Solution to pet overpopulation may involve change in perspective.
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Animals↗
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Perspectives on overpopulation.
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Developing Countries↗
Population explosion: the making of a vision.
The authors of the publication "Population Explosion: the Making of a Vision" state: "During our research in the US our goal was to find out how the problem of 'overpopulation' had become, or better said, been made universal following the Second World War. How was it possible that the view become consensus that population size is determined by state or internationally controlled economic variables and that the future of this planet depended upon an optimal control? Finally, how did contraception or the decision how many children a women bears become a political question? Better said, how did they become part of US foreign policy? Through our research we became acquainted with the development of the contraception of 'overpopulation,' from myth to scientific fact, from the perspective of those who were responsible for this evolution." This publication also includes the authors' conclusions of their study and 32 documents consulted by them. It is an interesting vision on how consensus is created.
Conservation of Natural Resources↗
Contraception: an overview.
In this century, paramount progress has been made in many areas of medicine, not least in the field of contraception, with landmarks such as the introduction of intrauterine contraceptive devices (IUDs), hormonal contraceptives (OCs), and laparoscopic sterilization. The general optimism of the 1960s about overcoming the problems of global overpopulation with these new tools has subsequently been replaced by growing concern about the risks of contraception in general and of OCs especially. It was not before the 1980s that the benefit-risk balance of hormonal contraception turned out to be much more favorable than was formerly suspected. The wide variation from country to country in the prevalence of contraceptive methods has economic, political, religious, sociological, educational, and legal rather than medical reasons. Former misjudgments have led to a ban on valuable tools such as the sequential regimen or the use of 17-acetoxyprogestogen analogues as components in OCs, or to a ban on the licensing of depot progestogens in some countries but not in others. The recent decision of U.S. firms to cease production and sale of IUDs for legal reasons is unique and hopefully will not be imitated elsewhere. Just after the introduction of oral contraception, tremendous inventive dynamics led to the discovery of several new contraceptive principles. Most of these have reached the stage of clinical application and are being used satisfactorily, at least in some parts of the world. Later contraceptive concepts are still in the stage of experimentation and no breakthrough appears to be directly ahead. If contraception means more than just meeting individual wants--if it is also to be an instrument for handling the increasing problems of overpopulation--then much more must be done to deepen our knowledge of reproductive physiology, to popularize efficient means of contraception, and to make them available to everyone. Otherwise, all efforts to improve health standards throughout the world according to the "WHO Global Strategy for Health for All by the Year 2000" will be in vain.
Contraception↗
Colonic crypt changes during adenoma development in familial adenomatous polyposis: immunohistochemical evidence for expansion of the crypt base cell population.
Familial adenomatous polyposis patients, who have a germline APC mutation, develop adenomas in normal-appearing colonic mucosa, and in the process usually acquire a mutation in the other APC allele as well. Nonetheless, the cellular mechanisms that link these initiating genetic changes with the earliest tissue changes (upward shift in the labeling index) in colon tumorigenesis are unclear. Based on the tenet that colorectal cancer originates from crypt stem cells (SCs) and on our kinetic modeling, we hypothesized that overpopulation of mutant colonic SCs is the missing link. Directly testing this hypothesis requires measuring changes in the size of the SC population, but specific markers for human colonic SCs are lacking. Hence, we used immunohistochemical mapping to study crypt base cells, of which SCs are a subset. Using colectomy specimens from 16 familial adenomatous polyposis and 11 control cases, we determined the topographic profiles of various cell populations along the crypt axis and the proportions of each cell type. In the formation of adenomatous crypts, the distribution of cells expressing crypt base cell markers (MSH2, Bcl-2, survivin) expanded toward the crypt surface and showed the greatest proportional increase (fivefold to eightfold). Cells expressing a marker for the upper crypt (p27(kip1)) shifted to the crypt bottom and showed the smallest increase. This suggests that: 1) during adenoma development, APC mutations cause expansion of the crypt base cell population, including crypt SCs; 2) SC overpopulation can explain the shifts in pattern of proliferative crypt cell populations in early colon tumorigenesis, and 3) mutant crypt SCs clonally expand to form colonic adenomas and carcinomas.
Adenoma↗
Hyperplastic vascular smooth muscle cells of the intrarenal arteries in angiotensin II type 1a receptor null mutant mice.
BACKGROUND: Angiotensin II (Ang II), which contracts vascular smooth muscle cells (VSMCs), has been reported to regulate VSMC growth. Recently formed transgenic mice without angiotensinogen or Ang II receptors showed vascular alterations. However, it is still unclear how their VSMCs alter. We explored the role of Ang II via the Ang II type 1a receptor (AT1a) in VSMCs in vivo using AT1a null mutant mice. METHODS: We analyzed the ultrastructure of the intrarenal arteries in AT1a null mutant mice that were homozygous for a targeted disruption of AT1a receptor gene using light and electron microscopy. RESULTS: The structural changes of the intrarenal arteries in AT1a null mutant mice showed the wall thickening, which in the interlobar, arcuate, and proximal interlobular arteries consisted of two additional populations of VSMCs, on the luminal and abluminal sides of the media. The luminal overpopulation of smooth muscle cells (SMCs) was arranged in a longitudinal direction separated by increased interposed elastic laminae. The abluminal overpopulation of SMCs ran in circumferential directions separated from the main population. The cytological structure of VSMCs in AT1a null mutant mice was smaller in size, contained more organelles for protein synthesis and secretion than in control mice, and had poorly developed contractile apparatus. CONCLUSIONS: The lack of AT1a signaling causes structural abnormalities in the renal vascular system and transforms the phenotype of VSMCs into cell proliferation, induces the escape of VSMCs from the circular mechanical integrity, and results in increased synthesis of extracellular matrices.
Animals↗
The Global Burden of Disease Study: a useful projection of future global health?
One major conclusion of the Global Burden of Disease Study (GBDS) is that the global burden of disease will not change significantly from 1990 to 2020, in developed regions, developing regions or as a whole. Using the disability-adjusted life year (DALY), the Study estimates the burden as a result of 107 diseases, accidents and their disabling sequelae, disaggregated with respect to cause, sex, age and geographical region. The basic data used to construct estimates are sparse, and the DALY as a tool has received many criticisms. It obscures the distribution of disease and its impact in terms of handicap, and includes several social and economic value judgements. This weakens its power as a guide for the rational allocation of health resources at any point in time. Does it have use in guiding future planning and preventive action? At a global level, exceeding ecological capacity primarily through relative overpopulation is likely to be the greatest threat to overall health, yet overpopulation is not considered as a risk factor in itself. This reflects the understanding of health as an issue of the individual rather than the community. Together with the productivity-orientated weighting of DALYs, the Study appears to be more concerned with cost-effectiveness of health interventions rather than their equity. This underlies the reservations of the World Health Organization regarding the Study's use as a rational tool in health policy.
Cost of Illness↗
Uniform shear flow in dissipative gases: computer simulations of inelastic hard spheres and frictional elastic hard spheres.
In the preceding paper, we have conjectured that the main transport properties of a dilute gas of inelastic hard spheres (IHSs) can be satisfactorily captured by an equivalent gas of elastic hard spheres (EHSs), provided that the latter are under the action of an effective drag force and their collision rate is reduced by a factor (1+alpha)/2 (where alpha is the constant coefficient of normal restitution). In this paper we test the above expectation in a paradigmatic nonequilibrium state, namely, the simple or uniform shear flow, by performing Monte Carlo computer simulations of the Boltzmann equation for both classes of dissipative gases with a dissipation range 0.5 < or = alpha < or = 0.95 and two values of the imposed shear rate a. It is observed that the evolution toward the steady state proceeds in two stages: a short kinetic stage (strongly dependent on the initial preparation of the system) followed by a slower hydrodynamic regime that becomes increasingly less dependent on the initial state. Once conveniently scaled, the intrinsic quantities in the hydrodynamic regime depend on time, at a given value of alpha, only through the reduced shear rate a*(t) is proportional to a/square root(T(t)), until a steady state, independent of the imposed shear rate and of the initial preparation, is reached. The distortion of the steady-state velocity distribution from the local equilibrium state is measured by the shear stress, the normal stress differences, the cooling rate, the fourth and sixth cumulants, and the shape of the distribution itself. In particular, the simulation results seem to be consistent with an exponential overpopulation of the high-velocity tail. These properties are common to both the IHS and EHS systems. In addition, the EHS results are in general hardly distinguishable from the IHS ones if alpha approximately > 0.7, so that the distinct signature of the IHS gas (higher anisotropy and overpopulation) only manifests itself at relatively high dissipations.
Journal Article↗
Impact of high-energy tails on granular gas properties.
The velocity distribution function of granular gases in the homogeneous cooling state as well as some heated granular gases decays for large velocities as f proportional to exp(-const x v). That is, its high-energy tail is overpopulated as compared with the Maxwell distribution. At the present time, there is no theory to describe the influence of the tail on the kinetic characteristics of granular gases. We develop an approach to quantify the overpopulated tail and analyze its impact on granular gas properties, in particular on the cooling coefficient. We observe and explain anomalously slow relaxation of the velocity distribution function to its steady state.
Journal Article↗
Observations of acoustic-wave-induced superluminescence in an argon plasma.
It is shown that in an argon discharge plasma it is possible to obtain overpopulation of certain electronic levels of atomic argon under the influence of acoustic waves. When the specified threshold is exceeded, then a superluminescence (in the form of light flashes) from the overpopulated electronic levels of atomic argon is observed.
Journal Article↗
Eight centuries of Madurese migration to East Java.
"Over the past eight centuries in Indonesia, a substantial and ceaseless stream of out-migration has been flowing from the tiny island of Madura, poor and overpopulated, to the slightly better-off, but just as overpopulated...island of Java. This out-migration to East Java of the Madurese--Indonesia's third largest ethnic group--is one of the group's most notable features. Over the centuries, this out-migration has taken diverse forms as it has responded to varied impetus and reflects Indonesia's diverse migratory currents, past and present. This article, which is the first to be done on the subject, explores a little known aspect of Madurese history and society."
Asia↗
Determinants of adoption and euthanasia of shelter dogs spayed or neutered in the university of california veterinary student surgery program compared to other shelter dogs.
Limited economic resources and pet overpopulation force animals shelters to consider euthanasia of adoptable animals every day. Veterinary medical schools can play a positive role in increasing pet adoption and combating overpopulation by providing free neutering for shelter animals. This retrospective cohort study illustrated that the cooperative efforts of a veterinary medicine surgical teaching program and local animal shelters decreases euthanasia of adoptable pets. At the University of California, Davis (UCD), shelter dogs are neutered by veterinary students and then returned to the shelter for adoption. The rates of adoption and euthanasia of the dogs neutered at UCD were contrasted with a comparison shelter group to determine the effect of pre-adoption neutering. The UCD-neutered dogs had a lower rate of euthanasia than the comparison shelter group at the shelters investigated. At Sacramento County Animal Care and Regulation, 73% of the UCD group but only 36% of the comparison group were adopted. At Yolo County Animal Services, 71% of the UCD group and 45% of the comparison group were adopted. The sex of an animal did not significantly affect the rate of euthanasia. Dogs that were predominantly pit bull, rottweiler, or chow chow breeds had higher rates of euthanasia than other breeds, independent of neuter status. Also, juveniles (less than one year old) had lower rates of euthanasia than adults, independent of neuter status. UCD adult dogs had lower rates of euthanasia than comparison adults. Post-surgical UCD dogs spent a longer average time in the shelter before adoption (15 days at Sacramento; 16 days at Yolo) than the comparison dogs (11 and 12 days, respectively). UCD dogs also spent a longer average time in the shelter before euthanasia (18 and 25 days, respectively) than the comparison dogs (13 days at both shelters). Lower probabilities of euthanasia for behavioral or medical reasons were found for UCD dogs than for the comparison dogs. The probability of euthanasia for reasons of space limitations increased with time in shelter for both groups. In this study, pre-adoption neutering increased adoptions without increasing the probability of medical or behavioral euthanasia.
Animals↗
Early-age neutering of dogs and cats in the United States (a review).
Prepubertal gonadectomy, often referred to as early-age neutering, has increased in popularity in the United States. The procedure is often used at animal care and control facilities, where puppies and kittens are neutered as early as 7 weeks of age or before adoption. Although the anaesthetic and surgical procedures appear to be safe, studies continue to evaluate the long-term effects on health and behaviour. Early-age neutering is one technique that is used to combat pet overpopulation, a problem whereby millions of unwanted healthy dogs and cats are euthanased each year. Although neutering animals is helpful in controlling pet overpopulation, other factors must be considered. In addition, many animals are relinquished to shelters when they show inappropriate behaviours, because owners and veterinarians are unable to modify animal behaviour. This review discusses early-age neutering in the United States, and includes the review of scientific studies that have evaluated this procedure in puppies and kittens. Early-age neutering does not stunt growth in dogs or cats (a once-held belief), but may alter metabolic rates in cats. The anaesthetic and surgical procedures are apparently safe for young puppies and kittens; morbidity is lower and recovery is faster than in adult animals. To date, adverse side effects are apparently no greater in animals neutered at early ages (7 weeks) than in those neutered at the conventional age (7 months).
Anesthesia↗
[Variability of the quantitative and qualitative traits of Aedes dorsalis mosquitoes from larval cultures of varying densities].
Larvae of Aedes dorsalis Mg. were maintained at the density of 0.05 and 0.5 spec./ml. It was noted that mosquitoes from overpopulated cultures grew smaller in size. The wings became shorter and more narrow by 4 to 6%. The wing reduction occurred on account of its distal elements (veins r3 and m2). Despite the decrease in the value of characters their variability decreased too, having increased only for wing width and vein mcu. In overpopulated cultures the wing length connection with veins r3 and m2 grew weaker in males while in females only such tendency was observed. Wing bilateral asymmetry was noted: left wing of females became wider and those of males wider and shorter. Analysis of variability of qualitative wing characters, which were singled out according to the venation pattern, has shown that of 9 studied characters only two depended on density (arrangement of corners of radial and medial vectors) and only in females. The role of such wing changes for swarming, active escaping from danger, direction and distance of flight of mosquitoes is discussed.
Aedes↗
A survey of attitudes toward responsible pet ownership.
The concerns of medical and community officials about responsible pet ownership have increased. Before a practical solution can be found for irresponsible ownership and community health problems associated with pet populations, the public's attitudes on issues related to responsible pet ownership must be determined. Such issues include attitudes on dog and cat overpopulation, potential public health problems associated with pet populations, and methods of controlling pet populations and stray animals. Responses to a questionnaire were used to evaluate the attitudes of 910 pet owners and nonowners toward factors comprising responsible pet ownership. The median age of the respondents was 33 years; 414 (45 percent) were men, and 496 (55 percent) were women. At the time of the study, 18 percent owned a cat and a dog, 35 percent owned only a dog, 11 percent showed only a cat, and 36 percent were nonowners. Not only the sex of the respondent but also the category of pet ownership affected opinions on overpopulation of dogs and cats, nuisance and pollution problems associated with these animals, and methods of controlling pet populations in the community. For example, owners agreed strongly on family planning for pets, but a majority of male owners stated that they would not have their dogs neutered.
Adolescent↗
[Clinical and etiologic study of 90 cases of chronic diarrhea].
90 patients with chronic diarrhoea underwent this prospective study. They were seen in a private hospital of Lima during 1990 and 1991. According to a methodologic plan for determining sources and the diseases that originate chronic diarrhoea. In all patients hematologic, bioquimic, coprocultures, coproparasitologic exams were done, chest and intestinal transit X-rays. All underwent duodenal content culture. Colon X-ray in 25 cases; proctosigmoidoscopy in 14 and upper digestive endoscopy in 19 patients. Abdominal echography in 12 and TAC in 2 cases. The final results showed as determinant diseases for chronic diarrhoea, according to their frequency: enteroparasitosis (23.3%), functional digestive disorders (20.0%), intestinal bacterial overpopulation (15.5%) of unknown origin (8.8%), colon diverticulus (7.7%) proven and probably (5.5%), lactose intolerance (3.3%), diabetes mellitus (2.2%), and in one case (1.1%) the following: intestinal linfoma, pancreas malignancy, AIDS, colonic and deformation and megaloblastic anemia. The causes of chronic diarrhoea are several and multifactorals and in this study we prove the preeminence of the intestinal parasitosis, functional disorders and intestinal bacterial overpopulation and with less frequency other pathologies.
Adolescent↗
Impacts of emigration on mountain watersheds: the upper Pokhara Valley, Nepal.
"Confronted with adverse physical conditions, marginal landholdings and scarce non-farming employment opportunities, farmers in the Upper Pokhara Valley had opted for temporary emigration as an alternative strategy for fulfilling their subsistence requirements. This had caused somewhat malign effects on watershed due to dwindling farm management practices and increasing dependency on common resources.... Findings of this study are envisaged to be conducive to the formulation of a comprehensive watershed management strategy, including population planning....[It is suggested] that both overpopulation and depopulation could be instrumental in watershed degradation, especially in mountainous areas where labor is a critical factor in the use and management of farmlands."
Agriculture↗