Morphometric study of Acipenser naccarii (Bonaparte, 1836) in fish farm individuals

The main objective of this study was to analyse differences and similarities in morphometric characteristics among specimens of the same year class of Acipenser naccarii (Bonaparte, 1836), comparing fish raised either in Italy or Spain. All specimens were Fl of captive broodstock in Italy.
Fifteen biometric variables were measured, and three derived indices were calculated, on 30 individuals of 3+ year class from Lombardy (Italy) and 90 individuals of 1+, 2+ and 3+ year class from Riofrio (Granada, Spain). A stepwise discriminate analysis (SDA) was carried out, and the results were contrasted using a non-hierarchical cluster analysis. The two groups proved to be similar, so a principal component analysis and a simple regression analysis were performed on all individuals, taking total length (Tl) as the independent variable and all the biometric variables as dependent.
The study revealed that although the Soljan index (i.e. ratio of mouth width to snout length) is related to Tl, and is a valid taxonomic characteristic, the CA index (i.e. relative position of the barbels) and FB index (i.e. ratio of snout length to width) are also valid characteristics for individuals longer than 57 cm, being independent of Tl.     

Cytochrome P-450 levels and EROD activity in the Adriatic sturgeon (Acipenser naccarii, Chondrostei) and its induction by β-Naphthoflavone

The cytochrome P-450 enzyme system was studied in juvenile Acipenser naccarii (317.6±77 g initial live weight) reared at 23°C and at a standard diet over a period of two month before using for experiments (final weight 546.3±148.8 g). While determining normal levels of cytochrome P-450 in liver tissue its induction was also studied under exposure to P-naphthoflavone (BNF; single dose at 80 mg/Kg body weight 52 hrs prior to sampling). Control fish showed total cytochrome P-450 levels in liver microsomes around 0.40±0.12 nmoles/mg proteins (n=12) while in BNF exposed fish the values increased significantly (0.55±0.11nmoles/mg proteins; n=12). Ethoxyresorufin-O-deethylase (EROD) in control fish was 0.015±0.02 nmoles/mg proteins/min (n=12); it was found to be NADPH dependent and inducible by BNF. Western Immunoblotting and enzyme-linked-immunosorbent (ELISA) analyses of liver microsomes from untreated and BNF-exposed fish, using an antibody to rat cytochrome P-450 1A1 isoform (P-450 1A1) (Nelson et al.,1996) suggested the presence of a constitutive and BNF-inducible cytochrome P-450 homologous to rat P-450 protein.
Measurement of cytochrome P-450-dependent EROD activity and P-450 1A1 expression levels in A. naccarii may be a useful parameter in monitoring environmental pollution.     

Prediction of the energy value of commercial pig feeds,according to the various energy systems used in the European Community that are based on simple analytical parameters of the feed

An attempt was made to predict the energy value of mixed pig feeds from chemical composition alone, using multiple linear regression analysis. A total of 24 commercial mixed pig feeds were collected on the Belgian market and analysed for various chemical parameters. The digestibility of the Weende nutrients was also determined.For several energy systems used in the European Community (EC), the most reliable regression is given for one to seven independent variables. It was finally found that Nettoenergie Fett (Schiemann et al., 1971), net energy growth (A. Just, 1975, personal communication), digestible energy (Schiemann et al., 1971), metabolizable energy (Just, 1975), Gesamtnährstoffe and total digestible nutrients were most accurately predicted when the following five variables were entered in the regression equation: crude protein, crude fat and the three nitrogen-free extractives (NFE) fractions: starch, invert sugars and “other NFE” (= NFE — starch — invert sugars).     

Influence of sampling conditions on blood chemistry values of Adriatic sturgeon Acipenser naccarii (Bonaparte, 1836)

Data on the blood chemistry of a chondrostean fish, the Adriatic sturgeon ( Acipenser naccarii ), are reported as measured with different sampling procedures, and as related to rearing conditions and age. Serum Cortisol, glucose, osmolality, Na⁺, Cl^-, Ca²⁺ and total protein concentrations were measured. Reference values for the blood chemistry of farmed sturgeon were measured on samples from resting undisturbed animals collected via a chronic indwelling catheter in the dorsal aorta that was implanted under anaesthesia. Following 24h recovery from catheterization, serum Cortisol, glucose and osmolality levels were 9.4 ng/ml, 58.8 mg/dl and 261.4 mOsm/kg, respectively. Furthermore, blood samples collected with the chronic indwelling catheters indicated that the surgical procedure of cannulation caused a stress response, with physiological changes that followed a pattern like that described in teleosts. Cortisol, glucose and osmolality were more sensitive to stress than the other variables measured. Sampling by cardiac puncture tended to be associated with elevated serum Cortisol levels in older, larger sturgeon, but not in young fish. Greater capture, confinement and handling stress in older, larger, sturgeon may have been responsible for this and other age-related differences in blood chemistry values measured following cardiac puncture. Within the same age class, both rearing conditions and temperature affected Cortisol, sodium and total protein concentrations significantly. Anaesthesia did not appear to reduce the degree of stress associated with cardiac puncture but altered serum ion concentrations.     

Validity of optical device lipometer and bioelectric impedance analysis for body fat assessment in men and women

The aims of this study were to validate different subcutaneous adipose tissue layers (SAT-layers) measured by lipometer for body fat percentage (BF%) assessment with dual-energy X-ray absorptiometry (DXA) and to compare the validity of lipometer and bioelectrical impedance analysis (BIA). The subjects were 21 male (18-60 years) and 19 female (23-54 years) healthy Estonian volunteers. SAT-layers were measured by lipometer using 15 standardized SAT-layers. Sum of arms, legs and trunk SAT-layers were calculated and compared with arms, legs and trunk fat percentage measured by DXA. BF% was calculated by BIA using the equations of Lukaski et al. and Chumlea et al. for both genders and the equations of Segal et al. for males and Van Loan and Mayclin for females. BF% measured by DXA was significantly higher than calculated by Lukaski et al. and Chumlea et al. in both genders. The correlation was highest between the BF% measured by DXA and using Segal et al. equation in males (r = 0.94) and Van Loan and Mayclin equation in females (r = 0.84). High relationship was observed between BF% measured by DXA and sum of 15 SAT-layers (r = 0.88 in males and r = 0.91 in females). Stepwise multiple regression analysis indicated that two selected SAT-layers explained 85.9% and 86.7% (R2 x 100) of the total variance in BF% measured by DXA in males and females, respectively: [BF% = 1.308 neck + 0.638 hip + 6.971 (males; SEE = 2.59) and BF% = 1.152 hip + 1.797 calf + 12.347 (females; SEE = 3.46)]. In conclusion, lipometer and BIA give a similar mean estimation of BF% when compared with DXA. However, there is a wide range of variance for the upper and lower limits of agreement between the methods, and the methods are not interchangeable. Lipometer seems to be superior to BIA.     

Respiratory health and air pollution: additive mixed model analyses

We conduct a reanalysis of data from the Utah Valley respiratory health/air pollution study of Pope and co-workers (Pope et al., 1991) using additive mixed models. A relatively recent statistical development (e.g. Wang, 1998; Verbyla et al., 1999; Lin and Zhang, 1999), the methods allow for smooth functional relationships, subject-specific effects and time series error structure. All three of these are apparent in the Utah Valley data.     

Adaptive branchial mechanisms in the sturgeon Acipenser naccarii during acclimation to saltwater

Variations of Na(+)/K(+)-ATPase activity and fatty-acid composition in the gills of the sturgeon Acipenser naccarii subjected to progressive acclimation to full seawater (35 ppt) were determined in relation to the hypo-osmoregulatory capacity of this species in the hyperosmotic medium. Blood samples were taken and gills arches were removed at intermediate salinity levels between 0 and 35 ppt and after 20 days at constant salinity (35 ppt). Plasma osmolality and Na(+)/K(+)-ATPase activity increased significantly with growing environmental salinity. Total saturated fatty acids (SFAs) decreased, while total polyunsaturated fatty acids (PUFAs) increased significantly with increasing salinity due mainly to changes in n-3 PUFAs (20:5n-3 and 22:6n-3). The n-3/n-6 ratio increased significantly during the acclimation process. The results show a direct relationship between salinity, increased gill Na(+)/K(+)-ATPase activity and ultrastructural changes of the gill chloride cells. Changes in the fatty-acid composition in gills of A. naccarii during progressive acclimation to full seawater suggest that variations of gill fatty acids may also have a role in osmoregulatory mechanisms.     

乳酸菌发酵液联合瑞琳他抗对HeLa细胞活性及HPV18病毒载量影响的实验

研究乳酸菌发酵液联合瑞琳他抗对宫颈癌细胞系HeLa细胞的增殖、凋亡、迁移及HPV18 DNA病毒载量的影响,为2种药物联合治疗HPV感染提供新的选择。

采用CCK8法检测不同浓度的单药、组合药对HeLa细胞增殖变化的影响,得出乳酸菌发酵液联合瑞琳他抗对HeLa细胞的半数抑制浓度（IC₅₀）;采用流式细胞术、Transwell实验和杂交捕获—化学发光法（DH3）分别检测乳酸菌发酵液联合瑞琳他抗对HeLa细胞凋亡、细胞迁移、HPV18 DNA病毒载量的影响。

通过CCK-8法检测乳酸菌发酵液IC₅₀为5.5×10⁸ CFU/mL,瑞琳他抗IC₅₀为160 mg/mL。增殖实验结果显示作用48 h后,单药组均对HeLa细胞抑制生长作用明显,且乳酸菌发酵液+瑞琳他抗组对细胞的抑制作用强于瑞琳他抗组（F=164.810,P＜0.05）;流式细胞术检测发现单药组均可诱导HeLa细胞凋亡,乳酸菌发酵液+瑞琳他抗组对细胞的凋亡作用增加且大于瑞林他抗组（F=83.823,P＜0.05）;Transwell实验发现单药组均可抑制细胞迁移,乳酸菌发酵液+瑞琳他抗组对细胞迁移的抑制作用大于瑞林他抗组（F=492.242,P＜0.05）;DH3法显示单药组均可明显下调HeLa细胞HPV18 DNA病毒载量,乳酸菌发酵液+瑞琳他抗组对细胞HPV18 DNA病毒载量的作用大于瑞林他抗组（F=284.769,P＜0.05）。

乳酸菌发酵液联合瑞琳他抗对抑制HeLa细胞增殖、诱导细胞凋亡、抑制细胞迁移和下调细胞HPV18 DNA病毒载量的作用优于瑞琳他抗,为临床治疗HPV感染提供了实验依据和借鉴。

     

1999‒2015年红塔区伤寒与副伤寒流行特征和气象变量的研究

目的 分析1999‒2015年红塔区伤寒与副伤寒（typhoid and paratyphoid fever,TPF）地方病区域流行特征和气象变量的关系,为TPF监测控制和危险因素评价提供科学依据。方法 采用描述流行病学方法和自主研发计算机软件建立中国疾病预防控制信息系统红塔区TPF病例分布与流行特征数据库,用Pearson相关分析和多元线性逐步回归分析研究TPF发病和气象变量关系。结果 1999‒2015年报告TPF病例数为8 398例,1999、2015年分别报告23、44例。1999‒2015年期间每年3~5月、6~10月、11月~次年2月分别为发病上升期（月均增长率63.8%）、高峰期（月均降低率2.0%）和下降期（月均降低率25.7%）,每年度病例数都呈现3月~10月季节性升高和11月~次年2月季节性降低;2000年8月至2010年12月每月病例数都大于8例,2000‒2002、2004‒2005、2005‒2007、2007‒2008、2008‒2010年出现五个高强度流行峰,峰期范围是12～24个月,周期范围是11～40个月;2001、2004、2006、2007、2009年五个高峰年度6~10月病例数范围分别为86～217、67～215、125～216、97～131、63～95例;1999、2000、2002、2003、2005、2008、2010、2015年八个低峰年度6月~10月病例数范围分别为1～3、1～17、32～60、30～43、46～55、43～78、22～61、2～11例。单因素分析TPF月平均发病率与月平均降雨量（r=0.825,P<0.01）、月平均气温（r=0.797,P<0.01）和月平均相对湿度（r=0.706,P<0.05）呈正相关;经多元逐步回归分析建立TPF月平均发病率（Y）与月平均降雨量（X）的拟合模型方程Y=4.563+0.051X。结论 红塔区TPF发病呈现季节性升高与降低、周期性流行、长期趋势特点;发病率与降雨量、气温、相对湿度呈正相关;传染源积累、重污染源形成、暴露人群增加驱动着流行特征与气象变量关系;相应规律、机制、政策、评估有助TPF的监测控制。     

Body size and postcranial robusticity of European Upper Paleolithic hominins

The robust diaphyses of Pleistocene hominins are said to indicate higher activity levels in these prehistoric humans than among people today. Thus, it could be argued that the prediction of body mass from fossil lower limb diaphyseal cortical area (CA) using recent human regressions might lead to erroneously high body mass estimates. This study uses three body mass prediction formulae based on the following features: reconstructed femoral 80% (subtrochanteric) CA, femoral head diameter (FH), and bi-iliac breadth and stature (BIB-St) among European Early and Late Upper Paleolithic (EUP and LUP) and recent humans from Africa and Europe. All three methods produce similar body mass estimates for all groups studied, including recent humans.Gleaning behavioral differences from these data is more difficult, as no significant differences in CA were found among the fossil and recent Europeans. It has been suggested that the EUP had less robust diaphyses than their LUP counterparts. However, here this result is only obtained when CA is size-standardized to femoral length(3) (Ruff et al., 1993, Am. J. phys. Anthrop.91, 21-53 Trinkaus et al., 1998, in Neandertals and Modern Humans in Western Asia, pp.391-404, New York: Plenum). This should not be interpreted as evidence for lower activity levels in the EUP, but rather as an artefact of standardization, for as Wolpoff (1999), Am. J. phys. Anthrop.109, 416-423 points out, these standardized variables are extremely sensitive to limb length differences, and the EUP have longer limbs than their LUP counterparts. With this in mind, these data do not support a pattern of behavioral differences between EUP and LUP humans, and therefore more sensitive measures than CA may be required to detect such differences.     

Removal of Heavy Metals from Sewage Sludge Used as Soil Fertilizer

This work has examined sewage sludge of the following heavy metal concentrations (mg/kg): Cd-3.43; Co-5.25; Cu-131; Fe-51300; Mn-177; Ni-37.5; Pb-104; Zn-3300. Metals speciation by sequential extraction according to Tessier et al. (1979), and Rudd et al. (1988), and a procedure recommended by European Community Bureau of Reference (BCR) (Ure et al., 1993; Quevauiller et al., 1996; Davidson et al., 1999), as well as analysis of chemical forms of metals, have been carried out. It has been found that only Zn concentration is higher than the value permissible for agricultural sewage sludge application (2500 mg/kg). The results obtained by Tessier et al. (1979) Tessier, A., Campbell, P. C. and Bisson, M. 1979. Sequential extraction procedure for the speciation of particulate trace metals.. Anal. Chem., 51: 844–851. [Crossref], [Web of Science ®] [Google Scholar], and BCR procedures (Ure et al., 1993; Quevauiller et al., 1996; Davidson et al., 1999) appeared to be consistent. A comparison of the sequential analysis and the analysis of chemical forms of metals indicates that the sum of metal concentrations for the exchangeable, carbonate and bound to Fe/Mn oxyhydroxides forms (found by Tessier et al., 1979, and BCR analyses (Ure et al., 1993; Quevauiller et al., 1996; Davidson, et al., 1999)) corresponds to the sum of sulfate, oxide, metallic and siliceous forms. The concentrations of the forms bound to organic matter or sulfides correspond to the sulfide form while the residue corresponds to the ferrate form. Preparative extraction of metals from the sewage sludge using sodium salt of ethylenediaminetetraacetic acid (EDTA-Na), sodium pyrophosphate (V) and ammonia water has also been investigated. As far as the examined leaching agents are concerned, EDTA-Na appeared to be the best. Single leaching with this agent results in the following metal concentrations remaining in the sludge (mg/kg): Cd-1.1; Co-2.1; Cu-105; Fe-17700; Mn-28.3; Ni-12.8; Pb-44; Zn-1200. They meet the requirements of Polish regulations concerning the use of sewage sludge as a soil fertilizer.     

Relationship between autonomic cardiovascular control,case definition,clinical symptoms,and functional disability in adolescent chronic fatigue syndrome: an exploratory study

Chronic Fatigue Syndrome (CFS) is characterized by severe impairment and multiple symptoms. Autonomic dysregulation has been demonstrated in several studies. We aimed at exploring the relationship between indices of autonomic cardiovascular control, the case definition from Centers for Disease Control and Prevention (CDC criteria), important clinical symptoms, and disability in adolescent chronic fatigue syndrome. 38 CFS patients aged 12–18 years were recruited according to a wide case definition (ie. not requiring accompanying symptoms) and subjected to head-up tilt test (HUT) and a questionnaire. The relationships between variables were explored with multiple linear regression analyses. In the final models, disability was positively associated with symptoms of cognitive impairments (p<0.001), hypersensitivity (p<0.001), fatigue (p=0.003) and age (p=0.007). Symptoms of cognitive impairments were associated with age (p=0.002), heart rate (HR) at baseline (p=0.01), and HR response during HUT (p=0.02). Hypersensitivity was associated with HR response during HUT (p=0.001), high-frequency variability of heart rate (HF-RRI) at baseline (p=0.05), and adherence to the CDC criteria (p=0.005). Fatigue was associated with gender (p=0.007) and adherence to the CDC criteria (p=0.04). In conclusion, a) The disability of CFS patients is not only related to fatigue but to other symptoms as well; b) Altered cardiovascular autonomic control is associated with certain symptoms; c) The CDC criteria are poorly associated with disability, symptoms, and indices of altered autonomic nervous activity.     

东喜马拉雅和横断山地区常绿硬叶栎类的气候封套与现代分布

Evergreen sclerophyllous oaks （the E.S. oaks, Quercus section Heterobalanus） are the dominant species of the local ecosystem in the eastern Himalaya and the Hengduan Mountains, southwest China. In this study, we document the climatic envelope of the seven E.S. oak species and examine the relationships between climate and their distribution. This was done using a principal components analysis （PCA） and multiple regression analysis （MRA） of nine climatic indices. The main climatic envelope of the E.S. oaks were： mean temperature of the warmest month （MTW）= 12.0-19.5℃, warmth index （WI） = 33.2-88.9℃ month, annual biotemperature （BT）=-6.9- -0.3 ℃, coldness index （CI）=-30.4- -10.1 ℃ month, mean temperature of the coldest month （MTC）=-3.7-3.0℃ and annual precipitation （AP）=701-897 mm at the lower limits; and MTW=8.3-16.1℃, WI=15.7-59.1℃ month, BT=3.6-8.9℃, CI=-55.4-19.3℃ month, MTC=8.3-16.1 ℃ and AP=610-811 mm at the upper limits. The climatic range of the E.S. oaks is wide and includes two climatic zones, the cool-temperature zone and the subpolar zone. The PCA and MRA results suggest that the thermal climate plays a major role and precipitation plays a secondary role in controlling the large-scale distribution of the E.S. oaks, except Quercus monimotricha. In thermal regimes, BT and/or MTW are most important for both lower and upper limits of the E.S. oaks. Furthermore, our results indicate that the upper distribution limits of the E.S. oaks are less determined by low temperatures and their duration （CI） than by other factors.     

Prognostic value of CA125 kinetics and half-life in advanced ovarian cancer

This retrospective study was undertaken in order to assess the prognostic value of prechemotherapy serum CA125 level, CA125 kinetics, and CA125 half-life compared to the ten common clinicopathological variables in patients with advanced ovarian cancer (AOC). CA125 serum levels were determined before and during induction cisplatin polychemotherapy in 222 patients. A prechemotherapy CA125 level higher than 35 U/mL was found in 134 patients. Blood samples were further obtained before each course of chemotherapy (CT). CA125 half-life values were calculated in 112 patients with CA125 levels above 60 U/mL using van der Burg's exponential regression model. The prechemotherapy CA125 level had no prognostic value for survival. However, the median survival time of patients with CA125 levels below the upper normal limit of normality after two courses of CT was 101 months compared to a median survival of 21 months in patients without CA125 normalization (p=0.0000). Half-life calculation showed a significant correlation with survival. The median survival times of patients with T1/2 <20 days and T1/2 >20 days were 101+ and 18 months, respectively (p=0.0003). In a survival analysis using the Cox proportional hazard model, independent prognostic variables for survival included therapeutic response (p<0.0001), Karnofsky index (p<0.0001), residual disease (p<0.0001), tumor grade (p=0.0002), CA125 half-life (p=0.007), and CA125 kinetics (p=0.04). As a consequence, the possibility to predict treatment response by the CA125 half-life during chemotherapy and the time needed for normalization of CA125 levels can divide patients into good and poor prognostic groups early during chemotherapy.     

An integrated genetic linkage map with 1,137 markers constructed from five F2 crosses of autoimmune disease-prone and -resistant inbred rat strains

The rat (Rattus norvegicus) is an important experimental model for many human diseases including arthritis, diabetes, and other autoimmune and chronic inflammatory diseases. The rat genetic linkage map, however, is less well developed than those of mouse and human. Integrated rat genetic linkage maps have been previously reported by Pravenec et al. (1996, Mamm. Genome 7: 117-127) (500 markers mapped in one cross), Bihoreau et al. (1997, Genome Res. 7: 434-440) (767 markers mapped in three crosses), Wei et al. (1998, Mamm. Genome 9: 1002-1007) (562 markers mapped in two crosses), Brown et al. (1998, Mamm. Genome 9: 521-530) (678 markers mapped in four crosses), and Nordquist et al. (1999, Rat Genome 5: 15-20) (330 markers mapped in two crosses). The densest linkage map combined with a radiation hybrid map, reported by Steen et al. (1999, Genome Res. 9: AP1-AP8), includes 4736 markers mapped in two crosses. Here, we present an integrated linkage map with 1137 markers. We have constructed this map by genotyping F2 progeny of five crosses: F344/NHsd x LEW/NHsd (673 markers), DA/Bkl x F344/NHsd (531 markers), BN/SsN x LEW/N (714 markers), DA/Bkl x BN/SsNHsd (194 markers), and DA/Bkl x ACI/SegHsd (245 markers). These inbred rat strains vary in susceptibility/resistance to multiple autoimmune diseases and are used extensively for many types of investigation. The integrated map includes 360 loci mapped in three or more crosses. The map contains 196 new SSLP markers developed by our group, as well as many SSLP markers developed by other groups. Two hundred forty genes are incorporated in the map. This integrated map should allow comparison of rat genetic maps from different groups and thereby facilitate genetic studies of rat autoimmune and related disease models.     

Probability models and the applicability of statistical procedures in the identification of chromosomal fragile sites

Summary. Böhm et al. (1995, Human Genetics 95 , 249–256) introduced a statistical model (named FSM–fragile site model) specifically designed for the identification of fragile sites from chromosomal breakage data. In response to claims to the contrary (Hou et al., 1999, Human Genetics 104 , 350–355; Hou et al., 2001, Biometrics 57 , 435–440), we show how the FSM model is correctly modified for application under the assumption that the probability of random breakage is proportional to chromosomal band length and how the purportedly alternative procedures proposed by Hou, Chang, and Tai (1999, 2001) are variations of the correctly modified FSM algorithm. With the exception of the test statistic employed, the procedure described by Hou et al. (1999) is shown to be functionally identical to the correctly modified FSM and the application of an incorrectly modified FSM is shown to invalidate all of the comparisons of FSM to the alternatives proposed by Hou et al. (1999, 2001). Last, we discuss the statistical implications of the methodological variations proposed by Hou et al. (2001) and emphasize the logical and statistical necessity for fragile site identifications to be based on data from single individuals.     

A comparative review of statistical methods for discovering differentially expressed genes in replicated microarray experiments

MOTIVATION: A common task in analyzing microarray data is to determine which genes are differentially expressed across two kinds of tissue samples or samples obtained under two experimental conditions. Recently several statistical methods have been proposed to accomplish this goal when there are replicated samples under each condition. However, it may not be clear how these methods compare with each other. Our main goal here is to compare three methods, the t-test, a regression modeling approach (Thomas et al., Genome Res., 11, 1227-1236, 2001) and a mixture model approach (Pan et al., http://www.biostat.umn.edu/cgi-bin/rrs?print+2001,2001a,b) with particular attention to their different modeling assumptions. RESULTS: It is pointed out that all the three methods are based on using the two-sample t-statistic or its minor variation, but they differ in how to associate a statistical significance level to the corresponding statistic, leading to possibly large difference in the resulting significance levels and the numbers of genes detected. In particular, we give an explicit formula for the test statistic used in the regression approach. Using the leukemia data of Golub et al. (Science, 285, 531-537, 1999), we illustrate these points. We also briefly compare the results with those of several other methods, including the empirical Bayesian method of Efron et al. (J. Am. Stat. Assoc., to appear, 2001) and the Significance Analysis of Microarray (SAM) method of Tusher et al. (PROC: Natl Acad. Sci. USA, 98, 5116-5121, 2001).     

Swimming alters responses to hypoxia in the Adriatic sturgeon Acipenser naccarii

When the Adriatic sturgeon Acipenser naccarii was exposed to progressive hypoxia under static conditions, it exhibited a linear decline in O₂ uptake, behaving as an 'oxyconformer'. When, however, it was allowed to swim at a low sustained speed, it could regulate O₂ uptake down to a mean ± s . e . critical ( P _crit) of 4·9 ± 0·5 kPa ( n = 6). At moderate levels of hypoxia, static fish exhibited significant reductions in arterial blood O₂ content, and increases in plasma lactate, which were not observed in swimming animals.