Browsing by Subject "History, 20th Century"

Now showing 1 - 19 of 19

Open Access
A brief history of research synthesis.
(Eval Health Prof, 2002-03) Chalmers, Iain; Hedges, Larry V; Cooper, Harris
Science is supposed to be cumulative, but scientists only rarely cumulate evidence scientifically. This means that users of research evidence have to cope with a plethora of reports of individual studies with no systematic attempt made to present new results in the context of similar studies. Although the need to synthesize research evidence has been recognized for well over two centuries, explicit methods for this form of research were not developed until the 20th century. The development of methods to reduce statistical imprecision using quantitative synthesis (meta-analysis) preceded the development of methods to reduce biases, the latter only beginning to receive proper attention during the last quarter of the 20th century. In this article, the authors identify some of the trends and highlights in this history, to which researchers in the physical, natural, and social sciences have all contributed, and speculate briefly about the "future history" of research synthesis.
Open Access
A tale of two callings.
(J Clin Invest, 2011-10) Lefkowitz, Robert J
Open Access
Allan McLane Hamilton.
(The American journal of psychiatry, 2018-07) Davidson, Jonathan
Open Access
Assault rifles; definitions, evolutionary history and medical consequences.
(Journal of the Mississippi State Medical Association, 1990-12) Severance, HW
In summary, the evolutionary history of assault rifles may be of interest to some medical practitioners. It is important to realize that the term "assault rifle" is incorrectly and overused in the lay press. As a rough generalization, the wounds from such weapons may fall in between those of handguns on one side and full-sized rifles on the other. The major caveat is that there can be major variations in the severity of any wound by any weapon and though it may be of some help in analyzing potential damage, knowledge of the inflicting weapon does not replace the need for good, well established principles of wound management.
Open Access
Bayard Holmes (1852-1924) and Henry Cotton (1869-1933): Surgeon-psychiatrists and their tragic quest to cure schizophrenia.
(Journal of medical biography, 2016-11) Davidson, Jonathan
Early 20th-century medicine was dominated by the infectious theory of disease. Some leading physicians believed that infection or the accumulation of toxic substances from bacterial stasis caused a wide range of diseases, including schizophrenia. In the case of schizophrenia, one theory held that intestinal stasis lead to the bacterial production of toxins that affected brain function, resulting in psychotic illness. This theory predicted that clearing the stasis by drainage or by removal of the offending organ would be curative. Bayard Holmes and Henry Cotton, surgeon-psychiatrists, achieved notoriety for their efforts to cure schizophrenia surgically. Their endeavours were not only a failure but resulted in tragedy to their families and to a wider population. Treatment of their own sons also represented a violation of the ethics of their time. This account describes the life and career of Holmes and Cotton and reappraises their work in the light of recent developments.
Open Access
Carrots and sticks: fertility effects of China's population policies.
(Pap Proc Annu Meet Am Econ Assoc) McElroy, M; Yang, DT
For 20 years following 1949, average total fertility per woman in China hovered just above six children. The year 1970 marked the beginning of persistent fertility declines. By 1980, the rate had dropped to 2.75, and since 1992 it has remained under 2. While some of this transition can be accounted for by broad socioeconomic developments, the extent to which it is attributable to China's unique population policies remains controversial. This paper analyzes household data from the 1992 Household Economy and Fertility Survey (HEFS) to provide the first direct microeconomic empirical evidence on the efficacy of these policies.
Open Access
Enhancing the Hodgkin-Huxley Equations: Simulations Based on the First Publication in the Biophysical Journal.
(Biophys J, 2015-10-06) Moore, John W
The experiments in the Cole and Moore article in the first issue of the Biophysical Journal provided the first independent experimental confirmation of the Hodgkin-Huxley (HH) equations. A log-log plot of the K current versus time showed that raising the HH variable n to the sixth power provided the best fit to the data. Subsequent simulations using n(6) and setting the resting potential at the in vivo value simplifies the HH equations by eliminating the leakage term. Our article also reported that the K current in response to a depolarizing step to ENa was delayed if the step was preceded by a hyperpolarization. While the interpretation of this phenomenon in the article was flawed, subsequent simulations show that the effect completely arises from the original HH equations.
Open Access
Faculty development/mentoring evolution of mentorship in academic medicine.
(Journal of investigative medicine : the official publication of the American Federation for Clinical Research, 2020-03) Das, Samrat
Open Access
Global nitrogen budgets in cereals: A 50-year assessment for maize, rice, and wheat production systems.
(Scientific reports, 2016-01-18) Ladha, JK; Tirol-Padre, A; Reddy, CK; Cassman, KG; Verma, Sudhir; Powlson, DS; van Kessel, C; de B Richter, Daniel; Chakraborty, Debashis; Pathak, Himanshu
Industrially produced N-fertilizer is essential to the production of cereals that supports current and projected human populations. We constructed a top-down global N budget for maize, rice, and wheat for a 50-year period (1961 to 2010). Cereals harvested a total of 1551 Tg of N, of which 48% was supplied through fertilizer-N and 4% came from net soil depletion. An estimated 48% (737 Tg) of crop N, equal to 29, 38, and 25 kg ha(-1) yr(-1) for maize, rice, and wheat, respectively, is contributed by sources other than fertilizer- or soil-N. Non-symbiotic N2 fixation appears to be the major source of this N, which is 370 Tg or 24% of total N in the crop, corresponding to 13, 22, and 13 kg ha(-1) yr(-1) for maize, rice, and wheat, respectively. Manure (217 Tg or 14%) and atmospheric deposition (96 Tg or 6%) are the other sources of N. Crop residues and seed contribute marginally. Our scaling-down approach to estimate the contribution of non-symbiotic N2 fixation is robust because it focuses on global quantities of N in sources and sinks that are easier to estimate, in contrast to estimating N losses per se, because losses are highly soil-, climate-, and crop-specific.
Open Access
'One physical system': Tansley's ecosystem as Earth's critical zone.
(The New phytologist, 2015-05) Richter, Daniel deB; Billings, Sharon A
Integrative concepts of the biosphere, ecosystem, biogeocenosis and, recently, Earth's critical zone embrace scientific disciplines that link matter, energy and organisms in a systems-level understanding of our remarkable planet. Here, we assert the congruence of Tansley's (1935) venerable ecosystem concept of 'one physical system' with Earth science's critical zone. Ecosystems and critical zones are congruent across spatial-temporal scales from vegetation-clad weathering profiles and hillslopes, small catchments, landscapes, river basins, continents, to Earth's whole terrestrial surface. What may be less obvious is congruence in the vertical dimension. We use ecosystem metabolism to argue that full accounting of photosynthetically fixed carbon includes respiratory CO₂ and carbonic acid that propagate to the base of the critical zone itself. Although a small fraction of respiration, the downward diffusion of CO₂ helps determine rates of soil formation and, ultimately, ecosystem evolution and resilience. Because life in the upper portions of terrestrial ecosystems significantly affects biogeochemistry throughout weathering profiles, the lower boundaries of most terrestrial ecosystems have been demarcated at depths too shallow to permit a complete understanding of ecosystem structure and function. Opportunities abound to explore connections between upper and lower components of critical-zone ecosystems, between soils and streams in watersheds, and between plant-derived CO₂ and deep microbial communities and mineral weathering.
Open Access
Ralph Albert Blakelock (1847-1919): Psychiatric hospitalization and the abduction of an American landscape artist.
(Journal of medical biography, 2017-02) Davidson, Jonathan Rt
Ralph Blakelock was a leading American landscape painter. Much of his life was lived in obscurity and destitution. He developed late onset paranoid schizophrenia, resulting in prolonged hospitalization. During his time in hospital, demand for Blakelock's works grew, but he was unable to enjoy any of this success. Instead, the artist fell prey to unscrupulous and unlikely exploitation by a self-appointed guardian, aided and abetted by Blakelock's psychiatrists, which broke his spirit and may well have hastened his demise.
Open Access
Reduction in Mortality after Umbilical Cord Blood Transplantation in Children Over a 20-Year Period (1995-2014).
(Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation, 2019-04) Spees, Lisa P; Martin, Paul L; Kurtzberg, Joanne; Stokhuyzen, Andre; McGill, Lauren; Prasad, Vinod K; Driscoll, Timothy A; Parikh, Suhag H; Page, Kristin M; Vinesett, Richard; Severyn, Christopher; Sung, Anthony D; Proia, Alan D; Jenkins, Kirsten; Arshad, Mehreen; Steinbach, William J; Seed, Patrick C; Kelly, Matthew S
Infections and graft-versus-host disease (GVHD) have historically resulted in high mortality among children undergoing umbilical cord blood transplantation (UCBT). However, recent advances in clinical practice have likely improved outcomes of these patients. We conducted a retrospective cohort study of children (<18years of age) undergoing UCBT at Duke University between January 1, 1995 and December 31, 2014. We compared 2-year all-cause and cause-specific mortality during 3 time periods based on year of transplantation (1995 to 2001, 2002 to 2007, and 2008 to 2014). We used multivariable Cox regression to identify demographic and UCBT characteristics that were associated with all-cause mortality, transplantation-related mortality, and death from invasive aspergillosis after adjustment for time period. During the 20-year study period 824 children underwent UCBT. Two-year all-cause mortality declined from 48% in 1995 to 2001 to 30% in 2008 to 2014 (P = .0002). White race and nonmalignant UCBT indications were associated with lower mortality. Black children tended to have a higher risk of death for which GVHD (18% versus 11%; P = .06) or graft failure (9% versus 3%; P = .01) were contributory than white children. Comparing 2008 to 2014 with 1995 to 2001, more than half (59%) of the reduced mortality was attributable to a reduction in infectious mortality, with 45% specifically related to reduced mortality from invasive aspergillosis. Antifungal prophylaxis with voriconazole was associated with lower mortality from invasive aspergillosis than low-dose amphotericin B lipid complex (hazard ratio, .09; 95% confidence interval, .01 to .76). With the decline in mortality from invasive aspergillosis, adenovirus and cytomegalovirus have become the most frequentinfectious causes of death in children after UCBT. Advances in clinical practice over the past 20years improved survival of children after UCBT. Reduced mortality from infections, particularly invasive aspergillosis, accounted for the largest improvement in survival and was associated with use of voriconazole for antifungal prophylaxis.
Open Access
Richard Dadd and the Fairy Feller's Master-Stroke.
(The American journal of psychiatry, 2015-11) Davidson, Jonathan
Open Access
Steep increase in best-practice cohort life expectancy.
(Popul Dev Rev, 2011) Shkolnikov, Vladimir M; Jdanov, Dmitri A; Andreev, Evgeny M; Vaupel, James W
We analyze trends in best-practice life expectancy among female cohorts born from 1870 to 1950. Cohorts experience declining rather than constant death rates, and cohort life expectancy usually exceeds period life expectancy. Unobserved mortality rates in non-extinct cohorts are estimated using the Lee-Carter model for mortality in 1960–2008. Best-practice cohort and period life expectancies increased nearly linearly. Across cohorts born from 1870 to 1920 the annual increase in cohort length of life was 0.43 years. Across calendar years from 1870 to 2008, the annual increase was 0.28 years. Cohort life expectancy increased from 53.7 years in the 1870 cohort to 83.8 years in the 1950 cohort. The corresponding cohort/period longevity gap increased from 1.2 to 10.3 years. Among younger cohorts, survival to advanced ages is substantially higher than could have been anticipated by period mortality regimes when these cohorts were young or middle-aged. A large proportion of the additional expected years of life are being lived at ages 65 and older. This substantially changes the balance between the stages of the life cycle.
Open Access
The annual ASCI meeting: does nostalgia have a future?
(J Clin Invest, 2008-04) Lefkowitz, Robert J
For many academic physician-scientists, the yearly Tri-Societies meeting of the ASCI, AAP, and AFCR during the 1960s, '70s, and '80s was an annual rite of spring and the focal point of the academic year. In this brief essay, I set down some miscellaneous recollections of these meetings and some thoughts about why they were of such central importance in the careers of those of my generation.
Open Access
The music of war: Seven World War 1 composers and their experience of combat.
(Journal of medical biography, 2018-11) Davidson, Jonathan Rt
The effect of World War 1 military service on composers has been neglected in comparison with poets and artists. This article describes the wartime service of Arthur Bliss, Ralph Vaughan Williams, Ivor Gurney, EJ Moeran, Gordon Jacob, Patrick Hadley, and Maurice Ravel. The relationship between experiences of combat and the psychological health of these men is examined, with consideration being given to predisposition and possible causative influences of military service on their later careers, examined from individual and societal perspectives.
Open Access
The Wesselhoefts: A medical dynasty from the age of Goethe to the era of nuclear medicine.
(Journal of medical biography, 2017-11) Davidson, Jonathan Rt
For six generations, members of the Wesselhoeft family have practiced medicine in Germany, Denmark, Switzerland, Canada and/or the USA. In the early decades of the 19th century, two Wesselhoeft brothers left Europe to eventually settle in New England, where they and their progeny gave rise to a regional medical dynasty. The Wesselhoeft doctors became well-known practitioners of homeopathy, hydropathy, conventional medicine and surgery, in academic and general clinical settings. An additional connection was established to the literary worlds of Germany and the USA, either through friendships or as personal physicians.
Open Access
Threading the needle: when embroidery was used to treat shell-shock.
(Journal of the Royal Army Medical Corps, 2018-09) Davidson, Jonathan
Open Access
When Women and Children Made the Policy Agenda - The Sheppard-Towner Act, 100 Years Later.
(The New England journal of medicine, 2021-11-06) Baker, Jeffrey P