Natural Life History Research Articles

Antirealism/realism of Wittgenstein's language-game idea

Wittgenstein’s language-game idea allews/us te find out both, antirealistic and realistic tendencies, what is required te abanden classification an realistic and antirealistic (constructivistic, instrumentalistic) approaches in semantics and methodology of science/that originated in discussions on the philosophy of mathematics. Using some relevant commentators of Wittgenstein’s works (Dummett, Baker, Hintikka, Kiripke. C. Wright etc.) a broader notion of realism will be obtained using the following questions: A. human reality: natural history or forms of life (behaviour, practice, training, customs and institutions — language-games and correct use), B. new objectivity: community, agreement (criterion - following rules), C. the new nuance in the nation of truth: justification, verification (proof as an method of verification). The results of the analysis will be the impontant for a new criterion of realism such as: the general notion of reality, objectivity as intersubjectivity and the nuances in the notion of truth.With the new criterion we have the following map of realism: 1. F-rege-Tarski-Carnap truth-conditional realism, 2. Frege-Wittgenstein justification/verificatdonist realism, 3. Frege-Wittgenstein-Hintikka verificationist/falsificationist realism.The possibility of Frege-Wittgenstein-Dummett neoveificationist realism is open to further research.

Natural history and courtship behavior in Tengella perfuga Dahl, 1901 (Araneae: Zoropsidae)

Tengella perfuga Dahl, 1901 is a Nicaraguan cribellate zoropsid spider found in high altitude remnant cloud forest habitats bordering coffee plantations. Since its description in 1901, and its rediscovery in 2012, almost nothing is known of its natural history, life history, courtship or web spinning behavior. Observations were made in the field, as well as in the lab. Mature female T. perfuga occurred in funnel webs with several knockdown lines comprised of cribellate silk, and that were typically placed between buttress roots of strangler figs or other outcropping structures, while males abandoned their webs upon adulthood to search for females. Here, we describe the life history, growth, web ontogeny, courtship and reproductive behaviors, as well as silk use of this spider for the first time. There are 11–12 instars to reach adulthood and cribellate silk did not appear in juvenile webs until the eighth instar. Interestingly, orbicularian-like behaviors were observed in the initial appearance of cribellate silk lines in the juvenile web in a spiral-like pattern. Males exhibited positive allometric growth in Leg I from penultimate to adult instars, which likely plays an important role in courtship; this included strumming the sheet, stroking the female and depositing a thin ‘bridal veil' of silk on the female. Virgin females had ‘mating plugs' prior to exposure to males. This suggests that T. perfuga may be an interesting species with which to further examine sexual evolution and female choice.

Entanglement is a costly life-history stage in large whales.

Individuals store energy to balance deficits in natural cycles; however, unnatural events can also lead to unbalanced energy budgets. Entanglement in fishing gear is one example of an unnatural but relatively common circumstance that imposes energetic demands of a similar order of magnitude and duration of life‐history events such as migration and pregnancy in large whales. We present two complementary bioenergetic approaches to estimate the energy associated with entanglement in North Atlantic right whales, and compare these estimates to the natural energetic life history of individual whales. Differences in measured blubber thicknesses and estimated blubber volumes between normal and entangled, emaciated whales indicate between 7.4 × 1010 J and 1.2 × 1011 J of energy are consumed during the course to death of a lethal entanglement. Increased thrust power requirements to overcome drag forces suggest that when entangled, whales require 3.95 × 109 to 4.08 × 1010 J more energy to swim. Individuals who died from their entanglements performed significantly more work (energy expenditure × time) than those that survived; entanglement duration is therefore critical in determining whales’ survival. Significant sublethal energetic impacts also occur, especially in reproductive females. Drag from fishing gear contributes up to 8% of the 4‐year female reproductive energy budget, delaying time of energetic equilibrium (to restore energy lost by a particular entanglement) for reproduction by months to years. In certain populations, chronic entanglement in fishing gear can be viewed as a costly unnatural life‐history stage, rather than a rare or short‐term incident.

Remarks on the Natural History of São Paulo Marsh Antwren (Formicivora paludicola)

ABSTRACT The Sao Paulo Marsh Antwren (Formicivora paludicola) is a recently discovered species in the family Thamnophilidae that inhabits marshes in the vicinity of the Sao Paulo metropolitan region, which is the most populous area of South America and within the Brazilian Southeastern Atlantic Forest. This species should be considered “Critically Endangered” following IUCN criteria, as it has a total area of occupancy of only 1.42 km2, a sparse and fragmented distribution, low dispersal capacity, and has lost ~300 km2 of habitat in the last 200 years. F. paludicola was discovered on the verge of extinction, and virtually nothing is known about its natural history, breeding biology, and life history, hence compromising any conservation effort. By capturing and banding individuals from the three largest populations of Sao Paulo Marsh Antwrens, we provide the first assessment of the breeding period and molt cycles of F. paludicola. Our observations indicate breeding season is from October to February, and t...

Reliability and Validity of the Adapted Spanish Version of the Early-onset Scoliosis-24 Questionnaire.

Translation and validation of the Early Onset Scoliosis-24 Questionnaire (EOSQ-24). To cross-culturally adapt the American English version of the EOSQ-24 into Spanish language, and to assess its reliability and discriminative validity. Treatment of early-onset scoliosis (EOS) seeks to improve natural history and health-related quality of life in children, but radiographic parameters are insufficient to evaluate the severity and efficacy of treatment in these patients. EOSQ-24 was developed to assess the health-related quality of life of EOS children; however, it has not been transculturally adapted and validated for Spanish subjects. Translation and cross-cultural adaptation of the original EOSQ-24 was performed according to published guidelines by an expert committee. The Spanish version of the EOSQ-24 was applied to 44 EOS patients. Reliability was assessed by internal consistency using Cronbach α, item-total correlations, and inter-item correlations. Data quality was assessed by mean, median, percentage of missing data, and ceiling and floor effects. For discriminative validity, comparisons between categorical variables were made by using non-parametric (Kruskal-Wallis and/or Mann Whitney U) tests, and Spearman correlation coefficients were used for continuous variables. In our study, all items and domains showed very good global internal consistencies (Cronbach α 0.897 and 0.836, respectively). Corrected item-total correlations were good for all domains (>0.3). Two of 24 items showed low corrected item-total correlations (r = 0.179 and r = 0.254), but Cronbach α did not increase when these items were removed. Inter-item correlations were acceptable (>0.2). EOSQ-24 was found capable to discriminate patients with different curves severity (P = 0.001), diagnosis (P = 0.006), and ambulatory status (P = 0.053). The Spanish version of the EOSQ-24 is reliable and a valid tool for the psychometric assessment of children with EOS, and can be applied in routine clinical practice and for research purposes. 2.

Observations of terrestrial locomotion in wild Polypterus senegalus from Lake Albert, Uganda

Polypterids, the most basal actinopterygians, are a group of fish long-considered living fossils and holding a key position for understanding fish and tetrapod evolution. Knowledge of the natural history of Polypterus is limited, their having been studied in little detail since the early 1900s. The locomotory habits of wild Polypterus senegalus from Lake Albert, Uganda, were investigated in 2014. High-speed videography demonstrated the capability of large Polypterus to move overland successfully. Contrary to previous evidence, field observations found that terrestrial locomotion in Polypterus is not inherently restricted by body size. Evidence that Polypterus exhibit this behaviour as part of their natural life history can be found in the existence of environmental challenges and the presence of adaptations for amphibious life.

Long-term assessment of clinical response to adalimumab therapy in refractory ulcerative colitis

The role of antitumour necrosis factor agents, in particular infliximab in ulcerative colitis (UC) has been well established. More recently adalimumab, a fully humanized antitumour necrosis factor α monoclonal antibody, was licensed for refractory moderately active UC in 2012. Available outcome data for adalimumab from routine clinical practice is limited. To evaluate the clinical response and remission to adalimumab in a cohort of UC patients. Patients with UC treated with adalimumab were identified from our inflammatory bowel disease database from 2007. A retrospective chart review was undertaken. Demographic and clinical data were recorded including a Mayo score and C-reactive protein (CRP) where available. All patients received standard induction subcutaneous therapy (160/80/40 mg) followed by a maintenance dose of 40 mg fortnightly. Clinical and biochemical response was assessed at 6 and 12 months. Clinical response was defined by a reduction in Mayo score more than or equal to 3, whereas clinical remission was defined by a total score of 2 or less. Dose adjustments and adverse events were also noted. In all, 52 patients were identified. Of these, 65% (n=34) were male and the mean age was 45 years (range 23-72 years). A total of 65% (n=34) had left sided disease, 31% (n=16) pancolitis and 4% (n=2) proctitis. The majority commenced adalimumab due to a loss of response to immunomodulator therapy (n=45, 87%), whereas the remaining 13% (n=7) had loss of response or been intolerant to infliximab. The mean disease duration was 8 years (1-29 years). At baseline 85% (n=44) had moderate disease and 15% (n=8) had mild disease. The baseline mean CRP was 13.5 mg/l (range 1-82 mg/l) and the mean Mayo score was 6 (range 4-10). The mean duration of treatment was 18.5 months (range 4-95 months). Follow-up data was available in 46 (88%) and 37 (71%) patients at 6 and 12 months. Overall there was a statistically significant improvement in mean partial Mayo score on follow-up; 6 months=2 [P=0.0001, 95% confidence interval (CI) 2.99-4.55], 12 months=2 (P=0.0001, 95% CI 2.74-4.46). While 65% (n=34) and 52% (n=27) had a clinical response at 6 and 12 months, respectively, 52% (n=27) and 42% (n=22) were in remission. Overall mean CRP normalized at 6 months (P=0.002, 95% CI 3.31-15.1). Of note 25% (n=13) required dose escalation during follow-up, while treatment was discontinued by seven patients, five (71%) due to a loss of response, the remaining two (29%) due to an adverse event. Our study shows adalimumab is an effective and safe long-term therapy for moderately active UC refractory to other treatments. While this data is encouraging, further work is required on patient selection and to determine the impact of treatment on both natural history and quality of life.

Natural history and quality of life in patients with cystine urolithiasis: a single centre study.

To describe the natural history and quality of life (QoL) in patients with cystine urolithiasis. A cohort study was carried out involving participants recruited from a single surgeon's case mix. Patients with cystinuria and related urolithiasis were invited to complete a questionnaire involving demographic information, use of medical treatment, surgical interventions and the 36-item short-form 36-item short-form health survey (SF-36). In all, 14 patients completed the survey. The SF-36 survey showed lower QoL than the general public in seven of eight domains. The mean interventional rate in patients with cystinuria was 10.6 procedures per patient. Most patients reported previous use of d-penicillamine and urinary alkalinisation medications, with most ceasing due to side-effects or lack of perceived efficacy. Cystinuria is associated with a high rate of surgical intervention and lower QoL than the general public. Individuals with this condition report that medical management is either ineffective or poorly tolerated. There is a need for further improvements in medical management of cystinuria, to reduce the rate of operative intervention.

Ten years of life in compost: temporal and spatial variation of North German Caenorhabditis elegans populations.

The nematode Caenorhabditis elegans is a central laboratory model system in almost all biological disciplines, yet its natural life history and population biology are largely unexplored. Such information is essential for in-depth understanding of the nematode's biology because its natural ecology provides the context, in which its traits and the underlying molecular mechanisms evolved. We characterized natural phenotypic and genetic variation among North German C. elegans isolates. We used the unique opportunity to compare samples collected 10 years apart from the same compost heap and additionally included recent samples for this and a second site, collected across a 1.5-year period. Our analysis revealed significant population genetic differentiation between locations, across the 10-year time period, but for only one location a trend across the shorter time frame. Significant variation was similarly found for phenotypic traits of likely importance in nature, such as choice behavior and population growth in the presence of pathogens or naturally associated bacteria. Phenotypic variation was significantly influenced by C. elegans genotype, time of isolation, and sampling site. The here studied C. elegans isolates may provide a valuable, genetically variable resource for future dissection of naturally relevant gene functions.

An investigation into the prevalence of exploratory behavior in captive cheetahs (Acinonyx jubatus).

Exploratory behavior in the wild is fundamentally linked to an animal's survival and natural life history. The ability to gather information about their environment, establish territories, assert dominance, communicate information regarding reproductive status and locate mates are closely associated with a range of exploratory behaviors. Understanding how these behaviors are performed within the captive setting is crucial in order to create a captive environment in which these behaviors can be expressed, and their function conserved. The objective of this research was to highlight the factors of captive husbandry and management that influence the occurrence of exploratory behaviour of cheetahs (Acinonyx jubatus) in captivity. One hundred and twelve cheetahs in 88 enclosures across nine zoological institutions in five countries were the subjects of this study. The presence of raised areas, number of movements between enclosures, group composition, sex and an interaction between group composition and the ability to view cheetahs in adjacent enclosures, all significantly influenced the prevalence of exploratory behavior in captive cheetahs. The presence of raised areas and an increasing number of movements between enclosures significantly increased the probability of observing exploratory behaviour, while this probability was significantly decreased for female cheetahs, when cheetahs were able to view conspecifics in adjacent enclosures, and were maintained in groups. A number of recommendations are discussed in relation to promoting exploratory behavior in captive cheetahs.

Methods and Accuracy of Sexing Sockeye Salmon Using Ultrasound for Captive Broodstock Management

AbstractUltrasound has been widely used to noninvasively examine the internal anatomy and reproductive status of many fish species. Since 2003, ultrasonography has been an integral part of broodstock management for Endangered Species Act–listed endangered Redfish Lake Sockeye Salmon Oncorhynchus nerka. Initial ultrasound screenings for each year's broodstock were conducted 3 to 4 months prior to anticipated maturation, before external signs of maturation developed. In keeping with the natural life history of these fish, this permitted the separation of nonmaturing fish from maturing fish so the immature fish could maintain feeding and growth. It also permitted maturing seawater‐reared fish to be transferred to freshwater for final maturation. Designing a spawning matrix to maintain genetic diversity requires knowledge of the sex of each fish before spawning. Approximately 1 month prior to spawning, a second ultrasound was performed to verify sex identification and thus ensure the accuracy of the spawning matrix. Over a 9‐year period, 2,662 fish were examined. The accuracy of sexing age‐3 adult Sockeye Salmon ranged from 94.0% to 100%, with an average of 97.7%, while the accuracy of sexing age‐4 adult fish ranged from 92.0% to 100%, with an average of 94.4%. The average accuracy was similar for fish examined in seawater or freshwater (98.1% versus 97.3%, respectively). Ultrasound was shown to be an accurate and effective tool for managing the husbandry of our captive broodstock life history.

Hydraulic Fracturing and Brook Trout Habitat in the Marcellus Shale Region: Potential Impacts and Research Needs

AbstractExpansion of natural gas drilling into the Marcellus Shale formation is an emerging threat to the conservation and restoration of native brook trout (Salvelinus fontinalis) populations. Improved drilling and extraction technologies (horizontal drilling and hydraulic fracturing) have led to rapid and extensive natural gas development in areas overlying the Marcellus Shale. The expansion of hydraulic fracturing poses multiple threats to surface waters, which can be tied to key ecological attributes that limit brook trout populations. Here, we expand current conceptual models to identify three potential pathways of risk between surface water threats associated with increased natural gas development and life history attributes of brook trout: hydrological, physical, and chemical. Our goal is to highlight research needs for fisheries scientists and work in conjunction with resource managers to influence the development of strategies that will preserve brook trout habitat and address Marcellus Shale gas development threats to eastern North America's only native stream salmonid.

The Potential of Aspen Clonal Forestry in Alberta: Breeding Regions and Estimates of Genetic Gain from Selection

BackgroundAspen naturally grows in large, single-species, even-aged stands that regenerate clonally after fire disturbance. This offers an opportunity for an intensive clonal forestry system that closely emulates the natural life history of the species. In this paper, we assess the potential of genetic tree improvement and clonal deployment to enhance the productivity of aspen forests in Alberta. We further investigate geographic patterns of genetic variation in aspen and infer forest management strategies under uncertain future climates.Methodology/Principal FindingsGenetic variation among 242 clones from Alberta was evaluated in 13 common garden trials after 5–8 growing seasons in the field. Broad-sense heritabilities for height and diameter at breast height (DBH) ranged from 0.36 to 0.64, allowing 5–15% genetic gains in height and 9–34% genetic gains in DBH. Geographic partitioning of genetic variance revealed predominant latitudinal genetic differentiation. We further observed that northward movement of clones almost always resulted in increased growth relative to local planting material, while southward movement had a strong opposite effect.Conclusion/SignificanceAspen forests are an important natural resource in western Canada that is used for pulp and oriented strandboard production, accounting for ∼40% of the total forest harvest. Moderate to high broad-sense heritabilities in growth traits suggest good potential for a genetic tree improvement program with aspen. Significant productivity gains appear possible through clonal selection from existing trials. We propose two breeding regions for Alberta, and suggest that well-tested southern clones may be used in the northern breeding region, accounting for a general warming trend observed over the last several decades in Alberta.

Spatial distribution patterns of three fig wasps on Ficus semicordata: How non-pollinators affect pollinator’s sex ratio

Sex ratio theory is one of the most productive fields in research on evolutionary biology. Pollinating fig wasps, due to their particular natural life history, are considered to be a valuable model for the study of sex ratio evolution. A great deal of research concerning the factors that affect pollinator fig wasp (Agaonidae) progeny sex ratio has been done, and at present three main factors (haplodiploidy, local mate competition and inbreeding) are found to be important at the population level. However, there still exists variation between empirical data and model predictions. Another factor to which little thought has been given before is the effect of non-pollinating fig wasps (NPFWs) which parasitize in the larvae gall of pollinator thus kill pollinators and exploit the fig/fig pollinator mutualistic systems. In this study, we focus on why and how non-pollinating fig wasps distort pollinator fig wasp’s original sex ratio. Through controlling the number of ovipositing foundresses inside a fig, combined with the observation of ovipositing behavior and sequence, we studied three species of wasp in the figs of a dioecious fig Ficus semicordata including the pollinator Ceratosolen gravely and NPFWs Platyneura cunia, Sycoscapter trifemmensis in tropical area of Xishuangbanna from September to December 2009. First, we observed the timing of oviposition of all fig wasps utilizing F. semicordata and found differences when compared to previous studies. Such as P. cunia is the fourth rather then the secondary fig wasps to oviposit on the syconia approximately 10days after the pollinator. S. trifemmensis oviposits much earlier than previously thought, 14–32days after the pollinators. We examined the spatial location of male and female progeny of the pollinator. We found foundresses of pollinator prefer to use innermost ovules first. Only at high offspring numbers were the outer ovules used. More male pollinator offspring were developed near the fig cavity, while female pollinator offspring were more evenly distributed among ovule layers. As pollinator offspring numbers increased, this phenomenon became more pronounced. This pattern of segregation of male larvae gall in inner ovules and female larvae gall in outer ovules suggests that female offspring might be more vulnerable to attack by parasitic wasps that oviposit from outside the syconium. Experiments later demonstrated that NPFWs are restricted by their ovipositor length and they prefer to or can only lay their eggs into ovules near the fig wall. Then we examined the spatial location of NPFWs and compared this with the spatial location of male/female progeny of pollinator. NPFWs had a high probability of parasitizing female pollinator larvae. Thus, NPFWs have a substantial effect on the sex ratio of the pollinator, as parasitism risk decreases towards the center of the syconium, where inner ovules provide enemy-free space for most of male pollinator offspring. Partial correlation analyse shows that sex ratio of pollinator progeny has a positive relationship with the number of NPFWs. We suggest that the resulting gradient in offspring viability between male and female contributes to selection on pollinators’ for a less female-biased sex ratio. When the affect of NPFWs was excluded, the pollinator sex ratio was not in good agreement with local mate competition theory, although it was still female-biased. In addition, the average number of offspring per foundress decreased with increasing foundress number, but pollinator sex ratio was positively related to brood size. Thus, pollinator females do not appear to adjust their sex ratio to foundress density directly, but use brood size and foundress density simultaneously as cues to assess potential LMC.

Intensification of shellfish exploitation: evidence of species-specific deviation from traditional expectations

As modern humans grapple with the repercussions of their extensive environmental impacts, archaeologists are increasingly looking toward the past to understand the nature and extent of prehistoric human impact on the environment. Many researchers rely heavily on archaeological correlates of resource intensification as a proxy measures of resource depletion, a profound and often catastrophic human impact. However, the traditional conceptualization of the archaeological correlates of shellfish intensification disregards a large amount of species-specific variation. This paper presents archaeomalacological data from Santa Cruz Island, California. The shell midden deposits CA-SCRI-480 contain a high density of Tivela stultorum (Pismo clam). Statistical analysis of the shellfish assemblage reveals significant variation in both the size and quantity of Pismo clam that people collected through time. This paper investigates this unique patterning with due consideration of the natural ecology and life history of the species and illustrates species-specific deviation from the traditional archaeological correlates of shellfish intensification. Increased collaboration with ecologists and biologists can help refine models of intensification when necessary in order create more sophisticated understanding of prehistoric human–resource interactions.

Measuring Quality of Life in Children With Early OnsetScoliosis

Treatment of children with early onset scoliosis (EOS) seeks to improve natural history and health related quality of life (QOL). QOL measurement presents a significant challenge given the young age, comorbidities, and heterogeneity of this population. The purpose of this study is to develop a disease specific measure reflecting issues of importance to EOS patients and caretakers that is responsive to clinical and treatment changes. Review of the literature and relevant measures informed development of semistructured qualitative interviews. Interviews of caregivers of EOS patients were interpreted through the framework technique. A masterlist of 75 items was created and responses were scaled on a 5-point Likert scale. Psychometric analysis was carried out to group items into domains, to maintain score distribution, to create a responsive instrument, and to identify question redundancy. Content validation showed 8 items with low content validity indices (<0.70). Item distribution analysis showed 19 items with skewed distribution. Item reliability showed redundant items within domains (r≥0.5). Construct validity showed unique domains measuring intended issues of interest. The resulting Early Onset Scoliosis Questionnaire (EOSQ) includes 33 items in 13 domains: General Health, Pain, Physical Function, Pulmonary Function, Daily Living, Fatigue, Emotion, Surgical Concerns, Satisfaction, Transfer, Financial Burden, Parental Burden, and Treatment Outcomes. The EOSQ reflects QOL and caregiver burden in the EOS population. The EOSQ will expand options for outcome assessment in this unique population.

Rapid evolutionary innovation during an Archaean genetic expansion

The natural history of Precambrian life is still unknown because of the rarity of microbial fossils and biomarkers. However, the composition of modern-day genomes may bear imprints of ancient biogeochemical events. Here we use an explicit model of macroevolution including gene birth, transfer, duplication and loss events to map the evolutionary history of 3,983 gene families across the three domains of life onto a geological timeline. Surprisingly, we find that a brief period of genetic innovation during the Archaean eon, which coincides with a rapid diversification of bacterial lineages, gave rise to 27% of major modern gene families. A functional analysis of genes born during this Archaean expansion reveals that they are likely to be involved in electron-transport and respiratory pathways. Genes arising after this expansion show increasing use of molecular oxygen (P = 3.4 × 10(-8)) and redox-sensitive transition metals and compounds, which is consistent with an increasingly oxygenating biosphere.

Effects of stress and motivation on performing a spatial task

Learning is ubiquitous in the animal kingdom but has been studied extensively in only a handful of species. Moreover, learning studied under laboratory conditions is typically unrelated to the animal’s natural environment or life history. Here, we designed a task relevant to the natural behavior of male African cichlid fish (Astatotilapia burtoni), to determine if they could be trained on a spatial task to gain access to females and shelter. We measured both how successfully animals completed this task over time and whether and how immediate early gene and hormone expression profiles were related to success. While training fish in a maze, we measured time to task completion, circulating levels of three key hormones (cortisol, 11-ketotestosterone, and testosterone) and mRNA abundance of seven target genes including three immediate early genes (that served proxies for brain activity) in nine brain regions. Data from our subjects fell naturally into three phenotypes: fish that could be trained (learners), fish that could not be trained (non-learners) and fish that never attempted the task (non-attempters). Learners and non-learners had lower levels of circulating cortisol compared to fish that never attempted the task. Learners had the highest immediate early gene mRNA levels in the homologue of the hippocampus (dorsolateral telencephalon; Dl), lower cortisol (stress) levels and were more motivated to accomplish the task as measured by behavioral observations. Fish that never attempted the task showed the lowest activity within the Dl, high stress levels and little to no apparent motivation. Data from non-learners fell between these two extremes in behavior, stress, and motivation.

Effects of temperature and irradiance on early development of Chondrus ocellatus Holm (Gigartinaceae, Rhodophyta)

Chondrus is a type of commercially produced red seaweed that widely used for food and carrageen extraction. Although the natural life history of the alga had been well understood, the factors influencing development of the tetraspore and carpospore remain poorly understood. In the perspective of seedling resources, the regulation of early development is crucial for the seedling nursing; therefore, it is necessary to understand the physiological influences during its early development. In this study, we studied the effects of temperature and irradiance on the early development of Chondrus ocellatus Holm under laboratory conditions. The released tetraspores and carpospores were cultivated at different temperatures (10-28 degrees C) and irradiances ( 10, 60 mu mol photons m(-2)s(-1)) with a photoperiod of 12L:12D. The results indicate that both tetraspores and carpospores are tolerant to temperatures of 10-25 degrees C, and have the highest relative growth rate at 20 degrees C. Irradiance variances influenced the growth of the discoid crusts, and the influence was more significant with increasing temperature; 60 mu mol photons m(-2)s(-1) was more suitable than 10 mu mol photons m(-2)s(-1). The optimum temperature and irradiance for the development of seedlings was 20 degrees C and 60 mu mol photons m(-2)s(-1), respectively.

The natural life history of a lottery: the importance of large wins in the establishment and survival of a lottery

Historically, governments have often used lotteries as an alternative form of revenue generation. In this paper, we examine the life history of the Canadian Lotto 649 by examining sales figures from the lifespan of this popular lottery product. The examination of the early days of the lottery revealed the importance of large jackpots in establishing the lottery. Over time, competition and small jackpots were associated with a drop in ticket sales. An increase in the price of the tickets in 2004 resulted in a decrease in the number of tickets actually sold, an increase in the size of the jackpot and an increase in revenue. The results of this study highlight the importance of large jackpots in establishing, maintaining, and revitalising this lottery product.