Division History Research Articles

Differential expansion of human primitive hematopoietic stem cell subsets: Correlation between phenotype, cell division history and frequency scid repopulating cells

CD34+ cells were isolated from G-CSF mobilized normal volunteers and cultured for 4 days in serum-free medium (X-VIVO 15) in the presence of SCF (20 ng/ml) + TPO (50 ng/ml) + FLT-3L (50 ng/ml). The phenotype (CD38, Thy-1, c-kit, HLA-DR) and cell division history (CFSE labeling) of CD34+ cells were examined. The frequency of LTC-IC and SCID repopulating cells (SRC) was measured by limiting dilution assays. After 4 days, the total number of CD34+ cells was maintained but a 25% reduction in the frequency of CFU and a 5-fold increase in LTC-IC were observed. The percentage of CD34+CD38− and CD34+DR− cells increased 57 and 5 fold, respectively, as > 85% of the CD38− and DR− cells divided 5 to 6 times from Day 0 to Day 4. The percentage of CD34+/c-kit+ was maintained after 4 days of culture even though > 90% of the cells had divided 2 to 5 times. In contrast, there was a 6-fold reduction in Thy-1+ cells while 60% of the Thy-1+ cells detected at Day 4 had undergone 0 to 2 divisions. Cultures of sorted CD34+Thy-1+ cells indicated that 3 or more cell divisions resulted in a gradual loss of Thy-1 expression. This data indicates that the combination of SCF+TPO+FLT-3L preferentially expands CD34+CD38− and DR− subsets. Data correlating CD34+ subsets, number of cell divisions and frequency of LTC-IC and SRC will be presented.

Flow cytometric cell division tracking using nuclei

Labeling cells with 5-(and-6) carboxyfluorescein diacetate succinimidyl ester (CFSE) allows their subsequent division history to be determined by flow cytometry. Whether nuclei isolated from CFSE-labeled cells retain any or sufficient dye to reveal the same division history was unknown. If division tracking in nuclei were possible, it would enable the development of new methods for monitoring quantitative changes in nuclei components and how these might vary with successive divisions. Nuclei from CFSE-labeled B cells were prepared by lysing whole cells with nonionic detergent Nonidet P-40 (NP-40). The purified nuclei were subsequently fixed with paraformaldehyde and permeabilized with Tween 20 in order to perform intranuclear staining. Purified nuclei displayed the equivalent asynchronous cell division profile as intact cells. Furthermore, the possibility of simultaneously monitoring division history with intranuclear staining was established by labeling bromodeoxyuridine (BrdU) incorporated into DNA during a brief pulse prior to harvesting cells. This result was verified with the staining of proliferating cell nuclear antigen (PCNA). In addition, aminoactinomycin D (7-AAD) staining established that cell cycle stage and cell division history could be simultaneously determined. Our results demonstrate that cell division history is retained in purified cell nuclei after CFSE labeling and can be used in combination with intranuclear immunofluorescent labeling and DNA staining to provide a comprehensive analysis of nuclei by flow cytometry. This method should prove useful for assessing differential nuclear translocation and accumulation of molecular components during consecutive division rounds and during different stages of the cell cycle.

Divided we stand: tracking cell proliferation with carboxyfluorescein diacetate succinimidyl ester.

Most techniques for assessing cell division can either detect limited numbers of cell divisions (bromodeoxyuridine incorporation) or only quantify overall proliferation (tritiated thymidine incorporation). In the majority of cases, viable cells of known division history cannot subsequently be obtained for functional studies. The cells of the immune system undergo marked proliferation and differentiation during the course of an immune response. The relative lack of an organized structure of the lymphohaemopoietic system, in contrast with other organ systems, makes lineage interrelationships difficult to study. Coupled with the remarkable degree of mobility engendered by recirculation, the differentiation occurring along with cell division in the immune system has not been readily accessible for investigation. The present article reviews the development of a cell division analysis procedure based on the quantitative serial halving of the membrane permeant, stably incorporating fluorescent dye carboxyfluorescein diacetate succinimidyl ester (CFSE or CFDA, SE). The technique can be used both in vitro and in vivo, allowing eight to 10 successive divisions to be resolved by flow cytometry. Furthermore, viable cells from defined generation numbers can be sorted by flow cytometry for functional analysis.

A Mathematical Model on Germinal Center Kinetics and Termination

We devise a mathematical model to study germinal center (GC) kinetics. Earlier models for GC kinetics are extended by explicitly modeling 1) the cell division history of centroblasts, 2) the Ag uptake by centrocytes, and 3) T cell dynamics. Allowing for T cell kinetics and T-B cell interactions, we study the role of GC T cells in GC kinetics, GC termination, and B cell selection. We find that GC T cells play a major role in GC formation, but that the maintenance of established GC reactions requires very few T cells only. The results therefore suggest that the termination of a GC reaction is largely caused by lack of Ag on the follicular dendritic cells and is hardly influenced by Th cells. Ag consumption by centrocytes is the major factor determining the decay rate of the antigenic stimulus during a GC reaction. Investigating the effect of the Ag dose on GC kinetics, we find that both the total size of the GC and its duration are hardly influenced by the initial amount of Ag. In the model this is due to a buffering effect by competition for limited T cell help and/or competition between proliferating centroblasts.

Thrombopoietin, flt3, and kit ligands together suppress apoptosis of human mobilized CD34 + cells and recruit primitive CD34 +Thy-1 + cells into rapid division

Various combinations of cytokines have profoundly different effects on inhibition of apoptosis and stimulation of self-renewal division of hematopoietic stem cells (HSC) in short-term, ex vivo culture. Our goal was to quantitate expansion of cells with a primitive CD34 + Thy-1 + phenotype, as well as cell cycling, division history, differentiation, and apoptosis of CD34 + cells enriched from normal donor mobilized peripheral blood (MPB) cells. The balance of these parameters determines the net number of transplantable HSC produced in ex vivo cultures. Comparing several different combinations of cytokines added to 90-hour cultures of MPB CD34 + cells, thrombopoietin (TPO), flt3 ligand (FL), and c-kit ligand (KL) gave the best result, with the lowest percentage of apoptotic cells and a mean 1.2-fold increase in the number of CD34 + Thy-1 + cells. A combination of interleukin 3 (IL-3), interleukin 6 (IL-6), and leukemia inhibitory factor (LIF) gave the worst outcome, including a decrease of CD34 + Thy-1 + cell number to a mean of 30% of the starting cell number. Cell division history was tracked using the dye 5-(and 6-) carboxyfluorescein diacetate succinimidyl ester (CFSE). Division of CD34 + Thy-1 + cells was faster and more synchronous in TPO, FL, and KL than in IL-3, IL-6, and LIF, which left a significant proportion of CD34 + cells undivided. Such detailed analyses of short-term, ex vivo cultures generated “replication scores,” which allowed prediction of a sixfold improvement of the efficiency of gene transduction of primitive hematopoietic progenitors from MPB, using TPO, FL, and KL to replace IL-3, IL-6, and LIF. Analysis of retroviral transduction efficiency confirmed the increase of transgene expression from MPB primitive hematopoietic progenitors assayed after stromal culture was fivefold, validating the usefulness of multiparameter analysis of short-term cultures for survival and replication of CD34 + Thy-1 + cells.

Teaching Research and Writing to Upper Division History Majors: Contexts, Sources, Rhetorical Strategies

Teaching Research and Writing to Upper Division History Majors: Contexts, Sources, Rhetorical Strategies

Seasoned by Salt A Historical Album of the Outer Banks (review)

bates in the South and North about the future ofblacks newly freed following the Civil War. His book teases us as well to reflect on the struggles for racial equality in our own century. Seasoned by Salt A Historical Album of the Outer Banks By Rodney Barfield University of North Carolina Press, 1996 192 pp. Cloth, $34.95; paper, $18.95 Reviewed by Loyd Little, author of three novels and winner of the Pen-Hemingway award. He is presendy communications officer at the Frank Porter Graham Child Development Center, University of North Carolina at Chapel Hill. Around four in the afternoon on 1 2July 1996, the wind ofBertha reached a maximum of 105 miles per hour at our home on the mainland side ofBogue Sound across from Salter Path. The plywood was up; the boat and car had been moved to high ground; and water jugs were full. The wind was knotted with salt water, destructiveness, darkness, and its roar vibrated in every nail and board. Through the glass portion ofthe front door, I watched the water climb closer, and quickly. Normally, the sound was one hundred feet away and eight feet lower than our home. But at 4:00 p.m., the water was within a few feet of the porch. The waves on the sound were about five-feet high, and each time a wave roiled upward, the wind snatched the top two feet and threw it across the front of our home, like a giant slinging a van-sized bucket ofwater. Several hours earlier, our eighty-foot pier had broken apart and disappeared, and trees already lay uprooted around the house. We had lost our electricity early that morning, and only later did I find out that at the moment I was looking tiirough the door, the eye of Bertha was crossing onto the mainland thirty miles south at Snead's Ferry. Still, compared with the legendary San Ciriaco hurricane that forever changed Shackleford Banks, east ofBeaufort, Bertha was just a bad blow. In Seasonedby Salt, author Rodney Barfield speaks eloquendy and dioughtfully about the forces such as San Ciriaco that shaped the people and the landscape of North Carolina's Outer Banks during the late nineteenth and early twentieth centuries. Barfield, director of the North Carolina Maritime Museum in Beaufort, says the notion of his book grew from listening to museum visitors as they looked at pictures and speculated on life and times a century ago. "There is something inherent in recorded images from the past that touches us at our very centers," he writes. Reviews 87 Women and boys mending nets at Manteo, ca. 1900. Courtesy ofthe North Carolina Collection, University ofNorth Carolina at ChapelHill. Seasoned by Salt, printed in an oversized format of eight-by-nine inches, focuses primarily on the period from the Civil War to the mid-1920s. The book is divided into four sections: "An Overview of the Outer Banks," "The Civil War," "Storms and Shipwrecks," and "Sharpies and Other Boats." The Outer Banks are considered those barrier islands from Currituck Banks at the Virginia—North Carolina border to Core Banks, whose southernmost point is Cape Lookout. However, Barfield includes Shackleford Banks, which darts westward from Cape Lookout, because Shackleford's story is as dramatic as that of any of the other islands. Barfield gathered his information from books, early records, and talks witii museum visitors and witii the oldest generation on the banks. Seasoned by Salt is not a history of the Outer Banks and it is not a definitive work. Its goal, Barfield writes, is to focus on the "collective memories and lore of the residents of die large forces that shaped their personalities and heritage." In this Barfield succeeds admirably. His prose is clear, clean, and careful, and his research is detailed. But more than the writing, the magnificent pictures and drawings—more than 1 50—will entice readers to return again and again to Seasoned by Salt. The photographs , many published for the first time, come from the archives ofthe Maritime Museum, the Cape Lookout National Seashore, the North Carolina State Division ofArchives and History, and the North Carolina Collection at the University of North Carolina at...

ANATOMY OF A FATAL BUSINESS STRATEGY

ABSTRACTThe reported interpretive case study is focused on the genesis and the maturation of a catastrophic division‐level business strategy and affords an uncommon glimpse of the intraorganizational dynamics of failure. A descriptive account of the focal division's history and the emergence of the fatal strategy provides the backdrop for subsequent diagnoses. Comparative analysis is used to identify salient differences between the focal strategy and the strategies of three sectoral pacesetters; then, the processes that spawned the noted differences are examined within the context of organizational and behavioural decision theory.

Determination of lymphocyte division by flow cytometry

Techniques currently available for determining cell division are able to show one or, at best, a limited number of cell divisions. Other methods exist which can quantify overall division, but tell nothing about the division history of individual cells. Here we present a new technique is which an intracellular fluorescent label is divided equally between daughter cells upon cell division. The technique is applicable to in vitro cell division, as well as in vivo division of adoptively transferred cells, and can resolve multiple successive generations using flow cytometry. The label is fluorescein derived, allowing monoclonal antibodies conjugated to phycoerythrin or other compatible fluorochromes to be used to immunophenotype the dividing cells.

The Rehabilitation Teachers Division of Migdal Or

This article describes the Rehabilitation Teachers Division—one of the four units of an Israeli rehabilitation agency, Migdal Or. It discusses the division's history, structure, and unique features and shows that although many ideas and models were taken from programs in other countries, they have been adapted to the needs, assets, and cultures of blind and visually impaired people in Israel.

Mathematical model for the cell-differentiation based on spatial arrangements and division history

Mathematical model for the cell-differentiation based on spatial arrangements and division history

The position and growth of lateral roots on cultured root axes of tomato,Lycopersicon esculentum (Solanaceae)

Root axes of tomato (Lycopersicon esculentum) were cultured in vitro in three different concentrations of sucrose in order to vary their growth rate. Lateral root growth and the initiation of lateral root primordia were studied on each group of axes. Various aspects of primordium initiation, positioning, and emergence were quantified with a view to discovering variable and constant features of these processes. Variable parameters were the rate and frequency of root primordium emergence. Constant parameters, at least under the prevailing conditions, were the spacing between successive laterals and primordia, and the position of the primordia in relation to the vascular system. A model of primordium initiation is presented which combines controls determined by the divisional history of the potential primordium cell and by the vascular pattern.

Using Computers in Lower Division History Courses

Article published in Teaching History by van Hartesveldt.

The Variation of Hematopoietic Stem Cell Self-Renewal Capacity as a Function of Age: Further Evidence for Heterogenicity of the Stem Cell Compartment

There is substantial evidence for limited proliferative capacity of the hematopoietic progenitors. Hematopoiesis in mice is maintained by primitive stem cells that are assayed by their ability to form spleen colonies (CFU-S). To measure the average proliferative capacity of these cells (CFU-S), bone marrow containing 50-150 CFU-S is injected into lethally irradiated mice, and 14 days later, the number present in the recipient marrow is measured. In fetal life between 13 and 16 days of gestation, the hematopoietic stem cells are primarily localized in the liver. There is a decrease in the average proliferative capacity of these stem cells as they progress from fetal life into adulthood. This proliferative capacity of these significantly increases in late adulthood. However, if one scores maximum self-renewal or proliferative capacity by another assay consisting of the serial transplantation of marrow at 14-day intervals, this capacity is unchanged with age. These observations can be explained by considering the stem cell compartment as a continuum of cells whose self-renewal capacity varies inversely with their divisional history. All stem cells participate in repopulation when the pool needs rapid expansion (fetal life). During steady-state repopulation (adult life), clones are selected on the basis of their divisional history, those with the greatest proliferative history being selected. Thus, the average proliferative capacity of the remaining stem cells will increase as the adult animal ages, since stem cells of low proliferative potential have been consumed. The maximal self-renewal capacity will remain unchanged, since this measures the spared earliest cells with the highest proliferative capacity.

Review of the Thirty-Sixth Annual Meeting, Atlanta, Georgia

Southeastern Geographer Vol. 22, No. 1, May 1982, pp. 87-88 REVIEW OF THE THIRTY-SIXTH ANNUAL MEETING, ATLANTA, GEORGIA James S. Fisher The Thirty-Sixth Annual Meeting of the Southeastern Division ofthe Association of American Geographers was held November 22-24, 1981, at the Marriott Hotel at Perimeter Center, Atlanta, Georgia. The Department of Geography, Georgia State University, served as the host institution. The Local Arrangements Committee, chaired by Richard Pillsbury, included all members of the Department of Geography at Georgia State University. The final registration count of 401 persons makes the Atlanta meeting attendance one of the highest in divisional history. The meeting unofficially began Saturday evening with a wine and cheese reception for early arrivals at the home of Richard and Pat Pillsbury , Tucker, Georgia. Sunday activities included four field trips and a day-long Map Library Workshop arranged by Helenjane Armstrong, University of Florida. The Sunday evening opening session was presided over by President Stephen S. Rirdsall. The keynote address, "University Involvement in International Natural Resource Development," was given by Dr. S. Eugene Younts, Vice President for Services, University of Georgia. A plenary session followed as the first of 26 sessions. Three sessions consisted wholly of student papers submitted for M.A. and Ph.D. Honors competition. The program included three sessions on physical geography, two on historical geography, and others on transportation , population and migration, social-medical, economic, agriculture , and cultural geography. There were special sessions on travel patterns and impacts (arranged by Robert G. Cromley and Ronald L. Mitchelson) and on political geography (arranged by Christine Drake), and a discussion session on "The Working Woman" sponsored by the Committee on the Status of Women in Geography in the Southeast. The regional open business meeting of the A.A.G. Committee on the Status Dr. Fisher is Associate Professor of Geography at the University ofGeorgia in Athens, GA 30602. He served as Vice-President and as Program Chairman of the Division during, 1981. 88Southeastern Geographer of Women in Geography was presided over by Jackalie Blue. Two forums on "Careers in Geography" were arranged by Susan Moorlag. At the Business Meeting it was announced that Neal Lineback, University of Alabama and Charles Kovacik, University of South Carolina, were elected President and Treasurer, respectively, for 1982-1983. Elected to the Nominating Committee for 1981 were Charles M. Good, Ted Mealor, and Dennis Lord, Chairperson. The newly elected Honors Committee includes Julian Minghi, David Niddrie, and Sallie Ives, Chairperson. Sidney R. Jumper was awarded Honorary Life Membership . It was noted that James R. Anderson, an Honorary Life Member of the Division, passed away on December 24, 1980. Morton D. Winsberg presented memorial commentary. At the Honors Luncheon Robert W. Morrill, on behalf of the Honors Committee, announced that Ellen K. Cromley, University of Kentucky, won the award for best Ph.D. student paper and that Jonathan Phillips, East Carolina University, won the award for best M.A. student paper. Richard L. Morrill, President of the Association of American Geographers , presented the luncheon address, "The Status of Geography in the Eighties." ...

How the Music Division of the New York Public Library Grew-A Memoir. Part IV: Exhibitions 1966-1980

Parts I-III of Philip Miller's and my account of the Music Division's history have reported the ideas, the activities, and the achievements of many members of our staffs and their associates, both in the library and in numerous outside constituencies. In writing of our exhibitions, I am reporting on and delineating the ideas of more recent colleagues.1 Most of the activities in a research library are the result of joint effort, and exhibitions fit into such a pattern. In the descriptions of exhibitions that follow I have listed the staff members responsible; also, in a number of cases, I am literally quoting their words, especially in descriptions which include excerpts from press releases issued by the library in announcing an exhibition. Whether or not exhibitions are a worthwhile endeavor for the belea-

"Journal of a Secesh Lady": The Diary of Catherine Ann Devereux Edmondston, 1860-1866 (review)

354CIVIL WAR HISTORY Brugger is certainly critical of Tucker. He sees him as self important, shallow, and devoid of self-criticism. In the end he calls Tucker "an intellectual failure and really not an intellectual at all" because, among other things, he could not distinguish between the study of ideas and their advocacy (p. 204). It would have been better if Brugger had written a book that explored those deficiencies, for in the tension between the ideas of the present and the past lie some of the most valuable historical insights. But perhaps the real truth is that the subject was not quite worthy of the author. Carl N. Decler Stanford University "Journal of a Secesh Lady": The Diary of Catherine Ann Devereux Edmondston, 1860-1866. Edited by Beth Gilbert Crabtree andJames W. Patton. (Raleigh: North Carolina Division ofArchives and History, 1979. Pp. xxxvüi, 797. $29.00.) In many ways "Journal of a Secesh Lady" qualifies as the North Carolina counterpart to Mary Boykin Chesnut's famous Diary from Dixie. Like Mrs. Chesnut, Catherine Devereux Edmondston was the literate and articulate wife of a well-to-do planter. Moreover, Kate Edmondston was childless and socially connected to many Confederate leaders, counting among her relations Congressmen Josiah Turner and Henry W. Miller, Lieutenant General Leónidas Polk, and others of influence at the state level. Although she did not have access to die highest level of Confederate leadership, her diary is as voluminous as Mrs. Chesnut's and touches upon nearly as wide a range of topics. The authors of these diaries, however, were dissimilar women. Mary Boykin Chesnut's intelligence and independence of thought shine through in numerous entries in her diary, which is remarkable for its critical, probing comments about the status quo. Moreover, Mrs. Chesnut was an introspective person who had achieved considerable distance between herself and her associates. By contrast, Kate Edmondston was conventional and traditional, took pride in the fact, and seemed never to doubt that what existed was right. About herself she was generally unperceptive and frequently self-righteous. Rather than raising questions about her society, she endorsed it and trumpeted her devotion as a "secesh lady." Consequently, the Edmondston "Journal" is different, but not necessarily less valuable. Though it contains little critical examination of the events it chronicles, it does provide evidence of a frank and adamant planter mentality. The diary does not examine Confederate society, but it faithfully reflects a part of that society, and for this reason it offers many rewards to the reader who brings critical intelligence to bear on its pages. BOOK REVIEWS355 Kate Edmondston was not a typical North Carolinian. Her peculiarities brought much strain to family relationships during the secession crisis, as she alone among her relatives repudiated the beloved Union and voiced strong feelings about Southern rights and Southern patriotism. In exasperation Kate's sister finally told her, "You slave holders have lived so long on your plantations with no one to gain say or contradict you & the negroes only to look up and worship you, that you expect to govern every body & have it all your own way." Indeed, Kate's sister had identified the crux of the matter. The Edmondston diary is a species of planter's diary, and it reveals the planter's mentality. Kate Edmondston's world was her plantation. She and her husband lived a rather simple, isolated, but patterned life there that satisfied them both. She wanted nothing to disturb diat life, with its luxuries and security, her gardening and reading. Her diary contains the complaints common among planters about taxes and the tax-in-kind, impressment, suspension of habeas corpus, and Davis' plan for emancipation. While expecting military valor of other males, she felt unembarrassed relief that her husband, after losing a colonel's commission, never served in the Confederate army. In the pinch Mrs. Edmondston defined national interest by her own personal interest, as did too many Southern planters. Yet the "Journal!' demonstrates that Jefferson Davis' enunciation of Confederate ideology contained great appeal for Kate Edmondston. The peaceful, inactive demeanor of this woman concealed belligerent hostility and condemnation of the Yankees. Echoing Davis' words, she excoriated what she saw as...

Organization of haemopoietic stem cells: the generation-age hypothesis.

This paper proposes that the previous division history of each stem cell is one determinant of the functional organization of the haemopoietic stem cell population. Stem cells from a lineage of stem cells which have generated many stem cells (older stem cells) are used in the animal to form blood before stem cells which have generated few stem cells (younger stem cells). The stem cell generating capacity of a lineage of stem cells is finite. After a given number of generations a stem cell is lost to the stem cell compartment by forming two committed precursors of the cell lines. Its part in blood formation is taken by the next oldest stem cell. We have called this proposal the generation-age hypothesis. Experimental evidence in support of the proposal is presented. We stripped away older stem cells from normal bone marrow and 13 day foetal liver with phase-specific drugs and revealed a younger population of stem cells whose capacity for stem cell generation was three- to four-fold greater than that of the average normal, untreated population. We aged normal stem cells by continuous irradiation and serial retransplantation and found that their stem cell generative capacity had declined eight-fold. We measured the stem cell generative capacity of stem cells in the bloodstream. It was a half to a quarter that of normal bone marrow stem cells and we found a subpopulation of circulating stem cells whose capacity for stem cell generation was an eighth to a fortieth that of normal femoral stem cells. This subpopulation was identified by its failure to express the brain-associated antigen which was present on 75% of normal femoral stem cells but was not found on their progeny, the committed precursors of granulocytes.

Use of yttrium 90 in persistent synovitis of the knee. I. Retention in the knee and spread in the body after injection.

<h3>Abstract</h3> Recently, the combined scRNA-seq and CRISPR/Cas9 genome editing technologies have enabled simultaneous readouts of gene expressions and lineage barcodes, which allows for the reconstruction of the cell division tree, and makes it possible to trace the origin of each cell type. Computational methods are emerging to take advantage of the jointly profiled scRNA-seq and lineage barcode data to better reconstruct the cell division history or to infer the cell state trajectories. Here, we present TedSim (single cell <b>Te</b>mporal <b>d</b>ynamics <b>Sim</b>ulator), a simulator that simulates the cell division events from the root cell to present-day cells, simultaneously generating the lineage barcodes and scRNA-seq data. In particular, TedSim generates cells from multiple cell types through cell division events. TedSim can be used to benchmark and investigate computational methods which use either or both of the two types of data, scRNA-seq and lineage barcodes, to study cell lineages, ancestral cells or cell trajectories. TedSim is available at: https://github.com/Galaxeee/TedSim.

A Collection of Airborne Cadence Chants

THE TEXTS included here were collected at Fort Campbell, Kentucky, the home of the IoIst Airborne Division, in April of 1961. The idea for such a project reverted back to my own tour of duty as a parachutist from 1954 to I956; aware that sung cadences prevailed among soldiers, I thought it worthwhile to get some of these cadence chants on tape-something which to my knowledge has not been attempted before. Therefore, with help from the personnel of the Public Information Office at the base, who lent me a small transistor tape recorder, I was able to run beside the troops during their daily exercise and gather the material presented here. By way of introduction it seems necessary to sketch in something about the Ioist Airborne Division in general and the paratrooper in particular. The division's history, though short in span of years, reveals a number of achievements. Activated in 1942 as one of the first groups in American Armed Forces' history, the Ioist jumped both at Normandy and in Holland during the war prior to receiving a unit citation at Mourmelon, France, in I945. Shortly after the Axis capitulated, the United States government deactivated the unit from status, but reformed it again in 1956, when the Ioist became one of the first divisions to be shaped into battle groups rather than battalions and regiments.1 Ironically, little of the unit's outstanding background is reflected in the lore of the individual paratrooper. Many of the men who now make up the ranks of the Ioist scarcely remember the Second World War. (the average age of the enlisted private is eighteen.) Their interests converge rather on the narrowness of their regimented existence-their rationed food, their training, their curtailed freedom, and their next jump. Yet the parachutist remains a rarity amid the overall conformity of Army life, for he has volunteered to jump out of a plane, and his training stresses physical fitness, fortitude, and mental alertness; consequently, the soldier represents the army's finest fighting men. It is hardly surprising that the paratrooper himself believes he is the roughest, toughest bundle of airborne hell ever to pass through the doors of an aircraft. Airborne soldiers, like Marines, are noted for their devil-may-care attitude and their inbred esprit de corps. They possess one thing which elevates them above the miserable straight leg (non-jumping soldier): the touch of insanity it takes to step out of an airplane at fifteen hundred feet. To accomplish this feat, however, the novice must suffer through three or four weeks of intensive training, climaxed in the final week by five consecutive jumps. At the end of this jump school the trooper receives his wings, the emblem of his prowess, and these, along with his jump boots, he treasures above all other belongings. His training complete, the new parachutist returns to his own outfit to begin the endless round of army life. When off maneuvers, the soldier's day usually follows a set pattern: up at five-thirty for muster; chow at six followed by calisthenics and a two to three mile