Organochlorines and mercury in the eggs of British Peregrines Falco peregrinus

The levels of various contaminants were measured in 550 addled and deserted Peregrine Falco peregrinus eggs obtained in Britain during 1963-86. In this period the population was recovering from a low level imposed by organochlorine pesticides. Over the whole period, HEOD levels declined in eggs from both inland and coastal regions, while DDE levels declined in eggs from inland regions. At the same time, shell-indices improved. PCB levels increased in eggs from inland regions. At any one time, levels of DDE and HEOD in eggs decreased and shell-indices increased from south to north within Britain. These gradients fitted with the extent of agricultural land (= pesticide use) and with the extent of Peregrine population decline (both greatest in the south). No south-north trend was apparent in levels of PCBs derived from industrial sources. In some regions eggs from coastal sites were more contaminated than eggs from inland sites, especially with PCBs and mercury. Significant relationships were found between brood sizes and DDE levels, between brood sizes and shell-indices, and between shell-indices and DDE levels. This implied that DDE influenced shell thickness and breeding success. Some evidence was obtained that mercury reduced brood sizes, but no evidence that HEOD and PCB (at the levels found) did so. Overall, DDE and mercury levels together accounted for 17% of the variance in brood sizes during 1963-86. On a regional basis, DDE had no obvious effect on mean productivity when the geometric mean DDE level in collected eggs was less than 3 p.p.m., and when mean shell-index was no more than 8% less than normal. At higher DDE levels, and lower shell-indices, productivity declined markedly. Recovery of regional populations was associated with geometric mean HEOD levels in eggs no greater than 0–7 p.p.m., DDE levels no greater than 15 p.p.m., shell indices no more than about 15–20% below normal, and a mean breeding success exceeding 0–6 young per territorial pair.     

Lateral asymmetry of kidney weights in different populations of wild mice

Weights of right and left kidneys were compared in different populations of wild mice. Samples were taken from Great Britain, Pacific islands and Sub-Antarctica. The different population samples were further subdivided according to sex and age as estimated by tooth category (i.e., degree of development or wear of upper molars). The mean weights of right kidneys exceeded those on the left in all 28 Subsamples but the data suggested mat this difference decreased with age. The evidence further suggested that the asymmetry between the two kidneys was greater in populations of small mice from the Pacific islands than in those of large mice from Britain and Sub-Antarctica. On the basis of published data on rats and guinea pigs the question is raised whether interspecific differences in kidney asymmetry may be explicable by differences in the sizes of the kidneys in different species.     

SHORT REVIEWS

Book reviewed in this article:
Redoutk's Fairest Flowers. Martyn Rix and William T. Stearn. 3 12 pp., 144 colour plates
The Mushrooms and Toadstools of Britain and North-western Europe. Marcel Bon, with illustrations by John Wilkinson
The Plant-Book. D.J. Mabberley. 706 pp., Cambridge University Press. 1987     

The diversity of Hymenoptera in the tropics with special reference to Parasitica in Sulawesi

Abstract. 1. The results of a recent faunistic survey of the Hymenoptera of northern Sulawesi, Indonesia, are compared with the known British fauna.
2. All families of Hymenoptera are probably more species rich in Sulawesi than in Britain, with the possible exception of Symphyta and gall-forming Cynipidae.
3. The diversities of the samples obtained from Sulawesi are compared with those published from previous studies on the relationship between latitude, altitude and the diversity of parasitic Hymenoptera in tropical and temperate regions.
4. Despite its possibly greater species richness, the Ichneumonidae as a whole was no more diverse in the Sulawesi samples than in samples taken in temperate areas, including Britain.
5. The diversity of Parasitica as a whole appears to have been greater in the Sulawesi samples than those from either Britain or Michigan but lower than those from Costa Rica.
6. Parasitica as a whole was probably not more diverse inside the forest than at its edge, but the Aculeata was more diverse at its edge.
7. Both Parasitica and Aculeata were less diverse at 1765 m than at 220 m altitude.     

Spring arrival patterns of the Cuckoo Cuculus canorus,Nightingale Luscinia megarhynchos and Spotted Flycatcher Musciapa striata in Britain

Data on the arrival dates of Cuckoo, Nightingale and Spotted Flycatcher published in the Royal Meteorological Society phenological reports are presented. From these records, contour maps showing the pattern of progression through Britain were produced for each species. Of the three species, the Cuckoo arrived earliest and progressed the slowest from south to north; it entered Britain by the southeast. The Nightingale arrived later than the Cuckoo and progressed along a southeast to northwest axis. The Spotted Flycatcher was the last to arrive, but progressed with the greatest speed from south to north. Arrival dates of all three species were influenced by the temperature in southern Europe in the month preceding arrival in Britain and by the difference between these temperatures in southern Europe and those a month later in France or Britain. The diminishing population levels of Nightingale may have had a masking effect on its arrival dates. Although mean arrival dates for the three species were strongly influenced by temperature, long-term trend effects should be interpreted with caution as other factors also influence mean arrival dates.     

TRB3基因敲除减轻糖尿病小鼠中骨骼肌萎缩和纤维化的研究

摘要 目的：探讨TRB3基因敲除对糖尿病小鼠中骨骼肌萎缩和纤维化的影响。方法：选择30只TRB3敲除（TRB3-/-）小鼠和30只C57/BL6J小鼠，随机分为4组，包括TRB3基因敲除糖尿病模型组（A组）、TRB3基因敲除正常对照组（B组）、普通对照组（C组）和糖尿病模型组（D组）。正常对照组小鼠喂养标准大鼠饲料，糖尿病模型小鼠使用腹腔注射小剂量链脲佐菌素的方法建立糖尿病小鼠模型。进行前肢握力测试、悬栅试验、肌肉功能试验，同时测定骨微结构各指标水平、抗I型胶原蛋白和抗III型胶原蛋白水平、萎缩基因MuRF1和Atrogin-1水平。结果：A组、B组、D组小鼠前肢握力显著低于C组，其中D组小鼠前肢握力最低（P<0.05）；A组、B组、D组小鼠悬栅试验倒挂时间显著低于C组，其中D组小鼠悬栅试验倒挂时间最短（P<0.05）；A组、B组、D组小鼠肌肉功能CSA值显著低于C组，其中D组小鼠肌肉功能CSA值最低（P<0.05）；A组、B组、D组小鼠骨微结构指标BMD、BV/TV、Tb.N、Tb.Th值显著小于C组，其中D组数值最低（P<0.05）；而Tb.Sp和SMI值显著大于C组，其中D组数值最高（P<0.05）；A组、B组、D组小鼠抗I型胶原蛋白和抗III型胶原蛋白水平显著高于C组，其中D组抗I型胶原蛋白和抗III型胶原蛋白水平最高（P<0.05）；A组、B组、D组小鼠萎缩基因MuRF1和Atrogin-1水平显著高于C组，其中D组萎缩基因MuRF1和Atrogin-1水平最高（P<0.05）。结论：TRB3基因敲除可显著减轻糖尿病小鼠中骨骼肌萎缩和纤维化，增加骨强度。     

Differential effects of 1,25-dihydroxyvitamin D3 upon intestinal vitamin D3-dependent calbindin (a 28,000-dalton calcium binding protein) and its mRNA in D-replete and D-deficient chickens

The effect of vitamin D3 status upon the responsiveness of chick intestinal epithelium to exogenous 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] was studied. Intestinal calbindin [A recent consensus decision was made to redesignate the vitamin D-dependent calcium binding protein as "calbindin-D28K" (R.H. Wasserman (1985) in Vitamin D: Chemical, Biochemical, and Clinical Update (Norman, A.W., Schaefer, K., Grigoleit, H.-G., and Herrath, D.V., Eds.), pp. 321-322, de Gruyter, Berlin/New York).] protein and intestinal calbindin mRNA were quantitated in birds which had been raised on a vitamin D3-deplete (-D) or on a vitamin D3-replete (+D) diet. 1,25(OH)2D3 stimulated intestinal calbindin mRNA levels in -D chickens in a proportional dose-dependent manner, when measured at both 12 and 48 h after administration of the hormone. A first increase was observed with 1,25(OH)2D3 concentrations between 0.065 and 0.65 nmol. The maximal stimulation achieved by 1,25(OH)2D3 (6.5-18 nmol) in -D tissue was approximately 10-fold over the calbindin mRNA levels present in vehicle-treated birds. The increase of calbindin mRNA in -D birds was associated with a similar dose-dependent increase in calbindin protein in 1,25(OH)2D3-treated -D birds after 12 or 48 h. In +D intestine, while exogenous 1,25(OH)2D3 also increased calbindin mRNA levels in a dose-dependent fashion, the maximal stimulation observed after 5 h (1.2- to 2-fold) was clearly less than that observed in -D intestine. In contrast to -D birds, intestinal calbindin levels in +D birds were decreased by administration of exogenous 1,25(OH)2D3. Administration of 32.5 to 65 nmol 1,25(OH)2D3 resulted in an approximately 1.8-fold repression compared to vehicle-treated birds. This differential responsiveness between +D and -D intestines with respect to 1,25(OH)2D3 was not explained either by differences in the uptake in the chromatin fractions of these tissues or by metabolism of radiolabeled 1,25(OH)2D3. Dietary withdrawal of vitamin D3 led to a gradual decline in ambient intestinal calbindin levels, while intestinal sensitivity to 1,25(OH)2D3 was restored. These findings suggest that vitamin D3 status regulates intestinal responsiveness to the seco-steroid 1,25(OH)2D3.     

Fibrinogen-Fibrin Degradation Product Levels in Different Types of Intravascular Haemolysis

To examine the possibility that intravascular haemolysis may lead to intravascular coagulation we have compared the degree of fibrin deposition, as measured by levels of serum fibrinogen-fibrin degradation products (F.D.P.), in two different types of intravascular haemolysis associated with red cell fragmentation. F.D.P. levels in 56 patients with intravascular haemolysis secondary to prosthetic heart valves were compared with those in 18 patients who had microangiopathic haemolytic anaemia (M.H.A.) associated with malignant hypertension or renal disease. F.D.P. levels were raised in almost all the patients with M.H.A., and this group had significantly higher levels than any of the valve replacement groups. In contrast, in the prosthetic valve patients F.D.P. levels were usually normal and bore no relation to the degree of haemolysis. It is suggested that in the absence of other precipitating factors intravascular haemolysis will not initiate intravascular coagulation. In M.H.A., while the intravascular haemolysis appears to be a consequence of an underlying intravascular coagulation, it is likely that persistence of the coagulation disturbance is related more to factors such as small vessel damage than to the release of any thromboplastic substances from fragmented red cells.     

特发性矮小症患儿治疗前后血清IGF-1、IGFBP-3、25（OH）D、皮质醇水平变化及其与体格发育和骨龄的相关性分析

摘要 目的：探究特发性矮小症（ISS）患儿治疗前后血清胰岛素样生长因子1（IGF-1）、胰岛素样生长因子结合蛋白3（IGFBP-3）、25羟维生素D[25（OH）D]、皮质醇水平变化及其与体格发育和骨龄的相关性。方法：选取安徽省儿童医院于2017年7月～2021年3月收治的88例ISS患儿作为研究组。另选取同期体检健康儿童88例作为对照组。比较两组血清IGF-1、IGFBP-3、25（OH）D及皮质醇水平。比较ISS患儿治疗前后血清IGF-1、IGFBP-3、25（OH）D及皮质醇水平,体格指标以及骨龄指标。通过Pearson相关性分析ISS患儿血清IGF-1、IGFBP-3、25（OH）D及皮质醇水平与体格指标、骨龄指标的相关性。结果：研究组患儿血清IGF-1、IGFBP-3、25（OH）D水平均低于对照组,而皮质醇水平高于对照组（均P＜0.05）。ISS患儿治疗后血清IGF-1、IGFBP-3、25（OH）D水平均高于治疗前,而皮质醇水平低于治疗前（均P＜0.05）。ISS患儿治疗后身高、体重、骨龄年龄差（BAD）、骨龄指数（BAI）以及体质指数（BMI）均高于治疗前（均P＜0.05）。经Pearson相关性分析发现：ISS患儿血清IGF-1、IGFBP-3、25（OH）D水平与身高、体重、BAD、BAI以及BMI均呈正相关;皮质醇与身高、体重、BAD、BAI以及BMI均呈负相关（均P＜0.05）。结论：ISS患儿血清IGF-1、IGFBP-3、25（OH）D水平异常降低,皮质醇水平升高,且上述四项指标均和身高、体重、BAD以及BAI有关。     

New Stereoacuity Test Using a 3-Dimensional Display System in Children

The previously developed 3-dimensional (3D) display stereoacuity tests were validated only at distance. We developed a new stereoacuity test using a 3D display that works both at near and distance and evaluated its validity in children with and without strabismus. Sixty children (age range, 6 to 18 years) with variable ranges of stereoacuity were included. Side-by-side randot images of 4 different simple objects (star, circle, rectangle, and triangle) with a wide range of crossed horizontal disparities (3000 to 20 arcsec) were randomly displayed on a 3D monitor with MATLAB (Matworks, Inc., Natick, MA, USA) and were presented to subjects wearing shutter glasses at 0.5 m and 3 m. The 3D image was located in front of (conventional) or behind (proposed) the background image on the 3D monitor. The results with the new 3D stereotest (conventional and proposed) were compared with those of the near and distance Randot stereotests. At near, the Bland-Altman plots of the conventional and proposed 3D stereotest did not show significant difference, both of which were poorer than the Randot test. At distance, the results of the proposed 3D stereotest were similar to the Randot test, but the conventional 3D stereotest results were better than those of the other two tests. The results of the proposed 3D stereotest and Randot stereotest were identical in 83.3% at near and 88.3% at distance. More than 95% of subjects showed concordance within 2 grades between the 2 tests at both near and distance. In conclusion, the newly proposed 3D stereotest shows good concordance with the Randot stereotests in children with and without strabismus.     

Influence of vitamin D receptor genotype on bone mineral density in postmenopausal women: a twin study in Britain.

OBJECTIVES--To investigate the possible association between vitamin D receptor genotype and bone mineral density in a large group of postmenopausal twins. DESIGN--Cross sectional twin study. SETTING--Twin population based in Britain. SUBJECTS--95 dizygotic (non-identical) pairs of twins and 87 monozygotic (identical) pairs of twins aged 50-69 years, postmenopausal, and free of diseases affecting bone, recruited from a national register of twins and with a media campaign. MAIN OUTCOME MEASURES--Bone mineral density measured at the hip, lumbar spine, forearm, and for the whole body by dual energy x ray absorptiometry in relation to differences in the vitamin D receptor genotype. RESULTS--At all sites the values of bone density among dizygotic twins were more similar in those of the same vitamin D receptor genotype than in those of differing genotype, and the values in the former were closer to the correlations seen in monozygotic twins. Women with the genotype that made them at risk of osteoporotic fracture had an adjusted bone mineral density that was significantly lower by SD 0.5 to 0.6 at the hip, lumbar spine, and for the whole body. The results could not be explained by differences in age, weight, years since menopause, or use of hormone replacement therapy. CONCLUSIONS--The findings that in postmenopausal women in Britain bone density-particularly at the hip and spine-is genetically linked and specifically associated with the vitamin D receptor genotypes should lead to novel approaches to the prevention and treatment of osteoporosis.     

Estrogen influences dolichyl phosphate distribution among glycolipid pools in mouse uteri

The steroid hormone 17 beta-estradiol dramatically induces uterine N-linked glycoprotein assembly [Dutt, A., Tang, J.-P., Welply, J. K., & Carson, D. D. (1986) Endocrinology (Baltimore) 118, 661-673]. To determine the role that dolichyl phosphate availability plays in this induction, we studied the effects of estrogen priming on the content of dolichyl phosphate and the distribution of dolichyl phosphate among various glycolipids in uteri. Dolichol-linked saccharides were metabolically labeled to equilibrium with either [3H]glucosamine or [3H]mannose and extracted from primary explants of uterine tissue. The amount of dolichol-linked saccharide was calculated from the specific radioactivity determined for the corresponding sugar nucleotides extracted from the tissues. The major dolichol-linked saccharides identified were mannosylphosphoryldolichol (MPD), oligosaccharylpyrophosphoryldolichol (OSL), and N,N'-diacetylchitobiosylpyrophosphoryldolichol (CBL). Estrogen increased the levels of MPD and OSL 4-fold; however, CBL levels did not change. After 3 days of treatment, the levels of these glycolipids were very similar to those in uteri from pregnant mice. Remarkably, MPD constituted 90-95% of dolichol-linked saccharides detected under all conditions. The tissue contents of total dolichyl phosphate and alkali-labile dolichyl phosphate, presumably MPD, were estimated by liquid chromatography. The levels of alkali-labile dolichyl phosphate determined in this way were in good agreement with the values estimated for MPD by metabolic labeling; moreover, alkali-labile dolichyl phosphate constituted 50-98% of the total dolichyl phosphate pool. The variations in MPD content depended upon the steroid hormone influence, most notably that of estrogen.(ABSTRACT TRUNCATED AT 250 WORDS)     

Vitamin D state of Asians living in Pakistan.

Asians living in Pakistan have serum 25-hydroxycholecalciferol concentrations which are well within the normal range and significantly higher than in Asians resident in Britain. Clearly, Asians can maintain an adequate vitamin D state given an abundant supply of ultraviolet light, and the expression of vitamin D deficiency is an environmental and not a genetically determined characteristic. The risk of an Asian developing vitamin D deficiency increases after migration to Britain. The most efficient way to treat this is by supplementation with vitamin D.     

肥胖合并高脂血症患者血清食欲素A、25-羟维生素D3、瘦素水平与胰岛素抵抗、脂代谢紊乱和肥胖评价指标的相关性分析

摘要 目的：探讨肥胖合并高脂血症患者血清食欲素A（orexin A）、25-羟维生素D3[25-(OH)D3]、瘦素（Leptin）水平与胰岛素抵抗、脂代谢紊乱和肥胖评价指标的相关性。方法：选择2019年2月至2021年12月中国医科大学附属第四医院收治的105例肥胖合并高脂血症患者为研究组,另取同期在中国医科大学附属第四医院健康体检的73例志愿者为对照组。检测并对比两组血清orexin A、25-(OH)D3、Leptin、胰岛素抵抗相关指标、脂代谢指标及肥胖评价指标水平的差异。采用Pearson相关性分析血清orexin A、25-(OH)D3、Leptin水平与胰岛素抵抗相关指标、脂代谢指标及肥胖评价指标的相关性。结果：研究组血清orexin A、25-(OH)D3水平低于对照组,而Leptin水平高于对照组（P＜0.05）。研究组空腹血糖（FPG）、空腹胰岛素（FINS）、胰岛素抵抗指数（HOMA-IR）水平均高于对照组（P＜0.05）。研究组总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白胆固醇（LDL-C）水平高于对照组,而高密度脂蛋白胆固醇（HDL-C）水平低于对照组（P＜0.05）。研究组体质量指数（BMI）、腰臀比、腰高比均高于对照组（P＜0.05）。肥胖合并高脂血症患者的血清orexin A、25-(OH)D3水平与FPG、FINS、HOMA-IR、TC、TG、LDL-C水平、BMI、腰臀比、腰高比均呈负相关,与HDL-C水平呈正相关（P＜0.05）;Leptin水平与FPG、FINS、HOMA-IR、TC、TG、LDL-C水平、BMI、腰臀比、腰高比均呈正相关,与HDL-C水平呈负相关（P＜0.05）。结论：肥胖合并高脂血症患者血清orexin A、25-(OH)D3水平降低,Leptin水平升高,且与胰岛素抵抗、脂代谢紊乱及肥胖指标升高有关。     

The red blood cell Esterase D polymorphism in Europe and Asia

Summary Several regional series from Britain and 3 Asian series were typed for the Esterase D polymorphism. It was found that haemolysates up to 5 years old could be reliably typed when prepared from washed anticoagulated red blood cells. Lysates prepared from blood clots do not retain Esterase D activity quite as well. The Manx population has higher Esterase D 2 gene frequencies than neighbouring populations. A Nepalese population exhibits the highest Esterase D 2 gene frequency so far recorded. The other series presented supplement or confirm results already published.     

MHR、UACR、25（OH）D3与2型糖尿病患者下肢动脉病变的关系研究

摘要 目的：探讨单核细胞/高密度脂蛋白胆固醇（HDL-C）比值（MHR）、尿白蛋白/尿肌酐比值（UACR）、25-羟维生素D3[25（OH）D3]与2型糖尿病（T2DM）患者下肢动脉病变（LEAD）的关系。方法：选择2017年1月至2021年6月延边大学附属医院西区医院收治的195例T2DM患者,根据LEAD检查结果将患者分为LEAD组（104例）和非LEAD组（91例）。检测单核细胞、HDL-C、尿白蛋白、尿肌酐、25（OH）D3水平,计算MHR、UACR。比较两组MHR、UACR、25（OH）D3差异,单因素及多因素Logistic回归分析影响T2DM患者发生LEAD的危险因素,受试者工作特征（ROC）曲线分析MHR、UACR、25（OH）D3预测T2DM患者发生LEAD的价值。结果：LEAD组年龄、体质量指数大于非LEAD组,吸烟史、高血压比例高于非LEAD组,T2DM病程长于非LEAD组,总胆固醇（TC）、低密度脂蛋白胆固醇（LDL-C）、空腹血糖（FPG）高于非LEAD组,高密度脂蛋白胆固醇（HDL-C）低于非LEAD组（均P＜0.05）。LEAD组MHR、UACR高于非LEAD组,25（OH）D3水平低于非LEAD组（P＜0.05）。多因素Logistic回归分析显示,年龄过大、T2DM病程过长、高MHR、高UACR是T2DM患者发生LEAD的危险因素（P＜0.05）,高25（OH）D3是其保护因素（P＜0.05）。MHR、UACR、25（OH）D3预测T2DM患者发生LEAD的曲线下面积分别为0.728、0.755、0.759,联合三项指标后预测T2DM患者发生LEAD的曲线下面积为0.888,高于单独指标预测。结论：MHR、UACR增高和25（OH）D3水平降低与T2DM患者发生LEAD有关,联合三项指标在预测T2DM患者并发LEAD方面具有较高的价值。     

Effect of fetal sex on maternal and fetal human chorionic gonadotropin levels and comparison of their levels in paired umbilical arteries and veins

There were discordant results regarding the effect of fetal sex on human chorionic gonadotropin (hCG) concentrations in maternal or fetal circulation and regarding whether the levels in umbilical arteries are equal to those in umbilical veins. Totally, 188 singleton pregnancies at 36 to 42 weeks of gestation without any obstetrical or medical complication were studied. The hCG levels were measured by radioimmunoassay specific for hCG using Sb3 antibody raised against beta-subunit of hCG. The maternal ages and parities between those who gave birth to a male or a female baby were not different statistically. The birth weights between male and female babies were also not different. The serum hCG levels had a wide range in maternal circulation (200-75,200 mIU/ml) and their distribution was positively skewed. The mean value (geometric mean, G.M.) in maternal circulation for those who carried a female fetus (11,500 mIU/ml) was significantly higher than that for those carrying a male fetus (6,470 mIU/ml) (P less than 0.001, Student's t-test). The hCG concentrations in umbilical veins of female fetuses were also higher than in those of male fetuses (G.M., 26.8 vs 19.5 mIU/ml, P less than 0.01, Student's t-test). Umbilical arterial hCG levels (G.M., 10.05 mIU/ml) were statistically not different from umbilical venous levels (G.M., 10.92 mIU/ml) (paired t-test).(ABSTRACT TRUNCATED AT 250 WORDS)     

Two- and three-dimensional proton NMR studies of apo-neocarzinostatin.

Neocarzinostatin (NCS) is an antitumor protein from Streptomyces carzinostaticus that is identical in apo-protein sequence with mitomalcin (MMC) from Streptomyces malayensis. We describe the use of apo-NCS as a model system for applying combined two- and three-dimensional (2D and 3D) proton NMR spectroscopy to the structure determination of proteins (Mr greater than 10K) without isotope labeling. Strategies aimed at accurately assigning overlapped 2D cross-peaks by using semiautomated combined 2D and 3D data analysis are developed. Using this approach, we have assigned 99% of the protons, including those of the side chains, and identified about 1270 intra- and interresidue proton-proton interactions (fixed distances are not included) in apo-NCS. Comparing our results with those reported recently on 2D NMR studies of apo-NCS [Adjadj, E., Mispelter, J., Quiniou, E., Dimicoli, J.-L., Favadon, V., & Lhoste, J.-M. (1990) Eur. J. Biochem. 190, 263-271; Remerowski M. L., Glaser, S. J., Sieker, L., Samy, T. S. A., & Drobny, G. P. (1990) Biochemistry 29, 8401-8409] demonstrated advantages of proton 3D NMR spectroscopy in protein spectral assignments. We are able to obtain more complete proton resonance and secondary structural assignments and find several misassignments in the earlier report. Strategies utilized in this work should be useful for developing automation procedures for spectral assignments.     

Genetic differentiation of a European caddisfly: past and present gene flow among fragmented larval habitats

We describe the genetic structure of a freshwater insect species and interpret it in terms of present-day population dynamics and possible postglacial colonization history. The sampling regime represented a large area of the species range in northwest Europe, particularly focusing on Britain, a region relatively neglected in molecular population genetic studies. Plectrocnemia conspersa generally showed low levels of genetic variation across the sampled populations (Nei's D = 0.0138) and subdivision was unrelated to the pattern of the drainage network. However, the results do suggest that populations across the region are not at equilibrium and that British populations still show effects of the recolonization of the species following the last glacial maximum. Levels of genetic diversity were lower in Britain than in mainland Europe. Two-dimensional scaling showed genetic differentiation between major regions and the pattern of genetic diversity indicates a more recent origin of populations in the north and west of the area compared with the south and east. We argue that, despite the highly fragmented larval habitat, dispersal over tens of kilometres is frequent. Over longer distances, however, P. conspersa does still show evidence of founder effects and postglacial range expansion into Britain.