Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Carrying Capacity”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,603 records · Page 89Linked to original sources
PubMed1993

[The Chinese demographic challenge].

Recent official vital statistics data from China are used to emphasize the seriousness of the demographic situation in China, and to highlight the continued pressure on limited resources exerted by a growing population that is struggling to achieve socioeconomic development. The authors conclude that "the pessimistic scenarios of evolution of Chinese vital factors justify the pursuit, or even the intensification, of the birth control programme. New educational programmes should focus on the necessity to develop new solidarities, to achieve a [reasonable] vital growth at least during the next five decades, which could lead to a better balanced...development of the economy." (SUMMARY IN ENG)

Asia↗
PubMed1995

Population and resources in Mauritius.

"The island of Mauritius was facing a crisis by the 1950s as the relationship between its population and resources became unbalanced....A two-pronged strategy was set in place to change the relationship between population and resources. Firstly, an aggressive family-planning policy was established, reducing population growth. Secondly, the economy was diversified with tourism, financial services and, especially, manufacturing in the Mauritius Export Processing Zone, creating extra finance and resources. The changes have not been cost-free but Mauritius ends the century, not as a classic case of overpopulation, but more [as] a model micro-state that has overcome many population and resource problems, largely through its own efforts."

Africa↗
PubMed1995

NSSM 200 and the world population explosion.

This paper was published in the wake of Pope John Paul II's encyclical 'Evangelicum Vitae', which condemns abortion and contraception. The author describes how, in the mid-1970's, the Vatican blocked the implementation of President Nixon's 'National Security Study Memorandum 200', which was intended to combat global overpopulation. The author explains that excessive population growth is considered threatening to U.S. security interests, and concludes that "papal security-survival along with the influence of fundamentalist Protestant opposition to birth control is now pitted against the U.S. and world security-survival."

Americas↗
PubMed1975

[Comparative study of a group of mutant strains of Trichoderma viride, producer of cellulolytic enzymes].

In the course of selection of Trichoderma viride, the producer of cellulolytic enzymes, the group of mutant strains characterized by a higher level of productivity are isolate. It is shown that the isolated mutants possess a number of common but differing them from original strains characters. These include: the small size of colonies ("dwarfs"), a lower capacity to carry out some biochemical reactions, and increased development rate and a higher resistance to lethal effect of nitrosoguanidine and nitrosoethyl urea. The data obtained indicate that in the series of populations of successively isolated mutants observed the stabilization of variability of the levels of C1 enzyme synthesis takes place. It is also shown that, unlike original cultures, the populations of mutant strains are characterized by a higher variability of Cx enzyme activity levels as compared with C1.

Cellulase↗
PubMedDate not supplied

[Rivastigmine: a review of its clinical effectiveness].

The progression of Alzheimer s disease (AD) is linked with the appearance of symptoms in three key domains, namely activities of daily living (ADL), behaviour and cognition. The development and decline of these symptoms gives rise to a loss in the patient s functional capacity and contributes to the social, health care and economic costs associated with the disease. Tests suggest that the onset of these symptoms, in AD and in other types of dementia (e.g. frontotemporal dementia, dementia in Parkinson s disease and vascular dementia [VaD]), can be attributed to the loss of acetylcholine and cholinergic neurons in areas of the brain that are central to learning and memory, to execution functions and to behavioural and emotional responses, such as the cerebral cortex, the hippocampus and the limbic regions. There is evidence to show that the use of cholinesterase (ChE) inhibitors, including rivastigmine, donepezil and galanthamine, to enhance the survival of cholinergic neurotransmission is beneficial in the treatment of these symptoms. For example, administering rivastigmine stabilises and improves the performance of ADL in mild to moderate stages and slows down the decline in the capacity to carry out ADL in patients with serious AD. There is an improvement in the behavioural symptoms, the appearance of new symptoms diminishes and the use of other psychotropic drugs is reduced. Cognitive deficits become stable or improve during short term treatment and the treatment also delays the cognitive decline associated with the progression of the disease. A review of the available data reveals that ChE inhibition is beneficial in the long term in the three key symptomatic domains in different stages of the disease, as well as its perhaps being useful in different dementias. Therefore, it is likely that treatment with a ChE inhibitor improves quality of life and reduces the social and economic burden of these disorders

Acetylcholine↗
PubMed1976

The inhibition of DNA synthesis by cannabinoids.

Several of the cannabinoids found in marihuana have been shown to inhibit tumor growth and increase the life-span of mice bearing the Lewis lung adenocarcinoma. When trypsin-dispersed isolated Lewis lung cells are incubated in vitro, they maintain their capacity to carry out macromolecular synthesis (RNA, DNA, protein). This process can be inhibited by cytosine arabinoside, actinomycin D, or methyl-1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea, whereas cyclophosphamide, an agent that must be bioactivated, was inactive. Inhibition of DNA synthesis as measured by [3H]thymidine uptake into acid-insoluble material was used as an index of cannabinoid activity against isolated Lewis lung cells, L1210 leukemia cells, and bone marrow cells incubated in vitro delta9-, delta8-, 1-hydroxy-3-n pentyl-, and 1-delta8-tetrahydrocannabinol, and cannabinol demonstrated a dose-dependent inhibition of DNA synthesis whereas cannabidiol and 1-hydroxy-3-n-pentylcannabidiol were markedly less inhibitory in our in vitro cell systems. Furthermore, our in vitro observations with these cannabinoids are supported by in vivo tumor inhibition studies. Ring modifications as in cannabichromene or cannabicyclol abolish in vitro activity as does dihydroxylation at the 8beta and 11 positions of 1-delta9-trans-tetrahydrocannabinol. Delta9-trans-tetrahydrocannabinol demonstrated the least toxicity of all inhibitory cannabinoids in vivo; this is supported by its lesser effect on bone marrow DNA synthesis in vitro.

Animals↗
PubMed1992

Is the medical world ready for electronic journals?

New technologies offer new ways to deliver scholarly information, perhaps advantageously compared with paper journals, which have been an accustomed mode of scholarly communication for 300 years. Paper journals offer conveniences in handling and reading, and the economic constraints on their length tend to ensure that this constraint is important. Electronic journals are not yet as easy to use. But paper journals are economically cost effective and these space constraints prevent their publishing information not important to most readers but important to some. Electronic journals offer new advantages for readers, including the capacity to carry more and longer papers, linkages between related documents, and hypertext functions. The editors of The Online Journal of Current Clinical Trials welcome comments on its features and content; these should be sent to Dr. María L. Lebrón, Managing Editor, CCT, AAAS, 1333 H Street, NW, Washington, DC 20005 USA, FAX 202-842-2868.

Information Services↗
PubMedDate not supplied

Strengthening the public health system.

Although the American public health system has made major contributions to life expectancy for residents of this country over the past century, the system now faces more complex health problems that require comprehensive approaches and increased capacity, particularly in local and State public health agencies. To strengthen the public health system, concerted action is needed to meet these five critical needs: First, the knowledge base of public health workers needs to be supplemented through on-the-job training and continuing education programs. To this end, self-study courses will be expanded, and a network of regional training centers will be established throughout the country. Second, communities need dynamic leadership from public health officials and their agencies. To enhance leadership skills and expand the leadership role of public health agencies, focused personal leadership development activities, including a Public Health Leadership Institute, and national conferences will provide a vision of the future role of public health agencies. Third, local and State public health agencies need access to data on the current health status of the people in their communities and guidance from the nation's public health experts. To improve access to information resources, state-of-the-art technologies will be deployed to create integrated information and communication systems linking all components of the public health system. Fourth, local and State agencies need disease prevention and health promotion plans that target problems and develop strategies and the capacity to address them. To provide communities with structured approaches to this process, planning tools have been developed and distributed, and technical assistance will be provided to local and State health agencies to involve each community in planning,priority setting, and constituency building.Finally, public health agencies need adequate resources to fund prevention programs. To improve the use of existing Federal support and enhance the availability of new community resources, grant programs will be modified, and innovative approaches to local resource enhancement will be developed and shared.Activities in these five key areas are designed to improve the infrastructure of the public health system and its capacity to carry out effectively the core functions of public health assessment, policy development, and assurance of the availability of the benefits of public health. If the nation is to achieve the health objectives for the year 2000, the public health system-the individuals and institutions that, when working effectively together, promote and protect the health of the people-must be strengthened.

Computer Communication Networks↗
PubMedDate not supplied

[Perceptive and praxic impairments in traumatic brain injury patients: significance in activities of daily living].

OBJECTIVE: The main goal of the present study is to describe the implication of different perceptive and praxic deficits in activities of daily living (ADL). We also review some assessing scales and intervention techniques used in the training of these mentioned alterations after a traumatic brain injury (TBI). DEVELOPMENT: There are three kinds of processes important for a correct ideation, motor planification and execution of a learned purposeful movement (praxis). Some of these processes are related to the visual basic perception of the objects (colour, form, size, etc). Others are related to the most complex perception functions (depth, location, recognition,etc). The third group of functions are those integrating the sensory information (discrimination right left side, corporal scheme disorders, etc). If ADL performance needs a suitable functioning of different structures of the nervous central system, then assessment and treatment will be necessary to obtain the best independence level of TBI patients. This is the main objective in Occupational Therapy. ADL may be separated in two different groups: basic abilities (feeding, grooming, dressing, etc) and instrumental abilities (meal preparation, managing money, shopping, using public transportation, etc). CONCLUSION: Impairments in both praxic and perceptive processes constitute one of the most prevalent deficits in TBI patients. From a clinical point of view, these deficits may lack the capacity to carry an independent life.

Activities of Daily Living↗
PubMed2004

Urinary incontinence strategies for frail elderly women.

Among the majority of frail older women, urinary incontinence has not been adequately assessed or treated, with resultant negative impact on quality of life. An assessment and intervention model based on type of incontinence, evidence-based interventions, and the influence of patient preference and capacity to carry out interventions are described.

Activities of Daily Living↗