Southern oscillation and the northern australian prawn catch

Associations are established between the southern oscillation index (SOI) and penaeid prawn catches within the northern Australian prawn fishery. Analysis involved calculation of correlations between Gulf of Carpentaria banana prawn andtiger prawn catches and Troup’s SOI. Significant positive correlations are observed between catch size and SOI for specific months from pre-wet to post-wet seasons. For banana prawns, the results indirectly confirm some earlier observations of increased catches in conjunction with high rainfall during the onset of monsoon periods, but also indicate an association with late rains. However, the relationship with tiger prawns appears to be in the opposite direction, showing negative correlations with SOI for particular months. Some hypotheses are suggested to explain these results in terms of environmental effects on spawning populations, and comment is made on the potential for forecasting catch sizes. Received: 17 August 1998 / Accepted: 23 June 1999     

Great Lakes coastal wetland habitat use by seven turtle species: influences of wetland type, vegetation, and abiotic conditions

Great Lakes coastal wetlands are important habitats for turtles but few studies have looked at factors driving community structure in these systems. We evaluated the effects of wetland type, vegetation, and abiotic conditions on turtle communities for 56 wetlands in Lakes Huron, Michigan, and Superior with data collected during the summers of 2000–2008. Overall, 1,366 turtles representing seven species were captured using fyke nets. For the majority of species, catches were highest in drowned river mouth wetlands In addition, turtles tended to be more abundant in water lilies, submersed aquatic vegetation, and cattails compared to bulrush. We also found positive correlations between catches of four of the species as well as total turtle catch and turtle species richness with a human disturbance gradient. These correlations suggest that turtles may be able to utilize coastal wetland areas that are inhospitable to fish because of hypoxic conditions. Our results show the importance Great Lakes coastal wetlands to turtles, and stress the need for managers to take into account turtle populations when preparing conservation and restoration strategies.     

Airborne inoculum dynamics of Polystigma amygdalinum and progression of almond red leaf blotch disease in Catalonia,NE Spain

The dynamics of airborne ascospores and disease progress of red leaf blotch (RLB) of almond, caused by Polystigma amygdalinum, and their correlations with weather variables were studied from 2019 to 2021 in two almond orchards located in Lleida, NE Spain. Airborne ascospores were detected and quantified by real-time qPCR using species-specific primers for P. amygdalinum. Ascospores were detected mainly from April to June, with a high variability between the yearly cumulative concentrations. Positive significant correlations were found between the weekly proportion of airborne ascospores and the number of wet and mild days—either combined or separated— accumulated rainfall, number of rainy days, accumulated low temperatures on wet days, and mean and maximum relative humidity. In contrast, several thermal variables (maximum temperature, VPD, and number of warm days) were negatively correlated with ascospore catches. Positive significant correlations were found between the cumulative proportion of ascospores and RLB incidence and severity. Weekly variations in RLB incidence and severity showed significant positive correlations with the number of warm days while negative with the number of mild days. Severity was also positively correlated with several thermal variables (mean, maximum, and minimum temperature, and VPD), and negatively correlated with the number of cold days and wet and mild days. Stronger correlations were generally found with ascospore catches or disease progress when using concurrent weekly weather data. Gompertz, monomolecular, and logistic growth models were evaluated to describe RLB disease progress.     

稻麦轮作系统冬小麦农田耕作措施对氧化亚氮排放的影响

2008—2011年,采用静态箱-气相色谱法对长江下游稻麦轮作系统冬小麦农田N2O排放进行了为期3a的田间原位观测,研究不同耕作措施(免耕、旋耕和翻耕)对冬小麦生长季N2O排放的影响。结果表明:不同耕作措施下冬小麦农田N2O排放高峰出现在施用基肥后的1个月内以及施用孕穗肥后的4月中旬至小麦成熟期,其余时间N2O排放通量均较小。年度和耕作措施对冬小麦农田N2O季节排放总量均有极显著影响(P<0.01),不同处理N2O季节排放总量表现为免耕>翻耕>旋耕,2008—2011年3年平均分别为2.50 kg/hm2、2.05 kg/hm2和1.66 kg/hm2,免耕比翻耕增加N2O排放22.0%(P<0.05),旋耕比翻耕减排19.0%(P<0.05)。冬小麦生长期内施用孕穗肥后1个月内N2O排放通量与农田土壤充水孔隙率(WFPS)及10 cm地温呈显著(P<0.05)或极显著(P<0.01)正相关,2009—2010年施用基肥后1个月内N2O排放通量与WFPS呈显著负相关(P<0.05)。结果说明旋耕是减少长江下游稻麦轮作系统冬小麦农田N2O排放的最佳耕作措施。     

Correlations in fossil extinction and origination rates through geological time

Recent analyses have suggested that extinction and origination rates exhibit long-range correlations, implying that the fossil record may be controlled by self-organized criticality or other scale-free internal dynamics of the biosphere. Here we directly test for correlations in the fossil record by calculating the autocorrelation of extinction [corrected] and origination rates through time. Our results show that extinction rates are uncorrelated beyond the average duration of a stratigraphic interval. Thus, they lack the long-range correlations predicted by the self-organized criticality hypothesis. In contrast, origination rates show strong autocorrelations due to long-term trends. After detrending, origination rates generally show weak positive correlations at lags of 5-10 million years (Myr) and weak negative correlations at lags of 10-30 Myr, consistent with aperiodic oscillations around their long-term trends. We hypothesize that origination rates are more correlated than extinction rates because originations of new taxa create new ecological niches and new evolutionary pathways for reaching them, thus creating conditions that favour further diversification.     

Long-term changes of aphid vectors of Barley yellow dwarf viruses in north-eastern Italy (Friuli-Venezia Giulia)

Migrations of aphid vectors of Barley yellow dwarf viruses (BYDV) were monitored using a Rothamsted Insect Survey suction trap in Friuli-Venezia Giulia (north-eastern Italy). Catches from 1983 to 2002 were studied for trends, correlations of total catches of each year with those of previous years, correlations between the autumn and the spring + summer catches of the same year and between spring + summer catches of one year with catches of the previous autumn. Infectivity of autumn alates was studied using biological tests, and infectivity indexes were calculated for all vector species and for Rhopalosiphum padi alone. Colonisation of barley and proportion of infected plants were checked in a field close to the suction trap from 1992 to 2002 and related to trap catches. Catches were also correlated to acreage dedicated to cereal and fodder crops in the region. During the 20 years, 15 BYDV vector species were caught in the trap, but only five species were found consistently colonising barley plants during autumn. R. padi was the most numerous species in catches, while Sitobion avenae was the predominant colonising species in the barley field. Relatively to R. padi , S. avenae colonies were about six times more numerous than expected from catches. The yearly abundance of catches of most species did not change significantly during the 20 years, with a few exceptions, significantly correlated to changes in the acreage dedicated to cereal and fodder crops. There was a significant decrease of the autumn catches of both R. padi and the total of BYDV vectors.     

Do nutrient-competition models predict nutrient availabilities in limnetic ecosystems?

Recent theory on resource competition, predicated on the importance of hypothesized trade-offs between minimum requirements for nutrient resources, predicts that there should be negative correlations between the supply rate of major limiting nutrients and the availability of at least some secondary nutrients and/or among the availabilities of different limiting nutrients. However, an analysis of four data sets from large-scale surveys of lakes shows mostly positive correlations among the availabilities and supplies of nutrients. In contrast, a fifth data set, obtained in an area of high acidification, does show several important negative correlations that are consistent with the nutrient competition models. Further analyses suggest two possible explanations for the preponderance of positive correlation. Negative correlations between nutrients and light indicate that an important trade-off among species regulating phytoplankton may involve low light requirements versus low nutrient requirements. The existence of negative correlations in nutrient availabilities in acidic lakes (where herbivory appears less important than in buffered lakes) also suggests that another important trade-off may involve an ability to minimize loss rates (especially due to grazing) versus an overall ability to exploit nutrient resources. Received: 23 February 1996 / Accepted: 30 September 1996     

The statistical inevitability of stability-diversity relationships in community ecology

In this article, we explain an often overlooked process that may significantly contribute to positive correlations between measures of species diversity and community stability. Empirical studies showing positive stability-diversity relationships have, for the most part, used a single class of stability (or, more accurately, instability) measures: the temporal variation in aggregate community properties such as biomass or productivity. We show that for these measures, stability will essentially always rise with species diversity because of the statistical averaging of the fluctuations in species' abundances. This simple probabilistic process will operate in the absence of any strong species interactions, although its strength is driven by the relative abundances of species, as well as by the existence of positive or negative correlations in the fluctuations of species. To explore the possible importance of this effect in real communities, we fit a simple simulation model to Tilman's grassland community. Our results indicate that statistical averaging might play a substantial role in explaining stability-diversity correlations for this and other systems. Models of statistical averaging can serve as a useful baseline for predictions of community stability, to which the influences of both negative and positive species interactions may then be added and tested.     

Neutrophil Gelatinase-Associated Lipocalin (NGAL) Predicts Response to Neoadjuvant Chemotherapy and Clinical Outcome in Primary Human Breast Cancer

In our previous work we showed that NGAL, a protein involved in the regulation of proliferation and differentiation, is overexpressed in human breast cancer (BC) and predicts poor prognosis. In neoadjuvant chemotherapy (NACT) pathological complete response (pCR) is a predictor for outcome. The aim of this study was to evaluate NGAL as a predictor of response to NACT and to validate NGAL as a prognostic factor for clinical outcome in patients with primary BC. Immunohistochemistry was performed on tissue microarrays from 652 core biopsies from BC patients, who underwent NACT in the GeparTrio trial. NGAL expression and intensity was evaluated separately. NGAL was detected in 42.2% of the breast carcinomas in the cytoplasm. NGAL expression correlated with negative hormone receptor (HR) status, but not with other baseline parameters. NGAL expression did not correlate with pCR in the full population, however, NGAL expression and staining intensity were significantly associated with higher pCR rates in patients with positive HR status. In addition, strong NGAL expression correlated with higher pCR rates in node negative patients, patients with histological grade 1 or 2 tumors and a tumor size <40 mm. In univariate survival analysis, positive NGAL expression and strong staining intensity correlated with decreased disease-free survival (DFS) in the entire cohort and different subgroups, including HR positive patients. Similar correlations were found for intense staining and decreased overall survival (OS). In multivariate analysis, NGAL expression remained an independent prognostic factor for DFS. The results show that in low-risk subgroups, NGAL was found to be a predictive marker for pCR after NACT. Furthermore, NGAL could be validated as an independent prognostic factor for decreased DFS in primary human BC.     

From stochastic environments to life histories and back

Environmental stochasticity is known to play an important role in life-history evolution, but most general theory assumes a constant environment. In this paper, we examine life-history evolution in a variable environment, by decomposing average individual fitness (measured by the long-run stochastic growth rate) into contributions from average vital rates and their temporal variation. We examine how generation time, demographic dispersion (measured by the dispersion of reproductive events across the lifespan), demographic resilience (measured by damping time), within-year variances in vital rates, within-year correlations between vital rates and between-year correlations in vital rates combine to determine average individual fitness of stylized life histories. In a fluctuating environment, we show that there is often a range of cohort generation times at which the fitness is at a maximum. Thus, we expect ‘optimal’ phenotypes in fluctuating environments to differ from optimal phenotypes in constant environments. We show that stochastic growth rates are strongly affected by demographic dispersion, even when deterministic growth rates are not, and that demographic dispersion also determines the response of life-history-specific average fitness to within- and between-year correlations. Serial correlations can have a strong effect on fitness, and, depending on the structure of the life history, may act to increase or decrease fitness. The approach we outline takes a useful first step in developing general life-history theory for non-constant environments.     

A preliminary survey of the artisanal fishery on coral reefs of the Tulear Region (southwest Madagascar)

Fish catches from the coral reefs of the Tulear region (southwest Madagascar), are analyzed based on fish landings. This region of the island consists of two barrier reefs, two coral banks, three lagoon reefs and a fringing reef. The total reef area studied was 190 km². Of the whole fishing area, the reef flat was the most frequently used by fishermen. Line catches per unit efort (CPUE) were stable throughout the eight month sampling period (6 to 8 kg/trip to sea), whereas gillnet and seine catches showed differences between the cold period and the warm period. These results appear to be representative of the artisanal fishery catches in the southwest Indian Ocean. Annual fish yield was estimated at 12 t km^-2 yr^-1. Comparable yields have been recorded in certain regions of the Indo-Pacific, that have similar ratios of coral reef area to adjacent shallows and similar fishing practices. Reef species (Lethrinidae, Siganidae) dominated the catches. At present, coastal waters of the Tulear region are heavily fished, and the fishermen report a progressive decrease in the average size of fish caught over the last 15 years. Management measures are suggested, based on preliminary findings.     

Varietal differences in potassium uptake by barley

Potassium influx isotherms were obtained for 10 cultivars of barley using plants which had been grown with or without potassium (high K⁺ and low K⁺ plants, respectively), and the cultivars ranked with respect to K_m or V_max values for influx with a view to using these rankings as a predictive measure of long term performance under conditions of potassium-limited growth. Analyses of these rankings revealed significant differences between cultivars. Net uptake rates for low K⁺ plants, determined over a 24-hour period, confirmed the differences between upper (Herta) and lower (Conquest) ranked cultivars, and established similar differences in the rates of translocation to the shoot. Efflux analyses showed no differences in potassium efflux from the cytoplasm or from the vacuole for these cultivars. Growth rate studies under different conditions of potassium limitation indicated, with some exceptions, strong positive correlations between ranks accorded cultivars on the basis of influx kinetics and those based upon growth rates.     

Fecal antibody levels as a noninvasive method for measuring immunity to gastrointestinal nematodes in ecological studies

Among‐individual variation in antibody‐associated immunity to gastrointestinal nematode parasites (GIN) is known be associated with life‐history traits and vital rates in wild vertebrate systems. To date, measurement of levels of antibodies against GIN antigens in natural populations has exclusively been based on invasive blood sampling techniques. Previous work in laboratory rodents and ruminant livestock suggests that antibody measures from feces may provide a viable noninvasive approach. We measured total and anti‐GIN antibodies of different isotypes (immunoglobulin (Ig) G, IgA and IgE) from paired samples of plasma and feces from free‐living Soay sheep of different ages and sexes. We tested the correlations among these measures as well as their associations with body mass and Strongyle nematode fecal egg counts (FEC). Significant positive correlations were present among plasma and fecal anti‐GIN antibody levels for IgG and IgA. Generally, correlations between total antibody levels in plasma and feces were weaker and not significant. No significant relationships were found between any antibody measures and body mass; however, fecal anti‐GIN antibody levels were significantly negatively correlated with FEC. Our data clearly demonstrate the feasibility of measuring anti‐GIN antibodies from fecal samples collected in natural populations. Although associations of fecal antibody levels with their plasma counterparts and FEC were relatively weak, the presence of significant correlations in the predicted direction in a relatively small and heterogeneous sample suggests fecal antibody measures could be a useful, noninvasive addition to current eco‐immunological studies.     

Modeling environmental, spatial, temporal, and operational effects on blue shark by-catches in the Mediterranean long-line fishery

A study was conducted from 1998 to 2001 on blue shark ( Prionace glauca ) by-catch of the Italian and Greek surface-drifting swordfish long-line fisheries in the Mediterranean Sea. The focus was on examining whether catches are related to some environmental, spatial, temporal or operational parameters and to what extent, applying generalized linear model (GLM) approaches. Analyses indicated that most appropriate for the dataset was the Delta-lognormal model, which is a binomial error distribution for the probability of a non-zero catch and lognormal error for positive catch rates. Spatial and temporal factors were the most influential regarding blue shark distribution and abundance, with a considerable interaction between them; the modeled environmental factors were of minor importance. Spatial distribution revealed a strong longitudinal gradient whereby blue shark occurrences increased in an east to west direction, whereas catches by latitude were higher in southern- and northern-most regions. Blue sharks were more frequently encountered in autumn and in distant open waters; however, the likelihood of making a larger catch peaked in late spring–early summer and in the vicinity of land. Catch rates differed significantly depending on the fishing gear configuration. Deeper settings (>20 m), more resilient lines and use of fish attractants increased the probability of P. glauca capture.     

The response of isoprene emission rate and photosynthetic rate to photon flux and nitrogen supply in aspen and white oak trees

Isoprene is the primary biogenic hydrocarbon emitted from temperate deciduous forest ecosystems. The effects of varying photon flux density (PFD) and nitrogen growth regimes on rates of isoprene emission and net photosynthesis in potted aspen and white oak trees are reported. In both aspen and oak trees, whether rates were expressed on a leaf area or dry mass basis, (1) growth at higher PFD resulted in significantly higher rates of isoprene emission, than growth at lower PFD, (2) there is a significant positive relationship between isoprene emission rate and leaf nitrogen concentration in both sun and shade trees, and (3) there is a significant positive correlation between isoprene emission rate and photosynthetic rate in both sun and shade trees. The greater capacity for isoprene emission in sun leaves was due to both higher leaf mass per unit area and differences in the biochemical and/or physiological properties that influence isoprene emission. Positive correlations between isoprene emission rate and leaf nitrogen concentration support the existence of mechanisms that link leaf nitrogen status to isoprene synthase activity. Positive correlations between isoprene emission rate and photosynthesis rate support previous hypotheses that isoprene emission plays a role in protecting photosynthetic mechanisms during stress.     

How reliable are light traps in estimating biting rates of adult Anopheles gambiae s.l. (Diptera: Culicidae) in the presence of treated bed nets?

The sampling efficiency of light trap catches relative to human bait catches in estimating biting rates of the mosquito Anopheles gambiae Giles was investigated in two types of community in southern Sierra Leone: (i) where most of the inhabitants slept under treated bed nets; and (ii) where most of the inhabitants slept without bed nets. The number of female A. gambiae mosquitoes caught in these communities by light trap was strongly correlated (r > or = 0.72) with those from corresponding human biting catches performed either on the same or adjacent nights. It was found that the relative sampling efficiency of light traps varied slightly but significantly with mosquito abundance in villages with treated bed nets, but not in those without them. Nevertheless, the relationship between relative sampling efficiency and mosquito abundance did not differ significantly between the two types of village. Overall, there was insufficient evidence to show that the presence of treated nets altered the relative efficiency of light traps and any bias was only slight, and unlikely to be of any practical importance. Hence, it was concluded that light traps can be used as a surrogate for human bait catches in estimating biting rates of A. gambiae mosquitoes in the two communities.     

小兴安岭森林沼泽甲烷排放及其影响因子

 利用静态箱-气相色谱法, 对小兴安岭5种森林沼泽生长季甲烷(CH₄)排放通量进行研究, 并探讨了温度、地下水位和植被等主要环境因子对CH₄排放的影响。结果表明: 毛赤杨(Alnus sibirica)沼泽、落叶松(Larix gmelinii)-藓类(Moss)沼泽和落叶松-泥炭藓(Sphagnum spp.)沼泽的CH₄排放有明显的季节变化规律, 而白桦(Betula platyphylla)沼泽和落叶松-苔草(Carex schmidtii)沼泽CH₄通量的季节变化相对较小。落叶松-泥炭藓沼泽有爆发式CH₄通量现象出现, 对生长季CH₄排放通量影响较大。在生长季内落叶松-泥炭藓沼泽、毛赤杨沼泽和白桦沼泽为大气CH₄的源, 而落叶松-苔草沼泽和落叶松-藓类沼泽为大气CH₄的汇, 生长季CH₄的平均排放通量分别为(56.08 ± 200.38)、(15.34 ± 14.89)、(0.64 ± 0.88)、(–0.88 ± 1.76)和(–0.94 ± 3.00) mg·m^–2·d^–1。除落叶松-泥炭藓沼泽外, 不同森林沼泽类型间CH₄排放通量随地下水位升高而增大; 地下水位在–34.5 ~ –30.8 cm之间可能存在CH₄源与汇的临界点, 季节平均地下水位低于这一位置的森林沼泽为大气CH₄的汇。温度对森林沼泽CH₄通量的影响比较复杂, 二者间可能为正或负的显著(p＜0.05)或非显著(p＞0.05)相关关系。CH₄通量与乔木地上生物量有较强的负相关性, 这有可能成为小兴安岭森林沼泽CH₄通量的最佳预测因子。     

HERITABLE VARIATION IN ETHANOL TOLERANCE AND ITS ASSOCIATION WITH BIOCHEMICAL TRAITS IN DROSOPHILA MELANOGASTER

To help elucidate mechanisms of larval ethanol tolerance seven isochromosomal lines of Drosophila melanogaster with different second chromosomes were fed a growth-limiting concentration of ethanol (4.5% v/v) and examined for associations between growth traits and biochemical characteristics that had previously been implicated in the determination of tolerance variation. Repeated measures of survival and development time over four generations verified the inherited nature of these traits. Significant variation among the lines were evident for flux from ethanol into lipid, for activity levels of alcohol dehydrogenase and glycerol-3-phosphate oxidase (GPO), and for levels of long chain and unsaturated fatty acids. A high degree of positive association occurred among the variables. A partial correlation analysis controlling for performance of the lines on ethanol-free medium revealed a strong association between the degree of long chain fatty acid content and line survival when ethanol was fed. The correlation between GPO activity and survival in an ethanol environment appeared to depend on the association of GPO activity with long chain fatty acid content. The positive correlations of flux from ethanol into lipid with many of the other variables suggested that the ADH pathway influenced the level of ethanol tolerance. These associations are all consistent with the hypothesis that the lipid content of body tissues, especially the levels of long chain and unsaturated fatty acids in cell membranes, may have an important influence on both spatial and interspecific variation in the ethanol tolerance of larvae.     

The consequences of using different measures of mean abundance to characterize the abundance–occupancy relationship

Aim To investigate the influence of choice of the measure of mean abundance on the abundance–occupancy relationship, and to examine the implications for identifying causal mechanisms. Innovation Simulations were performed to generate stochastic abundance–occupancy data sets covering a wide range of scenarios representative of empirical abundance–occupancy data. Two common measures of mean abundance were used: local mean abundance (mean abundance calculated using only data from occupied sites) and global mean abundance (mean abundance calculated using all sites or samples). I found that the choice of mean abundance measure had a strong effect on the correlation between abundance and occupancy. Local mean abundance was associated with a high proportion of negative correlations (mean percentage of negative correlations across 24 simulations = 44.39), while global mean abundance was strongly associated with positive correlations (mean percentage of negative correlations across 24 simulations = 0.02). Main conclusions The choice of abundance measure influences the correlation between abundance and occupancy. Negative correlations between local mean abundance and occupancy are an inherent and unavoidable consequence of using this measure of abundance. Efforts to identify causal mechanisms that give rise to the abundance–occupancy relationship have attempted to explain occasional negative correlations when the expectation was for positive correlations. This study shows that negative correlations arise from the choice of mean abundance measure and that this artefact confounds efforts to identify ecological causal mechanisms.     

Comparison of occupational exposure methods relevant to musculoskeletal disorders: Worker-workstation interaction in an office environment

Work related musculoskeletal disorders have been associated with office work yet exposure quantification is challenging and not measured consistently. Our objective was to examine associations within and across exposure measurements guided by a conceptual model of three measurement locations: external to the body, at the interface, and internal to the body. Forty-one office workers (71% female), mean age 41 years (SD=9.6), mean height 168cm (SD=10.3), and mean weight 74kg (SD=19), were recruited from a large urban newspaper. Four methods of quantifying mechanical exposure were used linked to locations: equipment dimensions (external), relative fit and postures (interface), and EMG (internal). We explored: (1) a within-location analysis of relationships among methods; and (2) a cross-location analysis of relationships among methods. Exposure method comparisons showed mostly weak correlations among equipment variables, moderate correlations among posture variables, and strong or moderate correlations among EMG variables. For the majority of pair-wise comparisons between exposure measures across locations, the correlations were weak or moderate. Comparisons of relative fit revealed some differences in dimensions, postures, and EMG measures. Few strong associations between various exposure measures were found, although worker-reported relative fit holds promise. Future work might link exposure methods (specific measures) with locations for particular purposes.