Relaxed predation risk reduces but does not eliminate sociality in birds

Disentangling the relative contribution of predation avoidance and increased foraging efficiency in the evolution of sociality in animals has proven difficult given that the two types of benefits often operate concurrently. I identified different types of refuges from predation in birds related to morphological and ecological traits, providing an opportunity to examine concomitant changes in sociality over evolutionary times. Results of a matched-species comparative analysis indicated a reduction in the size of foraging or non-foraging groups but not complete disappearance under negligible predation risk. The results suggest that while predation avoidance is an important component in the evolution of sociality in birds, it is most probably not acting alone but rather in conjunction with other benefits such as increased foraging efficiency.     

伊米果蝇种组（Drosophila immigrans species group）H2a-H2b和Cyt b分子系统发育关系（简报）

伊米果蝇种组(Drosophila immigrans speciesgroup)是果蝇科(Drosophilidae)、果蝇属(Drosophi-la)、果蝇亚属(Drosophila)中数量最多的一个类群,主要分布于东洋区。在分类学上该种组分为nasuta、immigrans、hypocausta、quadrilineata和curviceps五个种亚组(species subgroup)[1],东洋区果蝇区系中伊米果蝇种组中包括94个种,其中有45个种分布在中国[2]。而且curviceps种亚组是1992年新建立的中国特有果蝇类群[3]。迄今,对伊米果蝇种组分子系统关系的报道还很少,有些物种的归属仍存在争议。伊米果蝇种组还有些问题需要探讨[4]。组蛋白基因…     

Classification of ecological types of the Chinese yak

To investigate the genetic resources and to clarify the classification status of the Chinese yak, the Maiwa yak, Jiulong yak, Datong yak, and Tianzhu White yak were intensively studied using microsatellite DNA, RAPD (random amplified polymorphic DNA), and AFLP (Amplified Fragment Length Polymorphism) DNA markers on the basis of the previous study work of the authors' on chromosomes and blood protein polymorphisms of the Chinese yak. The overall results showed that: (1) the genetic distance based on allele frequencies at the microsatellite loci between the Maiwa yak and Jiulong yak was the largest (1.506), and as expected, the two populations of the Maiwa yak had the smallest genetic distance (1.062). The four yak breeds were clustered into two groups: the first group comprised the Jiulong yak, and the second group comprised the remaining three breeds; (2) the genetic distance between the Datong yak and Tianzhu White yak was the smallest (0.0336), whereas the genetic distance between the Jiulong yak and Maiwa yak was the largest (0.0414) based on the data from the RAPD and RFLP analyses. The four yak breeds were again clustered into two groups with the Datong yak and Tianzhu White yak grouped together first, followed by the Maiwa yak; (3) analyses of the chromosomes and blood protein polymorphisms showed a similar pattern of relationship among the breeds. Therefore, it was concluded that the Chinese yak could be considered to be of two types with the Jiulong yak and Maiwa yak as their representatives, respectively. This conclusion was in accordance with the classification proposed later by professor Cai L and his colleagues, according to which the Chinese yak was classified into two types, the ‘Qinghai-Tibetan Plateau yak’ and the ‘Hengduan Mountain Alpine yak’, although this conclusion differed from the other classifications. Considering the geographic distribution, ecological factors, history and development of the Chinese yak, it was believed that this classification is reasonable.     

The perceived effectiveness of continuing care and group support in the long-term self-help treatment of obesity

Objective : Obesity is increasingly considered a chronic disease requiring continuing care, but professional long‐term treatment for most patients is not available. This study examined treatment recipients’ perception of the effectiveness of different components of a group self‐help, continuing‐care treatment program for obesity. Research Methods and Procedures : Members (n = 120) and volunteer leaders (n = 66) of a self‐help, continuing‐care treatment program of previously demonstrated effectiveness (mean treatment duration, 40.6 months; mean weight lost, 14.1 kg) rated how helpful and effective they found the various therapeutic strategies used by this program. The strategies examined were continuing care, group support, behavior therapy, motivational enhancement strategies involving positive reinforcement, and motivational enhancement strategies involving punishment. Results : The single most highly valued aspect of treatment was the provision of continuing care, followed by group support. Greater success at achieving one's goal weight was associated with perceptions of greater effectiveness of the program's strategies overall (r = 0.219, p < 0.005), of continuing care (r = 0.225, p < 0.005), and of positive reinforcement strategies (r = 0.223, p < 0.01). Participants who had successfully attained their goal weight perceived behavior therapy strategies as more effective than did participants who had not reached their goal weight [t (170) = 2.93, p < 0.005]. Discussion : The high ratings given to continuing care and group support strategies indicate the acceptability of supportive self‐help treatment for obesity administered over the long term. The findings suggest that continuing care and group support should be made available to participants in the self‐help treatment of obesity.     

The Saurida undosquamis group (Aulopiformes: Synodontidae), with description of a new species from southern Japan

Four lizardfishes of Saurida (family Synodontidae), S. undosquamis, S. umeyoshii sp. nov., S. macrolepis, and S. longimanus, are described. All are recognized here as the Saurida undosquamis group, characterized by having dark dots on the upper margin of the caudal fin, pectoral fin exceeding origin to pelvic fin, anterior rays of dorsal fin neither elongate nor filamentous, predorsal length greater than distance between dorsal-fin and adipose-fin origins, 46–55 pored lateral-line scales, and vomer with 0–8 teeth. Saurida undosquamis, from northern West India and West Pacific, excluding East Asia, differs from others in having lateral-line scales ridged on the caudal peduncle, conspicuously concave posterior margin of the pectoral fin, 51–55 pored lateral-line scales, and 50–53 vertebrae. Saurida umeyoshii sp. nov., from southern Japan and the East China Sea, is defined by three rows of indistinct dark blotches on, above, and below the lateral line, distribution of scale pockets with melanophores on their posterior part extending over the entire abdominal region from the lateral line in specimens over ca. 130 mm SL, lateral-line scales not ridged on caudal peduncle, 49–52 pored lateral-line scales, and 48–50 vertebrae. Saurida macrolepis, from the Indo-West Pacific, is characterized by 46–49 pored lateral-line scales and 45–48 vertebrae. Saurida longimanus, from northern West India, northwest Australia, and southern Indonesia, differs from the others in having a long pectoral fin extending past the origin of the dorsal fin. Some geographic variations are found in S. macrolepis. Saurida grandisquamis is confirmed as a junior synonym of S. undosquamis, based on examination of the type specimens. A key to species in the S. undosquamis group is included.     

BSE risk assessments in the UK: a risk tradeoff?

Risk assessments for bovine spongiform encephalopathy (BSE) should be based on the group risk and not the median individual risk. The group risk is calculated from the arithmetic mean risk, which in the case of dorsal root ganglia, is a factor of 50-fold higher than the median. For environmental routes, the arithmetic mean exposure is sufficient for risk assessment, while for food-borne routes failure to accommodate the variation in exposures to individuals across the UK population could overestimate the group risk considerably. Ignoring prion destruction by cooking could overestimate the food-borne risks still further. The recent estimate for the arithmetic mean cow-to-man species barrier of 4000 does not take into accounts either of these factors and thus may be too high. Until evidence for a threshold dose is demonstrated, public health scientists should avoid assessing safety on the basis of a 'minimum infective dose'. The incubation period observed in cattle-feeding studies, when completed, would continue to increase with decreasing dose below the ID50if there is a threshold or co-operative effect. The question is raised of whether fears over BSE in drinking water contributed to the spread of foot-and-mouth disease across the UK in 2001; a risk tradeoff.     

Detection of a Specific Transposon in Erysiphe necator from Grapevines in France

The biotrophic fungus, Erysiphe necator the causal agent of the grape powdery mildew, has two genetic groups A and B in European and Australian vineyards. A strain of group A was used to isolate a DNA sequence that exhibits high sequence homology to RNaseH of a non‐LTR (long tandem repeat) retrotransposon of Glomerella cingulata. PCR primers were designed and tested for their specificity to genetic group A of E. necator. This molecular tool is more efficient and sensitive than nested PCR based on polymorphism in the CYP₅₁ and β‐tubulin genes.     

Karyology and karyotype analysis of diploid freshwater planarian populations of the Dugesia gonocephala group (Platyhelminthes,Tricladida) found in Sardinia

Karyology and karyotype analysis were carried out on freshwater planarian populations of the Dugesia gonocephala group. The strains studied were all diploid with chromosomic number 2n = 16; n = 8. They came from 12 sites mainly localized on the west of the island of Sardinia. Three karyotypes indicated with the letters A, B and C were found in which eight homomorphic pairs of chromosomes were easily identified. In karyotype A all chromosomes are metacentric. Ten populations of the twelve examined showed this karyotype which appears to be the most common. In karyotype B the seventh pair of chromosomes is submetacentric. This karyotype is quite common having been previously found in another eight Sardinian localities. Karyotype C differs from the others in having submetacentric third and seventh pairs of the chromosome complement. It was found in only one locality. The differences observed between these three karyotypes could be interpreted either as sign of differentiation at species level, or as an intraspecific variation due to chromosome mutations (pericentric inversions). This revised version was published online in July 2006 with corrections to the Cover Date.     

Assignment of cytosine N3 resonances in nucleic acids via intrabase three-bond coupling to amino protons

Coherences were observed between ¹⁵N3 of cytosine and its trans amino proton (H42) using a modified gradient-based heteronuclear single quantum coherence (HSQC) pulse sequence optimized for three-bond proton-nitrogen couplings. The method is demonstrated with a 22-nucleotide RNA fragment of the P5abc region of a group I intron uniformly labeled with ¹⁵N. Use of intraresidue ¹⁵ N3-amino proton couplings to assign cytosine ¹⁵ N3 signals complements the recently proposed J_NN HNN COSY [Dingley, A.J. and Grzesiek, S. (1998) J. Am. Chem. Soc., 120, 8293–8297] method of identifying hydrogen-bonded base pairs in RNA.     

Social organization of the golden brown mouse lemur (Microcebus ravelobensis)

Our study provides the first data on the social organization of the golden brown mouse lemur, a nocturnal primate discovered in northwestern Madagascar in 1994. The study was carried out in two 6-month field periods during the dry season, covering time before and during the mating season. The spatial and temporal distributions of the sexes in the population were investigated by mark/recapture and radiotelemetry. Focal observations and the determination of sleeping associations provided further insights into the sociality of this solitary forager. High intra- and intersexual home-range overlaps occurred throughout the study. In general, individuals of both sexes had spatial access to more than one conspecific of the same and the opposite sex. We found no indication for spatial monopolization of females by certain males. These results suggest a dispersed multimale/multifemale system with a promiscuous mating pattern. Individuals showed temporal stability in their home range locations and interacted regularly with conspecifics. Five sleeping groups were identified during the study period: one female group and four mixed-sex groups. Even though sleeping sites were changed frequently, sleeping-group compositions remained stable over time. Thermoregulatory constraints are the most likely explanation for sleeping-group composition with members of both sexes in this species. Mixed-sex sleeping groups can be described as the basic social unit within this dispersed multimale/multifemale society.