Coding for computing Orlitsky, A.; Roche, J.R.
IEEE transactions on information theory,
03/2001, Letnik:
47, Številka:
3
Journal Article
Recenzirano
A sender communicates with a receiver who wishes to reliably evaluate a function of their combined data. We show that if only the sender can transmit, the number of bits required is a conditional ...entropy of a naturally defined graph. We also determine the number of bits needed when the communicators exchange two messages.
A compilation of data on the elemental composition of marine phytoplankton from published studies was used to determine the range of Cratio Nratio P. The Nratio P ratio of algae and cyanobacteria is ...very plastic in nutrient-limited cells, ranging from <5 mol Nratio mol P when phosphate is available greatly in excess of nitrate or ammonium to >100 mol Nratio mol P when inorganic N is present greatly in excess of P. Under optimal nutrient-replete growth conditions, the cellular Nratio P ratio is somewhat more constrained, ranging from 5 to 19 mol Nratio mol P, with most observations below the Redfield ratio of 16. Limited data indicate that the critical Nratio P that marks the transition between N- and P-limitation of phytoplankton growth lies in the range 20–50 mol Nratio mol P, considerably in excess of the Redfield ratio. Biochemical composition can be used to constrain the critical Nratio P. Although the biochemical data do not preclude the critical Nratio P from being as high as 50, the typical biochemical composition of nutrient-replete algae and cyanobacteria suggests that the critical Nratio P is more likely to lie in the range between 15 and 30. Despite the observation that the overall average Nratio P composition of marine particulate matter closely approximates the Redfield ratio of 16, there are significant local variations with a range from 5 to 34. Consistent with the culture studies, lowest values of Nratio P are associated with nitrate- and phosphate-replete conditions. The highest values of Nratio P are observed in oligotrophic waters and are within the range of critical Nratio P observed in cultures, but are not so high as to necessarily invoke P-limitation. The Cratio N ratio is also plastic. The average Cratio N ratios of nutrient-replete phytoplankton cultures, oceanic particulate matter and inorganic N and C draw-down are slightly greater than the Redfield ratio of 6·6. Neither the analysis of laboratory Cratio Nratio P data nor a more theoretical approach based on the relative abundance of the major biochemical molecules in the phytoplankton can support the contention that the Redfield Nratio P reflects a physiological or biochemical constraint on the elemental composition of primary production.
Incidence of invasive meningococcal disease has increased recently in persons aged 15 through 24 years.
To characterize meningococcal infection in adolescents and young adults in Maryland during the ...1990s.
Population-based surveillance study for meningococcal disease from January 1, 1990, through December 31, 1999, in Maryland.
Maryland residents diagnosed as having invasive meningococcal disease.
Invasive meningococcal infection.
Of 295 total cases, 71 (24.1%) occurred among persons aged 15 through 24 years. Sixteen (22.5%) of these cases were fatal. The annual incidence rate increased from 0.9 to 2.1 cases per 100 000 among 15 through 24 year olds (P =.01). The proportion of all disease increased from 16.0% to 28.9% (P =.03). The incidence and proportion of cases subsequently decreased to 1.0 and 16.4% in 1998 through 1999, respectively. Infection in 15 through 24 year olds was more likely to be fatal than infection in those younger than age 15 years (22.5% vs 4.6%; P =.001). Infection in 15 through 24 year olds, compared with those aged 25 years or older, was more likely to be associated with male sex (66.2% vs 34.8%; P<.001) and serogroup C infection (46.9% vs 20.2%; P<.001), respectively. Infections were potentially preventable with the licensed meningococcal vaccine in 82.8% of 15 through 24 year olds, 68.1% of those younger than 15 years, and 76.8% of adults aged 25 years or older.
Incidence of meningococcal infection in 15 through 24 year olds in Maryland increased and then declined during the 1990s. Infection in this age group was associated with an unusually high case-fatality ratio, and the vast majority of cases were potentially vaccine preventable.
The ingestion of scarlet pimpernel (Lysimachia arvensis L.), also known as red chickweed, has been reported as a cause of death of cattle in Uruguay, and as the suspected cause of deaths of sheep in ...Australia. It has not previously been reported in association with deaths of cattle in Australia. We report the clinical and pathological findings from four cattle in western Victoria that died with a nephrosis suspected to be secondary to intoxication with scarlet pimpernel.
An investigation of the palladium-catalyzed Kumada cross-coupling reaction between PhMgBr and (pseudo-ortho) 4,12-diiodo-1,1,2,2,9,9,10,10-octafluoro2.2paracyclophane revealed that in addition to ...the expected cross-coupled product, an unintended major product was generated. The product was determined to be 9,9,10,10-tetrafluoro-1,2,4,12-tetraphenyl2.2paracyclophan-1-ene by X-ray crystallography and is proposed to be formed via the first reported example of reductive defluorination by a Grignard reagent.
This paper reports an investigation into metabolic and endocrine maturity in the neonate lamb and the relationships between litter size, birth weight, and maternal metabolic and endocrine variables ...on behavior at birth and survival over the first 72 h of life. Data were from multiparous, fine-wool Merino ewes (n = 150; equal numbers of single-lamb and twin-lamb bearing status) lambed on pasture after late gestational glucocorticoid treatments. Stepwise multiple regression analysis was used to investigate relationships between lamb survival, behavior, endocrinology, and physiology. Improved lamb viability at 72 h after birth was related to decreased chill indices at birth, singleton litter status, greater presuckling rectal temperature, increased ewe prelambing plasma ghrelin concentration, female sex, heavier birth weight, and decreased lamb presuckling plasma glucose concentration. Greater rectal temperatures were associated with heavier birth weight and gestation lengths shorter than 146 d, but no relationship with neonatal behavioral progression was evident. Presuckling glucose concentrations were greater in singletons and lambs born to ewes of greater BCS at d 95 of gestation, and lambs of heavier birth weight, but were also associated with decreased rectal temperatures. This might reflect a delay in glucose utilization during the adjustment from a fetal metabolic rate to a rate appropriate for cold external environments. Singleton lambs exhibited decreased presuckling plasma NEFA concentrations and were almost 8 times more likely to survive to 72 h than a twin-born lamb. Birth weight was lesser in lambs born to ewes with elevated plasma glucose and leptin concentrations before lambing and was positively related to ewe BW at d 95 of gestation and to length of gestation. Greater presuckling plasma ghrelin and leptin concentrations were measured for shorter gestation lengths. Neonate presuckling ghrelin concentrations above 650 pg/mL tended (P = 0.077) to be associated with improved lamb survival to 72 h. This was consistent with a curvilinear decline in neonate survival rates to 72 h after birth as time of latency to suckle increased. No relationship was observed between lamb plasma glucose concentrations and behavioral expression after lambing. Lambs exhibiting greater metabolic and endocrine maturity at birth had improved survival in a cold environment to 72 h after birth. The role of ghrelin in ovine fetal development warrants further investigation. PUBLICATION ABSTRACT
Uterine artery pseudoaneurysm is a rare but serious complication of pelvic surgery. Radiology has an important role in its diagnosis and primary management. We believe that this complication and its ...management are of importance to those assessing for complications following pelvic surgery. (Am J Obstet Gynecol 2001;185:1269–72.)
Background and AimsDuring seed fill in cereals, nutrients are symplasmically unloaded to vascular parenchyma in ovules, but thereafter nutrient transport is less certain. In Zea mays, two mechanisms ...of nutrient passage through the chalaza and nucellus have been hypothesized, apoplasmic and symplasmic. In a recent study, nutrients first passed non-selectively to the chalazal apoplasm and were then selectively absorbed by the nucellus before being released to the endosperm apoplasm. This study reports that the promoter of OUTER CELL LAYER3 (PSbOCL3) from Sorghum bicolor (sorghum) directs gene expression to chalazal cells where the apoplasmic barrier is thought to form. The aims were to elucidate PSbOCL3 expression patterns in sorghum and relate them to processes of nutrient pathway development in kernels and to recognized functions of the homeodomain-leucine zipper (HD-Zip) IV transcription factor family to which the promoter belongs.MethodsPSbOCL3 was cloned and transformed into sorghum as a promoter–GUS (β-glucuronidase) construct. Plant tissues from control and transformed plants were then stained for GUS, and kernels were cleared and characterized using differential interference contrast microscopy.Key ResultsA symplasmic disconnect between the chalaza and nucellus during seed fill is inferred by the combination of two phenomena: differentiation of a distinct nucellar epidermis adjacent to the chalaza, and lysis of GUS-stained chalazal cells immediately proximal to the nucellar epidermis. Compression of the GUS-stained chalazal cells during kernel maturation produced the kernel abscission zone (closing layer).ConclusionsThe results suggest that the HD-Zip IV transcription factor SbOCL3 regulates kernel nutrition and abscission. The latter is consistent with evidence that members of this transcription factor group regulate silique abscission and dehiscence in Arabidopsis thaliana. Collectively, the findings suggest that processes of floral organ abscission are conserved among angiosperms and may in some respects differ from processes of leaf abscission.
PURPOSE: This paper reports on the design of a community-based study focusing on the effects of prevalent and incident disease and other modifying influences, on changes in functioning among ...moderately and severely disabled elderly women over a 3-year period the Women's Health and Aging Study (WHAS).
METHODS: An approach to conceptualizing and assessing disability which captured functional difficulty across a broad range of activities and tasks was developed, tested on existing national data, and used, in the form of a brief screening instrument, to identify moderately to severely disabled elderly women in a large community sample representative of women 65 and older. Women meeting study criteria were recruited for a baseline interview, a 3-hour in-home clinical exam, as well as follow-up interviews and physical performance tests at 6-month intervals for three years.
RESULTS: Prevalence of moderate to severe disability among the screened population proved similar to that expected from analysis of national data (about one-third). The screening interview response rate was 78%, and 71% of women eligible by disability criteria participated. Only women completing both the baseline interview and clinical exam were counted as respondents. Analysis of characteristics of participants and nonparticipants indicated no selection bias related to levels of disability. However, education, race, and age were associated with participation. Women with some college education, black women, and younger women were more likely to participate.
CONCLUSIONS: The approach used to identify and recruit moderately to severely disabled elderly women in the WHAS is both feasible and applicable to other community-based research where inclusion of elderly people with moderate to severe disability across several areas of functioning is an objective. Other aspects of study design, such as use of proxy respondents, will also affect recruitment of individuals with impaired functioning into epidemiologic studies.
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