Non-lethal weapons technologies--the case for independent scientific analysis

Various technologies have been proposed for non-lethal weapons (NLW), some of them credible, or at least plausible, but strong claims were made for others without evidence or references. Five such technologies are examined. For the chemical and biological examples, detailed information is lacking but the diminishing number of such claims over time and general scientific knowledge suggest that fulfilment of the promises is improbable. For acoustic weapons, a detailed study found that many of the claims are plainly untrue. In this case, even wrong values for physiological thresholds were presented. Civil and military NLW programmes in the USA put their main emphasis on simple, short-term technologies rather than exotic ones. In order to avoid dangers arising from unrealistic promises, the concept of preventive arms control should be applied to NLW. Its first step is a scientific analysis, investigating the new weapons, the propagation of their effects and the effect on the targets. Such detailed studies are needed for each proposed NLW technology.

Immigration and hybridization patterns of yellow and anubis baboons in and around Amboseli, Kenya

In 1986, Samuels and Altmann reported evidence for a hybrid zone between Papio anubis and Papio cynocephalus in Amboseli, Kenya, in a baboon population that has been the subject of long-term study since 1971 [Samuels & Altmann, International Journal of Primatology 7:131-138, 1986]. In the current report we document ongoing patterns of hybridization in Amboseli between anubis and yellow baboons. In July 2000, we exhaustively scored living members of study groups for their degree of hybridity, using seven phenotypic characteristics (five in juveniles). We also scored all former members of study groups on the basis of photographic records, field notes, and observer recollections. A total of five anubis males and 11 males with hybrid phenotypes have immigrated into study groups over the course of the long-term study, and immigrations by hybrid males have increased in frequency over time. Further, the increasing frequency of hybrid phenotypes among animals born into study groups indicates that anubis and hybrid males have successfully reproduced in study groups. However, hybrid phenotypes and anubis immigrations were limited to groups in the southwestern portion of the Amboseli basin, with no hybrids occurring in the six eastern groups. Finally, we present evidence that anubis and hybrid males in Amboseli exhibit patterns of natal dispersal that are different from those of yellow males in Amboseli: males with anubis or hybrid phenotypes were significantly more likely to immigrate as juveniles or young subadults than were yellow males.

Cross-species amplification, non-invasive genotyping, and non-Mendelian inheritance of human STRPs in Savannah baboons

Twenty-nine human microsatellite primer pairs were screened for their utility in the cross-species amplification of baboon DNA derived from both blood and feces as part of a larger study to identify paternal half sisters in a population of wild baboons (Papio cynocephalus). Forty-one percent (12/29) of the human primers successfully amplified baboon DNA. Of these 12 primers, six amplified fragments that were both polymorphic and heterozygous (mean number of alleles = 6, mean heterozygosity = 87%) and yielded repeatable results. However, only five of these six simple tandem repeat polymorphisms (STRPs) showed patterns of Mendelian inheritance (i.e., mothers and offspring shared at least one allele at each locus), and were therefore useful for determining relatedness between individuals. Analysis of the sixth primer revealed non-Mendelian inheritance, i.e., three of the six known mother-daughter pairs had no shared alleles. This failure was probably due to non-specific fragment amplification, and may have resulted from a different STRP locus being amplified in mother and daughter. This finding highlights the importance of sampling DNA from known parent-offspring pairs when screening microsatellite primers for genetic studies. Multiple, independent replications of genotypes and Mendelian checks are both particularly important when using cross-species amplification or when using a low-quality source of DNA.

Impact of injection rate on the Thrombolysis in Myocardial Infarction (TIMI) trial frame count

A mechanical injection was used to determine the impact of injection rate on the TIMI frame count. The 1.0-ml/s increase in hand injection rates from the 10th to 90th percentiles for angiographers is associated with a minor decrease of <2 frames that is <7% of the corrected TIMI frame count.

Coronary artery injection technique: a quantitative in vivo investigation using modern catheters

To date, there have been no quantitative in vivo assessments of contrast volumes and injection rates using modern high flow catheters during coronary angiography. Contrast volumes (n = 554), injection durations (n = 563), and injection rates (n = 498) were collected during 88 cardiac catheterizations. With increasing cathetersize (6, 7, and 8 French), injection volume increased (P < 0.0001), duration decreased (P < 0.0001), and rate increased (P < 0.0001). Compared with injections into the right coronary artery, left coronary artery injections were larger (7.1 +/- 0.1 cc vs. 4.8 +/- 0.1 cc, p < 0.0001), longer (3.6 +/- 0.05 sec vs 3.0 +/- 0.07 sec, P < 0.0001) and faster (2.1 +/- 0.04 cc/sec vs. 1.7 +/- 0.06 cc/sec, P < 0.0001). Patients with a significant stenosis in the left main or proximal right coronary artery received less contrast (P < 0.0001) more slowly (P < 0.0001) over a similar duration of injection (P = NS). When collaterals arose from the injected artery, angiographers injected more contrast (P < 0.001) over a longer period (P < 0.0001) more slowly (P < 0.0001). Catheter size and the injected vessel's location and anatomy significantly affect coronary catheterization injection technique.

Hypercortisolism associated with social subordinance or social isolation among wild baboons

BACKGROUND

The phenomena of basal hypercortisolism and of dexamethasone resistance have long intrigued biological psychiatrists, and much is still unknown as to the causes and consequences of such adrenocortical hyperactivity in various neuropsychiatric disorders. We have analyzed basal cortisol concentrations and adrenocortical responsiveness to dexamethasone in a population of wild baboons living in a national park in Kenya. We tested whether social subordinance in a primate is associated with dexamethasone resistance. Furthermore, we examined whether individual differences in adrenocortical measurements were predicted by the extent of social affiliation in these animals.

METHODS

Seventy yellow baboons (Papio cynocephalus) were anesthetized and injected with 5 mg of dexamethasone; the cortisol response was monitored for 6 hours. The animals were of both sexes in a range of ages and had known ranks in the dominance hierarchies within their troops. Extensive behavioral data were available for a subset of 12 adult males who were anesthetized under circumstances that also allowed for the determination of basal cortisol concentrations.

RESULTS

The socially subordinate baboons were less responsive to dexamethasone than were the dominant ones; as one manifestation of this, postdexamethasone cortisol values were more than 3 times higher in the dozen lowest-ranking animals compared with the dozen highest. In addition, socially isolated males had elevated basal cortisol concentrations and showed a trend toward relative dexamethasone resistance.

CONCLUSIONS

Our findings indicate that social status and degree of social affilitation can influence adrenocortical profiles; specifically, social subordinance or social isolation were associated in our study with hypercortisolism or feedback resistance.

Behavioural risk factors in the reproduction of inbred and outbred oldfield mice

The present study investigated two rarely measured aspects of inbreeding depression: the relationship between inbreeding and behaviour, and the possibility that inbred individuals that survive infancy may still suffer from inbreeding depression by failing to breed or failing to show appropriate mating or parental behaviours. Specifically, the relationship between (1) behaviour at pairing and reproductive success, (2) inbreeding and reproductive success and (3) inbreeding and pairing behaviour, was examined in two subspecies of the oldfield mouse, Peromyscus polionotusEffects of parental and offspring inbreeding were separated through experimental design and analysis. Activity level during the first 25 days after pairing predicted future reproductive success: pairs that remained less active during the nocturnal (active) period were significantly less likely to breed than pairs that remained more active. Inbred females took significantly longer to produce their first litters and were less likely to produce litters than were outbred females, independently of whether females were related to their mates (i.e. whether their offspring would be inbred). Inactive pairs averaged fewer surviving pups than did active pairs. Inbreeding coefficient of female was a significant predictor of activity level in one of the two subspecies, suggesting that inbreeding may affect behaviour. Inbred adult females showed inbreeding depression in the form of lower conception rates and fewer surviving offspring, although the specific traits affected differed for the two subspecies. The implications for captive breeding programs, and likely causes of the subspecific differences, are discussed.

Behavior predicts genes structure in a wild primate group

The predictability of genetic structure from social structure and differential mating success was tested in wild baboons. Baboon populations are subdivided into cohesive social groups that include multiple adults of both sexes. As in many mammals, males are the dispersing sex. Social structure and behavior successfully predicted molecular genetic measures of relatedness and variance in reproductive success. In the first quantitative test of the priority-of-access model among wild primates, the reproductive priority of dominant males was confirmed by molecular genetic analysis. However, the resultant high short-term variance in reproductive success did not translate into equally high long-term variance because male dominance status was unstable. An important consequence of high but unstable short-term variance is that age cohorts will tend to be paternal sibships and social groups will be genetically substructured by age.

Senescent decline in serum dehydroepiandrosterone sulfate concentrations in a population of wild baboons

The physiologic functions of dehydroepiandrosterone sulfate (DS), a precursor of androgens and estrogen and the most abundant steroid in the circulation, are unknown. Nevertheless, numerous studies have shown that low concentrations of DS are correlated with a variety of metabolic and cardiovascular diseases in human beings, and administration of DS to experimental animals is associated with protection from similar diseases. Thus, the marked decline in DS concentrations with age in human beings may be of considerable functional significance. However, because of the difficulties in studying any heterogeneous human population, it has been difficult to assess the extent to which the DS decline with age is confounded by any of a number of factors (e.g., smoking, level of activity, genetics, diet, medication and disease). We studied the effects of age on DS concentrations in a well-characterized population of wild yellow baboons living freely in a national park in East Africa. Study of these animals circumvents many of the confounds just noted. In examining animals ranging in age from juvenile status to old age, we observed a robust decline in DS concentrations with age. The magnitude of the decline is approximately equal in both sexes. In addition, the decline is similar in comparing two baboon groups which have fully natural diets with one group which forages heavily on garbage from people.

Periodontal health in free-ranging baboons of Ethiopia and Kenya

Frontal and lateral intraoral photographs of 19 baboons from the Awash National Park, Ethiopia and 37 baboons from Amboseli National Park, Kenya, were used to assess periodontal health. The Awash baboons, and two groups (Alto's and Hook's) at Amboseli, fed entirely from natural sources, but baboons from the third Amboseli group (Lodge) fed largely on food refuse from one of the park's lodges. Juveniles and adults were evaluated separately. Intraoral photographs were seriated based on visual appraisals of periodontal health. In both age groups, the best periodontal health was seen in Awash animals; Alto's and Hook's animals were intermediate, and the poorest health was seen in the Lodge sample. The periodontal health decreased with age in adult baboons, as reported in humans. Geochemistry, genetics, age, and diet (particularly variations in bacterial flora) were considered as factors contributing to the intergroup differences. Although it is not possible at present to exclude any of these as a contributing cause, we consider that diet in the broad sense (including food, water, and contamination by oral bacteria of human origin) probably plays a major role.

Sex-biased lactational duration in a human population and its reproductive costs

The authors tested the proposition that among humans (1) differences in lactational duration result in differences in costs of reproduction even under rich nutritional conditions; and (2) elimination of factors postulated to favor male-biased parental care will be reflected in elimination or reversal of sex-biased care. To do so, the authors examined the relationship between lactactational duration and fertility among Hutterites, a communal-living human population in which the levels of nutritional resources and fertility are high, breast feeding is the norm, contraceptive use is limited, and the collective social and economic system results in low resource variance among individuals. The authors demonstrate that even under good nutritional conditions, duration of nursing was a significant predictor of the length of time to next pregnancy and that nursing continued to suppress fertility after the resumption of menses. Moreover, the authors find that daughters were nursed longer than sons, leading to a longer interval to next pregnancy. The authors examine this uncommon, but not unique, finding of female-biased human parental care in the light of Hutterite social structure, and they explore the consistency of this finding with the most applicable models of parental investment.

Behavioral, endocrine, and immunological correlates of immigration by an aggressive male into a natural primate group

A very aggressive young adult male entered one of three long-term study groups of yellow baboons. Papio cynocephalus, approximately 3 weeks after an immobilization project began. The immigrant male's rate of agonistic encounters was appreciably higher than average, and these interactions disproportionately involved adult females as targets. Basal cortisol concentrations were higher and total lymphocyte counts lower for individuals immobilized during the immigration situation than for other individuals; these effects were greater for females than for males. Among animals whose endocrine data were obtained during the immigration period, some were specific targets of the immigrant male's aggression and others were not. Lymphocyte counts were significantly lower for those individuals who were victims of the male's aggression than for noninvolved individuals; a nonsignificant tendency toward higher basal cortisol concentrations for victims was observed as well. The immigrant male himself had a high basal cortisol concentration, a low lymphocyte count, and a testosterone concentration that was triple the average for adult males and almost double the second highest value in the population.

Incidence of hypercortisolism and dexamethasone resistance increases with age among wild baboons

While many features of the adrenocortical axis are unchanged with age in humans, there is a pattern of senescent hypercortisolism. This occurs basally, following threshold doses of dexamethasone, and in synergy with depression or Alzheimer's disease. An understanding of neuroendocrine aging is important, for both its gerontological implications, and determination of normative values for comparison with neuropsychiatric states. We have investigated whether aging is associated with hypercortisolism in a population of wild primates. The subjects were 108 yellow baboons (Papio cynocephalus) that have been under long-term study of Amboseli National Park in Kenya. Animals were anesthetized by blowgun under similar circumstances that allow for determination of basal cortisol concentrations. Sixty minutes later, 5.0 mg dexamethasone was administered to each animal, and cortisol determinations were made on serum collected immediately before administration and 6 hr later. Basal cortisol concentrations rose with age (p less than 0.028; r = 0.23). This occurred in a nonprogressive manner, in that there were no differences in concentrations among the youngest three quartiles of animals, whereas animals in the oldest quartile (older than approximately 16 years) had significantly higher values. In addition, there was a significant increase in postdexamethasone cortical concentrations with age (p less than 0.01; r = 0.31). This feature emerged progressively with age in both sexes. A number of possible artifactual causes of this senescent pattern could be eliminated, including medication confound, coincident disease, and body weight. These findings suggest that hypercortisolism and glucocorticoid feedback resistance might be general features of primate aging.

Corneal lathing using the excimer laser and a computer-controlled positioning system: Part II--Variable trephination of corneal buttons

A new system is presented that allows a variable trephination of donor corneas for the preparation of corneal buttons used in penetrating keratoplasty. With the help of a computer-controlled positioning system that uses high-precision micropositioning elements (both translation and rotational stages) the donor cornea is removed, epithelial side up, in a fixation device in front of a focused excimer laser beam (ArF, lambda = 193 nm). User friendly computer software allows the surgeon to select a variety of parameters (diameter, shape, angle of trephination) of the corneal graft. Histological and electron microscopical data of human corneas trephined with this "Excimer Laser Corneal Shaping System" are presented.

Corneal lathing using the excimer laser and a computer-controlled positioning system: Part I--Lathing of epikeratoplasty lenticules

Precise lathing of epikeratoplasty lenticules is difficult to achieve with the cryolathe due to unpredictable expansion of the lathing tools and the corneal tissue during the freezing process. In addition, the procedure destroys all viable cells in the transplant thereby possibly contributing to the prolonged period of visual rehabilitation. Non-freezing techniques using the microkeratome or the rotor-trephine, on the other hand, are technically demanding, can cause mechanical damage during cutting or fixation, and, have not given consistently reproducible refractive results. A new system is presented that allows a variable laser ablation of donor corneas into lenticules for aphakic and myopic epikeratoplasty, as well as for lamellar keratoplasty. With the help of a computer-controlled positioning system that uses high-precision micropositioning elements (both translation and rotational stages) the donor cornea is moved, epithelial side down, in a holding device in front of a focused excimer laser beam (ArF, lambda = 193 nm). This photoablation lathing process assures the viability of the stromal cells in the lenticule in close approximation to the treated surface. The user friendly computer software allows the fast and convenient selection of a variety of parameters, such as the diameter of the optical zone, the shape of the wing zone, the refractive power, the central thickness of the lenticule and the overall contour of the transplant. The first laboratory data of lenticules prepared from human corneas with this "Excimer Laser Corneal Shaping System" are presented.