(n.) A resinous substance produced mainly on the banyan tree, but to some extent on other trees, by the Coccus lacca, a scale-shaped insect, the female of which fixes herself on the bark, and exudes from the margin of her body this resinous substance.
Example Sentences:
(1) Fifty-six percent of Lac+ transconjugants were resistant to the S. cremoris M12R lytic phage.
(2) We have previously shown that about 90% of total Escherichia coli lac repressor synthesized in mammalian cells is located in the cytoplasm [Hu and Davidson, Cell 48 (1987) 555-566].
(3) Hfr strains B4 and B8 transfer the Escherichia coli chromosome in opposite directions, each transferring lac(+) as the last known marker.
(4) Combined with histological analysis, these results suggest a more rapid recovery of normal spermatogenesis after physical insult with LAC treatment.
(5) The F'lac+ episome of Escherichia coli origin was transferred by conjugation with frequencies of 10(-7) to 10(-5) from Erwinia amylovora to 14 out of 15 Salmonella typhimurium trp female parents.
(6) A protein identical in properties to FIII L. casei lac was isolated from clones of E. coli carrying this DNA insert.
(7) Only one monoclonal antibody strongly inhibited cAMP binding by CRP, and this was accompanied by a consequent strong inhibition of both lac DNA binding and abortive initiation by RNA polymerase.
(8) These ends were cloned separately in lambdapMu hybrid particles that derived from a single Mu lysogen in the lac Z part of lambdaplac5.
(9) The structure of F13, a plasmid containing lac, purE, and proC, has been determined by heteroduplex analysis.
(10) In this case, resistance markers were lost when the transductants became Lac- but the derivatives remained copper resistant.
(11) Circular dichroic studies and hydropathy profiling of the amino-acid sequence of this 'lac' permease suggest a secondary structure in which the polypeptide consists of 12 hydrophobic segments in alpha-helical conformation that traverse the membrane in zig-zag fashion connected by shorter, hydrophilic domains with most of the charged residues and many of the residues commonly found in beta-turns.
(12) The strength of the STII gene promoter was compared with that of the ompF and lac operons, which were similarly fused to the lacZ gene.
(13) From the results of potassium iodide quenching of fluorescence from the tryptophans, and from attempts to react the native lac repressor with dimethyl(2-hydroxy-5-nitrobenzyl) sulfonium bromide and 2-hydroxy-5-nitrobenzyl bromide, we propose that tryptophan residue 209 is involved in a conformational change of the protein upon binding of inducer, but does not come in direct contact with inducer.
(14) In cells growing with interdivision times of 27, 36, and 55 min, the F'lac replicated at various stages in the division cycle but always at approximately the same time as initiation of chromosome replication.
(15) Expression of the blood group carbohydrates was similar in follicular and radicular cysts but differed from that seen in odontogenic keratocysts by the failure to detect N-lac in the latter.
(16) The phage lambda operator OR1 and a 18 base pair symmetric lac operator have been studied by high resolution NMR.
(17) Deletions covering all or part of the transfer region, as well as of lac and of pif, were obtained in the course of this analysis.
(18) A Mud(Ap, lac) prophage has been shown to be inserted into the ptsH gene of E. coli.
(19) From transient expression studies of the fusion gene between the chloramphenicol acetyltransferase and lac genes, it was found that the lacCAP binding site could act as an enhancer activity on the SV40 promoter, and also as an additive enhancer activity to the SV40 enhancer in HeLa cells.
(20) Expression of chlD-lac was increased in cells grown with nitrate.
Lack
Definition:
(n.) Blame; cause of blame; fault; crime; offense.
(n.) Deficiency; want; need; destitution; failure; as, a lack of sufficient food.
(v. t.) To blame; to find fault with.
(v. t.) To be without or destitute of; to want; to need.
(v. i.) To be wanting; often, impersonally, with of, meaning, to be less than, short, not quite, etc.
(v. i.) To be in want.
(interj.) Exclamation of regret or surprise.
Example Sentences:
(1) Here we have asked whether protection from blood-borne antigens afforded by the blood-brain barrier is related to the lack of MHC expression.
(2) tRNA from mutant IB13 lacks 5-methylaminomethyl-2-thio-uridine in vivo due to a permanently nonfunctional methyltransferase.
(3) BL6 mouse melanoma cells lack detectable H-2Kb and had low levels of expression of H-2Db Ag.
(4) Treatment termination due to lack of efficacy or combined insufficient therapeutic response and toxicity proved to be influenced by the initial disease activity and by the rank order of prescription.
(5) In the past, the interpretation of the medical findings was hampered by a lack of knowledge of normal anatomy and genital flora in the nonabused prepubertal child.
(6) A diplomatic source said the killing appeared particularly unusual because of Farooq lack of recent political activity: "He was lying low in the past two years.
(7) The present study examined whether the lack of chronic hemodynamic effects of ANP in control rats was due to changes in vascular reactivity to the peptide.
(8) Since it was established, it has stoked controversy about contemporary art, though in recent years it has been more notable for its lack of sensationalism.
(9) Inadequate treatment, caused by a lack of drugs and poorly trained medical attendants, is also a major problem.
(10) Because of the small number of patients reported in the world literature and lack of controlled studies, the treatment of small cell carcinoma of the larynx remains controversial; this retrospective analysis suggests that combination chemotherapy plus radiation offers the best chance for cure.
(11) I would immediately look askance at anyone who lacks the last and possesses the first.
(12) The detection of these antibodies is difficult owing to the lack of standardization and of specificity of the laboratory tests.
(13) Core enzyme, lacking omega subunit, catalyzed this reaction at a rate less than 1% that of holoenzyme.
(14) But not only did it post a larger loss than expected, Amazon also projected 7% to 18% revenue growth over the busiest shopping period of the year, a far cry from the 20%-plus pace that had convinced investors to overlook its persistent lack of profit in the past.
(15) Urine specimens from patient REE also contained a light chain fragment that lacked the first (amino-terminal) 85 residues of the native light chain but otherwise was identical in sequence to the light chain REE.
(16) Thus the failure to raise anti-Id with internal image characteristics may provide an explanation for the lack of anti-gp120 activity reported in anti-Id antisera raised to multiple anti-CD4 antibodies.
(17) His walkout reportedly meant his fellow foreign affairs select committee members could not vote since they lacked a quorum.
(18) In South Africa, health risks associated with exposure to toxic waste sites need to be viewed in the context of current community health concerns, competing causes of disease and ill-health, and the relative lack of knowledge about environmental contamination and associated health effects.
(19) The functional capacity to present antigens to T cells was lacking in normal resting B cells, but was acquired following LK treatment.
(20) These findings indicate an association between HLA-B7 and ankylosing spondylitis in American blacks and suggest that these patients who lack B27 but possess B7 represent a subgroup of patients with this disease.