Some Remarks on Cocks'Identity-Based Encryption Scheme

The theory of quadratic residues plays an important role in cryptography.In 2001,Cocks developed an identity-based encryption(IBE)scheme based on quadratic residues,resolving Shamir’s 17-year-old open problem.However,a notable drawback of Cocks’scheme is the significant expansion of the ciphertext,and some of its limitations have been addressed in subsequent research.Recently,Cotan and Teşeleanu highlighted that previous studies on Cocks’scheme relied on a trial-and-error method based on Jacobi symbols to generate the necessary parameters for the encryption process.They enhanced the encryption speed of Cocks’scheme by eliminating this trialand-error method.Based on security analysis,this study concludes that the security of Cotan-Teşeleanu’s proposal cannot be directly derived from the security of the original Cocks’scheme.Furthermore,by adopting the Cotan-Teşeleanu method and introducing an additional variable as a public element,this study develops a similar enhancement scheme that not only accelerates the encryption speed but also provides security equivalent to the original Cocks’scheme.

基于Cocks身份密码体制的高效签密方案

现有的基于身份签密方案多是基于双(多)线性对构造的,针对其复杂的对运算导致签密效率低下的问题,基于Cocks的身份密码体制提出了一种新的高效签密方案。首先,形式化所提方案的安全模型,给出了保密性和不可伪造性的定义;然后,利用二次剩余难解问题实现了所提方案的具体构造,进一步结合雅可比符号运算巧妙地在一个逻辑步骤内实现了签密算法设计;最后,在随机预言模型下,给出了所提方案满足保密性和不可伪造性的安全性证明。效率分析表明,相对于已有的基于身份签密的方案,所提方案较大幅度地提升了运算效率,同时具备基于身份密码的良好特性。

Use of factor scores for determining the relationship between body measurements and semen traits of cocks

Semen evaluation is required to predict fertility. In most rural African communities, facilities for microscopic evaluation of semen are not available. Therefore, an indirect method of predicting semen traits of cocks is required by poultry farmers. The objective of this study was to use factor scores derived from factor analysis of body measurements to predict some semen traits of cocks. Correlation matrix was obtained by calculating the correlations between body measurements and semen traits of cocks. Kais-er-Meyer-Olkin (KMO) measure of sampling adequacy and Bartletts test of sphericity were used to test the appropriateness of factor analysis on the data. The extraction of the factors was done by calculating the eigenvalues of the correlation matrix. Variance maximizing rotation of the transformation matrix was done to facilitate the interpretation of the factor loadings. Two factors with eigenvalues greater than 1 were extracted which accounted for 76.96% of the variations present in the original variables. The two factors were used to obtain the factor score coefficients. When utilized as independent variables in multiple regression analysis, the two factors explained 53.20% and 40.80% of the variations in sperm motility and sperm concentration respectively. Factor 1 had more impact on sperm motility than factor 2 as it was significantly related to it. Factor 2 was significantly more related to sperm concentration than factor 1. The relationship between body measurements and semen volume, live sperm and abnormal sperm were weak and mostly negative. Therefore, they were not predicted using factor scores.

Cock年话“鸡”

根据十二生肖,1993年出生的人属“Cock鸡”,1993年为鸡年。汉语有“呆若木鸡;鸡飞蛋打;鹤立鸡群;鸡犬之声相闻,者死不相往来;鸡犬升天;杀鸡焉用宰牛刀”等之说。那么,英语有关“鸡”的说法又有哪些呢?本文将就此作如下探讨。一、与“鸡”有关的常用英语词语: cock/rooster 公鸡,hen 母鸡,chicken 小鸡,鸡肉,chick

Aphrodisiac potential of Polyalthia bullata (Tongkat Ali) in fowl

Objective:To study the aphrodisiac potential of Polyalthia(P.)bullata in fowl.Methods:In this study,testosterone,as an indicator of the aphrodisiac potential of P.bullata,was investigated for its release from TM3 Leydig cells grown in vitro and in 4 fowls given capsules containing P.bullata at a dose of 10 mg in each capsule twice a day,for 50 days.In the latter in vivo evaluation,mating behaviours were additionally determined after the treated fowls were released to the individual hens,and their testes and liver were dissected for histological examinations.Blood drawn from the fowls was assessed for any changes in diagnostic parameters.Results:In the in vitro test(TM3 Leydig cells),P.bullata was able to increase testosterone to 0.48 nmol/L within 72 h of incubation,compared to the untreated control with only 0.18 nmol/L,i.e.,an increase of 170%.In the in vivo test,outcomes in the fowls dosed with P.bullata showed similar positive elevations of testosterone to(9.72±1.10)nmol/L in comparison to the controls that showed a level of only(4.05±0.84)nmol/L.Total frequencies of mating behaviours were observed(wing flapping,body shakes,crowing and beak pecking)to be 23 counts for the test compared to only 15 for the control fowls.Histological examination of the male reproductive organs provided evidence of testosterone boosting based on an observable increase in the activity at the seminiferous tubules of testis tissues without any damaging effects,compared to the controls.In the nine diagnostic blood parameters assessed,including alanine aminotransferase,aspartate aminotransferase,and gamma glutamyltransferase,none was remarkably elevated compared to the controls.The histological changes in the liver were not severe and mainly consisted of only localized moderate but recoverable obstructions and swellings of the vessels and tubules.Conclusions:P.bullata is able to boost testosterone both in vitro and in vivo,with no acute toxicities.

Methods and Effects of Hongshan Cock Spermatozoa Cryopreservation

The survival rates, acrosomic integrity rates of frozen semen from Hongshan cock and fertilities of the frozen-thawed spermatozoa in both pellets and straws were studied. The result shows that the average survival rate of spermatozoa in straws was 0, 451±0, 056, and 0. 390±0. 040 in pellets, the former was significantly higher than the later （n=20, p〈0, 01）, The average acrosomic integrity rate of the sperms was 0, 613±0. 049 in straws, and 0. 476±0. 057 in pellets. The former was significantly higher than the later （n= 20, p〈0.05）. The fertility rates （%） of sperms in pellets, straws and freshly colleered semen at the third day after artificial insemination （AI） were 85.32±2. 32, 87. 73±1.00 and 90.77±1.68, respectively. The fertility rate,s of the three types of semen at the fourth and fifth days were lower than the third day＇s. Variance analysts shows that the fertilities of the spermatozoa in pellets and straws were significantly lower than freshly collected semen （n=3, p〈0.01）, and the fertilities of the spermatozoa in straws were significantly higher than those in pellets （n= 3, p〈0.01）.

The Effect of Different Levels of Salinity and Potassium Nitrate on the Germination of Cocks Comb (<i>Celosia cristata</i>)

Cocks Comb (Celosia cristata) is a hot-season annual species which is grown from seeds. A study was carried out in the horticulture laboratory of Gorgan University of Agriculture Science and Natural Resources of February 2013 to evaluate the impact of salinity and potassium nitrate on the germination of cockscomb with five salinity levels (0, &minus;2, &minus;4, &minus;6, and &minus;8 bars) and three potassium nitrate levels (0%, 0.2%, and 0.4%) at 25&deg;C on the basis of a Randomized Complete Block Design. Analysis of variance showed significant differences among salinity levels in germination percentage, radicle length, plumule length, and seed vigor at the 1% probability level. Mean comparison for germination percentage revealed that higher salinity reduced seed germination percentage so that it was decreased from 80% in no salinity to 15% in &minus;8 dS&sdot;m&minus;1. The highest percentage of germination was related to zero percent salt and potassium nitrate 0.2%. Also, the highest radicle length of 2.48 cm was related to no salinity and the lowest one (0.61 cm) to &minus;6 dS salinity. The highest radicle length and seed vigor were also observed in no salinity. Potassium nitrate by itself had no impact on the measured traits. Among interactions between salinity and potassium nitrate, the highest germination percentage was observed under 0 salinity × 0.2% potassium nitrate.

Comparison of the Anthelmintic Efficacy of Three Commercial Products against Ascarids and Capillaria SPP. in Fighting Cocks

The aim of the present study was to evaluate the anthelmintic efficacy of three commercial compounds against ascarids and Capillaria spp. in naturally infected fighting cocks from Mexico. First experiment.- Forty cocks were selected on the basis of eggs per gram (EPG) counts quantified by the McMaster method. On day 0 the birds were divided into four groups of 10 cocks, each subjected to the treatments. Group 1 received a single oral dose of 1 mg of ivermectin, 25 mg of praziquantel and 40 mg of fenbendazole given in tablets according to body weight (b.w). Group 2 was treated with a single oral dose of 1 mg of ivermectin, 25 mg of praziquantel and 40 mg of fenbendazole given in tablets/b.w. but formulated with a different excipient. Group 3 received a single tablet containing 0.2 mg of abamectin and 30 mg of albendazole. Group 4 served as a non-treated control. Fecal analyses were carried out on days 0 (day of treatment), 7, 14, 21 and 28, being collected from the floor where the cocks were individually caged. Efficacy was measured on the percentage of egg reduction from day 0 with respect the EPG counts from the control group. In a second experiment the study was similarly performed using another cock-farm located at approximately 300 km away from the first one. Results indicated an overall efficacy of 100%, 94.0% and 100% for groups 1, 2 and 3 in the first experiment and 100%, 100%, 100% for groups 1, 2 and 3 of the 2nd experiment, respectively. It is concluded that all drugs used exerted high efficacy in fighting cocks naturally infected with helminths.

The Temporal and Spatial Variability of the Phenological Phases Connected with the Pollen Season of the Main ＂Allergens＂ in the Czech Republic within the Period 1991-2010

Nature and its exploration is one of the most frequent objects of scientific research. Phenology can be described either as the study of natural events, or of biological events, in relation to climate. The Czech Hydrometeorological Institute operates phenological network （45 wild plants） with allergology important species within the observation program （the program includes among other species also the Common Hazel （Corylus avellana L.）, the Common Alder （Alnus glutinosa （L.） Gaert.）, the Silver Birch （Betula pendula Roth.）, the Meadow Foxtail （Alopecurus pratensis L.） and the Cocks Foot （Dactyl＆ glomerata L.））. We have statistically evaluated the phenological stages closely connected with the pollen grains release into the air （the beginning of flowering-BBCH 61 and the end of flowering-BBCH 69） including maps creation. The processed period was within last twenty years 1991-2010. The maps were processed using geographic information systems （Application Clidata-GIS, method Clidata-DEM）. The input data were used the mean dates of phenophase entrance from the twenty year period 1991-2010. The mean onset date of the beginning of flowering was between 24th February and the 24th March （the Common Hazel）, between 6th March and 2nd April （the Common Alder）, between 13th April and 7th May （the Silver Birch）, between 5thMay and 23rd May （the Meadow Foxtail） and between 16th May and 12th June （the Cocks Foot）. The mean onset date of the end of flowering was from 18th March till the 15th April （the Common Hazel）, from 27th March till 19th April （the Common Alder）, from 28th April till 21st May （the Silver Birch）, from 25th May till 6th June （the Meadow Foxtail） and from 7th May till 23rd June （the Cocks Foot）. The duration of flowering lasts on average with selected allergens as follows： 22-23 days with standard deviation 2.3-5.3 days （the Common Hazel）, 14-15 days with standard deviation 2.1-2.7 days （the Common Alder）, 17-21 days with standard deviation 1.8-4.2 days （the Silver Birch）, 20 days with standard deviations 1.0-2.7 days （the Meadow Foxtail） and 20-22 days with standard deviation 1.3-4.0 days （the Cocks Foot）. The phenological phases were much precipitated in the years 2000, 2007 and 2009, on the contrary the onsets were much delayed in the years 1991 and 1996. Part of selected species show an overall tendency to the earlierst onset on the low level of the statistics significance during the 20-year processed period.

鸡年话"鸡"

2005年是农历乙酉鸡年，鸡谐音“吉”，因而鸡常被人们看作是吉祥如意的象征．自古以来，人们把鸡塑造成驱邪纳福的使者：在我国。各种国画系列中的雄鸡报晓，名鸡献福，金鸡报春等倍受人们青睐。

Habitat selection of the Tibetan Snow Cock Tetraogallus tibetanus in the spring in Lhasa

The habitat selection of Tibetan Snow Cocks in shrub vegetation was investigated in Lhasa,Tibet,China,between March and April,2005.Fourteen parameters were measured.These include altitude,slope,slope aspect,slope position,vegetation cover,plant type and other environmental parameters.Results show that Snow Cocks favor foraging in areas where vegetation cover was small and close to the residents’houses.Supplementary food supplied by humans has caused Snow Cocks to decrease their foraging range.Snow Cocks also favor roosting in areas with low vegetation,sparse grass,short grass,large rocks and close to houses.The Snow Cocks’activity in the study areas show a close relationship with human activities.