heart was presumed to be due.Finally, Zwaardemaker, of Utrecht, working mainly with the eel's heart, came to the conclusion as a result of experiments commenced as far back as 1916, that the automaticity of cardiac tissue was due to .the presence in the heart of substances which he called "Automatins" which were produced in various parts of the body by the action of the ß rays of potassium on an inactive precursor which he called "automatinogen ". These automatins were supposed to be concentrated in the special system of the heart, and to work, as it were, from this system as a base.Thus was initiated what has now generally come to be known as the work on the "heart hormones" - an inaccurate though convenient term by which to designate the various substances described by the different workers.It is the purpose of this paper to review the work of each of the three schools, to add the author's own observations, to discuss the whole critically, and, if possible, assess the value and significance of this work

Contributions to the study of histamine antagonists in man: (with additional papers)

The main part of this thesis consists, firstly, of a series of papers illustrating the development of the writer's quantitative approach to the study of the action of histamine antagonists in man; and, secondly, of a note concerning trials of antihistaminics, followed by the description of a pilot trial of one of these drugs. Some repetition has been unavoidable in the published accounts.The supporting part of the thesis consists of two papers, in order of their publication. The first describes some early work on the mode of action of autonomic nerves, and is followed by a short addendum. The second, and more important contribution, deals with the inactivation of adrenaline - thought, at that time, to be the transmitter of adrenergic nerve effects. It is followed by a short addendum extending some of the observations to various mammals, including man. The war interrupted this work, but it was resumed, and extended to include noradrenaline, when that substance became available. A second addendum summarises some of the more recent observations.This work, on histamine antagonists and on adrenaline and noradrenaline, is being continued. Some of the methods developed in it are being success- fully applied to related fields, both by the writer and by some of his pupils