Growth in Afro-Caribbean slave populations

Height data for African slave populations in Trinidad, Guyana and other British Caribbean colonies in the early nineteenth century are analyzed and compared with Cuban and United States slave populations. Slaves born in Trinidad and Cuba achieved final heights greater than their African-born parents, but those born in Guyana were shorter. Afro-Caribbean slaves living in sugar-producing colonies showed inferior growth compared to those living in colonies based on less arduous forms of economic activity, such as the Bahamas and Bermuda. The latter groups achieved heights similar to those of the United States slaves. Menarche occurred in the United States about 2 years earlier than in Trinidad. These differences in growth cannot be explained adequately by genetic variations in growth potential or by heterosis, but were a result of differences in nutrition, infection and work regime. Superior growth was associated with high rates of natural increase, whereas apparent stature reduction occurred in slave populations subject to the heaviest mortality. Modern Afro-Caribbean adult populations are about 10 cm taller than their genitor slave populations.     

Growth responses of barley seedling to simulated weightlessness induced by two-axis rotation

Summary A device used for simulated weightless studies is described and is called the Nogravatron. The Nogravatron apparatus produces simulated weight-lessness by rotating seedlings simultaneously at the rate of 0.25 rpm and 1.0 rpm in two axes perpendicular to each other. Atlas barley seedlings grown on the apparatus grew at rates different from that of stationary controls. Coleoptile elongation in rotated barley was not inhibited by light during the first 55 hours of rotation treatment whereas stationary controls were photoinhibited. After 55 hours the growth of rotated coleoptiles was inhibited by light. The coleoptiles did not show movements and were oriented along the longitudinal axis of the seed. Roots also did not show geotropic movements but the growth direction was affected by the proximity of other roots. Coleoptiles rotated in dark were significantly longer than stationary controls on the third and fourth day but not so on the fifth day and later. Coleoptiles rotated in light were about 35 percent longer than the stationary coleoptiles by the third day and maintained this significant difference to the end of the experiment.Supported in part by NASA Grant NsG 538-63 and by Air Force Office of Scientific Research Office of Aerospace Research, United States Air Force, Contract No. AF 49 (638)-1387.     

A mathematical interpretation of motor reactions to fixed and moving stimulation of the eye

The results of experiments performed by L.S. Stone and by R. W. Sperry on vision in salamanders are analyzed. A summary of Reichardt's theory, which originated in the researches of B. Hassenstein on insects, is given, and an application to salamanders is carried out. Introducing a simpler mathematical development based on the onefactor theory of excitation, the same formal results are obtained. A complete model, which includes those results and tries to fit the salamander behavior described by stone, is elaborated and translated into Boolean terms. As a complementary consideration, it is pointed out that the functional rigidity of the visuomotor system, deriving from a biological molecular hysteresis, could be framed in theneuro-affinity principle, the spatial expression of which would turn out to be abiological field. This research was supported by the United States Air Force through the Air Force Office of Scientific Research of the Air Research and Development Command under Contract No. AF 18(600)-1454. Reproduction in whole or in part is permitted for any purpose of the United States Government.     

An avoidance learning situation. A neural net model

A simple avoidance situation is considered in terms of a neural net learning model. Data for the control situation can be represented by an expression having three parameters which determine the initial and the steady state activities together with the transient aspects. The introduction of a learning parameter then allows one to calculate satisfactorily the results obtained in the experimental situation in which shock is applied. This research was supported in part by the United States Air Force through the Air Force Office of Scientific Research of the Air Research Development Command under Grant No. AF AFOSR 370-63 and in part by the United States Public Health Service Grant RCA GM K6 18,420.     

Plasticity,political economy,and physical growth status of Guatemala Maya children living in the United States

Migration of Maya refugees to the United States since the late 1970s affords the opportunity to study the consequences of life in a new environment on the growth of Maya children. The children of this study live in Indiantown, Florida, and Los Angeles, California. Maya children between 4 and 14 years old (n = 240) were measured for height, weight, fatness, and muscularity. Overall, compared with reference data for the United States, the Maya children are, on average, healthy and well nourished. They are taller and heavier and carry more fat and muscle mass than Maya children living in a village in Guatemala. However, they are shorter, on average, than children of black, Mexican-American, and white ethnicity living in Indiantown. Children of Maya immigrants born in the United States tend to be taller than immigrant children born in Guatemala or Mexico. Families that invest economic and social resources in their children tend to have taller children. More economically successful families have taller children. Migration theory and political economy theory from the social sciences are combined with plasticity theory and life history theory (parental investment) from biology to interpret these data. Am J Phys Anthropol 102:17–32, 1997. © 1997 Wiley-Liss, Inc.     

Environmental objections to the PAVE PAWS radar system: a scientific review

As part of our continental defense system, the United States Air Force has operated a radar system, known generally by the label PAVE PAWS, off of Cape Cod, MA since 1978. Some populated areas in the vicinity of the system are subject to a low level of background radiofrequency radiation from the system, and local citizens' groups have expressed concern that this radiofrequency radiation may affect their health. These concerns have been fueled by presentations and letters by Dr. R. A. Albanese, an applied mathematician at the Air Force Research Laboratory, who has proposed standards by which that PAVE PAWS radiofrequency radiation which is incident on populations should be judged. I discuss those standards that are sufficiently well defined to be subject to analysis and show that they are not based on sound quantitative reasoning.     

Are birth defects among Hispanics related to maternal nativity or number of years lived in the United States?

BACKGROUND: Literature on the risk of birth defects among foreign‐ versus U.S.–born Hispanics is limited or inconsistent. We examined the association between country of birth, immigration patterns, and birth defects among Hispanic mothers. METHODS: We used data from the National Birth Defects Prevention Study and calculated odds ratios (ORs) and 95% confidence intervals and assessed the relationship between mothers' country of birth, years lived in the United States, and birth defects among 575 foreign‐born compared to 539 U.S.–born Hispanic mothers. RESULTS: Hispanic mothers born in Mexico/Central America were more likely to deliver babies with spina bifida (OR = 1.53) than their U.S.–born counterparts. Also, mothers born in Mexico/Central America or who were recent United States immigrants (≤5 years) were less likely to deliver babies with all atrial septal defects combined, all septal defects combined, or atrial septal defect, secundum type. However, Hispanic foreign‐born mothers who lived in the United States for >5 years were more likely to deliver babies with all neural tube defects combined (OR = 1.42), spina bifida (OR = 1.89), and longitudinal limb defects (OR = 2.34). Foreign‐born mothers, regardless of their number of years lived in the United States, were more likely to deliver babies with anotia or microtia. CONCLUSIONS: Depending on the type of birth defect, foreign‐born Hispanic mothers might be at higher or lower risk of delivering babies with the defects. The differences might reflect variations in predisposition, cultural norms, behavioral characteristics, and/or ascertainment of the birth defects. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.     

Identifying a cohort of US twins using Social Security Administration records.

A sample of pairs of twins who were born in the United States in 1919 and survived to adulthood is identified through an innovative and large-scale application of the methodology of probabilistic linkage. The social security program began in the United States in November 1936, and the file of applicants for a social security number - which was used in this study - is the closest thing in the United States to a population register. The study results are very satisfactory, and demonstrate the superiority of probabilistic linkage to exact linkage. We estimate that about 33,000 twin pairs were born in the United States in 1919 and about 19,000 survived to age 17. Since the social security number was not then, at the inception of the program, the universal identifier that it is today, the number of enumerated twin pairs is somewhat less. Nonetheless, over 16,000 twin pairs can be identified by the method of probabilistic linkage. By comparison, only about half as many can be identified by straightforward exact linkage.     

Biodemography of exceptional longevity: early-life and mid-life predictors of human longevity

This study explores the effects of early-life and middle-life conditions on exceptional longevity using two matched case-control studies. The first study compares 198 validated centenarians born in the United States between 1890 and 1893 to their shorter-lived siblings. Family histories of centenarians were reconstructed and exceptional longevity validated using early U.S. censuses, the Social Security Administration Death Master File, state death indexes, online genealogies, and other supplementary data resources. Siblings born to young mothers (aged less than 25 years) had significantly higher chances of living to 100 compared to siblings born to older mothers (odds ratio = 2.03, 95% CI = 1.33-3.11, p = .001). Paternal age and birth order were not associated with exceptional longevity. The second study explores whether people living to 100 years and beyond differ in physical characteristics at a young age from their shorter-lived peers. A random representative sample of 240 men who were born in 1887 and survived to age 100 was selected from the U.S. Social Security Administration database and linked to U.S. World War I civil draft registration cards collected in 1917 when these men were 30 years old. These validated centenarians were then compared to randomly selected controls who were matched by calendar year of birth, race, and place of draft registration in 1917. Results showed a negative association between "stout" body build (being in the heaviest 15 percent of the population) and survival to age 100. Having the occupation of "farmer" and a large number of children (4 or more) at age 30 increased the chances of exceptional longevity. The results of both studies demonstrate that matched case-control design is a useful approach in exploring effects of early-life conditions and middle-life characteristics on exceptional longevity.     

Effects of a synchronizer phase-shift on circadian rhythms in response of mice to ethanol or ouabain

The percentage of mice dying from a toxic dose of ethanol or ouabain was determined at 4-hour intervals during the first 3 days after inversion of an LD(12:12) lighting regimen. In comparison to unshifted control animals at similar stages of the synchronizer schedule, spans of relative advantage alternated with spans of relative disadvantage due to a gradual phase-shift of the circadian susceptibility rhythm. Overall mortality, determined for an integral number of day, was not obviously affected by the regimen-shift.Supported by grants from the United States Public Health Service (5-K6-GM-13,981), NASA (NGR-24-005-006) and the U.S. Air Force (F29600-69-C-0011).     

Research on alpine isolates in Switzerland

This study explores the effects of early-life and middle-life conditions on exceptional longevity using two matched case-control studies. The first study compares 198 validated centenarians born in the United States between 1890 and 1893 to their shorter-lived siblings. Family histories of centenarians were reconstructed and exceptional longevity validated using early U.S. censuses, the Social Security Administration Death Master File, state death indexes, online genealogies, and other supplementary data resources. Siblings born to young mothers (aged less than 25 years) had significantly higher chances of living to 100 compared to siblings born to older mothers (odds ratio = 2.03, 95% CI = 1.33–3.11, p = .001). Paternal age and birth order were not associated with exceptional longevity. The second study explores whether people living to 100 years and beyond differ in physical characteristics at a young age from their shorter-lived peers. A random representative sample of 240 men who were born in 1887 and survived to age 100 was selected from the U.S. Social Security Administration database and linked to U.S. World War I civil draft registration cards collected in 1917 when these men were 30 years old. These validated centenarians were then compared to randomly selected controls who were matched by calendar year of birth, race, and place of draft registration in 1917. Results showed a negative association between “stout” body build (being in the heaviest 15 percent of the population) and survival to age 100. Having the occupation of “farmer” and a large number of children (4 or more) at age 30 increased the chances of exceptional longevity. The results of both studies demonstrate that matched case-control design is a useful approach in exploring effects of early-life conditions and middle-life characteristics on exceptional longevity.     

Maternal nativity status and pregnancy outcome among U.S.‐born Filipinos

Abstract

Using 1979–87 Hawaii vital record data on single live births, this study compares by nativity status of the mother the maternal characteristics and pregnancy outcomes of resident Filipino women. Among ethnic minorities in the United States, the pregnancy outcomes of U.S.‐born mothers have been reported to compare unfavorably to their foreign‐born counterparts. In this study, unequivocally preferential pregnancy outcome indicators were not observed for foreign‐born women. Contrary to expectations, a significant, but modest, increase in the risk of preterm delivery was found for infants of Philippines‐born mothers, along with a less favorable mean birth weight and gestational age. As a growing minority population in the United States, the atypical determinants and patterns of pregnancy outcome in this population warrants further investigation.     

Towards a virtual reality for plant-associated fungi in the United States and Canada

At present knowledge of fungal biodiversity in North America is scattered in diverse sources ranging from well-reviewed, comprehensive databases to unedited databases of reports from the literature, information on file cards, and uncomputerized reference collections. Resources available electronically were used to determine their relative importance in evaluating the plant-associated fungi known from the United States and to a lesser extent Canada. The results demonstrate that the literature provides the greatest information but that reference collections in the US National Fungus Collections contribute between 22–31% additional data. Little overlap exists between fungi isolated as endophytes and those reported in the literature or as reference collections. Eighty to 100% of the plant-associated fungi reported from Canada are accounted for in comprehensive resources for the United States. A comprehensive database of plant-associated fungi in Canada, the United States, and eventually Mexico would serve as a valuable resource for those making plant quarantine decisions.     

Tuberculosis chemoprophylaxis.

The incidence of tuberculosis in the United States, after decreasing for many years, has recently begun to climb at an alarming rate. This rise is due mainly to excess cases in high-risk groups including human immunodeficiency virus-infected patients, the elderly, the foreign born, and the homeless. In the United States tuberculosis has been associated with a 10% mortality despite adequate treatment. The tuberculin skin test is a safe and inexpensive test for detecting tuberculous infection. To improve its predictive value the diagnostic criteria for classifying a positive reaction have recently been revised. High-risk populations should be screened to identify those persons who would most benefit from preventive treatment. Isoniazid therapy taken for 6 to 12 months is a safe and highly effective means of preventing tuberculous infection from developing into active disease. The most worrisome toxicity of isoniazid, fatal hepatitis, is extremely rare; when patients are monitored closely the incidence of death from hepatotoxicity is less than 0.01%.     

Legal and policy issues for animal assisted interventions with special populations

In order to protect themselves and their animals, persons involved in animal-assisted interventions, as well as those providing therapeutic interventions involving animals and those seeking to study such situations should understand when a law provides a right to be accompanied by an assistance or service animal. Using applicable federal laws in the United States, this article defines service, assistance, and therapy animals and analyzes the circumstances under which persons utilizing these animals have the legal right of access to public places and housing. The article also discusses the intersection of federal, state, and local law in the United States and provides ways state and local laws may provide for greater access for persons accompanied by service, assistance, and therapy animals.     

Bombing and Sonoran Pronghorn: A Clear and Present Danger?

ABSTRACT The United States Air Force (USAF) uses part of Sonoran pronghorn (Antilocapra americana sonoriensis) habitat for bombing exercises (i.e., Barry M. Goldwater Air Force Range [BMGR], southwest AZ, USA) that could be detrimental to the endangered subspecies. To minimize injury or death to Sonoran pronghorn, the USAF and United States Fish and Wildlife Service developed a monitoring protocol that would eliminate live ordnance delivery in the vicinity of pronghorn. From 1998 to 2003, we searched for pronghorn on or near military targets prior to ordnance delivery. If we observed pronghorn within 5 km of a target, the target was closed for ≥24 hours. We monitored bombing ranges on BMGR and closed >5,000 targets for >1,000 days due to military activity. To our knowledge, no pronghorn were killed or injured. We recommend that the monitoring program continue as long as military activity occurs in pronghorn habitat.     

On visual adaptation: II. The electroretinogram and the bipolar cells

First a model for theb-wave of the electroretinogram is given. The essential part of the model is the diffusion into the rod-bipolar synapse of a transmitter substance, followed by the induction of an inhibitor. Making use of this model, adaptation to an illumination too weak to cause of significant decrease in the concentration of visual pigment is interpreted as due to a decreased effectiveness of the rod impulse in exciting the bipolar cell. The disparity between threshold changes for very small test spots and for relatively large spots is explained simply, without invoking any additional physiological mechanisms. This research was supported in part by the United States Air Force through the Air Force Office of Scientific Research of the Air Research Development Command under Contract No. AF(638)-414 and in part by the United States Public Health Service Training Grant 2G-833.     

On the interpretation of the effect of area on the critical flicker frequency

The effects of area and intensity on the critical flicker frequency, threshold, and reaction time are considered in terms of neural net theory. An attempt is made to develop a mechanism which can account for the phenomena associated with the empirically observed laws of Ricco, Granit, Talbot, and Ferry-Porter as well as observations on reaction time and threshold. A simple model gives results which are substantially in agreement with observation except for a few apparent discrepancies. Experimental procedures are suggested which can determine whether these are apparent or real. This research was supported by the United States Air Force through the Air Force Office of Scientific Research of the Air Research and Development Command under contract No. AF 18(600)-1454. Reproduction in whole or in part is permitted for any purpose of the United States Government.     

Amebic liver abscess: epidemiology, clinical features, and outcome

Amebic liver abscess (ALA) is a serious, but readily treatable form of hepatic infection. In order to understand the clinical features of this condition in the United States, we reviewed the medical histories of 56 patients with ALA at two large San Francisco Hospitals from 1979 to 1994. Patients were divided into the following groups based on the presumed manner in which they had acquired ALA: those born or raised in the United States, with a history of travel to an endemic area (Tr-ALA); those from an endemic area, but living in the United States for less than one year (En-ALA); and those neither from nor having traveled to an endemic area (N-ALA). We found distinct clinical patterns in patients from different epidemiological groups. Patients with Tr-ALA were a decade older than those from endemic regions, were more likely to be male, and tended to have an insidious onset. Furthermore, compared to patients with En-ALA, those with Tr-ALA were more likely to have hepatomegaly (P < 0.0001) and large abscesses (ALA > 10 cm; P < 0.01). One third of the patients studied had no associated travel history or endemic origin as risk factors. Of these, 63% had a condition consistent with severe immunosuppression, such as infection with the human immunodeficiency virus (HIV), malnourishment with severe hypoalbuminemia, or chronic infection. In patients with N-ALA, the presence of a presumed immunosuppressed state increased significantly, as compared to patients with endemic or travel risk factors for ALA. During the last five years of the study, one third of all patients diagnosed with ALA were HIV positive (including 2 with a new diagnosis of AIDS), many of whom were discovered to be HIV-infected only after presentation with ALA. We conclude that travel to and origin in an endemic area are important risk factors for the development of ALA, and patients in these different epidemiological groups appear to have distinct clinical features. Further, in the absence of recognized risk factors, the development of ALA may suggest an immunocompromised host.     

Does Mortality Vary between Asian Subgroups in New Zealand: An Application of Hierarchical Bayesian Modelling

The aim of this paper was to see whether all-cause and cause-specific mortality rates vary between Asian ethnic subgroups, and whether overseas born Asian subgroup mortality rate ratios varied by nativity and duration of residence. We used hierarchical Bayesian methods to allow for sparse data in the analysis of linked census-mortality data for 25–75 year old New Zealanders. We found directly standardised posterior all-cause and cardiovascular mortality rates were highest for the Indian ethnic group, significantly so when compared with those of Chinese ethnicity. In contrast, cancer mortality rates were lowest for ethnic Indians. Asian overseas born subgroups have about 70% of the mortality rate of their New Zealand born Asian counterparts, a result that showed little variation by Asian subgroup or cause of death. Within the overseas born population, all-cause mortality rates for migrants living 0–9 years in New Zealand were about 60% of the mortality rate of those living more than 25 years in New Zealand regardless of ethnicity. The corresponding figure for cardiovascular mortality rates was 50%. However, while Chinese cancer mortality rates increased with duration of residence, Indian and Other Asian cancer mortality rates did not. Future research on the mechanisms of worsening of health with increased time spent in the host country is required to improve the understanding of the process, and would assist the policy-makers and health planners.