New Classes of Partial Geometries and Their Associated LDPC Codes

The use of partial geometries to construct parity-check matrices for LDPC codes has resulted in the design of successful codes with a probability of error close to the Shannon capacity at bit error rates down to $10^{-15}$. Such considerations have motivated this further investigation. A new and simple construction of a type of partial geometries with quasi-cyclic structure is given and their properties are investigated. The trapping sets of the partial geometry codes were considered previously using the geometric aspects of the underlying structure to derive information on the size of allowable trapping sets. This topic is further considered here. Finally, there is a natural relationship between partial geometries and strongly regular graphs. The eigenvalues of the adjacency matrices of such graphs are well known and it is of interest to determine if any of the Tanner graphs derived from the partial geometries are good expanders for certain parameter sets, since it can be argued that codes with good geometric and expansion properties might perform well under message-passing decoding.Comment: 34 pages with single column, 6 figure

Feasibility of a tip grafting system for fruit breeding and its effects on cold hardiness and juvenility

The cost of new cultivar development is high due to long juvenile periods and large tree size in tree fruit breeding programs. For apples, sour cherries, and saskatoon berries, grafting seedling scions onto the tips of branches of mature plants was hypothesized to shorten the juvenile period and reduce land use under the Canadian prairie conditions. For apples, a tip grafting system (tip grafting onto mature crabapple rootstocks) was compared with the traditional grafting system (grafting onto young ‘Ottawa 3’ rootstocks). Apple scions of ‘Golden Delicious’, ‘McIntosh’, and ‘SK Prairie Sun’ which exhibit a range of inherent cold hardiness, were grafted in the spring of 2001. Over a two year period, winter survival of the scions was improved by 37% by the tip grafting system as compared to the traditional grafting system making it not feasible for evaluation of cold hardiness of scions. Vegetative growth of scions approximated the rootstocks on which the scions were grafted. Winter survival was highly correlated with shoot growth cessation (r = +0.83) and terminal bud stage (r = +0.85) observed around the time of first frost. Juvenile seedlings of saskatoon berry and sour cherry hybrids were tip grafted onto mature plants of their own species in the spring of 2000. After two growing seasons, the tip grafting system in sour cherries had reduced flowering by 69.7%, shoot length by 84%, and shoot diameter by 76% compared with the juvenile seedlings on their own roots (scion donors). Tip grafting saskatoon berry seedlings increased flowering by 68%, shoot length by 257%, and shoot diameter by 42% compared with scion donors. For sour cherries, the tip grafting system reduced winter dieback by 99.6%, hastened terminal bud development and leaf drop compared with the scion donors. Tip grafting of saskatoon berry seedlings had little effect on terminal bud development and cold hardiness of scions perhaps due to the cold hardy character of this species. For apples and sour cherries, the tip grafting system tested in this study enhanced cold hardiness of scions when combined with the appropriated rootstocks and may be useful for maintaining germplasm that otherwise would not be hardy in northern locations

Effect of combination of parenteral edaravone and nimodipine on ischemic cerebral injury following cerebral hemorrhage

Purpose: To study the clinical effects of parenteral edaravone when  combined with nimodipine for the treatment of ischemic cerebral injury following cerebral hemorrhage, and its influence on D-dimer, brain natriuretic peptide (BNP) and transcription factor kB (NF-kB) levels.Methods: A total of 102 cases of ischemic cerebral injury after cerebral hemorrhage seen in 215 Hospital of Nuclear Industry in Shanxi, China from January, 2016 to January, 2017 were included in this study. They were randomly divided into two groups, viz, fifty-two cases in control group and fifty cases in observation group. Control group received nimodipine, while the observation group was given edaravone. Before and after treatment, the two groups’ NIHSS scores were compared. Adverse reactions were recorded, and clinical effectiveness was evaluated. Enzyme-linked  immunosorbent assay (ELISA) was used to determin thee levels of serum D-dimmer, BNP and NF-kB in the two groups.Results: Before treatment, the two groups’ NIHSS scores did not show significant differences (p > 0.05). However, after treatment, the observation group’s NIHSS score was significantly lower than that of the control group (p < 0.05). Total effectiveness in the observation and control groups were 98.0 and 80.8 %, respectively. Clinical effectiveness in patients in the observation group was significantly better than that of the control group (p < 0.05). Before treatment, D-dimmer, BNP and NF-kB levels of patients in the two groups showed no significant difference (p > 0.05). However, compared with the control group, D-dimmer, BNP and NF-kB levels in the observation group post-treatment decreased significantly (p < 0.05).Conclusion: These results suggest that the combination of parenteral  edaravone and nimodipine has relatively high efficiency and safety, mitigates cerebral ischemia and cerebral edema, and controls inflammatory reactions. Thus, its potentials in this regard requires further investigation.Keywords: Edaravone, Nimodipine, Cerebral ischemia, Ischemic cerebral injur