SEARCH · Search PubMed

Results for “Resource”

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.

SourceResearch connectionFrom yearThrough year

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

At least 1,477 records · Page 82Linked to original sources

PubMed1997

Foraging currencies for non-energetic resources: pollen collection by bumblebees

Animals sometimes forage for resources whose benefits are not energy-based. In such cases, the benefits and costs of foraging cannot be directly compared, making it difficult to evaluate the currency of fitness maximized by the animal's behaviour. For bees, pollen represents such a resource, because they collect pollen as the sole protein source for developing larvae, rather than as a source of energy. This study compared three currencies that could be maximized during pollen collection by bumblebees (Bombus spp.) foraging on different lupin species (Lupinus spp.): pollen collected per inflorescence, pollen collection rate (gross benefits/time) and pollen collection efficiency (gross benefits/costs). Bees visiting lupin inflorescences begin foraging low on an inflorescence and then move upward through a gradient of increasing pollen availability. To maximize each currency, we predicted that a bee would begin foraging at a different position along a lupin inflorescence, depending on the relative influences of the time and energy costs associated with handling flowers and flight. Based on comparisons of observed and predicted starting positions for seven situations, maximization of gross pollen-collection efficiency predicted observed behaviour better than either pollen collected per inflorescence or gross rate of pollen collection. Such maximization of pollen-collection efficiency would enhance a bee's lifetime input of pollen to her colony, as has been demonstrated for nectar-collecting bees. Hence, the economics of foraging for non-energetic resources do not differ qualitatively from foraging for energy.Copyright 1997 The Association for the Study of Animal Behaviour1997The Association for the Study of Animal Behaviour

Journal Article↗

PubMed2000

Sentence repetition and processing resources in Alzheimer's disease.

Sentence processing in Alzheimer's disease (AD) has been found to be influenced by several grammatical and extragrammatical factors, including phrase structure and verb-argument relations, number of propositions/verbs, and processing resource capacity. This study examines the effects of these variables on sentence production in AD. Normal control and AD subjects were asked to repeat six types of sentences varying along the above dimensions of complexity. Subjects' processing resource capacity was measured using several verbal working memory tests. AD subjects' sentence-repetition performance was impaired compared to the normal control group. Significant effects were observed for branching direction of phrase structure, canonicity of verb-argument relations, and serial position of errors. Sentence-repetition performance significantly correlated with working memory scores. The findings are interpreted within a resource capacity theory of sentence processing.

Aged↗

PubMed1995

Competition for factors and cellular resources as a principle of pattern formation in Hydra. I. Increase of the potentials for head and bud formation and rescue of the regeneration-deficient mutant reg-16 by treatment with diacylglycerol and arachidonic acid.

The mutant strain reg-16 of Hydra magnipapillata has less capacity to regenerate a head than the wild-type strain 105 when examined in a standard test. The present comparative study with various strains of Hydra shows: (1) The head-forming potential of reg-16 and also of a widely used strain of Hydra vulgaris is severely impaired by the presence of a just-emerging or latent bud. (2) Periodic treatment with dioctanoylglycerol (DAG), a known activator of protein kinase C (PKC), plus arachidonic acid (AA), the mother compound of the eicosanoid signal substances, enabled reg-16 and H. vulgaris to insert additional tentacles into their original whorl while the export of cells by budding was reduced. (3) On the other hand, during the period of daily treatment with DAG+AA, potentials for head and bud formation were stored. Gastric segments excised from pretreated animals formed more tentacles than untreated wild-type 105 and even formed supernumerary head structures; in addition, segments excised from all body regions quickly resumed budding in spite of starvation and while they regenerated a head. (4) With continued treatment supernumerary tentacles were elicited in all strains although with high frequency only in Hydra magnipapillata, wt105. However, while wt105 formed supernumerary head structures preferentially at ectopic sites, reg-16, H. vulgaris, and Hydra oligactis instead increased the number of tentacles in the apical head, which occasionally split into two heads. (5) The treatment with DAG+AA caused the budding zone to shift closer to the foot end. (6) In H. vulgaris a pulse treatment with a high dose of DAG frequently caused a mirror image duplication of the budding zone; in wt105 mere excessive feeding over 2-3 weeks may have the same effect. The hypothesis is proposed that a regenerating head and a beginning bud compete for hormone-like factors, which enable the cells to increase positional value, and for precursor cells. Periodic treatment with activators of PKC plus AA leads to an augmentation of these resources, and head structures and buds can be produced simultaneously. Traditional terms are reinterpreted correspondingly: the high level of "head inhibition" in reg-16 is interpreted as a low level of resources, in particular, of head-promoting factors, and the low head activation level as a low ability to make use of resources.

Animals↗

PubMed1995

Competition for factors and cellular resources as a principle of pattern formation in Hydra. II. Assistance of foot formation by heads and buds and a new model of pattern control.

In Hydra long-range interactions between head, bud, and foot formation take place in addition to short-range interactions which are recognized as induction phenomena, occurring when transplants are placed into an environment of disparate positional value. Here the long-range promotion of foot formation is analyzed. The data show: (1) While head regeneration and the onset of budding are mutually inhibitory, in particular in Hydra vulgaris and strain reg-16 of Hydra magnipapillata, fully developed heads and advanced buds cooperatively support foot formation in both the bud and the parent. Utilizing these interdependences H. vulgaris can be caused to form ectopic feet and to regenerate feet at both ends of excised segments. (2) The foot-promoting activity returns late in head regeneration, as late as the apparent long-range "head inhibition" determined in transplantation studies. (3) While periodic treatment with diacylglycerol (DAG) increases the capacities to form heads and buds, the potency to form feet is transiently reduced. (4) When treatment with DAG is finished the elevated capacities to form heads and buds subside, in reg-16 and H. vulgaris there followed a phase of ectopic foot formation. (5) The foot does not promote head regeneration. Based on the results of this and previous studies the following hypotheses are proposed: (1) Heads and buds compete for resources, such as precursor cells and soluble head-promoting factors that are distributed in the interstitial spaces. (2) The ability to make use of these resources is associated with positional value and decreases down the body column. The decreasing capability is attributed to a decreasing complement of receptors for the head-promoting factors. (3) Feet are made by body regions which are the losers in the competition for these factors. (4) Superiority in the ability to compete for the locally available factors enables transplants to develop head structures, and inferiority causes them to form a foot. (5) Depletion of the head-promoting factors in the whole body column is a significant component of the "head inhibition potential" and mediates the assistance of heads and buds in foot formation. (6) A surplus of resources causes supernumerary head structures and delays or prevents foot regeneration. These interpretations have reference to a new receptor-based model of pattern control and are contrasted with prevailing hypotheses.

Animals↗

PubMed1993

Vertical integration of cosmid and YAC resources for interval mapping on the X-chromosome.

The vertical integration of cosmid and yeast artificial chromosome (YAC) resources is of particular importance in the development of high-resolution maps of selected regions of the human genome. A resource of approximately 95,000 cosmids constructed using DNA from primary fibroblasts of karyotype 49,XXXXX was validated by detailed characterization of a 200-kb cosmid contig spanning exons 8-20 of the dystrophin gene. This resource was used to construct contigs in 0.65 Mb of Xq26 by hybridization of gel-purified YAC DNA to high-density gridded arrays of the cosmid library; positive cosmids were overlapped by finger-printing. Contigs were oriented and ordered relative to existing YACs in the region using cross-hybridization. The overlaps between a representative set of cosmids define 54 intervals of 5-20 kb and were used to construct a high-resolution cosmid interval map of the region, locating markers, dinucleotide repeats, and candidate CpG islands. This approach can be applied rapidly to large regions of the genome and without recourse to subcloning of individual YACs.

Aneuploidy↗

PubMed1996

OncoLink: a cancer information resource for gynecologic oncologists and the public on the Internet.

The Internet is a computer network accessible to over 30 million computers users worldwide. By default, it has become the "information superhighway" that is growing at an explosive rate of between 1 and 2 million new users per month. Internet contains thousands of information of interest to cancer patients and healthcare professionals. Identifying the outstanding "golden" resources from the chaos is difficult. To address this problem and to provide information specific to gynecologic oncology, we developed a cancer information server called "OncoLink" at our institution that is available at no cost 24 hr per day, 7 days per week to all Internet users. OncoLink has two major goals: (1) To provide quality, original content for cancer patients and healthcare professionals and (2) to provide well-organized, consistent access to existing Internet cancer resources. This service may be used by anyone with a Microsoft Windows, Apple Macintosh, or UNIX computer. The service is rich in multimedia content containing text, pictures, illustrations, sound, and video. The information includes (1) original content written by authors at our institution, (2) original content submitted by authors from other institutions and, (3) publicly available information from other resources. Patient-oriented articles, physician-oriented review articles, and NIH, NCI, and FDA documents are available. All content is reviewed by an Editorial Board prior to posting. We have kept a detailed log file of each time the system has been accessed by an Internet user. OncoLink went online in March 1994. During the first 18 months (542 days) of operation, the service received 4,051,901 request for information from 105,589 unique Internet addresses worldwide. There is tremendous public and professional demand for online cancer information via the Internet. We feel that the Internet is an outstanding vehicle for providing quality cancer information for gynecologic oncologist other healthcare professionals, and the public.

Computer Communication Networks↗

PubMed1998

Process improvements reduce utilization of resources for aortic aneurysm repair.

In conjunction with the VA reorganization to promote greater efficiency of health care provision, ambulatory surgery (AS) programs have been created. These programs institute outpatient preoperative assessment and operative management. This study examines the impact of these process changes on resources utilized by patients requiring repair of abdominal aortic aneurysms (AAAs). The medical records of 15 consecutively treated patients undergoing elective, infrarenal AAA repair before (1992-1993) and after (1995-1996) AS implementation were reviewed. Resource utilization was assessed by evaluating preoperative tests performed (inpatient or outpatient), ICU days, and inpatient length of stay (LOS). Postoperative morbidity and mortality were noted. Patient age, AAA size, and prevalence of diabetes mellitus, hypertension, cardiac disease, COPD, and tobacco use were similar between the two groups. Abdominal ultrasound, CT scanning, and angiography were significantly more frequently performed on an outpatient basis after implementation of the AS program. The median preoperative LOS was reduced in the AS group (1 vs 6 days, P = 0.001, Student t test), resulting in a lower inpatient LOS (11 vs 16, P < 0.01, Student t test). All patients survived and the incidence of complications was similar between the groups. Hospital resource utilization was significantly decreased, largely by shifting preoperative assessment to the outpatient setting. This study illustrates that benefits of an ambulatory surgery program can be extended beyond facilitating outpatient operations and should result in decreased length of hospitalization for other major surgical procedures, such as abdominal aortic aneurysm repair.

Aged↗

PubMed1999

Patterns of morbidity and resource consumption associated with laparoscopic cholecystectomy in a VA medical center.

BACKGROUND: The generally low incidence of morbidity and reduced rate of health care resource consumption commonly associated with laparoscopic cholecystectomy (LC) have been established from studies of patient populations which are distinct from that served by the Department of Veterans Affairs (VA) health care system. We sought to assess the outcomes of this procedure when performed on VA beneficiaries. MATERIALS AND METHODS: Demographic and perioperative data for all patients undergoing attempted LC in our facility were recorded in a prospective database beginning 1 January 1993. The information in this registry was analyzed to determine the demographics of the treated population, the spectrum of biliary tract disease encountered, and patterns of morbidity and resource consumption. RESULTS: LC was attempted in 141 cases. Median patient age was 62 years. The indication for surgery was either acute cholecystitis or biliary pancreatitis in 63 cases (45%). Thirteen patients (9%) developed major complications. These patients were significantly older (mean age 68 vs 59 years) than patients whose course was uncomplicated. Twenty-seven cases (19%) required conversion to an open procedure, most commonly for acute cholecystitis. Progressive cholecystitis was associated with a conversion rate of 64%. Both conversion and the development of a major complication produced significant increases in length of stay. CONCLUSIONS: The population undergoing attempted LC in the VA system is characterized by relatively advanced age and high incidences of comorbid illness and complicated biliary tract disease. These attributes increase the frequency of major morbidity and of conversion to open cholecystectomy, which in turn increase resource consumption. Comparisons between the outcomes of attempted LC in VA centers and "benchmark" results obtained in other settings should be controlled for these factors.

Acute Disease↗

PubMed2001

Effects of habitat destruction and resource supplementation in a predator-prey metapopulation model.

We developed a mean field, metapopulation model to study the consequences of habitat destruction on a predator-prey interaction. The model complements and extends earlier work published by Bascompte and Solé (1998, J. theor. Biol.195, 383-393) in that it also permits use of alternative prey (i.e., resource supplementation) by predators. The current model is stable whenever coexistence occurs, whereas the earlier model is not stable over the entire domain of coexistence. More importantly, the current model permits an assessment of the effect of a generalist predator on the trophic interaction. Habitat destruction negatively affects the equilibrium fraction of patches occupied by predators, but the effect is most pronounced for specialists. The effect of habitat destruction on prey coexisting with predators is dependent on the ratio of extinction risk due to predation and prey colonization rate. When this ratio is less than unity, equilibrial prey occupancy of patches declines as habitat destruction increases. When the ratio exceeds one, equilibrial prey occupancy increases even as habitat destruction increases; i.e., prey "escape" from predation is facilitated by habitat loss. Resource supplementation reduces the threshold colonization rate of predators necessary for their regional persistence, and the benefit derived from resource supplementation increases in a nonlinear fashion as habitat destruction increases. We also compared the analytical results to those from a stochastic, spatially explicit simulation model. The simulation model was a discrete time analog of our analytical model, with one exception. Colonization was restricted locally in the simulation, whereas colonization was a global process in the analytical model. After correcting for differences between nominal and effective colonization rates, most of the main conclusions of the two types of models were similar. Some important differences did emerge, however, and we discuss these in relation to the need to develop fully spatially explicit analytical models. Finally, we comment on the implications of our results for community structure and for the conservation of prey species interacting with generalist predators.

Animals↗

PubMed1988

The context of clinical judgment: the effect of resource availability on judgments of amenability to treatment in juvenile offenders.

One-hundred sixty-eight mental health, welfare, and juvenile court personnel from six different locales within a state rated (a) the "amenability to treatment" of four case vignettes involving juvenile offenders and (b) the effectiveness of a variety of services for youth. Locales were chosen as either low, medium, or high along a continuum of service availability, and the effects of resource availability and agency type on these judgments were examined. These factors had significant effects on both types of judgments, but the directions of the effects were not uniform. Personnel in both high and low resource conditions showed relatively lower ratings of amenability on the vignettes and significant positive correlations between the ratings of service effectiveness and the treatability of the vignette youth. The medium resource personnel in all three agencies showed a negative correlation between these ratings, thus portraying youth as more workable but services as not maximally effective. In general, the results are interpreted as evidence that clinical judgment is systematically affected more by contextual factors than assumed and that this fact bears consideration in formulating the proper role for clinical judgment in juvenile justice.

Adolescent↗

PubMed1985

Chronic medical problems, coping resources, and depression: a longitudinal study of rural Tennesseans.

This analysis examined chronic medical problems as a risk factor for depressive symptomatology using longitudinal survey data from a sample of rural Tennesseans. Two waves of data (1977 and 1983) were collected on 532 rural Middle-Tennessee residents. An initial investigation found chronic medical problems a powerful predictor of depression. Furthermore, internal and external resources (personal resources and social support) operated as moderating factors between the stress of medical problems and psychiatric impairment. Panel regression analyses indicated that Time 1 depression level as well as medical problems at Time 2 (t2) were significant predictors of depression at t2 in rural areas of the mid-South. Finally, the buffering effects of both social support and personal resources were explored.

Adaptation, Psychological↗

PubMed1996

Conservation of Living Resources in a Changing World

/ Conservation of living resources is no longer parochial in scope; it is a global challenge. Ecological, social, political, and business interests operate in a network that reaches across seas, continents, and nations. Industries, including the electric utility industry, are diversifying in products and expanding into international markets. They soon discover that, while all nations have common goals for their peoples, conservation and environmental issues in less-developed nations have different dimensions and norms than are encountered in Western, affluent societies. In developing countries, survival is more of an issue than quality of life, and burgeoning human numbers have put tremendous pressures on resources including wildlife and its habitats. Human population, urbanization of society, changes in single-species to ecosystem and landscape levels of management, and protectionists and animal rights philosophies are influences with which conservation of resources and the environment must contend. The human condition and conservation efforts are inextricably linked. Examples to demonstrate this fact are given for Project Tiger in India, the jaguar in Latin America, and the Serengeti ecosystem in Kenya and Tanzania.KEY WORDS: Conservation; Global, Developed nations; Developing nations; Wildlife; Habitat

Journal Article↗

PubMed1993

Rural hospital health promotion: programs, methods, resource limitations.

Most hospitals provide health promotion programs for community residents. There is little information concerning the specific types of services offered by rural hospitals. A questionnaire was sent to every acute care hospital in Iowa (N = 124), including 99 rural hospitals and 25 urban hospitals. Surveys were returned from 95 rural hospitals (96%) and 20 urban hospitals (80%). Results indicated that 98.9% of rural hospitals offered health promotion services to community residents. These services provided on average 7.5 programs on a regular basis, while using only 1.2 full-time equivalent (FTE) employees. Urban hospitals provided 9.5 regular programs with 2.4 FTE. The most common types of rural promotion programs were blood pressure screening, cholesterol screening, safety and protection programs, diet/nutrition programs, prenatal/maternal health, and breast cancer screening. Over 40% of rural respondents stated that other less common programs, including substance abuse prevention and mental health promotion, were needed but could not be offered because of resource limitations; these types of services were offered more commonly in urban hospitals. Rural hospital health promotion programs are attempting to meet a wide variety of programming needs with limited resources, and attention may be well directed towards finding how best to provide various programs with limited resources to maximize their impact on community health.

Community Health Services↗

PubMed2001

Does managed mental health care reallocate resources to those with greater need for services?

Evidence points to the existence of two coexisting inefficiencies in mental health care resource allocation: those with need receive too limited or no care while those with no apparent need receive services. In addition to reducing costs, managed mental health care is expected to reallocate treatment resources to those with greater need for services. However, there are no empirical findings regarding this issue. This study tests whether managed mental health care has had a differential impact by level of need. Data consist of three waves of a community sample with a control group. The study finds that managed care has not succeeded in reallocating resources from the unlikely to the definite "needers."

Adolescent↗

PubMed1996

Stress, coping, HIV status, psychosocial resources, and depressive mood in African American gay, bisexual, and heterosexual men.

The associations between stress, physical health, psychosocial resources, coping, and depressive mood were examined in a community sample of African American gay, bisexual, and heterosexual men (N = 139). Data were collected from physical exams and in-person interviews. In our theoretical framework, depressive mood scores were regressed first on stressors, next on psychosocial resources, and finally on coping strategy variables. Results revealed that psychosocial resources mediate the effects of stressors, including health symptoms, hassles, and life events, on depressive mood. There were no significant differences in depressive mood associated with HIV status or sexual orientation. Results are discussed in terms of community interventions needed to provide social support as a buffer between stress and psychological distress in African American men.

Adaptation, Psychological↗

PubMed2003

Agrobiodiversity with emphasis on plant genetic resources.

The science of agrobiodiversity has emerged during the last 10 years. We review here the most important aspects of biodiversity for conservation. One of the aims of agrobiodiversity research is to introduce or to re-introduce into present-day agriculture and horticulture more diversity from gene banks, botanical or zoological gardens, and other secondary sources of diversity. To enlarge the basis of agricultural and horticultural resources for human and animal nutrition, a sustainable use of these native and cultivated resources is necessary, including animal and plant genetic resources. The total number of botanical plant species cultivated as agricultural or horticultural crops is estimated at almost 7,000. However, only 30 major crop species "feed the world". Comparable numbers of animal species have been lost. The reduction in crop species and variety diversity, in particular, has led to the establishment of germplasm collections, so called gene banks, or ex situ collections. Six million plant accessions are conserved in gene banks worldwide. All these accessions belong to a very limited number of species. About half of them are advanced cultivars or breeders' lines, and only a third are landraces or old cultivars. Approximately 15% are wild relatives of crop species and weeds. Among other obvious gaps, minor crops and underutilized species are underrepresented in these collections, particularly primitive cultivars and wild relatives from the centers of origin, diversity, and cultivation. To date, only a third of all gene bank accessions have been fully characterized.

Agriculture↗

PubMed2025

Genomics-enabled dissection of sea wheatgrass genome for advancing wheat genetic resources.

Wheat production is challenged by biotic and abiotic stresses. Alien gene transfer is an effective approach to tackle such challenges. We previously showed that sea wheatgrass (SWG; Thinopyrum junceiforme (2n = 2x = 28; J1J2) is an untapped resource possessing resistance to an array of pests and abiotic stress. However, the transfer of these important traits has been hindered by the lack of genomic resources and a clear picture of its genome constitution. Using multi-color genomic in situ hybridization, we distinguished the SWG sub-genomes and corroborated that the J1 sub-genome is closely related to the E genome of Th. elongatum and the J genome of Th. bessarabicum and the J2 sub-genome to the V genome of Dasypyrum villosum. Meanwhile, we developed a draft SWG genome assembly and 127 SWG-specific DNA markers covering the 14 SWG chromosomes. Screening a population of 466 BC2F1 and BC2F2 individuals, derived from backcrosses of wheat-SWG amphiploid to wheat, by the SWG-specific markers led to selection of 72 plants putatively carrying one or two SWG chromosomes. The genome painting analysis of the 72 plants eventually identified a set of 37 wheat-SWG chromosome addition lines covering all the 14 pairs of SWG chromosomes and two compensating Robertsonian translocations (RobTs). While the wheat-SWG chromosome addition lines and RobTs are invaluable genetic resources for wheat improvement via chromosome engineering, our results showed the power of genome-specific markers in combination with genome painting in dissection of a polyploid genome and implicated the origin of a group of important polyploid grasses.

Triticum↗

PubMed2025

Genomic prediction-aided incorporation of genetic resources into elite breeding: lessons from a collaborative multiparental design in flint maize.

A public private cooperative mating design between elite maize inbred lines and diversity donors shows that genomic prediction holds great promise to improve the use of genetic resources. Genetic diversity is essential for plant breeding, enabling long-term gains and adaptation to climate change and new agronomical practices. Breeders can access diverse genetic resources to enhance elite germplasm and introduce new favorable variations. The limited performance of genetic resources may hamper their use. To overcome this, a bridging population can be implemented to evaluate and select progenies from crosses between diversity donors and elite lines before their introduction in breeding programs. The choice of such crosses can be dealt with the usefulness criterion (UC), which determines its ability to produce transgressive individuals. This paper investigates the use of genome-wide marker effects to predict (i) the performance of individuals derived from crosses between donors and elite lines and (ii) the UC of crosses not observed yet. It also compares donor introduction strategies based on the UC or the H criterion, which considers the genome-wide donor-elite complementarity. We used a flint maize collaborative multi-parental BC1-S2 population, consisting in materials from six breeding companies and one public institute crossed to different donors. The 20 crosses had contrasted means and genetic variances, and most of them presented transgressive individuals above the elite parent. Results emphasize the importance of half-siblings derived from the elite line parent of the predicted cross to efficiently predict progeny performances or the UC. They also showed that using the H criterion appears promising to select iteratively donors that best complement initial elite materials. The paper concludes with guidelines for implementing a bridging population using genome-wide marker-based predictions.

Zea mays↗