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51.
Branchini BR Ablamsky DM Murtiashaw MH Uzasci L Fraga H Southworth TL 《Analytical biochemistry》2007,361(2):253-262
Light emission from the North American firefly Photinus pyralis, which emits yellow-green (557-nm) light, is widely believed to be the most efficient bioluminescence system known, making this luciferase an excellent tool for monitoring gene expression. We present studies on the production of a set of thermostable red- and green-emitting luciferase mutants with bioluminescent properties suitable for dual-color reporter assays, biosensor measurements with internal controls, and imaging techniques. Starting with the luciferase variant Ser284Thr, we introduced the mutations Thr214Ala, Ala215Leu, Ile232Ala, Phe295Leu, and Glu354Lys to produce a new red-emitting enzyme with a bioluminescence maximum of 610 nm, narrow emission bandwidth, favorable kinetic properties, and excellent thermostability at 37 degrees C. By adding the same five changes to luciferase mutant Val241Ile/Gly246Ala/Phe250Ser, we produced a protein with an emission maximum of 546 nm, providing a set of thermostable enzymes whose bioluminescence maxima were separated by 64 nm. Model studies established that the luciferases could be detected at the attomole level and six orders of magnitude higher. In microplate luminometer format, mixtures containing 1.0 fmol total luciferase were quantified from measurements of simultaneously emitted red and green light. The results presented here provide evidence that it is feasible to monitor two distinct activities at 37 degrees C with these novel thermostable proteins. 相似文献
52.
Fushi Wen Ho Hyung Woo Elizabeth A. Pierson Toril D. Eldhuset C. G. Fossdal N. E. Nagy Martha C. Hawes 《Plant Molecular Biology Reporter》2009,27(1):58-68
Root cap development in cereals and legumes is self-regulated by a repressor that accumulates in the extracellular environment,
and immersing the root tip into water results in renewed cap development. By exploiting this phenomenon, root cap mitosis
and differentiation can be synchronously induced among populations. In Pisum sativum L., messenger RNA (mRNA) differential display revealed changes in expression of approximately 1% of the sample mRNA population
within minutes of induced cap turnover. This profile changes sequentially over a period of 30 min, then stabilizes. Microarray
analysis of Medicago truncatula root caps confirmed changes in expression of approximately 1% of the target population, within minutes. A cell specific marker
for cap turnover exhibited the same temporal and spatial expression profile in the gymnosperm species Norway spruce (Picea abies) as in pea. Induced cap development provides a means to profile cell-specific gene expression among phylogenetically diverse
species from the early moments of mitosis and cellular differentiation. 相似文献
53.
Julien Cappelle Delong Zhao Marius Gilbert Martha I. Nelson Scott H. Newman John Y. Takekawa Nicolas Gaidet Diann J. Prosser Ying Liu Peng Li Yuelong Shu Xiangming Xiao 《EcoHealth》2014,11(1):109-119
For decades, southern China has been considered to be an important source for emerging influenza viruses since key hosts live together in high densities in areas with intensive agriculture. However, the underlying conditions of emergence and spread of avian influenza viruses (AIV) have not been studied in detail, particularly the complex spatiotemporal interplay of viral transmission between wild and domestic ducks, two major actors of AIV epidemiology. In this synthesis, we examine the risks of avian influenza spread in Poyang Lake, an area of intensive free-ranging duck production and large numbers of wild waterfowl. Our synthesis shows that farming of free-grazing domestic ducks is intensive in this area and synchronized with wild duck migration. The presence of juvenile domestic ducks in harvested paddy fields prior to the arrival and departure of migrant ducks in the same fields may amplify the risk of AIV circulation and facilitate the transmission between wild and domestic populations. We provide evidence associating wild ducks migration with the spread of H5N1 in the spring of 2008 from southern China to South Korea, Russia, and Japan, supported by documented wild duck movements and phylogenetic analyses of highly pathogenic avian influenza H5N1 sequences. We suggest that prevention measures based on a modification of agricultural practices may be implemented in these areas to reduce the intensity of AIV transmission between wild and domestic ducks. This would require involving all local stakeholders to discuss feasible and acceptable solutions. 相似文献
54.
Investigating sexual dimorphism is important for our understanding of its influence on reproductive strategies including male-male competition, mate choice, and sexual conflict. Measuring physical traits in wild animals can be logistically challenging and disruptive for the animals. Therefore body size and ornament variation in wild primates have rarely been quantified. Gorillas are amongst the most sexually dimorphic and dichromatic primates. Adult males (silverbacks) possess a prominent sagittal crest, a pad of fibrous and fatty tissue on top of the head, have red crest coloration, their saddle appears silver, and they possess a silverline along their stomach. Here we measure levels of sexual dimorphism and within-male variation of body length, head size, and sexual dichromatism in a population of wild western gorillas using photogrammetry. Digital photogrammetry is a useful and precise method to measure sexual dimorphism in physical traits yielding sexual dimorphism indices (ISD), similar to those derived from traditional measurements of skeletal remains. Silverbacks were on an average 1.23 times longer in body length than adult females. Sexual dimorphism of head size was highest in measures of crest size (max ISD: 60.4) compared with measures of facial height (max ISD: 24.7). The most sexually dimorphic head size measures also showed the highest within-sex variation. We found no clear sex differences in crest coloration but there was large sexual dichromatism with high within-male variation in saddle coloration and silverline size. Further studies should examine if these sexually dimorphic traits are honest signals of competitive ability and confer an advantage in reproductive success. 相似文献
55.
Martha Patricia Lpez Adriana Paola Ulloa Fabio Alberto Escobar 《Biomédica : revista del Instituto Nacional de Salud》2022,42(1):159
Introduction:
Prison population is affected by tuberculosis (TB) due to prison overcrowding. This situation reflects an inequity in health, understood as an unfair and avoidable difference between individuals and populations.Objective:
To estimate the conditions of prison overcrowding as health inequity in prison population suffering from TB in Colombia during 2018.Materials and methods:
This is an ecological study to estimate inequities at the national level in prison population through the use of the World Health Organization methodology for the measurement of inequalities. Based on data from the public health surveillance system, the incidence of TB was taken as an indicator and the percentage of overcrowding as an equity stratifier. Simple and complex measures of inequality were calculated.Results:
The relative inequality between the lowest and highest quintiles of crowding showed that TB incidence among prison population with the highest crowding was 1.92 times that of the group with the lowest crowding. The inequality index identified an excess of 724 TB cases per 100,000 among those with the highest concentration of overcrowding. The health concentration index was -0.121, which shows that the incidence was concentrated in the group with the most overpopulation.Conclusion:
In Colombia, prison population in overcrowded conditions and suffering from TB has to face unfair and avoidable inequalities as compared with those not living in these conditions. Policies are required to reduce overcrowding and improve living conditions in prisons. 相似文献56.
Martha J. Somerman 《Gerodontology》1987,6(2):59-66
Medications used for the management of the Alzheimer's patient are of two types: agents prescribed for treatment of cognitive disorders and agents used for symptomatic relief of mood disorders. This article reviews the mechanisms of action and side-effects of the more common of these agents. In addition, dental management of the Alzheimer's patient is discussed in relation to specific medications being taken. 相似文献
57.
Martha Ludwig 《Photosynthesis research》2013,117(1-3):147-161
The biochemistry and leaf anatomy of plants using C4 photosynthesis promote the concentration of atmospheric CO2 in leaf tissue that leads to improvements in growth and yield of C4 plants over C3 species in hot, dry, high light, and/or saline environments. C4 plants like maize and sugarcane are significant food, fodder, and bioenergy crops. The C4 photosynthetic pathway is an excellent example of convergent evolution, having evolved in multiple independent lineages of land plants from ancestors employing C3 photosynthesis. In addition to C3 and C4 species, some plant lineages contain closely related C3–C4 intermediate species that demonstrate leaf anatomical, biochemical, and physiological characteristics between those of C3 plants and species using C4 photosynthesis. These groups of plants have been extremely useful in dissecting the modifications to leaf anatomy and molecular biology, which led to the evolution of C4 photosynthesis. It is now clear that great variation exists in C4 leaf anatomy, and diverse molecular mechanisms underlie C4 biochemistry and physiology. However, all these different paths have led to the same destination—the expression of a C4 CO2 concentrating mechanism. Further identification of C4 leaf anatomical traits and molecular biological components, and understanding how they are controlled and assembled will not only allow for additional insights into evolutionary convergence, but also contribute to sustainable food and bioenergy production strategies. 相似文献
58.
Ariana M. Chao Thomas A. Wadden Robert I. Berkowitz George Blackburn Paula Bolin Jeanne M. Clark Mace Coday Jeffrey M. Curtis Linda M. Delahanty Gareth R. Dutton Mary Evans Linda J. Ewing John P. Foreyt Linda J. Gay Edward W. Gregg Helen P. Hazuda James O. Hill Edward S. Horton Denise K. Houston John M. Jakicic Robert W. Jeffery Karen C. Johnson Steven E. Kahn William C. Knowler Anne Kure Katherine L. Michalski Maria G. Montez Rebecca H. Neiberg Jennifer Patricio Anne Peters Xavier Pi‐Sunyer Henry Pownall David Reboussin Bruce Redmon W. Jack Rejeski Helmut Steinburg Martha Walker Donald A. Williamson Rena R. Wing Holly Wyatt Susan Z. Yanovski Ping Zhang 《Obesity (Silver Spring, Md.)》2020,28(5):893-901
59.
Katharine N. Savage Kathy Burek-Huntington Sadie K. Wright Anna L. Bryan Gay Sheffield Marc Webber Raphaela Stimmelmayr Pam Tuomi Martha A. Delaney William Walker 《Marine Mammal Science》2021,37(3):843-869
Presented here is the first comprehensive and updated compilation of history, distribution, and findings of Stejneger's beaked whales (Mesoplodon stejnegeri) in Alaska. Stejneger's beaked whales are a poorly understood, elusive, deep-diving cetacean species found in the North Pacific Ocean. Since Stejneger's beaked whale strandings data in Alaska through 1994 were last published, 35 additional strandings have been documented. Twenty-seven animals stranded in the Aleutian Islands, seven stranded in Southcentral Alaska, and one animal stranded on St. Lawrence Island. Twenty-two carcasses were necropsied, but only four were fresh. Seventeen of the 22 died during mass stranding events and cause of death could not be definitively determined. Barotrauma was suspected in three cases and infectious disease possibly complicated by barotrauma occurred in two cases. We documented an expansion of strandings into the northern Bering Sea, characterized a sex bias, examined stomach contents that included macroplastic, and identified parasites not previously associated with Stejneger's beaked whales. Also included are data on the largest known mass stranding of Stejneger's beaked whales, which occurred on Adak Island in 2018. The history, distribution, and findings presented here are central to further our understanding of this species. 相似文献
60.
Mette K. Schiønning Martha Gosch Eileen Dillane Michelle Cronin Mark J. Jessopp 《Marine Mammal Science》2021,37(2):533-545
Recoveries of gray seal (Halichoerus grypus) populations across their eastern Atlantic distribution have led to a steady increase in seal-fishery interactions. Fishers have estimated depredation of salmonids (Salmo spp.) and monkfish (Lophius spp.) as high as 40% and 59% respectively in Ireland. However, empirical evidence for the consumption of these species has been extremely limited due to diagnostic hard part remains not being found in scats or stomach samples. We applied species-specific primers and tested for the presence of monkfish and salmonids in gray seal diet genetically using quantitative polymerase chain reaction (qPCR) on scats. Monkfish occurred in 29.7% of sampled scats, while salmonids occurred in 12.7%. Seasonal and regional variability in occurrence were noted for both species, likely related to the migratory behavior of the prey species and proximity of seal haul-outs to aquaculture sites. Traditional hard part analysis of scats, including scats that tested positive for monkfish and salmonid DNA, failed to find any evidence of either species. This study provides important empirical evidence for the consumption of these species in Ireland that can inform management. 相似文献