Global stability in a chemostat with multiple nutrients

We study a single species in a chemostat, limited by two nutrients, and separate nutrient uptake from growth. For a broad class of uptake and growth functions it is proved that a nontrivial equilibrium may exist. Moreover, if it exists it is unique and globally stable, generalizing a result in [15]. supported in part by NSF grant DMS 0342153. supported in part by NSF grant DEB-0083566 and the Andrew W. Mellon Foundation. supported in part by USAF grant F49620-01-1-0063 and NSF grant CCR-0206789. Part of this work was carried out when P. De Leenheer was a post-doctoral fellow at DIMACS, Rutgers University, supported in part by NSF grant EIA03-331486 and USAF grant F49620-01-1-0063.     

Interval graphs and maps of DNA

A special class of interval graphs is defined and characterized, and an algorithm is given for their construction. These graphs are motivated by an important representation of DNA called restriction maps by molecular biologists. Circular restriction maps are easily included. Supported by a grant from the System Development Foundation. Supported by an NSF grant and through a grant from the System Development Foundation.     

Pattern recognition in several sequences: Consensus and alignment

The comparison of several sequences is central to many problems of molecular biology. Finding consensus patterns that define genetic control regions or that determine structural or functional themes are examples of these problems. Previously proposed methods, such as dynamic programming, are not adequate for solving problems of realistic size. This paper gives a new and practical solution for finding unknown patterns that occur imperfectly above a preset frequency. Algorithms for finding the patterns are given as well as estimates of statistical significance. This author supported by a grant from the System Development Foundation. This author supported by NSF grant MCS-8301960 and by a grant from the System Development Foundation. This author supported by NIH grant GM19036.     

Did the first Global Fund grant (2003-2006) contribute to malaria control and health system strengthening in Timor-Leste?

ABSTRACT: BACKGROUND: In 2003, Timor-Leste successfully obtained its first Global Fund grant for a three-year programme for malaria control. The grant aimed to reduce malaria-related morbidity and mortality by 30 % by the end of the implementation. METHODS: A mixed-methods approach was used to assess the impact of the grant implementation. Fiftyeight in-depth interviews, eight group interviews, 16 focus group discussions, and on-site observations were used. Morbidity data reported to the Ministry of Health were also examined to assess trends. RESULTS: The National Malaria Programme with funding support from the Global Fund grant and other development partners contributed considerably to strengthening malaria control and the general health system. It also brought direct and indirect benefits to pregnant women and to the community at large. However, it failed to achieve the stated objective of reducing malaria morbidity and mortality by 30 %. The implementation was hampered by inadequate human resources, the rigidity of Global Fund rules, weak project management and coordination, and inadequate support from external stakeholders. CONCLUSION: Despite limitations, the grant was implemented until the agreed closing date. Considerable contributions to malaria control, health system, and the community have been made and the malaria programme was sustained.     

Tutorial on large deviations for the binomial distribution

We present, in an easy to use form, the large deviation theory of the binomial distribution: how to approximate the probability ofk or more successes inn independent trials, each with success probabilityp, when the specified fraction of successes,a≡k/n, satisfies 0<p<a<1. Supported by NIH grant GM 36230 and NSF grant DMS 8601986. Supported by NIH grant GM 36230 and a grant from the System Development Foundation.     

The grant is what I eat: the politics of social security and disability in the post-apartheid South African state

In South Africa, disability grant allocation has been under review and tensions are evident in government rhetoric stressing welfare provision on the one hand, and encouraging 'rationalization' on the other. This ambiguity is traced down to the level of grant negotiations between doctors and 'clients' in a psychiatry clinic in Khayelitsha. Here 'having nerves' embodies the distress associated with harsh circumstances and is deemed by supplicants as sufficient to secure a grant. The paper illustrates how national discourses influence the presentation and experience of suffering and the way in which doctors mediate diagnoses. The implications of local understandings of 'health citizenship' for expectations of the post-apartheid state are explored.     

Autoactive molluscan neuron: Reflex function and synaptic modulation during feeding in the terrestrial slug,Limax maximus

Summary The salivary burster (SB) is an autoactive motoneuron to the salivary duct of the terrestrial slugLimax maximus. The SB is electrically coupled to protractor motoneurons and inhibited by the metacerebral giant cell. During feeding these synaptic inputs cause SB activity to be phase-locked to the protraction-retraction cycle. The SB can be used as a clear and reliable monitor of feeding motorprogram activation.We thank Dr. Joseph Jin Chang for invaluable assistance with some of this work. Support was provided by NSF grant BMS74-15217 to D.J.P., NSF grant BMS74-03572 to A.G., and a grant from the Spencer Foundation.     

The trade-off between mutual interference and time lags in predator-prey systems

We present a Gause predator-prey model incorporating mutual interference among predators, a density-dependent predator death rate and a time lag due to gestation. It is well known that mutual interference is stabilizing, whereas time delays are destabilizing. We show that in combining the two, a long time-lag usually, but not always, destabilizes the system. We also show that increasing delays can cause a bifurcation into periodic solutions. Research for this paper was partly supported by the Natural Science and Engineering Council of Canada, grant No. NSERC A4823, and by a grant from the University Grants Commission, New Delhi, India, grant No. F. 23-1174/79 (S.R. II).     

Peer Review of Grant Applications: Criteria Used and Qualitative Study of Reviewer Practices

Background

Peer review of grant applications has been criticized as lacking reliability. Studies showing poor agreement among reviewers supported this possibility but usually focused on reviewers’ scores and failed to investigate reasons for disagreement. Here, our goal was to determine how reviewers rate applications, by investigating reviewer practices and grant assessment criteria.

Methods and Findings

We first collected and analyzed a convenience sample of French and international calls for proposals and assessment guidelines, from which we created an overall typology of assessment criteria comprising nine domains relevance to the call for proposals, usefulness, originality, innovativeness, methodology, feasibility, funding, ethical aspects, and writing of the grant application. We then performed a qualitative study of reviewer practices, particularly regarding the use of assessment criteria, among reviewers of the French Academic Hospital Research Grant Agencies (Programmes Hospitaliers de Recherche Clinique, PHRCs). Semi-structured interviews and observation sessions were conducted. Both the time spent assessing each grant application and the assessment methods varied across reviewers. The assessment criteria recommended by the PHRCs were listed by all reviewers as frequently evaluated and useful. However, use of the PHRC criteria was subjective and varied across reviewers. Some reviewers gave the same weight to each assessment criterion, whereas others considered originality to be the most important criterion (12/34), followed by methodology (10/34) and feasibility (4/34). Conceivably, this variability might adversely affect the reliability of the review process, and studies evaluating this hypothesis would be of interest.

Conclusions

Variability across reviewers may result in mistrust among grant applicants about the review process. Consequently, ensuring transparency is of the utmost importance. Consistency in the review process could also be improved by providing common definitions for each assessment criterion and uniform requirements for grant application submissions. Further research is needed to assess the feasibility and acceptability of these measures.     

Lymphatic endothelium in health and disease

The lymphatic vascular system has an important role in the maintenance of tissue fluid pressure homeostasis, in the mediation of the afferent immune response via recruitment of antigen-presenting cells toward draining lymph nodes, and in the intestinal absorption of dietary lipids. Substantial progress in our understanding of the development and the molecular mechanisms controlling the lymphatic system has been made during the last few years, based on a recent wave of discoveries of lymphatic endothelial cell-specific markers and growth factors. This has also led to new insights into the role of lymphatic endothelium in a number of diseases, including primary and secondary lymphedemas. The emerging role of lymphatic endothelium in the context of inflammation indicates that therapeutics targeting the lymphatic vasculature might represent a new strategy for anti-inflammatory therapies. Research from the authors' laboratory is supported by National Institutes of Health grant CA69184, Swiss National Fund grant 3100A0-108207, Austrian Science Foundation grant S9408-B11, Cancer League Zurich, and Commission of the European Communities grant LSHC-CT-2005-518178 (M.D.).     

Granule formation in animal tissues byCandida albicans

Summary 1. Granule formation byCandida albicans in the internal organs of experimental animals is described. This appears to be the first time such an observation has been made.2. Ring formation by fungi under different conditions is cited, and although different explanations have been proposed by different authors, the supposition is made that a common growth pattern is involved.Supported in part by a grant from the Eli Lilly Company and partly by an institutional grant from the American Cancer Society.     

Quantitative autoradiographic assessment of 3H-estradiol uptake in immunocytochemically characterized pituitary cells

Summary Dry-mount autoradiography was combined with peroxidase immunocytochemistry to examine estrogen uptake in four pituitary cell types. Quantification by silver grain counts was used to compare ³H-estradiol uptake in nuclei of pituitary cells 60 min after i.v. injection into short-term (control) and long-term ovariectomized and in long-term thyroidectomized rats. Under all three hormonal states, the order of labeling intensity was: gonadotropes > somatotropes > lactotropes > thyrotropes. Long-term ovariectomy caused a significant increase in estrogen uptake of gonadotropes, somatotropes and lactotropes, while uptake in thyrotropes decreased. Long-term thyroidectomy decreased uptake in somatotropes, lactotropes and thyrotropes while gonadotropes remained unchanged.Supported by NICHHD grant HD-03007 to D.A.K., NICHHD grant HD-03110 to the Biological Sciences Research Center of Child Development Research Institute and a grant from the Rockefeller Foundation to the Laboratories for Reproductive Biology.     

A simple EMG—Reward system for biofeedback training of children

An automated reward system to be used with standard electromyographic (EMG) biofeedback instrumentation is described. The on-line reward system, when coupled with standard biofeedback instrumentation and procedures, constitutes instrumental conditioning. In addition to describing the EMG—reward interface circuity, a study demonstrating the efficacy of the instrumental conditioning approach with cerebral-palsied children is presented.This research was aided by a grant from the Easter Seal Research Foundation of the National Easter Seal Society for Crippled Children and Adults, and by a grant from the Tulsa Cerebral Palsy Association.     

Storage of Doppler-shift information in the echolocation system of the “CF-FM”-bat,Rhinolophus ferrumequinum

Summary The greater horseshoe bat (Rhinolophus ferrumequinum) emits echolocation sounds consisting of a long constant-frequency (CF) component preceeded and followed by a short frequency-modulated (FM) component. When an echo returns with an upward Doppler-shift, the bat compensates for the frequency-shift by lowering the emitted frequency in the subsequent orientation sounds and stabilizes the echo image. The bat can accurately store frequency-shift information during silent periods of at least several minutes. The stored frequency-shift information is not affected by tone bursts delivered during silent periods without an overlap with an emitted orientation sound. The system for storage of Doppler-shift information has properties similar to a sample and hold circuit with sampling at vocalization time and with a rather flat slewing rate for the stored frequency information.Supported by Stiftung Volkswagenwerk, grant No. 111858, Deutsche Forschungsgemeinschaft, grant No. Ne 146/7, National Science Foundation (USA), grant No. GB-40018 and the Alexander von Humboldt-Stiftung.     

Batrachotoxinin-A 20-α-benzoate: A new radioactive ligand for voltage sensitive sodium channels

Batrachotoxinin-A 20--benzoate (BTX-B), an analog of the potent depolarizing agent batrachotoxin (BTX), was prepared by selective esterification of naturally occurring batrachotoxinin-A with benzoic acid. BTX-B depolarizes rat phrenic nerve-diaphragm preparations with a time course and concentration dependence virtually indistinguishable from that of BTX. A specific, saturable component of equilibrium binding of [³H]BTX-B to mouse cerebral cortex homogenates was measured, described by an equilibrium dissociation constant of 0.7 µM and a maximum number of binding sites of 90 pmol per gram of tissue (wet weight). Specific binding is inhibited by BTX and other BTX analogs, veratridine, and grayanotoxin but is unaffected by tetrodotoxin and cevine. Under conditions of this assay, neither crude Leiurus quinquestriatus scorpion venom nor purified sea anemone toxin have any effect on specific binding. The data support the conclusion that BTX-B interacts with a recognition site associated with voltage sensitive sodium channels which is identical to the recognition site for BTX.This work was supported by a grant from the Alabama Affiliate of the American Heart Association and a NIH grant NS 15617 to G.B.B. and by USPHS grant NS-12063 and Army research office grant 29-78-G-0203 to E.X.A.     

Membrane function in cystic fibrosis. I. Putrescine transport in normal and cystic fibrosis fibroblasts

Putrescine transport was examined in normal and cystic fibrosis fibroblasts. No differences were observed in accumulation pattern, kinetics of uptake, or efflux between CF and normal cells. In both growing and growth-arrested CF and normal fibroblasts, exogenously supplied putrescine remained unchanged for at least 60 min. Some differences were observed in the response of CF and normal cells to environmental (media) changes.This research was supported by a grant from the Cystic Fibrosis Foundation and by a grant from the National Institutes of Health, Training Grant (GM01316 11 GNC).     

Hypertension self-control with a portable feedback unit or meditation-relaxation

Thirty borderline essential hypertensives were randomly assigned to a portable constant-cuff blood pressure feedback technique or meditation-relaxation. Each technique was taught in the laboratory, then practiced twice daily at home for four weeks. Subjects mailed daily records of their progress. Seven feedback and ten meditation-relaxation subjects completed the program. Both techniques produced significant systolic and diastolic reductions within practice sessions and diastolic reductions over weeks of training. Neither technique improved reductions nor reduced initial systolic pressure levels over the four weeks. Differences between biofeedback and meditation-relaxation in within-session pressure reductions were not significant.This study was supported by NIMH grant MH27214 to Joanne L. Hager, NIMH grant MH8880-2 to Elliot Mishler, and NIMH grant MH25104 to Richard S. Surwit. The authors are grateful to the Parke-Davis Instrument Co. who provided the instrumentation for this study.     

Alfalfa saponins as inhibitors of cotton seed germination

The inhibitory effect of alfalfa saponins on the germinationof cotton seeds was primarily attributed to interference withthe seedcoat and with the membrane. This effect was not dueto impermeability to water. ¹This work was supported in part by grant No. FG-Is-246 fromthe U.S. Department of Agriculture, and a grant from the Committeefor the Encouragement of Research, General Federation of Labour,in Israel (Received December 8, 1969; )     

Calcium-controlled peroxidase secretion by sugarbeet cell suspensions in relation to habituation

Sugarbeet cells from normal and habituated callus released peroxidases in liquid cultures, in proportion to their endogenous level. Calcium promoted this release more in the normal than in the habituated line. Treatment of the cells with sodium azide, sodium hydrogenarsenate or phenothiazine inhibited the calcium effect, which indicated a dependence on metabolic energy and on calmodulin regulation. The Ca ionophore Ro (bromolasalocid ethanolate) restricted peroxidase release.Research partly supported by the Belgian FRFC grant 2.9009 to T.G. and by the Swiss FNSR grant 3.624-0.80 to C.P. and H.G.     

Genetic mapping of aminoglycoside and fusidic acid resistant mutations in Bacillus subtilis

Summary Mutations governing resistance to neamine, neomycin, kanamycin and fusidic acid have been mapped within the ribosomal region of theBacillus subtilis genome using PBS1-mediated transduction. The probable order of these closely linked markers is: This work was supported by a predoctoral training grant, GM-1290, from the National Institutes of Health, administered by the Department of Microbiology, N.Y.U. School of Medicine, and by a research grant from the National Science Foundation, GB-16782, awarded to I.S.