124 research outputs found
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Development of in vitro lily scale budlets as related to virus elimination
Lily hybrids vary in their ability to produce
virus-free (VF) bulblets when grown from virus-infected
scales in tissue culture. Asiatic hybrids typically
produce a higher percentage of in vitro VF scale bulblets
than do Lilium longiflorum cultivars. Three hypotheses
concerning the cause of this variation are tested on five
lily hybrids: an Asiatic hybrid, two L. longiflorum
cultivars, an Oriental hybrid and L. candidum.
The first hypothesis states that VF scale bulblets
originate from wound tissue that is naturally low in virus
concentration and blocks the passage of virus particles
from one cell to the next. The second hypothesis says that
scale-to-bulblet vascular connections, which serve as virus
pathways, occur in hybrids showing high percentages of
virus-infected scale bulblets, while connections are absent
in those hybrids with low numbers of virus-infected
bulblets. The third hypothesis concerns the virus
concentration in the scale at the site of bulblet origin:
bulblets of hybrids producing large numbers of VF bulblets
originate from scale tissues low in virus concentration;
bulblets of low percentage VF bulblet hybrids originate
from scale tissues high in virus concentration.
The first two hypotheses are not supported by the
results of this study. First, lily bulblets do not
originate from wound tissue. Second, scale-to-bulblet
vascular connections consistently occur in 'Enchantment,'
an Asiatic hybrid, and occasionally occur in L. candidum.
Vascular connections are not detected in the low VF bulblet
producers, L. longiflorum cultivars 'Ace' and 'Nellie
White,' nor are they seen in the Oriental hybrid
'Stargazer.'
Speculative support exists for the third hypothesis
concerning uneven virus concentration in the scale.
Distinct virus particles are observed with the electron
microscope in the double virus-infected L. longiflorum
cultivars and not in the other singly-infected lilies. The
doubly-infected lilies produce a continuous layer of
divided cells in the adaxial subepidermis of the scale
where bulblets originate, whereas the singly-infected
lilies produce cell division masses in the same area but
only beneath forming bulblets.
This study suggests that virus particles in
L. longiflorum cultivars are more uniformly distributed
than particles in the other lilies examined. This occurs
not only at the site of bulblet origin but also throughout
the scale mesophyll. Whether this is due to concurrent
viral infection or to hybrid variation is unknown
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Work, Employment and the Public Good: An Essay on the Potentials of Public Service Employment
This thesis proposes a solution to two problems: people, able and willing to work, who are unable to find meaningful jobs, and the lack of certain public services. The proposed solution is for the federal government, in conjunction with state and local governments, to provide needed public services by utilizing the manpower available in the pools of the unemployed, the underemployed, and the secondary labor force, including welfare recipients who are able and willing to work. This public service employment would consist of meaningful jobs with chances for advancement and a pay scale which would provide a decent standard of living for all those employed. Such a program of coordination of the problems of unemployment (especially unemployment which results in poverty) and the need for public services will result in positive short term social benefits and long term social and economic benefits. The thesis is divided into chapters, each dealing with a particular aspect of the problem or the proposed solution. Chapter I is a rationale for the choice of employment (work) as the vehicle for achieving some of this nation\u27s goals, notably the goal of eliminating poverty. Chapter II is a precis on poverty, analyzing some of the causes of poverty, the kinds of poor who could be helped by a program of employment, and some of the problems which would be encountered by employing the poor. Chapter III delves into the types of unemployment, pointing out the characteristics of those workers who would be most interested and most helped by a program of public service employment. Chapter IV discusses the forces which go into determining the labor force participation rates for different demographic groups. These trends make it possible to estimate roughly the numbers of people who would be interested in public service employment. Chapters II, III, and IV, in a broad sense, form a unit concerned with the possible supply of public service employment workers. Chapter V deals with the demand side of public service employment. It suggests types of services which are needed in the United States and, in some cases, guidelines for the number of people needed in order to supply these services. Chapter VI is a brief historical summary of some of the public employment programs which form a basis and precedent for this proposal of public service employment. The emphasis is on programs of the 1930\u27s and the 1960\u27s. The final chapter, Chapter VII, is a proposal for public service employment and an evaluation of it. Some parts of the proposal are specific, in order to answer specific criticisms of previous public employment programs. Other parts of the proposal are more general and offer great latitude for other ideas. There is no pretense that this is a final solution for the problems of poverty, unemployment, and the need for more services; it serves as a contribution toward the continuing debate over solutions to these problems
CFEOM1, the classic familial form of congenital fibrosis of the extraocular muscles, is genetically heterogeneous but does not result from mutations in ARIX
BACKGROUND: To learn about the molecular etiology of strabismus, we are studying the genetic basis of 'congenital fibrosis of the extraocular muscles' (CFEOM). These syndromes are characterized by congenital restrictive ophthalmoplegia affecting muscles in the oculomotor and trochlear nerve distribution. Individuals with the classic form of CFEOM are born with bilateral ptosis and infraducted globes. When all affected members of a family have classic CFEOM, we classify the family as a CFEOM1 pedigree. We have previously determined that a CFEOM1 gene maps to the FEOM1 locus on chromosome 12cen. We now identify additional pedigrees with CFEOM1 to determine if the disorder is genetically heterogeneous and, if so, if any affected members of CFEOM1 pedigrees or sporadic cases of classic CFEOM harbor mutations in ARIX, the CFEOM2 disease gene. RESULTS: Eleven new CFEOM1 pedigrees were identified. All demonstrated autosomal dominant inheritance, and nine were consistent with linkage to FEOM1. Two small CFEOM1 families were not linked to FEOM1, and both were consistent with linkage to FEOM3. We screened two CFEOM1 families consistent with linkage to FEOM2 and 5 sporadic individuals with classic CFEOM and did not detect ARIX mutations. CONCLUSIONS: The phenotype of two small CFEOM1 families does not map to FEOM1, establishing genetic heterogeneity for this disorder. These two families may harbor mutations in the FEOM3 gene, as their phenotype is consistent with linkage to this locus. Thus far, we have not identified ARIX mutations in any affected members of CFEOM1 pedigrees or in any sporadic cases of classic CFEOM
Clinical characteristics of cyclodeviation
PURPOSE: To retrospectively evaluate the incidence of cyclodeviation among patients with diplopia and analyse the causative diseases and clinical manifestations of cyclodeviation. METHODS: The medical records of 266 consecutive patients of 15 years of age or older presenting with diplopia, who had undergone the Lancaster red-green test (LRGT) from January 2001 to December 2002, were retrospectively reviewed. The presence of cyclodeviation on LRGT, predisposing conditions, causative diseases, and clinical manifestations of cyclotropia were analysed. Cyclodeviation on the LRGT were compared with those from the Maddox double-rod test (MDRT) and fundus photography. RESULTS: A total of 63 (24%) out of 266 patients exhibited cyclodeviation on LRGT. Eight out of 63 patients with cyclodeviation on the LRGT complained of torsional diplopia. Superior oblique palsy (SOP) was the most common causative disease (42 patients), followed by skew deviation (six) and thyroid orbitopathy (three). Excyclodeviation was found in 57 patients and incyclodeviation in four patients on the LRGT. The spontaneous recovery rate was 83% in patients of vascular origin and 17% of traumatic origin. Cyclodeviation with the MDRT and fundus photography showed good correlation with those obtained from the LRGT. There was no association of the amount of cyclotropia with the presence of torsional diplopia as well as with its recovery. CONCLUSION: In spite of the rare complaint of torsional diplopia, 24% of the patients with diplopia showed cyclodeviation on the LRGT. SOP was the most common causative disease. Most of the patients with cyclodeviation of a vascular origin showed spontaneous improvement
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