Modeling Harvest Intensity of Sooty Shearwater Chicks by Rakiura Māori in New Zealand

Abstract: Cultural evidence suggests that sooty shearwater (Puffinus griseus) chicks have been harvested by Rakiura Māori on islands in southern New Zealand since prehistoric times. Concerns exist that modern harvests may be impacting sooty shearwater abundance. We modeled human-related and ecological determinants of harvest (total no. of individuals harvested) of sooty shearwater chicks on 11 islands and examined the relationship between shearwater abundance and harvesting rates (chicks/hr) and harvester behavior throughout the harvesting season. Models best explaining variation in harvest between harvesting areas (manu), for both the early and late parts of the harvesting season, included harvester-days (included in all models with change in deviance information criteria [ΔDIC], ΔDIC < 8.36 and ΔDIC < 11.5, for the early and late periods, respectively). Other harvest determinants included shearwater density, size of the manu, and number of people helping harvesters (all included in the top 5 models within ΔDIC = 2.25 for the late period). Areas harvested by several families under a common-property harvesting system had higher harvest intensity for their size (24% points higher, 95% credible interval 11–36%) than those managed as an exclusive resource for one family. The slowest harvesters spent more time harvesting but on average only harvested 36% (95% credible interval 15–65%) and 34% (95% credible interval 12–63%) of the harvest taken by the fastest harvesters during the early and late periods, respectively. Our results highlight the possibility of elevated harvest intensity as the population of harvesters increases. However, our models suggested that a corresponding reduction in harvesting rate at low prey densities during the most productive period could potentially regulate harvest intensity. Future research will integrate these results into prospective shearwater demographic models to assess the utility of a range of harvesting strategies in ensuring harvest sustainability.     

Seasonal Abundance and Species Richness of Birds in Common Reed Habitats in Lake Erie

Abstract: Common reed (Phragmites australis) forms dense stands with deep layers of residual organic matter that negatively affects plant diversity and possibly habitat use by wetland birds. We sought to determine whether seasonal relative abundance and species richness of birds varied among 3 habitat types in Great Lakes coastal wetland complexes recently invaded by common reed. We used fixed-distance point counts to determine species relative abundances and species richness in edge and interior locales within common reed, cattail (Typha spp.), and meadow marsh habitats of various sizes during 2 summers (2001 and 2002) and 1 autumn (2001) at Long Point, Lake Erie, Ontario, Canada. We found that total relative abundance and species richness of birds were greater in common reed habitat compared to cattail or meadow marsh habitats. However, we also found that relative abundance of marsh-nesting birds was greater in meadow marsh habitat than in cattail and common reed during summer. Lastly, we found that, irrespective of habitat type, habitat edges had higher total relative abundance and species richness of birds than did habitat interiors. Our results show that common reed provides suitable habitat for a diversity of landbirds during summer and autumn but only limited habitat for many marsh-nesting birds during summer. Based on these results, we recommend restoration of meadow marsh habitat through reduction of common reed in Great Lakes wetlands where providing habitat for breeding marsh-nesting birds is an objective. Managers also might consider reducing the size of nonnative common reed stands to increase edge effect and use by birds, possibly including wetland birds.     

三个小麦春化基因的时空表达特性分析(英文)

为明确小麦春化基因的时空表达特性,以中国春和洛旱2号小麦品种为试验材料,利用半定量RT-PCR技术,分析了3个春化基因VERNALIZATION1(VRN1)、VRN2和VRN3的时空表达特性。结果表明,VRN1在中国春的三叶期叶片和根、灌浆期的茎秆和旗叶、花药、胚珠和发育的种子中均有不同程度的表达。在开花前,表达水平呈上升趋势,而花后呈降低的趋势,在干种子和萌发种子的胚芽中没有检测到表达;在洛旱2号中,除了在三叶期的叶片和根中没有检测到表达外,VRN1的表达特性与中国春有相同的趋势。VRN2只在三叶期的叶片和萌发种子的胚芽中表达,在其他检测的组织中没有表达;VRN3的表达与VRN1的时空表达特性相似,但在根中未检测到表达。这一结果为进一步分析普通小麦品种春化发育的分子调控机理提供了重要信息。     

荞麦属植物淀粉酶和甲酸脱氢酶同功酶研究(英文)

以聚丙烯酰胺凝胶电泳方法研究了荞麦属植物8个种42个收集系干种子和发芽种子的淀粉酶和甲酸脱氢酶同功酶。结果表明,荞麦淀粉酶在于种子中缺乏活性,但是在发芽种子中活性很强。在供试材料的发芽种子中共发现23个淀粉酶谱带,其中甜荞和苦荞分别有10条和8条。不同荞麦种间淀粉酶谱带差异很大,但是同种内不同收集系间差异较小。谱带聚类分析表明大野荞和毛野荞分别与甜荞和苦荞较近缘,支持它们分别为甜荞和苦荞祖先种的假说。在干种子和发芽种子中,发现所有荞麦种类均只有1条位置一致的甲酸脱氢酶谱带,暗示该酶在进化中具有高度稳定性。     

Intestinal epithelium in Anarhichas lupus L., with emphasis on cell renewal

Histomorphological studies on the dynamics of intestinal epithelium in larvae, juveniles and adult stages of common wolffish Anarhichas lupus showed that the major structural development took place during the first 8 weeks after hatching ( c . 320 day degrees). This development preceeded a period of increase in relative growth. The mucosa of the proximal and distal intestine gradually developed from simple primary mucosal folds into a complex structure of primary and secondary folds with regularly distributed crypts. Cell proliferation, based on the observations of the presence of immature cells, mitotic figures and proliferating cell nuclear antigen reacting cells, was limited to the crypts after 8 weeks of age. The observation of bands of epithelial cells showing apoptotic and necrotic changes, suggested the existence of extrusion zones, where effete cells were eliminated by both shedding and phagocytosis. In the proximal intestine of adult common wolffish, increasing amounts of lipids were observed from the upper part of the crypts to the surface epithelium, probably reflecting an increased maturation of epithelial cells.     

Quantification of the elevated rate of domain rearrangements in metazoa

Most eukaryotic proteins consist of multiple domains created through gene fusions or internal duplications. The most frequent change of a domain architecture (DA) is insertion or deletion of a domain at the N or C terminus. Still, the mechanisms underlying the evolution of multidomain proteins are not very well studied.Here, we have studied the evolution of multidomain architectures (MDA), guided by evolutionary information in the form of a phylogenetic tree. Our results show that Pfam domain families and MDAs have been created with comparable rates (0.1-1 per million years (My)). The major changes in DA evolution have occurred in the process of multicellularization and within the metazoan lineage. In contrast, creation of domains seems to have been frequent already in the early evolution. Furthermore, most of the architectures have been created from older domains or architectures, whereas novel domains are mainly found in single-domain proteins. However, a particular group of exon-bordering domains may have contributed to the rapid evolution of novel multidomain proteins in metazoan organisms. Finally, MDAs have evolved predominantly through insertions of domains, whereas domain deletions are less common.In conclusion, the rate of creation of multidomain proteins has accelerated in the metazoan lineage, which may partly be explained by the frequent insertion of exon-bordering domains into new architectures. However, our results indicate that other factors have contributed as well.     

Growth and energy budget of F2'all-fish' growth hormone gene transgenic common carp

The growth and energy budget for F₂‘all‐fish’ growth hormone gene transgenic common carp Cyprinus carpio of two body sizes were investigated at 29·2° C for 21 days. Specific growth rate, feed intake, feed efficiency, digestibility coefficients of dry matter and protein, gross energy intake (I_E), and the proportion of I_E utilized for heat production (H_E) were significantly higher in the transgenics than in the controls. The proportion of I_E directed to waste products [faecal energy (F_E) and excretory energy loss (Z_E+U_E) where Z_E is through the gills and U_E through the kidney], and the proportion of metabolizable energy (M_E) for recovered energy (R_E) were significantly lower in the transgenics than in the controls. The average energy budget equation of transgenic fish was as follows: 100 I_E= 19·3 F_E+ 6·0 (Z_E+U_E) + 45·2 H_E+ 29·5 R_E or 100 M_E= 60·5 H_E+ 39·5 R_E. The average energy budget equation of the controls was: 100 I_E= 25·2 F_E+ 7·4 (Z_E+U_E) + 35·5 H_E+ 31·9 R_E or 100 M_E= 52·7 H_E+ 47·3 R_E. These findings indicate that the high growth rate of ‘all‐fish’ transgenic common carp relative to their non‐transgenic counterparts was due to their increased feed intake, reduced lose of waste productions and improved feed efficiency. The benefit of the increased energy intake by transgenic fish, however, was diminished by their increased metabolism.     

Management-Induced Reproductive Failure and Breeding Dispersal in Double-Crested Cormorants on Lake Champlain

ABSTRACT We studied breeding dispersal of double-crested cormorants (Phalacrocorax auritus) associated with management practices that suppressed their reproduction on Lake Champlain in the northeastern United States. We implemented an experiment on one colony by spraying corn oil on cormorant eggs in portions of the colony and leaving other portions untreated. Gulls (Larus spp.) consumed cormorant eggs during the oiling process, but we reduced and then eliminated predation levels after the first year of the study. We used mark-recapture techniques within the experimental framework to measure rates of breeding dispersal for cormorants from the experimental colony and an unmanaged colony in Lake Champlain. Egg oiling increased the movement rate to the unmanaged colony by 3% during the year with no egg predation by gulls. When gulls depredated cormorant eggs at high rates during egg oiling, movement to the unmanaged colony increased by 20%. When cormorants are managed to reduce population sizes, methods that limit dispersal away from the managed colony may be most effective. Such methods would mitigate effects to nontarget populations and allow for a greater portion of the metapopulation to be managed.