877 research outputs found
Performa Pertumbuhan Indigofera zollingeriana pada Media Tanam yang Berbeda di Sulawei Tengah
Potensi hijauan pakan ternak (HPT) unggul di Sulawesi Tengah perlu lakukan sebuah pengembangan secara masif sehingga penyebaran HPT utamanya legum dapat merata di wilayah Sulawesi Tengah. Masih minimnya informasi terkait dengan persemian legum Indigofera Zollingeriana. di media tanam yang berbeda khususnya di Sulawesi Tengah menjadi tantangan untuk pengembangan legum serta terbatasnya kebun induk bibit. Tantangan ini dapat dijawab dengan pengembangan HPT unggul salah satu yang cukup potensional adalah tanaman legume. Indigofera S.p sangat cocok dengan topografi, mikroklimat serta kondisi lingkungan di Sulawesi Tengah.Penelitian ini bertujuan untuk mengkaji performa pertumbuhan Indigofera Zollingerianapada media tanam yang berbeda di Sulawesi Tengah.Hasil penelitian memperlihatkan jumlah daun, batang dan tinggi pada setiap perlakukan, Perlakuan P3 memperlihatkan hasil yang terbaik dibandingkan yang lainya. Hasil dari penelitian diharapkan dijadikan rujukan rekomendasi alternatif solusi terhadap permasalahan keterbatasan di Sulawesi Tengah khususnya di peternakan rakyat
Systematics of geometric scaling
Using all available data on the deep-inelastic cross-sections at HERA at
x<0.01, we look for geometric scaling of the form \sigma^{\gamma^*p}(\tau)
where the scaling variable \tau behaves alternatively like \log(Q^2)-\lambda Y,
as in the original definition, or \log(Q^2)-\lambda \sqrt{Y}, which is
suggested by the asymptotic properties of the Balitsky-Kovchegov (BK) equation
with running QCD coupling constant. A ``Quality Factor'' (QF) is defined,
quantifying the phenomenological validity of the scaling and the uncertainty on
the intercept \lambda. Both choices have a good QF, showing that the second
choice is as valid as the first one, predicted for fixed coupling constant. A
comparison between the QCD asymptotic predictions and data is made and the QF
analysis shows that the agreement can be reached, provided going beyond leading
logarithmic accuracy for the BK equation.Comment: 4 pages, 4 figure
Germline mutations in retinoma patients: Relevance to low-penetrance and low-expressivity molecular basis
PURPOSE: To study phenotype-genotype correlation in patients who have retinoma, which is a benign tumor resembling the post irradiation regression pattern of retinoblastoma (RB). METHODS: We selected patients who had retinoma and positive family history for RB and patients who had retinoma in one eye and either retinoma or RB in the other eye. The study included 22 patients with available DNA: 18 from 11 families and four sporadic cases. DNA was extracted from peripheral blood leukocytes. The RB1 gene was screened by DHPLC and direct sequencing of the promoter and all the exons. RESULTS: We identified 17 occurrences of 11 distinct germline mutations in two sporadic and in 15 familial cases (nine families). The 11 identified mutations were located in exons 1, 10,11,13,14, and 19 to 23. Four of the identified mutations were not previously reported, including g.64407delT, g.153236A>T, g.156743delTCTG, and g.162078delA. Eight out the 11 mutations were truncating and three were nontruncating (missense). There was no correlation between the type of mutation and the number of tumor foci per eye (RB or retinomas). Highly heterogeneous intrafamilial expressivity was observed. CONCLUSIONS: To our knowledge, this study is the largest series of mutations of consecutive retinoma patients. The present data suggest that the type of inherited mutations underlying retinoma is undistinguishable from RB related ones, i.e., largely dominated by truncating mutants. This finding is in contrast with the RB1 genotypic spectrum of mutations associated with low-penetrance RB, i.e., nontruncating mutants. The molecular mechanism underlying low-penetrance and attenuated expressivity (retinomas) appeared to be distinct
On the linearization of the generalized Ermakov systems
A linearization procedure is proposed for Ermakov systems with frequency
depending on dynamic variables. The procedure applies to a wide class of
generalized Ermakov systems which are linearizable in a manner similar to that
applicable to usual Ermakov systems. The Kepler--Ermakov systems belong into
this category but others, more generic, systems are also included
Effect of selection on ancestry: an exactly soluble case and its phenomenological generalization
We consider a family of models describing the evolution under selection of a
population whose dynamics can be related to the propagation of noisy traveling
waves. For one particular model, that we shall call the exponential model, the
properties of the traveling wave front can be calculated exactly, as well as
the statistics of the genealogy of the population. One striking result is that,
for this particular model, the genealogical trees have the same statistics as
the trees of replicas in the Parisi mean-field theory of spin glasses. We also
find that in the exponential model, the coalescence times along these trees
grow like the logarithm of the population size. A phenomenological picture of
the propagation of wave fronts that we introduced in a previous work, as well
as our numerical data, suggest that these statistics remain valid for a larger
class of models, while the coalescence times grow like the cube of the
logarithm of the population size.Comment: 26 page
Variable phenotypic expressivity in a Swiss family with autosomal dominant retinitis pigmentosa due to a T494M mutation in the PRPF3 gene
PURPOSE: To characterize the clinical, psychophysical, and electrophysiological phenotypes in a five-generation Swiss family with dominantly inherited retinitis pigmentosa caused by a T494M mutation in the Precursor mRNA-Processing factor 3 (PRPF3) gene, and to relate the phenotype to the underlying genetic mutation. METHODS: Eleven affected patients were ascertained for phenotypic and genotypic characterization. Ophthalmologic evaluations included color vision testing, Goldmann perimetry, and digital fundus photography. Some patients had autofluorescence imaging, Optical Coherence Tomography, and ISCEV-standard full-field electroretinography. All affected patients had genetic testing. RESULTS: The age of onset of night blindness and the severity of the progression of the disease varied between members of the family. Some patients reported early onset of night blindness at age three, with subsequent severe deterioration of visual acuity, which was 0.4 in the best eye after their fifties. The second group of patients had a later onset of night blindness, in the mid-twenties, with a milder disease progression and a visual acuity of 0.8 at age 70. Fundus autofluorescence imaging and electrophysiological and visual field abnormalities also showed some degree of varying phenotypes. The autofluorescence imaging showed a large high-density ring bilaterally. Myopia (range: -0.75 to -8) was found in 10/11 affected subjects. Fundus findings showed areas of atrophy along the arcades. A T494M change was found in exon 11 of the PRPF3 gene. The change segregates with the disease in the family. CONCLUSIONS: A mutation in the PRPF3 gene is rare compared to other genes causing autosomal dominant retinitis pigmentosa (ADRP). Although a T494M change has been reported, the family in our study is the first with variable expressivity. Mutations in the PRPF3 gene can cause a variable ADRP phenotype, unlike in the previously described Danish, English, and Japanese families. Our report, based on one of the largest affected pedigree, provides a better understanding as to the phenotype/genotype description of ADRP caused by a PRPF3 mutation
Multimodale Bildgebung eines retinalen Astrozyten-Hamartoms assoziert mit angeborener Hypertrophie des retinalen Pigmentepithels [Multimodal Imaging of Retinal Astrocytic Hamartoma Associated with Congenital Hypertrophy of Retinal Pigment Epithelium]
Hamartoma is a nodular malformation, with a single or multiple malformations, it is a recognized prenatal developmental abnormality. This benign tumor lesion has the same histological components of normal parenchyma, but these components are arranged haphazardly which disrupts normal function. Hamartomas usually remain connected with the tissue of origin; as is the case with pulmonary hamartoma or the splenic hamartoma. The exact incidence of retinal astrocytic hamartoma (RAH) is not well known, but it is estimated at one case per 100 000 births per year [1]. The astrocytic hamartoma is a neuroglial tissue and produces astrocytes within the optic nerve [2], and consequently it often appears within papillary region
Noether symmetries for two-dimensional charged particle motion
We find the Noether point symmetries for non-relativistic two-dimensional
charged particle motion. These symmetries are composed of a quasi-invariance
transformation, a time-dependent rotation and a time-dependent spatial
translation. The associated electromagnetic field satisfy a system of
first-order linear partial differential equations. This system is solved
exactly, yielding three classes of electromagnetic fields compatible with
Noether point symmetries. The corresponding Noether invariants are derived and
interpreted
Dynamical symmetries and the Ermakov invariant
Ermakov systems possessing Noether point symmetry are identified among the
Ermakov systems that derive from a Lagrangian formalism and, the Ermakov
invariant is shown to result from an associated symmetry of dynamical
character. The Ermakov invariant and the associated Noether invariant, are
sufficient to reduce these systems to quadratures
Retinal stem cells transplanted into models of late stages of retinitis pigmentosa preferentially adopt a glial or a retinal ganglion cell fate
PURPOSE: To characterize the potential of newborn retinal stem cells (RSCs) isolated from the radial glia population to integrate the retina, this study was conducted to investigate the fate of in vitro expanded RSCs transplanted into retinas devoid of photoreceptors (adult rd1 and old VPP mice and rhodopsin-mutated transgenic mice) or partially degenerated retina (adult VPP mice) retinas. METHODS: Populations of RSCs and progenitor cells were isolated either from DBA2J newborn mice and labeled with the red lipophilic fluorescent dye (PKH26) or from GFP (green fluorescent protein) transgenic mice. After expansion in EGF+FGF2 (epidermal growth factor+fibroblast growth factor), cells were transplanted intravitreally or subretinally into the eyes of adult wild-type, transgenic mice undergoing slow (VPP strain) or rapid (rd1 strain) retinal degeneration. RESULTS: Only limited migration and differentiation of the cells were observed in normal mice injected subretinally or in VPP and rd1 mice injected intravitreally. After subretinal injection in old VPP mice, transplanted cells massively migrated into the ganglion cell layer and, at 1 and 4 weeks after injection, harbored neuronal and glial markers expressed locally, such as beta-tubulin-III, NeuN, Brn3b, or glial fibrillary acidic protein (GFAP), with a marked preference for the glial phenotype. In adult VPP retinas, the grafted cells behaved similarly. Few grafted cells stayed in the degenerating outer nuclear layer (ONL). These cells were, in rare cases, positive for rhodopsin or recoverin, markers specific for photoreceptors and some bipolar cells. CONCLUSIONS: These results show that the grafted cells preferentially integrate into the GCL and IPL and express ganglion cell or glial markers, thus exhibiting migratory and differentiation preferences when injected subretinally. It also appears that the retina, whether partially degenerated or already degenerated, does not provide signals to induce massive differentiation of RSCs into photoreceptors. This observation suggests that a predifferentiation of RSCs into photoreceptors before transplantation may be necessary to obtain graft integration in the ONL
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